A WSDL-Based Type System for WS-BPEL

We tackle the problem of providing rigorous formal foundations to current software engineering technologies for web services. We focus on two of the most used XML-based languages for web services: WSDL and WS-BPEL. To this aim, first we select an expressive subset of WS-BPEL, with special concern for modeling the interactions among web service instances in a network context, and define its operational semantics. We call ws-calculus the resulting formalism. Then, we put forward a rigorous typing discipline that formalizes the relationship existing between ws-calculus terms and the associated WSDL documents and supports verification of their compliance. We prove that the type system and the operational semantics of ws-calculus are ‘sound’ and apply our approach to an example application involving three interacting web services

COWS: A Timed Service-Oriented Calculus

COWS (Calculus for Orchestration of Web Services) is a foundational language for Service Oriented Computing that combines in an original way a number of ingredients borrowed from well-known process calculi, e.g. asynchronous communication, polyadic synchronization, pattern matching, protection, delimited receiving and killing activities, while resulting different from any of them. In this paper, we extend COWS with timed orchestration constructs, this way we obtain a language capable of completely formalizing the semantics of WS-BPEL, the ‘de facto’ standard language for orchestration of web services. We present the semantics of the extended language and illustrate its peculiarities and expressiveness by means of several examples

Corporate Governance Research in the Wake of a Systemic Crisis: Lessons and Opportunities from the COVID-19 Pandemic

The Covid-19 pandemic offers an unprecedented opportunity to advance research on how various corporate governance mechanisms shape firms\u2019 decision-making, survival and success. In the short term, corporate governance research could pinpoint which mechanisms in place before the pandemic (e.g., ownership structure, board attributes, executive compensation) will shape corporate responses, thus affecting firms\u2019 survival in the post-pandemic period. In the long term, the crisis will trigger structural changes in governance mechanisms to enable firms to either prevent or respond to the occurrences of potentially similar events. In the reminder of this essay, we will first discuss the peculiar nature of the recent crisis in relation to other recent crises. Then, we will analyse the impact of Covid-19 on five key areas in the field of corporate governance (i.e., corporate purpose, ownership structure, board of directors, executive compensation and accountability) and, for each of them, we will suggest a series of research questions that contribute to redirecting and advancing the domain

Hermitian matrices of three parameters: Perturbing coalescing eigenvalues and a numerical method

In this work we consider Hermitian matrix-valued functions of 3 (real) parameters, and are interested in generic coalescing points of eigenvalues, conical intersections. Unlike our previous works [L. Dieci, A. Papini and A. Pugliese, Approximating coalescing points for eigenvalues of Hermitian matrices of three parameters, SIAM J. Matrix Anal. Appl., 2013] and [L. Dieci and A. Pugliese, Hermitian matrices depending on three parameters: Coalescing eigenvalues, Linear Algebra Appl., 2012], where we worked directly with the Hermitian problem and monitored variation of the geometric phase to detect conical intersections inside a sphere-like region, here we consider the following construction: (i) Associate to the given problem a real symmetric problem, twice the size, all of whose eigenvalues are now (at least) double, (ii) perturb this enlarged problem so that, generically, each pair of consecutive eigenvalues coalesce along curves, and only there, (iii) analyze the structure of these curves, and show that there is a small curve, nearly planar, enclosing the original conical intersection point. We will rigorously justify all of the above steps. Furthermore, we propose and implement an algorithm following the above approach, and illustrate its performance in locating conical intersections

Decompositions and coalescing eigenvalues of symmetric definite pencils depending on parameters

In this work, we consider symmetric positive definite pencils depending on two parameters. That is, we are concerned with the generalized eigenvalue problem $A(x)-\lambda B(x)$, where $A$ and $B$ are symmetric matrix valued functions in ${\mathbb R}^{n\times n}$, smoothly depending on parameters $x\in \Omega\subset {\mathbb R}^2$; further, $B$ is also positive definite. In general, the eigenvalues of this multiparameter problem will not be smooth, the lack of smoothness resulting from eigenvalues being equal at some parameter values (conical intersections). We first give general theoretical results on the smoothness of eigenvalues and eigenvectors for the present generalized eigenvalue problem, and hence for the corresponding projections, and then perform a numerical study of the statistical properties of coalescing eigenvalues for pencils where $A$ and $B$ are either full or banded, for several bandwidths. Our numerical study will be performed with respect to a random matrix ensemble which respects the underlying engineering problems motivating our study.Comment: 34 pages, 4 figure

A note on the Kuramoto-Sivashinsky equation with discontinuity

In this work we consider differential equations of the type $$pm, u^{(k)}=f(u),$$ and study the extinction profile of their solutions. Emphasis is placed on the special case $-u^{(4)}=sign(u)$, which is related to the Kuramoto-Sivashinsky equation. In this case we describe in more detail the extinction phenomenon and prove a conjecture by Galaktionov and Svirshchevskii

Blow-up profile for solutions of a fourth order nonlinear equation

It is well known that the nontrivial solutions of the equation u¿(r)+¿u¿(r)+f(u(r))=0u¿(r)+¿u¿(r)+f(u(r))=0 blow up in finite time under suitable hypotheses on the initial data, ¿¿ and ff. These solutions blow up with large oscillations. Knowledge of the blow-up profile of these solutions is of great importance, for instance, in studying the dynamics of suspension bridges. The equation is also commonly referred to as extended Fisher–Kolmogorov equation or Swift–Hohenberg equation. In this paper we provide details of the blow-up profile. The key idea is to relate this blow-up profile to the existence of periodic solutions for an auxiliary equation

Computation of smooth manifolds via rigorous multi-parameter continuation in infinite dimensions

In this paper, we introduce a constructive rigorous numerical method to compute smooth manifolds implicitly defined by infinite-dimensional nonlinear operators. We compute a simplicial triangulation of the manifold using a multi-parameter continuation method on a finite-dimensional projection. The triangulation is then used to construct local charts and an atlas of the manifold in the infinite-dimensional domain of the operator. The idea behind the construction of the smooth charts is to use the radii polynomial approach to verify the hypotheses of the uniform contraction principle over a simplex. The construction of the manifold is globalized by proving smoothness along the edge of adjacent simplices. We apply the method to compute portions of a two-dimensional manifold of equilibria of the Cahn–Hilliard equation

Update on the management of inflammatory bowel disease: specific role of adalimumab

Anti-tumor necrosis factor alpha (TNF-α) medications are a class of biologics employed in the treatment of patients with inflammatory bowel disease (IBD). Adalimumab is the first fully human monoclonal immunoglobulin directed against TNF-α, which binds with high affinity and specificity to membrane and soluble TNF. Adalimumab administered subcutaneously has demonstrated efficacy in the treatment of rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and severe chronic psoriasis. Studies have shown that adalimumab is effective for inducing and maintaining remission of moderate-to-severe active Crohn’s disease (CD) patients at an induction dose of 160/80 mg (week 0 and 2) and at a maintenance dose of 40 mg every other week. The efficacy of adalimumab as a second-line therapy has also been documented for patients with loss of response or intolerance to infliximab. Adalimumab is also superior to placebo for inducing and maintaining complete perianal fistula closure. It also seems effective for reducing extraintestinal manifestations. The safety profile is similar to that of other anti-TNF therapy in CD patients, with lower immunogenicity and rate of adverse injection reactions than infliximab. Adalimumab is not approved for the treatment of ulcerative colitis (UC). Recently, however, the results of the first randomized, controlled trial on adalimumab for UC showed that adalimumab at 160/80 mg induction dose was safe and effective for inducing remission and clinical response after 8 weeks in patients with moderately-to-severely active UC failing treatment with corticosteroids and/or immunosuppressants. More data are necessary to clarify the therapeutic role of adalimumab in UC. This review of the literature summarizes available data on the efficacy and safety profile adalimumab in patients with IBD

Reply to Dr. Takeuchi: PRES after epidural anesthesia

[No abstract available