警卫和保洁两用机器人

日本中央安全巡逻公司与富士重工联合开发了一种无人操纵的升降型警卫与保洁两用机器人系统。 该机器人系统是一个划时代的系统,它是将警卫任务功能加到了富士重工的无人操纵的保洁机器人Ｒｏｂｏｈｉｔｅｒ中,通过加入具有升降功能的联动装置,使这种无人操纵的保洁机器人能靠自己的动力沿着办公楼的楼梯前进清洁地面,并同时执行警卫任务。用这种保洁机器人执行夜间的保卫任务,可以大大削减保卫系统的费用。 这种警卫与保洁机器人的尺寸为 ８５０ × ７２０×８９０ｍｍ,重１３５公斤（包括电池）。用一组充电电池可连续执行３小时的…     

让搜狗音乐盒边听边下

搜狗音乐盒是个不错的播放工具,不过笔者在使用它时遇到这样一个问题:在线收听网络音乐时,《搜狗音乐盒》不会自动将收听过的歌曲下载到本地硬盘中,如果需要下载的话,还需手动操作,实在麻烦,其实要解决这个问题非常简单,设置一下就行。     

An aging model for surface acoustic wave devices

The authors present a study of the phase-aging kinetics of a 591.2 MHz quartz-crystal surface acoustic wave (SAW) filter intended for application in an undersea telecommunication system. At aging temperatures from 50 to 140 degrees C, a previously established SAW-device aging model describes the time dependence of the phase aging. The results of an investigation of the temperature dependence of the coefficients in this aging model allows the authors to extend the model, capturing both the time and the temperature dependence of the degradation. They then identify and assess the sources of variation, or error, affecting the data and model, estimate the distributions of the errors, and incorporate these error distributions in the extended aging model. This leads to a composite aging model that describes the time and temperature dependence of the complete phase-aging distribution. The authors use this composite model to predict end-of-life phase-aging distributions, demonstrating that the devices exhibit the high level of stability required by the application.     

On the comparison of conceptual clustering and numerical taxonomy

Conceptual clustering requires that clusters formed in the process shall be definable in terms of simple formulas in the predicate calculus. Michalski and Stepp [1] have argued that the results obtained with this method are clearly superior to traditional methods of numerical classification, so that an order of magnitude degradation in performance is acceptable. In this paper the results and comparisons presented by Michalski and Stepp are reviewed and shown to be less than adequate to support such a conclusion. There are considerable problems with data coding and standardization, as well as choice of similarity measure, that make the results difficult to evaluate. Even accepting the clusters, two different valorizing schemes are used to evaluate the results obtained. In addition, the traditional agglomerative algorithm employed in numerical classification procedures can be adapted to perform conceptual clustering without an enormous degradation in performance. However, the value of the method can only be regarded as unproven.     

The effect of synchronization on the interpretation of flashing lamp displays

The question of whether all the lamps on a display indicating the same state should flash in phase with each other or independently is of interest to display designers. A randomized groups experiment was carried out to answer this question. It was found that a synchronized display was interpreted more quickly and with fewer errors than a display with independently flashing lamps.     

The effect of feedback on keying performance

The introduction of new telephone signalling systems and new technologies for telephone keypads has stimulated interest in the effect of providing electronic feedback on keying performance. An experiment using a conventional keypad is reported which shows that electronic auditory feedback had no significant effect on keying speed, accuracy or subject's opinion. A further series of experiments investigating the best type of feedback to improve performance with ‘touch’ keypads is then described. It was found that an electronic tone presented through the telephone earpiece was the best feedback.

Finally, performance with two types of touch keyphones incorporating the optimum form of feedback was compared with performance using a conventional keyphone. It was found that accuracy was significantly greater with the conventional keyphone, although performance with the touch keypads could be improved by electronically removing some of the very short spurious signalling times produced by them.