Security of multi-agent systems: A case study on comparison shopping

The multi-agent-systems paradigm is becoming more and more popular as a basis for realizing net-based solutions. This development is accompanied by an increasing relevance of security issues. For instance, the potential loss of privacy and other assets is a major concern for, both merchants and customers, in Internet-based commerce and, without being properly addressed, such very legitimate concerns hamper the growth of e-commerce.This article uses a comparison-shopping scenario to introduce a general methodology for formally verifying the security of multi-agent systems. Following the approach of possibilistic information flow security, the flow of information between and within agents is restricted in order to ensure that secrets will not be disclosed to unauthorized meddlers. The security requirements for the overall system are then decomposed into requirements for the individual agents that can be verified independently from each other. Exploiting the modular structure of a multi-agent system considerably reduces the complexity of the overall security analysis. The techniques for decomposing security requirements, for verifying individual agents, and for deriving global security guarantees for the entire system from locally verified properties are all generic in the sense that they apply also to many other systems and security requirements than the ones that appear in the example scenario.     

基于GMM-UBM的说话人确认系统的研究

高斯混合模型(Gaussian Mixture Model,GMM)已经广泛的应用于文本无关的声纹识别系统,本文详细介绍了一个把背景模型(Universal Background Model,UBM)应用到说话人建模中去的说话人确认系统。由于人的声音的生物特征多变性,说话人模型还需要进行自适应技术的改进。最后,实验结果证明了采用自适应技术的GMM-UBM模型的高效性。     

Monkey business: Children’s use of character identity to infer shared properties

Children’s toys provide a rich arena for investigating conceptual flexibility, because they often can be understood as possessing an individual identity at multiple levels of abstraction. For example, many dolls (e.g., Winnie-the-Pooh) and action figures (e.g., Batman) can be construed either as characters from a fictional world or as physical objects in the real world. In two experiments, 72 4- and 5-year-olds took part in a property extension task, the results of which provide evidence of an understanding that (1) two representations of a character share certain properties in virtue of their shared character identity, and this sharing does not stem simply from having the same name, and (2) one representation of a character is more likely to share properties with another representation of the character if the properties were acquired by the character than if they were acquired by the representation. Children’s understanding of a representational object’s abstract character identity thus enabled them to transcend using its unique spatio-temporal history as a sole basis for inferring its idiosyncratic properties.     

Super-Recognisers show an advantage for other race face identification

The accurate identification of an unfamiliar individual from a face photo is a critical factor in several applied situations (e.g., border control). Despite this, matching faces to photographic ID is highly prone to error. In lieu of effective training measures, which could reduce face matching errors, the selection of “super-recognisers” (SRs) provides the most promising route to combat misidentification or fraud. However, to date, super-recognition has been defined and tested using almost exclusively “own-race” face memory and matching tests. Here, across three studies, we test Caucasian participants' performance on own- and other-race face identification tasks (GFMT, MFMT, CFMT+, EFMT, CFMT-Chinese). Our findings show that compared to controls, high-performing typical recognisers (Studies 1 and 2) and SRs (Study 3) show superior performance on both the own- and other-race tests. These findings suggest that recruiting SRs in ethnically diverse applied settings could be advantageous.     

中国中小学生综合幸福感量表的编制研究

幸福是人类社会的终极目标和共同追求。幸福社会基础在民生,关键靠教育,重心在培养学生的幸福感。本研究以中国特色世界视野的马克思主义幸福观为理论基础,在综合借鉴国内外相关研究成果基础上,通过对5029名中小学生的测量,编制了中国文化背景下的中小学生综合幸福感量表。量表由道德幸福感、心理幸福感、学业幸福感、健康幸福感和社会幸福感五大分量表构成,包括17个因子,共113个项目,力争科学、系统、全面反映中小学生的幸福感水平。研究结果表明,该量表具有良好的信效度,可用于测评中国中小学生的综合幸福感发展状况     

Name–picture verification as a control measure for object naming: A task analysis and norms for a large set of pictures

The name–picture verification task is widely used in spoken production studies to control for nonlexical differences between picture sets. In this task a word is presented first and followed, after a pause, by a picture. Participants must then make a speeded decision on whether both word and picture refer to the same object. Using regression analyses, we systematically explored the characteristics of this task by assessing the independent contribution of a series of factors that have been found relevant for picture naming in previous studies. We found that, for “match” responses, both visual and conceptual factors played a role, but lexical variables were not significant contributors. No clear pattern emerged from the analysis of “no-match” responses. We interpret these results as validating the use of “match” latencies as control variables in studies or spoken production using picture naming. Norms for match and no-match responses for 396 line drawings taken from Cycowicz, Friedman, Rothstein, and Snodgrass (1997) can be downloaded at: http://language.psy.bris.ac.uk/name-picture_verification.html     

Why employees with higher challenging appraisals style are more affectively engaged at work? The role of challenging stressors: A moderated mediation model

Challenging stressors have been positively linked to various work outcomes. However, the role of individual differences in stress appraisal in shaping the function of challenging stressors and work outcomes has been rarely discussed. Drawing on the individual differences perspective, the authors propose that employees higher in challenge appraisal are more likely to have challenging stressors and are more responsive to such stressors to have a higher positive affect at work. Results obtained from 117 employees supported the hypotheses. The results indicated that challenge appraisal is positively related to challenging stressors. In addition, challenging stressors has a positive association with positive affect at work when challenge appraisal is high but has a null association when challenge appraisal is low. The findings suggest that challenging stressors does not necessarily bring positive work outcomes as suggested in past studies and highlight the importance of considering dispositional tendency in stress appraisal when looking into the function of challenging stressors and work outcomes.     

Young children's understanding of violations of property rights

The present work investigated young children’s normative understanding of property rights using a novel methodology. Two- and 3-year-old children participated in situations in which an actor (1) took possession of an object for himself, and (2) attempted to throw it away. What varied was who owned the object: the actor himself, the child subject, or a third party. We found that while both 2- and 3-year-old children protested frequently when their own object was involved, only 3-year-old children protested more when a third party’s object was involved than when the actor was acting on his own object. This suggests that at the latest around 3 years of age young children begin to understand the normative dimensions of property rights.     

Integrating work and basic values into the Spherical Model of Interests

Two prominent models of values, one in work and the other in life, were examined as they each related to the dimensions underlying the Spherical Model of Interests (Tracey & Rounds, 1996) as measured by the Personal Globe Inventory (PGI; Tracey, 2002). The technique of external property vector fitting was utilized to plot the value constructs onto two- and three-dimensional interest structures in a sample of 206 college students. Results, when compared across both theoretical and empirical definitions of interest space, indicated that all work values and fewer basic values related to two dimensions, but that only the work value of Achievement and the life value of Power related to the Prestige dimension. Implications for research and for assessment that involves integrating the results of values and interest inventories are discussed.