A local variance based approach to alleviate the scene content interference for source camera identification

Identifying the source camera of images is becoming increasingly important nowadays. A popular approach is to use a type of pattern noise called photo-response non-uniformity (PRNU). The noise of image contains the patterns which can be used as a fingerprint. Despite that, the PRNU-based approach is sensitive towards scene content and image intensity. The identification is poor in areas having low or saturated intensity, or in areas with complicated texture. The reliability of different regions is difficult to model in that it depends on the interaction of scene content and the characteristics of the denoising filter used to extract the noise. In this paper, we showed that the local variance of the noise residual can measure the reliability of the pixel for PRNU-based source camera identification. Hence, we proposed to use local variance to characterize the severeness of the scene content artifacts. The local variance is then incorporated to the general matched filter and peak to correlation energy (PCE) detector to provide an optimal framework for signal detection. The proposed method is tested against several state-of-art methods. The experimental results show that the local variance based approach outperformed other state-of-the-art methods in terms of identification accuracy.     

"Life expectancy" of "ecstasy" tablets in Israel in the years 2001-2003

3,4-Methylenedioxymethamphetamine (MDMA) tablets known as "ecstasy" became a very popular drug amongst Israeli youth in the last decade. The ecstasy tablets have a simple design impressed on them (logos) making it relatively easy to distinguish between various logos. The life expectancy of ecstasy tablet logos, defined as the period between the first seizure by the police of a certain logo until the last seizure of the same logo, was monitored during the years 2001-2003. During this time interval, 58 different tablet logos were seized. A total of 26 logos, defined as common logos with at least 10 independent seizures, were observed. At any given time interval during this period, 8-10 common logos were found with an average life expectancy of approximately 9 months. Five of the observed 26 common logos were defined as the most common logos that appeared in at least 200 independent seizures each. Plots of the number of seizures and number of tablets seized as a function of time are presented and discussed as well as explanations for the high turnover rate of any given logo.     

预算监督体系完善对策研究

预算监督是现代公共财政的重要组成部分,是遏制腐败、增强政府财政透明度的制度条件。目前,我国预算监督体系还存在着不完善的地方,为此,必须以提高人大及其常委会的监督能力和增强审计监督的独立性为要点,构建起立法机关、审计机关和社会力量三重监督相互配合与补充的监督体系。     

Effects of collaborative recall: Denying true information is as powerful as suggesting misinformation

We tested whether someone's ability to tell a good story, in terms of the Reality Monitoring (RM) tool, affects the way s/he judges the stories told by others. Forty participants (undergraduate students) wrote down two statements – one about activities they did 30 minutes ago, and the other about a past event. Subsequently, they rated the quality of a target statement written by someone else. We found that the tendency to provide a not so detailed or a very detailed statement was stable across the two statements the participants wrote. Furthermore, this tendency affected how they judged the target statements: The richer a participant's statements were compared to the target statement, the more critical the participant was in judging the target statement. These findings imply that RM is subject to biases which are related to individual differences. We discuss the implications of these findings for applying the RM lie detection tool in the field.     

基于熵理论的网络舆情系统分析

网络舆情系统是通过自组织使各子系统协同作用从而使系统演化为具有一定有序程度的耗散结构.网络舆情系统熵变揭示了舆情的演变过程,构成舆情系统的四个因素（噪音）决定了熵值大小,也即系统的有序度.因此我们在舆情导控上不但要把握好处理的时间点,同时也要把握好处理的关键点.     

Welfare Reform and Women's Health

SUMMARY

The WCHPC studied the extent of collaboration between state women's health officials and TANF officials with respect to programs that affect the health and well-being of poor women. The kinds and extent of monitoring activities designed to gather information on the health status of this population were also examined. Great unevenness across states was revealed for both collaboration and monitoring. State-level interest in improving both was assessed, barriers to improvement were identified, and recommendations for steps forward were solicited.     

Monitoring School Violence

Abstract

National monitoring of school violence is essential for needs assessments, policymaking, and evaluation at the national level. As informative and important as national monitoring is, the data generated at the national level is often not useful at the district or school site levels. There is therefore a need for a feasible method of monitoring school violence on the district and school level; furthermore, we need to find ways to effectively apply national-level information to schools and school districts. over time should be the foundation for the design, implementation, and evaluation of interventions in this area. In this article, we propose an expanded concept of monitoring that links comparable data on school violence at the grade, school site, district, and national levels. The paper presents our conceptual framework and methodology and illustrates its implementation in a district in Israel. We present examples of reports generated to monitor school violence for the district as a whole and for each of the school sites. Finally, we conclude that this is a feasible and useful model that social services could adopt to monitor practice in many other areas.