基于原型设计的人机交互课程实验方案

人机交互课程是实践性很强的一门课。实验是人机交互课程的重要组成部分。现阶段,国内高校的人机交互课程的学时数普遍不多。没有足够的学时造成无法通过软件开发项目实战来开展人机交互设计实践。一种对策是开展软件界面原型设计实验。描述基于原型设计的人机交互课程实验方案。首先描述了实验目的,接着描述实验任务和目标,再接着重点描述了实验流程,然后描述实验成果验收的办法。最后总结了该实验方案的优势和面临的问题。     

Social interaction in online support groups: Preference for online social interaction over offline social interaction

The purpose of the current study was to identify potential factors leading to preference for social interaction in online support groups (OSGs) over offline interaction. By identifying such factors, the current study advances understanding of the way patients use the Internet as a supportive resource and integrate support from offline and online relationships. An online survey was conducted with current users of health-related OSGs (N = 158). Findings show that those who were dissatisfied with the support they received from their current offline contacts were more likely to prefer social interaction in OSGs. Such a preference was prominent among those who built deeper social relationships in OSGs. Results suggest that some people develop a preference for social interaction in OSGs over offline interaction and use computer-mediated relationships as a possible alternative to offline support networks. Healthcare professionals and users as well as designers of OSGs must acknowledge the limits of online support and caution against the possibility of developing excessive reliance on online support resources.     

改进模糊层次分析法及其对任务方案的评价

对于复杂环境中任务方案的评价,由于涉及的因素众多使得评价指标不易全面,文中给出了一种层次化的指标体系,通过准则层细化出子准则层使评价指标全面化。加之对模糊层次分析法的改进,使得上述指标体系层次数目可以不受限制,层次数增加而相应计算量增加却不大;并且通过改换算法中常用的计算因素权值的公式,提高了方案评价的分辨率,增加了对方案优选结果的可信程度。     

计算机仿真系统评估方案研究

分布式交互是实现复杂系统仿真的重要手段,各个成员仿真系统的性能至关重要,现有评估方法主要关注于仿真系统、模型的正确性和可信度,而没有从全面综合的角度来分析仿真系统自身的质量。因此,建立了能够整体评估仿真系统性能的指标体系,构建了仿真系统二级模糊综合评估模型,并应用该模型对野营保障模拟训练系统进行了评估分析,得出了较为合理的评估结论,验证了评估方案的可行性和易操作性。     

A stable time advancing scheme for solving fluid-structure interaction problem at small structural displacements

A semi-implicit time advancing scheme for transient fluid-structure interaction problem is presented. At every time step, a least squares problem is solved by partitioned procedures, such that the continuity of the velocity as well as the continuity of the stress hold at the interface. During the iterative method for solving the optimization problem, the fluid mesh does not move, which reduces the computational effort. The stability of the algorithm is derived. The numerical results presented in this paper show that the computed solution is similar to the one obtained by the implicit algorithm, but the computational time is reduced.     

Online bin packing with arbitrary release times

We study a new variant of the online bin-packing problem, in which each item _ai$a_i$ is associated with a size _ai$a_i$ and also a release time _ri$r_i$ so that it must be placed at least _ri$r_i$ above the bottom of a bin. Items arrive in turn and must be assigned without any knowledge of subsequent items. The goal is to pack all items into unit-size bins using the minimum number of bins. We study the problem with all items have equal size. First, we show that the ANY FIT algorithm cannot be approximated within any constant. Then we present a best possible online algorithm with asymptotic competitive ratio of two.     

体感交互虚拟漫游的沉浸感评价

沉浸感是虚拟漫游的重要特征,目前体感交互的虚拟漫游存在严重的感知失真问 题,虚拟场景运动的视觉感知与人机交互的体感感知不能相互匹配,破坏了虚拟漫游的沉浸感。 基于Catmull-Rom 曲线的非等距插值算法、等距插值算法和实时插值算法,分别构建3 种不同 的虚拟漫游路径,评价体感交互虚拟漫游的沉浸感。主观评价实验和仿真实验的结果表明： Catmull-Rom 曲线的非等距插值漫游路径,无论是匀速漫游还是变速漫游,均存在明显的感知 失真现象;基于Catmull-Rom 曲线的等距插值漫游路径适用于匀速漫游,但不太适合用于变速 漫游;基于Catmull-Rom 曲线的实时插值漫游路径能实现真实运动速度与场景运动速度的匹配, 较好地解决虚拟漫游时视觉感知与身体运动感知不一致的问题,增强了虚拟漫游的沉浸感。     

Performance evaluation of the object-relational transformation methodology

The emergence of the object-oriented (OO) methodology has shown its capabilities in modelling the real world better than the earlier relational methodology. However, object-oriented databases (OODBs) are still considered immature in comparison with relational databases (RDBs) which have existed for many years. RDBs still continue to dominate the implementation of databases constituting more than 90% of all database implementations [28]. It was felt worthwhile to exploit the great modelling power of OO methodology, while still facilitating relational implementations. These reasons have led us to develop an object-relational transformation methodology [20, 21, 22, 23, 24 and 25] which allows us to use the OO methodology for data modelling and to transform it into a relational logical model for implementation in relational database management systems (RDBMSs). The main purpose of this paper is to present a performance evaluation of the transformation methodology. The evaluation covers I/O cost models of different types of queries. The type of evaluation is basically comparison-based, in which the performance of SQL operations upon a set of tables derived from the relational data model is compared with the tables derived from the OO data model using the transformation methodology. The results of the evaluation show that the performance of the RDB implementation transferred from an OO conceptual model using our object-relational transformation methodology is better than the relational implementation using a conventional relational modelling. Moreover, in many cases, the relational modelling is not applicable since it cannot capture the design semantics particularly relating to collection types. Our object-relational methodology solves this problem.     

A comparative workload-based methodology for performance evaluation of parallel computers

A practical methodology for evaluating and comparing the performance of distributed memory Multiple Instruction Multiple Data (MIMD) systems is presented. The methodology determines machine parameters and program parameters separately, and predicts the performance of a given workload on the machines under consideration. Machine parameters are measured using benchmarks that consist of parallel algorithm structures. The methodology takes a workload-based approach in which a mix of application programs constitutes the workload. Performance of different systems are compared, under the given workload, using the ratio of their speeds. In order to validate the methodology, an example workload has been constructed and the time estimates have been compared with the actual runs, yielding good predicted values. Variations in the workload are analysed in terms of increase in problem sizes and changes in the frequency of particular algorithm groups. Utilization and scalability are used to compare the systems when the number of processors is increased. It has been shown that performance of parallel computers is sensitive to the changes in the workload and therefore any evaluation and comparison must consider a given user workload. Performance improvement that can be obtained by increasing the size of a distributed memory MIMD system depends on the characteristics of the workload as well as the parameters that characterize the communication speed of the parallel system.     

The minimum bandwidth required at each time slot of the fast broadcasting scheme

In this paper, we show that the Fast broadcasting scheme (L.-S. Juhn and L.-M. Tseng, 1998 [4]), abbreviated the FBR scheme, is also suitable for heterogeneous clients of different communication capabilities although it is originally designed for homogeneous clients of the same bandwidth. Given α channels of total bandwidth α⋅b Mbps to deliver a video of the consumption rate b Mbps, we first show that the FBR scheme can be employed to serve clients with communication capabilities ranging from b to α⋅b Mbps. Furthermore, we propose a simple way to determine the minimum bandwidth required at any given time slot.     

基于模糊MACBETH和生态位理论的PSS方案评价方法

针对多属性决策方法与生态位理论结合的PSS评价方法权重确定过程中一致性检验繁琐、权重计算过程复杂和未考虑评价语义的模糊性的问题,模糊MACBETH用于确定客户价值的权重和客户体验阶段提供客户价值的重要性系数;该方法不需要复杂的计算过程,利用三角模糊数处理语义的模糊性且依托软件系统自动检验一致性,提高了评价效率和准确度。针对生态位优势仅适用于完全竞争状态的优势计算,将生态位重叠与生态位优势结合,提出的竞争优势公式可以体现方案间竞争程度和生态位优势表示方案间的竞争优势的优点,反映方案间真实的竞争状态。最后以某新能源汽车制造企业PSS方案评价问题为例验证了所提方法的有效性。     

An integrated decision-making method for product design scheme evaluation based on cloud model and EEG data

Selecting the optimal design scheme is a vital task in the product design area. It not only improves the performance of the product, but also leads to the greatest satisfaction of customers. However, existing methods express qualitative evaluation information roughly, and none of them has taken the implicit psychological states of customers into consideration. Therefore, an integrated decision-making method for product design scheme evaluation is proposed. This method applies the cloud model to facilitate the evaluation process of experts and uses the EEG data to reveal the psychological states of customers. Benefit from the probability theory and fuzzy set theory, the cloud model deals with the fuzziness and randomness simultaneously. It can decrease the cognitive discrepancy of experts and allow the information distortion to be neutralized to a great extent. Since the experts are not the final users of products, the evaluation results from experts cannot truly reflect the psychological states of customers when they use the product. An experiment is designed to collect the EEG data which can reveal the implicit psychological states of customers. The recorded data are segmented based on the operation process and tagged with the self-reported psychological states. Subsequently, the wavelet packet decomposition is applied and the sample entropy of each EEG frequency band is extracted as the feature. Taking advantage of the random forest classifier, the psychological states of customers can be classified with the average accuracy of 90.76%. This study can lead to a practical system for automatic assessment of psychological states in future applications. The evaluation process of elevator design schemes is conducted as a case study to illustrate the feasibility of the proposed method.     

基于防火墙与入侵检测系统联动的校园网GSN全局部署

本文介绍了校园网的安全现状和校园网面临的主要威胁,分析了防火墙、入侵检测系统存在的不足,结合学院校园网实际情况给出GSN全局安全网络部署方案,并针对GSN全局安全网络第三阶段部署中存在的网络安全问题,提出基于开放端口的防火墙与入侵检测系统的联动模式,并给出具体实现方案。实践证明这种联动可以有效提升防火墙的机动性和实时反应能力,增强了入侵检测系统的阻断功能。     

Group interaction styles in a virtual context: The effects on group outcomes

The influence of communication and information technologies (TICs) on group functioning and group outcomes is an important topic. Interdependent group work implies the need to communicate in order to share information and knowledge related to the task. The importance of this group interaction in the group functioning and outcomes stands out. In this sense, a line of investigation has arisen to study the role of interaction styles in the relationship between communication technology and group outcomes, as some functional or dysfunctional outputs depend on group interaction styles. From this perspective, the objective of this study is twofold: (1) to analyze the group interaction styles in virtual teams over time, and (2) to analyze whether the group virtuality level moderates the relationships between group interaction style and group outcomes over time. Data was collected from a laboratory study in which 44 groups of four members participated. Groups were randomly assigned to communication contexts with different virtuality levels. The results obtained have shown a differential role of group interaction style according to the group virtuality level. Virtuality level plays a moderate role in the relationships between passive group interaction style and objective and subjective outcomes and between constructive interaction style and subjective outcomes.     

A modified wave equation with diffusion effects and its application as a smoothing scheme for seismic wave propagation simulations

We present a new modified wave equation and apply it to develop a smoothing scheme for seismic wave propagation simulations. With mathematical rigour we show that the solution of the new equation, which is derived as an analog of the advection–diffusion equation, can be obtained by the spatial convolution between a solution of the wave equation and the heat kernel and has a finite propagation speed and a diffusion effect. Using numerical experiments we show that the smoothing scheme based on the modified wave equation has the following advantages. Firstly, it preserves the characteristics of the wave equation such as wave propagation speed. Secondly, it selectively removes the short-wavelength components of the solution. Lastly, the energy decreases slowly after the short-wavelength components have been removed. Since our smoothing scheme can be implemented by adding simple correction terms to usual schemes, it can easily be applied to the seismic wave equation.     

The effects of source representation and goal instructions on college students' information evaluation behavior change

We investigated ways of scaffolding information evaluation behavior (IEB) in online inquiry contexts. Previous instructional support simplified IEB and rarely critically addressed the cognitive load that accompanies multiple representations or naïve task perception that hinders critical evaluation. We conducted a longitudinal, 2 × 2 quasi-experimental study in an introductory college biology course, varying (A) Source Representation Scaffolds to address limited cue awareness and cognitive load and (B) Goal Instructions to address task perception. For treatment A, students were given an annotation tool in addition to a checklist (Control A). For treatment B, instead of persuasion goal instructions (Control B), written task directions prompted student to consider alternative ideas (balanced reasoning goals). We measured students' IEB four times. We also measured individual task perception and cognitive capacity. Multilevel analyses identified the specific nature of changes in IEB. On average, IEB did not improve much in the baseline group while task perception and cognitive capacity differentiated IEB scores. Conversely, both annotation and balanced reasoning goals yielded improved gains in IEB, but there was a negative interaction effect when they were combined. The results demonstrate the benefits of annotation and balanced reasoning goals but suggest the need to address possible difficulties in using multiple scaffolds.     

基于结构熵权 TOPSIS 法的产品设计方案评估研究

为了提高企业在产品设计方案评估阶段进行合理决策的效率,提出了一种基于结 构熵权双基点法(TOPSIS)的产品设计方案评估方法。在评估流程中,首先确定产品设计方案评 价指标,专家对各评价指标进行重要度排序,在得到了“典型排序”后经过结构熵计算和“认识盲 度”计算,得出各评价指标的权重,以替代双基点法中专家主观设定的权重系数;其次,构建设 计方案各指标加权标准决策的矩阵,进而求得各指标的理想解,基于以上可得到各设计方案距 离理想解的相对贴近度,经对比后确定设计方案的排序情况,从而得到各方案的优劣。最后, 将该评估流程应用于录音笔设计方案评估的决策中,验证了该方法的可行性与有效性。     

项目制方式开展专业建设浅谈

本文对以项目制方式开展专业建设的组织形式、建设计划、建设标准、实施保障、评审验收等各方面的工作内容加以论述,并阐明了建设模式的有效性和关键点。     

Design evaluation of information appliances using augmented reality-based tangible interaction

In this paper, we propose an approach to tangible augmented reality (AR) based design evaluation of information appliances, which not only exploits the use of tangible objects without hardwired connections to provide better visual immersion and support more tangible interaction, but also facilitates the adoption of a simple and low cost AR environment setup to improve user experience and performance. To enhance the visual immersion, we develop a solution for resolving hand occlusion in which skin color information is exploited with the use of the tangible objects to detect the hand regions properly. To improve the tangible interaction with the sense of touch, we introduce the use of product- and fixture-type objects, which provides the feelings of holding the product in his or her hands and touching buttons with his or her index fingertip in the AR setup. To improve user experience and performance in view of hardware configuration, we devise to adopt a simple and cost-effective AR setup that properly meets guidelines such as viewing size and distance, working posture, viewpoint matching, and camera movement. From experimental results, we found that the AR setup is good to improve the user experience and performance in design evaluation of handheld information appliances. We also found that the tangible interaction combined with the hand occlusion solver in the AR setup is very useful to improve tangible interaction and immersive visualization of virtual products while making the user experience the shapes and functions of the products well and comfortably.