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411.
We use a regression discontinuity design to study how academic probation affects outcomes and course‐taking behaviors at a large public university in the United States. Consistent with past work, students placed on probation improve their grade point average (GPA) in the subsequent semester. We document that part of this GPA improvement is attributable to strategic course‐taking, and there is significant heterogeneity in these behaviors across race. Non‐minority students placed on probation attempt fewer credits, easier courses, and are more likely to withdraw from courses in the following term. In contrast, underrepresented minorities exhibit few of these behaviors, consistent with past work that suggests black and Hispanic students are less likely to possess helpful institutional knowledge and use available support systems such as academic counseling. (JEL I20, I23)  相似文献   
412.
This study contributes to the general knowledge of the victim–offender overlap by determining whether the phenomenon exists among older adults and whether known correlates of crime and victimization explain the relationship. Cross-sectional survey data from telephone interviews conducted with individuals 60 years and older (N = 2,000) residing in Arizona and Florida are used to estimate confirmatory factor models for both victimization and criminal offending. The results from a series of multivariate regression models show that victimization is associated with criminal offending. While factors such as low self-control, depression, and spending time in commercial drinking establishments partially attenuate the victimization–crime link, the statistically significant relationship persists in a multivariate context. Further testing indicates that the observed findings are robust across measurement and modeling strategies. Coupled with prior research, the results support the argument that the victim–offender overlap exists (and is difficult to explain) over the life course.  相似文献   
413.
In a graph \(G=(V,E)\), a set \(D \subseteq V\) is said to be a dominating set of G if for every vertex \(u\in V{\setminus }D\), there exists a vertex \(v\in D\) such that \(uv\in E\). A secure dominating set of the graph G is a dominating set D of G such that for every \(u\in V{\setminus }D\), there exists a vertex \(v\in D\) such that \(uv\in E\) and \((D{\setminus }\{v\})\cup \{u\}\) is a dominating set of G. Given a graph G and a positive integer k, the secure domination problem is to decide whether G has a secure dominating set of cardinality at most k. The secure domination problem has been shown to be NP-complete for chordal graphs via split graphs and for bipartite graphs. In Liu et al. (in: Proceedings of 27th workshop on combinatorial mathematics and computation theory, 2010), it is asked to find a polynomial time algorithm for computing a minimum secure dominating set in a block graph. In this paper, we answer this by presenting a linear time algorithm to compute a minimum secure dominating set in block graphs. We then strengthen the known NP-completeness of the secure domination problem by showing that the secure domination problem is NP-complete for undirected path graphs and chordal bipartite graphs.  相似文献   
414.
We propose a new typology of paternalistic leadership styles based on how leaders demonstrate authoritarianism and benevolence, the two essential components of this type of leadership. Benevolence-dominant paternalistic leadership refers to leaders' sole dependence on the use of benevolence without their strong assertion of authority, whereas authoritarianism-dominant paternalistic leadership is based mainly on authoritarianism itself; classical paternalistic leadership, which best fits early observations of paternalistic leaders, refers to the salient combination of both leadership components. We used two distinct samples and methods to test this typology and the association with subordinate performance. Across the two studies, a field investigation with Taiwanese military supervisor-subordinate dyads and a hypothetical scenario experiment with U.S. working adults, we found a positive relationship between classical paternalistic leadership and subordinate performance as strong as that between benevolence-dominant paternalistic leadership and performance. Our findings echo the phenomenon that paternalistic leaders tend to combine benevolence with authoritarianism to affect subordinate performance.  相似文献   
415.
This paper studies a new version of the location problem called the mixed center location problem. Let P be a set of n points in the plane. We first consider the mixed 2-center problem, where one of the centers must be in P, and we solve it in \(O(n^2\log n)\) time. Second, we consider the mixed k-center problem, where m of the centers are in P, and we solve it in \(O(n^{m+O(\sqrt{k-m})})\) time. Motivated by two practical constraints, we propose two variations of the problem. Third, we present a 2-approximation algorithm and three heuristics solving the mixed k-center problem (\(k>2\)).  相似文献   
416.
Psychotherapy requires a high qualification which is gained mainly in practical training. Own treatments of mentally ill patients during training requires close-meshed supervision. This also has to meet the highest standards, which require a systematic training as a training supervisor. This article discusses the various aspects that have to be taken into consideration in behavior therapy. Beyond adherence to therapy manuals, extremely complex interaction processes have to be taken into account that cannot be substantiated by the classical behavior therapy. To this extent, supervision appears as a bridge between science and the art of psychotherapy.  相似文献   
417.
Over the past five years the Artificial Intelligence Center at SRI has been developing a new technology to address the problem of automated information management within real- world contexts. The result of this work is a body of techniques for automated reasoning from evidence that we call evidential reasoning. The techniques are based upon the mathematics of belief functions developed by Dempster and Shafer and have been successfully applied to a variety of problems including computer vision, multisensor integration, and intelligence analysis.

We have developed both a formal basis and a framework for implementating automated reasoning systems based upon these techniques. Both the formal and practical approach can be divided into four parts: (1) specifying a set of distinct propositional spaces, (2) specifying the interrelationships among these spaces, (3) representing bodies of evidence as belief distributions, and (4) establishing paths of the bodies for evidence to move through these spaces by means of evidential operations, eventually converging on spaces where the target questions can be answered. These steps specify a means for arguing from multiple bodies of evidence toward a particular (probabilistic) conclusion. Argument construction is the process by which such evidential analyses are constructed and is the analogue of constructing proof trees in a logical context.

This technology features the ability to reason from uncertain, incomplete, and occasionally inaccurate information based upon seven evidential operations: fusion, discounting, translation, projection, summarization, interpretation, and gisting. These operation are theoretically sound but have intuitive appeal as well.

In implementing this formal approach, we have found that evidential arguments can be represented as graphs. To support the construction, modification, and interrogation of evidential arguments, we have developed Gister. Gister provides an interactive, menu-driven, graphical interface that allows these graphical structures to be easily manipulated.

Our goal is to provide effective automated aids to domain experts for argument construction. Gister represents our first attempt at such an aid.  相似文献   

418.
The satisfaction with life scale (SWLS) is a widely accepted and widely used tool for measuring well-being. Although its potential as a cross-cultural index is recognized, an introduction and systematic validation of the Hebrew version is needed. Thus, the purpose of this study is: (1) to describe the process of developing the Hebrew version of the SWLS, and (2) to examine its construct validity as well as its internal consistency. Four hundred and eighty seven working adults completed the following self reported Hebrew language versions of the: (1) SWLS, (2) positive affect and negative affect scales (PANAS), and (3) the self-rated health (SRH) scale. In addition, as way of gathering additional evidence of validity, the SWLS was completed by proxy (i.e., each participant’s life partner or significant other). Confirmatory factor analysis supported a single-factor structure with significant correlations between the SWLS and the rest of the measures—PANAS scores, the SRH scores as well as the SWLS scores as measured by proxy. In addition, item-analysis supports the internal consistency of the scale. The Hebrew version of the SWLS is a valid and reliable scale and can be utilized in the Israeli context.  相似文献   
419.
This study introduces the Satisfaction with Life Scale adapted for Children (SWLS-C) and presents psychometric findings regarding its validation. The SWLS-C was adapted from the Satisfaction with Life Scale (SWLS; Diener et al. 1985), which is one of the most commonly used measures to assess satisfaction with life in adults. Three subject matter experts adapted the SWLS by changing the wording of the item stem and response format in order to make it more understandable for children. A stratified random sample of 1,233 students (48% girls) in grades 4–7 (mean age 11 years and 7 months) provided data on the SWLS-C and measures of optimism, self-concept, self-efficacy, depression, emphatic concern, and perspective taking. The SWLS-C demonstrated a unidimensional factor structure and high internal consistency. Furthermore, differential item functioning and differential scale functioning analyses indicated that the SWLS-C measures satisfaction with life in the same way for different groups of children (i.e., with regard to gender, first language learned at home—English vs. other language(s) than English—and across different grades) at the item and at the scale level. Associations between scores on the SWLS-C and demographic variables were statistically non-significant or of small effect size. In addition, the SWLS-C showed evidence of convergent and discriminant validity in relation to the other measures. Our results indicate that the SWLS-C is a psychometrically sound instrument that demonstrated evidence of construct validity for this age group. Limitations and future directions are discussed.  相似文献   
420.
Few studies have examined male clients who pay for sex with male escorts. In 2012, clients (n = 495) completed an online survey about their most recent hire. Most clients were White/Caucasian (87.7%), HIV negative (89.5%), employed full time (71.1%), single (58.6%), with a mean age of 54. Three-quarters of clients were gay identified, 18% bisexual, and 4% heterosexual. The median rate paid to escorts was $250 per hour with a modal appointment time of 1 to 2 hours (41.6%). Oral sex was common (80% gave, 69% received), 30% reported anal insertive sex, and 34% reported anal receptive sex. In total, few (12%) reported unprotected anal sex. Satisfaction with encounters was high. Receptive unprotected anal intercourse was associated with greater satisfaction in bivariate analyses but not in multivariable analyses. In a multivariable model, having receptive anal sex (whether protected or not) and rating the financial cost of the encounter as “worth it” were significantly associated with greater satisfaction. This study contributes to a scarce literature regarding clients of male sex workers and, in particular, provides information on the characteristics of men hiring men for sexual services, behavioral event-level data about their encounters, and analysis of factors directly associated with client satisfaction.  相似文献   
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