Debugging mixed‐environment programs with Blink

Programmers build large‐scale systems with multiple languages to leverage legacy code and languages best suited to their problems. For instance, the same program may use Java for ease of programming and C to interface with the operating system. These programs pose significant debugging challenges, because programmers need to understand and control code across languages, which often execute in different environments. Unfortunately, traditional multilingual debuggers require a single execution environment. This paper presents a novel composition approach to building portable mixed‐environment debuggers, in which an intermediate agent interposes on language transitions, controlling and reusing single‐environment debuggers. We implement debugger composition in Blink, a debugger for Java, C, and the Jeannie programming language. We show that Blink is (i) simple: it requires modest amounts of new code; (ii) portable: it supports multiple Java virtual machines, C compilers, operating systems, and component debuggers; and (iii) powerful: composition eases debugging, while supporting new mixed‐language expression evaluation and Java native interface bug diagnostics. To demonstrate the generality of interposition, we build prototypes and demonstrate debugger language transitions with C for five of six other languages (Caml, Common Lisp, C#, Perl 5, Python, and Ruby) without modifications to their debuggers. Using real‐world case studies, we show that diagnosing language interface errors require prior single‐environment debuggers to restart execution multiple times, whereas Blink directly diagnoses them with one execution. Copyright © 2014 John Wiley & Sons, Ltd.     

Minimal output unstable configurations in chemical reaction networks and deciders

We study the set of output stable configurations of chemical reaction deciders (CRDs). It turns out that CRDs with only bimolecular reactions (which are almost equivalent to population protocols) have a special structure that allows for an algorithm to efficiently compute their finite set of minimal output unstable configurations. As a consequence, a relatively large set of configurations may be efficiently checked for output stability. We also provide a number of observations regarding the semilinearity result of Angluin et al. (Distrib Comput 20(4):279–304, 2007) from the context of population protocols (which is a central result for output stable CRDs). In particular, we observe that the computation-friendly class of totally stable CRDs has equal expressive power as the larger class of output stable CRDs.     

Survey of control performance in quantum information processing

There is a rich variety of physics underlying the fundamental gating operations for quantum information processing (QIP). A key aspect of a QIP system is how noise may enter during quantum operations and how suppressing or correcting its effects can best be addressed. Quantum control techniques have been developed to specifically address this effort, although a detailed classification of the compatibility of controls schemes with noise sources found in common quantum systems has not yet been performed. This work numerically examines the performance of modern control methods for suppressing decoherence in the presence of noise forms found in viable quantum systems. The noise-averaged process matrix for controlled one-qubit and two-qubit operations are calculated across noise found in systems driven by Markovian open quantum dynamics. Rather than aiming to describe the absolute best control scheme for a given physical circumstance, this work serves instead to classify quantum control behavior across a large class of noise forms so that opportunities for improving QIP performance may be identified.     

DB2 Universal Database: A Case Study of a Successful User-Centered Design Program

This case study describes the application of user-centered design (UCD) principles to the development of a complex middleware software product-IBM's DB2(r) Universal Database. Motivated by trade press reviews highlighting ease-of-use problems, a multisite development team utilized IBM UCD to transform ease of use into a featured product attribute. This case study describes the initial application of UCD to DB21 and the positive business results that followed: critical acclaim, increased marketshare and user satisfaction, and increased support and adoption of UCD across the IBM database product family. Although ease-of-use objectives, target markets, and human factors practitioners' roles have evolved over 6 years and multiple versions of the product, DB2 continues to achieve positive results with UCD. In addition to the flexibility of the UCD methodology, other factors that influenced DB2's success included management support, resource commitment, cross-site communication and collaboration, detailed product specifications, and a focus on supporting user tasks.     

Building Trust and Cooperation through Technology Adaptation in Virtual Teams: Empirical Field Evidence

Abstract

This article reports findings of a study of how leaders of virtual information systems development teams improve team trust and cooperation by managing adaptation of information and communications tools. Results indicate how Theory X (command and control) and Theory Y (facilitate and support) styles of leadership enable and hinder effective outcomes.     

Beyond Transactional Systems

Although most organizations realize the need to shift the emphasis in systems development from transactional systems to tactical and strategic systems, they are often reluctant or unable to do so. This column examines the reasons for this and discusses how MIS managers can motivate both users and senior managers to develop these systems.     

STRATEGIC PLANNING The MIS Strategic Planning Process

Abstract

A large portion of the literature about business and information systems is written at the grand, strategic level. That is certainly the case for the first two books reviewed in this column. One deals with the broad implications of the shift of routine IT work to Asia and the potential for this shift to expand into development and concepts. The other presents a framework for ameliorating IT risk. The third book is concerned with the nitty gritty of the little decisions, made over and over, in day-to-day operations. The focus is on ways of improving and automating these decisions to gain strategic advantage. And, as you would expect, this third book is much longer and much more detailed than the first two.     

Disquiet in the plasma

The metaphor of plasma is taken up to present and discuss movement and engagement by participants in mixed reality installation arts. Two works involving full body video portraits exhibited through large plasma screens in a variety of public settings are covered. Machinic mediations of video realism are considered in terms of embodied interaction in which viewer-participants contribute to the ‘disquiet’ of gendered figuring. Processural, proximal and personal aspects of responsive engagement are discussed. This is extended to performativity that may lead us to critical reflection of our own actions and responses in mixed reality arts.     

Digital Intuition: Applying Common Sense Using Dimensionality Reduction

Understanding the world we live in requires access to a large amount of background knowledge: the commonsense knowledge that most people have and most computer systems don't. Many of the limitations of artificial intelligence today relate to the problem of acquiring and understanding common sense. The Open Mind Common Sense project began to collect common sense from volunteers on the Internet starting in 2000. The collected information is converted to a semantic network called ConceptNet. Reducing the dimensionality of ConceptNet's graph structure gives a matrix representation called AnalogySpace, which reveals large-scale patterns in the data, smoothes over noise, and predicts new knowledge. Extending this work, we have created a method that uses singular value decomposition to aid in the integration of systems or representations. This technique, called blending, can be harnessed to find and exploit correlations between different resources, enabling commonsense reasoning over a broader domain.