Energy conservation is crucial in wireless ad hoc sensor network design to increase network lifetime. Since communication consumes a major part of the energy used by a sensor node, efficient communication is important. Topology control aims at achieving more efficient communication by dropping links and reducing interference among simultaneous transmissions by adjusting the nodes’ transmission power. Since dropping links make a network more susceptible to node failure, a fundamental problem in wireless sensor networks is to find a communication graph with minimum interference and minimum power assignment aiming at an induced topology that can satisfy fault-tolerant properties. In this paper, we examine and propose linear integer programming formulations and a hybrid meta-heuristic GRASP/VNS (Greedy Randomized Adaptive Search Procedure/Variable Neighborhood Search) to determine the transmission power of each node while maintaining a fault-tolerant network and simultaneously minimize the interference and the total power consumption. Optimal biconnected topologies for moderately sized networks with minimum interference and minimum power are obtained using a commercial solver. We report computational simulations comparing the integer programming formulations and the GRASP/VNS, and evaluate the effectiveness of three meta-heuristics in terms of the tradeoffs between computation time and solution quality. We show that the proposed meta-heuristics are able to find good solutions for sensor networks with up to 400 nodes and that the GRASP/VNS was able to systematically find the best lower bounds and optimal solutions.
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While there is extensive research on how Russian interference – in particular Russian disinformation operation – has played out in different European countries, indications of Russian interference directly targeting EU, its institutions or policies received little attention. This paper argues why there is good reason to assume that the EU, its institutions and its policies are an ideal a target for authoritarian regimes to exploit. It then explores in what ways, if any, Russian disinformation campaigning targeted EU institutions and their policies during the political and electoral campaigns leading up to the European Parliament (EP) elections of May 2019. In this context disinformation campaigning in terms of both network flows and contents (‘narratives’) have been examined, on the basis of a review of various reports identifying Russian interference and disinformation and of analyses of overall disinformation flows in Europe and the use of a database monitoring occurrences of disinformation.
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Most multi‑problem young adults (18–27 years old) have been exposed to childhood maltreatment and/or have been involved in juvenile delinquency and, therefore, could have had Child Protection Service (CPS) interference during childhood. The extent to which their childhood problems persist and evolve into young adult‑ hood may differ substantially among cases. This might indicate heterogeneous profiles of CPS risk factors. These pro‑ files may identify combinations of closely interrelated childhood problems which may warrant specific approaches for problem recognition and intervention in clinical practice. The aim of this study was to retrospectively identify distinct statistical classes based on CPS data of multi‑problem young adults in The Netherlands and to explore whether these classes were related to current psychological dysfunctioning and delinquent behaviour. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/).
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Objectives The aim of this study was to examine the reciprocal association between work–family conflict and depressive complaints over time. Methods Cross-lagged structural equation modeling (SEM) was used and three-wave follow-up data from the Maastricht Cohort Study with six years of follow-up [2416 men and 585 women at T1 (2008)]. Work–family conflict was operationalized by distinguishing both work–home interference and home–work interference, as assessed with two subscales of the Survey Work–Home Interference Nijmegen. Depressive complaints were assessed with a subscale of the Hospital Anxiety and Depression scale. Results The results showed a positive cross-lagged relation between home–work interference and depressive complaints. The results of the χ 2 difference test indicated that the model with cross-lagged reciprocal relationships resulted in a significantly better fit to the data compared to the causal (Δχ 2 (2)=9.89, P=0.001), reversed causation model (Δχ 2 (2)=9.25, P=0.01), and the starting model (Δχ 2 (4)=16.34, P=0.002). For work–home interference and depressive complaints, the starting model with no cross-lagged associations over time had the best fit to the empirical data. Conclusions The findings suggest a reciprocal association between home–work interference and depressive complaints since the concepts appear to affect each other mutually across time. This highlights the importance of targeting modifiable risk factors in the etiology of both home–work interference and depressive complaints when designing preventive measures since the two concepts may potentiate each other over time.
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Objective: In myocardial perfusion single-photon emission computed tomography (SPECT), abdominal activity often interferes with the evaluation of perfusion in the inferior wall, especially after pharmacological stress. In this randomized study, we examined the effect of carbonated water intake versus still water intake on the quality of images obtained during myocardial perfusion images (MPI) studies. Methods: A total of 467 MIBI studies were randomized into a carbonated water group and a water group. The presence of intestinal activity adjacent to the inferior wall was evaluated by two observers. Furthermore, a semiquantitative analysis was performed in the adenosine subgroup,using a count ratio of the inferior myocardial wall and adjacent abdominal activity. Results: The need for repeated SPECT in the adenosine studies was 5.3 % in the carbonated water group versus 19.4 % in the still water group (p = 0.019). The inferior wall-to-abdomen count ratio was significantly higher in the carbonated water group compared to the still water group (2.11 ± 1.00 vs. 1.72 ± 0.73, p\0.001). The effect of carbonated water during rest and after exercise was not significant. Conclusions: This randomized study showed that carbonated water significantly reduced the interference of extra-cardiac activity in adenosine SPECT MPI. Keywords: Extra-cardiac radioactivity, Myocardial SPECT, Image quality enhancement, Carbonated water
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Accumulating evidence suggests that spoken word production requires different amounts of top-down control depending on the prevailing circumstances. For example, during Stroop-like tasks, the interference in response time (RT) is typically larger following congruent trials than following incongruent trials. This effect is called the Gratton effect, and has been taken to reflect top-down control adjustments based on the previous trial type. Such control adjustments have been studied extensively in Stroop and Eriksen flanker tasks (mostly using manual responses), but not in the picture–word interference (PWI) task, which is a workhorse of language production research. In one of the few studies of the Gratton effect in PWI, Van Maanen and Van Rijn (2010) examined the effect in picture naming RTs during dual-task performance. Based on PWI effect differences between dual-task conditions, they argued that the functional locus of the PWI effect differs between post-congruent trials (i.e., locus in perceptual and conceptual encoding) and post-incongruent trials (i.e., locus in word planning). However, the dual-task procedure may have contaminated the results. We therefore performed an electroencephalography (EEG) study on the Gratton effect in a regular PWI task. We observed a PWI effect in the RTs, in the N400 component of the event-related brain potentials, and in the midfrontal theta power, regardless of the previous trial type. Moreover, the RTs, N400, and theta power reflected the Gratton effect. These results provide evidence that the PWI effect arises at the word planning stage following both congruent and incongruent trials, while the amount of top-down control changes depending on the previous trial type.
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By analysing intelligence-gathering reform legislation this article discusses access to justice for communications interception by the intelligence and security services. In the aftermath of the Snowden revelations, sophisticated oversight systems for bulk communications surveillance are being established across the globe. In the Netherlands prior judicial consent and a binding complaint procedure have been established. However, although checks and balances for targeted communications interference have been created, accountability mechanisms are less equipped to effectively remedy indiscriminate interference. Therefore, within the context of mass communications surveillance programs, access to justice for complainants remains a contentious issue.
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Purpose: This paper aims to investigate the relationship between home-to-work spillover, measured as positive and negative home–work interference (HWI) and turnover intentions, as well as the mediating role of perceptions concerning training and development practices. Design/methodology/approach: Data were collected among 418 respondents who were working at two business schools. A confirmative structural equation modeling analysis was conducted for the analysis. Findings: As expected, positive HWI showed negative relationships with turnover intentions, while negative HWI related positively to turnover intentions. Training and development practices mediated the relationship between positive HWI and turnover intentions; the mediation effect was stronger for women than it was for men. Training and development practices did not mediate the relationship between negative HWI and turnover intentions, however. Practical implications: The outcomes suggest that helping employees to balance their work and home lives can be beneficial for employees, as well as for employers in terms of reducing turnover intentions. Originality/value: As contributions, additional insight into the relationship between positive and negative non-work factors and turnover intentions by examining the ways in which both positive as well as negative HWI are related to turnover intentions. Furthermore, the research considers the mediating role played by perceptions concerning human resource (HR) practices, and particularly training and development practices as perceived by the employee, in the relationship between positive and negative HWI and turnover intentions.
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Introduction: Illness Perceptions (IPs) may play a role in the management of persistent low back pain. The mediation and/or moderation effect of IPs on primary outcomes in physiotherapy treatment is unknown. Methods: A multiple single-case experimental design, using a matched care physiotherapy intervention, with three phases (phases A-B-A’) was used including a 3 month follow up (phase A’). Primary outcomes: pain intensity, physical functioning and pain interference in daily life. Analyzes: linear mixed models, adjusted for fear of movement, catastrophizing, avoidance, sombreness and sleep. Results: Nine patients were included by six different primary care physiotherapists. Repeated measures on 196 data points showed that IPs Consequences, Personal control, Identity, Concern and Emotional response had a mediation effect on all three primary outcomes. The IP Personal control acted as a moderator for all primary outcomes, with clinically relevant improvements at 3 month follow up. Conclusion: Our study might indicate that some IPs have a mediating or a moderating effect on the outcome of a matched care physiotherapy treatment. Assessing Personal control at baseline, as a relevant moderator for the outcome prognosis of successful physiotherapy management of persistent low back pain, should be further eplored.
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