text:
1 Introduction

# BV solutions and viscosity approximations of rate-independent systems

## Abstract.

In the nonconvex case solutions of rate-independent systems may develop jumps as a function of time. To model such jumps, we adopt the philosophy that rate independence should be considered as limit of systems with smaller and smaller viscosity. For the finite-dimensional case we study the vanishing-viscosity limit of doubly nonlinear equations given in terms of a differentiable energy functional and a dissipation potential which is a viscous regularization of a given rate-independent dissipation potential.

The resulting definition of ‘BV solutions’ involves, in a nontrivial way, both the rate-independent and the viscous dissipation potential, which play a crucial role in the description of the associated jump trajectories.

We shall prove a general convergence result for the time-continuous and for the time-discretized viscous approximations and establish various properties of the limiting solutions. In particular, we shall provide a careful description of the jumps and compare the new notion of solutions with the related concepts of energetic and local solutions to rate-independent systems.

AMS Subject Classification: 49Q20, 58E99.

A.M. has been partially supported by DFG, Research Unit FOR 797 “MicroPlast”, Mi 459/5-1. R.R. and G.S. have been partially supported by a MIUR-PRIN’06 grant for the project “Variational methods in optimal mass transportation and in geometric measure theory”.

## 1. Introduction

Rate-independent evolutions occur in several contexts. We refer the reader to [32] and the forthcoming monograph [39] for a survey of rate-independent modeling and analysis in a wide variety of applications, which may pertain to very different and far-apart branches of mechanics and physics. Rate-independent systems present very distinctive common features, because of their hysteretic character [54, 24]. Driven by external loadings on a time scale much slower than their internal scale, such systems respond to changes in the external actions invariantly for time-rescalings. Thus, they in fact show (almost) no intrinsic time-scale. This kind of behavior is encoded in the simplest, but still significant, example of rate-independent evolution, namely the doubly nonlinear differential inclusion

 ∂Ψ0(u′(t))+DEt(u(t))∋0in X∗for a.a. t∈(0,T). (DN${}_{0}$)

For the sake of simplicity, we will consider here the case when is a finite dimensional linear space, an energy functional ( denoting the differential of with respect to the variable ), and is a convex, nondegenerate, dissipation potential, hereafter supposed positively homogeneous of degree . Thus, ((DN${}_{0}$)) is invariant for time-rescalings, rendering the system rate independence.

Since the range of is a proper subset of , when is not strictly convex one cannot expect the existence of an absolutely continuous solution of ((DN${}_{0}$)). Over the past decade, this fact has motivated the development of suitable notions of weak solutions to ((DN${}_{0}$)). In the mainstream of [18, 35, 44], the present paper aims to contribute to this issue. Relying on the vanishing-viscosity approach, we shall propose the notion of solution to ((DN${}_{0}$)) and thoroughly analyze it.

To better motivate the use of vanishing viscosity and highlight the features of the concept of solution, in the next paragraphs we shall briefly recall the other main weak solvability notions for ((DN${}_{0}$)). For the sake of simplicity, we shall focus on the particular case

 Ψ0(v)=∥v∥,for some norm ∥⋅∥ on X. (1.1)

#### Energetic and local solutions.

The first attempt at a rigorous weak formulation of ((DN${}_{0}$)) goes back to [40] and the subsequent [42, 41], which advanced the notion of global energetic solution to the rate-independent system ((DN${}_{0}$)). In the simplified case (1.1), this solution concept consists of the following relations, holding for all :

 ∀z∈X:Et(u(t))≤Et(z)+∥z−u(t)∥, ($\mathrm{S}$)
 Et(u(t))+Var(u;[0,t])=E0(u(0))+∫t0∂tEs(u(s))ds. ($\mathrm{E}$)

The energy identity (($\mathrm{E}$)) balances at every time the dissipated energy (the latter symbol denotes the total variation of the solution on the interval ), with the stored energy , the initial energy, and the work of the external forces. On the other hand, (($\mathrm{S}$)) is a stability condition, for it asserts that the change from the current state to another state brings about a gain of potential energy smaller than the dissipated energy. Since the competitors for range in the whole space , (($\mathrm{S}$)) is in fact a global stability condition.

The global energetic formulation (($\mathrm{S}$))–(($\mathrm{E}$)) only involves the (assumedly smooth) power of the external forces , and is otherwise derivative-free. Thus, it is well suited to jumping solutions. Furthermore, as shown in [27, 32], it is amenable to analysis in very general ambient spaces, even with no underlying linear structure. Because of its flexibility, this concept has been exploited in a variety of applicative contexts, like, for instance, shape memory alloys [42, 37, 5], crack propagation [15, 14, 17], elastoplasticity [29, 30, 31, 20, 10, 11, 28], damage in brittle materials [38, 6, 52, 33], delamination [23], ferroelectricity [43], and superconductivity [50].

On the other hand, in the case of nonconvex energies condition (($\mathrm{S}$)) turns out to be a strong requirement, for it may lead the system to change instantaneously in a very drastic way, jumping into very far-apart energetic configurations (see, for instance, [30, Ex. 6.1], [21, Ex. 6.3], and [35, Ex. 1]). On the discrete level, global stability is reflected in the global minimization scheme giving raise to approximate solutions by time-discretization. Indeed, for a fixed time-step , inducing a partition of the interval , one constructs discrete solutions of (($\mathrm{S}$))–(($\mathrm{E}$)) by setting and then solving recursively the variational incremental scheme

 Unτ∈missingArgminU∈X{∥U−Un−1τ∥+Etn(U)}for n=1,…,N. ($\mathrm{IP}_{0}$)

However, a scheme based on local minimization would be preferable, both in view of numerical analysis and from a modeling perspective, see the discussions in [30, Sec. 6] and, in the realm of crack propagation, [16, 45, 26].

As pointed out in [16], local minimization may be enforced by perturbing the variational scheme (($\mathrm{IP}_{0}$)) with a term, modulated by a viscosity parameter , which penalizes the squared distance from the previous step

 Extra open brace or missing close brace ($\mathrm{IP}_{\varepsilon}$)

and depends on a second norm , typically Hilbertian, on the space . In a infinite-dimensional setting, one may think of , with a domain in , , and , the and norms, respectively. Notice that, on the time-continuous level, (($\mathrm{IP}_{0}$)) corresponds to the viscous doubly nonlinear equation

 ∂Ψε(u′ε(t))+DEt(uε(t))∋0in % X∗for a.a. t∈(0,T),withΨε(v)=∥v∥+ε2|v|2 (DN${}_{\varepsilon}$)

(see [9, 8] for the existence of solutions ). Then, the idea would be to consider the solutions to ((DN${}_{0}$)) arising in the passage to the limit, in the discrete scheme (($\mathrm{IP}_{\varepsilon}$)), as and tend to simultaneously, keeping . One can guess that, at least formally, this procedure should be equivalent to considering the limit of the solutions to ((DN${}_{\varepsilon}$)) as .

Vanishing viscosity has by now become an established selection criterion for mechanically feasible weak solvability notions of rate-independent evolutions. We refer the reader to [25] for rate-independent problems with convex energies and discontinuous inputs, and, in more specific applied contexts, to [12] for elasto-plasticity with softening, to [19] for general material models with nonconvex elastic energies, the recent [13] for cam-clay non-associative plasticity, and [53, 21, 22] for crack propagation. Since the energy functionals involved in such applications are usually nonsmooth and nonconvex, the passage to the limit mostly relies on lower semicontinuity arguments. Let us illustrate the latter in the prototypical case ((DN${}_{\varepsilon}$)). The key observation is that ((DN${}_{\varepsilon}$)) is equivalent (see the discussion in Section 2.4) to the -energy identity

 Et(uε(t))+∫t0(∥u′ε(s)∥ds+ε2|u′ε(s)|2 +12εdist∗(−DEs(uε(s)),K∗)2)ds (1.2) =E0(u(0))+∫t0∂tEs(uε(s))ds

for all , where the term

 dist∗(−DEt(u(t)),K∗) :=minz∈K∗|−DEt(u(t))−z|∗,  with  K∗={z∈X∗:∥z∥∗≤1}, (1.3)

measures the distance with respect to the dual norm of from the set . The term defined in (1.3) is penalized in (1.2) by the coefficient . Thus, passing to the limit in (1.2) as , one finds

 dist∗(−DEt(u(t)),K∗)=0for% a.a.t∈(0,T).

Hence,

 −DEt(u(t))∈K∗,i.e.∥−DEt(u(t))∥∗≤1for a.a.t∈(0,T), (1.4)

which is a local version of the global stability (($\mathrm{S}$)). Furthermore, (1.2) yields, via lower-semicontinuity, the energy inequality

 Et(u(t))+Var(u;[0,t])≤E0(u(0))+∫t0∂tEs(u(s))ds%forall$t∈[0,T]$. (1.5)

Conditions (1.4)–(1.5) give raise to the notion of local solution of the rate-independent system ((DN${}_{0}$)).

While the local stability (1.4) is more physically realistic than (($\mathrm{S}$)), its combination with the energy inequality (1.5) turns out to provide an unsatisfactory description of the solution at jumps (see the discussion in [35, Sec. 5.2] and Remark 2.8 later on). In order to capture the jump dynamics, the energetic behavior of the system in a jump regime has to be revealed. From this perspective, it seems to be crucial to recover from (1.2), as , an energy identity, rather than an energy inequality. Thus, the passage to the limit has to somehow keep track of the limit of the term

 ∫t0(ε2|u′ε(s)|2+12εdist∗(−DEs(uε(s)),K∗)2)ds,

which in fact encodes the contribution of the viscous dissipation , completely missing in (1.5).

#### BV solutions.

Moving from these considerations, it is natural to introduce the vanishing viscosity contact potential (which is related to the bipotential discussed in [7], see Section 3) induced by , i.e. the quantity

 p(v,w):=infε>0(Ψε(v)+Ψ∗ε(w)) =infε>0(∥v∥+ε2|v|2+12εdist2∗(w,K∗)) (1.6) =∥v∥+|v|dist∗(w,K∗)for v∈X, w∈X∗.

Then, the -energy identity (1.2) yields the inequality

 Et(uε(t))+∫t0p(u′ε(s),−DEs(uε(s)))ds≤E0(u(0))+∫t0∂tEs(uε(s))ds, (1.7)

see Section 3.1. Passing to the limit in (1.7), in Theorem 4.10 we shall prove that, up to a subsequence, the solutions of the viscous equation ((DN${}_{\varepsilon}$)) converge, as , to a curve satisfying the local stability (1.4) and the following energy inequality

 Et(u(t))+\sl Varp,E(u;[0,t])≤E0(u(0))+∫t0∂tEs(u(s))ds. (1.8)

Without going into details (see Definition 3.4 later on), we may point out that (1.8) features a notion of (pseudo)-total variation (denoted by ) induced by the vanishing viscosity contact potential  (1.6) and the energy . The main novelty is that a -curve obeying the local stability condition (1.4) always satisfies the opposite inequality in (1.8), thus yielding the energy balance

 Et(u(t))+\sl Varp,E(u;[t,t])=E0(u(0))+∫t0∂tEs(u(s))ds. ($\mathrm{E}_{{{\mathfrak{p}}},{\mathcal{E}}}$)

In fact, provides a finer description of the dissipation of , along a jump between two values and at time : it involves not only the quantity related to the dissipation potential (1.1), but also the viscous contribution induced by the vanishing viscosity contact potential through the formula

 Δp,E(t;u−,u+):=inf{ Extra open brace or missing close brace (1.9) ϑ∈AC([r0,r1];X), ϑ(r0)=u−, ϑ(r1)=u+}.

By a rescaling technique, it is possible to show that, in a jump point, the system may switch to a viscous behavior, which is in fact reminiscent of the viscous approximation ((DN${}_{\varepsilon}$)). In particular, when the jump point is of viscous type, the infimum in (1.9) is attained and the states and are connected by some transition curve , fulfilling the viscous doubly nonlinear equation

 ∂Ψ0(ϑ′(r))+ϑ′(r)+DEt(ϑ(r))∋0in X∗for a.a.r∈(r0,r1)

(in the case the norm is Euclidean and we use its differential to identify with ). The combination of (1.4) and (1.8) yields the notion of solution to the rate-independent system . This concept was first introduced in [35], in the case the ambient space is a finite-dimensional manifold , and both the rate-independent and the viscous approximating dissipations depend on one single Finsler distance on . In this paper, while keeping to a Banach framework, we shall considerably broaden the class of rate-independent and viscous dissipation functionals, cf. Remark 2.4. Moreover, the notion of solution shall be presented here in a more compact form than in [35], amenable to a finer analysis and, hopefully, to further generalizations.

Let us now briefly comment on our main results. First of all, we are going to show in Theorems 4.3, 4.6, and 4.7 that the concept of rate-independent evolution completely encompasses the solution behavior in both a purely rate-independent, non-jumping regime, and in jump regimes, where the competition between dry-friction and viscous effects is highlighted. Indeed, from (1.4) and (1.8) it is possible to deduce suitable energy balances at jumps (cf. conditions ((J${}_{\mathrm{BV}}$)) in Theorem 4.3).

Then, in Theorem 4.10 we shall prove that, along a subsequence, the viscous approximations arising from ((DN${}_{\varepsilon}$)) converge as to a solution. Next, our second main result, Theorem 4.11, states that, up to a subsequence, also the discrete solutions constructed via the -discretization scheme (($\mathrm{IP}_{\varepsilon}$)) converge to a solution of ((DN${}_{0}$)) as and simultaneously, provided that the respective convergence rates are such that

 limε,τ↓0ετ=+∞.

Finally, in Section 5 we shall develop a different approach to solutions, via the rescaling technique advanced in [18] and refined in [35, 44]. The main idea is to suitably reparametrize the approximate viscous curves in order to capture, in the vanishing viscosity limit, the viscous transition paths at jumps points. This leads to performing an asymptotic analysis as of the graphs of the functions , in the extended phase space . For every the graph of can be parametrized by a couple of functions , being the (strictly increasing) rescaling function and the rescaled solution. In Theorem 5.6 we assert that, up to a subsequence, the functions converge as to a parametrized rate-independent solution. By the latter terminology we mean a curve fulfilling

 t:[0,S]→[0,T]% is nondecreasing, t′(s)+∥u′(s)∥>0for a.a.% s∈(0,S), (1.10a) t′(s)>0⟹∥−DEt(s)(u(s))∥≤1,∥u′(s)∥>0⟹∥−DEt(s)(u(s))∥≥1}for a.a.\ s∈(0,S), (1.10b) and the energy identity ddsE(t(s),u(s))−∂tE(t(s),u(s))t′(s)=−∥u′(s)∥−|u′(s)|dist∗(−DEt(s)(u(s)),K∗)for a.a.% s∈(0,S), (1.10c)

As already pointed out in [18, 35], like the notion of solution, relations (1.10) as well comprise both the purely rate-independent evolution as well as the viscous transient regime at jumps. The latter regime in fact corresponds to the case : the system does not obey the local stability constraint (1.4) any longer, and switches to viscous behavior, see also Remark 5.7 later on.

As a matter of fact, Theorem 5.8 shows that parametrized rate-independent solutions may be viewed as the “continuous counterpart” to evolutions. With a suitable transformation, it is possible to associate with every parametrized rate-independent solution a one, and conversely. One advantage of the parametrized notion is that it avoids the technicalities related to functions. Hence, it is for instance more easily amenable to a stability analysis (cf. [35, Rmk. 6]). Furthermore, in [44] a highly refined vanishing viscosity analysis has been developed, with this reparametrization technique, in the infinite-dimensional -framework, where ((DN${}_{\varepsilon}$)) is replaced by a general quasilinear evolutionary PDE.

#### Generalizations and future developments.

So far we have focused on dissipation functionals of the type (1.1) and as in ((DN${}_{\varepsilon}$)) for expository reasons only, in order to highlight the main variational argument leading to the notion of solution. Indeed, the analysis developed in this paper is targeted to a general

 positively 1-homogeneous, convex dissipation Ψ0:X→[0,+∞),

(cf. (2.1)), and considers a fairly wide class of approximate viscous dissipation functionals , defined by conditions (($\Psi.1$))–(($\Psi.3$)) in Section 2.3. Furthermore, at the price of just technical complications, our results could be extended to the case of a Finsler-like family of dissipation functionals , depending on the state variable , and satisfying uniform bounds and Mosco-continuity with respect to , see [35, Sect. 2] and [47, Sect. 6, 8].

The extension to infinite-dimensional ambient spaces and nonsmooth energies is crucial for application of the concept of solution to the PDE systems modelling rate-independent evolutions in continuum mechanics. A first step in this direction is to generalize the known existence results for doubly nonlinear equations, driven by a viscous dissipation, to nonconvex and nonsmooth energy functionals in infinite dimensions. As shown in [48, 47], in the nonsmooth and nonconvex case one can replace the energy differential with a suitable notion of subdifferential . Accordingly, instead of continuity of , one asks for closedness of the multivalued subdifferential in the sense of graphs. These ideas shall be further advanced in the forthcoming work [36]. Therein, exploiting techniques from nonsmooth analysis, we shall also tackle energies which do not depend smoothly on time (this is relevant for rate-independent applications, see e.g. [22] and [25]).

On the other hand, the requirement that the ambient space is finite-dimensional could be replaced by suitable compactness (of the sublevels of the energy) and reflexivity assumptions on the ambient space . The latter topological requirement in fact ensures that has the so-called Radon-Nikodým property, i.e. that absolutely continuous curves with values in are almost everywhere differentiable. The vanishing viscosity analysis in spaces which do not enjoy this property requires a subtler approach, involving metric arguments (see e.g. [47, Sect. 7]), or ad-hoc stronger estimates [44]. See also [34] for some preliminary approaches to BV solutions for PDE problems.

### Plan of the paper

Section 2 is devoted to an extended presentation of energetic and local solutions to rate-independent systems. In particular, after fixing the setup of the paper in Section 2.1, in Sec. 2.2 we recall the definition of global energetic solution, show its differential characterization and the related variational time-incremental scheme. We develop the vanishing-viscosity approach in Secs. 2.3 and 2.4, thus arriving at the notion of local solution (see Section 2.5), which also admits a differential characterization.

In Section 3 we introduce the concept of vanishing viscosity contact potential and thoroughly analyze its properties, as well as the induced (pseudo)-total variation. With these ingredients, in Sec. 4 we present the notion of solution. We show that rate-independent evolutions admit, too, a differential characterization, and, in Sec. 4.2, that they provide a careful description of the energetic behavior of the system. Then, in Section 4.3, we state our main results on solutions.

While Section 5 is focused on the alternative notion of parametrized rate-independent solutions, the last Sec. 6 contains some technical results which lie at the core of our theory.

## 2. Global energetic versus local solutions, and their viscous regularizations

In this section, we will briefly recall the notion of energetic solutions and show that their viscous regularizations give raise to local solutions.

### 2.1. Rate-independent setting: dissipation and energy functionals

We let

 (X,∥⋅∥X)   be a finite-dimensional normed vector space,

endowed with a gauge function , namely a

 non-degenerate, positively 1-homogeneous, convex dissipation Ψ0:X→[0,+∞), (2.1)

i.e.  satisfies if , and

 Ψ0(v1+v2)≤Ψ0(v1)+Ψ0(v2),Ψ0(λv)=λΨ0(v)for every λ≥0, v,v1,v2∈X.

In particular, there exists a constant such that

 η−1∥v∥X≤Ψ0(v)≤η∥v∥Xfor every v∈X.

Since is -homogeneous, its subdifferential can be characterized by

 ∂Ψ0(v):={w∈X:⟨w,z⟩≤Ψ0(z)%foreveryz∈X,⟨w,v⟩=Ψ0(v)}⊂X∗; (2.2)

takes its values in the convex set , given by

 K∗=∂Ψ0(0):={w∈X∗:⟨w,z⟩≤Ψ0(z)∀z∈X}⊃∂Ψ0(v)for every v∈X, (2.3)

which enjoys some useful (and well-known, see e.g. [46]) properties. For the reader’s convenience we list them here:

1. is the proper domain of the Legendre transform of , since

 Ψ∗0(w)=IK∗(w)={0if w∈K∗,+∞otherwise. (2.4)
2. is the support function of , since

 Ψ0(v)=supw∈K∗⟨w,v⟩for every v∈X, (2.5)

and is the polar set of the unit ball associated with .

3. is the unit ball of the support function of :

 K∗={w∈X∗:Ψ0∗(w)≤1},withΨ0∗(w)=supv∈K⟨w,v⟩=supv≠0⟨w,v⟩Ψ0(v). (2.6)
4. In the even case (i.e., when for all ), we have that is an equivalent norm for , is its dual norm, and are their respective unit balls.

Further, we consider a smooth energy functional

 E∈C1([0,T]×X),

which we suppose bounded from below and with energy-bounded time derivative

 ∃C>0 ∀(t,u)∈[0,T]×X:Et(u)≥−C,|∂tEt(u)|≤C(1+Et(u)+), (2.7)

where denotes the positive part. The rate-independent system associated with the energy functional and the dissipation potential can be formally described by the rate-independent doubly nonlinear differential inclusion

 ∂Ψ0(u′(t))+DEt(u(t))∋0in X∗for a.a. t∈(0,T). (DN${}_{0}$)

As already mentioned in the Introduction, for nonconvex energies solutions to ((DN${}_{0}$)) may exhibit discontinuities in time. The first weak solvability notion for ((DN${}_{0}$)) is the concept of (global) energetic solution to the rate-independent system ((DN${}_{0}$)) (see [42, 40, 41] and the survey [32]), which we recall in the next section.

### 2.2. Energetic solutions and variational incremental scheme

###### Definition 2.1 (Energetic solution).

A curve is an energetic solution of the rate independent system if for all the global stability (S) and the energy balance (E) holds:

 ∀z∈X:Et(u(t))≤Et(z)+Ψ0(z−u(t)), (S)
 Et(u(t))+VarΨ0(u;[0,t])=E0(u(0))+∫t0∂tEs(u(s))ds. (E)

#### BV functions.

Hereafter, we shall consider functions of bounded variation pointwise defined in every point , such that the pointwise total variation with respect to (any equivalent norm of can be chosen) is finite, where

 Missing or unrecognized delimiter for \Big

Notice that a function in admits left and right limits at every

 u(t−):=lims↑tu(s),  u(t+):=lims↓tu(s),  with the convention u(0−):=u(0), u(T+):=u(T), (2.8)

and its pointwise jump set is the at most countable set defined by

 Ju:={t∈[0,T]:u(t−)≠u(t) or u(t)≠u(t+)}⊃\rm ess-Ju:={t∈[0,T]:u(t−)≠u(t+)}. (2.9)

We denote by the distributional derivative of , and recall that is a Radon vector measure with finite total variation . It is well known [3] that can be decomposed into the sum of the three mutually singular measures

 u′=u′L+u′C+u′J,u′L=˙uL1,u′co:=u′L+u′C. (2.10)

Here, is the absolutely continuous part with respect to the Lebesgue measure , whose Lebesgue density is the usual pointwise (and -a.e. defined) derivative, is a discrete measure concentrated on , and is the so-called Cantor part, still satisfying for every . Therefore is the diffuse part of the measure, which does not charge . In the following, it will be useful to use a nonnegative and diffuse reference measure on such that and are absolutely continuous w.r.t. : just to fix our ideas, we set

 μ:=L1+|u′C|. (2.11)

With a slight abuse of notation, for every we denote by the integral

 Missing or unrecognized delimiter for \left (2.12)

Since is -homogeneous, the above integral is independent of , provided is absolutely continuous w.r.t. .

#### Towards a differential characterization of energetic solutions.

Let us first of all point out that ((S)) is stronger than the local stability condition

 −DEt(u(t))∈K∗for every t∈[0,T]∖Ju, ($\mathrm{S}_{\mathrm{loc}}$)

which can be formally deduced from ((DN${}_{0}$)) and (2.3). Indeed, the global stability ((S)) yields for every and

 ⟨−DEt(u(t)),hv⟩+o(|h|)≤Et(u(t))−Et(u(t)+hv)≤hΨ0(v)

and therefore, dividing by and passing to the limit as , one gets

 ⟨−DEt(u(t)),v⟩≤Ψ0(v)% for every z∈X,

so that (($\mathrm{S}_{\mathrm{loc}}$)) holds. We obtain more insight into ((E)) by representing the variation in terms of the distributional derivative of . In fact, recalling (2.11) and (2.12), we have

where the jump contribution can be described, in terms of the quantities

 ΔΨ0(v0,v1):=Ψ0(v1−v0),ΔΨ0(v−,v,v+):=Ψ0(v−v−)+Ψ0(v+−v), (2.13)

by

 JmpΨ0(u;[a,b]):=ΔΨ0(u(a),u(a+))+ΔΨ0(u(b−),u(b))+∑t∈Ju∩(a,b)ΔΨ0(u(t−),u(t),u(t+)). (2.14)

Also notice that, as usual in rate-independent evolutionary problems, is pointwise everywhere defined and the jump term takes into account the value of at every time . Therefore, if is not continuous at , this part may yield a strictly bigger contribution than the total mass of the distributional jump measure (which gives rise to the so-called essential variation).

The following result provides an equivalent characterization of energetic solutions: besides the global stability condition ((S)), it involves a formulation of the differential inclusion ((DN${}_{0}$)) (cf. the subdifferential formulation of [41]) and a jump condition at any jump point of .

###### Proposition 2.2.

A curve satisfying the global stability condition ((S)) is an energetic solution of the rate-independent system if and only if it satisfies the differential inclusion

 ∂Ψ0(du′codμ(t))+DEt(u(t))∋0for μ-a.e.\ t∈[0,T],μ:=L1+|u′C|, (DN${}_{0,\mathrm{BV}}$)

and the jump conditions

 Et(u(t))−Et(u(t−))=−ΔΨ0(u(t−),u(t)),Et(u(t+))−Et(u(t))=−ΔΨ0(u(t),u(t+)),Et(u(t+))−Et(u(t−))=−ΔΨ0(u(t−),u(t+)). (J${}_{\text{ener}}$)

for every (recall convention (2.8) in the case ).

We shall simply sketch the proof, referring to the arguments for the forthcoming Proposition 2.7 for all details.

###### Proof.

By the additivity property of the total variation , ((E)) yields for every

 VarΨ0(u;[t0,t1])+Et1(u(t1))=Et0(u(t0))+∫t1t0∂tEt(u(t))dt. (E’)

Arguing as in the proof of Proposition 2.7 later on, one can see that the global stability ((S)) and ((E’)) yield the differential inclusion ((DN${}_{0,\mathrm{BV}}$)) and conditions ((J${}_{\text{ener}}$)).

Conversely, repeating the arguments of Proposition 2.7 one can verify that ((DN${}_{0,\mathrm{BV}}$)) and ((J${}_{\text{ener}}$)) imply ((E)). ∎

#### Incremental minimization scheme

Existence of energetic solutions can be proved by solving a minimization scheme, which is also interesting as construction of an effective approximation of the solutions.

For a given time-step we consider a uniform partition (for simplicity) , , of the time interval , and an initial value . In order to find good approximations of we solve the incremental minimization scheme

 Extra open brace or missing close brace (IP${}_{0}$)

Setting

 ¯¯¯¯Uτ(t):=Unτif t∈(tn−1,tn], (2.15)

it is possible to find a suitable vanishing sequence of step sizes (see, e.g., [41, 32] for all calculations), such that

 ∃ limk→+∞¯¯¯¯Uτk(t)=:u(t)%foreveryt∈[0,T],

and is an energetic solution of ((DN${}_{0}$)).

### 2.3. Viscous approximations of rate-independent systems

In the present paper we want to study a different approach to approximate and solve ((DN${}_{0}$)): the main idea is to replace the linearly growing dissipation potential with a suitable convex and superlinear “viscous” regularization of , depending on a “small” parameter and “converging” to in a suitable sense as . Solving the doubly nonlinear differential inclusion (we use the notation for the time derivative when is absolutely continuous)

 ∂Ψε(˙uε(t))+DEt(uε(t))∋0in X∗ \quad for a.a. t∈(0,T), (DN${}_{\varepsilon}$)

one can consider the sequence as a good approximation of the solution of ((DN${}_{0}$)) as .

There is also a natural discrete counterpart to ((DN${}_{\varepsilon}$)), which regularizes the incremental minimization problem ((IP${}_{0}$)). We simply substitute by in ((IP${}_{0}$)), recalling that now the time-step should explicitly appear, since is not -homogeneous any longer. The viscous incremental problem is therefore

 find U1τ,ε,⋯,UNτ,εsuch thatUnτ,ε∈missingArgminU∈X{τΨε(U−Un−1τ,ετ)+Etn(U)}. (IP${}_{\varepsilon}$)

Setting as in (2.15)

 ¯¯¯¯Uτ,ε(t):=Unτ,εif t∈(tn−1,tn],

one can study the limit of the discrete solutions when and , under some restriction on the behavior of the quotient (see Theorem 4.11 later on).

#### The choice of the viscosity approximation Ψε.

Here we consider the particular case when the potential can be obtained starting from a given

 convex function Ψ:X→[0,+∞)such thatΨ(0)=0,lim∥v∥X↑+∞Ψ(v)∥v∥X=+∞, ($\Psi.1$)

by the canonical rescaling

 Ψε(v):=ε−1Ψ(εv)for every% v∈X, ε>0, ($\Psi.2$)

and is linked to by the relation

 Ψ0(v)=limε↓0Ψε(v)=limε↓0ε−1Ψ(εv)for % every v∈X. ($\Psi.3$)
###### Remark 2.3.

Notice that, by convexity of and the fact that , the map is nondecreasing for all . Hence,

 Ψ0(v)≤Ψε(v)for all v∈X, for all ε>0. (2.16)

Furthermore, by the coercivity condition (($\Psi.1$)),

 ∂Ψε(v):=∂Ψ(εv)is a % surjective map.

Here are some examples, showing that (($\Psi.2$)) still provides a great flexibility and covers several interesting cases.

###### Example 2.4.
• The simplest example, still absolutely non trivial [35], is to consider

 Ψ(v):=Ψ0(v)+12(Ψ0(v))2,Ψε(v):=Ψ0(v)+ε2(Ψ0(v))2,∂Ψε(v)=(1+εΨ0(v))∂Ψ0(v). (2.17)

A similar regularization can be obtained by choosing a real convex and superlinear function , with , and setting

 Ψ(v):=Ψ0(v)+FV(Ψ0(v))=F(Ψ0(v)),with  F(r):=r+FV(r). (2.18)
• The most interesting case involves an arbitrary norm on and considers for

 Ψ(v)=Ψ0(v)+1p∥v∥p,Ψε(v)=Ψ0(v)+εp−1p∥v∥p,∂Ψε(v)=∂Ψ0(v)+εp−1Jp(v), (2.19)

where is the -duality map associated with . In particular, if is a Hilbertian norm and , then is the Riesz isomorphism and we can choose by identifying with . Hence, ((DN${}_{\varepsilon}$)) reads

 ∂Ψε(˙uε(t))+ε˙uε(t)+DEt(uε(t))∋0in X∗ \quad for a.a. t∈(0,T),

and the incremental problem ((IP${}_{\varepsilon}$)) looks for which recursively minimizes

 U↦Ψ0(U−Un−1τ,ε)+ε2τ∥U−Un−1ε,τ∥2+Etn(U).

This is the typical situation which motivates our investigation.

• More generally, we can choose a convex “viscous” potential satisfying

 limε↓0ε−1ΨV(εv)=0,limλ↑+∞λ−1ΨV(λv)=+∞%forall$v∈X,$ (2.20)

and set

 Ψ(v):=Ψ0(v)+


text:
Back of the Envelope

Observations on the Theory and Empirics of Mathematical Finance

BR: Brownian Motion – I

BR’s third chapter forms the core of the book. Here they take the intuition developed in ‘Discrete Processes’ to a more formal continuous setting. The chapter can be seen as divided into three parts:

• Brownian Motion
• Ito Calculus
• Change of Measure

In this post we briefly take a look at BR’s treatment of the construction of Brownian Motion (BM).

Looking at a real time series of asset returns, BR argue that BM, prima facie, offers a good way of characterizing it. Not only is BM “…sophisticated enough to produce interesting models, but is simple enough to be tractable” mathematically. Even though a real financial time series is ‘noisier’ than the paths generated by BM, it offers a ‘basis’ to build more sophisticated continuous processes with.

Like in most other introductory textbooks, BR also develop BM from the simple binomial setting. Their treatment is quite concise, and not the most formal (i.e. starting with definitions etc.), but is clear enough to be understandable.

The Binomial Random Walk

A binomial random walk $W_n(t)$ is defined as:

$W_n(\frac{i}{n}) = W_{n}(\frac{i - 1}{n}) + \displaystyle \frac{X_i}{\sqrt{n}}$

where $X_i$ are a sequence of independent binomial random variables taking values $+1$ or $-1$ with equal probability – i.e. after each time step the change in the value of the random walk is either $\frac{1}{\sqrt{n}}$ or $-\frac{1}{\sqrt{n}}$.

Given that the jump sizes are scaled by the inverse of $\sqrt{n}$, BR show that this “…seems to force some kind of convergence” – in that the binomial random walk $W_n(t)$ doesn’t “blow up”. To see this, write:

\begin{aligned} W_n(\frac{nt}{n}) &= W_{n}(\frac{nt - 1}{n}) + \displaystyle \frac{X_{nt}}{\sqrt{n}} \\&= W_{n}(\frac{nt - 2}{n}) + \displaystyle \frac{X_{nt-1}}{\sqrt{n}} + \displaystyle \frac{X_{nt}}{\sqrt{n}}\end{aligned}

Recursively expanding $W_n(\frac{nt - i}{n})$ and using $W_n(0) = 0$ gives:

$W_n(t) = \sqrt{t} \Big(\frac{\displaystyle\sum_{i = 1}^{nt} X_i}{\displaystyle\sqrt{nt}}\Big)$

where we have multiplied both the numerator and denominator by $\sqrt{t}$.

From the central limit theorem, for $n$ large, the term in parentheses above tends to a Gaussian $N(0, 1)$ distribution, implying that the distribution of $W_n(t)$ tends to a Gaussian $N(0, t)$ distribution.

The moral of the story is that at the end of any time $nt$, the distribution of the sum $W_n(t)$ tends to Gaussian – i.e. at the end of any time the distribution of possible values of the random walk is Gaussian. This completes the characterization of the BM in the binomial setting. Let $n \rightarrow \infty$ and we have constructed our BM/Wiener Process in continuous time.

They go and define the continuous BM formally. It’s standard stuff and there are no surprises here. But I like their concise description of the construction of BM – it assumes certain comfort level with probability theory, but is quite succint and to-the-point.

Next: From BM as a ‘basis’ to a stochastic process for asset returns.

format: plain


text:
# Ducttape the Ducttape

Your boss has found out that quite a bunch of his employees (including you) like to steal code from others. He ordered you to write him a program that he can use to find people who steal code from others.

Write a program/function that detects if somebody copied (part of) his code from somewhere else.

The program will get all the existing programs and the program that it should test from two separate inputs. Edit: Since there are no answers so far, you may use regular expressions!

## Output

• The program should then output all the stolen pieces of code, separated by either a space or a newline. (It may have a space or a newline at the end.)
• A piece of code is considered to be stolen/copied if it consists of 10 or more successive bytes. (Sorry, Java fans!)
• You have to output as much as possible, but if there are overlapping ones, you may ignore one of them or output both of them.

## Twist:

As mentioned before, you also love duct tape coding. That means, everything in your code will be copy-pasted from a stack exchange site! You can copy whatever you want (not limited to code in code blocks) and as much as you want. (But at least 10 bytes) (Same rule as above about what is considered to be stolen/copied.) (Please do note that any answers that were posted after this question may not be used.) Please provide links to where you got your code from.

## Examples:

Input:
x = document.getElementById("ninja'd"); (The first input)
y = document.getElementById("id"); (The second input)

Output:

 = document.getElementById("

Input:
foo (The first input)
foo+bar (The second input)

Output:
Nothing.

Input:
public static void main(String[] args) (The first input)
public static void main(String[] args) (The second input)

Output:

 main(String[] args)

Input:
for(var i=0; i<x.length; i++){} (The first input)
for(var i=0; i<oops.length; i++){break;} (The second input)

Output:

for(var i=0; i<
.length; i++){

or

for(var i=0; i< .length; i++){

• It's missing rules for which strings can be copied and how (for the code). – feersum Nov 23 '15 at 18:27
• Do the copied strings have to come from code blocks, or any parts of an SE answer? If it comes from a code block does it need to use the entire block, or can a substring be used? Can the strings come from either the formatted text or the Markdown source? Can code blocks newer than this question be used? Can old revisions of a question be used? – feersum Nov 23 '15 at 18:35
• You say the substrings have to length 10 or more. Can I place a substring inside another substring? (Do the substrings have to be continuous?) – Blue Nov 23 '15 at 20:12
• @sysreq I decided to allow regular expressions! – Stefnotch Nov 24 '15 at 17:45
• Easy answer: Use Unary – lirtosiast Nov 24 '15 at 17:51

# Python 2, 224 bytes

from difflib import SequenceMatcher
def similar(a, b):
return SequenceMatcher(None, a, b).get_matching_blocks()
a=raw_input()
b=raw_input()
for start, _, size in similar(a, b):
if(size > 9):
print a[start:start+size]

from difflib import SequenceMatcher
def similar(a, b):
return SequenceMatcher(None, a, b).

get_matching_blocks() is copied from this answer

a=raw_input()
b=raw_input()

is copied from this question

for start, _, size in is copied from this answer and the second occurence of similar(a, b) is copied from the same place as the first.

if(size > 9) is copied from this question.

:
print

is copied from this question

a[start: is copied from this answer.

and finally, start+size] is copied from this questipn

Finally answered after one and a half years ...

• +1 Though, stackoverflow.com/questions/37386311/… was posted after this challenge was posted. I decided to remove that restriction, so your answer is fine. :) – Stefnotch Jul 13 '17 at 15:36
• @Stenfoch You don't need to; an earlier answer contains the same phrase – pppery Jul 13 '17 at 16:14
• One thing I learned about duct-tape-coding challenges: It is tricky to keep track of where you got all of your code. – pppery Jul 13 '17 at 16:19
• Wow, the score of this post has been rising very quickly ... – pppery Jul 14 '17 at 22:49


text:
Introduction
Conditional statements
Summary
18. Congratulations

## Instruction

Wow, excellent! You've managed to answer all questions related to if statements. Congratulations, and see you in the next part!

## Exercise

Click to finish this part.


text:
#### Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Click to Chat

1800-1023-196

+91-120-4616500

CART 0

• 0
MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping

# The plane x + 2y – z = 4 cuts the sphere x2 + y2 + z2 – x + z – 2 = 0 in a circle of radius ?

SHAIK AASIF AHAMED
6 years ago
Hello student,
Perpendicular distance of centre(1/2,0,-1/2)from x + 2y – 2 = 4
=(|1/2+1/2-4|)/$\sqrt{6}=\sqrt{3/2}$
So radius=$\sqrt{5/2-3/2}=1$
Thanks and Regards
Shaik Aasif


text:
# All Questions

3,297 questions
Filter by
Sorted by
Tagged with
23k views

### My prefix is food, my suffix is rude

I thought of this riddle myself. Feedback is appreciated. My prefix is food. My suffix is rude. My infix comes in rounds. I keep you off the ground. What am I?
9k views

### Interview Question or Pathbreaking puzzle

I thought this changes the way series of numbers are looked at 1 1 1 2 1 1 2 1 1 Write down the next three lines
1.0m views

### Two doors with two guards - one lies, one tells the truth

You are a prisoner in a room with 2 doors and 2 guards. One of the doors will guide you to freedom and behind the other is a hangman --you don't know which is which. One of the guards always tells ...
3k views

### Vowelburger™ Riddle

(A new kind of riddle) I ordered 5 Vowelburgers™ with buns and meat only - help me identify each one from the description on the menu!  % custom template - do not reuse \def\S#1#2{\Space{#1}{20px}{#...
91k views

### Twelve balls and a scale

You are given twelve identical-looking balls and a two-sided scale. One of the balls is of a different weight, although you don't know whether it's lighter or heavier. How can you use just three ...
5k views

### Word Riddle - you love me or you hate me

With two I’m affirmative With three I’m respectful With four I’m more respectful With all five I’m either loved or hated But when I’m loved, I kill; and when I’m hated, I may save lives.
3k views

### Introducing Gladys, an intrepid globetrotter

Gladys has always led an active life full of adventure. As a retiree, she has a lot of free time on her hands and loves to spend it on her two favourite pastimes – travelling and crossword ...
8k views

### Cryptic Clue Guide

This post is not a puzzle. There is nothing puzzly hidden inside it or the self-answer, posted at the same time. What exactly is a cryptic crossword clue, and how do I write one?
3k views

### The first Density™ Puzzle!

Welcome to the very first puzzle in a new series! It's all about (hopefully) exploring new ways of creating puzzles, as densely as possible. If you'd like to create your own Density™ puzzle, the ...
8k views

### A general solution to the decanting problem? (aka jug-pouring, water-pouring)

Take a look at these two questions: - A Set of Water Jug Challenges - Pouring problem Now I'm asking for a generalised solution to that problem. I define the problem as follows: You are required ...
80k views

### In the 100 blue eyes problem - why is the oracle necessary?

The riddle Randall Munroe (of xkcd fame) has, a bit hidden on his site, a logic puzzle: A group of people with assorted eye colors live on an island. They are all perfect logicians -- if a ...
6k views

### Burning ropes as timers

You have 2 identical ropes which burn at a specific rate, and an unlimited supply of matches. When you light one end of a rope, the fire will take exactly 1 hour to travel to the other end of the rope....
3k views

### Determine the algorithm

So I was given this puzzle quite some time ago and just thought it would make a nice addition to this site: Your task is to determine the method how the result is determined from the given number. A ...
4k views

### Which switch goes to which bulb?

You are in a room with three switches, labeled $A$, $B$, and $C$. Initially, each switch is in an off state. In an adjoining room, there are three incandescent light bulbs. Your task is to ...
18k views

### Oh, it is greater than God!

What is greater than God, worse than evil, The poor have it, the rich require it, And if you eat it, you die? What is it?
11k views

### Coin weighing problem

You are given ten stacks of golden coins, each stack consisting of ten coins and a digital scale with arbitrary precision. You know that all stacks of coins are made from gold, weighing 10 grams per ...
2k views

19k views

### Learning to Solve a River Crossing Puzzle

I have seen many variations of the following puzzle: Once upon a time, a farmer went to the market and purchased a fox, a goose, and a bag of beans. On his way home, the farmer came to the bank of ...
20k views

### Why is a single-corner twist not a valid position on a Rubik's cube?

For those of you familiar with the solution to the Rubik's cube, you will know that a single-corner twist is not a valid position. It can neither be attained by scrambling, nor can it be solved if it ...
951 views

### (1 of 11: Numberlink) What is Pyramid Cult's Favorite Activity?

Dear PSE users and moderators, I’m new here in PSE, but I really need your help. There was this person who gave me a black envelope consisting 10+1 pages of puzzles, and also a scribble saying: “Find ...


text:
# ant-dev mailing list archives

##### Site index · List index
Message view
Top
From bugzi...@apache.org
Subject DO NOT REPLY [Bug 3219] - pvcs task does not create folders
Date Wed, 12 Jun 2002 14:42:07 GMT
DO NOT REPLY TO THIS EMAIL, BUT PLEASE POST YOUR BUG
RELATED COMMENTS THROUGH THE WEB INTERFACE AVAILABLE AT
<http://nagoya.apache.org/bugzilla/show_bug.cgi?id=3219>.
INSERTED IN THE BUG DATABASE.

http://nagoya.apache.org/bugzilla/show_bug.cgi?id=3219

pvcs task does not create folders

To clarify for Stefan: the pvcs task has 2 steps for a checkout 1) it asks pvcs
for a list of all the files in a project, 2) is iterates through the results and
does a GET for each one.*  The results of step 1) are lines the look like this
(for me):

"P:\pvcs\develop\dev_db\archives\Custom Shared Components\Java\SIC\framework\lib
\turbine-pool.jar_v(C:\safti\lib\turbine-pool.jar)"

plus some other gunk.

the two things that can vary are the initial 1 or 2 characters of a line,
originally just / or \\ but I added in the ability to recognize any string with
the linestart attribute and set it to "P, which in xml is "P.  The archive
suffix at my company is _v, but the original code had it as _arc, the default
which is retained for backwards compatiblity, and some people use -arc.  So the
filenameFormat is {0}_arc({1}) and MessageFormat uses that to parse the lines above.

So in otherwords, the default is:

P:\path\to\archive_arc(workfile\path)

and the slashes can be either forward or backward, it's irrelevant.

If your repository is on a drive other than P:, change lineStart.  If your
repository suffix is something other than _arc, change filenameFormat.

Clear as mud?

*Don't ask me why pvcs is this way.  I use it, but it's by far the clunkiest
version control system I've ever used.

--
To unsubscribe, e-mail:   <mailto:ant-dev-unsubscribe@jakarta.apache.org>


text:
#### Ryan M

Joined Apr 2, 2019
10
Hello, I'm looking for help on building a transmitter & receiver to replace the wired connections on my Electric Drum Kit. The drum kit currently passes a signal from the drum pad to the computer brain module when the pad gets struck by a stick via basic stereo or mono cables, the same cable you'd use to connect an mp3 player to aux-in of a stereo, either 3.5mm(1/8") or 1/4" jack cable like a guitar would use.

I'd just like to make these connections wireless as there are at least 15 drums and cymbals connected to the rack and each needs its own mono channel to send the signal to the brain module when its hit. The computer does most the work, The pad basically has a sensor called a "paizo" and I imagine it produces a small electric signal when the pad is hit at a certain threshold and sends it through the cable.

They currently sell 1/4" transmitter/receiver systems for guitars starting at around $40, which I'd be happy to use as a solution if one piece was enough, but like i said earlier each drum/cymbal has a dedicated channel so it would cost over$500 to complete this project (more than the kit itself costs). I've seen professional bands use these for guitars when on stage in a show. I also don't need a high quality reproduction of the signal like a guitar performer would need because this wouldn't be used for generating sound, it just needs to carry a a weak inaudible signal to fire the trigger. There are youtube tutorials on building these but the parts are still relatively expensive for they are building the ones with high sound quality reproduction.

I believe such devices for guitars are built using UHF and ive seen some at 900mhz probably because latency is the biggest issue when sending wireless signals, and in order to fool the human ear and be able to play along, latency needs to be below 11 ms i believe. UHF accomplished this i imagine.

Any help for the parts and schematics would be appreciated.

-Ryan

#### Ryan M

Joined Apr 2, 2019
10
I'm considering trying something like he attachment here, This is for a camera. It is to trigger the flash wirelessly. Depending on how difficult & expensive this project is, and whether something like this will work, I'm considering just purchasing ten of these to clean up the clutter unless someone has some ideas for how i can achieve what im looking to build. I dont mind if the project takes a long time because I'll take it on one cable replacement at a time. Perhaps 2 per month and that way it gets done no rush in the year 2019. I enjoy the task as well, and i treat it as a hobby

#### Attachments

• 62 KB Views: 6

#### Sensacell

Joined Jun 19, 2012
2,567
This is going to be more difficult than you imagine.

It's a bit like saying "I want to build a phone charger that can charge my phone 20 feet away"
The idea sounds attractive, it's technically possible under very limited circumstances, but not very practical.

Clearly, if this was technically easy to do, every E-drum manufacturer would have this feature, the benefits are obvious.
The trouble is that you must be able to handle simultaneous triggers, meaning that you need 10 non-interfering channels that operate totally asynchronously, with very low latency.

Really cannot think of any practical solutions.
The plug-in wires start to seem like a really sexy solution.

#### Yaakov

Joined Jan 27, 2019
1,612
The signals from your drum kit are not going to be able to be directly transmitted via radio. For each piece of kit, you will need the front end processing the brain module is doing on the signal to be done locally, then the signal will have to be transmitted to a box outside the brain module that converts the signal back to what looks like raw drum kit output.

In addition, this will introduce, possibly not small amounts of, latency. The delay could really screw things up.

While this is theoretically possible, it is not practical. Maybe you could find a way to put the brain closer, and use wireless for the audio.

#### DickCappels

Joined Aug 21, 2008
6,378
Given enough thought this might turn out to be easier than it first appears. It would probably require some custom hardware and some programming.

How much latency can you accept? (The time between the drumpad being struck and receiving a signal from the receiver.)

#### Ryan M

Joined Apr 2, 2019
10
Thanks for the comments guys! I agree that if it could be done then everyone would be doing it (That's my plan eventually, so who has a degree in marketing and who knows some investors LOL)

@DickCappels: Latency will probably be the deal breaker im guessing if anything, but research has show that 10 milliseconds or less is required to be able to play along accurately or else the audio will not feel linked to the pads being hit and the timing will be thrown off with any delays higher than 11 millisecs.

That said, I am working toward my degree in computer science so I have a fair amount of coding C++, Python & Java beneath my belt. So, If you have a solution with any amount of latency, I'm game to try it on one drum as an experiment, and will return with results and some pictures/video of the process and video w/ audio of the results showing latency and quality. If it works in the end I'd be forever grateful as I'll potentially be saving myself hundreds of hours over the coming years (I'll explain in a later post why mobility is a must and unfortunately its not just something that gets setup and left alone like I had originally anticipated with electric drums).

#### Ryan M

Joined Apr 2, 2019
10
This is going to be more difficult than you imagine.

It's a bit like saying "I want to build a phone charger that can charge my phone 20 feet away"
The idea sounds attractive, it's technically possible under very limited circumstances, but not very practical.

Clearly, if this was technically easy to do, every E-drum manufacturer would have this feature, the benefits are obvious.
The trouble is that you must be able to handle simultaneous triggers, meaning that you need 10 non-interfering channels that operate totally asynchronously, with very low latency.

Really cannot think of any practical solutions.
The plug-in wires start to seem like a really sexy solution.
##
Thanks, and it's funny you mention the 20-ft charger because I have built one If all goes as planned Manufacturers will get onboard with my contraption in due time
#I'm very optimistic

#### surri

Joined Mar 11, 2019
11
Here's an idea.

Wire short cables from drums to a box containing a microcontroller with 16 digital inputs and a nrf240x tranciever.
The microcontroller constantly polls the wires (<5 us per wire) to see if there's a signal.
When a signal is detected a 4 bit message (max 16 drums) is passed to the nrf240x and sent in shockburst mode.
(https://www.semiconductorstore.com/pdf/NewSite/nordic/WP_nRF240x_ShockBurst.pdf)

Another box near your "brain" with identical hardware will receive the 4 bits and straight away set the outputs according to the packet.

This will def have lower than 10 ms latency. Perhaps around 1-5 ms. But it will take some time and thought to design.

#### Yaakov

Joined Jan 27, 2019
1,612
Here's an idea.

Wire short cables from drums to a box containing a microcontroller with 16 digital inputs and a nrf240x tranciever.
The microcontroller constantly polls the wires (<5 us per wire) to see if there's a signal.
When a signal is detected a 4 bit message (max 16 drums) is passed to the nrf240x and sent in shockburst mode.
(https://www.semiconductorstore.com/pdf/NewSite/nordic/WP_nRF240x_ShockBurst.pdf)

Another box near your "brain" with identical hardware will receive the 4 bits and straight away set the outputs according to the packet.

This will def have lower than 10 ms latency. Perhaps around 1-5 ms. But it will take some time and thought to design.
The signals from the drums are analog, the will require addresses and quite a few bits of amplitude. If you used TDM, it would probably run into the latency wall.

#### surri

Joined Mar 11, 2019
11
The signals from the drums are analog, the will require addresses and quite a few bits of amplitude. If you used TDM, it would probably run into the latency wall.
Aha I thought it was just hit/no hit, is it scaled for "hit intensity"?

#### Yaakov

Joined Jan 27, 2019
1,612
Aha I thought it was just hit/no hit, is it scaled for "hit intensity"?
Drums can be played hard or soft and so the sensors have to reflect that.

#### surri

Joined Mar 11, 2019
11
Drums can be played hard or soft and so the sensors have to reflect that.
Right.

#### djsfantasi

Joined Apr 11, 2010
6,412
The signals from the drums are analog, the will require addresses and quite a few bits of amplitude. If you used TDM, it would probably run into the latency wall.
But what is “quite a few bits”? It’s not like s guitar. It’s a percussion instrument. This is a wild-assed guess, but do you need 255 levels to represent the amplitude? How about 64, 32, 16, or 8?

If your latency estimate is 1-5ms for a four bit address, is it reasonable to extrapolate that eight bits would take 2-10ms? Still within the TS specifications.

So, if sixteen levels of amplitude/ force/ loudness is acceptable, this is still a viable solution. Note that four bits is a “sweet spot”.

So? Are 16 levels of loudness sufficient?

#### Yaakov

Joined Jan 27, 2019
1,612
But what is “quite a few bits”? It’s not like s guitar. It’s a percussion instrument. This is a wild-assed guess, but do you need 255 levels to represent the amplitude? How about 64, 32, 16, or 8?

If your latency estimate is 1-5ms for a four bit address, is it reasonable to extrapolate that eight bits would take 2-10ms? Still within the TS specifications.

So, if sixteen levels of amplitude/ force/ loudness is acceptable, this is still a viable solution. Note that four bits is a “sweet spot”.

So? Are 16 levels of loudness sufficient?
Most do MIDI range, 0-127 values.

#### Yaakov

Joined Jan 27, 2019
1,612
Let me amend that, I say "most" but I was only involved with electronic drum quite a while ago. I am sure they haven't gotten worse, but they may well have gotten better.

#### DickCappels

Joined Aug 21, 2008
6,378
We need a clear description of the signal out of the drumpad in order to proceed.

#### djsfantasi

Joined Apr 11, 2010
6,412
Most do MIDI range, 0-127 values.
Ok then. I agree it is only practical then if the latency of 11 bits is acceptable. Again, It may be practical. If 4 bits take 3ms apiece, the delay for 11ms is less than 9ms.

#### Ryan M

Joined Apr 2, 2019
10
Guys, This is INCREDIBLE feedback! I'm very thankful for the effort ya'll have put into assisting me. (11ms is the teetering point and we'll treat this as the ceiling).

I will do some digging and discover everything I can regarding the signal coming out. Please stand-by anyone who's not burnt out on this yet, and I'll return.

Thanks again! I'm super-excited for this experience !!

til then...

#### Sensacell

Joined Jun 19, 2012
2,567
I think the TS needs each drum /cymbal unit to be it's own separate, independent radio TX unit.

Am I correct?

This makes it harder, you cannot just collect all the signals at one point, process and transmit.
That's what the drum brain does. (I used to have a Roland E-drum set)
The TDMA idea has to be implemented at the radio level.

#### Ryan M

Joined Apr 2, 2019
10
I think the TS needs each drum /cymbal unit to be it's own separate, independent radio TX unit.

Am I correct?

This makes it harder, you cannot just collect all the signals at one point, process and transmit.
That's what the drum brain does. (I used to have a Roland E-drum set)
The TDMA idea has to be implemented at the radio level.
Yes, this is correct. I was initially looking to produce 16 seperate RF transmitters, each with its own receiver plugged into an individual channel at the module. I'm imagining the same technology as a singer who uses a wireless microphone on stage, I just don't need the sound clarity or quality like a singer would, as the devices would be exchanging just small electric impulses. It just needs to pass whatever the signal is that normally travels from one end of the cable to the other end. Praying that I can somehow achieve the greatest cord-cutting project of all time and I realize if it was easy Roland would probably already be selling it in their top kits!

(by the way I had a Roland kit as well, before i got this Alesis and NOTHING compares to those Rolands, amirite? they kick a and it costed like 5 grand; still paying it off lol)

Optimum goal would be to get all 16 channels wireless, but if i can only get 8 to work, then that would cut down half the wire clutter and worth something.

Thanks for the time and effort


text:
# Raycasting from an object to the center of the screen (crosshair) without clipping through objects

Am trying to learn about Raycasting, and I thought I would start with something simple, and that was a laser that would come out of an object (think laser pointer in your hand) and always go to the crosshair.

Using ViewportToWorldPoint I found it easy to cast a ray from the center of the camera, but this had an issue as you can see in this GIF below.

The line would clip through because the ray was coming from the center, not off to the side where the laser pointer would be.

Am not sure how to solve this.

void Update(){
Vector3 ray = Camera.main.ViewportToWorldPoint(new Vector3(0.5f, 0.5f, 0f));

line.SetPosition(0, transform.position);

RaycastHit hit;

if(Physics.Raycast(ray, Camera.main.transform.forward, out hit, raylength)){
if(hit.collider != null){
line.SetPosition(1, hit.point);
}
} else {
Vector3 pos = line.GetPosition(0);
line.SetPosition(1, ray + (Camera.main.transform.forward * raylength));
}
}

The closest thing I could find that I am trying to replicate for this exercise is the No Man's Sky mining tool

You need to fire two rays:

1. The first ray is fired from the player's-eye view, to find out what's under the crosshair, so you know what worldspace point to aim at. The closer that point is, the more you need to angle your shot inward to hit it.

2. The second ray is fired from the tool/weapon muzzle, toward the hit from the first ray. This will tell you what a shot or beam fired from the device will hit first on its way toward the target.

You might also want to use spherecasts for one or both of these checks, if your beam has much thickness or you have a lot of tight corners and gaps to shoot around. This ensures the 0-width ray doesn't miss something that it looks like we should have hit.

Vector3 GetHitPoint(Vector3 muzzlePosition) {
// Unless you've mucked with the projection matrix, firing through
// the center of the screen is the same as firing from the camera itself.
Ray crosshair = new Ray(camera.position, camera.forward);

// Cast a ray forward from the camera to see what's
// under the crosshair from the player's point of view.
Vector3 aimPoint;
RaycastHit hit;
if(Physics.Raycast(crosshair, out hit, rayLength)) {
aimPoint = hit.point;
} else {
aimPoint = crosshair.origin + crosshair.direction * rayLength;
}

// Now we know what to aim at, form a second ray from the tool.
Ray beam = new Ray(muzzlePosition, aimPoint - muzzlePosition);

// If we don't hit anything, just go straight to the aim point.
if(!Physics.Raycast(beam, out hit, rayLength))
return aimPoint;

// Otherwise, stop at whatever we hit on the way.
return hit.point;
}

• I didn't think about using another ray. I assume ray.position is meant to be ray.origin? I tweaked your code and it worked absolutely fine for my exercise. Cheers. – JacketPotatoeFan Apr 12 '19 at 14:41


text:
# zbMATH — the first resource for mathematics

The maximal and minimal ranks of $$A - BXC$$ with applications. (English) Zbl 1036.15004
Maximal and minimal ranks of a linear matrix expression $$A - BXC$$ over an arbitrary field $$\mathbb{F}$$, where $$A \in {\mathbb F}^{m \times n}$$, $$B \in {\mathbb F}^{m \times k}$$ and $$C \in {\mathbb F}^{l \times n}$$, are investigated with regard to a variant matrix $$X \in {\mathbb F}^{k \times l}$$. The obtained results on the extremal ranks of the given linear matrix expression can be used for finding extremal ranks of other linear and nonlinear matrix expressions. The rank invariance and the range invariance of the expression $$A - BXC$$ with respect to its variant matrix $$X$$ is discussed. On the basis of generalized inverses of matrices the general solution to the rank equation $$\text{rank}(A- BXC)+ \text{rank}(BXC)= \text{rank}(A)$$ is presented and the minimal rank of $$A - BXC$$ subject to this equation is obtained.

##### MSC:
 15A03 Vector spaces, linear dependence, rank, lineability 15A09 Theory of matrix inversion and generalized inverses 15A24 Matrix equations and identities
Full Text:


text:
# 1 is what percent of 52.6?

## Please also explain how do do this.

Mar 18, 2017

1.9%

#### Explanation:

$\frac{x}{100} \times 52.6 = 1$

$52.6 x = 100$

$x = \frac{100}{52.6}$

x= 1.9%

ANSWER: 1.9% Rounded to 1 decimal place

Mar 15, 2018

Note that $\approx$ means 'approximately equal to'.

1/52.6~~1.90% rounded to 2 decimal place - approximate value

1/52.6=100/52.6 % exact value

#### Explanation:

Explaining percentage see my solution: https://socratic.org/s/aPdYxYWZ

The value of $\textcolor{g r e e n}{1}$ as a proportion of $\textcolor{red}{52.6}$ is color(white)("dd")color(green)(1)/(color(red)(52.6)

However, if we wish to express this as a percentage we need to change the bottom number (denominator) into 100.

We can change the denominator by doing this: $\textcolor{red}{52.6} \times \frac{100}{52.6} = 100$

However, for multiply or divide, what we do to the bottom of a fraction we have to do to the top.

$\frac{\textcolor{g r e e n}{1} \times \frac{100}{52.6}}{\textcolor{red}{52.6} \times \frac{100}{52.6}} \textcolor{w h i t e}{\text{d") =color(white)("d") (color(green)(1)xx100/52.6)/(color(red)(cancel(52.6))xx100/cancel(52.6)) color(white)("d")= color(white)("d}} \frac{1.901140 \ldots .}{100}$

$= 1.901140 \ldots . \underbrace{\times \frac{1}{100}}$
$\textcolor{w h i t e}{\text{dddddddddddddd}} \downarrow$
=1.901140... color(white)("ddd")% see https://socratic.org/s/aPdYxYWZ

1/52.6~~1.90% rounded to 2 decimal place - approximate value

May 20, 2018

1.9%

#### Explanation:

To find out what percent one quantity is of of another quantity, use the method:

"fraction" xx 100%

We want to know what $\frac{1}{52.6}$ is as a percent.

1/52.6 xx 100%

=1.9%

If you write the fraction as a decimal we have:

$\frac{1}{52.6} = 0.019$

Multiplying by 100% is the same as multiplying by $\frac{100}{100}$, which is the same as multiplying by $1$

It simply changes the decimal form to a percentage.

0019 xx 100%=1.9%


text:
## Probability of sample variance

Hello,

I need help with this exercise. I have the answer but I do not know how to get to that point. Could anybody explain how to solve this problem?

Thanks in advance

We have a random sample of 20 observations. We need to find the lower and upper limits for the ratio of the sample variance divided by the population variance.
The limits are such that the probability that the ratio is below/above the limit is 0,025 (thus 95% will be within the limits).


text:
# 841 search results for "parallel"

## R in the Cloud

December 6, 2012
By

I've been having some great fun parallelizing R code on Amazon's cloud. Now that things are chugging away nicely, it's time to document my foibles so I can remember not to fall into the same pits of despair again. The goal was to perform lots of trails of a randomized statistical simulation. The jobs were independent and fairly chunky, taking...

## ggplot2 0.9.3 and plyr 1.8 have been released!

December 6, 2012
By

We’re pleased to announce new versions of ggplot2 (0.9.3) and plyr (1.8).  To get up and running with the new versions, start a clean R session without ggplot2 or plyr loaded, and run install.packages(c("ggplot2", "gtable", "scales", "plyr")). Read on to find out what’s new. ggplot2 0.9.3 Most of the changes version 0.9.3 are bug fixes. Perhaps

December 5, 2012
By

Far as I remember, today was the first day in my life I succeed to load a text file bigger than 1.5 Gb into R (~ 5 million lines and 18 columns). My computer is not a small stuff, I’m using a Macbook Pro with rough 8GB of RAM, but the issue why I couldn’t

## Big Data Trees with Hadoop HDFS

December 4, 2012
By

Last month's release of Revolution R Enterprise 6.1 added the capability to fit decision and regresson trees on large data sets (using a new parallel external memory algorithm included in the RevoScaleR package). It also introduced the possibility of applying this and the other big-data statistical methods of RevoScaleR to data files distributed in in Hadoop's HDFS file system*,...

## pbdR Updates – Distributed lm.fit() and More

December 3, 2012
By

Over the weekend, we updated all of the pbdR packages currently available on the CRAN.  The updates include tons of internal housecleaning as well as many new features. Notably, pbdBASE_0.1-1 and pbdDMAT_0.1-1 were released, which contain lm.fit() methods.  This function in particular has been available at my github for over a month, but didn't make its way to the...

## forecast package v4.0

December 2, 2012
By

A few days ago I released version 4.0 of the forecast package for R. There were quite a few changes and new features, so I thought it deserved a new version number. I keep a list of changes in the Changelog for the package, but I doubt that many people look at it. So for the record, here are...

## Trading with Support Vector Machines (SVM)

November 30, 2012
By

Finally all the stars have aligned and I can confidently devote some time for back-testing of new trading systems, and Support Vector Machines (SVM) are the new “toy” which is going to keep me busy for a while. SVMs are a well-known tool from the area of supervised Machine Learning, and they are used both

## edply: combining plyr and expand.grid

November 30, 2012
By

Here’s a code snippet I thought I’d share. Very often I find myself checking the output of a function f(a,b) for a lot of different values of a and b, which I then need to plot somehow. An example: here’s a function that computes the value of a sinusoidal function on a grid of points,

## 2012-11 Generating Animation Sequence Descriptions

November 29, 2012
By

This report describes the animaker package for generating descriptions of animation sequences. An animation sequence is composed by combining atomic animations in series to create sequence animations or in parallel to create track animations. Functions are provided for manipulating animation … Continue reading →

## Functional programming with lambda.r

November 20, 2012
By
$Functional programming with lambda.r$

After a four month simmer on various back burners and package conflicts, I’m pleased to announce that the successor to …Continue reading »


text:
# All Science Fair Projects

## Science Fair Project Encyclopedia for Schools!

 Search    Browse    Forum  Coach    Links    Editor    Help    Tell-a-Friend    Encyclopedia    Dictionary

# Science Fair Project Encyclopedia

For information on any area of science that interests you,
enter a keyword (eg. scientific method, molecule, cloud, carbohydrate etc.).
Or else, you can start by choosing any of the categories below.

# Direct sum topology

(Redirected from Disjoint union (topology))

In the mathematical field of topology a direct sum, direct disjoint sum or coproduct is an important universal construction for topological spaces. The canonical topology on the newly constructed space is called direct sum topology.

The dual construction is called topological product.

## Definition

Given two topological spaces (X11) and (X22) we call

$X_1 + X_2 := X_1 \times \lbrace 1 \rbrace \cup X_2 \times \lbrace 2 \rbrace$

the disjunct set union of X1 and X2.

The functions

$i_1: X_1 \to X_1 + X_2$

defined as

$i_1: x_1 \mapsto (x_1,1) \mbox{ , } x_1 \in X_1$

and

$i_2: X_2 \to X_1 + X_2$

defined as

$i_2: x_2 \mapsto (x_2,2) \mbox{ , } x_2 \in X_2$

are called canonical injections.

The direct sum of two topological spaces is defined as

(X11) + (X22): = (X1 + X21 + 2)

with the direct sum topology τ1 + 2 defined as

$O \in \tau_{1+2} \Leftrightarrow i_1^{-1}[O] \in \tau_1 \mbox{ and } i_2^{-1}[O] \in \tau_2 .$

The direct sum topology is the finest topology such that the canonical injections are continuous.


text:
## Custom development for Printer Intercept Software

Hello,

I am interested in getting the following SW made.

1. Intercept all printer commands on a windows desktop.
2. Based on user input, decide whether to simply forward the request to the printer without doing anything OR
3. Extract text information from it and provide APIs to connect to another SW that can use this text and do some useful work.

Please let me know if this SW is already available with you. I need to develop my own SW on top of this solution and so would need the relevant permissions.

Regards,
Customer
---------------------------------------------------------

Thanks for your message, we haven't a software which has this function yet, however, we could develop this function to you based on VeryPDF HookPrinter SDK software, you may download the trial version of VeryPDF HookPrinter SDK software from this web page to try, if you encounter any problem with this software, please feel free to let us know, we are glad to assist you asap,

VeryPDF
---------------------------------------------------------
Hello VeryPDF team,

Thank you for your response. I also have a few questions:

1. What is the technology on which this custom software would be built?
2. I assume that any application calling the printer can be intercepted, please confirm.
3. I assume that this would work with printers from any vendor, please confirm.
4. What would be the rough timelines for such a project?
5. What would be the support model?

Regards,
Customer
---------------------------------------------------------
Thanks for your message, we can develop a custom-build version of HookPrinter software to you, this custom-build version has following features,

1. Support both 32bit and 64bit Windows systems.
2. Support Windows 7, 8, 10, etc. Windows systems.
3. An option to forward the print jobs to original printer or extract text information from printer jobs.
4. Able to hook all printers which installed in your local system.
5. Able to hook all network printers which connected to your system.

>>I also have a few questions:
>>1. What is the technology on which this custom software would be built?

We will hook Windows Spooling System, if an application prints a document to a Windows Printer, the printing process will be controlled by Windows Spooling System, our HookPrinter Layer will get all information from Windows Spooling System, so we could intercept the printing process easily.

>>2. I assume that any application calling the printer can be intercepted, please confirm.

Yes, you are right, any application calling the printer can be intercepted.

>>3. I assume that this would work with printers from any vendor, please confirm.

Yes, as long as a printer is using Windows Spooling system, this printer can be hooked properly.

>>4. What would be the rough timelines for such a project?

In general, we will finish this custom-build software within one week.

>>5. What would be the support model?

We are provide gold support for the software, please look at more information about gold support from this web page,

http://www.verypdf.com/custom/maintenance.htm

VeryPDF
---------------------------------------------------------
Thank you veryPDF team for your quick response.

Some more quick questions:

1. I need to integrate another custom SW that will take the text output from the veryPDF software and do some other operations on the text. For this would it be possible to expose some APIs that allow other applications to be integrated with your software?

2. What would be the language used in your software?

3. You mention that " Yes, as long as a printer is using Windows Spooling system, this printer can be hooked properly.". If the printer is NOT using the windows spooling system (single printer connected to the terminal) can we still install the spooler and connect the veryPDF hook software?
(Apologies I am not very familiar with the printing subsystem)

4. Like I mentioned in my previous email, I would develop some other SW on top of it and the final solution would be deployed in multiple terminals. Are there any limitations/restrictions that I should be aware of?

Regards,
Customer
---------------------------------------------------------
>>Some more quick questions:
>>1. I need to integrate another custom SW that will take the text output
>>from the veryPDF software and do some other operations on the text. For
>>this would it be possible to expose some APIs that allow other applications to be integrated with your software?

Yes, this is possible, you can integrate your software into HookPrinter SDK software by "VeryPDF-HookPrinter.ini" file, "VeryPDF-HookPrinter.ini" file contains following options,

[AutoSave]
; 1 to capture SPL files, 0 will stop to capture SPL files
bCaptureSPLFiles=1

; Your License Key
strLicenseKey=XXXX-XXXX-XXXX-XXXX

; Set the folder to store SPL files
strSPLOutputFolder=D:\downloads\spl

; This is SPL to PDF Converter Command Line application, you can use this command line application to convert from SPL files to PDF files automatically
strCmd=["E:\SPL2PDF\spl2pdf_cmd\spl2pdf.exe" "%1"]

You can write a command line application, set the path of your command line application to "strCmd" option in the "VeryPDF-HookPrinter.ini" file, HookPrinter SDK will call your application after user print a document to a printer, your application will receive the printed SPL file, your application will able to extract text and other information from this SPL file easily.

Please notice, the SPL format is depend on the hooked printer driver, for example,

• If you print a document to a PCL printer, your application will receive a SPL file in PCL format.
• If you print a document to a Postscript printer, your application will receive a SPL file in Postscript format.
• If you print a document to a PDF virtual printer, your application will receive a SPL file in PDF or Postscript format.
• If you print a document to "Microsoft XPS Document Writer" printer, your application will receive a SPL file in XPS format.

VeryPDF has also a "SPL to PDF Converter Command Line" application which can convert from SPL files in SPL, EMF-SPL, Postscript, EPS, XPS, PCL, PXL (PCL-XL), PRN, PDF formats to PDF and other formats, you may download it from this web page for evaluation,

>>2. What would be the language used in your software?

Our software is written in C++, but you can call it from PHP, C#, ASP.NET, VB.NET, etc. program languages easily.

>>3. You mention that "Yes, as long as a printer is using Windows Spooling system, this printer can be hooked properly.". If the printer is NOT using the windows spooling system (single printer connected to the terminal) can we still install the spooler and connect the veryPDF hook software? (Apologies I am not very familiar with the printing subsystem)

In general, 99% printers are based on Windows Spooling System, if you can print a Word document from MS Word to a Windows Printer properly, this Windows Printer will no problem to be hooked.

Some special printers does use COM port to transfer the print data directly, these print data are not go through the spooling system, so our HookPrinter Layer can't receive these print data, for example, for some special barcode printers or invoice printers, these printers are used in special fields and by some special Windows applications only, they are not general printers, I think we can simple ignore these types of printers.

>>4. Like I mentioned in my previous email, I would develop some other SW on top of it and the final solution would be deployed in multiple terminals. Are there any limitations/restrictions that I should be aware of?

After you buy the software, there hasn't any limitations/restrictions for you to use the software, please don't worry about this matter.

VeryPDF

VN:F [1.9.20_1166]
Rating: 0.0/10 (0 votes cast)
VN:F [1.9.20_1166]
Rating: 0 (from 0 votes)
Posted in VeryPDF SDK & COM | | Leave a comment

## Custom software development to intercept all printer commands on a windows desktop, decide whether to simply forward the print jobs to the printer or extract text information from print jobs

Hello,

I am interested in getting the following software made.

1. Intercept all printer commands on a windows desktop.
2. Based on user input, decide whether to simply forward the request to the printer without doing anything OR
3. Extract text information from it and provide APIs to connect to another Software that can use this text and do some useful work.

Please let me know if this software is already available with you. I need to develop my own software on top of this solution and so would need the relevant permissions.

Regards,
Customer
----------------------------------------------
We have some computers on which we charge for printing documents. When a user prints, I would like to intercept the print job, prompt them for their username / password so I can charge their account, then allow the print job to continue through to the printer.

How can this be accomplished? Is it possible to write such a utility in .NET?

Customer
----------------------------------------------
Is there a way to monitor the print queue (before it gets to the print queue) and make sure that a particular user is only printing specified number of copy of a document? I want to find out how many copies of printout particular user had taken to maintain a record of this.

How can i do that using Java Code or any other programing language?

Thanks In Advance.
Customer
----------------------------------------------

Thanks for your message, we haven't a software which has above functions yet, however, we can develop these functions to you based on VeryPDF HookPrinter SDK software, you may download the trial version of VeryPDF HookPrinter SDK software from this web page to try, if you encounter any problem with HookPrinter SDK software, please feel free to let us know, we are glad to assist you asap,

VeryPDF

VN:F [1.9.20_1166]
Rating: 0.0/10 (0 votes cast)
VN:F [1.9.20_1166]
Rating: 0 (from 0 votes)
Posted in VeryPDF SDK & COM | | Leave a comment

## I'm looking for something that can convert MSG (Outlook message) files to PDF using a command prompt

Hello,

I'm looking for something that can convert MSG (Outlook message) files to PDF using a command prompt. Is this something VeryDoc can do?

Thanks,
Customer
-----------------------------------------------

Thanks for your message, "VeryPDF docPrint Pro" and "VeryDOC DOC to Any Converter Command Line" software are all can convert from MSG files to PDF files, you may download "VeryDOC DOC to Any Converter Command Line" software from this web page to try,

after you download it, you can run following command lines to convert from MSG and EML files to PDF files,

doc2any.exe test.msg generate_msg2pdf.pdf

doc2any.exe test.eml generate_eml2pdf.pdf

You can also use following command lines to batch convert all MSG or EML files in a folder to PDF files at one time,

for %F in (D:\downloads\Files\Files\*.msg) do doc2any.exe "%F" "%~dpnF.pdf" >> _report.log

for %F in (D:\downloads\Files\Files\*.eml) do doc2any.exe "%F" "%~dpnF.pdf" >> _report.log

Document Converter (docPrint Pro) can be downloaded from this web page,

after you download and install it, you can run following command lines to convert from MSG files to PDF files,

"C:\Program Files (x86)\docPrint Pro v8.0\doc2pdf.exe" -i D:\test1.msg -o D:\out.pdf

"C:\Program Files (x86)\docPrint Pro v8.0\doc2pdf.exe" -i D:\test2.msg -o D:\out.pdf

You may also look at following web pages for more information about MSG to PDF Conversion,

http://www.verypdf.com/wordpress/201604/how-to-batch-convert-email-files-to-pdf-files-msg-to-pdf-eml-to-pdf-outlook-to-pdf-convert-email-to-pdf-42605.html

http://www.verypdf.com/wordpress/201311/convert-emails-msg-eml-to-htm-txt-pdf-rtf-in-batch-via-command-line-the-easiest-and-fastest-way-to-convert-your-mail-to-pdf-39414.html

http://www.verypdf.com/wordpress/201304/verypdf-eml-to-pdf-converter-command-line-36242.html

http://www.verypdf.com/wordpress/201206/how-to-convert-msg2pdf-28221.html

https://www.verydoc.com/blog/how-to-convert-outlook-msg-files-to-pdf-msg-to-pdf-converter-for-batch-convert-msg-to-pdf.html

VeryPDF

VN:F [1.9.20_1166]
Rating: 0.0/10 (0 votes cast)
VN:F [1.9.20_1166]
Rating: 0 (from 0 votes)
Posted in DOC to Any Converter, docPrint Pro | | Leave a comment

## PDF Print command line is unable to find the printers while printing from a SYSTEM user account on windows server 2016

Dear Verypdf,

We have been using a licensed version of pdfprint command line on a windows server 2012 for several years now. Recently we migrated to a new windows server 2016 and verypdf doesn't seem to find the printers anymore while printing from a SYSTEM user (from a php platform).

http://www.verypdf.com/app/pdf-print-cmd/try-and-buy.html#buy

We have installed and copied all printers in the registry to HK_USERS.

The -listprinter command provides the list of all printers correctly.
Tested with both local and network printers with all possible alias combinations (IP/name/..) all returning the same error message.

The debug log show following:
Reading Command Line options...
Copyright (C) VeryPDF.com
"XXX\pdfprint.exe" "-$" "XXX" "-printer" "XXX" "-debug" "-logtofile" "logloglog.ext" "-pdforient" "1" "-scalex" "100" "-scaley" "100" "XXX\label_test.pdf" Version Build Date: Aug 7 2016 Try to load 'WINSPOOL.DRV' file... Load 'WINSPOOL.DRV' file OK. Current default printer is 'Microsoft Print to PDF'. SetDefaultPrinter to 'XXX' printer, return code = 0. The exec command shows: {"output":"FAIL","cmd":"XXX\\pdfprint.exe -$ XXX -printer \\10.100.X.X\\XXX -debug -logtofile \"logloglog.txt\" -pdforient 1 -scalex 100 -scaley 100 XXX\\label_test.pdf","result":"Can't locate the \"XXX\" printer in this computer, please double check the printer name and to try again."}

Do you maybe have any other suggestions?

Kind regards,
Customer
-----------------------------------------

Thanks for your message, you can use "CmdAsUser Command Line Tool" or "VeryPDFComRunCmd COM Component" to run pdfprint.exe inside an interactive user account instead of default SYSTEM user, you will able to get it work properly.

You may download "CmdAsUser Command Line Tool" or "VeryPDFComRunCmd COM Component" from this web page to try,

You can run following command line to run pdfprint.exe from an interactive user account,

CmdAsUser.exe Administrator . /p password /c "XXX\pdfprint.exe" "-\$" "XXX" "-printer" "XXX" "-debug" "-logtofile" "logloglog.ext" "-pdforient" "1" "-scalex" "100" "-scaley" "100" "XXX\label_test.pdf"

You can also use a COM component to run pdfprint.exe from an interactive user account,

https://www.verydoc.com/exeshell.html#VeryPDFComRunCmd_COM_Component

Please look at following web page for more information,

http://www.verydoc.com/blog/verydoc-release-notes-verydoc-releases-an-exe-com-of-verypdfcomruncmd-exe-today-verypdf-exe-com-does-allow-you-to-call-ms-office-and-any-exe-application-from-asp-php-c-net-etc-program-languag.html

VeryPDF

VN:F [1.9.20_1166]
Rating: 0.0/10 (0 votes cast)
VN:F [1.9.20_1166]
Rating: 0 (from 0 votes)
Posted in PDF Print | Tagged , , | Leave a comment

## PDFPrint SDK and PS to PDF Converter Developer License

Hello, I have a few questions about your technology. We currently use some competing products in our virtual printer, but we’re looking around for some better technology and we’ve been very impressed so far as we test out your stuff.

1. Does the PDFPrint SDK offer any options to send the PDF or PDF raster file DIRECTLY to the printer (port 9100 RAW, LPD, etc.), or must it be submitted to a local, logical printer on the OS?

2. Does the VeryDoc DOCPrint SDK allow us to rebrand the installer and the logical printer? Is there a silent installer available? Can it be set to call an EXE with the resulting PDF instead of popping up a save dialog?

3. Which version of the PS to PDF converter would we need if we wanted to distribute the EXE along with our existing virtual printer and use it silently for conversion?

Looking forward to hearing your answers!
Customer
----------------------------------------

>>1. Does the PDFPrint SDK offer any options to send the PDF or PDF raster file DIRECTLY to the printer (port 9100 RAW, LPD, etc.), or must it be submitted to a local, logical printer on the OS?

Thanks for your message, you can use PDFPrint SDK to print the PDF files or PDF Raster files to local or network printers, however, it can't print the PDF files to Printer Ports (such as LPT1:, LPT2:, etc. ports) directly.

If you wish print the PDF files to Printer Ports directly, you may use following solution to try,

1. You can use VeryDOC PDF to Vector Converter to convert from PDF files to PCL files first, you can download the trial version of VeryDOC PDF to Vector Converter from this web page,

After you download it, you can run following command line to convert your PDF files to PCL files,

pdf2vec.exe C:\in.pdf C:\out.pcl

Please notice, if your Printer Port accepts PS data format only, you need convert from PDF files to PS files,

pdf2vec.exe C:\in.pdf C:\out.ps

2. You can send the converted PCL or PS files to Printer Port directly by following command lines,

copy /b C:\out.pcl LPT1:
copy /b C:\out.ps LPT2:
copy /b C:\out.pcl \\TP123\LaserJet
copy /b C:\out.ps \\TP123\LaserJet
copy /b C:\FILENAME.PRN \\TP123\LaserJet

We hope above solution will useful to you, you may give it a try.

>>2. Does the VeryDoc DOCPrint SDK allow us to rebrand the installer and the logical printer? Is there a silent installer available? Can it be set to call an EXE with the resulting PDF instead of popping up a save dialog?

Thanks for your message, yes, we have OEM License for our products, with the OEM License, we will provide a silent installer to you, we will help you to rebrand the installer and printer's name, such as, with your company name or something else.

We can also assist you to suppress the saving dialog for PDF creation in the OEM License, if you are interest in the OEM License, please feel free to let us know, the exact name that you are interest in, we will provide more information to you asap.

>>3. Which version of the PS to PDF converter would we need if we wanted to distribute the EXE along with our existing virtual printer and use it silently for conversion?

If you wish integrate PS to PDF Converter into your software for redistribution, you will need to purchase the Developer License or OEM License for PS to PDF Converter software.

VeryDOC

VN:F [1.9.20_1166]
Rating: 0.0/10 (0 votes cast)
VN:F [1.9.20_1166]
Rating: 0 (from 0 votes)
Posted in docPrint Pro, PDF Print | Tagged | Leave a comment
Page 5 of 1,434« First...34567...102030...Last »