智能手机:谁主沉浮?

2004年手机市场中智能手机将大放光芒!林林总总的智能手机，谁将成为这场战争的主角。立于不败之地．成为真正的王者．我们拭目以待。     

智能手机:谁主沉浮?

2004年手机市场中智能手机将大放光芒!林林总总的智能手机,谁将成为这场战争的主角,立于不败之地,成为真正的王者,我们拭目以待。王者之剑联想智旋ET560ET560可通过业界首创的180°旋转折叠屏实现掌上PDA模式、手机模式、数码像机模式的自由切换。在商务功能表现上,基于微软Win鄄dowsMobile2003操作系统PocketPC电话版的ET560内置Word、Excel、Outlook等多种用户熟悉的办公软件,并可通过USB、蓝牙等方式与PC实现连接,用户还可以通过GPRS轻松实现无线上网。这款手机已经以7860元的高价在北京上市,那为什么这款手机引起了进军3G的…     

Kindle Fire vs.Nook Tablet:应该选择谁?

平板电脑有些人想买平板电脑——还得是便宜的。对于囊中羞涩的消费者来说,可供选择的主要有定价200美元的亚马逊KindIe Fire和250美元的Barnes&NobIeNook平板电脑。为了能让各自的平板电脑价格宜人,亚马逊和Barnes&Noble都做出了不少牺牲,所以它们在功能     

手机导航:On-Board与Off-Board谁主沉浮?

导航的未来是否走向手机导航,这个问题务须回答,因为没有人敢怀疑中国人手中4亿部手机的力量。而手机导航的未来是走向On-Board还是Off-Board?这个问题就没有那么容易了。人们可以轻松地举出很多Off-Board方案的优势:1、得到运营商支持,2、及时的地图更新3、价格低廉4、与其他LBS的快速整合。回想去年联通手机导航上市的号角是多么令人鼓舞,而现在我们惊奇地发现她已经难觅踪迹;移动的手机地图业务在“静悄消”式地推进,盼望中的A-GPS应用更是“只闻楼梯响,不见人下来”。这不由得让我们对那些轻松得到的判断打下大大的问号。     

XP vs.Vista:谁是最好的Windows

微软认为你的下一台电脑的操作系统应该是Windows Vista,如果你还有选择的自由的话,也许你的选择与微软的期望会不同。     

2000年:中国IT市场谁主沉浮(上)

1999年12月29日,国家统计局最新发布的预测显示,我国国内生产总值全年将达83190亿元,比1998年增长7.1%。这表明,我国已如期实现年初既定经济增长目标。国家发展计划委员会则预测我国经济在2000年将达到8％的增长率。而1999年12月26日,美国经济评议会在纽约发表的一项分析报告也认为,中国经济未来的增长率为8%,同时如果中国在2000年加入世贸组织,经济成长率应可望提高至10%。在这样的大背景下,从政府到民间对中国信息产业的未来发展都保持着相当乐观的态度。岁末年初,根据记者从信息产业部,市场研究机构乃至一些业界厂商所了解到的数据资料及市场信息,本文将着重分析中国IT市场1999年发展概况和2000年令人关注的热点问题。面对明星辈出的产品家族、变幻莫测的市场风云,有限的篇幅难以包容所有领域的最新进展,今天的预言很快也可能成为明日黄花,但是IT世界的的浩瀚无边和难以预测也正是它的魅力所在。     

2000年:中国IT市场谁主沉浮(下)

网络市场增长迅速 1999年在上海“财富全球论坛”活动期间,信息产业部部长吴基传曾预测2003年中国互联网用户总数将达到2000万,而中科院院长路甬祥提出了一个更为大胆的预测数字——3700万。据IDC的最新统计,1999年底,中国Internet用户总数将达到379万     

Computer- vs. paper-based tasks: Are they equivalent?

In 1992, Dillon published his critical review of the empirical literature on reading from paper vs. screen. However, the debate concerning the equivalence of computer- and paper-based tasks continues, especially with the growing interest in online assessment. The current paper reviews the literature over the last 15 years and contrasts the results of these more recent studies with Dillon's findings. It is concluded that total equivalence is not possible to achieve, although developments in computer technology, more sophisticated comparative measures and more positive user attitudes have resulted in a continuing move towards achieving this goal. Many paper-based tasks used for assessment or evaluation have been transferred directly onto computers with little regard for any implications. This paper considers equivalence issues between the media by reviewing performance measures. While equivalence seems impossible, the importance of any differences appears specific to the task and required outcomes.     

Computer- vs. paper-based tasks: are they equivalent?

In 1992, Dillon published his critical review of the empirical literature on reading from paper vs. screen. However, the debate concerning the equivalence of computer- and paper-based tasks continues, especially with the growing interest in online assessment. The current paper reviews the literature over the last 15 years and contrasts the results of these more recent studies with Dillon's findings. It is concluded that total equivalence is not possible to achieve, although developments in computer technology, more sophisticated comparative measures and more positive user attitudes have resulted in a continuing move towards achieving this goal. Many paper-based tasks used for assessment or evaluation have been transferred directly onto computers with little regard for any implications. This paper considers equivalence issues between the media by reviewing performance measures. While equivalence seems impossible, the importance of any differences appears specific to the task and required outcomes.     

争论:以索尼PSP为代表的新兴便携式掌上游戏设备,值得购买吗?

作为新兴便携式掌上游戏设备的代表,PSP又被索尼称为21世纪的Walkman,它并不只是一部纯粹的游戏机,同时也是一部便携影音播放机。新型的掌上游戏设备将不仅仅限于游戏功能,以PSP来进行说明的话,你可以用它来看电影、听音乐和玩游戏,随时随地享受高品质的娱乐生活。从性能上来说,PSP拥用频     

.NETvs.J2EE:谁与争锋?

2005年,开发平台可谓热闹非凡,重量级的软件公司纷纷推出新的开发平台和开发工具。主打.NET的微软公司在2005年第4季度,隆重推出了酝酿已久的VisualStu-dio2005及其相关的软件。其发布活动将在全球90多个国家先后举行,并且在国内巡展了20个城市,其宣传力度之大前所未有。可见微     

Depth from Defocus vs. Stereo: How Different Really Are They?

Depth from Focus (DFF) and Depth from Defocus (DFD) methods are theoretically unified with the geometric triangulation principle. Fundamentally, the depth sensitivities of DFF and DFD are not different than those of stereo (or motion) based systems having the same physical dimensions. Contrary to common belief, DFD does not inherently avoid the matching (correspondence) problem. Basically, DFD and DFF do not avoid the occlusion problem any more than triangulation techniques, but they are more stable in the presence of such disruptions. The fundamental advantage of DFF and DFD methods is the two-dimensionality of the aperture, allowing more robust estimation. We analyze the effect of noise in different spatial frequencies, and derive the optimal changes of the focus settings in DFD. These results elucidate the limitations of methods based on depth of field and provide a foundation for fair performance comparison between DFF/DFD and shape from stereo (or motion) algorithms.     

Cognitive load theory vs. constructivist approaches: which best leads to efficient,deep learning?

Computer‐assisted learning, in the form of simulation‐based training, is heavily focused upon by the military. Because computer‐based learning offers highly portable, reusable, and cost‐efficient training options, the military has dedicated significant resources to the investigation of instructional strategies that improve learning efficiency within this environment. In order to identify efficient instructional strategies, this paper investigates the two major learning theories that dominate the recent literature on optimizing knowledge acquisition: cognitive load theory (CLT) and constructivism. According to CLT, instructional guidance that promotes efficient learning is most beneficial. Constructivist approaches, in contrast, emphasize the importance of developing a conceptual understanding of the learning material. Supporters of these theories have debated the merits and shortcomings of both positions. However, in the absence of consensus, instructional designers lack a well‐defined model for training complex skills in a rapid, efficient manner. The current study investigates the relative utility of CLT and constructivist‐based approaches for teaching complex skills using a military command and control task. Findings suggest that the acquisition of procedural, declarative, and conceptual knowledge, as well as decision‐making skills, did not differ as a function of the type of instruction used. However, integrated knowledge was slightly better retained by the group provided with CLT‐based instruction. These results are contrary to our expectation that constructivist approaches, which focus on the development and integration of information, would yield better performance in an applied problem‐based environment. Thus, while contemporary researchers continue to defend the use of constructivist strategies for teaching, our research supports earlier findings that question the utility, efficiency, and impact of these strategies in applied domains.     

百家邮箱(www.email.com.cn)故事“呆呆与胖妞”之三我是谁?

呆呆刚刚买了电脑,不用再花许多钱去泡网吧,因此天天下了班便疯狂地往家跑。那天,他掉进了刚施工完还没盖上盖的井里……施工单位支付了足够的住院治疗费,又赔偿给呆呆一笔数目可观的钱,但呆呆无论如何也想不起自己是谁、家住哪里。偏偏他也没带任何证件,他现在只能以医院为家。呆呆失忆了! 伤已经基本养好,呆呆嫌病房里闷,到街上闲逛;见一位姑娘使劲冲他这边喊:“呆呆,呆呆!”呆呆左右看了看,没有别人答应,心想:这姑娘倒是依稀有些面熟。那姑娘就是胖妞。几天没有呆呆的任何消息,胖妞正想去呆呆家找他,没想到在街上碰到。可呆呆对她居然不理不睬!