bluuebunny/crossref_metadata_2025 huggingface dataset:
Market-based recommendation
Authors: Bohte Sander M. , Gerding Enrico , Poutré Han La
Published: January 2005

The amount of attention space available for recommending suppliers to consumers on e-commerce sites is typically limited. We present a competitive distributed recommendation mechanism based on adaptive software agents for efficiently allocating the "consumer attention space," or banners. In the example of an electronic shopping mall, the task is delegated to the individual shops, each of which evaluates the information that is available about the consumer and his or her interests (e.g. keywords, product queries, and available parts of a profile). Shops make a monetary bid in an auction where a limited amount of "consumer attention space" for the arriving consumer is sold. Each shop is represented by a software agent that bids for each consumer. This allows shops to rapidly adapt their bidding strategy to focus on consumers interested in their offerings.

For various basic and simple models for on-line consumers, shops, and profiles, we demonstrate the feasibility of our system by evolutionary simulations as in the field of agent-based computational economics (ACE). We also develop adaptive software agents that learn bidding-strategies, based on neural networks and strategy exploration heuristics. Furthermore, we address the commercial and technological advantages of this distributed market-based approach. The mechanism we describe is not limited to the example of the electronic shopping mall, but can easily be extended to other domains.
Object-based and image-based object representations
Authors: Samet Hanan
Published: January 2005

An overview is presented of object-based and image-based representations of objects by their interiors. The representations are distinguished by the manner in which they can be used to answer two fundamental queries in database applications: (1) Feature query: given an object, determine its constituent cells (i.e., their locations in space). (2) Location query: given a cell (i.e., a location in space), determine the identity of the object (or objects) of which it is a member as well as the remaining constituent cells of the object (or objects). Regardless of the representation that is used, the generation of responses to the feature and location queries is facilitated by building an index (i.e., the result of a sort) either on the objects or on their locations in space, and implementing it using an access structure that correlates the objects with the locations. Assuming the presence of an access structure, implicit (i.e., image-based) representations are described that are good for finding the objects associated with a particular location or cell (i.e., the location query), while requiring that all cells be examined when determining the locations associated with a particular object (i.e., the feature query). In contrast, explicit (i.e., object-based) representations are good for the feature query, while requiring that all objects be examined when trying to respond to the location query. The goal is to be able to answer both types of queries with one representation and without possibly having to examine every cell. Representations are presented that achieve this goal by imposing containment hierarchies on either space (i.e., the cells in the space in which the objects are found), or objects. In the former case, space is aggregated into successively larger-sized chunks (i.e., blocks), while in the latter, objects are aggregated into successively larger groups (in terms of the number of objects that they contain). The former is applicable to image-based interior-based representations of which the space pyramid is an example. The latter is applicable to object-based interior-based representations of which the R-tree is an example. The actual mechanics of many of these representations are demonstrated in the VASCO JAVA applets found at http://www.cs.umd.edu/˜hjs/quadtree/index.html.
Methodological frameworks for large-scale network analysis and design
Authors: Papachristodoulou Antonis , Li Lun , Doyle John C.
Published: January 2005

This paper emphasizes the need for methodological frameworks for analysis and design of large scale networks which are independent of specific design innovations and their advocacy, with the aim of making networking a more systematic engineering discipline. Networking problems have largely confounded existing theory, and innovation based on intuition has dominated design. This paper will illustrate potential pitfalls of this practice. The general aim is to illustrate universal aspects of theoretical and methodological research that can be applied to network design and verification. The issues focused on will include the choice of models, including the relationship between flow and packet level descriptions, the need to account for uncertainty generated by modelling abstractions, and the challenges of dealing with network scale. The rigorous comparison of proposed schemes will be illustrated using various abstractions. While standard tools from robust control theory have been applied in this area, we will also illustrate how network-specific challenges can drive the development of new mathematics that expand their range of applicability, and how many enormous challenges remain.
On the scaling of congestion in the internet graph
Authors: Akella Aditya , Chawla Shuchi , Kannan Arvind , Seshan Srinivasan
Published: January 2005

As the Internet grows in size, it becomes crucial to understand how the speeds of links in the network must improve in order to sustain the pressure of new end-nodes being added each day. Although the speeds of links in the core and at the edges improve roughly according to Moore's law, this improvement alone might not be enough. Indeed, the structure of the Internet graph and routing in the network might necessitate much faster improvements in the speeds of key links in the network.

In this paper, using a combination of analysis and extensive simulations, we show that the worst congestion in the Internet AS-level graph in fact scales poorly with the network size (n1+ω(1), where n is the number of nodes), when shortest-path routing is used to route traffic between ASes. We also show, somewhat surprisingly, that policy-based routing does not exacerbate the maximum congestion when compared to shortest-path routing.

Our results show that it is crucial to identify ways to alleviate this congestion to avoid some links from being perpetually congested. To this end, we show that the congestion scaling properties of Internet-like graphs can be improved dramatically by introducing moderate amounts of redundancy in the graph in terms of parallel edges between pairs of adjacent nodes.
Capacity bounds for ad hoc and hybrid wireless networks
Authors: Agarwal Ashish , Kumar P. R.
Published: January 2005

We study the capacity of static wireless networks, both ad hoc and hybrid, under the Protocol and Physical Models of communication, proposed in [1]. For ad hoc networks with n nodes, we show that under the Physical Model, where signal power is assumed to attenuate as 1/rα, α > 2, the transport capacity scales as Θ(√n) bit-meters/sec. The same bound holds even when the nodes are allowed to approach arbitrarily close to each other and even under a more generalized notion of the Physical Model wherein the data rate is Shannon's logarithmic function of the SINR at the receiver. This result is sharp since it closes the gap that existed between the previous best known upper bound of O(nα-1/α) and lower bound of Ω(√n).

We also show that any spatio-temporal scheduling of transmissions and their ranges that is feasible under the Protocol Model can also be realized under the Physical Model by an appropriate choice of power levels for appropriate thresholds. This allows the generalization of various lower bound constructions from the Protocol Model to the Physical Model. In particular, this provides a better lower bound on the best case transport capacity than in [1].

For hybrid networks, we consider an overlay of μn randomly placed wired base stations. It has previously been shown in [6] that if all nodes adopt a common power level, then each node can be provided a throughput of at most Θ(1/log n) to randomly chosen destinations. Here we show that by allowing nodes to perform power control and properly choosing ν(1/log n), it is further possible to provide a throughput of Θ(1) to any fraction f, 0 < f < 1, of nodes. This result holds under both the Protocol and Physical models of communication. On the one hand, it shows that that the aggregate throughput capacity, measured as the sum of individual throughputs, can scale linearly in the number of nodes. On the other hand, the result underscores the importance of choosing minimum power levels for communication and suggests that simply communicating with the closest node or base station could yield good capacity even for multihop hybrid wireless networks.
Achieving speed and flexibility by separating management from protection
Authors: Leschke Tim
Published: January 2005

The modern operating system is currently caught in a tug-of-war between two forces. At one end, there is a force that is demanding that the operating system become more flexible to handle the needs of evolving hardware and evolving user applications. At the other end, there is a force that is demanding that the operating system become more efficient to meet the needs of faster hardware. If the modern operating system does not keep pace with these two forces, it could cause the progress in computer design to become stagnant.

One possible solution to this problem is the Exokernel Operating System - an extensible (or easily modifiable) operating system developed at the Massachusetts Institute of Technology. Extensibility allows the operating system to be flexible to change and also open to optimization.

Extensibility within an operating system has resulted in several new issues. For example, extensibility seems to make customer-support harder to provide. Furthermore, some multithreaded applications perform worse in an extensible environment. Lastly, some have argued that it is optimization, not extensibility, that should be credited for the enhanced operating system speeds.

In this paper, we discuss the Exokernel Operating System with some detail. We explore some of the issues that have kept the Exokernel design from being the main-stream approach. We propose solutions to these issues and we conclude by trying to motivate the reader to embrace the Exokernel approach.
A common framework for inter-process communication on a cluster
Authors: Geva Mordechai , Wiseman Yair
Published: January 2005

Many implementations of distributed shared memories (DSMs) have been developed to date. All of the implementations have taken into consideration, the performance issues of DSM systems more than other issues like the portability of programs and API. DSM systems have APIs that fit a specific system and require a programmer's adaptation to that specific API. A migration between systems might require a significant revision of a program. Moreover, programmers who write programs for SMPs need to rewrite large portions of their programs in order to scale up their programs from SMP to a cluster of computers. We are presenting a concept for a distributed system, in which an API for any IPC mechanism will be identical, or very close to the SMP's conventional API. This concept can accustom programmers to a distributed system with ease, as well as improving the migration of existing SMP programs to distributed systems.
Cryptanalysis of an efficient secure group signature scheme
Authors: Li Li-Hua , Liu Chi-Yu , Hwang Min-Shiang
Published: January 2005

Group signature has been proposed for many years, those schemes are still not efficient. In 2002, Shi proposed a group signature scheme based on the discrete logarithm problem. In Shi's scheme, he claims that his scheme is efficient compared to previous proposed schemes. Although his scheme is better than others, the scheme is not secure. In this article, we will show that Shi's scheme will be subjected forgery attack.
A simple password authentication using a polynomial
Authors: Liaw Horng-Twu , Fan Shiou-Wei , Wu Wei-Chen
Published: January 2005

Traditional remote password authentication schemes allow a user to submit his identity and its corresponding password. Then, through a specific algorithm, the server authenticates its users alone. Because these schemes are independent and each scheme develops a specific algorithm by itself, the development cost and computing cost are very high. To avoid the rise in costs, we present a simple password authentication scheme for multi-server environments. The scheme can generate a public polynomial that contains a specific Access Right (AR). The AR means the legal users have different level of authorization based on which server in the multi-server environment in used. Furthermore, the scheme can verify the authorization without a password table. The scheme can authorize many servers at one time so that the users who have registered with various servers do not need to remember different login passwords for each. The scheme also allows users to choose their passwords freely and update it off-line.
A secure one-time password authentication scheme using smart cards without limiting login times
Authors: Chang Ya-Fen , Chang Chin-Chen , Kuo Jui-Yi
Published: January 2005

With the one-time password concept, the S/Key scheme is widely utilized by the protocols with limited login times to defend against replay attack. By employing the simple and unidirectional hash function, the improved version of the S/Key scheme is proposed to withstand spoofing attack, pre-play attack and off-line dictionary attack. However, the schemes limit login times. Hence, we propose a scheme, preserving the same properties and withstanding the stolen-verifier attack, without limiting the login times.
Charles
Authors: Heaney Matthew J.
Published: January 2005

Charles is a container and algorithms library for Ada95, modeled closely on the C++ STL. The library provides both sequence and associative containers, and specifies the time and space semantics of each container. Charles is flexible and efficient, and its design has been guided by the philosophy that a library should stay out of the programmer's way.
The PragmAda reusable components
Authors: Carter Jeffrey R.
Published: January 2005

The PragmAda Reusable Components (PragmARCs) are a library of reusable components in a number of categories, and ranging from very basic to some quite high-level concepts. The PragmARCs have existed for over a decade, first in Ada 83 and now in Ada 95, and have been used on a variety of projects. A new version will probably appear once Ada 0X is standardized and widely available.
Reusable software components
Authors: Levine Trudy
Published: January 2005

There has been a continued interest in software reuse in the software engineering community, as evidenced by web services and Microsoft .NET, and by the continued work in product-line engineering. New users to software reuse should be made aware of the work that has been done by the Ada community and of the particular appropriateness of Ada for reuse. We therefore review in this column the issues involved in reuse with the Ada programming language. For those who are interested in investigating these topics in depth, we enclose a brief list of helpful sources. We will post this column on our web site, and gladly append any additional references that our readers may supply.
The pattern calculus
Authors: Jay C. Barry
Published: January 2005

There is a significant class of operations such as mapping that are common to all data structures. The goal of generic programming is to support these operations on arbitrary data types without having to recode for each new type. The pattern calculus and combinatory type system reach this goal by representing each data structure as a combination of names and a finite set of constructors. These can be used to define generic functions by pattern-matching programs in which each pattern has a different type. Evaluation is type-free. Polymorphism is captured by quantifying over type variables that represent unknown structures. A practical type inference algorithm is provided.
A tail-recursive machine with stack inspection
Authors: Clements John , Felleisen Matthias
Published: January 2005

Security folklore holds that a security mechanism based on stack inspection is incompatible with a global tail call optimization policy; that an implementation of such a language must allocate memory for a source-code tail call, and a program that uses only tail calls (and no other memory-allocating construct) may nevertheless exhaust the available memory. In this article, we prove this widely held belief wrong. We exhibit an abstract machine for a language with security stack inspection whose space consumption function is equivalent to that of the canonical tail call optimizing abstract machine. Our machine is surprisingly simple and suggests that tail calls are as easy to implement in a security setting as they are in a conventional one.
Lexical triggers and latent semantic analysis for cross-lingual language model adaptation
Authors: Kim Woosung , Khudanpur Sanjeev
Published: January 2005

In-domain texts for estimating statistical language models are not easily found for most languages of the world. We present two techniques to take advantage of in-domain text resources in other languages. First, we extend the notion of lexical triggers, which have been used monolingually for language model adaptation, to the cross-lingual problem, permitting the construction of sharper language models for a target-language document by drawing statistics from related documents in a resource-rich language. Next, we show that cross-lingual latent semantic analysis is similarly capable of extracting useful statistics for language modeling. Neither technique requires explicit translation capabilities between the two languages! We demonstrate significant reductions in both perplexity and word error rate on a Mandarin speech recognition task by using these techniques.
A hybrid language model based on a combination of
N
-grams and stochastic context-free grammars
Authors: Linares Diego , Benedí José-Miguel , Sánchez Joan-Andreu
Published: January 2005

In this paper, a hybrid language model is defined as a combination of a word-based n-gram, which is used to capture the local relations between words, and a category-based stochastic context-free grammar (SCFG) with a word distribution into categories, which is defined to represent the long-term relations between these categories. The problem of unsupervised learning of a SCFG in General Format and in Chomsky Normal Form by means of estimation algorithms is studied. Moreover, a bracketed version of the classical estimation algorithm based on the Earley algorithm is proposed. This paper also explores the use of SCFGs obtained from a treebank corpus as initial models for the estimation algorithms. Experiments on the UPenn Treebank corpus are reported. These experiments have been carried out in terms of the test set perplexity and the word error rate in a speech recognition experiment.
A maximum-entropy chinese parser augmented by transformation-based learning
Authors: Fung Pascale , Ngai Grace , Yang Yongsheng , Chen Benfeng
Published: January 2005

Parsing, the task of identifying syntactic components, e.g., noun and verb phrases, in a sentence, is one of the fundamental tasks in natural language processing. Many natural language applications such as spoken-language understanding, machine translation, and information extraction, would benefit from, or even require, high accuracy parsing as a preprocessing step.

Even though most state-of-the-art statistical parsers were initially constructed for parsing in English, most of them are not language-specific, in that they do not rely on properties of the language that are specific to English. Therefore, construction of a parser in a given language becomes a matter of retraining the statistical parameters with a Treebank in the corresponding language.

The development of the Chinese treebank [Xia et al. 2000] spurred the construction of parsers for Chinese. However, Chinese as a language poses some unique problems for the development of a statistical parser, the most apparent being word segmentation. Since words in written Chinese are not delimited in the same way as in Western languages, the first problem that needs to be solved before an existing statistical method can be applied to Chinese is to identify the word boundaries. This is a step that is neglected by most pre-existing Chinese parsers, which assume that the input data has already been pre-segmented.

This article describes a character-based statistical parser, which gives the best performance to-date on the Chinese treebank data. We augment an existing maximum entropy parser with transformation-based learning, creating a parser that can operate at the character level. We present experiments that show that our parser achieves results that are close to those achievable under perfect word segmentation conditions.
Using choiceboards to create business value
Authors: Bharati Pratyush , Chaudhury Abhijit
Published: January 2005

Choiceboards empower users while saving companies money---but the technology needs to be carefully tailored to provide the best customer experience.
Cyberaccess
Authors: Loiacono Eleanor T.
Published: January 2005

Many corporate Web sites contain barriers to accessibility. Fortunately, removing these obstacles will prove both relatively simple and beneficial.
Building systems that users want to use
Authors: Malhotra Yogesh , Galletta Dennis F.
Published: January 2005

User commitment is essential to the success of even the best-designed IT systems. And to make that connection successfully begins by examining the burning question: "Does IT matter?"
The many colors of multimedia security
Authors: Mercuri Rebecca T.
Published: January 2005

Protection of artistic content from illegal distribution involves significant gray areas in terms of methods and laws.
Semantic blogging and decentralized knowledge management
Authors: Cayzer Steve
Published: January 2005

Tapping into the structured metadata in snippets of information gives communities of interest effective access to their collective knowledge.
Information systems outsourcing
Authors: Dibbern Jens , Goles Tim , Hirschheim Rudy , Jayatilaka Bandula
Published: January 2005

In the last fifteen years, academic research on information systems (IS) outsourcing has evolved rapidly. Indeed the field of outsourcing research has grown so fast that there has been scant opportunity for the research community to take a collective breath, and complete a global assessment of research activities to date. This paper seeks to address this need by exploring and synthesizing the academic literature on IS outsourcing. It offers a roadmap of the IS outsourcing literature, highlighting what has been done so far, how the work fits together under a common umbrella, and what the future directions might be.

In order to adequately address the immense diversity of research on IS outsourcing and outsourcing in general, we develop a conceptual framework that helps us to categorize the literature. In particular, we look at the research objectives, methods used and theoretical foundations of the papers. In identifying the major research objectives, we view outsourcing as an organizational decision process and adapt Simon's stage model of decision making. This allows us to identify five major sourcing issues, from which at least one is covered by each academic article. These are the questions of why to outsource, what to outsource, which decision process to take, how to implement the sourcing decision, and what is the outcome of the sourcing decision. In analyzing the literature, we identify and structure the main explanatory factors and theoretical relationships within each of these sourcing stages. Based on our discussion of the research objectives, theoretical foundations and research approaches taken in the literature, we show how the various research streams hang together and we come up with a number of implications for research. Moreover, we identify a number of emerging sourcing issues. We believe that research on these "new" phenomena such as offshore outsourcing, application service providing and business process outsourcing would benefit from 'standing on the shoulders' of what has already been accomplished in the field of IS outsourcing.
"Who's in charge here?" communicating across unequal computer platforms
Authors: Velez Maria , Tremaine Marilyn Mantei , Sarcevic Aleksandra , Dorohonceanu Bogdan , Krebs Allan , Marsic Ivan
Published: January 2005

People use personal data assistants in the field to collect data and to communicate with others both in the field and office. The individual in the office invariably has a laptop or a high-end personal workstation and thus, significantly more computing power, more screen real estate, and higher volume input devices, such as a mouse and keyboard. These differences give the high-end user the ability to represent and manipulate collaborative tasks more effectively. It is therefore useful to know what impact these differences have on work performance and work communications. Four different platform combinations involving a PC and a PDA were used to examine the effect of communicating via heterogeneous computer platforms. The PC platform used a mouse, a keyboard, and a 3-dimensional screen display. The PDA platform used a stylus, soft buttons, and a 2-dimensional screen display. A variation of the Tetris wall-building game called Slow Tetris was used as the subjects' collaborative task. A second factor in the experiment was role asymmetry. One subject was arbitrarily put in charge of the task solution in all of the combinations. An analysis of the solution times found that subjects with mixed platforms worked slower than their homogeneous counterparts, that is, a person in charge with a PC worked faster if his partner had a PC. An in-depth analysis of the communication patterns found significant differences in the exchanges between heterogeneous and homogenous combinations. The PC-to-PDA combination (with the person on the PC in charge of the solution) took significantly more time than the PC-to-PC combination. This extra time appears to come from the disadvantage of having a partner on the PDA who is unable to help in solving the problems. The PDA-to-PC combination took approximately the same amount of time as the PDA-to-PDA combination despite having one team member with a better representation. This member was, unfortunately, not in charge of the solution. The PDA-to-PC heterogeneous combination exhibited more direction giving, less one-sided collaboration, and more takeover attempts than any of the other combinations. Overall, roles were maintained in the partnerships except for the person with the PDA directing the person with the PC.
ContactMap
Authors: Whittaker Steve , Jones Quentin , Nardi Bonnie , Creech Mike , Terveen Loren , Isaacs Ellen , Hainsworth John
Published: January 2005

Modern work is a highly social process, offering many cues for people to organize communication and access information. Shared physical workplaces provide natural support for tasks such as (a) social reminding about communication commitments and keeping track of collaborators and friends, and (b) social data mining of local expertise for advice and information. However, many people now collaborate remotely using tools such as email and voicemail. Our field studies show that these tools do not provide the social cues needed for group work processes. In part, this is because the tools are organized around messages, rather than people. In response to this problem, we created ContactMap, a system that makes people the primary unit of interaction. ContactMap provides a structured social desktop representation of users' important contacts that directly supports social reminding and social data mining. We conducted an empirical evaluation of ContactMap, comparing it with traditional email systems, on tasks suggested by our fieldwork. Users performed better with ContactMap and preferred ContactMap for the majority of these tasks. We discuss future enhancements of our system and the implications of these results for future communication interfaces and for theories of mediated communication.
Firmato
Authors: Bartal Yair , Mayer Alain , Nissim Kobbi , Wool Avishai
Published: January 2005

In recent years packet-filtering firewalls have seen some impressive technological advances (e.g., stateful inspection, transparency, performance, etc.) and wide-spread deployment. In contrast, firewall and security management technology is lacking. In this paper we present Firmato, a firewall management toolkit, with the following distinguishing properties and components: (1) an entity-relationship model containing, in a unified form, global knowledge of the security policy and of the network topology; (2) a model definition language, which we use as an interface to define an instance of the entity-relationship model; (3) a model compiler, translating the global knowledge of the model into firewall-specific configuration files; and (4) a graphical firewall rule illustrator.

We implemented a prototype of our toolkit to work with several commercially available firewall products. This prototype was used to control an operational firewall for several months. We believe that our approach is an important step toward streamlining the process of configuring and managing firewalls, especially in complex, multi-firewall installations.
System support for pervasive applications
Authors: Grimm Robert , Davis Janet , Lemar Eric , Macbeth Adam , Swanson Steven , Anderson Thomas , Bershad Brian , Borriello Gaetano , Gribble Steven , Wetherall David
Published: January 2005

Pervasive computing provides an attractive vision for the future of computing. Computational power will be available everywhere. Mobile and stationary devices will dynamically connect and coordinate to seamlessly help people in accomplishing their tasks. For this vision to become a reality, developers must build applications that constantly adapt to a highly dynamic computing environment. To make the developers' task feasible, we present a system architecture for pervasive computing, called one.world. Our architecture provides an integrated and comprehensive framework for building pervasive applications. It includes services, such as discovery and migration, that help to build applications and directly simplify the task of coping with constant change. We describe our architecture and its programming model and reflect on our own and others' experiences with using it.
RFID Isn’t Science Fiction
Authors: Grossman Edward
Published: January 2005

For those of you who read my editor’s note last month, you’ll recall I’m throwing this space open for comment: What should the editor’s note page be used for? Orienting you to the issue you’re about to read, highlighting some of the sights to see? Should I give some context as to how our Editorial Advisory Board grappled with the topic of the month’s special report? Or should we do away with the editor’s note altogether?
News 2.0
Authors: Grossman Edward
Published: January 2005

Ever notice how many people walk around carrying something on their backs? From bows and arrows and bales of hay to tripods and water bags, it’s the best way to go about your business while making a quiet statement about who you are. As it’s the computing age, after all, why not sling a roll-up monitor or TV over your shoulder when you leave home for the day? After all, it makes quite a different statement than lugging a no-skid yoga mat everywhere, and it’s a lot more useful to the technorati.
Kode Vicious to the Rescue
Authors: Neville-Neil George
Published: January 2005

Dear Kode Vicious, Where I work we use a mixture of C++ code, Python, and shell scripts in our product. I always have a hard time trying to figure out when it’s appropriate to use which for a certain job. Do you code in only assembler and C, or is this a problem for you as well?
Electronic Voting Systems: the Good, the Bad, and the Stupid
Authors: Simons Barbara
Published: January 2005

As a result of the Florida 2000 election fiasco, some people concluded that paper ballots simply couldn’t be counted. Instead, paperless computerized voting systems were touted as the solution to “the Florida problem.” Replacing hanging chads with 21st century technology, proponents claimed, would result in accurate election counts and machines that were virtually impossible to rig. Furthermore, with nothing to hand-count and no drawn-out recounts to worry about, computerized voting systems were expected to enable the reporting of results shortly after the polls had closed.
Review of “Dynamic Reconfiguration: Architectures and Algorithms by Ramachandran Vaidyanathan and Jerry L. Trahan”. Plenum Publishing, 2003, ISBN 0-306-48189-8.
Authors: Ektare Arun
Published: January 2005

Review of “Dynamic Reconfiguration: Architectures and Algorithms by Ramachandran Vaidyanathan and Jerry L. Trahan”. Plenum Publishing, 2003, ISBN 0-306-48189-8.
Measuring cache freshness by additive age
Authors: Ling Yibei , Chen Wai
Published: January 2005

Motivated by the work of cache freshness by Cho and Garcia-Molina [2], we present a new metric called additive age as an extension of existing freshness metrics. The additive age, being formulated somewhat differently, deviates from existing freshness metrics in its ability to better quantify the impact of frequently updated content on cache freshness. Mathematical result shows that the long-run average additive age is proportional to λT2, where λ is the change rate of source content, and T the refresh interval. This short paper briefly reviews the key elements of Cho and Garcia-Molina's work and simplifies their derivation by using renewal reward theory, with a focus on formulation of the notion of additive age.
DCFS
Authors: Xu Zhou , Xialiang Lu , Mengshu Hou
Published: January 2005

This paper presents a novel distributed cooperative fault-tolerance storage mechanism (DCFS) based on file replication and XOR verification. By using XOR verification files, DCFS makes a group of files which are distributed among different hosts cooperative, so that not only a single file in the group can use its XOR verification files to improve its own availability, but also the availability of the group can be improved greatly. Using the graph description of DCFS, we present the principle of DCFS and give a quantitative analysis to its performance. And experimental results have provided evidence of high fault-tolerance of DCFS.
Improvement of authenaticated multiple-key agreement protocol
Authors: Chen Bi-Hui
Published: January 2005

Recently, Yen and Joye showed that Harn and Lin's authenticated multiple-key agreement protocol is insecure against forgery and consequently proposed a revised protocol to repair it. Later, Wu et al. showed that Yen-Joye revision is also insecure and therefore an improved protocol was proposed. However, Wu et al.'s protocol violates the original requirement in which no one-way hash function is needed. On the other hand, in order to overcome Yen-Joye and Wu et al.'s attacks, Harn and Lin proposed a modified version by modifying the signature signing equation. But the modified version increases one exponentiation in the verification equation. Afterward Zhou et al. showed that the second Harh-Lin protocol is insecure against impersonation attack, i. e., a cheater can impersonate a valid user to execute the protocol successfully and obtains parts of the valid session keys. Then they proposed an improved version to enhance the second Harh-Lin protocol. In this paper, we first show that Zhou et al.'s protocol still suffers the impersonation attack, then we propose an improved scheme that is secure against forgery and doesn't involve any one-way hash function. Compared with all above modified versions, our scheme is secure and efficient.
New application of reliable agreement
Authors: Yan Kuo-Qin , Wang Shu-Ching , Chiang Mao-Lun
Published: January 2005

Due to the enterprise internationalization nowadays, each sub-company of the enterprise is located in different place. Under such circumstances, each sub-company must better itself with greater power and ability through coordination. Unfortunately, malicious hacker possibly fakes the communications between the sub-companies. The messages from sub-company might be changed in an unsecured environment. Thus, this paper proposes the Two-Phase Agreement (TPA) protocol to make easy the sub-companies' communication with the main-company or decision-making in company conference.
A Conversation with Bruce Lindsay
Authors: Bourne Steve
Published: January 2005

Designing for failure may be the key to success.
Oops! Coping with Human Error in IT Systems
Authors: Brown Aaron B.
Published: January 2005

Human operator error is one of the most insidious sources of failure and data loss in today’s IT environments. In early 2001, Microsoft suffered a nearly 24-hour outage in its Web properties as a result of a human error made while configuring a name resolution system. Later that year, an hour of trading on the Nasdaq stock exchange was disrupted because of a technicians mistake while testing a development system. More recently, human error has been blamed for outages in instant messaging networks, for security and privacy breaches, and for banking system failures.
Interworking internet telephony and wireless telecommunications networks
Authors: Lennox Jonathan , Murakami Kazutaka , Karaul Mehmet , La Porta Thomas F.
Published: January 2005

Internet telephony and mobile telephony are both growing very rapidly. Directly interworking the two presents significant advantages over connecting them through an intermediate PSTN link. We propose three novel schemes for the most complex aspect of the interworking: call delivery from an Internet telephony (SIP) terminal to a mobile telephony (UMTS) terminal. We then evaluate the proposals both qualitatively and quantitatively. However, existing equipment may not support packet interfaces needed for such interworking. Therefore, we also consider techniques for backward compatibility, and analyze their performance as well.
Fast handovers and context transfers in mobile networks
Authors: Koodli Rajeev , Perkins Charles E.
Published: January 2005

We describe recent work enabling fast handovers and context transfer between access routers offering Internet connectivity for mobile (often wireless) nodes. We present our framework for engineering general context transfer solutions, and a protocol which uses the framework to provide a simple yet general mechanism for carrying out context transfers during handovers. Since our mechanism operates at the network level, we expect that it will be the most expedient way to provide for seamless handovers between heterogeneous networks. We report our results which show that fast handovers with context transfer at the network layer can support uninterrupted voice over IP (VoIP). Thus, our context transfer framework will catalyze the arrival of a unified wireless telecommunications network, with voice and data connectivity anytime, anywhere. Towards that end, we describe how our results and context transfer framework relate to other work within the IETF.
A cooperative approach to user mobility
Authors: Kravets Robin , Carter Casey , Magalhães Luiz
Published: January 2005

We propose a networking model that treats a user's set of personal devices as a MObile grouPEd Device, a MOPED, which appears as a single entity to the rest of the Internet. All communication for a user is directed to this point of presence. As the user moves through different environments, the devices cooperate to provide the user with access to all available communication resources. We present the basic networking functionality necessary to enable the operation of MOPEDs and their integration into the Internet. We introduce a middleware layer to extend IP routing to work with MOPEDs and a lightweight IP encapsulation protocol, Multipath Routing enCAPsulation (MRCAP), used to implement that middleware.
Prediction-based monitoring in sensor networks
Authors: Goel Samir , Imielinski Tomasz
Published: January 2005

In this paper we discuss the problem of monitoring data sensed in large sensor networks. A sensor typically runs on a battery having a limited lifetime. In order to increase the lifetime of a sensor it is important that the mechanisms used in monitoring them be energy-efficient. In this paper, we propose a new paradigm called Prediction-based monitoring for energy-efficient monitoring. We show that the paradigm can be visualized as a watching of a "sensor movie" and that concepts from MPEG may be applied to it. We have implemented the proposed algorithms in a test bed of Rene Motes [2]. Experimental results show that the proposed solutions cut down the energy consumption by more than 5 times, considerably increasing sensor lifetimes, and thereby, the lifetime of the networks formed from these sensors.
Using a web-based categorization approach to generate thematic metadata from texts
Authors: Huang Chien-Chung , Chuang Shui-Lung , Chien Lee-Feng
Published: January 2005

Conventional tools for automatic metadata creation mostly extract named entities or text segments from texts and annotate them with information about persons, locations, dates, and so on. However, this kind of entity type information is often insufficient for machines to understand the facts contained in the texts, thus precluding the possibility of implementing more advanced, intelligent applications, such as concept-based search. In this work, we try to create more refined thematic metadata inherent in texts. Based on Web resource mining, our approach acquires training corpora necessary to describe both the thematic categories and the metadata extracted from the texts. The approach then finds the corresponding relationships among them by means of categorization and thus generates thematic metadata for the textual data. Experimental results confirm the potential and wide adaptability of our approach.
A manner of speaking
Authors: Schindler Esther
Published: January 2005

Over time, society establishes the etiquette for new technologies. But can it adjust fast enough?
Secure program execution via dynamic information flow tracking
Authors: Suh G. Edward , Lee Jae W. , Zhang David , Devadas Srinivas
Published: January 2005

We present a simple architectural mechanism called dynamic information flow tracking that can significantly improve the security of computing systems with negligible performance overhead. Dynamic information flow tracking protects programs against malicious software attacks by identifying spurious information flows from untrusted I/O and restricting the usage of the spurious information.Every security attack to take control of a program needs to transfer the program's control to malevolent code. In our approach, the operating system identifies a set of input channels as spurious, and the processor tracks all information flows from those inputs. A broad range of attacks are effectively defeated by checking the use of the spurious values as instructions and pointers.Our protection is transparent to users or application programmers; the executables can be used without any modification. Also, our scheme only incurs, on average, a memory overhead of 1.4% and a performance overhead of 1.1%.
Locality phase prediction
Authors: Shen Xipeng , Zhong Yutao , Ding Chen
Published: January 2005

As computer memory hierarchy becomes adaptive, its performance increasingly depends on forecasting the dynamic program locality. This paper presents a method that predicts the locality phases of a program by a combination of locality profiling and run-time prediction. By profiling a training input, it identifies locality phases by sifting through all accesses to all data elements using variable-distance sampling, wavelet filtering, and optimal phase partitioning. It then constructs a phase hierarchy through grammar compression. Finally, it inserts phase markers into the program using binary rewriting. When the instrumented program runs, it uses the first few executions of a phase to predict all its later executions.Compared with existing methods based on program code and execution intervals, locality phase prediction is unique because it uses locality profiles, and it marks phase boundaries in program code. The second half of the paper presents a comprehensive evaluation. It measures the accuracy and the coverage of the new technique and compares it with best known run-time methods. It measures its benefit in adaptive cache resizing and memory remapping. Finally, it compares the automatic analysis with manual phase marking. The results show that locality phase prediction is well suited for identifying large, recurring phases in complex programs.
Compiler orchestrated prefetching via speculation and predication
Authors: Rabbah Rodric M. , Sandanagobalane Hariharan , Ekpanyapong Mongkol , Wong Weng-Fai
Published: January 2005

This paper introduces a compiler orchestrated prefetching system as a unified framework geared toward ameliorating the gap between processing speeds and memory access latencies. We focus the scope of the optimization on specific subsets of the program dependence graph that succinctly characterize the memory access pattern of both regular array-based applications and irregular pointer-intensive programs. We illustrate how
program embedded precomputation via speculative execution
can accurately predict and effectively prefetch future memory references with negligible overhead. The proposed techniques reduce the total running time of seven SPEC benchmarks and two OLDEN benchmarks by 27% on an Itanium 2 processor. The improvements are in addition to several state-of-the-art optimizations including software pipelining and data prefetching. In addition, we use cycle-accurate simulations to identify important and lightweight architectural innovations that further mitigate the memory system bottleneck. In particular, we focus on the notoriously challenging class of pointer-chasing applications, and demonstrate how they may benefit from a novel scheme of
it sentineled prefetching
. Our results for twelve SPEC benchmarks demonstrate that 45% of the processor stalls that are caused by the memory system are avoidable. The techniques in this paper can effectively mask long memory latencies with little instruction overhead, and can readily contribute to the performance of processors today.
Software prefetching for mark-sweep garbage collection
Authors: Cher Chen-Yong , Hosking Antony L. , Vijaykumar T. N.
Published: January 2005

Tracing garbage collectors traverse references from live program variables, transitively tracing out the closure of live objects. Memory accesses incurred during tracing are essentially random: a given object may contain references to any other object. Since application heaps are typically much larger than hardware caches, tracing results in many cache misses. Technology trends will make cache misses more important, so tracing is a prime target for prefetching.Simulation of Java benchmarks running with the Boehm-De-mers-Weiser mark-sweep garbage collector for a projected hardware platform reveal high tracing overhead (up to 65% of elapsed time), and that cache misses are a problem. Applying Boehm's default prefetching strategy yields improvements in execution time (16% on average with incremental/generational collection for GC-intensive benchmarks), but analysis shows that his strategy suffers from significant timing problems: prefetches that occur too early or too late relative to their matching loads. This analysis drives development of a new prefetching strategy that yields up to
three times
the performance improvement of Boehm's strategy for GC-intensive benchmark (27% average speedup), and achieves performance close to that of perfect timing
ie
, few misses for tracing accesses) on some benchmarks. Validating these simulation results with live runs on current hardware produces average speedup of 6% for the new strategy on GC-intensive benchmarks with a GC configuration that tightly controls heap growth. In contrast, Boehm's default prefetching strategy is ineffective on this platform.