text:
Mathematical symbols/Chart

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Plus sign

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Plus or minus sign

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Mathematical symbols/Chart


text:
LMIs in Control/Matrix and LMI Properties and Tools/Iterative Convex Overbounding

Iterative convex overbounding is a technique based on Young’s relation that is useful when solving an optimization problem with a BMI constraint.

The System
Consider the matrices $$ Q=Q^{T}\in \mathbb{R}^{n\times n}, B \in \mathbb{R}^{n\times m}, R \in \mathbb{R}^{m\times p}, D \in \mathbb{R}^{p\times q},S \in \mathbb{R}^{q\times r} and C \in \mathbb{R}^{r\times n}$$, where S and R are design variables in the BMI given by

\begin{align} \qquad Q + BRDSC + C^{T}S^{T}D^{T}R^{T}B^{T} < 0      \qquad    (1)\\ \end{align}                              $$

The LMI:Iterative Convex Overbounding
Suppose that S0 and R0 are known to satisfy (1). The BMI of (1) is implied by the LMI
 * $$\begin{bmatrix}

Q+\phi(R,S)+\phi^{\text{T}}(R,S) & B(R-R0)U &C^{\text{T}}(S-S0)^{\text{T}}V^{\text{T}}\\ \end{bmatrix} < 0 \qquad   (2) $$ where Φ(R,S) = B(RDS0+R0DS-R0DS0)C, W>0 is an arbitrary matrix, D=UV, and the matrices U and VT have full column rank. The LMI of (2) is equivalent to the BMI of (1) when R = R0 and S = S0, and is therefore non-conservative for values of R and S and are close to the previously known solutions R0 and S0.
 * &W^{\text{-1}}&0\\
 * &*&-W\\

Alternatively, the BMI of (1) is implied by the LMI
 * $$\begin{bmatrix}

Q+\phi(R,S)+\phi^{\text{T}}(R,S) &Z^{\text{T}}U^{\text{T}}(R-R0)^{\text{T}}B^{\text{T}}+V(S-S0)C\\
 * &Z\\

\end{bmatrix} < 0 \qquad   (3) $$ where Z > 0 is an arbitrary matrix, D = UV, and the matrices U and VT have full column rank. Again, the LMI of (4) is equivalent to the BMI of (2) when R = R0 and S = S0, and is therefore non-conservative for values of R and S and are close to the previously known solutions R0 and S0.

Conclusion:
A benefit of convex overbounding compared to a linearization approach, is that in addition to ensuring conservatism or error is reduced in the neighborhood of R = R0 and S = S0, the LMIs of (2) and (3) imply (1). Iterative convex overbounding is particularly useful when used to solve an optimization problem with BMI constraints.


text: Advanced Structural Analysis/Printable version


text:
LMIs in Control/Matrix and LMI Properties and Tools/Strict Projection Lemma

Introduction
Projection Lemma is also known as Matrix Elimination Lemma. Strict Projection Lemma is one of the characteristics of the Projection Lemma.

Strict Projection Lemma
Consider $$\Psi\in \mathbb{S}^n$$, $$ G\in \mathbb{R}^{n\times m}$$, $$\Lambda\in \mathbb{R}^{m\times p}$$, and $$ H\in \mathbb{R}^{n\times p}.$$ There exists $$\Lambda $$ such that:

$$ \begin{align} \ \Psi + G \Lambda H^T + H \Lambda^T G^T<0, \end{align} $$

if and only if,

$$ \begin{align} \ N_G^T \Psi N_G <0 \end{align} $$,

$$ \begin{align} \ N_H^T \Psi N_H <0 \end{align} $$,

where $$\mathcal{R} (N_G) =\mathcal{N} (G^T)$$ and $$\mathcal{R} (N_H) = \mathcal{N} (H^T)$$.


text:
LMIs in Control/Matrix and LMI Properties and Tools/Non Strict Projection Lemma

Introduction
Projection Lemma is also known as Matrix Elimination Lemma. Strict Projection Lemma is one of the characteristics of the Projection Lemma.

Non Strict Projection Lemma
Consider $$\Psi\in \mathbb{S}^n$$, $$ G\in \mathbb{R}^{n\times m}$$, $$\Lambda\in \mathbb{R}^{m\times p}$$, and $$ H\in \mathbb{R}^{n\times p}.$$, where $$ \mathcal{R} (G)$$ and $$ \mathcal{R} (H)$$ is linear;y independent. There exists $$\Lambda $$ such that:

$$ \begin{align} \ \Psi + G \Lambda H^T + H \Lambda^T G^Tleq0, \end{align} $$

if and only if,

$$ \begin{align} \ N_G^T \Psi N_G \leq0 \end{align} $$,

$$ \begin{align} \ N_H^T \Psi N_H \leq0 \end{align} $$,

where $$\mathcal{R} (N_G) =\mathcal{N} (G^T)$$ and $$\mathcal{R} (N_H) = \mathcal{N} (H^T)$$.


text:
LMIs in Control/Matrix and LMI Properties and Tools/Concatenation Of Matrices

Introduction
Matrix concatenation is the process of joining one or more matrices to make a new matrix. This process is similar for concatenating the LMIs as well.

Concatenation of LMIs
A useful property of LMIs is that multiple LMIs can be concatenated together to form a single LMI. For example, satisfying the LMIs $$ A < 0$$ and, $$B < 0$$ is equivalent to satisfying the concatenated LMI:

$$ \begin{bmatrix} A && 0 \\ 0 && B \end{bmatrix}$$ $$\begin{align} <0 \end{align}$$,

More generally, satisfying the LMIs $$Ai < 0$$, where $$i = 1,. . ., n $$ is equivalent to satisfying the concatenated LMI:

$$ \begin{bmatrix} A && 0 && 0 &&. && . && 0 \\ 0 && B && 0 &&. && . && 0 \\ 0 && 0 && C &&. && . && 0 \\ . && . && . && . && . && 0\\ . && . && . && . && . && 0 \\ 0 && 0 && 0 && 0 && 0 && A_n\\ \end{bmatrix}$$ $$\begin{align} <0 \end{align}$$,


text:
Hacking/Reconnaissance

A network reconnaissance methods can be passive or active.

Passive methods:, , , , , ,.

Active methods:, , ning, ing. Crackers strive to minimize

Sniffing
A 'wireless' can find es, which is helpful for network mapping.

Access points usually connect the nodes of a wireless network to a wired network as a bridge or a router. Both a bridge and a router use a routing table to forward packets.

Finding relevant and reachable IP addresses is the objective of the reconnaissance phase of attacking an organization over the Internet. The relevant IP addresses are determined by collecting as many host names as possible and translating them to IP addresses and IP address ranges. This is called footprinting.

A is the key for finding as much information as possible about a target. In many cases, organizations do not want to protect all their resources from internet access. For instance, a must be accessible. Many organizations additionally have, servers, and other systems that must be accessible over the internet. The IP addresses of an organization are often grouped together. If one IP address has been found, the rest probably can be found around it.

s store tables that show how domain names must be translated to IP addresses and vice versa. With Windows, the command can be used to query DNS servers. When the word help is entered at NSLookup's prompt, a list of all commands is given. With Linux, the command dig can be used to query DNS servers. It displays a list of options when invoked with the option -h only. And the command host reverses IP addresses to hostnames. The program can be used as a reverse DNS walker: nmap -sL 1.1.1.1-30 gives the reverse entries for the given range.

ARIN, RIPE, APNIC, LACNIC, and AFRINIC are the five that are responsible for the assignment and registration of IP addresses. All have a website with which their databases can be searched for the owner of an IP address. Some of the Registries respond to a search for the name of an organization with a list of all IP address ranges that are assigned to the name. However, the records of the Registries are not always correct and are in most cases useless.

Probably most computers with access to the internet receive their IP address dynamically by. This protocol has become more popular over the last years because of a decrease of available IP addresses and an increase of large networks that are dynamic. DHCP is particularly important when many employees take a portable computer from one office to another. The router/ device that people use at home to connect to the internet probably also functions as a DHCP server.

Nowadays many router/DHCP devices perform (NAT). The NAT device is a between the local network and the internet. Seen from the internet, the NAT device seems to be a single host. With NAT, the local network can use any IP address space. Some IP address ranges are reserved for s. These ranges are typically used for the local area network behind a NAT device, and they are: 10.0.0.0 - 10.255.255.255, 172.16.0.0 - 172.31.255.255, and 192.168.0.0 - 192.168.255.255.

The relevant IP addresses must be narrowed down to those that are reachable. For this purpose, the process of scanning enters on the scene.

Host scanning
Once access to a wireless network has been gained, it is helpful to determine the network's topology, including the names of the computers connected to the network. can be used for this, which is available in a Windows and a Linux version. However, Nmap does not provide the user with a network diagram. The network scanner Network View that runs on Windows does. The program asks for one IP address or an IP address range. When the program has finished scanning, it displays a map of the network using different pictures for routers, s,, and s, all with their names added.

The most direct method for finding hosts on a is using the program. When using a modern flavour of, commands can be combined to produce custom. When using Windows, the command-line can also be used to create a ping-sweep. Examples are given in the reference.

Ping-sweeps are also known as host scans. Nmap can be used for a host scan when the option -sP is added:	nmap -n -sP 10.160.9.1-30 scans the first 30 addresses of the subnet 10.160.9, where the -n option prevents reverse DNS lookups.

Ping packets could reliably determine whether a computer was on line at a specified IP address. Nowadays these echo request packets are sometimes blocked by the firewall of an. Although Nmap also probes TCP port 80, specifying more TCP ports to probe is recommended when pings are blocked. Consequently, nmap -sP -PS21,22,23,25,80,139,445,3389 10.160.9.1-30 can achieve better results. And by combining various options as in nmap -sP -PS21,22,23,25,80,135,139,445,1025,3389 -PU53,67,68,69,111,161,445,514 -PE -PP -PM 10.160.9.1-30, superb host scanning is achieved.

Nmap is available for Windows and most Unix operating systems, and offers graphical and command-line interfaces.

Port scanning
The purpose of port scanning is finding the open ports on the computers that were found with a host scan. When a port scan is started on a network without making use of the results of a host scan, much time is wasted when many IP addresses in the address range are vacant.

Open ports
Most programs that communicate over the Internet use either the or the  protocol. Both protocols support 65536 so called  that programs can choose to bind to. This allows programs to run concurrently on one IP address. Most programs have default ports that are most often used. For example, HTTP servers commonly use TCP port 80.

Network scanners try to connect to TCP or UDP ports. When a port accepts a connection, it can be assumed that the commonly bound program is running.

TCP connections begin with a SYN packet being sent from client to server. The server responds with a SYN/ACK packet. Finally, the client sends an ACK packet. When the scanner sends a SYN packet and gets the SYN/ACK packet back, the port is considered open. When a RST packet is received instead, the port is considered closed. When no response is received the port is either considered filtered by a firewall or there is no running host at the IP address.

Scanning UDP ports is more difficult because UDP does not use handshakes and programs tend to discard UDP packets that they cannot process. When an UDP packet is sent to a port that has no program bound to it, an ICMP error packet is returned. That port can then be considered closed. When no answer is received, the port can be considered either filtered by a firewall or open. Many people abandoned UDP scanning because simple UDP scanners cannot distinguish between filtered and open ports.

Common ports
Although it is most thorough to scan all 65536 ports, this would take more time than scanning only the most common ports. Therefore, Nmap scans 1667 TCP ports by default (in 2007).

Specifying ports
The -p option instructs Nmap to scan specified ports, as in nmap -p 21-25,80,100-160 10.150.9.46. Specifying TCP and UDP ports is also possible, as in nmap -pT:21-25,80,U:5000-5500 10.150.9.46.

Specifying targets
Nmap always requires the specification of a host or hosts to scan. A single host can be specified with an IP address or a domain name. Multiple hosts can be specified with IP address ranges. Examples are 1.1.1.1, www.company.com, and 10.1.50.1-5,250-254.

Specifying scan type
TCP SYN scan Nmap performs a TCP SYN scan by default. In this scan, the packets have only their SYN flag set. The -sS option specifies the default explicitly. When Nmap is started with administrator privileges, this default scan takes effect. When Nmap is started with user privileges, a connect scan is performed.

TCP connect scan The -sT option instructs Nmap to establish a full connection. This scan is inferior to the previous because an additional packet must be sent and logging by the target is more likely. The connect scan is performed when Nmap is executed with user privileges or when IPv6 addresses are scanned.

TCP null scan The -sN option instructs Nmap to send packets that have none of the SYN, RST, and ACK flags set. When the TCP port is closed, a RST packet is sent in return. When the TCP port is open or filtered, there is no response. The null scan can often bypass a stateless firewall, but is not useful when a stateful firewall is employed.

UDP empty packet scan The -sU option instructs Nmap to send UDP packets with no data. When an ICMP error is returned, the port can be assumed closed. When no response is received, the port can be assumed open or filtered. No differentiation between open and filtered ports is a severe limitation.

UDP application data scan The -sU -sV options instruct Nmap to use application data for application identification. This combination of options can lead to very slow scanning.

Other options
Other options

Specifying scan speed When packets are sent to a network faster than it can cope with they will be dropped. This leads to inaccurate scanning results. When an intrusion detection system or intrusion prevention system is present on the target network, detection becomes more likely as speed increases. Many devices and firewalls respond to a storm of SYN packets by enabling  that make appear every port to be open. Full speed scans can even wreak havoc on.

Nmap provides five templates for adjusting speed and also adapts itself. The -T0 option makes it wait for 5 minutes before the next packet is sent, the -T1 option makes it wait for 15 seconds, -T2 inserts 0.4 seconds, -T3 is the default (which leaves timing settings unchanged), -T4 reduces time-outs and retransmissions to speed things up slightly, and -T5 reduces time-outs and retransmissions even more to speed things up significantly. Modern IDS/IPS devices can detect scans that use the -T1 option. The user can also define a new template of settings and use it instead of a provided one.

Application identification The -sV option instructs Nmap to also determine the version of a running application.

Operating system identification The -O option instructs Nmap to try to determine the operating systems of the targets. Specially crafted packets are sent to open and closed ports and the responses are compared with a database.

Saving output The -oX option instructs Nmap to save the output to a file in format.

See also
 * Nmap

Vulnerability scanning
Vulnerability scanning determines whether known vulnerabilities are present on a target. A vulnerability is a bug in an application program that affects security. They are made public on places such as the Full-Disclosure mailing list. The (CERT) brings out a statistical report every year.

 s:

 * http://www.PacketStormSecurity.org/ —
 * http://www.exploit-db.com/ —

Tools

 * https://www.offensive-security.com/metasploit-unleashed/information-gathering/
 * https://docs.rapid7.com/metasploit/discovery-scan
 * https://www.bettercap.org/modules/ethernet/net.recon/
 * https://www.bettercap.org/modules/ethernet/net.sniff/
 * https://www.bettercap.org/modules/ethernet/net.probe/

title: Hacking/Reconnaissance


text:
Lentis/Vision Zero

Introduction
Vision Zero is a movement to eliminate all traffic deaths and severe injuries. It differs from the traditional approach to traffic safety in two major ways. First, it recognizes people will make mistakes, thus road systems must be designed to ensure those mistakes don't result in deaths or severe injuries. Second, it uses a multidisciplinary approach bringing together traffic planners, engineers, policy makers, and public health professionals to address this complex problem. It began in Sweden in 1997 when the Swedish parliament adopted it as the official road policy. After adopting it, traffic deaths were cut in half even while the number of trips increased. Since then, cities in countries around the world have adopted the Vision Zero concept. Its techniques, like using choice architecture and finding aligning interests, can be applied to many other problems today.

Participants
Vision Zero has been adopted by many places in Europe like Sweden, Norway, The Netherlands and London, England. It has also spread outside of Europe to places like Australia, New Zealand and the United States. As of August 2021, 51 cities in the United States partake in Vision Zero and are shown on the Vision Zero Network map.

Importance
Each year in the United States, more than 40,000 people are killed by cars and thousands more are injured. This number worldwide is around 1.35 million. Traditionally, society has assumed this to be an inevitable side effect of modern transportation. We have called these tragedies traffic "accidents" when in reality they can be prevented through being proactive and prioritizing traffic safety as a public health issue.

Key Priorities
All communities that participate in Vision Zero uphold three key priorities.

 * 1) Managing Speed
 * 2) * Speeding kills more than 10,000 people each year in the United States. Drunk driving kills about the same number of people; however, speeding doesn't carry nearly the same social consequences as drunk driving. Vision Zero prioritizes safe speeds through automating speed enforcement (safety cameras), setting safe speed limits, and designing safe streets.
 * 3) Centering Equity
 * 4) * Vision Zero believes that safe mobility is a basic human right and that communities should invest in safety strategies that ensure equity. This means prioritizing those communities that have a disproportionately high rate of traffic deaths and serious injuries.
 * 5) Engaging Communities
 * 6) * City officials should work with community based organizations that have public trust and respect to figure out what needs are the greatest for traffic safety in each community.

Getting Involved/Recognized
If a community is interested in getting involved with and recognized by Vision Zero, they start by filling out a questionnaire. The mayor or highest city official would fill out the form, which consists of 39 questions gauging their community's commitment to the movement. Within two weeks of completing the questionnaire, the Vision Zero Network will contact the community. All communities must meet five minimum criteria to become recognized by the network:

 * 1) Have a clear goal of eliminating traffic deaths within an explicit timeframe (i.e. 10 years)
 * 2) The mayor or highest official is publicly committing to Vision Zero and directing appropriate city staff
 * 3) A Vision Zero strategy is in place
 * 4) Key city departments are actively engaged in the plan
 * 5) A Vision Zero Task Force meets regularly to lead and evaluate efforts

If the community meets these minimum criteria, they will be recognized by the Vision Zero Network. Recognized communities are added to the Network's online map of participating communities as well as invited to participate in calls, webinars, conferences, a listserv and in-person meetings. Being recognized is also a public statement of your community's commitment to making roads safe for everyone.

Opposition
While anyone would support eliminating traffic deaths, many are skeptical of Vision Zero's practicality. Others are opposed to certain methods used to achieve Vision Zero. A common critique is that since Vision Zero is a goal without one "proper" way of being implemented, it is easy for a city to adopt Vision Zero without progressing towards the goal. Los Angeles, Washington D.C., and Chicago are three commonly given examples of such cities. Some people support Vision Zero in theory but remain critical of solutions that have been offered in its name.

Many drivers who want less restrictive driving laws oppose Vision Zero. One of the first Vision Zero actions taken in New York City involved reducing the speed limit on every road to 25mph. This earned backlash from some who were frustrated with the already-slow city traffic. Similar opposition to stricter driving regulations caused Los Angeles to cancel plans to directly reduce driving in favor of less-intrusive actions such as repairing sidewalks. Some people have claimed that Vision Zero's methods are not intended to lower traffic fatalities, but rather to generate city revenue.

Norway
Norway has been a Vision Zero world leader since it began practicing in 2002. In 2019, Norway had the fewest traffic related deaths per million at 20, while the average in Europe was 51. In 2020, these values dropped to 17 in Norway and 42 in Europe. Its capital city of Oslo has made major changes to its roadways to improve safety for drivers, bicyclists, and pedestrians that led to only one road related death in 2019 from a driver who drove his car into a fence. Since 2015, when Oslo seriously started pushing for safer roads, it has added about 50 new kilometers of bike lanes throughout the city, and there are plans for 25 more kilometers to be added starting in 2022. Adding these cycling paths often comes at the cost of street parking for cars. Usually the renovations do not expand upon the streets, but instead they are repurposed. Much of the success towards achieving Vision Zero in Oslo is not about making streets safer for cars, but rather it comes from disincentivizing driving and making alternative modes of transport, like public transit or cycling, more appealing.

France
Paris, France is making great strides towards becoming another world leader in Vision Zero. They have introduced many of the same practices as Norway when it comes to promoting alternatives modes of transport, and they even have plans to become a 100 percent cycling city by 2026. Many of the best practices for achieving success in Vision Zero involve promoting less use of personal vehicles since lower car usage means lower accident and death tolls. But sometimes it is not feasible for people to drive less, such as in a rural, more spread out area. In cases like this, improving safety for drivers is necessary to reduce fatalities. To do this, France has implemented over 30,000 roundabouts throughout the country. Of these 30,000 roundabouts, about 80 percent of them have never had an accident occur within them.

United States
While the U.S. has a long way to go in reducing their road related deaths rate (124 per million in 2019), there are a few bright spots within the country. Carmel, Indiana, while not an official Vision Zero participant, may be the closest city in the U.S. to achieving Vision Zero. Like France, Carmel began using roundabouts throughout the city starting around 1996. There are now over 140 roundabouts in Carmel (compared to 15 traffic lights), and its road related death rate is on par with Norway at 20 deaths per million (2 per 100,000). Since beginning to use roundabouts in the city, Carmel's traffic fatality rate has fallen by 90 percent. Roundabouts are safer than signalized intersections because they have fewer conflict points, and most crashes will be side swipes rather than T-bones which are much more dangerous. Roundabouts are a great option for improving safety in an area where people still need to drive and commute longer distances.

Applications
Many of the techniques used by the Vision Zero movement, such as reducing speed limits or converting car lanes into bike lanes, are clear applications of a concept called "choice architecture". This term was first coined in 2008 by Richard Thaler and Cass Sunstein, although the idea is much older. Choice architecture is the practice of designing a system in a way that silently encourages users to make certain decisions which the designer deems more preferable. In the example of Vision Zero, proponents intentionally design the cities to encourage people to use safer methods of transportation, such as cycling. Choice architecture is a powerful tool that can help solve many issues because it maintains system users' ability to make decisions, meaning it is often better received than more directly intervening methods.

While Vision Zero aims to eliminate traffic deaths, many strategies it employs are ones that can help solve other issues too. This enables Vision Zero to gain support from a much broader audience, rather than just those fighting traffic deaths. For example, rather than just focusing on safer cars or roads, Vision Zero has put much emphasis on encouraging bike-friendly cities. This reduces traffic deaths as desired, and also gains the support of groups focused on lowering carbon-emissions or promoting cycling. This can be seen in the European Cyclists' Federation (ECF), a group involved in the transformation of Oslo, whom advocates primarily for cycling and only sees safety as one part of its agenda.

title: Lentis/Vision Zero


text: Category:Aladdin Malikov

title: Category:Aladdin Malikov


text: Category:Book:Aladdin Malikov/Bibliography


text: Template:The Lyrics of Henry VIII/Navigation


text: Category:Book:The Lyrics of Henry VIII/Templates


text:
Lentis/Augmented Reality in Medicine

Overview
Augmented reality (AR) is the enhancement of a user's field of view through superimposed computer generated data on a display system. AR is becoming more accessible and affordable, with increasing relevance to many sectors of the economy in the near future. AR has been used in medicine since the early 2000s, but has not seen rapid growth and development. Its use in medicine creates an interesting intersection between technology and society as the technology gains prominence in the modern world.

Current Applications
AR has seen limited use in medicine until very recently. Many more applications will likely arise in the near future as new innovations occur, as the price and computing power required for AR has decreased continuously since its invention in 1957. This will allow for more hospitals and universities to adopt the technology for current use in a variety of ways.

Student Training Applications
The use of AR in medical training dates back to the early 2000s. AR has mainly been used for surgical training but has also been applied to numerous other areas of health science. The main roles of AR in student trainings include: navigation and guidance through surgeries, feedback on doctor's progress, remote assessment and training, and simulator practice, while providing an innovative user-interface for trainees. Training has been developed into apps (such as ARnatomy) that can be completed remotely for improved training, e.g. during a pandemic. Swanwick and Buckley note "medical education now, more so than in the past, needs to span three sectors: undergraduate, postgraduate and the continuing professional development of established clinicians." They also found that 96% of training methods studied found AR to be improving healthcare education.

Clinical Care
AR is used in the dentistry industry mainly through smart glasses. Headsets and smart glasses enhance dentistry by providing the user with the patient's information displayed in a HUD (heads up display) system in front of their vision. This allows for quick access to data providing useful information and saving time for the patient and doctor. AccuVein also uses AR to create a virtual map of a patient's vasculature on their skin improving patient comfort during venipuncture procedures. Augmedics is a company developing AR headsets for use in spinal surgery. Their xvision headsets have helped surgeons complete spinal surgeries in over 200 cases since 2020. The xvision Spine system (XVS) "allows surgeons to visualize their patients’ 3D spinal anatomy during surgery as if they had “x-ray vision,” helping them to accurately navigate instruments and implants while looking directly at the patient, rather than a remote screen."

Better Visualizations
AR allows for enhanced perception of medical conditions through the use of projection and mapping. This allows for improved patient to doctor communication during the initial treatment stages and aids in descriptions of surgical procedures to patients. The use of AR also makes telehealth appointments more feasible because people are able to have effective communication while looking through a shared point of view without being in the same room.

Future Applications
Currently, AR is mostly used for surgery and anatomy skill building exercises but that is likely to change as innovations occur. AR has an extraordinary amount of potential in the medical field, but it's not purely the technology itself that attracts attention; it additionally holds potential as a "stepping stone" to potentially revolutionary future technologies.

Linked Realities
Linked realities lets multiple people see the same virtual augmentations cohesively. This would enable multiple AR systems in the operating room to allow everyone to view the same projections. Furthermore, it could allow surgical experts to give advice remotely; the advisor would use a computer or gloves that project hands into the operating theater through the surgeon's AR goggles. This technology allows for multiple experts, across the world if needed, to be consulted, giving accurate advice and preventing miscommunication.

Technical Challenges
While AR has great potential in medical innovation, there are many obstacles to the development of AR technology.

Poor Business Model
As of right now AR has no solid marketing basis. There is nothing that AR does, in its current state, that other technologies cannot do better. This slows investment and disrupts development. To further develop AR, companies need to determine their niche ability that can't be matched by modern technology in use.

Accuracy of Projection
The accuracy of the projections is another major problem. AR needs to project a three dimensional image using a two dimensional screen, while the user is moving in real time, with near one hundred percent reliability. If the technology can't do this at a minimum then there is no way it can be used in any future application besides a useful teaching tool.

Newness of technology
AR is an extraordinarily new application being used in medicine and currently has minimal uses and applications in other sectors. Because of this, many people are wary of it. Before it can improve, it needs to be accepted by the general public. Until recently, AR systems had to be run on large bulky platforms which isn't feasible to use in a surgical room. Now that the technology required is becoming smaller, there's more potential for its uses to expand.

Dangers of Augmented Reality in Medicine
As a novel technology, certain risks could potentially impact the rollout of AR.

Learning Deficiencies and "Deskilling"
Deskilling is a reduction in worker autonomy, knowledge, and decision-making ability, often attributed to innovations designed to improve efficiency, reduce cost, and standardize procedures. While the concept was first applied to the medical field in the Seventies, the difficulty of measuring deskilling has made consensus difficult - another issue is that deskilling is overwhelmingly portrayed as a struggle between workers and management, which divides analysis of deskilling as a phenomenon along ideological lines and further muddles efforts to measure its incidence. In a study conducted through interview, physicians using electronic medical records and clinical guidelines have reported decreased confidence, patient trust, and clinical knowledge ; there is concern that these phenomena would occur with the use of AR technology, at a potentially more dangerous scale.

Dependency
In addition to the concept of deskilling, physicians using technological innovations were found to adapt to the technologies available but concurrently build a reliance - accordingly there is a concern that the same issue would apply to AR applications. This is of particular significance with VR and AR, as per their names, modifying reality - rather than simply losing a "tool" in operations, losing an item used to process and re-contextualize reality may feel more like losing a "sense," with great potential patient risk.

Ethical Implications
The ethical implications of advanced technology, particularly AI, VR, and AR, are matters currently facing significant scrutiny ; when taken in conjunction with the strict ethical standards of the medical field the issue becomes one of great importance. One fundamental issue associated with the increased data-gathering capabilities is that of privacy. While medical data in aggregate has great potential to provide significant benefits, on an individual level it is imperative that individual privacy is respected as it pertains to medical information. Initial approaches to discussing the former have been suggested on a patient-caregiver level, with one concept being a system of storing genome sequences which can be adjusted based on caregiver and patient discussion, with stated aim of increasing awareness of personal information in patients.

In addition to the technological aspects, the psychological concerns of VR and AR are worth further consideration - studies have indicated that the felt environment in VR has had unconscious influences on human behavior - how these behavioral changes impact the relatively reality-reflective use of AR in medicine is a matter worthy of examination ; one speculative example might be a change in confidence - whether to a level of calm reassurance or toward a dangerous level of overconfidence is a question for the future.

Conclusion
The expansion of AR into medicine is a field with great potential and great risk. As new technologies enter the medical field, they offer potential for innovations which can improve efficiency and effectiveness, but at the same time carry new challenges and risk generating a new set of problems to accompany their solutions. The newness of the technology is one element which has great potential - as time goes on and both quality and adaptation of the technology improve allowing innovations to occur. With this expansion, there will likely be a significant number of interest groups which do not exist yet worth examining, and perhaps more detailed examination of the deskilling and dependency concerns that are present today, as that technology spreads.

title: Lentis/Augmented Reality in Medicine


text:
Carnatic Music/Speeds

The first speed is the slowest. The second speed is twice as fast as the first, the third speed twice as fast as the second, and so on. It is recommended for the first speed to be 4 seconds per beat.

Adhi Thalam
The examples below are one beat each:
 * s
 * 1) s r
 * 2) s r g m
 * 3) s r g m p d n S

Incomplete Counts in Varisais (Songs)
If at the end of a varisai you have not finished the thalam repeat, you must do either of the following:
 * repeat the varisai
 * sing the varisai's last two lines

title: Carnatic Music/Speeds


text:
User:Editororsomethingidk

yo ima librarian woooooooooooooooooooooooooooooooooooooooo

title: User:Editororsomethingidk


text:
LMIs in Control/Matrix and LMI Properties and Tools/Young’s Relation-Based Properties

Young’s Relation-Based Properties
1. Consider $$X$$,$$Y\in\mathbb{R}^{n\times m}$$ and $$Z\in\mathbb{S}^m$$. The matrix inequality given by

 * $$\begin{align}

Z + XTY + YTX>0, \end{align}$$

 * is satisfied if and only if there exist $$Q\in \mathbb{S}^m$$, $$P\in\mathbb{S}^n$$,$$ G1\in\mathbb{R}^{n\times n}$$,$$

G2\in\mathbb{R}^{n\times m}$$,$$ F\in\mathbb{R}^{m\times n}$$, and $$H\in \mathbb{R}^{m\times m}$$, where $$Q > 0$$

 * and $$P > 0$$, such that

\begin{bmatrix}P&Y\\*&Q\end{bmatrix}>0 $$ and $$\begin{bmatrix}Z+Q+X^TPX & F-X^TG_2&H-X^TG_1\\*&G_1+G_1^T-P&F^T+G_2-Y\\*&*&H^T+H-Q\end{bmatrix} $$ 2. Consider $$X$$,$$Y\in\mathbb{R}^{n\times n}$$ and $$W\in\mathbb{S}^m$$, where $$X$$ is full rank and $$W>0$$. The matrix inequality given by

 * $$\begin{align}

X^T-W>0, \end{align}$$

 * is satisfied if there exist $$\lambda\in \mathbb{R}_{>0}$$ such that

\begin{bmatrix}\lambda\mathbf{1}&\lambda\mathbf{1}&\mathbf{0}\\*&\mathbf{X}+\mathbf{X}^T&\mathbf{W}^{\frac{1}{2}}\\*&*&\lambda\mathbf{1}\end{bmatrix}>0 $$


text:
User:Shnizzedy/sandbox/Glossary/example term

this is a chapter 1


text:
User:Shnizzedy/sandbox/Template:Define

Definitions can be found in either  or in a labeled section (like  ) in

If both exist, the definition on a standalone page will be the one used.

standalone definition page
with definition at User:Shnizzedy/sandbox/Glossary:example_term generates

labeled definition section
with definition at User:Shnizzedy/sandbox/Glossary generates

another book
with definition at CACS/Glossary/Computer generates

{	"params": { "term": { "description": "The term to define", "example": "peak height", "type": "string", "required": true },		"print-as": { "description": "How to display the term on the page", "type": "string" },		"book": { "description": "The title of the Wikibook containing the definition", "example": "Neuroimaging_Data_Processing", "type": "wiki-page-name", "default": "the current " },		"namespace": { "description": "The namespace containing the definition", "type": "string", "default": "the current " }	},	"description": "Hovertext for a definition for a given term in a given book. Requires a definition to exist in :." }

title: User:Shnizzedy/sandbox/Template:Define


text: User:Shnizzedy/sandbox/

title: User:Shnizzedy/sandbox/


text:
User:Shnizzedy/sandbox/Glossary:example term

example definition


text:
User:Shnizzedy/sandbox/Template/Define

Preview: /

title: User:Shnizzedy/sandbox/Template/Define


text:
User:SwooshEdits

Hi guys, girls, and everyone else! My name is Isaiah, but everyone calls me Swoosh! I am a sexual health counselor/researcher, and came to WikiBooks to share my discoveries, and help discover more information on your topics. If anyone would like non-judgmental information about sexual health or other related topics or would like to just vent (anonymity encouraged and supported), contact me through my discussion page and we can talk from there. I am only here to help!

title: User:SwooshEdits


text:
The Computer Revolution/Security

Security

 * Attacks
 * Defenses
 * Cyber Villains
 * Passwords
 * Biometrics
 * Computer Crime
 * Encryption
 * Firewall
 * Prevent Identity Theft
 * Dirty Data
 * Cyber Threats
 * Cyber Bullying
 * The Evil Twin Attack
 * Malware
 * Technology Misuse
 * Privacy Threatened
 * The Fair and Accurate Credit Transactions Act
 * Properly Dispose of Hardware Containing Data
 * Surveillance Systems
 * Employee Monitoring
 * Digital Counterfeiting
 * What Is Phishing
 * Presence Technology

title: The Computer Revolution/Security


text:
User:Ade56facc

Interests

 * technology
 * languages
 * ancient history

title: User:Ade56facc


text:
Talk:Public International Law/Human Rights Law/Human Rights Protection/Asian Human Rights System

Review: 12 June 2023
Dear Mando,

Same here - thanks for the very interesting chapter! See my few and minor comments in the text.

Best, Raffaela

--Raffaela Kunz (discuss • contribs) 16:14, 12 June 2023 (UTC)

Review: 7 June 2023
Dear Mando,

I had very little to add to the many existing comments and would also like to encourage you to consider them and revise the chapter accordingly. Thank you again for being such a productive team member!

Warmly

Sué

Sué González Hauck (discuss • contribs) 14:57, 7 June 2023 (UTC)

Review: Max 26, 2023
Your systematic approach to introducing the Asian human rights "system" is commendable. You have meticulously covered the key components, including the legal frameworks, regional mechanisms, and notable bodies/institutions. By providing a comprehensive overview, you have created a valuable resource that allows students to gain a solid understanding of this unique Asian human rights system. Your chapter fills a crucial gap in the textbook literature.

I encourage you to carefully consider the older comments and incorporate them into your revisions to enhance the chapter's quality. You will also find new comments in your chapter in which I elaborate on something more specific. To view these comments, open your chapter page and click "Edit" in the top-right menu bar.

Some minor things:
 * You could add some links to other chapters of the textbook.
 * Note that I have made some linguistic improvements to the text

--Max Milas (discuss • contribs) 09:09, 26 May 2023 (UTC)

Review December 2021
Hi Mando,

I enjoyed reading this chapter and I think it communicates the main points very clearly.

I have no specific expertise on Asian human rights so just three mini-comments. I wouldn't consider any of them in any way necessary, just pick and choose whether or what you think makes sense:

- Having worked on regional diversity in other contexts I wonder whether the first paragraph, while rightly emphasising the fallacy of thinking of "Asia" as a homogenous region, doesn't over-emphasise the particularity of its diversity compared to other regions. Perhaps it might be worth questioning the notions of sameness and difference (with regard to what, according to whom, etc.) a bit more, if only in a half-sentence. But obviously depends on what you think of it and isn't a major point for the chapter as a whole, in any case.

- Perhaps add references to the sentence on colonialism and its enduring influence in the second paragraph? Since it's an aspect that is often overlooked in mainstream debates I feel like it helps students who are interested to find further readings on the topic which may otherwise not be self-evident.

- In Section C.II., unless I'm overlooking something, you don't state explicitly at the outset that the Declaration is legally non-binding. It might make sense to add a half-sentence here so that students don't have to read back and figure it out themselves once they reach the second paragraph of the section where it is presupposed.

Cheers, Jens Theilen (discuss • contribs) 13:41, 2 December 2021 (UTC)

 * Thank you, Jens! I clarified some of the points you raise and made a few other revisions.
 * Regarding references to colonialism my plan is to anchor back to the chapters of the book that will discuss this. This is why I don't add anything further here.
 * Happy New Year!
 * Mando Mando Rachovitsa (discuss • contribs) 06:01, 3 January 2022 (UTC)

Review: 24/05/2022
Dear Mando,

I really enjoyed reading your chapter. You found a very good balance between staying in the word limit, but still informative description of the Asian human rights "system"! I have put some comments in the text, which you can see by clicking on the edit mode. But these concern only minor things (sources, doctrinal clarifications, historical background information). I still see some need for revision in the two parts on the specifics of Asian approaches to IHRL and values. Both parts could be a bit more concrete. Nevertheless, this is already a great chapter Mando!

All the best

--Max Milas (discuss • contribs) 16:08, 24 May 2022 (UTC)


text:
Themes in Literature/For Readers

 In loving memory of Veronica A. Cover • For Contributors • For Readers • Volume I: Isolation and Community • Volume II: Love and Death • Volume III: Xenophobia and Xenophilia • Contributors • Print version

Dearest Themes in Literature Reader,

Our intention in creating this book is to allow you to spend a few hours reading or watching or listening to some wonderful literary pieces, learning about their authors, and perhaps spending some time pondering on the questions that their works bring up to mind.

We would love it if you left your impressions--even criticism!--on the discussion page for each entry. Or maybe you want to answer one or two of the discussion questions there. We'll leave that decision to you.

Wishing you much enjoyment,

 * Dr. X for the Themes in Literature collaborators.

 * December 2, 2021

title: Themes in Literature/For Readers


text:
Cookbook:Snickerdoodles (Boston Globe)

| Cookies

This snickerdoodle recipe is originally from the Boston Globe, June 14, 1898, pg. 8. Attributed to M. Elizabeth Adams.

Ingredients

 * ¾ cup butter
 * 2 cups white granulated sugar
 * 1 cup milk
 * 3 cups flour
 * 2 eggs
 * 2 tsp cream of tartar
 * 1 tsp baking soda
 * Sugar
 * Ground cinnamon

Procedure

 * 1) Cream the butter and sugar together.
 * 2) Beat in the eggs.
 * 3) Combine the flour, cream of tartar, and baking soda.
 * 4) Alternately mix the flour and milk into the batter to make a dough.
 * 5) Drop dough on a greased or lined baking sheet in spoonfuls.
 * 6) Sprinkle with sugar and cinnamon.
 * 7) Bake in a quick oven.

title: Cookbook:Snickerdoodles (Boston Globe)


text:
User:Shnizzedy/sandbox/Glossary

example
This is an example

title: User:Shnizzedy/sandbox/Glossary


text:
Cookbook:Snickerdoodles (Idaho Daily Statesman)

This recipe is from the Idaho Daily Statesman (Boise, Idaho), October 20, 1901, pg. 11. Per the source:"'Snickerdoodles' is the somewhat fantastic name of quickly made little cakes especially dear to the children's heart. A recipe for them copied from an old scrapbook [follows]."

Ingredients

 * 2 cups white granulated sugar
 * ½ cup butter
 * 2 eggs
 * 1 cup milk
 * 1 tsp baking soda
 * 2½ cups flour
 * 2 tsp cream of tartar
 * ½ tsp salt
 * Cinnamon
 * Sugar

Procedure

 * 1) Stir together sugar and butter until creamy.
 * 2) Add eggs.
 * 3) Dissolve baking soda in milk, then add.
 * 4) Add flour, cream of tartar and salt.
 * 5) Beat the batter thoroughly.
 * 6) Pour in shallow pans.
 * 7) Dust the top of the cake with cinnamon and sugar.
 * 8) Bake for 15 minutes.
 * 9) Cool, then cut in squares.


text:
User:EvanProdromou/vector.css

 * 1) cookbook-namespace-editnotice{display:none;}

title: User:EvanProdromou/vector.css


text:
Cookbook:Snickerdoodles I

One recipe for the production of snickerdoodle cookies is as follows.

Ingredients

 * 344 g (2 ¾ cups or 24 oz) all-purpose flour
 * ¼ tsp salt
 * 1 tsp baking soda
 * 2 tsp cream of tartar
 * 300 g (1 ½ cups or 12 oz) white sugar
 * 205 g (1 cup or 8 oz) soft shortening
 * 2 eggs, beaten
 * Cinnamon

Procedure

 * 1) Preheat oven to 205°C (400°F or Gas Mark 6).
 * 2) Combine the flour, salt, baking soda, and cream of tartar.
 * 3) Cream together the sugar and shortening. Beat in the eggs.
 * 4) Mix the flour mixture into the batter to make a dough.
 * 5) Shape dough into little balls, then transfer to a greased or parchment-lined lined baking sheet.
 * 6) Bake for 10 minutes or until crisp and light brown.
 * 7) Sprinkle generously with cinnamon while hot.

title: Cookbook:Snickerdoodles I


text:
Cookbook:Snickerdoodles II

One recipe for the production of snickerdoodle cookies is as follows.

Ingredients

 * 344 g (2 ¾ cups or 24 oz) all-purpose flour
 * ¼ tsp salt
 * 1 tsp baking soda
 * 2 tsp cream of tartar
 * 200 g (1 cups or 6 oz) white sugar
 * 100 g (½ cup or 4 oz) soft shortening
 * 110 g (½ cup or 4 oz) butter
 * 2 eggs, beaten
 * 2 tbsp sugar
 * 1 tsp cinnamon

Procedure

 * 1) Preheat oven to 205°C (400°F or Gas Mark 6).
 * 2) Mix flour, salt, baking soda, cream of tartar, sugar, shortening, and butter.
 * 3) Roll into 1 tbsp balls.
 * 4) Mix sugar and cinnamon.
 * 5) Roll balls in sugar-cinnamon mixture.
 * 6) Bake for 10 minutes or until crisp and light brown.
 * 7) Sprinkle generously with cinnamon while hot.

Notes, tips, variations

 * Other recipes add honey to the dough, which helps to keep the cookies from becoming too crisp.

title: Cookbook:Snickerdoodles II


text:
LMIs in Control/Controller Synthesis/Continuous Time/Optimal Dynamic Output Feedback/H-infinity

Discrete-Time H∞-Optimal Dynamic Output Feedback Control

In this section, a Dynamic Output feedback controller is designed for a Continuous Time system, to minimize the H∞ norm of the closed loop system with exogenous input $$w_{k}$$ and performance output $$z_{k}$$.

The System
Continuous-Time LTI System with state space realization $$(A,B,C,D)$$

\begin{align} \dot{x}&=Ax + B_1w + B_2u\\ z&=C_1x + D_{11}w+ D_{12}u\\ y &=C_2x + D_{21}w+ D_{22}u\\ \end{align}$$

The Data
The matrices: System $$ (A,B_{1},B_{2},C_{1},C_{2},D_{11},D_{12},D_{21},D_{22}), X_1,Y_1,Z, ,X_2,Y_2 $$

Controller $$ (A_{c},B_{c},C_{c},D_{c}) $$

The Optimization Problem
The following feasibility problem should be optimized:

$$ \gamma $$ is minimized while obeying the LMI constraints.

The LMI:
Solve for $$A_{n} \in {R^{n_x*n_x}}, B_{n} \in {R^{n_x*n_y}}, C_{n} \in {R^{n_u*n_x}}, D_{n} \in {R^{n_u*n_y}}, X_{1}, Y_{1}\in {S^{n_x}}, and \gamma \in {R_{>0}};$$ that minimize $$\mathcal{J}(\gamma) = \gamma$$ subject to $$X_1>0,Y_1>0,$$ $$\begin{align}

\\ \begin{bmatrix}N_{11} &A+A_n^T+B_2D_nC_2 &B_1+B_2D_nD_{21} &Y_1^TC_1^T+C_n^TD_{12}^T \\
 * &X_1A+A^TX_1+B_nC_2+C_2^T+B_n^T &X_1B_1+B_nD_{21} &C_1^T+C_2^TD_n^TD_{12}^T \\
 * & * &-\gamma \mathbf{1} &D_{11}^T+D_{21}^TD_n^TD{12}^T \\
 * & * &* &-\gamma \mathbf{1}\end{bmatrix}&>0,\\

\begin{bmatrix}X_{1} & \mathbf{1}\\
 * & Y_{1}\end{bmatrix}&>0,\\

\end{align}$$

where $$N_{11}=AY_1+Y_1A^T+B_2C_n+C_n^TB_2^T.$$ The controller is recovered by

$$ \begin{align} &A_{c} = A_{k}-B_{c}(1-D_{22}D_{c})^{-1}D_{22}C_{c}\\ &B_{c} = B_{k}(1-D_{c}D_{22})\\ &C_{c} = (1-D_{c}D_{22})C_{k}\\ &D_{c} = 1+D_{k}D_{22})^{-1}D_{k}\\ \end{align}$$

where, $$ \begin{align} \begin{bmatrix}A_{k} & B_{k}\\ C_{k} & D_{k}\end{bmatrix}&= \begin{bmatrix}X_{2} & X_{1}B_{d2}\\ 0 & 1\end{bmatrix}^{-1} (\begin{bmatrix}A_{n} & B_{n}\\ C_{n} & D_{n}\end{bmatrix} -\begin{bmatrix}X_{1}AY_{1} & 0\\ 0 & 0\end{bmatrix}) \begin{bmatrix}Y_{2}^T & 0\\ C_{2}Y_{1} & 1\end{bmatrix}^{-1}

\end{align}$$ and the matrices $$X_2$$ and $$Y_2$$ satisfy $$X_2Y_2^T = 1 - X_{1}Y_{1}$$. If $$D_{22}=0$$, then $$A_c=A_k,B_c=B_k,C_c=C_k,$$ and $$D_c=D_k$$.

Given $$X_1$$ and $$Y_1$$, the matrices $$X_2$$ and $$Y_2$$ can be found using a matrix decomposition, such as a LU decomposition or a Cholesky decomposition.

Conclusion:
The Continuous-Time H∞-Optimal Dynamic Output Feedback Controller is the system $$ (A_{dc},B_{dc},C_{dc},D_{dc}) $$

Implementation
The LMI given above can be implemented and solved using a tool such as YALMIP, along with an LMI solver such as MOSEK.

Related LMIs
Discrete Time H∞ Optimal Dynamic Output Feedback Control

Continuous Time H2 Optimal Dynamic Feedback Control


text:
LMIs in Control/Controller Synthesis/Continuous Time/Optimal Dynamic Output Feedback/H-2

Discrete-Time H2-Optimal Dynamic Output Feedback Control

A Dynamic Output feedback controller is designed for a Continuous Time system, to minimize the H2 norm of the closed loop system with exogenous input $$w$$ and performance output $$z$$.

The System
Continuous-Time LTI System with state space realization $$(A,B,C,D)$$

\begin{align} \dot{x}&=A_x + B_{1}w + B_{2}u\\ z&=C_{1}x + D_{11}w_k+ D_{12}u\\ y&=C_{2}x + D_{21}w+ D_{22}u\\ \end{align}$$

The Data
The matrices: System $$ (A,B_{1},B_{2},C_{1},C_{1},D_{11},D_{12},D_{21},D_{22}), X_1,Y_1,Z, ,X_2,Y_2 $$

Controller $$ (A_{c},B_{c},C_{c},D_{c}) $$

The Optimization Problem
The following feasibility problem should be optimized:

$$ \nu $$ is minimized while obeying the LMI constraints.

The LMI:
Solve for $$A_{n} \in {R^{n_x \times n_x}}, B_{n} \in {R^{n_x \times n_y}}, C_{n} \in {R^{n_u \times n_x}}, D_{n} \in {R^{n_u \times n_y}},X_{1}, Y_{1}\in {S^{n_x}}, Z \in {S^{n_z}},$$ and $$\nu \in {R_{>0}}$$ that minimize $$\mathcal{J}(\nu)<\nu$$ subject to $$X_{1}>0, Y_{1}>0,Z>0,$$

\begin{align}

\begin{bmatrix} AY_1+Y_1A^T+B_2C_n+C_n^TB_2^T &A+A_n^T+B_2D_nC_2 &B_1+B_2D_nD_{21}\\
 * &X_1A+A^TX_1+B_nC_2+C_2^TB_n^T &X_1B_1+B_nD_{21}\\
 * & * &-\mathbf{1}\end{bmatrix}&>0,\\

\begin{bmatrix} X_1 &\mathbf{1} &Y_1C_1^T+C_n^TD_{12}^T\\
 * &Y_1 &C_1^T+C_2^TD_n^TD_{12}^T \\
 * & * &Z \end{bmatrix}&>0,\\

D_{11}+D_{12}D_{n}D_{21}=0\\

\begin{bmatrix}X_{1} & \mathbf{1}\\
 * & Y_{1}\end{bmatrix}&>0,\\

trZ<\nu \end{align}$$

The controller is recovered by

$$ \begin{align} &A_{c} = A_{k}-B_{c}(1-D_{22}D_{c})^{-1}D_{22}C_{c}\\ &B_{c} = B_{k}(1-D_{c}D_{22})\\ &C_{c} = (1-D_{c}D_{22})C_{k}\\ &D_{c} = (1+D_{k}D_{22})^{-1}D_{k}\\ \end{align}$$

where, $$ \begin{align} \begin{bmatrix}A_{k} & B_{k}\\ C_{k} & D_{k}\end{bmatrix}&= \begin{bmatrix}X_{2} & X_{1}B_{2}\\ \mathbf{0} & 1\end{bmatrix}^{-1} (\begin{bmatrix}A_{n} & B_{n}\\ C_{n} & D_{n}\end{bmatrix} -\begin{bmatrix}X_{1}AY_{1} & \mathbf{0}\\ \mathbf{0} & \mathbf{0}\end{bmatrix}) \begin{bmatrix}Y_{2}^T & \mathbf{0}\\ CY_{1} & \mathbf{1}\end{bmatrix}^{-1}

\end{align}$$ and the matrices $$X_2$$ and $$Y_2$$ satisfy $$X_2Y_2^T = 1 - X_{1}Y_{1}$$. If $$D_{22}=0,$$ then $$A_c=A_k,B_c=B_k,C_c=C_k$$ and $$D_c=D_k.$$

Given $$X_1$$ and $$Y_1$$, the matrices $$X_2$$ and $$Y_2$$ can be found using a matrix decomposition, such as a LU decomposition or a Cholesky decomposition.

If $$D_{11} = 0$$, $$D_{12} \neq 0,$$ and $$D_{21} \neq 0$$, then it is often simplest to choose $$D_{n} = 0$$ in order to satisfy the equality constraint

Conclusion:
The Continuous-Time H2-Optimal Dynamic Output feedback controller is the system $$ (A_{c},B_{c},C_{c},D_{c}) $$

Implementation
The LMI given above can be implemented and solved using a tool such as YALMIP, along with an LMI solver such as MOSEK.

Related LMIs
Discrete Time H2 Optimal Dynamic Output Feedback Control

Continuous Time H∞ Optimal Dynamic Output Feedback Control


text:
Neuroimaging Data Processing/Glossary

BOLD
blood-oxygen-level-dependent

EPI
(gradient-echo) echoplanar imaging

fMRI
functional magnetic resonance imaging

MRI
magnetic resonance imaging

rotation
turning the entire image around an axis in space: x-y, x-z, y-z (in the absence of translation)

TE
echo time

TR
repetition time

translation
moving the entire image volume along an axis in space: x-,y-, and z-axes (in the absence of rotation)

volume
one 3-dimensional image, i.e., one timepoint in a 4-dimensional fMRI image

voxel
one 3-dimensional unit (length × width × height) in a 3-dimensional image (analogous to a pixel in a 2-dimensional image)

title: Neuroimaging Data Processing/Glossary


text:
User:Shnizzedy/sandbox

This section introduces the different formats used for undefined datasets and how to convert them into each other. Normally, undefined image data are stored in a binary data file as either 8- or 16-bit integers. Besides the raw image data, there is usually a metadata along with to provide the descriptive information about the subject, type of image, imaging parameters as well as image dimensions. In the history of neuroimaging there have been several different image formats playing important roles. In the following sections, three major kinds of formats are going to be discussed in detail.

title: User:Shnizzedy/sandbox


text:
Neuroimaging Data Processing/Processing/Steps

This is a collection of possible preprocessing steps. Which steps you include and also their order depends on your research question and to an extent also on the software you use


text:
LMIs in Control/Matrix and LMI Properties and Tools/Continuous Time/Schur Complement

 * Schur Complement
 * /Strict Schur Complement/
 * /Nonstrict Schur Complement/


text:
LMIs in Control/Matrix and LMI Properties and Tools/Continuous Time/Schur Complement/Strict Schur Complement

Strict Schur Complement
Consider $$A \in \mathbb{S}^n, B \in \mathbb{R}^{n \times m},$$ and $$C \in \mathbb{S}^m.$$ The following statements are equivalent.

a) $$\begin{bmatrix}A &B\\ B^T& C \end{bmatrix}< 0$$

b) $$A-BC^{-1}B^T<0,C<0$$

c) $$C-B^TA^{-1}B<0,A<0$$


text:
Cookbook:Snickerdoodles III

| Cookies

Snickerdoodles made from this recipe are chewy the same day you make them and become crunchy the next day.

Dough

 * 227 g (2 cups or 16 oz) butter, softened (not melted)
 * 100 g (1 cup) white granulated sugar
 * 2 tbsp baking soda
 * ¼ tsp cream of tartar
 * 1 egg
 * 220 ml (1 cup or 8 fl oz) vinegar
 * ½ tsp vanilla
 * 188 g (1 ½ cups or 12 oz) all-purpose flour

Topping

 * 2 tbsp (30 g) sugar
 * 1 tsp ground cinnamon

Procedure

 * 1) Preheat oven to 375°F (190°C or Gas Mark 5)
 * 2) In a medium mixing bowl, beat butter with an electric mixer on medium to high speed for 30 seconds.
 * 3) Add the 1 cup sugar, baking soda, cream of tartar, and vinegar. Beat until combined, scraping sides of bowl occasionally.
 * 4) Beat in egg and vanilla until combined.
 * 5) Beat in as much of the flour as you can with the mixer. Stir in any remaining flour.
 * 6) Cover and chill dough for 1–2 hours or until easy to handle.
 * 7) Combine the 2 tbsp sugar and the cinnamon in a small bowl.
 * 8) Shape dough into 1-inch (2.5 cm) balls. Roll balls in cinnamon-sugar to coat. Place balls 2 inches (5 cm) apart on an ungreased cookie sheet.
 * 9) Bake for 10–11 minutes or until edges are golden. Transfer to a wire rack and let cool.

Notes, tips, and variations

 * If you are using a mixer with more than one kind of beater, use the paddle attachment.

title: Cookbook:Snickerdoodles III


text:
User:EvanProdromou

I've been kitchen-testing recipes from the Cookbook and updating them if needed.

title: User:EvanProdromou


text:
LMIs in Control/Matrix and LMI Properties and Tools/Continuous Time/Schur Complement/Nonstrict Schur Complement

Nonstrict Schur Complement
Consider $$A \in \mathbb{S}^n, B \in \mathbb{R}^{n \times m},$$ and $$C \in \mathbb{S}^m.$$ The following statements are equivalent.

a) $$\begin{bmatrix}A &B\\ B^T& C \end{bmatrix} \leq 0$$

b) $$A-BC^{+}B^T <0,C \leq 0, B(\mathbf{1}-CC^+)=\mathbf{0},$$ where $$C^+$$ is the Moore-Penrose inverse of $$C.$$

c) $$C-B^TA^{+}B<0,A \leq 0,B^T(\mathbf{1}-AA^+)=\mathbf{0}$$ where $$A^+$$ is the Moore-Penrose inverse of $$A.$$


text:
Talk:Hebrew/Discussion

How do you say please

title: Talk:Hebrew/Discussion


text:
Lentis/The Legacy of the Donora Smog of 1946

Introduction
First Established in 1901, Donora is a town in Pennsylvania approximately 20 miles south of Pittsburgh. Around that same time the first steel mill operated by the Union Steel Company was constructed. By the year 1948 this mill, as well as another constructed near it, would be owned by the American Steel and Wire Company. Having brought many jobs to the Donora area, the population of the town grew to approximately 14,000 by 1948. It was that same year in which an environmental disaster took place over Donora. Having lasted 5 days in October from the 26th - 31st, heavy amounts of air pollutants like carbon-monoxide and heavy metal particles resided above Donora. This event resulted in the deaths of 20 individuals and caused lasting health effects for many more. As a result of this incident, legislation such as the Air Pollution Control Act of 1955 and the Clean Air Act of 1963 were passed in order to prevent such a disaster from reoccurring in America.

Main Contributor
The bulk of the air pollution came from steel mills owned by American Steel and Wire Company. Originally the steel mill was constructed in 1900 and was acquired by American Steel from Carnegie Steel in 1908. With WWI starting in 1914, the demand for steel rods and wires grew dramatically. To help meet this demand a secondary mill, Donora Zinc Works, was constructed in 1915 by American Steel. The main purpose for this mill was to smelt zinc ingots which would be shipped to other steel mill to be used as a protective coating for steel products.

On October 29th, 1915, the first zinc ingot was smelted at Donora Zinc Works. The methods in which they smelted Zinc created several by-products such as cadmium, lead, and sulfuric-acid. Because of this, large amounts of heavy metal particles would be thrown into air and remain in the soil. Additionally, toxic gasses such as carbon-monoxide and sulfur-dioxide filled the air of the nearby town. During the smog disaster of 1948, its estimated that amount of sulfur-dioxide in the air reached as high as 5,500 μg/m3. This heavy pollution caused 17 of the 20 deaths within twelve hours, and resulted in several thousand other cases of respiratory problems.

Weather Effects and Contributing Factors
While the smog over Donora existed prior to October 26th, the disaster lasted for five days for specific reasons. On the date of October 26th a cold front moved in over Donora. With little to no wind and warmer air remaining stagnant above this cold front, an event called a Temperature Inversion took place. This trapped much of the pollution at a low altitude and was blocked in by the hills surrounding Donora. The combination of the inversion and the geography surrounding the town is what caused the disaster to last five days. With high amounts of smoke residing at nearly ground level, the visibility for first responders and other pedestrians was extremely poor. This made reaching citizens in need increasingly difficult towards the end of the event.

Donora's Reaction and Aftermath
As the mill grew so did the town, and by 1948 nearly half of Donora, 6,500 people, worked for American Steel at one of the mills. This made it hard to speak out against Donora Zinc Works as many residents depended on the mills financially. Additionally, six of the seven members of the Donora council were employed by American Steel, and they feared job losses if the mill was regulated. It wasn't until the 20th resident died that the mills halted production of steel and zinc ingots on Sunday, October 31st. Accusations were immediately directed at Zinc Works for the use of reprocessed materials in the furnaces. Eventually, Zinc Works would close in 1957 while still denying any responsibility for the incident. Ten years later all American Steel mills would close down in 1968.

Acute Health Effects
During the multi-day smog event, 20 people died from causes related to the smog and an estimated 5000-7000 were cited as became very ill. Data collected in the study after the event showed that 43% of the population of Donora's health had been effected in some way. The most common symptom resulting from the poor air quality was dyspnea or difficulty breathing. Some of the pollutants found in the smog of Donora that contributed to the negative health effects on the population are listed below. Other pollutants researchers found were present included carbon monoxide and nitrogen dioxide.

Long Term (Chronic) Effects
The acute health effects experienced by the residents of Donora were not the end of the harm stemming from the event. A decade after the smog event, the mortality rate of Donora was higher than it had been before 1948 as well as higher than that seen in nearby areas. Many affected by the smog additionally developed detrimental symptoms such as cancers and cardiovascular disease. The cumulative mortality rate adjusted for age from the year 1948 to 1957 split by gender can be seen in Figure 1. In the survey conducted to obtain these data an acute illness was recorded if a person was affected immediately following the smog of 1948. From this plot we can see that the group who were affected displayed a higher mortality rate in the following eight years compared to those who had not been affected by the smog.

Resulting Environmental Regulations
The Donora Smog was one of the most pivotal events leading to the adoption of air quality regulations in the United States. Prior to the event, clear skies were considered an indicator of economic depression, whereas cloudy skies were a sign of prosperity. Another contributing factor towards federal legislation on air pollution was the Great London Smog of 1952. From December 5th to 9th, a combination of industrial pollution from coal-burning furnaces and a temperature inversion resulted in a deadly smog that claimer over 4,000 lives.

Air Pollution Control Act
Continued concern over events such as the Donora Smog and the Great London Smog led to the creation of the Air Pollution Control Act of 1955, which was the first federal legislation involving air pollution in the United States. This Act allocated federal funds towards research on the scope and sources of air pollution, and served as a national warning about the dangers of air pollution.

Clean Air Act
The Clean Air Act of 1963 was swiftlfy passed by Congress and signed into law by President Lyndon B. Johnson. It was the first federal legislation for air pollution control which established a federal program for monitoring and controlling air pollution.

The historic Earth Day of 1970 and growing public concern over environmental pollution, culminated in Congress passing a more stringent Clean Air Act. The Clean Air Act of 1970 established federal and state regulations to limit emissions from industrial and mobile sources. This included the National Ambient Air Quality Standards (NAAQS), State Implementation Plans (SIPs), New Source Performance Standards (NSPS), and National Emission Standards for Hazardous Air Pollutants (NESHAPs). NAAQS set limits for six principal pollutants- carbon monoxide, lead, nitrogen dioxide, ozone, particulate soot levels, and sulfur dioxide. In the same year, the Environmental Protection Agency (EPA) was established to regulate and implement these limits to prevent another incident like the Donora Smog from occurring again. For example, the Act set a limit of 80 micrograms per cubic meter on the amount of sulfur dioxide allowed in the air, whereas there was around 1,500 to 5,000 micrograms of sulfur dioxide per cubic meter in the air during the Donora incident.

Conclusion
The Donora Smog of 1948 was an important event in paving the way for enacting environmental regulations to control pollution. While the event was extremely detrimental to the health of the residents of Donora, in the long run its legacy helped prevent other cities in the United States from experiencing similar effects from air pollution. In this chapter we explored the contributing factors to the smog and the town's reaction, the acute and chronic health effects caused by the high levels of air pollution seen, and the resulting environmental regulations.

Next steps would include looking at places around the world where smog events are still occurring. For example, China and India contain 90 percent of the 200 cities with the worst air pollution, and over 1 million premature deaths every year in China are due to air pollution. It is important that we remember the lessons learnt in Donora about the dangers of air pollution and the need for regulations to limit emissions of air pollutants.


text:
User talk:2.86.197.193

replace cyrylic words to beat filter, nothing has been deleted, except wkstupidity has been shown:

арцхиве.мд/68Zjv

title: User talk:2.86.197.193


text:
LMIs in Control/Matrix and LMI Properties and Tools/Frobenius Norm

Frobenius Norm
Consider $$A\in \R^{n\times m} $$ and $$\gamma\in \R$$>0

The Frobenius norm of $$A $$ is $$||A|| $$F =$$\sqrt{tr(A^{T}A)}=\sqrt{tr(AA^{T})}$$

The Frobenius norm is less than or equal to $$\gamma$$ if and only if any of the following equivalent conditions are satisfied.

1.There exists $$S\in \R^{n} $$ such that
 * $$ \begin{bmatrix} Z & A^{T} \\

* & 1\\                           \end{bmatrix} \ge0,

$$

\begin{align} \qquad tr(Z)\le\gamma^{\text{2}}. \qquad   \\ \end{align}                              $$

2.There exists $$S\in \R^{m} $$ such that
 * $$ \begin{bmatrix} Z & A \\

* & 1\\                           \end{bmatrix} \ge0,

$$

\begin{align} \qquad tr(Z)\le\gamma^{\text{2}}. \qquad   \\ \end{align}                              $$


text:
User talk:Tbikila

Please stop creating standalone pages. This is disruptive. Pages should be named "your book/page" and not "page". Creating a sandbox with links to incorrectly named pages is likely to cause this to happen again. If it keeps happening you may be blocked and have your work deleted. QuiteUnusual (discuss • contribs) 08:39, 3 December 2021 (UTC)

title: User talk:Tbikila


text:
PostgreSQL/Wraparound and Freeze

Two Fundamental Problems

Transactions are identified by ids which are realized as unsigned 32-bit integers and named XID. Transactions and their XIDs are known at the cluster level, covering all databases. Similar to sequences, XIDs are incremented by $$+1$$ for every new transaction. Sooner or later, this limited space of $$2^{32}$$ numbers is exhausted, and it becomes necessary to restart the sequence from the beginning (the values 0, 1, and 2 are skipped because they are reserved for particular purposes). This restart of XIDs is called a wraparound and each cycle an epoch.

It's unlikely that more than $$2^{32}$$ transactions exist in a cluster at the same time or that a single transaction lasts for such a long time that its XID collides with the same value of the next cycle. At first glance, this cyclic usage of the '$$2^{32}$$ Universe' seems to be safe and easy to implement. Nevertheless, huge problems will arise with this simple strategy. The reason is that XIDs are stored in system columns within every row (see  in the MVCC chapter). And rows stay for a very long time in the database, in many cases forever.

XID Collision
The first problem is that after a wraparound, the next XIDs (3, 4, 5, ...) may collide with XIDs of the previous epoch. They are no longer unique because system columns of old rows may contain the same values. But transactions must be able to decide whether retrieved rows are modified (by other transactions) after their own start-time or a long time ago. We call this first problem XID Collision.

Sudden Death
The second problem correlates with MVCC and the timeline of transactions. Rows may exist in multiple versions. When a transaction modifies a row and stays alive a little longer - no COMMIT or ROLLBACK because of more activities -, other processes shall 'see' the version of the row as of the start-time of the transaction and not the uncommited modification. Hence, a mechanism must hide the ongoing changes and give other transactions the feeling of a stable data environment. The system realizes this by considering additional criteria with every SQL command, especially - but not only - the system column.

You can imagine of those additional criteria that the system silently supplements every query with the predicate. (This is only an illustration in pseudo-code, the real implementation is different.) It guarantees that changes happening after the start of the requesting transaction are invisible to it.

So far, so good.

But what will happen after a wraparound? The next transactions will have very small XIDs, e.g., '5'. And what will be the result of an ? Near nothing. All rows with  between $$5$$ and $$2^{32}-1$$ are no longer part of any query. In contrast to the situation a few moments ago, all data suddenly disappeared. It is still in the database, but it is unreachable. We call this second problem Sudden Death.

Solution
Step 1 : At the conceptual level, the full '$$2^{32}$$ Universe' is divided into two halves of $$2^{31}$$ numbers. One split point is the current transaction id  (it was called   before PostgreSQL version 13) and the other is the opposite side of the circle   (or   what is the same). So, the split points are not fixed values but follow dynamically the ongoing of new transactions. One halve represents the previously used and therefore exhausted XIDs; the other halve such XIDs, which are - per definition - free. They will be allocated in the future. Please note the dynamic aspect: with every new transaction in the cluster  and the border between 'past / future' moves forward. This is a metaphor of an endless walk through time where after some time the old problems will be forgotten or at least idealized.

The idea can be realized by a modification of the above  predicate to an   block:

if (my_xid < $$2^{31}$$) return rows with: xmin < my_xid OR xmin > my_xid + $$2^{31}$$ else return rows with: xmin < my_xid AND xmin > my_xid + $$2^{31}$$

Of course, this is a simplification and many other criteria like COMMIT status, 'is deleted', and other things must be considered. It focuses purely on the aspect of the 'past / future' metaphor.

Note: With this algorithm the 'critical point' changes from  resp. to. It is called the wraparound point and the line between  and   the wraparound horizon.

Step 2 : The outlined algorithm ensures the visibility of 50% of all possible XIDs. But what's going on with the others? As mentioned, rows may stay in the database forever holding very old XIDs in. This halve must also be considered. The idea of how to access the complete range of possible XIDs is to complement the previous algorithm with the introduction of a flag that marks certain rows as 'visible forever' (respectively visible until the next write operation to them). This marking is not possible as long as one or more transactions potentially get write access to them. Fortunately, the sequence of new XIDs goes strictly forward, and overtime transactions with old XIDs finish. PostgreSQL does not only know, which is the current XID, but also which is the oldest active XID per connection (pg_stat_activity.backend_xmin), and which is the lower bound of all unfrozen XIDs per table (pg_class.relfrozenxid) and per database (pg_database.datfrozenxid). Rows with  older than   are candidates for such a flag. No running transaction has or will get write access to them, only newer ones. According to MVCC, they will create a new row version, this one keeps as it is.

It is one of the two main duties of VACUUM to perform this freezing. It marks the identified rows with a flag in their header  as 'visible forever'. From this point on no comparisons with  take place. The rows are always treated as visible, even if they are part of the 'future'. This marking is called FREEZE and the status of the row FROZEN.

Now the algorithm for retrieving rows changes to:

-- 'frozen' rows will always be returned if (my_xid < $$2^{31}$$) return rows with: frozen OR                     (xmin < my_xid OR  xmin > my_xid + $$2^{31}$$) else return rows with: frozen OR                    (xmin < my_xid AND xmin > my_xid + $$2^{31}$$)

With this extension, the two mentioned problems are solved. The system can generate XIDs even after a wraparound without risk of collision with old XIDs. The old ones may exist, but they are not touched in any way. Second, the algorithm finds all relevant XIDs whether there was a wraparound or not.

Wraparound Failure
It is possible that a transaction - intentionally or by an error in an application - stays alive for a long time. Over time its XID becomes the oldest one in the complete cluster and can be retrieved from pg_stat_activity.backend_xmin. As long as this situation continues, the gap between the ongoing wrapping point  and pg_stat_activity.backend_xmin gets smaller and smaller. If the gap would close completely, we would see all the problems described at the beginning of the chapter. This is called wraparound failure and must be avoided under all circumstances. VACUUM is doing its best to freeze as many rows as possible. But if a long-living transaction prevents freezing and the size of the gap falls below a certain limit, VACUUM runs in an 'aggressive mode' and works on all pages of affected tables, independent from the above-mentioned values; if also this fails, the cluster stops the creation of new transactions and prevents further write actions.

Details
Note: These details can be skipped by a novice reader without losing the context of the ongoing chapters.

To freeze any row version, VACUUM must check several criteria:
 * must be zero because only non-deleted rows can be visible forever.
 * must be older than all currently existing transactions . This guarantees that no existing transaction can modify or delete the version.
 * The transactions of  and   must be committed.

At what point in time does the freeze operation take place? Please note that there are configuration parameters with names like. They define distances - mostly to  -, where the actions of VACUUM shall start. 'age' in this context doesn't imply a certain period of time, it's always a pure number that counts transactions, e.g., 50 million. Please also note, that VACUUM always reads complete physical pages and works on the row versions found there.

 * When a client issues the SQL command VACUUM with its FREEZE option. In this case, all pages of the affected tables are processed that are marked in the Visibility Map as potentially having unfrozen rows.
 * When a client issues the SQL command VACUUM without any option and there are XIDs older than vacuum_freeze_table_age (default: 150 million) minus vacuum_freeze_min_age (default: 50 million). As before, all pages are processed that are marked in the Visibility Map to potentially have unfrozen rows.
 * When an Autovacuum process runs. Such a process acts in one of two modes: In the normal mode it skips pages with row versions that are younger than vacuum_freeze_min_age (default: 50 million) and works only on pages where all XIDs are older. The skipping of young XIDs prevents work on such pages, which are likely to be changed by one of the future SQL commands. The process switches to an aggressive mode if it recognizes that for the processed table the oldest XID exceeds vacuum_freeze_table_age (default: 150 million). In this aggressive mode, Autovacuum processes all pages of the affected table.

VACUUM and Autovacuum know to which value the oldest unfrozen XID has moved forward per table and logs the value in pg_class.relfrozenxid. The distance between this value and the  split point becomes smaller (there are potentially unfrozen rows), and the distance to the wraparound point   becomes larger (there are only frozen rows). That is how the freezing follows the moving 'past' / 'future' horizon.

Note: Before version 9.4 of PostgreSQL, the freeze algorithm stored the value '2' (FrozenTransactionId) in  instead of setting a flag in.

title: PostgreSQL/Wraparound and Freeze


text:
Neuroimaging Data Processing/References

 * AFNI program: 3dDespike: Output of
 * AFNI program: 3dTcat: Output of
 * AFNI program: 3dToutcount: Output of
 * Huettel, S. A., Song, A. W., & McCarthy, G. (2008). Functional Magnetic Resonance Imaging (2nd ed.). Sinauer Associates, Inc: Sunderland, Massachusetts, USA.
 * Siemens Healthineers. Magnets, Spins, and Resonances: An introduction to the basics of Magnetic Resonance. https://www.magnetomworld.siemens-healthineers.com/publications/mr-basics#text-media-9000000a02841180
 * Poldrack, R. A., Mumford, J. A. Nichols, T. E. (2011). Handbook of functional MRI data analysis. New York: Cambridge University Press
 * practiCal fMRI: the nuts & bolts. http://practicalfmri.blogspot.de/

title: Neuroimaging Data Processing/References


text: Neuroimaging Data Processing/Data

title: Neuroimaging Data Processing/Data


text:
Neuroimaging Data Processing/Data/Storage/Filetypes

This section introduces the different formats used for undefined datasets and how to convert them into each other. Normally, undefined image data are stored in a undefined data file as either 8- or 16-bit integers. Besides the raw image data, there is usually a metadata along with to provide the descriptive information about the subject, type of image, imaging parameters as well as image dimensions. In the history of neuroimaging there have been several different image formats playing important roles. In the following sections, three major kinds of formats are going to be discussed in detail.
 * DICOM
 * NIfTI
 * AFNI
 * GIfTI


text:
Neuroimaging Data Processing/Data/Storage/Organization

There also exists a format for organizing and describing outputs and datasets of neuroimaging experiments called the Brain Imaging Data Structure (BIDS) format. The BIDS standard uses file formats compatible with existing software, unifies the majority of practices already common in the field, and captures the metadata necessary for most common data processing operations.

Certain preprocessing workflows, such as fMRIprep, will require the data to be in BIDS format.


text:
Neuroimaging Data Processing/Data/Storage

 * 1) Filetypes
 * 2) Organization


text: Neuroimaging Data Processing/Introduction


text: Neuroimaging Data Processing/Processing

title: Neuroimaging Data Processing/Processing


text:
Neuroimaging Data Processing/Introduction/Local Manual of Style

Navigation
At the top of each page, include a Navigate template within a  element. This will automatically include the page in Book:Neuroimaging Data Processing

If the page is within a chapter, put the book-slash-chapter title in. If there is a previous page at the same level of depth, put that page's title in. Put the current page's title in. If there is a next page at the same level of depth, put that page's title in.

For example, this page's template is filled out like:

When a new page is added or a page is moved, update the surrounding and containing pages to reflect the new structure.


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Neuroimaging Data Processing/Processing/Tools

This section regards the basic things needed to be known about the different softwares, like: where and how to get them, how is the general structure, what is special,... See the separate section of the actual processing steps for details on their implementation within the different softwares
 * SPM
 * FSL
 * AFNI


text: Neuroimaging Data Processing/Data/Quality


text:
Neuroimaging Data Processing/Processing/Steps/Despiking

Signal outliers e.g. due to excessive head movement can seriously affect the analysis. Motion correction algorithms are not build to deal with these. Therefore it makes sense to inspect your data before starting the actual preprocessing and get rid of signal outliers right away. You can plot voxel time series and check in different parts of the brain if they show huge peaks, but there are also automated methods to cover all voxels (see below). A good start is also to watch your volume in a fast movie-like sequence because big movements between two pictures will become apparent to you.

When outliers are detected, they should be dealt with. Removing whole volumes that show outliers would break the time series, thus complicating the analysis of signal time series and impairing Fourier transformation as used in later steps. Therefore, respective data points are rather interpolated from neighbouring data.

AFNI
3dToutcount calculates the number of outliers in each volume and writes the results into a file. Outliers are automatically defined as number of MAD (median absolute deviation) that are allowed, accounting for the number of TRs in the dataset. A typical limit is about 3.5*MAD distance to the trend. It makes sense to detrend the time series before looking for outliers. This can be done using the -polort nn option to detrend with polynomial of order nn (order is based on the duration of the first run: 1 + floor(duration/150 sec)) and the -legendre option to use legendre polynomials (allowing for polort > 3). For example: 3dToutcount -automask -fraction -polort 3 -legendre INPUTFILE > OUTCOUNTFILE.1D The outcountfile will thus contain the fraction of voxels per volume (within the automask) that exceed the outlier limits after 3rd degree legendre polynomial detrending. To check for excessive outliers you can use: 1deval -a OUTCOUNTFILE.1D -expr 't*step(a-0.03)' | grep -v '0' returning all timepoints with more than 3% outliers, or: 1dplot OUTCOUNTFILE.1D for visual inspection. In the example plot you see a considerable fraction of outliers in the 222th volume, which is also the one that has been found by the 1deval command. After using despike (see below), this outlier will be much reduced.

3dDespike actually removes spikes from the 3D+time input dataset and writes a new dataset with the spike values are replaced to fit a smooth curve. The spike cut values can be set via the option -cut c1 c2, where c1 is the threshold value of s for a 'spike' [default c1=2.5] and c2 is the upper range of the allowed deviation from the curve (s=[c1..infinity) is mapped to s'=[c1..c2) [default c2=4]). The order of the fit curve can be adjusted via -corder. Though 3dDespike can be run without visually checking for outliers, it is advisable to do so before and after despiking to keep track your data and detect possible oddities at the stage they first occur.

3dDespike [options] INPUTFILE

When running the outlier detection again on despiked data you can see if the outliers have been removed. For example the same plot as above but after despiking shows that the outlier has been reduced a lot (notice the difference y-range)

In afni_proc.py a despiking block can be included (but is not by default) -do_block despike

It is also possible to remove outliers in the regression, however, as far as I understand this will actually remove the respective volume and thus get you into the trouble mentioned above. Censoring TRs with more than n% outliers can be achieved by -regress_censor_outliers 0.0n


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Lentis/The Transformation of Times Square

Introduction
Established in 1904, Times Square has been a center within New York City for over a century. Around 360,000 people visit Times Square per day making it one of the largest pedestrian hubs of the city. The area has seen several periods of economic and artistic growth, as well as periods of decline, specifically from the 1940's-1990's due to increasing crime and the drug trade. The most important transformation occurred between 2012 and 2016 when sections of the streets were taken back for pedestrian use, creating a more vibrant, safe, and inviting space.

Historical Background
In the 1880's Long Acre Square, now Times Square, was just a large open courtyard home to the Vanderbilt's American Horse Exchange and surrounded by simple apartments. Due to electricity, the square began to transform into a bustling city center with several forms of public transportation flowing through it, including the Interborough Rapid Transit system. After its renaming by Mayor McClellan in 1904, the New York Times completed their headquarters building at the front of the plaza, which changed the surrounding area into a pedestrian center. The physical appearance of Times Square as well as societies perception of the space changed over the years as technology advanced, including the rise and fall of the trolley, and the bus and subway system we see today. The decline of the square began during the Great Depression which stunted further development. Theaters struggled to make money, so lower forms of entertainment such as burlesque shows and cheap restaurants took their places. When the trolley retired in 1957, Times Square became a car dominated space, pushing out pedestrians. In the 1960's, prostitution, drug trade, and alcoholism became rampant throughout the square and area around it. Times Square had the most felony and crime complaints recorded in the city by the late 70's. With the introduction of crack cocaine to Times Square in 1986, crime rates spiked and continued to rise into the 1990's. Although Times Square faced many hardships, it remained, and still remains, a symbol of New York City due to its "chaotic action, dense and diverse pedestrian, and continuous role as the key entertainment district".

1992-2012 Transformation
The unsafe and unenjoyable area that existed by the 1990's prompted the formation of the Times Square Alliance (TSA) (formally known as the Times Square Business Improvement District). This alliance was made up of city government and local businesses who were devoted to improving the quality of business and general experience for those in Times Square. Currently, their site emphasizes the preservation of the energy and creativity that have made Times Square into an "icon of entertainment, culture, and urban life for over a century". Over the first two decades of the TSA's existence, they implemented a variety of changes in order to create the long-lasting and pervasive perception alteration that has occurred. These changes focused on three main areas of improvement:

Clean
The first focus was placed upon the cleanliness of Times Square. To do so, the TSA partnered with Project Renewal to employ people recovering from substance-abuse in its street cleaning initiative. This was an effective way of cleaning the area while also offering job training and permanent employment of people who were looking for a new start. This partnership has acted as a model for other urban revitalization organizations throughout the country.

Safe
To address root causes of crimes occurring in the Times Square area, the TSA supported the Midtown Community Court in their efforts to rehabilitate those committing quality-of-life offenses. The TSA also commissioned a study to show that the large concentration of adult use businesses (not the sheer existence of them) was leading to increased illegal activity. The NYC Department of City Planning replicated this and used the results to pass a citywide rezoning to prohibit the concentration of these adult businesses in one area.

Homelessness was another problem that plagued Times Square. For the safety of this population as well as pedestrians, the TSA worked with the social service community and acquired a federal innovation grant to place the homeless into safe, permanent housing. The TSA also supported Breaking Ground, an organization that focuses on providing affordable and supportive housing resources.

Friendly & Experiential
The TSA wanted to focus on creating an engaging space for people to enjoy culture and art. In 1993, the TSA refurbished the Times Square Ball to provide an exciting event that was shared globally. The Broadway League worked with the TSA to organize the first Broadway on Broadway concert. This showed the world that Times Square was a safe space for theatergoers and their family members. The TSA developed a public art program, Times Square Arts to provide cutting-edge, modern art exhibitions in the area. In 2008, the TKTS booth was redesigned as the iconic red stairs for people to sit and enjoy Times Square.

Green Light for Midtown
Following an increase in traffic accidents in 2009, the TSA decided to redesign "the bowtie" intersection surrounding Times Square into a piazza that allowed for safer and easier foot traffic as part of their Green Light for Midtown Project. This three-phase project was completed with Snøhetta and the NYC Department of Transportation "to enhance mobility in West Midtown by simplifying intersections, removing conflicts and providing additional traffic and pedestrian capacity where needed." The project shut down 5 blocks of Broadway Street to vehicular traffic, which allowed for the addition of 110,000 square feet of pedestrian space, ten new 50-foot-long granite benches, and specific zones for pedestrian activity. These changes decreased pedestrian injuries by 40%, vehicular accidents by 15%, and overall crime by 20%.

Tactical Urbanism
The closing off of Broadway was primarily achieved through the use of tactical urbanism orchestrated by the Department of Transportation Commissioner Janette Sadik-Khan. Tactical Urbanism is the legal redesign of public spaces for aesthetic appeal, which can be used to motivate change and get community members more involved. In collaboration with the TSA, 376 plastic lawn chairs were placed on the closed off roads to provide pedestrians with a place to sit. The lawn chairs were initially marketed as temporary, but after positive feedback from the community the pedestrian plaza was made permanent. The lawn chairs were repurposed into an art installation by sculptor Jason Peters to make way for more permanent seating.

Backlash
Although the Green Light for Midtown Project is now seen as a huge success there was significant backlash at the time, specifically regarding the closing of a portion of Broadway to cars. Many cab drivers worried that it would not improve traffic conditions and would detract from their business. One cab driver interviewed for an article about the shutdown said, "I think it's really stupid. It's going to mess up all the traffic in midtown." There was also resistance from some New York City residents whole believed the chairs were an eyesore, cheap, and promoted laziness. Andrea Peyser, a writer for the New York Post, wrote a scathing review, stating "IN THE annals of stupid ideas, this has got to be the worst. Ever." Even though there was some very vocal opposition, the New York Department of Transformation found that 74% of New Yorkers surveyed as part of their Green Light for Midtown evaluation agreed that Times Square has improved dramatically.

Future Times Square
Due to the success of the 2012-2016 transformation in reinvigorating Times Square, the TSA is constantly looking to the future to update Times Square to meet the needs of New Yorkers and tourists. In recent years there has been a shift towards "entertainment retail" or "retailtainment", which is the concept of using retail spaces to entertain customers and create a memorable experience through engaging visuals, activities, and sounds. An example of this new change can be seen in the proposed TSX Broadway building, which is planned to be completed in 2022. This 46 floor building at the corner of 47th street and Broadway will combine experimental retail space, a built in stage on the exterior for performances, a renovated 105 year old historic theater, restaurants, integrated signage, and a hotel. The goal of this project is to reimage how real estate in Times Square can be used to create an engaging environment that celebrates Times Square's past while introducing new and exciting features that will increase use of the spaces provided.

“We are always reinventing and moving into our new reality”

- Tom Harris, acting president and COO of the Times Square Alliance.

Conclusions
Throughout the decades Times Square has undergone many physical changes that effected the use of the space and the way it was perceived by society. With the help of the city government, the space was cleaned and revitalized between 1992 and 2012 to make it safe again. This is a primary example of how government policy and action can effect the physical appearance of an area and therefore its perception by society. The square was further transformed between 2012 and 2016 to create a more welcoming space and gave access back to the pedestrians and visitors. Physical changes such as adding art exhibits and closing off roads allow pedestrians to feel more comfortable in the space and like they belong. It also allows the city to celebrate its diversity and creativity in a communal place where all can freely enjoy it. The transformation of Times Square is a critical example of the intersection between technology and how it effects social attitudes. Physical changes to the city center changed the way people acted and felt about the space. Understanding this relationship is a crucial tool in applying the success of the Times Square transformation project to other areas of engineering.

Further Considerations

 * How has the development of transportation over time impacted the growth of Times Square?
 * How has choice architecture played a role in the transformation of Times Square?
 * How has COVID-19 impacted the use of space in Times Square?
 * How did the Great Depression cause the decline of Times Square?


text:
Neuroimaging Data Processing/Print version

= 1. Introduction =

= 2. Data =

= 2.1 Storage =

= 2.1.1 Filetypes =

= 2.1.1.1 DICOM =

= 2.1.1.2 NIfTI =

= 2.1.1.3 AFNI =

= 2.1.1.4 GIfTI =

= 2.1.2 Organization =

= 3. Processing =

= 3.1 Steps =

= 3.1.1 Discarding First Volumes =

= 3.1.2 Despiking =

= 3.1.3 Slice Timing =

= 3.1.4 Realignment =

= 3.1.5 Skull Stripping =

= 3.1.6 Tissue Segmentation =

= 3.1.7 Coregistration and Normalization =

= 3.1.8 Field Map Correction =

= 3.1.9 Physiological Noise Regression =

= 3.1.10 Temporal Filtering =

= 3.1.11 Smoothing =

= 3.1.12 Surface Extraction =

= 3.2 Tools =

= 3.2.1 SPM =

= 3.2.2 FSL =

= 3.2.3 AFNI =

= 4. References =

= 5. Glossary =


text:
LMIs in Control/Stability Analysis/Kharitonov-Bernstein-Haddad

Kharitonov-Bernstein-Haddad
Consider the set of matrices A = { $$ \begin{align} A = \begin{bmatrix} 0_{(n-1)\times 1} & 1_{(n-1)\times(n-1)}\\ -a_{0} & -a_{n-1}\\ \end{bmatrix} \qquad |\qquad \underline{a}_{j}\le \underline{a}_{j}\le \overline{a}_{j}, \qquad j=1,2,3,4,...,n-1 \end{align} $$ }

Every matrix in the set A is Hurwitz if and only if there exist $$P_{i}\in \text{S}^{n} $$, i = 1, 2, 3, 4, where Pi > 0, i = 1, 2, 3, 4, such that

\begin{align} \qquad P_{i}A_{i} + A_{i}^{T}P_{i}< 0      \qquad    i=1,2,3,4, \end{align} $$ where

$$ \begin{align} \qquad A_{i} = \begin{bmatrix} [0_{(n-1)\times 1} & 1_{(n-1)\times(n-1)}] \\ \qquad   a_{i} \\

\end{bmatrix} \end{align} ,\qquad   i=1,2,3,4, $$

$$ \begin{align} \qquad a_{1} =- \begin{bmatrix} \underline{a}_{0} & \underline{a}_{1} &\overline{a}_{2} &\overline{a}_{2} &... & \underline{a}_{n-4} & \underline{a}_{n-3} & \overline{a}_{n-2}& \overline{a}_{n-1} \end{bmatrix}, \end{align} $$

$$ \begin{align} \qquad a_{2} =- \begin{bmatrix} \underline{a}_{0} & \overline{a}_{1} &\overline{a}_{2} &\underline{a}_{2} &... & \underline{a}_{n-4} & \overline{a}_{n-3} & \overline{a}_{n-2}& \underline{a}_{n-1} \end{bmatrix}, \end{align} $$

$$ \begin{align} \qquad a_{3} =- \begin{bmatrix} \overline{a}_{0} & \underline{a}_{1} &\underline{a}_{2} &\overline{a}_{2} &... & \overline{a}_{n-4} & \underline{a}_{n-3} & \underline{a}_{n-2}& \overline{a}_{n-1} \end{bmatrix}, \end{align} $$

$$ \begin{align} \qquad a_{4} =- \begin{bmatrix} \overline{a}_{0} & \overline{a}_{1} &\underline{a}_{2} &\underline{a}_{2} &... & \overline{a}_{n-4} & \overline{a}_{n-3} & \underline{a}_{n-2}& \underline{a}_{n-1} \end{bmatrix}, \end{align} $$

Equivalently, every matrix in the set A is Hurwitz if and only if there exist $$Q_{i}\in \text{S}^{n} $$, i = 1, 2, 3, 4, where Qi > 0, i = 1, 2, 3, 4, such that

\begin{align} \qquad A_{i}Q_{i} + Q_{i}A_{i}^{T}< 0      \qquad    i=1,2,3,4, \end{align} $$