A study of mechanisms for improving robotic group performance

Many collaborative multi-robot application domains have limited areas of operation that cause spatial conflicts between robotic teammates. These spatial conflicts can cause the team's productivity to drop with the addition of robots. This phenomenon is impacted by the coordination methods used by the team-members, as different coordination methods yield radically different productivity results. However, selecting the best coordination method to be used by teammates is a formidable task. This paper presents techniques for creating adaptive coordination methods to address this challenge. We first present a combined coordination cost measure, CCC, to quantify the cost of group interactions. Our measure is useful for facilitating comparison between coordination methods, even when multiple cost factors are considered. We consistently find that as CCC values grow, group productivity falls. Using the CCC, we create adaptive coordination techniques that are able to dynamically adjust the efforts spent on coordination to match the number of perceived coordination conflicts in a group. We present two adaptation heuristics that are completely distributed and require no communication between robots. Using these heuristics, robots independently estimate their combined coordination cost (CCC), adjust their coordination methods to minimize it, and increase group productivity. We use simulated robots to perform thousands of experiment trials to demonstrate the efficacy of our approach. We show that using adaptive coordination methods create a statistically significant improvement in productivity over static methods, regardless of the group size.     

入门级消费者的货比三家

TWICE：什么样的特性从消费型数码相机上移到了数码单反上？在入门级市场上表现如何？     

Ionizing radiation and marketing simulation on bioactive compounds and quality of grapefruit (Citrus paradisi c.v. Rio Red)

Bioactive compounds in citrus fruits have been shown to be protective against chronic diseases such as cancer and heart disease, but their levels may be affected by postharvest treatments such as storage and irradiation. In this study, grapefruits were exposed to gamma irradiation at 0, 150 and 300 Gy and then stored at 10 °C for 36 d, followed by an additional 20 d at 20 °C. Flavonoid content, terpenoid content, quality (acidity and total soluble solids) and phenylalanine ammonia-lyase (PAL) activity were evaluated at regular intervals during storage. Irradiation and storage affected (P ? 0.05) the levels of bioactive compounds in grapefruit; however, the effect of storage was prominent. Irradiation differentially affected the flavonoid content of pulp and peel. Fruits exposed to 300 Gy had higher (P ? 0.01) narirutin content in peel compared to control fruits at 12 and 56 d after storage. While storage increased the d-limonene and myrcene content in all treatments, control fruit had higher terpenoid content at the end of the storage. PAL activity was found to be in traces in the peel. In general, irradiation or storage had no considerable effect on total soluble solids; however, acidity decreased (P ? 0.05) with storage.     

Using connectionist models to guide assessment of psycological disorder.

Connectionist models are introduced as promising tools for understanding the nature of psychological disorders and guiding their assessment. Specifically, ways in which connectionist models can guide the following aspects of the assessment process are described: understanding what constructs are relevant to assess, designing approaches to assessing these constructs, and understanding individual differences in data from assessments. Two extended examples are given based on the authors' research on cognitive aspects of depression and Alzheimer's disease. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personality and job performance: Test of the mediating effects of motivation among sales representatives.

Research shows consistent relations between personality and job performance. In this study the authors develop and test a model of job performance that examines the mediating effects of cognitive-motivational work orientations on the relationships between personality traits and performance in a sales job (N=164). Covariance structural analyses revealed proximal motivational variables to be influential mechanisms through which distal personality traits affect job performance. Specifically, striving for status and accomplishment mediate the effects of Extraversion and Conscientiousness on ratings of sales performance. Although Agreeableness was related to striving for communion, neither Agreeableness nor communion striving was related to success in this sales job. The importance of the proposed motivational orientations model is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Shape-driven segmentation of the arterial wall in intravascular ultrasound images

Segmentation of arterial wall boundaries from intravascular images is an important problem for many applications in the study of plaque characteristics, mechanical properties of the arterial wall, its 3-D reconstruction, and its measurements such as lumen size, lumen radius, and wall radius. We present a shape-driven approach to segmentation of the arterial wall from intravascular ultrasound images in the rectangular domain. In a properly built shape space using training data, we constrain the lumen and media-adventitia contours to a smooth, closed geometry, which increases the segmentation quality without any tradeoff with a regularizer term. In addition to a shape prior, we utilize an intensity prior through a nonparametric probability-density-based image energy, with global image measurements rather than pointwise measurements used in previous methods. Furthermore, a detection step is included to address the challenges introduced to the segmentation process by side branches and calcifications. All these features greatly enhance our segmentation method. The tests of our algorithm on a large dataset demonstrate the effectiveness of our approach.     

澳大利亚越野轮胎起重机市场

在澳大利亚资源开发的热潮中．各家起重机租赁公司争先恐后地购买越野轮眙起重机。     

松下演示三维等离子蓝光系统

10月初，在CEATEC上，松下公司展示了“世界上第一个三维全高清等离子影院系统”以及世界上最大的150英寸108019的等离子显示器。