Beeping a maximal independent set

We consider the problem of computing a maximal independent set (MIS) in an extremely harsh broadcast model that relies only on carrier sensing. The model consists of an anonymous broadcast network in which nodes have no knowledge about the topology of the network or even an upper bound on its size. Furthermore, it is assumed that an adversary chooses at which time slot each node wakes up. At each time slot a node can either beep, that is, emit a signal, or be silent. At a particular time slot, beeping nodes receive no feedback, while silent nodes can only differentiate between none of its neighbors beeping, or at least one of its neighbors beeping. We start by proving a lower bound that shows that in this model, it is not possible to locally converge to an MIS in sub-polynomial time. We then study four different relaxations of the model which allow us to circumvent the lower bound and find an MIS in polylogarithmic time. First, we show that if a polynomial upper bound on the network size is known, it is possible to find an MIS in $\mathcal O (\log ^3 n)$ time. Second, if we assume sleeping nodes are awoken by neighboring beeps, then we can also find an MIS in $\mathcal O (\log ^3 n)$ time. Third, if in addition to this wakeup assumption we allow sender-side collision detection, that is, beeping nodes can distinguish whether at least one neighboring node is beeping concurrently or not, we can find an MIS in $\mathcal O (\log ^2 n)$ time. Finally, if instead we endow nodes with synchronous clocks, it is also possible to find an MIS in $\mathcal O (\log ^2 n)$ time.     

Beyond Search: Content Applications

Content providers and publishers are finding more and more that they don't compete on content, but on what they can do with that content. "Content was king" back in 1997, according to Thomson Corp. Senior Vice President David Turner, in his 2006 National Federation of Abstracting and Information Services presentation ("The Thomson Transformation: Remaking a Global 500 Company," http://www. nfais.org/TurnerNFAIS06.ppt). Now content providers and publishers are moving "up the value pyramid" by competing on applications built on top of a technology platform that sits on top of content. We call these content applications. People often associate content with a search engine and applications with data (and therefore a relational database management system). But if you were designing a platform for content applications today from scratch, you would not use either a search engine or an RDBMS as the starting point. You would start with a representation of semistructured content-stored and indexed efficiently and securely in a content repository. You would also need a powerful, content-focused query/programming language. In addition, you would take the learnings from the world of search engines and the world of databases, add modern content technologies such as XML and XQuery, and come up with a brand new platform     

基于特征挖掘的基因组缺失变异集成检测方法

随着高通量测序技术的应用与发展,基于测序的缺失变异检测方法大量涌现。然而,单一检测方法仍存在适用的局限性以及检测精度与敏感度不足的问题。为此,提出一种基于多检测理论融合的特征挖掘与机器学习算法集成的基因组缺失变异综合检测方法。该方法将多种工具应用于个体缺失变异检测,得到变异检测初始集;再根据多种检测理论对初始集中的缺失变异进行序列特征挖掘与特征提取;最后,将检测工具与机器学习算法相融合以获得集成的检测方法,剔除初始集中的假阳性变异,获得最终的结果集。基于千人基因组计划数据的实验表明,相较于单个工具的检测结果,该方法在检测精度和敏感度上均占优势;相较于多个工具检测结果的直接组合,该方法在损失少许检测敏感度的前提下显著地提高了检测精度。     

医院无线呼救系统

基于无线传输方式,本文提出一种无线呼救系统,旨在解决一些不方便搭建有线呼叫系统的医院急救问题。该系统由病床模块、护士模块和护士站模块组成。三部分之间的数据传输均采用无线通信的方式。由于比一般的系统增设了护士模块部分,因此可以将病人的呼叫信息及时传递给护士,以避免因巡房等因素造成的"时间空白"。本文中着重对该系统的呼叫功能及其软件设计进行了介绍。     

基于电话网络的智能控制器设计与实现

探讨了一种适合于电话网络的智能控制器设计,该控制器采用上下位机通信工作方式,具有信号检测、振铃检测、模拟摘机、信号音检测、DTMF信号收发等功能,下位机检测信号后.摘机拨打上位机电话,并利用DTMF编码将信号和地址信息发送到上住机,上位机也可摘机拔打下位机电话,并对下位机进行各种远程控制、设置等功能.     

Context Awareness and Mobile Phones

This paper investigates some aspects of how context-awareness can support users of mobile phones, in particular the calling party. The use of mobile and stationary phones is discussed in relation to situational properties of a phone conversation, especially with regards to who might benefit from context-awareness in this context. An initial hypothesis is that mobile phone users communicate context information to each other (verbally) to a much higher degree than do stationary phone users. Mobile phone users could benefit much from context awareness technology, in particular when about to make a call, if they can receive context information regarding the person they are trying to reach prior to establishing the call. We argue that such technology should require low amounts of explicit user interaction, and could lead to less disrupting calls in inappropriate moments, as well as less frustration for the calling party when a call is not answered.     

在．NET框架的类对象中实现COM对象的引用

COM技术是原来微软为了解决组件调用而推出的一种解决方法．但在微软新的开发战略．NEI、平台下．没有沿用原来的COM技术．而是采用了一种新的技术：程序集方法。为了在,NET的开发环境下调用原来用COM技术实现组件的方法，文中介绍了,NET中的运行库可调用包装(RCW)技术，说明了如何用这一技术来解决这一问题,用Delphi6新建了一个COM组件，演示了在NFT的平台下利用RCW技术如何调用COM组件,说明了此方法的运用。例子证明利用RCW技术就能很好地在,NET框架的类对象中实现对COM对象的引用。     

Fast and precise points-to analysis

Many software engineering applications require points-to analysis. These client applications range from optimizing compilers to integrated program development environments (IDEs) and from testing environments to reverse-engineering tools. Moreover, software engineering applications used in an edit-compile cycle need points-to analysis to be fast and precise.In this article, we present a new context- and flow-sensitive approach to points-to analysis where calling contexts are distinguished by the points-to sets analyzed for their call target expressions. Compared to other well-known context-sensitive techniques it is faster in practice, on average, twice as fast as the call string approach and by an order of magnitude faster than the object-sensitive technique. In fact, it shows to be only marginally slower than a context-insensitive baseline analysis. At the same time, it provides higher precision than the call string technique and is similar in precision to the object-sensitive technique. We confirm these statements with experiments using a number of abstract precision metrics and a concrete client application: escape analysis.     

基于图像的关系型数据库水印算法

在关系型数据库中嵌入代表所有权的水印信息,实现其版权保护,是数据库安全领域新的研究热点。该文利用数值型数据最低有效位的变换,提出了一种新的基于图像的数据库水印算法。该算法使用标记算法和向量迭代算法,实现了水印图像在关系型数据库数据中的嵌入。根据水印的分量统计独立性,采用FastICA算法提取出水印图像和原始数据。实验结果表明,在盲测环境中该水印具有很好的抗攻击能力。     

基于CAR构件的“Elastos”手机邮件系统设计和实现

如今的智能手机除了具备基本的通话、收发短信息的功能外,还应具有上网收发电子邮件、彩信,录音录像等功能。随着信息时代的到来,Email这一通信方式已经被大家广泛接受,为人们的生活和工作提供了很多便利。Email已经成为智能手机的重要组成部分。同时基于CAR构件的智能手机应用开发模型具有结构清晰、模块耦合度低、复用性高且模块可升级等特点,该模型已运用于“和欣”智能手机实际应用开发中。介绍了Elastos平台下智能手机应用的架构,并在此架构基础上设计和实现电子邮件系统。     

JP2: Call-site aware calling context profiling for the Java Virtual Machine

Calling context profiling fulfills programmers’ information needs to obtain a complete picture of a program’s inter- and intra-procedural control flow, which are important for workload characterization, debugging, profiling, program comprehension, and reverse engineering. Many existing calling context profilers for Java, however, resort to sampling or other incomplete instrumentation techniques; thus, they collect incomplete profiles only. In this article we present JP2, a new calling context profiler for the Java Virtual Machine, which collects profiles that are not only complete but also call-site aware; that is, JP2 is able to distinguish between multiple call sites within a single method. JP2 supports selective profiling of the dynamic extent of chosen methods and supports profiling of native method invocations. Moreover, produced profiles contain execution statistics at the level of individual basic blocks of code, thereby preserving the intra-procedural control flow of the profiled applications. We rigorously evaluate the overhead incurred by JP2. This overhead is acceptable in tasks such as workload characterization. JP2 is freely available under an Open Source license.     

Understanding culinary innovation as relational: Insights from Tarde's relational sociology

This article argues that a relational view of innovation opens up new perspectives of examining and explaining how novelty develops in creative industries. Although many researchers have given time to this topic, a theoretically grounded concept of relational innovation remains undeveloped within the literature. To address this issue, I set out to offer a framework informed by Gabriel Tarde's relational sociology, by re‐interpreting this sociology with regard to practice theory. By applying this framework in an empirical study of haute cuisine, I identify three processes of innovating at varying degrees of novelty (repeating, adapting, and differentiating). By relating those processes in the form of practices‐nets, I show that innovating is not a linear development process, but that a culinary innovation emerges in between relations of everyday practices that define and transform its value. I hope, in this way, to contribute to a more complex and subtle understanding of culinary innovation as relational.     

Putting speech recognition to work in the telephone network

The use of speaker-independent speech recognition in the development of Northern Telecom's automated alternate billing service (AABS) for collect calls, third-number-billed calls, and calling-card-billed calls is discussed. The AABS system automates a collect call by recording the calling party's name, placing a call to the called party, playing back the calling party's name to the called party, informing the called party that he or she has a collect call from that person, and asking. `Will you pay for the call?' The operation of AABS, the architecture of the voice interface, and the speech recognition algorithm are described, and the accuracy of the recognizer is discussed. AABS relies on isolated-word recognition, although more advanced techniques that can recognize continuous speech are being pursued     

基于硬件加密卡技术的RSA加密引擎的局部封装

目前主流的VPN是通过SSL协商进行认证的,其在调用Openssl的加密引擎过程中带来一个问题,即进行数据加密所使用的公钥不是自身的密钥,于是加密引擎不仅要有对私钥解密进行硬件实现,还要有对公钥加密实现原有算法调用的技术。本文介绍了目前主流的Openssl实现硬件RSA加密引擎仅对私钥解密数据进行调用,而对于公钥加密数据不调用的局部封装方法,有着重要的实用价值。     

嵌入式SQL的应用

数据库应用系统开发中,用高级语言来写数据库应用程序时,可以用ODBC/CLI,也可以用嵌入式SQL.如果是用ODBC/CLI,则你的高级语言程序中调用ODBC/CLI的各种API函数.属于底层开发,用嵌入式SQL方式写程序执行效率更高。用嵌入式SQL的概念和实现的方法,用DBMS预编译器和开发工具,对两种开发和调用SQL的方式进行了详细地分析和比较,实现了用嵌入式SQL这种调用方法可以提高对数据库的性能和效率。     

基于MT8888的电话监测方法

根据电话监测与监管的要求,通过反复的实验和分析,设计了基于MT8888的电话监测系统,系统利用MT8888实现监听并线电话的主叫号码,并进行主叫状态的检测,另外,上位机还可以发送控制指令拔打指定号码。该监测系统改进了DTMF输出信号耦合电路,通过高效的软件控制,并结合摘挂机检测与模拟摘挂机电路,使系统在拨号之后能快速有效地进行回铃、忙音等主叫状态的检测。     

PowerBuilder中调用Windows API函数

简单描述了在PowerBuilder中调用Windows API函数的重要性。重点分析了PowerBuilder如何调用API函数,以及在调用过程中需要注意的事项。     

Supporting quantified queries in distributed databases

We show that some relational queries, which we call quantified queries are not well supported in distributed environments. We give a formal definition of quantified queries, propose a language in which to express said queries and provide a procedure to compute answers in this new language in the context of distributed databases. The proposed language is made up of high-level, declarative operators (called generalised quantifiers), and therefore it can be used in combination with several distributed frameworks. Our approach is designed to be as general as possible; it assumes horizontally partitioned relations, but nothing else, so no data placement or replication is used. We present an implementation and algorithms for the new language, propose some basic optimisations and give experimental results which show that the new approach is indeed quite efficient and scales well.     

一种基于目录和关系的混合数据模型

目录和关系数据库分别在架构、安全、事务处理等方面各有优点,而许多信息管理系统,特别是互联网应用(电子商务、分布应用)系统中,既需要目录数据结构的与组织资源架构的一致性和分布特征,也需要关系数据对事务处理、数据挖掘的优势,两种数据结构的结合可以使系统数据更加结构化、应用开发更加高效、变更更加灵活.本文提出了一个基于LDAP/X500目录和SOL数据操作语言的关系数据库的混合数据模型框架,来解决一些具有组织结构、资源管理,又有事务处理、数据分析应用系统的数据框架问题.     

Fast,accurate call graph profiling

Existing methods for call graph profiling, such as that used by gprof, deal badly with programs that have shared subroutines, mutual recursion, higher‐order functions, or dynamic method binding. This article discusses a way of improving the accuracy of a call graph profile by collecting more information during execution, without significantly increasing the overhead of profiling. The method is based on keeping track of a context, consisting of the set of subroutines that are active at a particular moment during execution, together with the calling arcs between these subroutines. The profiler records the time spent in each context during execution of the program, and thus obtains an accurate measurement of the total time during which each subroutine was active. By recording arc information for only the most recent activation of each subroutine, it is possible to arrange that even recursive programs give rise to a finite number of these contexts, and in typical real programs, the number of distinct contexts remains manageably small. The data can be collected efficiently during execution by constructing a finite‐state machine whose states correspond to contexts, so that when a context is entered for a second or subsequent time, only a single access of a hash table is needed to update the state of the profiling monitor. Copyright © 2003 John Wiley & Sons, Ltd.