Backward conditioning: A new program specialisation technique and its application to program comprehension

This paper introduces backward conditioning. Like forward conditioning (used in conditioned slicing), backward conditioning consists of specialising a program with respect to a condition inserted into the program. However, whereas forward conditioning deletes statements which are not executed when the initial state satisfies the condition, backward conditioning deletes statements which cannot cause execution to enter a state which satisfies the condition. The relationship between backward and forward conditioning is reminiscent of the relationship between backward and forward slicing. Forward conditioning addresses program comprehension questions of the form `what happens if the program starts in a state satisfying condition c?`, whereas backward conditioning addresses questions of the form `what parts of the program could potentially lead to the program arriving in a state satisfying condition c?' The paper illustrates the use of backward conditioning as a program comprehension assistant and presents an algorithm for constructing backward conditioned programs

What about realized returns in reward-based crowdfunding?

Crowdfunding is an alternative form of financing, especially for entrepreneurs in the early-stage development phase. It is well-known that for investors, beyond altruistic motives, material returns play a crucial role, too. A previous study in this field analyzed returns offered by founders and demanded by investors, resp., by means of a data set from kickstarter.com, a leading platform for reward-based crowdfunding. The present paper additionally looks at the realized returns from an ex post view. It does not present new empirical findings, but identifies problems and limitations in this field, and presents some suggestions for future research

General hospital care for people with intellectual disabilities

Purpose – The purpose of this paper is to explore the extent of compliance of commissioners and providers of hospital services in England with their duty under equalities legislation to be aware of patients with intellectual disabilities as a first step to making appropriate provision for their consequent specific needs. Design/methodology/approach – National survey of healthcare commissioners undertaken as part of an annual learning disabilities services audit. Findings – In total, 41.4 per cent of local areas were unable to supply information about numbers of people with intellectual disabilities among those admitted to hospital, 46.7 and 48 per cent, respectively, could not supply this information about out-patient and accident and emergency department attenders. Figures supplied by those able to provide data varied very substantially and overall were so low as to suggest considerable numbers had been missed. Research limitations/implications – The study is testing what local health commissioners are able to find out from hospitals. The authors do not know the accuracy of the data they reported. Practical implications – The study suggests approaching half of healthcare commissioners in England have little or no information about the extent of proper adjustment of hospital care for people with intellectual disability in their area. Their responsibility to assure this has been repeatedly asserted by government. Social implications – The study indicates a need for more work to improve hospital care for people with intellectual disabilities. Originality/value – This was a government sponsored national study to which local healthcare commissioners were expected to contribute

Node coarsening calculi for program slicing

Several approaches to reverse and re-engineering are based upon program slicing. Unfortunately, for large systems, such as those which typically form the subject of reverse engineering activities, the space and time requirements of slicing can be a barrier to successful application. Faced with this problem, several authors have found it helpful to merge control flow graph (CFG) nodes, thereby improving the space and time requirements of standard slicing algorithms. The node-merging process essentially creates a 'coarser' version of the original CFG. The paper introduces a theory for defining control flow graph node coarsening calculi. The theory formalizes properties of interest, when coarsening is used as a precursor to program slicing. The theory is illustrated with a case study of a coarsening calculus, which is proved to have the desired properties of sharpness and consistency

Experimental determination and thermodynamic modelling of phase diagrams for high temperature materials

The phase equilibria of the Ta-Al-Co, and Ti-Fe-Mo systems were investigated and modelled in order to explore their potential as base systems for disordered BCC_A2 (β) matrix - ordered BCC_B2, D03, or L21 (β’) precipitate strengthened alloys. A detailed experimental investigation into the phase equilibria of the Ta-Al-Co system was performed, followed by the production of ternary isothermal sections at temperatures of 1000⁰C and 1150⁰C. This system does not contain a disordered BCC_A2 Ta to ordered BCC intermetallic two phase field. In contrast, recent work has established that the Ti-Fe-Mo system does contain a BCC_A2 + BCC_B2 two phase region, which allows the production of β/β’ precipitate strengthened alloys. CALPHAD assessments were performed, producing thermodynamic databases for these two systems. Models were selected to describe the Gibbs energy of each phase in the systems, which were then fitted to experimental phase diagram, and thermodynamic data, to produce a complete thermodynamic description for each system. Phase diagrams calculated from these databases were in good agreement with those plotted based on experimental data. These ternary CALPHAD databases could potentially be adapted and incorporated into existing alloy databases, in order to improve the accuracy of modelling calculations for alloy design and processing applications

A Denotational Interprocedural Program Slicer

This paper extends a previously developed intraprocedural denotational program slicer to handle procedures. Using the denotational approach, slices can be defined in terms of the abstract syntax of the object language without the need of a control flow graph or similar intermediate structure. The algorithm presented here is capable of correctly handling the interplay between function and procedure calls, side-effects, and short-circuit expression evaluation. The ability to deal with these features is required in reverse engineering of legacy systems, where code often contains side-effects

Evolutionary testing supported by slicing and transformation

Evolutionary testing is a search based approach to the automated generation of systematic test data, in which the search is guided by the test data adequacy criterion. Two problems for evolutionary testing are the large size of the search space and structural impediments in the implementation of the program which inhibit the formulation of a suitable fitness function to guide the search. In this paper we claim that slicing can be used to narrow the search space and transformation can be applied to the problem of structural impediments. The paper presents examples of how these two techniques have been successfully employed to make evolutionary testing both more efficient and more effective

Automatisch oder manuell investieren?: Auswirkungen auf den Entscheidungsprozess von Kapitalgebern im Crowdlending

Mit der Einführung von automatisierten Handelssystemen stehen Investoren vor der Wahl, entweder Investitionen weiterhin manuell durchzuführen oder einen Teil der Entscheidungsgewalt an Computerprogramme abzugeben. Die vorliegende Arbeit widmet sich der Frage, welche Auswirkungen die Nutzung automatisierter Handelssysteme auf den Entscheidungsprozess von Kapitalgebern haben könnten. Als Untersuchungsgegenstand wird dabei die Crowdlending-Plattform Auxmoney herangezogen, die ihren Nutzern seit einigen Jahren die Möglichkeit einer automatisierten Investition anbietet. Die Ergebnisse zeigen, dass aus normativer Sicht keine klare Empfehlung für eine der beiden Vorgehensweisen ausgesprochen werden kann. So weist die manuelle Projektauswahl eine gewisse Anfälligkeit für mentale Heuristiken auf, die unterschiedliche Rationalitätsdefizite zur Folge haben könnten. Die automatische Projektauswahl schränkt den Entscheidungsträger jedoch in seiner Entscheidungsfreiheit ein und berücksichtigt u. U. nicht alle notwendigen Informationen zur Entscheidungsfindung