945 resultados para experiential avoidance


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提出了一种用于AUV视景仿真的海洋环境中海底地形和海流的虚拟实现方法。海底地形不但考虑了离散点电子海图数据,而且也将某些特征数据考虑在内,从而生成相对精度较高的海底地形。海洋中的海流采用两个层次的方法进行模拟:建立海流数据库方法以及水动力软件计算方法。该方法的研究对于AUV自主地形导航技术以及避碰策略等研究具有极为重要的意义,并且上述方法生成的海洋环境已经在AUV数字仿真平台中得到了应用。

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海洋环境通常是不确定、非结构化和未知的 ,而远程AUV(LAUV)的避障声纳对环境感知有一定的局限 ,因此很难建立起精确、完整和统一的三维环境模型 .LAUV实时避障是一个实时性很强的动态过程 ,它不但与环境有关 ,而且还与LAUV的运动学约束、动力学特性和操纵性有关 .针对上述问题本文提出了一种基于复合控制的三维实时模糊避障方法

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自主水下机器人(AUV)要在复杂未知环境中自主作业,实时避碰是一种必不可少的自我保护能力。同时,能自动检测、识别、避开障碍也是AUV拥有“智能”的重要体现。因此,无论从实际应用前景还是从理论研究意义方面看,AUV实时避碰方法都具有重要的研究价值。 能使AUV像鱼儿一样自主地规避障碍一直是研究者追求的理想目标。但是,现有研究成果多倾向于AUV单个平面(水平面或垂直面)的避碰方法研究,而忽略了AUV是在三维空间运动的载体。在对现有AUV实时避碰方法进行深入分析和研究的基础上,本文提出了水平面和垂直面相结合的三维实时避碰方法,并针对以测距声纳为避碰传感器的一类远距离航行AUV,重点研究了三维避碰实现中的四个基本问题:一是如何从含有虚警的传感器原始数据中提取障碍信息;二是如何根据障碍信息决策规避行为;三是如何避免实时避碰行为陷入死循环或局部陷阱区域;四是如何评价和验证AUV实时避碰性能。 本文的主要研究内容及研究结论概述如下: 首先,针对测距声纳在实际应用中普遍存在的虚警和伪值问题,研究了基于D-S证据理论的数据融合方法。该方法包含4个部分:测距声纳模型、环境建模、一致性决策规则和证据融合。根据测距声纳和AUV的特殊性,本文分别提出了一种可根据载体航行速度和转动角度实时调整置信区域和基本可信度分配的测距声纳动态模型、基于灰数概念的一致性检验规则和基于确定性比例的冲突值分配方法。仿真和试验数据表明:基于D-S证据理论的数据融合方法比正则化方法、贝叶斯方法具有更高的检测概率和更低的漏检概率,能有效消除虚警信息、生成静态障碍环境的证据地图。 其次,从运动规划和路径规划两个层次研究了AUV三维实时避碰方法。在运动规划层,AUV要对视野内的障碍做出即时、准确的响应。这个响应包括改变航向、深/高度和降低航行速度。本文从多输入多输出模糊系统解耦设计的角度,将三维避碰行为分解为水平面和垂直面避碰行为,分别设计了2个双输入-单输出的模糊控制器;然后引入基于有限自动机的离散事件动态系统分析理论,建立了三维避碰过程有限自动机和基于事件反馈的监控器自动机;该自动机实现了水平面避碰行为、垂直面避碰行为、水平面和垂直面相结合的三维避碰行为之间的自主切换。 由于运动规划层的实时避碰行为存在“短视”的缺陷,要使AUV彻底摆脱当前障碍、逃离陷阱区域、避免出现死锁现象,需要在更高一级的路径规划层建立实时规划模块,负责根据离线地图和已获得的在线地图规划出远离障碍的优选路径。为此,本文研究了基于免疫遗传算法的实时路径规划方法。主要改进措施包括:提出以路径段数划分种群的小生境技术;采用细胞克隆和遗传操作并行搜索的策略;建立一组更适于AUV实时路径规划特殊性的适应性函数;利用疫苗接种机制改善抗体群质量。仿真实验表明:所提出的免疫遗传算法在收敛性能方面优于遗传算法和免疫算法,能满足AUV实时路径规划模块的要求,能实时产生避开复杂障碍的有效路径。 再次,本文第五章用上述测距声纳数据融合方法、模糊避碰规划方法、实时路径规划方法构建了AUV实时避碰系统,并在多功能半物理仿真平台上开展了仿真实验研究。多种典型单个和多个障碍场景的仿真实验全面演示、验证了AUV水平面、垂直面和三维的避碰能力,同时证明:基于事件反馈监控的模糊避碰规划方法能够引导AUV通过大部分复杂的未知障碍区域;基于免疫遗传算法的实时路径规划方法不仅能在线规划出远离障碍的优选路径,而且能帮助AUV逃离陷阱区域;所构建的AUV实时避碰系统能够实现AUV连续、稳定的三维实时避碰过程。另外,所提出的模糊避碰规划方法已在实际AUV上得到应用,并通过了湖上试验验证。 最后,研究了AUV实时避碰系统的评价和验证问题。共有三项成果:一是从系统工程角度创新性地提出实时避碰系统三维结构模型;二是建立一种AUV实时避碰能力综合评价体系,明确了单项和综合评价指标的组成因素;最后为评价和验证实时避碰系统,设计了多种典型障碍场景。 自主水下机器人实时避碰是一项极具挑战性的研究课题,本文只是针对一类欠驱动AUV、基于测距声纳研究了一种实时避碰系统的实现方法,并用仿真和试验验证了该系统的可行性和有效性。

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本文采用集中预规划方法 ,通过调整机器人的运动速度实现多机器人避碰 ,所提算法的基本思想为 :将机器人的运动路径分段 ,然后按避碰要求对机器人通过各段的时间进行约束 ,从而将避碰问题转化为高维线性空间的优化问题 ,并进一步将其转化为线性方程的求解 ,使问题具有明确的解析解 .由于该方法的复杂度较高 ,在实现过程中采用了多种方法降低复杂度 ,简化计算 .本文给出了该算法的基本思路 ,有关定理及证明 ,算法的化简方法 ,最后给出了实验结果及分析 .

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研究在同一工作环境中多移动机器人的运动规划问题,提出将原来比较复杂的大系统问题转化为相对简单的子系统,由各智能机器人依据任务要求和环境变化,独立调整自身运动状态,完成任务的分布式智能决策体系结构,并给出相应的模型和算法

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研究移动机器人在动态环境中的导航与避障问题。为提高规划的实时性,提出了基于规则的规划方法,将多移动障碍环境机器人的运动规划分解为相对简单的单移动障碍运动规划,利用最优控制来实现单障碍的最优避障,并用智能搜索方法解决了移动机器人在多移动障碍环境中的实时运动规划问题。仿真实例表明了该方法的有效性。

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研究了不确定性环境下移动机器人躲避运动轨迹未知的移动障碍物的一种新方法.通过实时最小均方误差估计算法预测每个障碍物的位置及运动轨迹,并利用模式识别中最小均方误差分类器的修正模型计算出机器人的局部避障路径,再运用船舶导航中使用的操纵盘技术来确定每个导航周期中移动机器人的速.度仿真结果表明了该方法的可行性

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研究了一种高冗余自由度并串联机构回避障碍的算法问题,并实现了运动仿真,核算法应用了优先顺位的理论,利用旋转张量法,对杆长随时间变化的高冗余自由度操作臂实现了变臂长的避障规划,并在CAD工作站上完成了回避障碍钻洞的运动仿真,获得了满意的结果。国家自然科学基金

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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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本文在分析、归纳、综合的基础上作出了7自由度机械臂的图谱.包括位置空间、奇异空间、回避障碍和回避奇异等问题.给出了一种普遍适用的方法.并介绍了该方法的使用,对7自由度机器人的结构设计和选型有一定的参考价值.

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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.