“Graphical” Jogthrough: expert based methodology for user interface evaluation, applied in the case of an educational simulation interface

“Walkthrough” and “Jogthrough” techniques are well known expert based methodologies for the evaluation of user interface design. In this paper we describe the use of “Graphical” Jogthrough method for evaluating the interface design of the Network Simulator, an educational simulation program that enables users to virtually build a computer network, install hardware and software components, make the necessary settings and test the functionality of the network. Graphical Jogthrough is a further modification of a typical Jogthrough method, where evaluators' ratings produce evidence in the form of a graph, presenting estimated proportion of users who effectively use the interface versus the time they had to work with it in order to succeed effectiveness. We comment on the question: “What are the possible benefits and limitations of the Graphical Jogthrough method when applied in the case of educational software interface design?” We present the results of the evaluation session, and concluding from our experience we argue that the method could offer designers quantitative and qualitative data for formulating a useful (though rough in some aspects) estimation about the novice–becoming–expert pace that end users might follow when working with the evaluated interface.     

基于ASP技术的用户登录系统的实现

在Internet上进行网页浏览时,随处可见用户的登录界面,为了防止一些非法用户登录网站并破坏网站,一般的网站都设置用户登录系统来验证用户的身份,这样可以有效地防止非法用户登录网站,提高网站的安全性。以用ASP技术开发的“用户登录系统”为例,介绍设计构思、实现、数据安全等内容。     

基于ASP技术的用户登录系统的实现

在Internet上进行网页浏览时,随处可见用户的登录界面,为了防止一些非法用户登录网站并破坏网站,一般的网站都设置用户登录系统来验证用户的身份,这样可以有效地防止非法用户登录网站,提高网站的安全性。以用ASP技术开发的"用户登录系统"为例,介绍设计构思、实现、数据安全等内容。     

结合Web站点结构的路径补充

服务器端保存的Web访问日志含有大量的用户浏览信息,因此有效地利用该资源可以挖掘出有用的信息,并能得到用户个人的访问模式,从而为改善站点结构提供了支持。在结合站点拓扑结构的基础上,针对Web日志挖掘数据预处理过程中的路径补充提出了最短向后父节点算法(SBFN)。研究表明该算法能够对Web日志中的用户访问路径进行补充,从而为解决站点结构优化问题提供了方案。     

Using the Semantic Web for linking and reusing data across Web 2.0 communities

Large volumes of content (bookmarks, reviews, videos, etc.) are currently being created on the “Social Web”, i.e. on Web 2.0 community sites, and this content is being annotated and commented upon. The ability to view an individual's entire contribution to the Social Web would be an interesting and valuable service, particularly important as social networks are often being formed through created content and things that people have in common (“object-centred sociality”). SIOC is a Semantic Web research project that aims to describe online communities on the Social Web. This paper describes how SIOC and the Semantic Web can enable linking and reuse scenarios of data from Web 2.0 community sites, and introduces a SIOC Types module to further specify the type of content items and act as a “glue” between user posts and the content items created and annotated by users.     

一种预测群体用户访问行为的算法

在电子商务发展中,商家需要理解用户访问网站的行为,为用户提供个性化服务,从而吸引用户购买商品。挖掘用户访问网站的行为是商家一个急需解决的问题,通过对Web日志进行挖掘是解决该问题的重要研究方法。提出了网页兴趣信息素的新概念,它是由页面相对浏览时间和点击率构建而成,利用兴趣信息素设计了基于蚁群算法的群体用户访问路径挖掘算法,根据挖掘结果预测用户访问行为。实验结果表明,兴趣信息索可以有效地预测用户的兴趣变化,能准确地反映用户访问模式,提高了预测群体用户访问行为的准确率。     

FLASK-SG: A program to compute chemical equilibria in metamorphic petrology

Chemical equilibrium calculation program for metamorphic petrology, FLASK-SG, was written for Unix variants (Linux, IRIX, Tru64 UNIX). It is also ported to Windows 95/98. The user specifies a temperature, pressure, and substance amounts (in moles of any chemical formula in C–H–O–Si–Al–Ti–Fe–Mn–Mg–Ca–Na–K system) to this program, then it calculates the stable mineral assemblage, mineral amounts, and gas composition under the given conditions using Gibbs free energy minimization method with the Holland and Powell (1990) data set. Searching algorithm for the stable mineral assemblage is the Metropolis Monte Carlo method. The coding language is C++, and experimental object oriented programming style is adopted to make the main program part as a class library. Model-dependent functions such as fugacity coefficients and activities are implemented as virtual methods of the “systems” class, so they can be easily changed as methods of inherited class from the “systems” class. These characteristics are aimed for a future “simulation kit”.     

SweetWiki: A semantic wiki

Everyone agrees that user interactions and social networks are among the cornerstones of “Web 2.0”. Web 2.0 applications generally run in a web browser, propose dynamic content with rich user interfaces, offer means to easily add or edit content of the web site they belong to and present social network aspects. Well-known applications that have helped spread Web 2.0 are blogs, wikis, and image/video sharing sites; they have dramatically increased sharing and participation among web users. It is possible to build knowledge using tools that can help analyze users’ behavior behind the scenes: what they do, what they know, what they want. Tools that help share this knowledge across a network, and that can reason on that knowledge, will lead to users who can better use the knowledge available, i.e., to smarter users. Wikipedia, a wildly successful example of web technology, has helped knowledge-sharing between people by letting individuals freely create and modify its content. But Wikipedia is designed for people—today's software cannot understand and reason on Wikipedia's content. In parallel, the “semantic web”, a set of technologies that help knowledge-sharing across the web between different applications, is starting to gain attraction. Researchers have only recently started working on the concept of a “semantic wiki”, mixing the advantages of the wiki and the technologies of the semantic web. In this paper we will present a state-of-the-art of semantic wikis, and we will introduce SweetWiki, an example of an application reconciling two trends of the future web: a semantically augmented web and a web of social applications where every user is an active provider as well as a consumer of information. SweetWiki makes heavy use of semantic web concepts and languages, and demonstrates how the use of such paradigms can improve navigation, search, and usability.     

Let's browse: a collaborative browsing agent

Web browsing, like most of today's desktop applications, is usually a solitary activity. Other forms of media, such as watching television, are often done by groups of people, such as families or friends. What would it be like to do collaborative Web browsing? Could the computer provide assistance to group browsing by trying to help find mutual interests among the participants? Let's Browse is an experiment in building an agent to assist a group of people in browsing, by suggesting new material likely to be of common interest. It is built as an extension to the single user Web browsing agent Letizia. Let's Browse features automatic detection of the presence of users, automated “channel surfing” browsing, and dynamic display of the user profiles and explanation of recommendations.     

Control design for recycled, multi unit processes

An integrated multi-unit chemical plant presents a challenging control design problem due to the existence of recycling streams. In this paper, we develop a framework for analyzing the effects of recycling dynamics on closed-loop performance from which a systematic design of a decentralized control system for a recycled, multi-unit plant is established. In the proposed approach, the recycled streams are treated as unmodelled dynamics of the “unit” model so that their effects on closed-loop stability and performance can be analyzed using the robust control theory. As a result, two measures are produced: (1) the ν-gap metric, which quantifies the strength of recycling effects, and (2) the maximum stability margin of “unit” controller, which represents the ability of the “unit” controller to compensate for such effects. A simple rule for the “unit” control design is then established using the combined two measures in order to guarantee the attainment of good overall closed-loop performances. As illustrated by several design examples, the controllability of a recycled, multi unit process under a decentralized “unit” controller can be determined without requiring any detailed design of the “unit” controller because the simple rule is calculated from the open-loop information only.     

A decade of progress in iterative process control design: from theory to practice

One of the most active areas of research in the nineties has been the study of the interplay between system identification and robust control design. It has led to the development of “control-oriented identification design”, the paradigm being that, since the model is only a tool for the design of a controller, its accuracy (or its error distribution) must be tuned towards the control design objective. This observation has led to the concept of “iterative identification and control design” and, subsequently, to model-free iterative controller design, in which the controller parameters are iteratively tuned on the basis of successive experiments performed on the real plant, leading to better and better closed-loop behaviour. These iterative methods have found immediate applications in industry; they have also been applied to the optimal tuning of PID controllers. This paper presents the progress that has been accomplished in iterative process control design over the last decade. It is illustrated with some applications in the chemical industry.     

A multilingual knowledge management system: A case study of FAO and WAICENT

This paper provides a case study of a multilingual knowledge management system for a large organization. In so doing we elicit what it means for a system to be “multilingual” and how that changes some previous research on knowledge management. Some researchers have viewed multilingual as meaning a multilingual user interface. However, that is only a small part of the story. In this case we find multilingual also refers to a broad range of “multilingual,” including multilingual knowledge resources, multilingual feedback from users, multilingual search, multilingual ontologies and other concerns.     

Perceptual control and layered protocols in interface design: II. The general protocol grammar

Perceptual control theory (PCT) is a framework theory for psychology, based on the tenet “All behaviour is the control of perception.” Layered protocol theory (LPT) is PCT applied to the special case of communication between cooperating partners, each controlling their own perceptions and many levels of abstraction within a dialogue. This paper discusses some perceptual control processes that occur within a single dialogue level, in the form of a General Protocol Grammar that is asserted to be valid for every level of every dialogue. A companion paper is concerned with LPT applied to the design and analysis of human–machine interfaces.     

基于用户浏览行为的个性化推荐研究综述

研究如何充分利用海量用户浏览行为数据,构建更加精确的推荐算法和模型,以提高推荐系统性能,是目前个性化推荐领域研究的热点.针对这些问题,首先对用户的浏览行为进行了简要概括表述,给出了基于浏览行为推荐系统的总体框架,回顾总结了基于用户浏览行为的推荐系统的发展历程.对其关键技术和单一浏览行为量化方法与混合浏览行为量化方法进行总结、对比和分析.最后讨论了结合多源异构数据的浏览行为推荐的最新成果,总结了该领域未来研究难点和发展趋势.     

User requirements for security in wireless mobile systems

Security of wireless mobile systems continues to be a hot topic; now generating its own conferences and platforms, such as the recent 2nd IEE Secure Mobile Communications held by the IEE on 23 September 2004. The general discussion on security in wireless systems takes place in technical fora, and while this is a totally valid discussion, it sometimes seems to be taking place in isolation. From the user perspective the wireless system usually forms part of a larger, interconnected system. This paper raises the question, “What about the user?” and offers some views on the user requirements on this most important part of system design where people are one end of the chain which involves wireless and other systems.     

The roles of sensory modalities in collaborative virtual environments (CVEs)

This study was conducted to assess the effects of sensorial modalities on user performance, perception, and behavior in collaborative virtual environments (CVEs). Participants played a CVE game, air hockey, together with a remote partner under different sensory modality conditions, depending on the type of sensory feedback provided: visual-only (V), visual–haptic (V + H), and visual–haptic–audio feedback (V + H + A). Three types of measurements were used as dependent variables: (1) task performance measured as playing time, (2) user perception including the sense of presence, the sense of togetherness, and perceived collaboration, and (3) behavior measurement including the amount of force applied and the mallet deviation. Results of the study indicated that the task performance, perception, and user behavior in CVEs can be affected due to supported sensory modalities. Therefore, the multiple sensory information types that are required to perform the task at hand should be provided to effectively support collaboration between people in CVEs. The outcomes of this research should have a broad impact on multimodal user interaction, including research on physiological, psychophysical, and psychological mechanisms underlying human perception on multisensory feedback in CVEs.     

Adaptation of maximum entropy capitalizer: Little data can help a lot

A novel technique for maximum “a posteriori” (MAP) adaptation of maximum entropy (MaxEnt) and maximum entropy Markov models (MEMM) is presented.The technique is applied to the problem of automatically capitalizing uniformly cased text. Automatic capitalization is a practically relevant problem: speech recognition output needs to be capitalized; also, modern word processors perform capitalization among other text proofing algorithms such as spelling correction and grammar checking. Capitalization can be also used as a preprocessing step in named entity extraction or machine translation.A “background” capitalizer trained on 20 M words of Wall Street Journal (WSJ) text from 1987 is adapted to two Broadcast News (BN) test sets – one containing ABC Primetime Live text and the other NPR Morning News/CNN Morning Edition text – from 1996.The “in-domain” performance of the WSJ capitalizer is 45% better relative to the 1-gram baseline, when evaluated on a test set drawn from WSJ 1994. When evaluating on the mismatched “out-of-domain” test data, the 1-gram baseline is outperformed by 60% relative; the improvement brought by the adaptation technique using a very small amount of matched BN data – 25–70k words – is about 20–25% relative. Overall, automatic capitalization error rate of 1.4% is achieved on BN data.The performance gain obtained by employing our adaptation technique using a tiny amount of out-of-domain training data on top of the background data is striking: as little as 0.14 M words of in-domain data brings more improvement than using 10 times more background training data (from 2 M words to 20 M words).     

Efficient constrained local model fitting for non-rigid face alignment

Active appearance models (AAMs) have demonstrated great utility when being employed for non-rigid face alignment/tracking. The “simultaneous” algorithm for fitting an AAM achieves good non-rigid face registration performance, but has poor real time performance (2–3 fps). The “project-out” algorithm for fitting an AAM achieves faster than real time performance (>200 fps) but suffers from poor generic alignment performance. In this paper we introduce an extension to a discriminative method for non-rigid face registration/tracking referred to as a constrained local model (CLM). Our proposed method is able to achieve superior performance to the “simultaneous” AAM algorithm along with real time fitting speeds (35 fps). We improve upon the canonical CLM formulation, to gain this performance, in a number of ways by employing: (i) linear SVMs as patch-experts, (ii) a simplified optimization criteria, and (iii) a composite rather than additive warp update step. Most notably, our simplified optimization criteria for fitting the CLM divides the problem of finding a single complex registration/warp displacement into that of finding N simple warp displacements. From these N simple warp displacements, a single complex warp displacement is estimated using a weighted least-squares constraint. Another major advantage of this simplified optimization lends from its ability to be parallelized, a step which we also theoretically explore in this paper. We refer to our approach for fitting the CLM as the “exhaustive local search” (ELS) algorithm. Experiments were conducted on the CMU MultiPIE database.     

A test-first view of usability

The foundations of usability evaluation were being established in the early 1990s. In this context, “Usability – Context, Definition, Design and Evaluation” built upon Brian Shackel’s earlier influential work – work that helped define the notion of usability. In this paper, he established key dimensions of usability as well as approaches to integrating the testing of these dimensions, within the whole process of setting requirements. Essentially he argued for usability design as part of the system design process.This commentary describes the context of Professor Shackel’s paper and reviews the influential ideas that appear in much subsequent work.     

Speech enhancement based on undecimated wavelet packet-perceptual filterbanks and MMSE–STSA estimation in various noise environments

In this paper, we proposed a new speech enhancement system, which integrates a perceptual filterbank and minimum mean square error–short time spectral amplitude (MMSE–STSA) estimation, modified according to speech presence uncertainty. The perceptual filterbank was designed by adjusting undecimated wavelet packet decomposition (UWPD) tree, according to critical bands of psycho-acoustic model of human auditory system. The MMSE–STSA estimation (modified according to speech presence uncertainty) was used for estimation of speech in undecimated wavelet packet domain. The perceptual filterbank provides a good auditory representation (sufficient frequency resolution), good perceptual quality of speech and low computational load. The MMSE–STSA estimator is based on a priori SNR estimation. A priori SNR estimation, which is a key parameter in MMSE–STSA estimator, was performed by using “decision directed method.” The “decision directed method” provides a trade off between noise reduction and signal distortion when correctly tuned. The experiments were conducted for various noise types. The results of proposed method were compared with those of other popular methods, Wiener estimation and MMSE–log spectral amplitude (MMSE–LSA) estimation in frequency domain. To test the performance of the proposed speech enhancement system, three objective quality measurement tests (SNR, segSNR and Itakura–Saito distance (ISd)) were conducted for various noise types and SNRs. Experimental results and objective quality measurement test results proved the performance of proposed speech enhancement system. The proposed speech enhancement system provided sufficient noise reduction and good intelligibility and perceptual quality, without causing considerable signal distortion and musical background noise.