基于MUGG的轨迹建模与异常检测     

桂树  郭立  陆海先  谢锦生 《中国科学院大学学报》2013,30(2):244-250

构建视频场景中目标轨迹分布的概率模型--混合单边广义高斯模型,通过计算目标轨迹的信息量分析目标轨迹是否异常.该方法不依赖场景的先验知识,模型建立过程无监督,且模型能实时更新以适应时变环境.实验表明,该方法的有效性和鲁棒性,具有一定的应用价值.  相似文献   

裂隙岩体块体几何识别研究     

沈振涯  肖俊  王颖  隋红建 《中国科学院大学学报》2012,29(1):81-87

回顾了块体几何识别研究的发展过程,依据模型的空间维数和切割方法将其分为3个阶段,并分类分析了各个阶段的代表性研究成果.从原理、构建、效率和应用等角度对三维块体全空间识别算法进行比较,归纳出块体识别方法的一般数学描述. 指出了当前三维块体全空间识别存在的问题和进一步研究的方向.  相似文献   

伴随模式在反恐情报同步轨迹数据分析中的应用研究     

李勇男 《现代情报》2018,38(12):65-69

[目的/意义]对反恐情报中的时空轨迹数据进行伴随模式挖掘,可以发现涉恐群体的同时间段动态空间位置移动规律。[方法/过程]根据反恐情报数据的特点,修改经典伴随模式挖掘方法中的相似度度量方式和聚类方式,不断迭代完成"聚类和取交集"操作,将满足条件的涉恐活动时空轨迹伴随模式导出。[结果/结论]该方法能够挖掘涉恐群体的同步移动路径,定位重点活动地点,分析涉恐人员之间的亲近度,为打击暴恐活动提供数据参考。  相似文献   

Utilization of cues in action anticipation in table tennis players     

Qi Zhao  Kyle J. Jaquess  Chenglin Zhou 《Journal of sports sciences》2018,36(23):2699-2705

ABSTRACT

By manipulating the congruency between body kinematics and subsequent ball trajectory, this study investigated the anticipation capabilities of regional-level, college-level, and novice table tennis players using a full video simulation occluder paradigm. Participants watched footage containing congruent, incongruent, or no ball trajectory information, to predict the landing point of the ball. They were required to choose between two potential locations to make their prediction. Percent accuracy and relevant indexes (d-prime, criterion, effect size) were calculated for each condition. Results indicated that experienced table tennis players (both regional and college players) were superior to novices in the ability to anticipate ball trajectory using kinematic information, but no difference was found between regional-level and college-level players. The findings of this study further demonstrate the superior anticipation ability of experienced table tennis players. Furthermore, the present result suggests that there may be a certain “baseline” level of motor experience in racquet sports for effective action anticipation, while the addition of further motor experience does not appear to assist direction anticipation.  相似文献   

The relationship between the golf swing plane and ball impact characteristics using trajectory ellipse fitting     

Andrew Morrison  Denise McGrath  Eric S. Wallace 《Journal of sports sciences》2018,36(3):303-310

The trajectory of the clubhead close to ball impact during the golf swing has previously been shown to be planar. However, the relationship between the plane orientation and the orientation characteristics of the clubhead at ball impact has yet to be defined. Fifty-two male golfers (27 high skilled, 25 intermediate skilled) hit 40 drives each in an indoor biomechanics laboratory. This study successfully fitted the trajectory of the clubhead near impact to an ellipse for each swing for players of different skill levels to help better explain this relationship. Additionally, the eccentricities of the ellipses were investigated for links to skill level. The trajectory of the clubhead was found to fit to an ellipse with RMSE of 1.2 mm. The eccentricity of the ellipse was found to be greater in the high-skilled golfers. The club path and angle of attack generated from the ellipse fitted clubhead trajectory were found to have a normalised bias-corrected RMSE of 2% and 3%, respectively. A set of “rule of thumb” values for the relationship between the club path, angle of attack and delivery plane angle was generated for use by coaches.  相似文献   

改进式旋风除尘器内部两相流的数值模拟研究     

张野  王黎黎 《黑龙江科技信息》2013,(15):76-77,75

旋风除尘器是一种利用气固两相流体的旋转运动,使固体颗粒在离心力作用下从气流中分离出来的设备。当前,日益严重的能源危机和环保问题使得除尘器向低阻高效方向发展,而广泛应用的各种形式的旋风除尘器在实际运行过程当中,其性能指标还远不能满足要求,尤其是在对处理含尘量较低、颗粒粒径较小气体这一应用领域。基于两相流基本理论对旋风除尘器内部流场进行了深入的研究和分析,运用FLUENT模拟软件确定适合旋风除尘器的数值模拟方法。为了更好的适应工业实际需要,提出了一种新型的旋风除尘器结构,并就其流场和性能进行研究。结果表明,改进后的旋风除尘器除尘效率提升最高可达3.28%,压力损失最大减少40%以上。结果对于了解旋风除尘器的分离机理和内部流场的复杂运动规律,提高旋风除尘器的除尘效率,改善和优化旋风除尘器的结构具有重要意义。  相似文献   

徐淮地区新构造控水作用及地下水富集带分布特征     

唐泽华 《大众科技》2013,(8):38-39

徐淮地区的徐宿弧形逆冲推覆断裂构造体系,由一系列近南北向背斜向斜构造和逆冲推覆断裂构成。寒武、奥陶系厚层灰岩中岩溶裂隙水为区域内主要储导水岩系,由推覆构造内一系列的南北向背斜、向斜构成集储水构造。受推覆构造格架制约及岩系隔水岩层的阻隔,难以形成较大规模的地下水富集带。通过查找区内新构造破裂构造带,查明了区内地下水分布规律,确定了区域地下水富集带。确定了其展布空间的方向性,原位破裂性,几乎直立性,延展远,具有间隔性,等距性特征。查找出徐淮地区地下水储集富水带,为该地区地下水开发提供了新的途径。  相似文献   

篆刻艺术在美术教学中的探索与创新实践     

邬丹 《科教文汇》2013,(11):125-125,129

篆刻艺术源远流长,在历史的长河中去伪存精,形成了阴文粗壮,阳文劲挺的线条特色及疏密有致,刚柔相济的章法特色,是一门与书法密切结合的传统艺术。由于其使用材料的特殊性与技法的专业性及篆刻教学难度较大等原因,一些学生的学习积极性也受到影响。笔者通过反复的教学实践,探索出了以结合现代设计手法及形式的橡皮章印刻代替传统的篆刻教学,使篆刻这一传统的艺术焕发出年轻的生命力,取得了较好的效果。  相似文献   

A review on the basketball jump shot     

Victor H.A. Okazaki  André L.F. Rodacki  Miriam N. Satern 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):190-205

The ability to shoot an effective jump shot in the sport of basketball is critical to a player's success. In an attempt to better understand the aspects related to expert performance, researchers have investigated successful free throws and jump shots of various basketball players and identified movement variables that contribute to their success. The purpose of this study was to complete a systematic review of the scientific literature on the basketball free throw and jump shot for the purpose of revealing the critical components of shooting that coaches, teachers, and players should focus on when teaching, learning, practising, and performing a jump shot. The results of this review are presented in three sections: (a) variables that affect ball trajectory, (b) phases of the jump shot, and (c) additional variables that influence shooting.  相似文献   

土坝裂缝的预防与治理   总被引：2，自引：0，他引：2  

赵旭升  冯旭  苏德乾 《杨凌职业技术学院学报》2004,3(1):28-31

土坝裂缝直接危及大坝安全，应采取相应的处理方法和措施。本文着重阐述了开挖回填法和灌浆法两种土坝裂缝加固处理措施的方法、步骤，并对土坝裂缝的预防作了简单论述。它对土坝裂缝处理的设计、施工和日常维护管理及常规观测等工作提供了借鉴。  相似文献