Current and future research directions in network optimization

In this paper, we discuss a number of current and future research directions in network optimization. First, we categorize current research efforts as primarily methodological or primarily applied and we carefully define the boundaries of each class. In addition, we survey the present capabilities of network algorithms. Next, we delineate objectives in each class. Finally, we list several network problems for each class that should, in our opinion, be investigated and we give pertinent background information.     

From designing objects to designing fields—from control to freedom

In this paper we want to explore Field as a concept and as a metaphor for understanding interactive systems. By interactive systems we mean both systems and artworks, where the user by interacting changes the course of events. We intend to show why we need new terms and why we consider Field to be a fruitful concept and term. Further we will show how the Field concept changes both our understanding of what we do as designers and composers and how we acknowledge our audience. We will exemplify the design consequences of the Field concept by going through some design considerations we made when designing the audio tactile installation Mufi.     

移动警务系统中VPN和RADIUS用户认证技术的应用

本文将通过讨论VPN技术和RADIUS用户认证技术的组成原理,采用VPN技术和RADIUS用户认证技术相结合的方法,解决当承载网络采用CDMA1X时的公共移动通信网的安全接入问题。     

Partial evaluation of Maple

Having been convinced of the potential benefits of partial evaluation, we wanted to apply these techniques to code written in Maple, our Computer Algebra System of choice. Maple is a very large language, with a number of non-standard features. When we tried to implement a partial evaluator for it, we ran into a number of difficulties for which we could find no solution in the literature. Undaunted, we persevered and ultimately implemented a working partial evaluator with which we were able to very successfully conduct our experiments, first on small codes, and now on actual routines taken from Maple’s own library. Here, we document the techniques we had to invent or adapt to achieve these results.     

多用户MIMO-OFDM的资源分配和性能分析

论文主要考虑多用户的MIMO-OFDM问题,以使得各个用户更公平有效地分配网络资源。文章首先给出MIMO-OFDM模型,然后引入反映用户满意程度的效益函数,并给出在MIMO-OFDM模型下的效益函数具体形式。其次,进行资源分配,重点考虑OFDM的各个子载波该分配给哪个用户,以及总功率该如何分配给各个子载波,从而实现系统的最优化。最后,文章给出了仿真结果,并着重对仿真结果进行了详细的性能分析。     

一个嵌入式实时Linux的技术研究

根据实验室项目的需求，简要介绍了将Linux嵌入化需要考虑的几个方面的问题，对Linux的实时性能作了详细的分析，提出了提高Linux的实时性的解决方案。     

Emotion recognition from physiological signals using wireless sensors for presence technologies

In this article we describe a new approach to enhance presence technologies. First, we discuss the strong relationship between cognitive processes and emotions and how human physiology is uniquely affected when experiencing each emotion. Secondly, we introduce our prototype multimodal affective user interface. In the remainder of the paper we describe the emotion elicitation experiment we designed and conducted and the algorithms we implemented to analyse the physiological signals associated with emotions. These algorithms can then be used to recognise the affective states of users from physiological data collected via non-invasive technologies. The affective intelligent user interfaces we plan to create will adapt to user affect dynamically in the current context, thus providing enhanced social presence.     

The Semantics of "Semantics"

Outside of computer science, semantics is the providence of philosophy, where we talk about what we mean when we talk, as well as ontology (what there is to know) and epistemology (how we know it). The nice thing about computer science is that, in contrast to philosophy, we can establish whether different representations make a computational difference. That's what makes what we do engineering/science. In this paper, the author distinguished the meaning of semantics (in programming) from ontologies and logics.     

Designing a document-centric coordination application over the Internet

In this paper we describe an experience in designing a groupware application distributed over the WWW to solve a conference management problem. The system we design coordinates the activities of several people engaged in reviewing and selecting papers submitted for a scientific conference. We discuss why such an application is interesting and describe how we designed it. The architecture we suggest implements what we call an active Web, because it includes entities which we are able to use and provide services offered through WWW infrastructures. Users, agents, and active documents can interoperate using a set of basic services for communication and synchronization. The active Web infrastructure we describe here is based on coordination technology integrated with Java.     

Self-surveillance privacy &; the Personal Data Guardian

We often see the government or the corporation as the greatest threat to information privacy. But due to a nascent data practice called “self-surveillance,” the greatest threat may actually come from ourselves. Using various existing and emerging technologies, such as GPS-enabled smartphones, we are beginning voluntarily to measure ourselves in granular detail - how long we sleep, where we go, what we breathe, what we eat, how we spend our time. And we are storing these data casually in the “cloud,” and giving third-parties broad access. This practice of self-surveillance will decrease information privacy in troubling ways. To counter this trend, we recommend the creation of the Personal Data Guardian, a new professional who manages Personal Data Vaults, which are repositories for self-surveillance data.     

Observation and identification tools for non-linear systems: application to a fluid catalytic cracker

In this paper we recall general methodologies we developed for observation and identification in non-linear systems theory, and we show how they can be applied to real practical problems.

In a previous paper, we introduced a filter which is intermediate between the extended Kalman filter in its standard version and its high-gain version, and we applied it to certain observation problems. But we were missing some important cases. Here, we show how to treat these cases.

We also apply the same technique in the context of our identifiability theory.

As non-academic illustrations, we treat a problem of observation and a problem of identification, for a fluid catalytic cracker (FCC). This FCC unit is one of the most crucial from an economic point of view for the petroleum industry.     

Programming pervasive spaces

With the invention of the PC and emergence of the network, we realized we need new concepts and capabilities to program networks of computers. Standards such as TCP/IP and IEEE 802 played a major role in transforming the first computer network concept (Arpanet) to the Internet we know today. However, we also had to invent new computing models such as the client-server model, transactions, distributed objects, Web services, disconnected operation, and computing grids. Furthermore, we had to invent various middleware to support these emerging models, hiding the underlying system's complexity and presenting a more programmable view to software and application developers. Today, with the advent of sensor networks and pinhead-size computers, we're moving much closer to realizing the vision of ubiquitous and pervasive computing. However, as we create pervasive spaces, we must think ahead to consider how we program them, just as we successfully programmed the mainframe and, later on, the Internet.     

Refinement for user interface designs

Formal approaches to software development require that we correctly describe (or specify) systems in order to prove properties about our proposed solution prior to building it. We must then follow a rigorous process to transform our specification into an implementation to ensure that the properties we have proved are retained. Different transformation, or refinement, methods exist for different formal methods, but they all seek to ensure that we can guide the transformation in a way which preserves the desired properties of the system. Refinement methods also allow us to subsequently compare two systems to see if a refinement relation exists between the two. When we design and build the user interfaces of our systems we are similarly keen to ensure that they have certain properties before we build them. For example, do they satisfy the requirements of the user? Are they designed with known good design principles and usability considerations in mind? Are they correct in terms of the overall system specification? However, when we come to implement our interface designs we do not have a defined process to follow which ensures that we maintain these properties as we transform the design into code. Instead, we rely on our judgement and belief that we are doing the right thing and subsequent user testing to ensure that our final solution remains useable and satisfactory. We suggest an alternative approach, which is to define a refinement process for user interfaces which will allow us to maintain the same rigorous standards we apply to the rest of the system when we implement our user interface designs.     

电梯规划的动态模型

讨论了写字楼上下班高峰期的电梯规划问题。首先提出了电梯方案的衡量标准,然后建立了一个比较完整的“动态规划”模型,对模型进行了求解。最后,对结果作了进一步的讨论,讨论了该模型对一般建筑以及超高建筑规划时候结果的不同,并回过头来验证了衡量标准的正确性。最后根据一个实际问题给出解决的方案。     

基于WEB 模式的存储统计监控系统

借助WEB数据库应用技术,也即LAMP(linux、apache、mysql、php)技术构建了具有安全认证功能的统一的存储信息管理平台,在此平台上,通过shell编程实现了用户数据按照时间节点的统计,通过php编程和apache实现了统计信息的发布、更新,通过mysql数据库技术实现了用户过往数据的管理。此外,通过SNMP协议和MIB获取存储设备状态,并通过php编程实现状态信息的发布、更新。     

Theoretical aspects of connectivity-based multi-hop positioning

We investigate the theoretical limits of positioning algorithms. In particular, we study scenarios where the nodes do not receive anchors directly (multi-hop) and where no physical distance or angle information whatsoever is available (connectivity-based). Since we envision large-scale sensor networks as an application, we are interested in fast, distributed algorithms. As such, we show that plain hop algorithms are not competitive. Instead, for one-dimensional unit disk graphs we present an optimal algorithm HS. For two or more dimensions, we propose an algorithm GHOST which improves upon the basic hop algorithm in theory and in simulations.     

基于OPNET的校园网络性能的仿真与优化

基于OPNET仿真平台,对校园网进行了建模,实现了对该校园网的相关性能指标的仿真,在给出了仿真结果的同时,对仿真结果进行了较为全面的分析,给出了一个较为恰当的校园网络优化策略,并根据这些策略,再次运用OP-NET仿真平台对该校园网的模型加以改进之后,得出仿真的对比结果加以验证。     

基于小波模糊聚类的均质纹理和非均质纹理图象检索

基于内容的图象检索是近年来的研究热点 ,为此提出了一种自动区分均质纹理和非均质纹理图象 ,并对这两类图象分别进行检索的算法 .算法首先从图象离散小波变换的低频子带提取一定的颜色和纹理特征用于模糊聚类 ,将图象的低频子带分割为一定的区域 ;然后根据分割的结果将图象自动语义分类为均质纹理或者非均质纹理图象 ;最后对均质纹理和非均质纹理图象分别提取不同的特征矢量 ,并按照一定的相似度准则检索图象 .实验结果表明 ,该算法具有良好的均质纹理和非均质纹理图象分类和检索性能 .     

Application design for wearable and context-aware computers

To effectively integrate wearable computers into ubiquitous computing environments, we must address several important challenges. How do we develop social and cognitive application models? How do we integrate input from multiple sensors and map them to users' social and cognitive states? How do we anticipate user needs? How do we interact with users? To address mobile-application design challenges, the authors created four user interface models that map problem-solving capabilities to application requirements.     

Using Meta-Model Transformation to Model Software Evolution

Understanding how software systems evolve is useful from different perspectives: reverse engineering, empirical studies etc.. For an effective understanding we need an explicit meta-model. We introduce Hismo, a meta-model which is centered around the notion of history and we show how we can obtain it from a snapshot meta-model. Based on our experience in developing the Hismo reverse engineering system, we show how we can transform a snapshot meta-model in a history meta-model.