121 resultados para Obstacle avoidance


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本文根据在第一部分中推导出来的描述资源竞争的着色ROPN给出在柔性制造系统中无死锁运行的充分必要条件,从而得出相应的控制规律。它是一种资源动态分配的策略,它决定当一个资源空闲时,是否可以分配给一个任务,可以的话先分配给谁,以保证系统无死锁,并使得资源利用率最大。

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柔性制造系统的主要特点是多种不同类型的工件同时在系统中加工,这些工件竞争系统的有限资源,导致象系统死锁等这样的不希望事件的发生,本文用一种Petri网模型,称之为着色面向资源的Petri网(着色ROPN)来描述系统中的这一竞争过程;这一模型揭示了资源竞争过程的本质特点,从而为寻求死锁避免的充要条件提供了基础。

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本文研究越野移动机器人驾驶专家系统等有关问题.首先介绍了系统的硬件支持环境,然后阐述了自动驾驶专家系统的总体结构,有关知识库的内容以及使用知识的各功能模块的作用与运行机理.该系统已部分得以应用,能够完全代替驾驶员完成各种驾驶操作,并能进行自主导航、运动规划、自动绕障、动态跟踪目标、原路返回以及示教再现等复杂任务。

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本文研究水下机器人在障碍位置未知条件下,进行路径规划的方法,使自治水下机器人以最短的行程距离,避开障碍,达到预定目标.针对变化的、复杂的海洋情况,本文采用动态与静态相结合、规划与控制相结合的手段,应用人工势场理论,引入距离误差做动态反馈补偿,实现全局规划控制.本文提出的这种适于自治水下机器人导航的动态路径规划-控制方法,可以解决障碍环境参数已知、未知的路径规划问题.仿真结果表明该方法具有较强的稳定性和适应性.

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本文提出的面向任务的机器人语言是为移动机器人提供的一种编程工具。利用环境描述语言和其他灵活的人机对话方式建立环境模型;根据各种不同的性能指标,规划出最佳路径;根据安全等因素自动规划出最佳路径上的行走参数;对来自传感器的信息进行处理,以确定机器人实际位置及障碍情况;引导机器人沿规划好的路径行走,纠正偏差或重新选择避障路径。

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机器人已成为进一步实现制造业、非制造业、军事活动以至家庭服务自动化的重要工具.机器人学则是更综合地研究如何使机器或系统具有“思想、感知或动作功能的一门交叉性新学科”.机器人的发展是波浪式的,经历了多次的曲折.目前工业机器人中除装配机器人外,其他点焊、弧焊、喷漆及搬运机器人,由于应用范围限制,以及工业生产装备更新速度和投资规模的影响,市场日趋饱和.以美国为例.制造商订单1984年达到高峰6046台.至1986年下降至5713台,不过对机器人未来市场大都持乐观态度.但进一步开拓市场.有待于推出适用于各种环境作业的各式各样的机器人.日本东京大学教授认为机器人当前处于又一次高潮的前夜(Nightmare),正是需要大力加强研究开发的时期.我国正在着手建立工业机器人产业,这一情况值得我们注意.本文着重从研究角度来介绍当前机器人及机器人学中的控制问题的现状及主要问题.

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Reflectivity sequences extraction is a key part of impedance inversion in seismic exploration. Although many valid inversion methods exist, with crosswell seismic data, the frequency brand of seismic data can not be broadened to satisfy the practical need. It is an urgent problem to be solved. Pre-stack depth migration which developed in these years becomes more and more robust in the exploration. It is a powerful technology of imaging to the geological object with complex structure and its final result is reflectivity imaging. Based on the reflectivity imaging of crosswell seismic data and wave equation, this paper completed such works as follows: Completes the workflow of blind deconvolution, Cauchy criteria is used to regulate the inversion(sparse inversion). Also the precondition conjugate gradient(PCG) based on Krylov subspace is combined with to decrease the computation, improves the speed, and the transition matrix is not necessary anymore be positive and symmetric. This method is used to the high frequency recovery of crosswell seismic section and the result is satisfactory. Application of rotation transform and viterbi algorithm in the preprocess of equation prestack depth migration. In equation prestack depth migration, the grid of seismic dataset is required to be regular. Due to the influence of complex terrain and fold, the acquisition geometry sometimes becomes irregular. At the same time, to avoid the aliasing produced by the sparse sample along the on-line, interpolation should be done between tracks. In this paper, I use the rotation transform to make on-line run parallel with the coordinate, and also use the viterbi algorithm to complete the automatic picking of events, the result is satisfactory. 1. Imaging is a key part of pre-stack depth migration besides extrapolation. Imaging condition can influence the final result of reflectivity sequences imaging greatly however accurate the extrapolation operator is. The author does migration of Marmousi under different imaging conditions. And analyzes these methods according to the results. The results of computation show that imaging condition which stabilize source wave field and the least-squares estimation imaging condition in this paper are better than the conventional correlation imaging condition. The traditional pattern of "distributed computing and mass decision" is wisely adopted in the field of seismic data processing and becoming an obstacle of the promoting of the enterprise management level. Thus at the end of this paper, a systemic solution scheme, which employs the mode of "distributed computing - centralized storage - instant release", is brought forward, based on the combination of C/S and B/S release models. The architecture of the solution, the corresponding web technology and the client software are introduced. The application shows that the validity of this scheme.

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The aim of this research is to explore the relationships between school avoidance tendency and school stressors, stress response, social support, coping style of secondary school students. Three studies were carried out. School avoidance tendency scale, mental health scale, coping style scale of secondary school students from Japan were revised in the first research. In the second research, the difference in gender, cities, grades of five variables were discussed. In the third research, the relationships of five variables were discussed. A total of 883 students from grade one of middle school to grade 3 of high school in Beijing, Taiyuan and Wulanchabu, completed three scales. Analysis showed that: 1. The main effects of city, gender, and grade were present significantly on School avoidance tendency, and the inter-effects were not significant. The differences were significant between three grades of middle schools, and not significant between three grades of high schools. The high school students were significant than middle school students on school avoidance tendency. 2. The main effect of city was not significant, but gender, and grade were present significantly on stressor, and the inter-effects were not significant. The most stressor was study one, than the relationship stressor from teachers. The relationship stressor from friends was at least. 3. The main effects of city and grade were present significantly on stress responses, but the main effect of gender was not significant, and the inter-effect was not significant. The most stress response was the physical response. 4. The main effects of city and gender, the inter-effect were not present significantly on social supports. The main effect of grade was present significantly. The most social support was from mother, than from friends, father, and the teachers. 5. The differences between cites on coping styles were not significant. Positive coping style was used mostly, than the style of help requirement, cognitive coping style. 6. Stressor and stress responses had significant positive predictive role on school avoidance tendency. Social supports had negative predictive role. Social supports had not moderator role between stressor, stress responses and schools avoidance tendency. Stress responses had a part of mediator between stressor and school avoidance tendency. 7. In the coping styles, positive coping style and help requirement style had negative predictive role, but cognitive coping style had positive predictive role on school avoidance tendency. Coping styles had negative predictive role. Coping styles had not moderator role between stressor, stress responses and school avoidance tendency.

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In the period of college, an individual matures rapidly in all aspects. College engineering students are the important parts of undergraduates. The state of an individual’s mental health may affect and even decide his future life and work. The level of the student’s self-concept and the kind of coping styles the students adopt are directly related to their mental health. So, it is significant to study the psychological stress, coping and self-concept of college engineering students for the mental health education and research of college engineering students. Based on overviews of former research, with the China College Student Psychological Stress Scale, the Coping Styles Scale and the Tennessee Self-Concept Scale, 559 college engineering students were investigated to explore the characteristics of and the relationship between the psychological stress, coping styles and self-concept of college engineering students. The results showed: 1. The stresses of learning, living and daily hassles were the main psychological stresses of college engineering students. There were significant differences in psychological stress between students from the countryside and those from urban areas, between needy students and non-needy students, between single-parent students and non-single-parent students, among students from different grades, with different academic achievements and of different postgraduate targets, between student party members and non-party members, between student cadres and non-cadres. However, there were no significant differences between male and female, between those from single-child families and from multiple-child families. 2. The coping styles of solving problem, seeking help and rationalization were the main coping styles of college engineering students. There were significant differences in the coping styles between needy students and non-needy students, among students from different grades, with different academic achievements and of different postgraduate targets, between student party members and non-party members, between student cadres and non-cadres. However, there were no significant differences between students from the countryside and from urban areas, between male and female, between single-parent students and non-single-parent students, between those from single-child families and from multiple-child families. 3. The self-concept of college engineering students was positive in general. There were significant differences in self-concept between students from the countryside and those from urban areas, between male and female, between needy students and non-needy students, between single-parent students and non-single-parent students, among students from different grades, with different academic achievements and of different postgraduate targets, between student party members and non-party members, between student cadres and non-cadres. However, there were no significant differences between those from single-child families and from multiple-child families. 4. The psychological stress had significantly negative correlation to the immature coping styles, and had partial correlation to the mature coping styles. Coping style has significant predictability on psychological stress. 5. The positive factors of the self-concept had significantly negative correlation to psychological stress, but self-criticism had positive correlation to psychological stress. There are significant differences between high self-concept students and low self-concept students for psychological stress. Self-concept has significant predictability on psychological stress. 6. The positive factors of the self-concept had significantly negative correlation to the coping styles of self-blame, illusion, avoidance, and rationalization, but had significantly positive correlation to the coping style of solving problem and seeking help. Self-criticism had significantly negative correlation to the coping styles of self-blame, illusion, avoidance, and rationalization. There are significant differences between high self-concept students and low self-concept students for coping styles. Self-concept has significant predictability on coping styles. 7. The self-concept of college engineering students had an effect on psychological stress by coping styles. However, the effect by the immature coping styles was higher than that to the mental health directly, and the effect by the mature and mixed coping styles was slighter than that to the mental health directly. According to the results, improving the college engineering students’ self-concept level and establishing right self-concept, developing the middle school student’ active coping styles and overcoming the negative coping styles are essential and important to the college engineering students’ mental health and provide useful clues for the psychological education of the college engineering students.

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The arguments on self discrepancy can be traced back to the old ages, but the systematic investigations were started by Higgins et al. at 1985.Compared to the large number of foreign studies, only a few ones have been conducted in our own country. Numerous characteristics of undergruaduate’s actual-ideal discrepancy and a great many determinative factors have been found as well as many of its negative effects—especially the greater the actual-ideal discrepancy, the more negative on the mind and behavior. Nevertheless, there are still many issues to be solved, such as the extend of the undergruaduate’s actual-ideal discrepancy level in own country. On the other hand, although there are a great many internal and external determinative factors of actual-ideal discrepancy, how they overally influence the discrepancy of the same individual is still unknown; to what extent does actual-ideal discrepancy influence the human mind and behavior and whether the influence is positive or negtive? This research collected a sample consisting of 4 undergraduate grades and 5 majors from a middle-ranked university. We adopted questionnaires in the study, and analyzed the data using correlation analysis, regression analysis, variances analysis, and path analysis. Our aim focused on the general characteristics of the undergruaduate’s actual-ideal discrepancy in own country, the overall working mechanism of the determinative factors including environmental and personal factors on the actual-ideal discrepancy of the same individual, and the effects of the actual-ideal discrepancy on psychological adaption, motivation, and behavior. The main results are as following: (1)The improved measurement instrument possesses good validity and reliability, and can be used in future research. (2) The actual-ideal discrepancy level among undergraduates is slightly bellow medium. The proportion of undergraduates who have a higher actual-ideal discrepancy level is small. There is significant gender difference in actual-ideal discrepancy level, but no significant difference across different majors and grades. (3)This research probed the overall working mechanism of the parenting style(environmental factors) and the personality factors(personal factors) including stability, flexibility, cleverness, and esteem on the undergruaduate’s actual-ideal discrepancy. The results shows that the parenting style of warmth and understanding, stability, flexibility, and esteem influence the actual-ideal discrepancy. Esteem entirely moderate the relationship between the parenting style of warmth and understanding and actual-ideal discrepancy, partially moderate the relationship between the flexibility, stability and actual-ideal discrepancy. Furthermore, the above factors can be order as stability, flexibility, and parenting style of warmth and understanding in terms of decreasing impact on the actual-ideal discrepancy. No significant effect of cleverness and other parenting style was found. The parenting style of warmth and understanding, stability, and flexibility interactively influence the actual-ideal discrepancy in the following manner: the stability and flexibility, both of which have independent influence on the actual-ideal discrepancy, entirely moderate the relationship between the parenting style of warmth and understanding and actual-ideal discrepancy. (4) Actual-ideal discrepancy plays a negative role in adaption indices, including self-efficacy, self-identity, self-actualization. Actual-ideal discrepancy also has negative effects on the 9 symptoms measured by SCL-90, vitality, approach motivation, avoidance motivation, and performance goals. No significant influence on mastering goals was found. Actual-ideal discrepancy uniquely correlates with depression symptom. The above results contribute from the point of self-discrepancy to the understanding of self-identity of undergraduates, and they enrich the knowledge of the development of self and contribute to the understanding of the development of human personality.This research advances on the two key problems of the developmental mechanism of actual-ideal discrepancy and that promotes the knowledge of the developmental mechanism of actual-ideal discrepancy. The research probed the relationship between the actual-ideal discrepancy and motivation which is an important phenomenon and this enlarges the domain of the actual-ideal discrepancy research. The results make sure that actual-ideal discrepancy is one of the important factors influencing undergruaduate’s mind and behavior. The conclusions can provide reference and guidance in the diagnosis and intervension strategies for mental health education and counseling practice in university.

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Prenatal morphine exposure affects neural development of fetus by impairing learning and memory, and increasing susceptibility to morphine abuse. Because nervous systems have different developmental characteristics during different developmental stages, administration of morphine at different stages also has different effects on learning, memory, and susceptibility to morphine. Due to the precise developmental processes of neurotransmitter systems in chick embryo’s brain, and unique superiority of chick embryo model, the purpose of the present studies was to explore critical periods correlated to the memory impairment and the increasing susceptibility to morphine, via one-trial passive avoidance and conditioned place preference as behavior models. Then the possible roles of mu and delta opioid receptors as the possible mechanism were analyzed. Experiment 1 showed that injecting low dose of morphine (1 mg/kg) during the period embryonic 5 to 8 significantly impaired the function of learning and memory, worse than any other periods of the same treatment. Experiment 2 showed that injecting low dose of morphine during the period embryonic 17 to 20 significantly increased the susceptibility to morphine in the new-born chicks. The affected chicks acquired the morphine conditioned place preference more quickly, and maintained it much longer. Experiment 3 showed that during E5-8, injecting delta receptor antagonist naltrindole reversed the learning and memory impairment caused by morphine while delta receptor agonist DPDPE impaired learning and partial memory function. On the other hand, mu opioid receptors had little effect. As for E17-20, given naloxonazine can reverse the increases of susceptibility to morphine, and the mu receptor agonist DAGO cause the increases of susceptibility to morphine. Delta receptors have no effect. The above results demonstrated that prenatal morphine expousure at different developmental periods of chick embryo caused different influences on memory and susceptibility to morphine. That is, E5-8 is the critical period correlate to memory impairment; and E17-20 is the critical period correlate to susceptibility to morphine. Delta receptors were critical in learning and memory impairment while mu receptors in susceptibility.

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Relapse has been a great challenge in clinical treatment and experimental studies of drug addiction. Recent studies suggest that psychological dependence may play a major role in addiction relapse, even more important than physiological dependence. Then a fundamental question arises: how to measure the psychological dependence? How to examine whether an addict has psychologically quitted when leaving drug rehabilitation centers? Self-report, a commonly used evaluation approach, is inevitably vulnerable to various cognitive influences, particularly in explicit tasks. Therefore, an objective index is necessary to evaluate the subliminal psychological drug dependence level. The objective of the current study was to develop such a psychological paradigm to probe the unaware attentional bias of in smoking addicts. Experiment 1 adapted the interocular suppression technique of binocular rivalry to study the attentional bias to cigarette pictures in smokers and age-matched nonsmoker. Results show that the smokers demonstrated similar attentional bias in both visible and unaware conditions, while non-smokers showed attentional bias only in the visible condition, and there was a significant interaction between experiment conditions and subject groups. These results provide compelling evidence for addiction-specific attentional bias in cigarette smokers, by minimizing the influence of confounding conscious factors. Furthermore, attentional bias of smokers in unawareness state was negatively correlated with their cigarette dependence levels, while their pre-test cigarette craving levels was positively correlated with their attnetional bias in the visible condition. This pair of correlations further demonstrated the advantages of unawareness state in disclosing stable dependence states, therefore supporting the effectiveness of the paradigm used in this study. Another interesting finding of Experiment 1 is that non-smokers also showed attentional bias in the visible condition. To exclude the possibility that the attentional bias found in experiment 1 was task-specific, experiment 2 adapted the most commonly-used visual dot probe task with smoking scenes as in relevant reference. The result in experiment 1 was well replicated, i.e., nonsmokers in experiment 2 also showed significant attentional bias to smoking-related stimuli, We interpenetrate this interesting finding as an effect of environmental influence, as the participants of the current study live in a highly smoking-exposed and smoking-encouraged environment, which is quite different with the participants of studies reported in the literature. A series of questionnaires and scales administered in the current study indeed show that most smokers smoked due to influence of the environment. They also acknowledged that smoking as an important media of social communication in China, and even considered that away from the smoking environment would effectively help them to quit. The current study also found that the disgust level towards cigarette pictures and smoking-related scenes of non-smokers was positively correlated with their attnentional bias in the visible condition of experiment 1. It is likely that in a highly smoking-encouraged environment, the remaining few on-smokers have severe disgust to cigarettes and smoking scenes; and their attentional bias might be caused by disgust avoidance. In conclusion, the current study represents the first study showing the existence of unaware attentional bias to smoking related stimuli in cigarette smokers by applying the interocular suppression paradigm, providing a reference to study of dependence of other drugs. The current study also found that our non-smoking participants also showed attentional bias to smoking related stimuli, which may be due to the possible influence of highly smoking-exposed environment of our participants.

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It has been shown that prenatal light exposure and corticosterone improve memory retention of dark hatched chicks. The object of this study was to explore the neural mechanisms underlying the effect of prenatal light exposure and corticosterone on memory retention of chicks. To detect the effect of different prenatal treatments on memory retention of chicks, we used one-trial passive avoidance model. To examine the expression of glucocorticoid receptor (GR), neural cell adhesion molecule (NCAM), growth-associated protein 43 (GAP-43) and polysialic acid (PSA) in HV and LPO of chick brain, we used immunohistochemical method. Prenatal light exposure and glucocorticoid (corticosterone, dexamthesone) administered in embryonic day 20 (E20) markedly improve memory retention in dark hatched chicks. Light plays a critical role in improving memory. The critical exposure period is E19 and E20. The effect of these two hormones and light exposure can be significantly blocked by their receptor antagonist administration respectively. The light, corticosterone and particularly darkness significantly up-regulated the level of GR; the expression of NCAM and GAP-43 in HV and LPO peaked in E20 in normal hatched chicks and was significantly increased by light exposure and corticosterone. Protein synthesis inhibitor anisomycin markedly reduced the effect of light exposure but partially reduced the effect of corticosterone; light exposure and corticosterone in E20 significantly up-regulated PSA expression. Removing PSA from NCAM significantly retarded the effect of corticosterone on memory retention in chicks. Therefore, The effects of prenatal light exposure and corticosterone on memory retention are mediated via both corticosteroid receptors. The effects of both prenatal light and corticosterone might at first change the plasticity of the brain by up-regulation the synthesis and modification of proteins, and then influence the behavior performance of the chicks.

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A set of tools of clinical psychological intervention for cancer patients had been composed for the first time in the form of a manual with three tapes and some pictures. The cancer patients during chemotherapy were treated by psychological intervention via the tools in group and individual therapy. QLQ-C30, POMS-SF and DWI-CI were first recommended and used as indicators for measuring the results of QoL, emotion and coping method in cancer patients in Chinese mainland. NK cell activity and IgG、IgM, IgA were used to measure the immune function. 120 cancer chemotherapy patients were randomly assigned to one of four conditions formed by a 2 (pre-chemotherapy and post-chemotherapy) *2 (experimental and control group) factorial design. The effect of psychological intervention on quality of life and immune function for cancer patients was investigated as well as the mediate role of coping method and personality and their factors. The efficiency of the tools was verified. The major conclusive results drawn out from the study were: 1. After treated by psychological intervention for three months, the status of quality of life and the symptoms of the patients during the chemotherapy was improved accompanying with the increase of immune parameters, especially the NK cell activity. The influential way of the factors, which effected on the effect of psychological intervention on the quality of life, immune parameters and coping methods, was synthetic. There was obvious mutual effects among the factors. 2. The patients of experimental group used more the active behavior, more the active cognition and less the avoidance coping method than those in control group. 3. The results of measurement showed that the personality of the caner patients was of obvious concealing and hiding. 4. Quality of Life Questionnaire-Core 30(QLQ-C30) was suitable for the cancer patients with great efficiency in Chinese mainland although the scale of SF needed to be revised in the light of Chinese culture.

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In the processes of Chinese economic and political reforms, it has many problems in the international corporations because of the difference of cultures. This research try to compare the Chinese managers and other conntries' through the investigation of 435 managers and employee from 9 units in Beijing. We used Hofstede's "Value Survey Module" (1980), Compared to Cultures in power distance, uncertainly avoidance, individualism-collectivism, masculinity. We also compared the employee's attitude with three patterns. The conclusions are: 1. There is not significant level difference in three patterns. 2. At PDI、UAI、IDV、MAS the fonr dimensions, our invested results approach Hofsteds's invested results. This is high at PDI, but middle at UAI、IDV、MAS.