Test Suite Generation with the Many Independent Objective (MIO) Algorithm

in Information and Software Technology (2018), 104(December), 195-206

Context: Automatically generating test suites is intrinsically a multi-objective problem, as any of the testing targets (e.g, statements to execute or mutants to kill) is an objective on its own. Test ... [more ▼]

Context: Automatically generating test suites is intrinsically a multi-objective problem, as any of the testing targets (e.g, statements to execute or mutants to kill) is an objective on its own. Test suite generation has peculiarities that are quite different from other more regular optimisation problems. For example, given an existing test suite, one can add more tests to cover the remaining objectives. One would like the smallest number of small tests to cover as many objectives as possible, but that is a secondary goal compared to covering those targets in the first place. Furthermore, the amount of objectives in software testing can quickly become unmanageable, in the order of (tens/hundreds of) thousands, especially for system testing of industrial size systems. Objective: To overcome these issues, different techniques have been proposed, like for example the Whole Test Suite (WTS) approach and the Many-Objective Sorting Algorithm (MOSA). However, those techniques might not scale well to very large numbers of objectives and limited search budgets (a typical case in system testing). In this paper, we propose a novel algorithm, called Many Independent Objective (MIO) algorithm. This algorithm is designed and tailored based on the specific properties of test suite generation. Method: An empirical study was carried out for test suite generation on a series of artificial examples and seven RESTful API web services. The \evo system test generation tool was used, where MIO, MOSA, WTS and random search were compared. Results: The presented MIO algorithm resulted having the best overall performance, but was not the best on all problems. Conclusion: The novel presented MIO algorithm is a step forward in the automation of test suite generation for system testing. However, there are still properties of system testing that can be exploited to achieve even better results. [less ▲]

Islamic banking development and access to credit

in Pacific-Basin Finance Journal (2018), 52

The recent expansion of Islamic banks raises questions on its economic implications. The aim of this paper is to investigate the impact of Islamic banking development on access to credit. We combine data ... [more ▼]

The recent expansion of Islamic banks raises questions on its economic implications. The aim of this paper is to investigate the impact of Islamic banking development on access to credit. We combine data from a unique hand-collected database that covers Islamic banks with firm-level data covering developing and emerging countries over the period of 2006 to 2009. We find that Islamic banking development has overall no impact on credit constraints, while banking development and conventional banking development alleviate obstacles to financing. However Islamic banking development exerts a positive impact on access to credit when conventional banking development is low. Hence we support the view that Islamic banking does not overall alleviate obstacles to financing, but it can act as substitute to conventional banking. [less ▲]

Friend or Foe? Portraying the German Occupier in Luxembourg (1914-1918).

in Mutations. Mémoires et Perspectives du Bassin Minier (2018), (10), 161-167

Physical activity of students in Luxembourg on days with and without physical education and during physical education

Scientific Conference (2018, December)

Phase-field predictive model for setting of fresh self-compacting concrete

in Proceedings in Applied Mathematics and Mechanics (2018), 18(1),

The initial setting of fresh concrete is mainly caused by the dissolution of cement grains and the precipitation of calcium-silicate-hydrates during cement hydration. Progressing hydration drives the ... [more ▼]

The initial setting of fresh concrete is mainly caused by the dissolution of cement grains and the precipitation of calcium-silicate-hydrates during cement hydration. Progressing hydration drives the transition from a dense suspension to a porous solid phase. Fresh mixture of self-compacting concrete (SCC) can be considered as a phase-changing multi-component material and can be described as a continuum at the macro scale, interacting with a set of transport-reaction-diffusion processes which in turn are driven by phenomena at the level of the microstructure. This contribution focuses on a predictive model for the setting of fresh SCC where the liquid-solid phase transition is captured by a phase-field variable using the Ginzburg-Landau type free energy function. Hydration-related chemical reactions together with heat and mass transfer are volume coupled with the mechanical behaviour and determined by the environmental conditions. The weak form of the predictive model is discretised using the finite element method and implemented with the FEniCS computational framework. [less ▲]

Rezension von: Fouquet, Gerhard / Jan Hirschbiegel Sven Rabeler (Hrsg.), Residenzstädte der Vormoderne. Umrisse eines europäischen Phänomens. 1. Symposium des Projekts „Residenzstädte im Alten Reich (1300-1800)“ der Akademie der Wissenschaften zu Göttingen. Kiel, 13.-16. September 2014 (Residenzforschung. Neue Folge: Stadt und Hof, 2), Ostfildern 2016

in Zeitschrift für Historische Forschung (2018), 45(3), 507-509

Web History in Context

in Brügger, Niels; Milligan, Ian (Eds.) The SAGE Handbook of Web History FIRST EDITION (2018)

The presence now of the Web in every area of life demands studies which constitute it simultaneously both as itself a contextualising object and as anchored in a context. Contextualising because today it ... [more ▼]

The presence now of the Web in every area of life demands studies which constitute it simultaneously both as itself a contextualising object and as anchored in a context. Contextualising because today it directly influences an infinite number of objects, which can no longer be studied without taking account of their echoes online. In transmedia dynamics in particular, we can see how the Web is increasingly becoming an ever-present backdrop to controversies, to the configuration of information and even to interpersonal relationships. Equally, the Web must find its own contextualisation, first of all – since we are historians – from a diachronic perspective. The first challenge is not to remain within the limits set by the technology itself. This twofold approach (the Web in context and the Web as context) suggests how focused we need to be on the construction of an ever-changing socio-technical reality – a return to a totalising, process-focused history which takes account of ongoing developments. We should resist the effects of any discourse tending to fix realities or establish, in hieratic or metonymic fashion, an image of ‘THE’ Web. The present analysis falls into three main sections, which interrogate, in turn, the diachronic or temporal contextualisation, the boundaries or spatial contextualisation, and finally collective and individual experiences of the Web. [less ▲]

Closed-Form Solution for Computationally Efficient Symbol-Level Precoding

Scientific Conference (2018, December)

We present a convex optimization based Symbol-Level Precoding (SLP) for sum power minimization and propose the low-latency closed-form algorithm to find a heuristic solution to the optimization problem ... [more ▼]

We present a convex optimization based Symbol-Level Precoding (SLP) for sum power minimization and propose the low-latency closed-form algorithm to find a heuristic solution to the optimization problem. The technique exploits constructive interference at the multi-user MIMO systems and minimizes the sum power of the transmitted precoded signal per each symbol slot. As a result, the received signals gain extra Signal-to-Noise Ratio (SNR), which leads to the improved data rate and energy efficiency. We benchmark the low-complexity algorithm for solving the optimization technique against the conventional Fast Non-Negative Least Squares algorithm (NNLS). The demonstrated design of the SLP technique combined with the proposed closed-form algorithm has low computational complexity and fast processing time, which is applicable in low-latency high-throughput satellite communication systems. [less ▲]

Μυστική παρακολούθηση και το δικαίωμα σεβασμού της ιδιωτικής ζωής - ΕΔΔΑ, Προσφυγές Nos 58170/13 62322/14 24960/15, Υπόθεση Big Brother Watch και λοιποί κατά Ηνωμένου Βασιλείου, απόγαση της 13ης Σεπτεμβρίου 2018

in Hellenic Review of European Law (2018)

Management of Parkinson’s Disease 20 Years from Now: Towards Digital Health Pathways

in Journal of Parkinson's Disease (2018)

[en] Current best medical treatment for patients with Parkinson’s disease (PD) involves a medical professional who applies state-of-the-art knowledge of diagnostics and treatment— as derived from cohort ... [more ▼]

[en] Current best medical treatment for patients with Parkinson’s disease (PD) involves a medical professional who applies state-of-the-art knowledge of diagnostics and treatment— as derived from cohort studies and clinical trials— to the healthcare process of individual patients. Thus, the much-needed personalization of medicine depends on the abilities, experience and intuition of medical professionals to adjust group-based knowledge to individual decision making. Within 20 years from now, such personal clinical decisions will be largely supported by digital means, also defining a new ecosystem of healthcare often referred to as “digital medicine”. We expect that the next phase of digitalization will include new “digital health pathways”: data-driven personalized decision support that is based on a combination of multimodal data sources, including evidence-based medical knowledge (e.g., clinical guidelines), personal disease profiles (including genetic determinants of disease progression and treatment response), insights into individual disease trajectories (thereby defining subgroups of patients) and individual patients’ needs. Here, we illustrate the potential of this development by sketching the contours of a digitally supported care pathway for gait disability and falls. Such digital health pathways will support the introduction of personalized medicine for PD patients, allowing patients to benefit optimally from individually tailored treatments. This should result in a better quality of life for patients and lower costs for society. [less ▲]