Cyberpandemics: History, Inevitability, Response

As cyberspace has evolved into a large, dynamic, and tangled web of computing devices, engineers often fail to design in dependability properties—such as stability, robustness, and security—at the system level. Consequently, unintentional and malevolent actions taken in cyberspace have affected critical infrastructures in the physical world. These disturbances and systems' resultant undependable behavior can progress and spread like infectious disease-like cyberpandemics.     

Currents: Trends, People, Projects

Along with the more public debate about the benefits the Semantic Web is - or isn't - delivering to the Internet, a related undercurrent of discussion is growing about software engineering's future. In the vanguard of this discussion, some researchers and software engineers are advocating that Semantic Web technologies should be key components of the next paradigm of software development. These advocates, however, are discovering that the ongoing debate about the Semantic Web's ultimate usefulness is being fought over the user experience - whether or not the principles behind the Semantic Web are just too complex to be truly useful to the bulk of Internet users.     

Splaysort: Fast,Versatile, Practical

Adaptivity in sorting algorithms is sometimes gained at the expense of practicality. We give experimental results showing that Splaysort — sorting by repeated insertion into a Splay tree — is a surprisingly efficient method for in-memory sorting. Splaysort appears to be adaptive with respect to all accepted measures of presortedness, and it outperforms Quicksort for sequences with modest amounts of existing order. Although Splaysort has a linear space overhead, there are many applications for which this is reasonable. In these situations Splaysort is an attractive alternative to traditional comparison-based sorting algorithms such as Heapsort, Mergesort, and Quicksort.     

Cyberattacks: Why, What, Who, and How

Enterprises rely extensively on computerized information systems and electronic data in cyberspace to perform their daily activities and business. Today, virtually all public and private organizations connect to and live in cyberspace. As computers, information systems, and networking have become more ubiquitous, cybersecurity has become more critical for the continuity of business operations. To better understand cybersecurity, this article discusses the four "W's" of cyberattacks. It starts with an overview of the cause of cybersecurity problems, analyzes the challenges associated with it, outlines the cyberattacker profile, discusses cyberattack patterns, and finally summarizes recent cyberattack trends.     

Domain-Specific Languages: What, Why, How

Domain-specific languages (DSLs) are being increasingly used as a realistic approach to address a program family. That is, a set of programs that shares enough commonalities to be considered as a whole. These programs may already exist or be expected to be developed. In this situation, in principle, software development can benefit from introducing a DSL in that (1) it offers concise and specific notations to express a member of the program family, and (2) it enables the development of safe code thanks to its restricted semantics and/or requirements for additional information.The Compose group has developed DSLs for various domains such as device drivers, active networking, and process scheduling, and built some experience in designing and implementing DSLs. In this talk we will report on the outcomes of this line of work. In particular, we will attempt to provide a practical definition of a DSL, and give the conditions to make this approach successful. We will discuss actual benefits of the DSL approach. Finally, we will outline a methodology to design and implement a DSL.     

Coolstreaming: Design, Theory, and Practice

Peer-to-peer (P2P) technology has found much success in applications like file distributions and VoIP yet, its adoption in live video streaming remains as an elusive goal. Our recent success in Coolstreaming system brings promises in this direction; however, it also reveals that there exist many practical engineering problems in real live streaming systems over the Internet. Our focus in this paper is on a nonoptimal real working system, in which we illustrate a set of existing practical problems and how they could be handled. We believe this is essential in providing the basic understanding of P2P streaming systems. This paper uses a set of real traces and attempts to develop some theoretical basis to demonstrate that a random peer partnership selection with a hybrid pull-push scheme has the potentially to scale. Specifically, first, we describe the fundamental system design tradeoffs and key changes in the design of a Coolstreaming system including substreaming, buffer management, scheduling and the adopt of a hybrid pull-push mechanism over the original pull-based content delivery approach; second, we examine the overlay topology and its convergence; third, using a combination of real traces and analysis, we quantitatively provide the insights on how the buffering technique resolves the problems associated with dynamics and heterogeneity; fourth, we show how substream and path diversity can help to alleviate the impact from congestion and churns; fifth, we discuss the system scalability and limitations.     

Explore, excogitate, exploit: component mining

The author describes a process of component mining. His source of candidate components, or his “mine”, is a set of highly respected components from an earlier generation: the famous Unix utilities. He shows how to identify the most promising of these candidates and re-encapsulate them in components that satisfy today's views of component based development, based on the principles of object technology     

Quasi-synchronous checkpointing: Models, characterization, andclassification

Checkpointing algorithms are classified as synchronous and asynchronous in the literature. In synchronous checkpointing, processes synchronize their checkpointing activities so that a globally consistent set of checkpoints is always maintained in the system. Synchronizing checkpointing activity involves message overhead and process execution may have to be suspended during the checkpointing coordination, resulting in performance degradation. In asynchronous checkpointing, processes take checkpoints without any coordination with others. Asynchronous checkpointing provides maximum autonomy for processes to take checkpoints; however, some of the checkpoints taken may not lie on any consistent global checkpoint, thus making the checkpointing efforts useless. Asynchronous checkpointing algorithms in the literature can reduce the number of useless checkpoints by making processes take communication induced checkpoints besides asynchronous checkpoints. We call such algorithms quasi-synchronous. In this paper, we present a theoretical framework for characterizing and classifying such algorithms. The theory not only helps to classify and characterize the quasi-synchronous checkpointing algorithms, but also helps to analyze the properties and limitations of the algorithms belonging to each class. It also provides guidelines for designing and evaluating such algorithms     

机器翻译研究现状与展望

本文回顾机器翻译研究的历史，介绍典型的机器翻译方法，包括：基于规划、基于统计以及基于实例的机器翻译方法；针对机器翻译的研究现状，详细介绍和分析了基于混合策略的机器翻译方法，对统计以及机器学习方法在机器翻译中的应用进行了描述；论文还介绍了当前机器翻译评测技术；最后对机器翻译进行总结和展望。     

Across disciplines: risk, design, method, process, and tools

In the search for solutions to make software development more predictable and controllable, one often looks for parallels in other disciplines such as architecture, bridge construction, and so on. The article looks at software development from the perspective of the electrical industry. Inspired by their management tradition, ATH techniek b.v. has learned to apply proven management techniques to software development. Simple and commonsense principles yield excellent results; for instance, developers reduced risk by estimating project effort using two different measures and by controlling execution. Comparing the software development processes with what goes on in the rest of the company or another application domain can be instructive