水平定向对接穿越导向系统设计

水平定向对接穿越技术有效地解决了传统水平定向钻进无法进行长距离穿越,以及含砾石等复杂地层穿越的问题。在已有水平定向钻进工艺的基础上,实现对接穿越的关键在于成功进行导向孔对接。描述了一种水平定向对接穿越导向系统,系统采用三轴加速度计和磁阻传感器作为姿态敏感器件,以轴向磁铁产生的磁场作为对接磁源,介绍了系统的工作原理,以及系统的结构和功能。此系统具有体积小、成本低、精度和可靠性高等一系列优点,适用于水平定向对接穿越的导向。     

平底筒形件主动径向加压充液拉深的数值模拟

针对低塑性、大高径比航天铝合金板材零件成形需要,提出了带主动径向加压的充液拉深新技术.通过数值模拟方法,采用动力显式分析软件ETA/Dynaform5.5对5A06铝合金平底筒形零件主动径向加压充液拉深成形过程进行了研究.以零件成形最终壁厚分布为评定标准,分析了不同主动径向压力加载路径对成形质量的影响.通过数值模拟证明了在主动径向加压充液拉深过程中,法兰变形区存在一个应力分界线,随着主动径向液压力的增加,分界线的位置内移.研究表明,采用40 MPa的液室压力加载曲线,并配合45 MPa的主动径向压力加载路径,获得的铝合金平底筒形件的拉深比为3.1,零件质量好.     

Stochastic distributed optimization of shapeable energy resources in low voltage distribution networks under limited communications

Due to the rising renewable penetration rate, modern low voltage distribution network (LVDN) calls for active control with tractable computation and limited communication. To tackle this, the paper proposes a novel stochastic distributed optimization approach. The computation of optimum is completely decentralized, with a global broadcast signal is used as public reference in order to guarantee the consistency among individual shapeable energy resources. The proposed approach employs Bernoulli trials to imitate the searching process in classical gradient descent approach, and player compatible relationship is employed to play the role of gradients to indicate the direction of the search. Working in a model‐free manner without relying on iterations, the proposed approach offers an approximate optimization to minimize the accumulated compensation of reshaping/deferring the shapeable energy resources in a given LVDN while respecting the system constraints. A 103 nodes test network based on a realistic Belgian semi‐urban distribution network is used for validation. With two different profiles and a special case of communication failure, the proposed approach is validated and benchmarked with a classical AC optimal power flow algorithm. The results prove that the proposed approach is able to deliver a good approximation to the theoretical optimum with reasonable gap.     

一种高清晰度硬盘录放机

介绍了一种简单、可靠、功能强大且性价比高的高清晰度硬盘录放机整体方案。它可实现TS流的输入、解码、显示并将其以独创的文件系统格式存储到硬盘中;还可对硬盘中的高清视频文件进行各种特技播放等操作,具有强的容错能力。     

飞机铝合金深锥型面零件多道次充液拉深技术

目的随着新一代飞机在隐身和战斗性能方面的提高,飞机钣金零件的复杂程度和制造精度要求也越来越高。对于深型腔复杂型面零件,充液拉深是一种有效的精密制造方法。方法针对难成形、复杂型面的某型飞机铝合金深锥零件,利用理论分析、有限元模拟和工艺试验相结合的方法,设计了多道次充液拉深技术方案,并建立有限元分析模型。基于等裕量函数法和零件锥面特征,分配并优化了不同道次的材料变形量。结果对多道次充液拉深成形过程中出现的起皱和破裂的失效形式进行了研究,分析了预成形高度,液室压力和压边力等关键工艺参数对零件成形质量的影响,获得了优化的预成形高度和液室压力加载轨迹。结论结果表明,提出的多道次充液成形技术能够实现复杂型面,大拉深比的铝合金零件的整体精确成形,采用优化的工艺参数能够成形出壁厚均匀,表面质量好,锥面精度高的零件。     

Development of a fuzzy decision support framework for complex multi‐attribute decision problems: A case study for the selection of skilful basketball players

The selection of skilful players is a complicated process due to the problem criteria consisting of both qualitative and quantitative attributes as well as vague linguistic terms. This study seeks to develop a decision support framework for the selection of candidates eligible to become basketball players through the use of a fuzzy multi‐attribute decision making (MADM) algorithm. The proposed model is based on fuzzy analytic hierarchy process (FAHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) methods. The model was employed in the Youth and Sports Center of Mugla, Turkey, with the participation of seven junior basketball players aged between 7 and 14. In the present study, physical fitness measurement values and observation values of technical skills were utilized. FAHP was used to determine the weights of the criteria and the observation values of technical skills by decision makers. Physical fitness measurement values were converted to fuzzy values by using a fuzzy set approach. Subsequently, the overall ranking of the candidate players was determined by the TOPSIS method. Results were compared with human experts’ opinions. It is observed that the developed model is more reliable to be used in decision making. The model architecture and experimental results along with illustrative examples are further demonstrated in the study.     

以用户为中心的音乐播放器设计分析

随着个人计算机的普及,音乐播放器渐渐成为人们使用频率很高的一种软件。开电脑后打开播放器听音乐成了一种很自然的行为。怎样的播放器设计才是能赢得用户青睐的,从设计的角度需要注意到哪些设计要点?在这里,作者将从界面设计者的角度,通过对千千静听这一较为成功软件进行案例分析,对以用户为中心的音乐播放软件界面的设计作一些分析讨论。     

基于传感器信息的多机器人任务分配研究

多机器人协作是当前机器人学和人工智能的研究热点之一。针对多机器人系统中的任务分配问题,提出一种基于集中式和分布式的混合式控制结构,在机器人得到传感器信息后,使用合同网协议来完成任务分配,最终实现多机器人协作。在player/stage仿真平台进行的实验表明:多机器人系统能够有效地进行任务分配与协作,提出的解决方案是行之有效的。     

Online behavior change detection in computer games

Player Modelling has been receiving much attention from the game community in the recent years. The ability to build accurate models of player behavior can be useful in many aspects of a game. One important aspect is the tracking of a player’s behavior along time, informing every time a change is perceived. This way, the game Artificial Intelligence can adapt itself to better respond to this new behavior. In order to build models of player behavior, researchers frequently resort to Machine Learning techniques. Such methods work on previously recorded game metrics representing player’s interactions with the game environment. However, if the player changes styles over time, the constructed models get out of date. In order to address this drawback, this work proposes the use of and incremental learning technique to track a player’s behavior during his/her interaction with the game environment. Our approach attempts to automatically detect the moments in time when the player changes behavior. We apply a change detection technique from the area of Data Stream Mining that is based on incremental clustering and novelty detection. We also propose three modifications to the original technique, in order to formalize change detection, improve detection rate and reduce detection delay. Simulations were performed considering data produced by the Unreal Tournament game, showing the applicability of the method to online tracking of a player’s behavior and informing whenever behavior changes occur.     

基于J2ME的移动视频技术研究

基于J2ME体系框架,结合MMAPI技术,设计并实现了一个移动媒体播放器。重点阐述了MMAPI技术及播放器类的设计。