复杂背景下快速移动目标的实时跟踪

提出了适用于跟踪在复杂背景下快速移动目标的实时跟踪系统.利用基于马尔可夫场模型的背景减除算法检测像素变化,以跟踪移动目标.分割掩膜的先验概率用马尔可夫场模型来表示,因此目标跟踪任务即被转化成最大后验问题.实验结果表明,本文算法在简单背景或复杂背景下的离线和在线移动目标跟踪方面均有较好的效果.     

Psychomotor performance during a 28 day head-down tilt with and without lower body negative pressure

Several factors may affect psychomotor performance in space: sensory-motor changes, sleep disturbances, psychological modifications induced by the social isolation and confinement. However, psychomotor performance is difficult to assess. A battery of standardized and computerized tests, so-called "Automated Portable Test System" (APTS) was devised to ascertain the cognitive, perceptive and motor abilities and their possible fluctuations according to environmental effects. Antiorthostatic bedrest, often used to simulate weightlessness, (particularly cardiovascular modifications) also constitutes a situation of social confinement and isolation. During two bedrest experiments (with head-down tilt of -6 degrees) of 28 days each, we intended to assess psychomotor performance of 6 males so as to determine whether: on the one hand, it could be altered by remaining in decubitus; on the other, the Lower Body Negative Pressure sessions, designed to prevent orthostatic intolerance back on Earth, could improve the performance. To accomplish this, part of the APTS tests as well as an automated perceptive attention test were performed. No downgrading of psychomotor performance was observed. On the contrary, the tasks were more accurately performed over time. In order to assess the experimental conditions on the acquisition phase, the learning curves were modelled. A beneficial effect of the LBNP sessions on simple tests involving the visual-motor coordination and attention faculties can only be regarded as a mere trend. Methods used in this experiment are also discussed.     

Assessment of the efficacy of medical countermeasures in space flight

Changes in body fluids, electrolytes, and muscle mass are manifestations of adaptation to space flight and readaptation to the 1-g environment. The purposes of this paper are to review the current knowledge of biomedical responses to short- and long-duration space missions and to assess the efficacy of countermeasures to 1-g conditioning. Exercise protocols, fluid hydration, dietary and potential pharmacologic measures are evaluated, and directions for future research activities are recommended.     

COSMOS自动测量仪

爱丁堡皇家天文台的COSMOS自动测量仪是为现代化的大型施密特望远镜的天文数据测量而设计的测量系统。COSMOS的功能之一是自动地从拍摄到的大量星体图象中分离出星系图象。设在澳大利亚的英国施密特望远镜能拍到南天的23等星。COSMOS对施密特望远镜干板测量后,自动识别出星系图象,这样就能对大量可观测的宇宙天体中的星系分布情况进行研究。