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141.
Shape and motion from image streams under orthography: a factorization method   总被引:56,自引:18,他引:56  
Inferring scene geometry and camera motion from a stream of images is possible in principle, but is an ill-conditioned problem when the objects are distant with respect to their size. We have developed a factorization method that can overcome this difficulty by recovering shape and motion under orthography without computing depth as an intermediate step.An image stream can be represented by the 2F×P measurement matrix of the image coordinates of P points tracked through F frames. We show that under orthographic projection this matrix is of rank 3.Based on this observation, the factorization method uses the singular-value decomposition technique to factor the measurement matrix into two matrices which represent object shape and camera rotation respectively. Two of the three translation components are computed in a preprocessing stage. The method can also handle and obtain a full solution from a partially filled-in measurement matrix that may result from occlusions or tracking failures.The method gives accurate results, and does not introduce smoothing in either shape or motion. We demonstrate this with a series of experiments on laboratory and outdoor image streams, with and without occlusions.  相似文献   
142.
A gas-chromatographic procedure has been used for the determination of CN- in coke-oven water and in coke-oven waste effluent into the sea. It is based on the treatment of the sample with bromine water and on the direct selective detection of CNBr by gas-solid chromatography. The procedure avoids the preliminary treatments of the sample described in the “Standard Methods” (APHA, 1971) being much faster and more reliable than the previously suggested method.  相似文献   
143.
达涅利戴维·迪斯汀顿是达涅利集团中负责板坯连铸机设备设计和供货的一家专业公司,通过与用户密切合作,开发了许多创新设备,如获得专利的INMO结晶器和OPTIMUM最优化扇形段,推出许多先进的连铸技术,如动态轻压下等,极大地促进了连铸技术的发展.正是由于这些先进技术,才有可能使达涅利在近些年来为世界上最先进的连铸板坯生产厂家提供连铸设备,其中包括韩国浦项、德国蒂森克虏伯、中国宝钢和法国阿赛洛米塔尔.介绍了达涅利的这些创新设备和它们在2006年12月份几乎同时试车投产的两家著名钢厂,宝钢(中国)和阿赛洛米塔尔(法国敦克尔克)的使用情况.  相似文献   
144.
达涅利薄板坯连铸连轧设备最新技术成果   总被引:2,自引:0,他引:2  
给出达涅利薄板坯连铸连轧技术的最新应用成果.这些成果表明,达涅利技术不仅用于生产普通钢种,还可用于生产质量要求严格的优质钢种和高附加值产品.由达涅利在尼兹尼.诺夫戈罗德区Vyksa建设1套CRC(连铸连轧)设备.这是在俄罗斯建设的第1套薄板坯连铸连轧设备,也是世界上第1套利用薄板坯连铸连轧工艺路线生产北极高寒地区用API管线钢的生产设备.另外2套设备已在中国唐山钢铁集团有限公司和本溪钢铁集团有限公司进入满负荷生产阶段,前者一直保持着设备生产能力世界纪录,后者则成为中国第一家利用薄板坯连铸连轧工艺生产硅钢的厂家.  相似文献   
145.
Episodic long-term, short-term, and implicit memory were investigated in 79 elderly subjects who fulfilled criteria for the amnestic form of mild cognitive impairment (a-MCI; i.e., by having an idiopathic amnestic disorder with absence of impairment in cognitive areas other than memory and without confounding medical or psychiatric conditions) and who developed Alzheimer's disease (AD) after 2 years as well as in 111 subjects affected by a-MCI who did not develop dementia. Results document a memory profile in a-MCI subjects characterized by preserved short-term and implicit memory and extensive impairment of episodic long-term memory. In virtually all episodic memory indexes examined (learning, forgetting, recognition abilities), a-MCI subjects who converted to AD were more severely impaired than were subjects who did not become demented. This memory profile, which closely resembles that exhibited by amnestic patients with bilateral mesial-temporal lobe lesions, confirms a precocious phase in preclinical AD characterized by selective involvement of mesial-temporal areas and worsening of the memory impairment as atrophic changes progress in hippocampal structures. In this context of pervasive episodic memory impairment, tests assessing the free recall of verbal material following a delay interval demonstrated the greater sensitivity to memory deficits of a-MCI subjects who developed AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
146.
Manual responses can be defined by differing response parameters. Any of them may generate a Simon effect. For all those response parameters, the same implementation of the Simon effect (in terms of subserving mechanism) is assumed. In 3 experiments, subjects had to respond with either fingers or sticks. Temporal properties of the Simon effect changed with response parameters relevant in a task. The Simon effect for manual responses decayed. For stick responses, in which the action goal differed from the anatomical mapping of the acting hand, a sustained Simon effect was observed. However, if the action goal for stick responses was not instrumental for selecting the correct response, the Simon effect decayed. The findings are consistent with the notion of different mechanisms involved in generating a Simon effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
147.
The CIRCE AMS system started operation in March 2005. The measurement of isotopic ratios 14C/12C in samples of archaeological and environmental interest has rapidly attained high precision and accuracy levels in routine operation. The results of the intercomparison campaign in the framework of the VIRI program, as well as the outcome of a statistical analysis of the about 200 control measurements performed with standard samples, have shown the capability of the whole system for high precision measurements (δR/R < 0.3%), allowing systematic investigations in both archaeological and environmental sciences. 26Al AMS has been implemented for the measurement of the astrophysically relevant 25Mg(p,γ)26Al reaction cross section, while a beam line is under construction for the measurement of actinides isotopic ratios.  相似文献   
148.
In Experiment 1, children performed a Simon task after a spatially compatible or incompatible task. Results showed a Simon effect after the spatially compatible task and a reversed Simon effect after the spatially incompatible task. In Experiments 2–5, an identical procedure was adopted with adult participants, who performed the Simon task immediately after, a day after, or a week after the spatial compatibility task. Experiment 6 established a baseline for the Simon effect. Results showed a Simon effect after the spatially compatible task and no Simon effect or a reversed Simon effect after the spatially incompatible task. A modified version of the computational model of M. Zorzi and C. Umiltà (1995) was used to compare possible accounts of the findings. The best account exploits 2 types of short-term-memory links between stimulus and response and their interaction with long-term-memory links. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
149.
Two hundred fifty-six pregnant women who had quit smoking were classified into the precontemplation (PC), contemplation (C), preparation (PA), or action (A) stages of change for postpartum smoking cessation based on a 3-item algorithm assessing personal goals, self-efficacy, and smoking behavior. Logistic regression and event history analyses indicated group differences in return to smoking at 6 weeks and 3, 6, and 12 months postpartum. The percentage of women who returned to postpartum smoking was highest in the precontemplation stage and decreased with each subsequent stage, that is, at 6 weeks 83% of PCs, 64% of Cs, 35% of PAs, and 24% of As had returned to smoking. Results lend support for the stages of change for postpartum smoking abstinence. Stage-based interventions may be developed to assist women in maintaining abstinence postpartum. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
150.
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