Middle-Out Reasoning for Logic Program Synthesis

We propose a novel approach to automating the synthesis of logic programs: Logic programs are synthesized as a by-product of the planning of a verification proof. The approach is a two-level one: At the object level, we prove program verification conjectures in a sorted, first-order theory. The conjectures are of the form 8args \Gamma\Gamma\Gamma\Gamma! : prog(args \Gamma\Gamma\Gamma\Gamma! ) $ spec(args \Gamma\Gamma\Gamma\Gamma! ). At the meta-level, we plan the object-level verification with an unspecified program definition. The definition is represented with a (second-order) meta-level variable, which becomes instantiated in the course of the planning

Labour Market and Social Policy in Italy: Challenges and Changes. Bertelsmann Policy Brief #2016/02

vEight years after the outbreak of the financial crisis, Italy has still to cope with and overcome a plethora of economic and social challenges. On top of this, it faces an unfavourable demographic structure and severe disparities between its northern and southern regions. Some promising reforms have recently been enacted, specifically targeting poverty and social exclusion. However, much more remains to be done on the way towards greater economic stability and widely shared prosperity

3D modelling of grain size distribution in Quaternary deltaic deposits (Llobregat Delta, NE Spain)

The Llobregat delta constitutes a Pliocene-Quaternary sequence recording progradation. An 8 meter-thick, delta-plain succession temporarily accessible in the subaerial delta plain was sub-divided into four units (A to D), which constitute a shallowing upwards sequence recording sedimentation from shoreface at the bottom (Unit A) to lacustrine settings at the top (Unit D). Unit B basically comprises gravelly, coarse-grained sandy lenticular bodies (up to 20 m wide, up to a few decimetres thick), within a homogenous, medium-grained sandy background, interpreted as prograding foreshore bars. 3D facies models, built by using the sequential conditional indicator simulation method, reproduced the sedimentary heterogeneities identified in Unit B, using as input data the sedimentary body geometry and its correlation with sandstone grain size values, with the grain size modes taken as a continuous, quantitative proxy for facies distribution. The simulations not only reproduced satisfactorily the significant sedimentary heterogeneities generated by the facies arrangement, but also predicted and described the spatial relation and the three-dimensional shape of sedimentary bodies accurately. Quality of the models should be ensured by a consistent prior analysis of the spatial structure of the grain size mode based on semivariogram models

Middle-out reasoning for logic program synthesis

Logic programs can be synthesized as a by-product of the planning of their verification proofs. This is achieved by using higher-order variables at the proof planning level, which become instantiated in the course of planning. We illustrate two uses of such variables in proof planning for program synthesis, one for synthesis proper and one for the selection of induction schemes. We demonstrate that the use of these variables can be restricted naturally in such a way that terms containing them form a tractable extension of first-order terms

Monitoring Time Intervals

Run-time checking of timed properties requires to monitor events occurring within a specified time interval. In a distributed setting, working with intervals is complicated due to uncertainties about network delays and clock synchronization. Determining that an interval can be closed - i.e., that all events occurring within the interval have been observed - cannot be done without a delay. In this paper, we consider how an appropriate delay can be determined based on parameters of a monitoring setup, such as network delay, clock skew and clock rate. We then propose a generic scheme for monitoring time intervals, parameterized by the detection delay, and discuss the use of this monitoring scheme to check different timed specifications, including real-time temporal logics and rate calculations

Evolving Discourses on Water Resource Management and Climate Change in the Equatorial Nile Basin

Transboundary water resources management in the Equatorial Nile Basin (EQNB) is a politically contested issue. There is a growing body of literature examining water-related discourses which identifies the ability of powerful actors and institutions to influence policy. Concern about the effects of future climate change has featured strongly in research on the Nile River for several decades. It is therefore timely to consider whether and how these concerns are reflected in regional policy documents and policy discourse. This study analyzes discourse framings of water resources management and climate change in policy documents (27, published between 2001 and 2013) and as elicited in interviews (38) with water managers in the EQNB. Three main discursive framings are identified which are present in the discourses on both subjects: a problem-oriented environmental risk frame and two solution-oriented frames, on governance and infrastructure development. Climate change discourse only emerges as a common topic around 2007. The framings found in the water resources management discourse and the climate change discourse are almost identical, suggesting that discursive framings were adopted from the former for use in the latter. We infer that the climate change discourse may have offered a less politically sensitive route to circumvent political sensitivities around water allocation and distribution between riparian countries in the EQNB. However, the climate change discourse does not offer a lasting solution to the more fundamental political dispute over water allocation. Moreover, in cases where the climate change discourse is subsumed within a water resources management discourse, there are dangers that it will not fully address the needs of effective adaptation

A foundation for runtime monitoring

Runtime Verification is a lightweight technique that complements other verification methods in an effort to ensure software correctness. The technique poses novel questions to software engineers: it is not easy to identify which specifications are amenable to runtime monitor-ing, nor is it clear which monitors effect the required runtime analysis correctly. This exposition targets a foundational understanding of these questions. Particularly, it considers an expressive specification logic (a syntactic variant of the modal μ-calculus) that is agnostic of the verification method used, together with an elemental framework providing an operational semantics for the runtime analysis performed by monitors. The correspondence between the property satisfactions in the logic on the one hand, and the verdicts reached by the monitors performing the analysis on the other, is a central theme of the study. Such a correspondence underpins the concept of monitorability, used to identify the subsets of the logic that can be adequately monitored for by RV. Another theme of the study is that of understanding what should be expected of a monitor in order for the verification process to be correct. We show how the monitor framework considered can constitute a basis whereby various notions of monitor correctness may be defined and investigated.peer-reviewe

MCMAS: an open-source model checker for the verification of multi-agent systems

We present MCMAS, a model checker for the verification of multi-agent systems. MCMAS supports efficient symbolic techniques for the verification of multi-agent systems against specifications representing temporal, epistemic and strategic properties. We present the underlying semantics of the specification language supported and the algorithms implemented in MCMAS, including its fairness and counterexample generation features. We provide a detailed description of the implementation. We illustrate its use by discussing a number of examples and evaluate its performance by comparing it against other model checkers for multi-agent systems on a common case study

A Foundation for Runtime Monitoring

Runtime Verification is a lightweight technique that complements other verification methods in an effort to ensure software correctness. The technique poses novel questions to software engineers: it is not easy to identify which specifications are amenable to runtime monitoring, nor is it clear which monitors effect the required runtime analysis correctly. This exposition targets a foundational understanding of these questions. Particularly, it considers an expressive specification logic (a syntactic variant of the mmucalc) that is agnostic of the verification method used, together with an elemental framework providing an operational semantics for the runtime analysis performed by monitors. The correspondence between the property satisfactions in the logic on the one hand, and the verdicts reached by the monitors performing the analysis on the other, is a central theme of the study. Such a correspondence underpins the concept of monitorability, used to identify the subsets of the logic that can be adequately monitored for by RV. Another theme of the study is that of understanding what should be expected of a monitor in order for the verification process to be correct. We show how the monitor framework considered can constitute a basis whereby various notions of monitor correctness may be defined and investigated

Иммуноопосредованная саркоидозо-подобная реакция на фоне терапии ингибиторами контрольных точек

Immune checkpoint inhibitors are associated with a wide spectrum of immune-related adverse events (AE) of different severity. Immune-related sarcoidosis-like reactions are relatively rare but clinically important AEs. These abnormalities, due to the appearance of active pathological lymph nodes or nodules in other organs on radiographs, can be falsely interpreted as tumor progression or stabilization and thus affect treatment strategy, leading to unreasonably early therapy discontinuation or its unnecessary continuation. So far there were no convincing criteria for differentiation between sarcoidosis-like reaction and sarcoidosis, oncologist should be aware of this reaction and include it in the differential diagnosis in patient with suspected disease progression who are treated with immune checkpoint inhibitors.Применение терапии ингибиторами контрольных точек может сопровождаться развитием иммуноопосредованных осложнений самого различного спектра и степени тяжести. Одним из достаточно редких, но важных по клинической сути, являются иммуноопосредованные саркоидозо-подобные реакции. Данные изменения, за счет рентгенографического появления активных измененных лимфатических узлов или узелков в иных органах, могут быть ложно трактованы как прогрессирование или стабилизация основного онкологического заболевания и, таким образом, повлиять на тактику лечения, приводя к необоснованно ранней отмене терапии или её ненужному продолжению. Ввиду отсутствия на настоящий момент убедительных критериев отличия саркоидозо-подобной реакции и саркоидоза, необходима осведомленность онкологов о возможности подобной реакции для включения ее в дифференциальный диагноз при подозрениях на прогрессирование у пациентов, получающих иммунотерапию ингибиторами контрольных точек