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51.
Graph models have long been used in social network analysis and other social and natural sciences to render the analysis of complex systems easier. In applied studies, to understand the behaviour of social networks and the interactions that command that behaviour, it is often necessary to identify sets of elements which form cohesive groups, i.e., groups of actors that are strongly interrelated. The clique concept is a suitable representation for groups of actors that are all directly related pair-wise. However, many social relationships are established not only face-to-face but also through intermediaries, and the clique concept misses all the latter. To deal with these cases, it is necessary to adopt approaches that relax the clique concept. In this paper we introduce a new clique relaxation—the triangle k-club—and its associated maximization problem—the maximum triangle k-club problem. We propose integer programming formulations for the problem, stated in different variable spaces, and derive valid inequalities to strengthen their linear programming relaxations. Computational results on randomly generated and real-world graphs, with \(k=2\) and \(k=3\), are reported. 相似文献
52.
Available literature suggests that sexual self-schemas (i.e., cognitive generalizations about sexual aspects of oneself) influence sexual behavior. Nonetheless, there is a lack of research regarding their role in sexual offending. The aim of the present study was to investigate the relationship between the men's sexual self-schema dimensions (passionate-loving, powerful-aggressive, and open-minded-liberal) and different types of sexual-offending behavior. A total of 50 rapists, 65 child molesters (21 pedophilic, 44 nonpedophilic), and 51 nonsexual offenders answered the Men's Sexual Self-Schema Scale, the Brief Symptom Inventory (BSI), and the Socially Desirable Response Set Measure (SDRS-5). Data were analyzed using multinomial logistic regression, controlling for age, school education, psychological distress, and social desirability. Results showed that rapists as well as nonsexual offenders were more likely to hold the powerful-aggressive sexual self-view compared to pedophilic and nonpedophilic child molesters. Overall, findings seem to be consistent with both a sociocultural component of aggression and the general cognitive profile of offenders. If further research corroborates these preliminary findings, sexual self-concept may be integrated into a comprehensive multifactorial approach of offending behavior. 相似文献
53.
João M. S. Carvalho Paulo Delgado Rami Benbenishty Bilha Davidson-Arad Vânia S. Pinto 《European Journal of Social Work》2018,21(2):296-310
This study aims to analyse professional judgements and decisions made in the Portuguese child care system in face of a case vignette of child maltreatment. Using the approach proposed by Benbenishty et al. [(2015). Decision making in child protection: An international comparative study on maltreatment substantiation, risk assessment and interventions recommendations, and the role of professionals’ child welfare attitudes. Child Abuse & Neglect, 49, 63–75. doi:10.1016/j.chiabu.2015.03.015], we assessed the decisions of professionals, such as to place the child in foster care or reunify her with her family, on the basis of a series of judgements (e.g. substantiation of alleged abuse and neglect, risk assessments) that are influenced by the characteristics of the case, the decision-making context, and mother's and child's wishes. We conclude that there are different approaches to the case based on different professionals' attitudes that can be classified in two groups: one more pro-removal and the other anti-removal. These groups presented different risk assessments and intervention recommendations, and their decisions where significantly influenced by the mother's and child's wishes. Furthermore, we have done comparisons with studies made in other countries, concluding that the country context can be an important factor that leads to different outcomes. Implications for both practice and research are presented. 相似文献
54.
Viscusi W. Kip Carvalho Irineu Antoñanzas Fernando Rovira Joan Braña Francisco J. Portillo Fabiola 《Journal of Risk and Uncertainty》2000,21(2-3):213-234
Using original survey data from Spain, this paper assesses the determinants of smoking behavior. This study examines the effect on smoking of the most diverse set of risk measures ever considered: lung cancer, relative lung cancer risks, lung disease, heart disease, relative heart disease risks, lost life expectancy to smokers, and various risk measures for passive smoking. Smoking measures include cigarette smoking, the number of cigarettes smoked, and pipe and cigar smoking. Primary smoking risks have a more consistent negative effect on smoking than perceived passive smoking risks. 相似文献
55.
Susana Carrapatoso Paula Silva Paulo Colaço Joana Carvalho 《Journal of Housing for the Elderly》2018,32(1):26-38
This study examined the relationship of perceived neighborhood environment factors with recommended volume and intensity of walking in recreational senior walkers. A sample of 85 seniors used an accelerometer and completed the ALPHA questionnaire. Binomial logistic regressions were conducted to detect associations. Perceptions about traffic safety (odds ratio [OR] = 4.395; 95% confidence interval [CI] = 1.024; 18.866) and pleasant environment (OR = 8.718; 95% CI = 1.803; 42.149) were positively related with the achievement of 10,000 steps per day, in older women. The perception of nearby parks was positively associated with the compliance with peak 30-minutes cadence above 100, in older men (OR = 14.353; CI 95% = 1.321; 15.591). No more significant associations were found between perceptions of the neighborhood environment and walking at recommended intensity and volume levels. These results indicated that community initiatives that encourage traffic safety, pleasant environment, and parks may be a promising direction to promote walking at recommended volume and intensity in senior walkers. 相似文献
56.
The concepts developed by resilience engineering allow the understanding and monitoring the functioning of organizations and, particularly, to map the role of human activities, in success or in failure, enabling a better comprehension about how people make decisions in unexpected situations. The capture of information about human activities in the various organization levels gives managers a deeper real-time understanding of what is influencing the people performance, providing awareness of the factors that influence positively or negatively the organizational goals initially projected. The monitoring is important because the correct functioning of complex systems depends on the knowledge that people have to perform their activities and how the system environment provides tools that actually support the human performance. Therefore, organizations should look forward through precursors in operating signals to identify possible problems or solutions in the structure of tasks and activities, safety, quality, schedule, rework, and maintenance. We apply the concepts of resilience engineering to understand the organization by the analysis of cognitive tasks and activities. The aim is the development of a computerized system to monitor human activities to produce indicators to access system resilience. The validation of the approach was made in a real organization and the results show the successful applicability of the system. Based on findings obtained after the experiment of the system in a real organization, and managers and workers opinions, it was possible to show that the use of system provided an anticipated (real-time) perception about how activities are effectively being performed, allowing managers and workers to make decisions more consistent with daily problems, and also to anticipate solutions to cope with unexpected situations. 相似文献
57.
Analysis of working conditions focusing on biological risk: firefighters in Campo Grande, MS, Brazil
Contrera-Moreno L de Andrade SM Motta-Castro AR Pinto AM Salas FR Stief AC 《Work (Reading, Mass.)》2012,41(Z1):5468-5470
Firefighters are exposed to a wide range of risks, among them, biological risk. The objective was to analyze working conditions of firefighters in the city of Campo Grande, MS, Brazil, focusing on risk conditions of exposure to biological material. Three hundred and seven (307) firefighters were interviewed for data collection and observed for ergonomic job analysis (AET). Results: 63.5% of the firefighters suffered some kind of job related accident with blood or body fluids. Statistically significant association was found between having suffered accidents at work and incomplete use of personal protective equipment (PPE). About AET regarding the biological risks, 57.1% of all patients had blood or secretions, which corresponds in average to 16.0% of the total work time, based on a working day of 24 h. Besides biological risks, other stressing factors were identified: emergency and complexity of decision, high responsibility regarding patients and environment, and conflicts. Health promotion and accident prevention actions must be emphasized as measures to minimize these risks. 相似文献
58.
Amélia Oliveira Carvalho Lúcia Lima Rodrigues Manuel Castelo Branco 《Voluntas: International Journal of Voluntary and Nonprofit Organizations》2017,28(5):2278-2311
The aim of this paper is to examine the influence of Portuguese Foundation’s characteristics on their annual report disclosure practices. Data were collected from 142 Foundations in Portugal, which represents 50.9% of the Portuguese foundational sector. Supported by a Structural Equation Model (SEM), this study evaluates cause–effect relationship between Voluntary Disclosure, Board Structure, Organizations’ Characteristics and the existence of Auditing. Findings reveal that Organizations’ Characteristics influence the forms of Auditing, and on its turn, Auditing has a positive indirect impact on Voluntary Disclosure. Contrary to expectations, Board Structure does not affect Voluntary Disclosure. This paper fills a void in the literature by examining the impact of Foundations’ characteristics on their voluntary disclosure of financial and non-financial information. 相似文献
59.
Magda Carvalho Pires Enrico Antnio Colosimo Guilherme Augusto Veloso Raquel de Souza Borges Ferreira 《Journal of applied statistics》2021,48(5):907
Survival data involving silent events are often subject to interval censoring (the event is known to occur within a time interval) and classification errors if a test with no perfect sensitivity and specificity is applied. Considering the nature of this data plays an important role in estimating the time distribution until the occurrence of the event. In this context, we incorporate validation subsets into the parametric proportional hazard model, and show that this additional data, combined with Bayesian inference, compensate the lack of knowledge about test sensitivity and specificity improving the parameter estimates. The proposed model is evaluated through simulation studies, and Bayesian analysis is conducted within a Gibbs sampling procedure. The posterior estimates obtained under validation subset models present lower bias and standard deviation compared to the scenario with no validation subset or the model that assumes perfect sensitivity and specificity. Finally, we illustrate the usefulness of the new methodology with an analysis of real data about HIV acquisition in female sex workers that have been discussed in the literature. 相似文献
60.
Paulo Delgado João M. S. Carvalho Vânia S. Pinto Joana Oliveira 《Journal of social service research》2017,43(5):533-546
This study investigates the association between the contact of children or young people in care with their family, and the foster care placement evaluation (positive or negative) in Portugal. According to the perspectives of foster carers and service professionals' perceptions regarding children and young people's reactions, during and after the visits, are measured. Utilizing a quantitative approach, two fostering services teams and 140 foster carers completed questionnaires, which had 212 children in common. Results indicated that despite the importance of continued contact, especially for children and their parents, it was not determined to be essential to long-term placement. On one hand, there was the perception that a high percentage of children expressed positive reactions during and after the visit, while on the other hand, this didn't influence the perception of placement success. This study also showed significant differences between foster carers' and the professionals' perceptions on several dimensions of foster care, especially the children's reactions during visits. These differences need to be further analyzed in future research and the outcomes used to help improve contact management. 相似文献