一种基于车载MP3播放机的倒车雷达设计

提出了一种基于车载MP3播放机-SH252的倒车雷达设计方案,并介绍了系统的软硬件设计思路。系统采用EM78P153单片机作为倒车雷达数据采集部分,采用超声波探测方式测距。在倒车时,倒车雷达会自动启动,并在EM78P153的控制下,由装置于车尾保险杠上的探头发送超声波信号,当遇到障碍物时,产生回波信号,探头接收到回波信号后经控制器进行数据处理并计算出车体与障碍物之间的实际距离,然后将数据发送到车载MP3播放机上进行距离显示和语音同步提示,为驾驶员提供报警提示,提高驾驶的安全性。     

硬盘播放机的运输包装设计研究

由于硬盘播放机运输距离较远,为减少运输成本,以某款硬盘播放机的运输包装为研究对象,在保障运输过程中产品不破损的条件下,以40英尺的货柜为运输单元,提出了3种包装设计方案,从产品保护性、缓冲性能、经济性、环保性结合客户意见,对3个方案进行了评估,选择了最终的方案。根据选择的方案制作了包装样品,在环境试验和运输包装测试的基础上,进一步修改和优化了设计方案,使产品装载量提高了5%,经厂方鉴定后已投入工业实际应用。     

Virtually real: A psychological perspective on massively multiplayer online games.

Massively multiplayer games (MMOs) are immersive virtual three-dimensional fantasy worlds in which people cooperate and compete with each other, as well as with the computer-generated denizens of that particular game world. Although typically seen as games, their strong social aspect suggests that they are a form of online communication tool, with which players interact to form friendships, create communities, and work together to accomplish a variety of goals. After an introduction to MMOs, this review explores how social aspects of the game imitate the real world in terms of choices that players make when interacting with others. Furthermore, player-to-player interactions are examined in terms of in-game group formation and how efficient communication is imperative for goal achievement. The review also explores how leadership skills learned in-game may be transferred to real-world scenarios. The reasons why people play MMOs are examined in terms of player motivations and how aspects of game play may have both positive and negative consequences for a player's well-being. The latter half of the review describes how MMOs are used as afterschool virtual teaching environments where students can use aspects of game play to learn, for example, leadership qualities. The review concludes with recommendations for using MMOs as virtual laboratories to explore aspects of human behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

S3C2440嵌入式音频系统设计与实现

设计开发的基于ARM处理器可同时实现网络收音机和MP3播放器功能的嵌入式平台。利用S3C2440芯片的特点,以ARM处理器及其外围模块为硬件平台,采用嵌入式Linux作为操作系统,用MPLAYER播放软件,实现了MP3播放器及网络收音机的全部功能。在软件方面,为了更好支持对音频数据的播放,在Mplayer源码中添加Madlib库和Live协议包。测试结果表明,系统性能良好,具有较好的市场应用前景。     

2011年11月十大重要安全漏洞分析

国家计算机网络入侵防范中心在该文中介绍了2011年11月份的网络安全漏洞的整体情况,分别统计了“紧急”、“高”、“中”、“低”不同威胁级别的漏洞数量,并从中选取了十个重要安全漏洞,对其内容和危害进行了分析,进而提出了应对的措施.     

自适应防漏堵漏钻井液技术研究

针对钻井液漏失地层非均质性强及漏失通道尺寸难以准确预知等问题,提出了自适应防漏堵漏钻井液技术。该技术无须明确预知漏失地层孔喉直径,能自适应封堵岩石表面较大范围的孔喉,对较宽孔径分布的漏层具有很好的封堵作用,封堵速度快,封堵层浅,适合于油层防漏、堵漏。室内评价表明,自适应防漏堵漏钻井液能在一定范围内对不同孔径分布的漏层产生良好的封堵作用。封堵率达到90%以上,封堵带压力强度大于9MPa,封堵厚度小于1cm,切片后渗透率恢复率达90%以上。现场应用证明,自适应防漏堵漏钻井液能有效提高地层的承压能力,并且有良好的防漏及堵漏效果。     

Frequency-dependent performance and handedness in professional baseball players (Homo sapiens).

I used data on handedness and pitching and hitting performance in annual cohorts of professional baseball players (1957-2005) to test the hypothesis that handedness among pitchers was subject to negative frequency-dependent selection. As predicted by this hypothesis, right-handed pitchers were more successful (i.e., opposing batters hit more poorly against them) when they were relatively rare in the population. Contrary to the predictions of this hypothesis, however, left-handed pitchers were more successful when they were relatively common. Both right- and left-handed batters performed better in years dominated by right-handed pitchers, despite the fact that right-handed batters perform relatively poorly against right-handed pitchers. I suggest that batters form cognitive representations based on pitcher handedness, and that these representations are strengthened by repeated exposure or priming. When the pitcher handedness polymorphism is more balanced (e.g., 67% right-handed, 33% left-handed), these cognitive representations are less effective, which leads to decreased batting averages and improved performance by all pitchers. Furthermore, these cognitive representations are likely to be more critical to the success of right-handed hitters, who have reduced visuomotor skills relative to left-handed hitters. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

矫正规则散光的光学演示模型研制

目的:研制规则散光眼镜片矫正规则散光的光学演示模型。方法:用几何光学成像演示器直观演示规则散光成像、规则散光透镜成像、规则散光透镜矫正规则散光。结果:直接观察到规则散光和散光透镜的成像状态-散光Sturm光锥及散光透镜矫正规则散光的光学效果。结论:规则散光眼镜片矫正规则散光的光学演示模型能观察到规则散光透镜矫正规则散光的光学效果,便于准确理解规则散光成像、规则散光透镜的成像、规则散光矫正的光学原理。     

谈足球新队员在比赛时的情绪调节与控制

新队员在比赛过程中, 由于缺乏应变能力, 易造成情绪紧张, 从而导致在比赛中的运动行为发生变化, 这将对比赛进程和比赛结果产生影响。因此, 教练员如能了解和掌握这些情绪变化, 便可以有效地调控新队员的比赛行为, 使其运动技术水平在比赛中更好的发挥出来。     

Automatic playlist generation based on tracking user’s listening habits

Algorithms for automatic playlist generation solve the problem of tedious and time consuming manual selection of musical playlists. These algorithms generate playlists according to the user’s music preferences of the moment. The user describes his preferences either by manually inputting a couple of example songs, or by defining constraints for the choice of music. The approaches to automatic playlist generation up to now were based on examining the metadata attached to the music pieces. Some of them took also the listening history into account. But anyway, a heavy accent has been put on the metadata, while the listening history, if it was used at all, had a minor role. Missings and errors in metadata frequently appear, especially when the music is acquired from the Internet. When the metadata is missing or wrong, the approaches proposed so far cannot work. Besides, entering constraints for the playlist generation can be a difficult activity. In our approach we ignored the metadata and focused on examining the listening habits. We developed two simple algorithms that track the listening habits and form a listener model—a profile of listening habits. The listener model is then used for automatic playlist generation. We developed a simple media player which tracks the listening habits and generates playlists according to the listener model. We tried the solution with a group of users. The experiment was not a successful one, but it threw some new light on the relationship between the listening habits and playlist generation.