Distributed Query Monitoring through Convex Analysis: Towards Composable Safe Zones

Continuous tracking of complex data analytics queries over high-speed distributed streams is becoming increasingly important. Query tracking can be reduced to continuous monitoring of a condition over the global stream. Communication-efficient monitoring relies on locally processing stream data at the sites where it is generated, by deriving site-local conditions which collectively guarantee the global condition. Recently proposed geometric techniques offer a generic approach for splitting an arbitrary global condition into local geometric monitoring constraints (known as "Safe Zones"); still, their application to various problem domains has so far been based on heuristics and lacking a principled, compositional methodology. In this paper, we present the first known formal results on the difficult problem of effective Safe Zone (SZ) design for complex query monitoring over distributed streams. Exploiting tools from convex analysis, our approach relies on an algebraic representation of SZs which allows us to: (1) Formally define the notion of a "good" SZ for distributed monitoring problems; and, most importantly, (2) Tackle and solve the important problem of systematically composing SZs for monitored conditions expressed as Boolean formulas over simpler conditions (for which SZs are known); furthermore, we prove that, under broad assumptions, the composed SZ is good if the component SZs are good. Our results are, therefore, a first step towards a principled compositional solution to SZ design for distributed query monitoring. Finally, we discuss a number of important applications for our SZ design algorithms, also demonstrating how earlier geometric techniques can be seen as special cases of our framework

Evaluating Maintainability Prejudices with a Large-Scale Study of Open-Source Projects

Exaggeration or context changes can render maintainability experience into prejudice. For example, JavaScript is often seen as least elegant language and hence of lowest maintainability. Such prejudice should not guide decisions without prior empirical validation. We formulated 10 hypotheses about maintainability based on prejudices and test them in a large set of open-source projects (6,897 GitHub repositories, 402 million lines, 5 programming languages). We operationalize maintainability with five static analysis metrics. We found that JavaScript code is not worse than other code, Java code shows higher maintainability than C# code and C code has longer methods than other code. The quality of interface documentation is better in Java code than in other code. Code developed by teams is not of higher and large code bases not of lower maintainability. Projects with high maintainability are not more popular or more often forked. Overall, most hypotheses are not supported by open-source data.Comment: 20 page

Open Source BI Platforms: A Functional and Architectural Comparison

While in the past the BI market was strictly dominated by closed source and commercial tools, the last few years were characterized by the birth of open source solutions: first as single BI tools, and later as complete BI platforms. An Open Source BI platform provides a full spectrum of BI capabilities within a unified system that reduces the overhead for the development and management of each application, and lets the user feel like he/she was using a single BI solution. This paper proposes a comparative evaluation of three different Open Source BI platforms (namely JasperSoft, Pentaho and SpagoBI) aimed at understanding their current features, their future potentialities and their limits when adopted in real projects as well as a basis for research prototyping. Overall we try to understand if the open source phenomenon will be able to become a valid alternative to commercial platforms within the BI context

Spinal cord compression by a solitary metastasis from a low grade leydig cell tumour: a case report and review of the literature

<p>Abstract</p> <p>Background</p> <p>Leydig tumour is rare and there are only three cases with metastatic disease reported.</p> <p>Case presentation</p> <p>A 52 year-old Caucasian male was admitted, on emergency basis to the Orthopaedic Department with six weeks history of increasing midthoracic back pain, change in gait, poor balance, subjective weakness and numbness of the lower trunk and legs. MRI scan showed change in the signal intensity of T4 and T5 vertebral body but their height were maintained. Urgent T4 and T5 corpectomies, decompression of the spinal cord and reconstruction of the vertebral bodies were performed followed by radiotherapy. Neurological status significantly improved with a mild residual numbness over the dorsum of the right foot. The histology of the excised tumour was identical to the primary. At 2 years follow-up visit the patient is neurologically stable and disease free without other organs metastases.</p> <p>Conclusion</p> <p>This is the first case in English literature, which shows that spinal metastases could occur even in the early stage of Leydig cell tumour, without other organs involvement. Aggressive surgical management of spinal metastases combined with post operative radiotherapy can give a better chance for long survivorship.</p

The intra-articular use of ropivacaine for the control of post knee arthroscopy pain

AIMS: The purpose of this prospective randomised study is to evaluate the efficacy, safety and the appropriate dose of the ropivacaine in the control of post-knee arthroscopy pain. METHODS: We randomised 60 patients in two groups to receive 10 ml/7.5 mg/ml ropivacaine (Group B) or 20 ml/7.5 mg/ml (Group A) at the end of a routine knee arthroscopy. We monitored the patient's blood pressure, heart rate, allergic reactions, headache, nausea, we assessed the pain using the visual analogue score at intervals of 1,2,3,4 and 6 hours after the operation. and we recorded the need for extra analgesia. RESULTS: The intraarticular use of the ropivacaine provided excellent control of pain after knee arthroscopy. At two hours post-operatively there wasn't any difference between the two groups. Afterwards, the Group A showed increased pain and need for supplementary medication. CONCLUSION: We believe that intraarticular use of ropivacaine is effective to reduce post-operative pain minimising the use of systematic analgesia

Photo-responsive polymeric structures based on spiropyran

Spiropyrans are one of the most popular classes of photochromic compounds that change their optical and structural properties in response to external inputs such as light, protons and metal ions, making them ideal molecules for the fabrication of multifunctional stimuli-responsive materials. Nowadays, the emphasis in polymeric materials incorporating spiropyran units, focuses on the effectiveness of their reversible response to external photonic stimuli. Photo-control of a range of key characteristics for flow systems, such as wettability, permeability, photo-modulation of flow by photo-actuation of valves, photonic control of uptake and release of guests using films and coatings, and colorimetric sensing of various species, are highlighted and discussed

Integrated Toolset for WSN Application Planning, Development, Commissioning and Maintenance: The WSN-DPCM ARTEMIS-JU Project

In this article we present the main results obtained in the ARTEMIS-JU WSN-DPCM project between October 2011 and September 2015. The first objective of the project was the development of an integrated toolset for Wireless sensor networks (WSN) application planning, development, commissioning and maintenance, which aims to support application domain experts, with limited WSN expertise, to efficiently develop WSN applications from planning to lifetime maintenance. The toolset is made of three main tools: one for planning, one for application development and simulation (which can include hardware nodes), and one for network commissioning and lifetime maintenance. The tools are integrated in a single platform which promotes software reuse by automatically selecting suitable library components for application synthesis and the abstraction of the underlying architecture through the use of a middleware layer. The second objective of the project was to test the effectiveness of the toolset for the development of two case studies in different domains, one for detecting the occupancy state of parking lots and one for monitoring air concentration of harmful gasses near an industrial site

A spatiotemporal Data Envelopment Analysis (S-T DEA) approach:the need to assess evolving units

One of the major challenges in measuring efficiency in terms of resources and outcomes is the assessment of the evolution of units over time. Although Data Envelopment Analysis (DEA) has been applied for time series datasets, DEA models, by construction, form the reference set for inefficient units (lambda values) based on their distance from the efficient frontier, that is, in a spatial manner. However, when dealing with temporal datasets, the proximity in time between units should also be taken into account, since it reflects the structural resemblance among time periods of a unit that evolves. In this paper, we propose a two-stage spatiotemporal DEA approach, which captures both the spatial and temporal dimension through a multi-objective programming model. In the first stage, DEA is solved iteratively extracting for each unit only previous DMUs as peers in its reference set. In the second stage, the lambda values derived from the first stage are fed to a Multiobjective Mixed Integer Linear Programming model, which filters peers in the reference set based on weights assigned to the spatial and temporal dimension. The approach is demonstrated on a real-world example drawn from software development

Is tension band wiring technique the "gold standard" for the treatment of olecranon fractures? A long term functional outcome study

<p>Abstract</p> <p>Background</p> <p>Tension band wiring (TBW) remains the most common operative technique for the internal fixation of olecranon fractures despite the potential occurrence of subjective complaints due to subcutaneous position of the hardware. Aim of this long term retrospective study was to evaluate the elbow function and the patient-rated outcome after TBW fixation of olecranon fractures.</p> <p>Methods</p> <p>We reviewed 62 patients (33 men and 29 women) with an average age of 48.6 years (range, 18–85 years) who underwent TBW osteosynthesis for isolated olecranon fractures. All patients were assessed both clinically with measurement of flexion-extension and pronation-supination arcs and radiologically with elbow X-Rays. Functional outcome was estimated using the Mayo Elbow Performance Score (MEPS), Visual Analogue Scale (VAS) subjective pain score and VAS patient satisfaction score. Follow up: 6–13 years (average 8.2 years).</p> <p>Results</p> <p>There was a higher prevalence of fractures among men until the 5th decade of life and among women in elderly (p = 0.032). Slip or simple fall onto the arm was the main mechanism of injury for 38 fractures (61.3%) while high energy trauma, such as fall from a height (> 2 m) or road accident, was reported in 24 fractures (38.7%). Hardware removal performed in 51 patients (82.3%) but 34 of them (66.6% of removals) were still complaining for mild pain during daily activities. The incidence of pin migration and loosening was not statistically decreased when penetration of the anterior ulnar cortex was accomplished (p = 0.304). Supination was more often affected than pronation (p = 0.027). According to MEPS, 53 patients (85.5%) had a good to excellent result, 6 (9.7%) fair and 3 (4.8%) poor result. The average satisfaction rating was 9.3 out of 10 (range, 6–10) with 31 patients (50%) to remain completely satisfied from the final result. Degenerative changes recorded in 30 elbows (48.4%). However, no correlation could be found between radiographic findings and MEPS (p = 0.073).</p> <p>Conclusion</p> <p>Tension band wiring fixation remains the "gold standard" for the treatment of displaced and minimally comminuted olecranon fractures. In long term, low levels of pain may be evident regardless of whether the metalware is removed and degenerative changes have been developed.</p

Evaluating Process Quality Based on Change Request Data – An Empirical Study of the Eclipse Project

Abstract. The information routinely collected in change request management systems contains valuable information for monitoring of the process quality. However this data is currently utilized in a very limited way. This paper presents an empirical study of the process quality in the product portfolio of the Eclipse project. It is based on a systematic approach for the evaluation of process quality characteristics using change request data. Results of the study offer insights into the development process of Eclipse. Moreover the study allows assessing applicability and limitations of the proposed approach for the evaluation of process quality