便携系统的用户接口设计

有许多方法从一个计算机平台输入或输出信息。在大多数情况下是由应用来决定什么是最适合的用户接口方式。选择的范围可以是标准键盘或小型键盘、光笔、触摸屏,甚至是语音输入。还包括和机器集成在一起的点击式输入设备,如触摸垫（touch pad）、小型鼠标、点击棒（pointing stick）等。将来,也许会有其他更有趣的设备。决定选择这些方法的主要因素是成本和接口的方式。如果成本不是一个主要考虑的因素,那么,几乎所有的接口方式都可以被选用。语音识别应该是最难实现的一种输入方式,但如果不考虑成本,则可以极大地提高处理器的处理能…     

电子图书设计初探

高技术让我们生活得更舒适.所有这些新技术发明是对有用的老式技术的改进.以PDA为例,我个人认为,它的确超越了过时的记事簿.     

Tribocorrosion and corrosion behavior of stainless steel coated with DLC films in ethanol with different concentrations of water

There has been a recent increase in both the production and consumption of ethanol due to the numerous environmental advantages that it offers, such as the fact that it can be produced from a variety of renewable materials, for instance corn and cellulose, or it can be obtained from sugarcane bagasse and biomass (2nd and 3rd generation ethanol). The result of this is that nowadays ethanol is widely seen as the dominant biofuel – or as a blend component in gasoline or pure fuel - in many countries.However, one disadvantage of the use of ethanol is the high corrosive behavior that occurs when its hygroscopic properties are exposed to a large number of materials. Xiaoyuan Lou and Preet Singh showed that the increase of water concentration in ethanol induces pitting and metal loss. Diamond-Like Carbon (DLC) films may be a solution to this problem due to the fact that they can be deposited inside tubes, offer good protection levels against corrosion, and reduce the friction coefficient and wear.This paper shows the tribocorrosion and corrosion studies of DLC films deposited on stainless steel grade 304 (SS304) substrates in order to gauge its appropriateness usage in the construction of pipelines and fuel storage tanks. The surface morphology was analyzed before and after 14 days of immersion. The tribocorrosion, friction coefficient, and wear rate were studied in ethanol to see the effects of water concentration. The films showed good adherence to the substrates. Corrosion and tribocorrosion results showed that for bare Stainless Steel 304 the increase of the water content increases the corrosion and the friction coefficient. DLC coated samples presented few points of delamination, and the friction coefficient and open circuit potentials were very low compared with the bare sample which was water concentration independent.     

Schedule of Events

In this study, the effect of the user choice on social responses to computer-synthesized speech is investigated. Three previous findings about social responses to computer-synthesized speech (i.e., social identification, proximate source orientation, and similarity attraction) were tested using the choice paradigm. Social identification and proximate source orientation effects were found even when users had chosen a computer voice at their discretion. In addition, the primacy effect in the user choice prevailed: Participants were more likely to select whatever voice that they heard first between two options. The similarity attraction effect, however, was negated by the cognitive dissonance effect after user choices. The robustness of social responses, its implications for human–computer interaction, and the importance of the user choice in voice-interface designs are discussed.     

Anthropocentrism and computers

This paper introduces the multi-dimensional concept of anthropocentrism with respect to computers, the tendency to believe that (1) computers do not possess human physical and psychological capabilities; and (2) it is not acceptable for computers to fill routinized (e.g., auto mechanic), interpretive (e.g., newspaper reporter), and persona) (e.g., baby sitter) roles traditionally held only by people. A mail survey (n = 133) of individuals in Northern California focuses on individual differences rather than differences between technologies. As suggested by the literature on ethnocentrism, experience with other cultures and education are strong predictors of the dimensions of anthropocentrism; surprisingly, experience with computers fails as a predictor.     

Intracellular sequestration of sodium by a novel Na+/H+ exchanger in yeast is enhanced by mutations in the plasma membrane H+-ATPase. Insights into mechanisms of sodium tolerance

Sodium tolerance in yeast is disrupted by mutations in calcineurin, a Ca2+/calmodulin-dependent protein phosphatase, which is required for modulation of Na+ uptake and efflux mechanisms. Five Na+-tolerant mutants were isolated by selecting for suppressors of calcineurin mutations, and mapped to the PMA1 gene, encoding the plasma membrane H+-ATPase. One mutant, pma1-alpha4, which has the single amino acid change Glu367 --> Lys at a highly conserved site within the catalytic domain of the ATPase, was analyzed in detail to determine the mechanism of Na+ tolerance. After exposure to Na+ in the culture medium, 22Na influx in the pma1 mutant was reduced 2-fold relative to control, consistent with a similar decrease in ATPase activity. Efflux of 22Na from intact cells was relatively unchanged in the pma1 mutant. However, selective permeabilization of the plasma membrane revealed that mutant cells retained up to 80% of intracellular Na+ within a slowly exchanging pool. We show that NHX1, a novel gene homologous to the mammalian NHE family of Na+/H+ exchangers, is required for Na+ sequestration in yeast and contributes to the Na+-tolerant phenotype of pma1-alpha4.     

分立逻辑器件何去何从

分立逻辑功能合并的趋势随处可见，很久以前就出现了芯片组，而且这一技术还在发展。一般说来，设计师想极力摆脱分立逻辑，但历史经验告诉我们，人们将不可能完全摒弃逻辑器件。市场调研表明：前年，逻辑产品的全部有效市场额度（TAM）为24亿美元。如果按工艺技术划分的话，CMOS逻辑占18.7亿美元，其次是BiCMOS，为3.05亿美元，而TTL（包括最早的双极工艺）为3.09亿美元。有朝一日会实现集成化确实，只要有可能，分立逻辑功能已被并入在其它器件中，如母板上的芯片组中。但对某些功能，还是需要分立逻辑。一个重要原因是，随着速度和…     

The development of drawing in children with congenital focal brain injury: evidence for limited functional recovery

Children with pre- or perinatal injury to right hemisphere (RH) brain regions show impairment of spatial integrative functions similar to that observed among adults with comparable injury. Unlike adults, children show considerable improvement with development on a range of spatial construction tasks which require spatial integration. Such gains could reflect true recovery of spatial integrative abilities. Alternatively, the improvement could be more limited in scope, reflecting the development of compensatory strategies which are task specific and allow the children to circumvent, rather than overcome, their primary spatial disorders. The studies presented here examined this distinction within the context of drawing tasks in which the child was first asked to draw a house and then an impossible house. The impossible house task was designed to examine the extent to which children rely on graphic formulas in generating organized drawings. The results showed that while all of the children with RH injury make considerable progress in free drawing into the school age period, they are very reliant on the use of graphic formulas. When given a task which requires them to alter their drawings, they did not change the spatial configuration of the depicted object. Rather they found alternate ways to render the object 'impossible'.     

选择恰当的便携系统总线

在便携系统中,从点Ａ到点Ｂ传 送数据有很多方法。第一个要回答的问题是,点Ａ和点Ｂ表示什么？第二个要回答的是信息是从主处理器到存储器（或到电池供电子系统）或者是另外其他目的地？ 在数据从处理器（或微控制器）传输到存储器（如串行ＥＥＰＲＯＭ）的最普通实例中,典型的传输媒体有三种类型：串行外设接口（ＳＰＩ）、ＩｎｔｅｒＩＣ（Ｉ２Ｃ）和 ＭｉｃｒｏＷｉｒｅ。 串行接口 ＳＰＩ开始由Ｍｏｔｏｒｏｌａ公司开发,是设计作为该公司微控制器系列的接口。其后,ＳＰＩ已变成某种行业标准。 ＳＰＩ是一种同步串行数据协议,它支…     

节省便携系统功率的设计思考

蜂窝电话是迅速发展的一个市场领域,预测明年可增长到２．５亿部;到２００３年可达５亿部。面对如此巨大的市场,制造商们尽全力使产品完备无缺,用某些关键指标使产品优于竞争对手。节省便携系统中每个部分的功率至关重要。例如,若ＣＰＵ功耗为４Ｗ,则降低２５％可节省１Ｗ,这对于由一对ＡＡ电池供电的手持装置意义尤其重大。设计人员千方百计节省可能节省的每一ｍＷ,如果使键盘控制器耗电从１０ｍＡ降到８ｍＡ,则可节省６．６ｍＷ（使用３．３Ｖ电源）。在蜂窝电话和计算机中能节省功率的产品是大不相同的,尽管它们的目的都是延长…