bluuebunny/crossref_metadata_2025 huggingface dataset:
Occurrence and direct control potential of parasitoids and predators of the fall armyworm (Lepidoptera: Noctuidae) on maize in the subtropical lowlands of Mexico
Authors: Hoballah Maria Elena , Degen Thomas , Bergvinson David , Savidan Anita , Tamò Cristina , Turlings Ted C. J.
Published: February 2004

Abstract  1 Native natural enemies have the potential to control fall armyworm Spodoptera frugiperda (Smith) in tropical maize grown in Mexico, where this insect pest causes severe economic losses to farmers. It has been proposed that enhancing herbivore‐induced volatile emissions in maize plants may help to increase the effectiveness of natural enemies, which use these volatiles to locate their prey. This will only be of immediate benefit to farmers if the activity of the natural enemies results in a direct reduction in herbivory. Here we report on field surveys for the most common natural enemies in a tropical maize‐growing region in Mexico and the potential effects of these enemies on herbivory by fall armyworm.

2 Caterpillars were collected in maize fields near Poza Rica in the state of Veracruz during January and February 1999, 2000 and 2001. Plants were either naturally infested by S. frugiperda, or artificially infested with laboratory‐reared larvae. Ten species of parasitoids emerged from the collected larvae and eight species of predators that are known to feed on larvae and eggs were observed on the plants. Campoletis sonorensis (Cameron) (Hymenoptera: Ichneumonidae) was the dominant parasitoid species, in 1999 and 2001.

3 Of the nine larval parasitoids collected, six (all solitary) are known to reduce herbivory, whereas one causes the host to eat more (for two species this is not known). This implies that enhancing the effectiveness of solitary endoparasitoids may benefit subsistence farmers in developing countries by immediately reducing herbivory. The overall benefit for the plant resulting from parasitoid activity also has important implications for the evolutionary role of parasitoids in contributing to selection pressures that shape indirect defences in plants.
Stand‐level distribution and movement of Platypus quercivorus adults and patterns of incidence of new infestation
Authors: Esaki Kojiro , Kato Kenryu , Kamata Naoto
Published: February 2004

Abstract  1 Flying populations of an ambrosia beetle, Platypus quercivorus (Murayama), a vector of an ambrosia fungus Raffaelea quercivora, which causes deciduous oak diebacks in Japan, were determined by sticky screen traps.

2 Platypus quercivorus beetles tended to move upwards along slopes. The highest concentrations of flying beetles usually occured at the upper forest margins.

3 During the period when the number of flying beetles was increasing, the incidence of newly infested trees spread from the epicentre into the forest. During the period when the number of flying beetles was decreasing, the epicentre shrank into the upper forest edge. Newly infested trees did not occur in this period because most trees had already been infested.

4 Near the upper forest edge, where many beetles were highly concentrated throughout the season, the number of new entry holes decreased greatly after the initial attack early in the season, although many adults were present throughout the period.
Trade Wars: The Exaggerated Impact of Trade in Economic Debate
Authors: Freeman Richard B.
Published: February 2004

The rules governing trade and capital flows have been at the centre of controversy as globalisation has proceeded. One reason is the belief that trade and capital flows have massive effects on the labour market – either positive, per the claims of international financial institutions and free trade enthusiasts, or negative, per the ubiquitous protestors at WTO, IMF and World Bank meetings demanding global labour standards. Comparing the claims made in this debate with the outcomes of trade agreements, this paper finds that the debate has exaggerated the effects of trade on economies and the labour market. Changes in trade policy have had modest impacts on the labour market. Other aspects of globalisation – immigration, capital flows and technology transfer – have greater impacts, with volatile capital flows creating great risk for the well‐being of workers. As for labour standards, global standards do not threaten the comparative advantage of developing countries nor do poor labour standards create a ‘race to the bottom’.
Globalisation and Economic Growth: A Historical Perspective
Authors: Crafts Nicholas
Published: February 2004

This paper reviews the historical evidence on the relationship between globalisation and economic growth. Divergence in the growth of income and industrialisation in the twentieth century is documented but it is also noted that international income inequality appears to have decreased since about 1870 and that long‐run trends in the Human Development Index are much less pessimistic about the experience of developing countries. It is argued that trade liberalisation has been good for growth on average but that successful capital liberalisation requires high institutional quality and that the developmental state may have an important role to play in the early stages of development. The recent claim by Robert Lucas that the 21st century will see a massive reduction in income inequality across countries in a globalised world economy is sceptically discussed in the context of empirical evidence that bad institutions are often persistent and that geography is still a major factor in explaining international income differences.
Developing Countries as Plaintiffs and Defendants in GATT/WTO Trade Disputes
Authors: Bown Chad P.
Published: February 2004

Developing countries have been increasing their participation in the formal institutions and proceedings of the multilateral trading system. A prominent example is their more frequent involvement as defendants and plaintiffs in GATT/WTO trade disputes. This paper provides an initial economic appraisal of developing country performance in the GATT/WTO dispute settlement system. We measure the economic resolution of these disputes through trade liberalisation gains, and our results suggest that developing country plaintiffs have had more success under WTO disputes than was the case under the GATT. We also document evidence on potential determinants of this success: the capacity for plaintiffs to make credible retaliatory threats and the guilty determinations by GATT/WTO panels. Finally, there is also some evidence that developing countries have recognised the importance of retaliatory threats and have responded by changing their pattern of dispute initiation under the WTO to better take advantage of the instances in which they have sufficient leverage to threaten retaliation and induce compliance with GATT/WTO obligations.
Halving Poverty by Doubling Aid: Is There Reason for Optimism?
Authors: Langhammer Rolf J.
Published: February 2004

This paper criticises the World Bank as overly optimistic with respect to its ability to fine‐tune development aid and to focus it on countries with ‘good’ policies rather than on countries with ‘poor’ policies in order to raise its effectiveness. It is shown that recipient regions showed very different patterns of aid inflows and economic growth in the past and that aid flows yielded the highest correlation to growth when their magnitudes shrank. It is furthermore argued that categorising countries by quality of domestic policies is not only questionable at a given point of time especially in countries with failing governmental institutions and open borders as in many African countries. It suffers also from incentive problems so that countries receiving more aid can become victims of changes in their domestic policies which are more permissive and etatist to the disadvantage of private agents. The paper instead pleads for a shift to aid policies decoupled from country‐specifics and more oriented to fundamental ‘beyond border’ problems of the well‐being of the poor. An international endowment fund under supranational law should finance research and implementation of research findings related to common international goods as it was suggested by Sachs concerning aids and tropical disease research.
We Don’t Need a Microscope to Explore the Chimpanzee's Mind
Authors: Povinelli Daniel J. , Vonk Jennifer
Published: February 2004

Abstract:  The question of whether chimpanzees, like humans, reason about unobservable mental states remains highly controversial. On one account, chimpanzees are seen as possessing a psychological system for social cognition that represents and reasons about behaviors alone. A competing account allows that the chimpanzee's social cognition system additionally construes the behaviors it represents in terms of mental states. Because the range of behaviors that each of the two systems can generate is not currently known, and because the latter system depends upon the former, determining the presence of this latter system in chimpanzees is a far more difficult task than has been assumed. We call for recognition of this problem, and a shift from experimental paradigms that cannot resolve this question, to ones that might allow researchers to intelligently determine when it is necessary to postulate the presence of a system which reasons about both behavior and mental states.
Having Concepts: a Brief Refutation of the Twentieth Century
Authors: Fodor Jerry
Published: February 2004

Abstract: A certain ‘pragmatist’ view of concept possession has defined the mainstream of Anglophone philosophy of language/mind for decades: namely, that to have the concept C is to be able to distinguish Cs from non‐Cs, and/or to recognize the validity of certain C‐involving inferences. The present paper offers three arguments why no such account could be viable. An alternative ‘Cartesian’ view is outlined, according to which having C is being able to think about Cs ‘as such’. Some consequences of the proposed paradigm shift are briefly considered.
Remarks on Fodor on Having Concepts
Authors: Weiskopf Daniel A. , Bechtel William
Published: February 2004

Abstract: Fodor offers a novel argument against Bare‐bones Concept Pragmatism (BCP). He alleges that there are two circularities in BCP's account of concept possession: a circularity in explaining concept possession in terms of the capacity to sort; and a circularity in explaining concept possession in terms of the capacity to draw inferences. We argue that neither of these circles is real.
Putting Concepts to Work: Some Thoughts for the Twentyfirst Century
Authors: Prinz Jesse , Clark Andy
Published: February 2004

Abstract:  Fodor's theory makes thinking prior to doing. It allows for an inactive agent or pure reflector, and for agents whose actions in various ways seem to float free of their own conceptual repertoires. We show that naturally evolved creatures are not like that. In the real world, thinking is always and everywhere about doing. The point of having a brain is to guide the actions of embodied beings in a complex material world. Some of those actions are, to be sure, more recondite than others. But in every case the contents of thoughts still look to depend, in some non‐unique but vitally important way, on the kinds of doings they support.
Fodor's Ingratitude and Change of Heart?
Authors: Rey Georges
Published: February 2004

Abstract:  One would have thought that Fodor's justly famous computational views about the mind and his covariation approaches to content owed a lot to the twentieth century that he now reviles. On the other hand, a number of lines he pursues in the target article make one wonder whether he hasn’t perhaps changed his mind about those famous views. Specifically, I argue that his own theory of content is open to the very same objections he raises against ‘sorting’ theories, and that the supposed circularity in implicit definitions of logical particles can easily be avoided by the very functional/computational definitions that he fathered decades ago. Fodor's rejection here of sorting and implicit definition does make one worry that he is now opting for what seems the only atomistic alternative that would seem to be left, the first‐person meaning mysticism of the very Cartesian sort he now claims to favor, but from which I would have thought twentieth century role and discrimination views were a welcome relief. Despite all these worries, however, I concede that one could probably do worse than assume for the nonce that meaning is atomic, or, anyway, unanalyzed, and get on with investigating the mind on that basis—but keeping the options open.
Interrelations: Concepts, Knowledge, Reference and Structure
Authors: Peacocke Christopher
Published: February 2004

Abstract:  This paper has five theses, which are intended to address the claims in Jerry Fodor's paper. (1) The question arises of the relation between the philosophical theory of concepts and epistemology. Neither is explanatorily prior to the other. Rather, each relies implicitly on distinctions drawn from the other. To explain what makes something knowledge, we need distinctions drawn from the theory of concepts. To explain the attitudes mentioned in a theory of concepts, we need to use the notion of knowledge. (2) Concepts can have a normative dimension without their nature being interpretation‐dependent, and without their nature being mind‐dependent. The normative dimension traces back instead to the role of truth as a constitutive aim of judgement. (3) Conceptual combination is to be explained at the level of reference and semantic value. When we respect this fact, there is no difficulty in explaining compositionality for epistemically‐constrained concepts. (4) Epistemically‐constrained theories of concepts are committed to the applicability of the notion of the a priori. They are not committed to the applicability of the notion of analyticity, where this is construed as truth purely in virtue of meaning or the identity of concepts. (5) Possession of a concept has causal‐explanatory powers, whether given by a possession condition in the form presented in A Study of Concepts, or by possession of an implicit conception. A possession‐condition theory of concepts need not be a form of dispositionalism.
Workplace factors leading to planned reduction of clinical work among emergency physicians
Authors: Crook Heather D , Taylor David McD , Pallant Julie F , Cameron Peter A
Published: February 2004

Objective:  There is anecdotal evidence that ACEM Fellows are reducing or planning to reduce their clinical workload. We investigated the extent of, and reasons for, these reductions.

Methods:  An anonymous, cross‐sectional postal survey utilizing a study‐specific questionnaire.

Results:  Three hundred and twenty‐three Fellows (63.5%) responded. Most were recently graduated males. In the last 5 years, the mean number of clinical hours worked per week has reduced significantly (P < 0.001) for both junior (40.6–28.9 h) and senior Fellows (30.4–23.1 h). Further significant (P < 0.001) reductions are planned. The most frequently reported reasons for reducing clinical workload were excessive workload, family life and emotional health effects, shift work and work stress. The most stressful aspects of work reported were access block, dealing with management, insufficient staffing, workload pressures and staff supervision. Clinical work reportedly impacts most upon family life, social life and emotional health.

Conclusions:  Fellows are significantly reducing their clinical workload largely in response to excessive workload and lack of resources. These findings have important implications for professional longevity and work force planning. Re‐evaluation of workplace practice, especially identified stressors, is indicated.
The psychological health of emergency physicians in Australasia
Authors: Taylor David McD , Pallant Julie F , Crook Heather D , Cameron Peter A
Published: February 2004

Objective:  To evaluate the psychological health of ACEM Fellows and the important factors that impact on this health.

Methods:  A cross‐sectional, mail survey utilizing validated psychological instruments.

Results:  Three hundred and twenty‐three (63.5%) of 510 physicians responded. Most were recently graduated males. Compared to a general population sample, their psychological health was good with greater optimism and mastery (P < 0.001), less anxiety, depression and physical symptoms (P < 0.001), better life satisfaction (P = 0.04) and similar perceived stress (P = 0.20). The mean work stress score (1 = low, 10 = high) was 5.6 ± 2.1 (moderate stress) although 63 (19.5%) had very high scores (8–10). The mean work satisfaction score was 6.3 ± 2.1 (moderate satisfaction) although 43 (13.3%) had very low scores (1–3). Perceptions of control over hours worked and mix of professional activities were positively associated with work and life satisfaction (P < 0.001) and negatively associated with work stress and measures of wellbeing (P < 0.001). Most employed adaptive coping strategies. However, maladaptive strategies (alcohol/drugs, denial, disengagement) were positively associated with anxiety, depression and stress (P < 0.001).

Conclusions:  Most physicians are psychologically healthy. However, there appears to be a subgroup that is not thriving. Workplace stress should be addressed promptly and greater flexibility provided over hours worked and mix of professional activities.
Pharmacological therapy of acute cardiogenic pulmonary oedema in the emergency department
Authors: Graham Colin A
Published: February 2004

This paper critically reviews the major drug types that are currently used in the management of acute cardiogenic pulmonary oedema. As decompensated heart failure becomes an increasingly common problem in emergency departments in the developed world, optimization of emergency drug therapy for these critically ill patients is essential. The evidence base for ‘routine therapy’ in the ED is considered. The review also briefly considers emerging pharmacological therapies that may have an impact on future management of cardiogenic pulmonary oedema.
Cyclooxygenase‐2 inhibitors: Do they have a role in emergency department prescribing?
Authors: Wilton Tanya
Published: February 2004

Cyclooxygenase‐2 selective inhibitors (COXIB or CSI) have been released with a fanfare as efficacious and safer alternatives to traditional non‐steroidal anti‐inflammatory drugs. They purport to offer equivalent degrees of analgesia and an improved safety profile. COXIB currently available in Australasia are celecoxib (Celebrex), rofecoxib (Vioxx) and etoricoxib (Arcoxia). This review discusses the pharmacology of these agents and reviews recent literature regarding their effectiveness and safety. It endeavours to answer the question ‘Should we be using COXIB in emergency departments in Australasia’?
Anaphylaxis to trimethoprim: An under‐appreciated risk in acute medical care
Authors: Nordstrand Indra AJ
Published: February 2004

Anaphylaxis is a severe, systemic allergic reaction, which is frequently unexpected and carries a high mortality risk as a medical emergency. Anaphylaxis to trimethoprim is not a well recognized event. Since trimethoprim represents the leading antibiotic for the treatment of urinary tract infections, its potential to cause anaphylaxis needs to be recognized, whether alone or as the ‘active’ ingredient in cotrimoxazole (trimethoprim‐sulphamethoxazole combination), by those prescribing it and those providing acute care. A case of probable anaphylaxis following trimethoprim ingestion is presented with discussion supporting its potency including evidence at an immunological level highlighting its under‐appreciated risk in acute medical care.
Pilot study of metropolitan emergency department workload complexity
Authors: Sprivulis Peter
Published: February 2004

Objective:  Assessment of emergency department (ED) patient complexity using the number of procedures, investigations or consultations (PICsum).

Methods:  Retrospective analysis of 12 months of data from an adult metropolitan teaching hospital ED.

Results:  A bimodal distribution of PICsum (modal peaks, PICsum 1 and 7) was observed in all Australasian Triage Scale, disposition, mode of arrival, age and referral source groups. Patients requiring a minimum of two procedures or a minimum of two investigations or a minimum of two consultations (Min2 patients) comprised 59% (95% CI 58.5–59.5) of total patients 93% (95% CI 92.5–93.8) of total PICsum. Age is highly correlated with Mean PICsum (Pearson r = 0.98, P < 0.001) and the proportion of Min2 patients (Pearson r = 0.98, P < 0.001).

Conclusions:  An intuitive partition in the complexity distribution is identified at up to one procedure, one investigation and one consultation. Patient age is correlated with complexity and ED age distribution may be a useful proxy for complexity, particularly if used in conjunction with validated age versus complexity tables.
Molecular Evolution of the SARS Coronavirus During the Course of the SARS Epidemic in China
Authors:   The Chinese SARS Molecular Epidemiology Consortium
Published: February 2004

Sixty-one SARS coronavirus genomic sequences derived from the early, middle, and late phases of the severe acute respiratory syndrome (SARS) epidemic were analyzed together with two viral sequences from palm civets. Genotypes characteristic of each phase were discovered, and the earliest genotypes were similar to the animal SARS-like coronaviruses. Major deletions were observed in the Orf8 region of the genome, both at the start and the end of the epidemic. The neutral mutation rate of the viral genome was constant but the amino acid substitution rate of the coding sequences slowed during the course of the epidemic. The spike protein showed the strongest initial responses to positive selection pressures, followed by subsequent purifying selection and eventual stabilization.
Quality of service in an information economy
Authors: Braumandl R. , Kemper A. , Kossmann D.
Published: February 2004

Accessing and processing distributed data sources have become important factors for businesses today. This is especially true for the emerging virtual enterprises with their data and processing capabilities spread across the Internet. Unfortunately, however, query processing on the Internet is not predictable and robust enough to meet the requirements of many business applications. For instance, the response time of a query can be unexpectedly high; or the monetary cost might be too high if the partners charge for the usage of their data or processing capabilities; or the result of the query might be useless because it is based on outdated data or only on parts (rather than all) of the available data. In this work, we show how a distributed query processor can be extended in order to support quality of service (QoS) guarantees. We propose ways to integrate QoS management into the various phases of query processing: (1) Query optimization uses a multi-dimensional assessment (cost, time and result quality) of query plans, (2) query plan instantiation comprises an admission control for sub-plans, and (3) during query plan execution the QoS of the query is monitored and a fuzzy controller initiates repairing actions if needed. The goal of our work is to provide an initial step towards QoS management in distributed query processing systems and do significantly better than current distributed database systems, which are based on a best-effort policy.
Efficient scheduling of Internet banner advertisements
Authors: Amiri Ali , Menon Syam
Published: February 2004

Despite the slowdown in the economy, advertisement revenue remains a significant source of income for many Internet-based organizations. Banner advertisements form a critical component of this income, accounting for 40 to 50 percent of the total revenue. There are considerable gains to be realized through the efficient scheduling of banner advertisements. This problem has been observed to be intractable via traditional optimization techniques, and has received only limited attention in the literature. This paper presents a procedure to generate advertisement schedules under the most commonly used advertisement pricing scheme---the CPM model. The solution approach is based on Lagrangean decomposition and is seen to provide extremely good advertisement schedules in a relatively short period of time, taking only a few hundred seconds of elapsed time on a 450 MHz PC compared to a few thousand seconds of CPU time on a workstation that other approaches need. Additionally, this approach can be incorporated into an actual implementation with minimal alterations and hence is of particular interest.
Architecture and performance of server-directed transcoding
Authors: Knutsson Björn , Lu Honghui , Mogul Jeffrey , Hopkins Bryan
Published: February 2004

Proxy-based transcoding adapts Web content to be a better match for client capabilities (such as screen size and color depth) and last-hop bandwidths. Traditional transcoding breaks the end-to-end model of the Web, because the proxy does not know the semantics of the content.
Server-directed transcoding
preserves end-to-end semantics while supporting aggressive content transformations.We show how server-directed transcoding can be integrated into the HTTP protocol and into the implementation of a proxy. We discuss several useful transformations for image content, and present measurements of the performance impacts. Our results demonstrate that server-directed transcoding is a natural extension to HTTP, can be implemented without great complexity, and can provide good performance when carefully implemented.
Escape analysis for Java
TM
Authors: Blanchet Bruno
Published: February 2004

Escape analysis is a static analysis that determines whether the lifetime of data may exceed its static scope.This paper first presents the design and correctness proof of an escape analysis for Java
TM
. This analysis is interprocedural, context sensitive, and as flow-sensitive as the static single assignment form. So, assignments to object fields are analyzed in a flow-insensitive manner. Since Java is an imperative language, the effect of assignments must be precisely determined. This goal is achieved thanks to our technique using two interdependent analyses, one forward, one backward. We introduce a new method to prove the correctness of this analysis, using aliases as an intermediate step. We use integers to represent the escaping parts of values, which leads to a fast and precise analysis.Our implementation [Blanchet 1999], which applies to the whole Java language, is then presented. Escape analysis is applied to stack allocation and synchronization elimination. In our benchmarks, we stack allocate 13% to 95% of data, eliminate more than 20% of synchronizations on most programs (94% and 99% on two examples) and get up to 43% runtime decrease (21% on average). Our detailed experimental study on large programs shows that the improvement comes more from the decrease of the garbage collection and allocation times than from improvements on data locality, contrary to what happened for ML. This comes from the difference in the garbage collectors.
Extending Java for high-level Web service construction
Authors: Christensen Aske Simon , Møller Anders , Schwartzbach Michael I.
Published: February 2004

We incorporate innovations from the  project into the Java language to provide high-level features for Web service programming. The resulting language, JWIG, contains an advanced session model and a flexible mechanism for dynamic construction of XML documents, in particular XHTML. To support program development we provide a suite of program analyses that at compile time verify for a given program that no runtime errors can occur while building documents or receiving form input, and that all documents being shown are valid according to the document type definition for XHTML 1.0.We compare JWIG with Servlets and JSP which are widely used Web service development platforms. Our implementation and evaluation of JWIG indicate that the language extensions can simplify the program structure and that the analyses are sufficiently fast and precise to be practically useful.
Stack allocation and synchronization optimizations for Java using escape analysis
Authors: Choi Jong-Deok , Gupta Manish , Serrano Mauricio J. , Sreedhar Vugranam C. , Midkiff Samuel P.
Published: February 2004

This article presents an
escape analysis
framework for Java to determine (1) if an object is not reachable after its method of creation returns, allowing the object to be allocated on the stack, and (2) if an object is reachable only from a single thread during its lifetime, allowing unnecessary synchronization operations on that object to be removed. We introduce a new program abstraction for escape analysis, the
connection graph
, that is used to establish reachability relationships between objects and object references. We show that the connection graph can be succinctly summarized for each method such that the same summary information may be used in different calling contexts without introducing imprecision into the analysis. We present an interprocedural algorithm that uses the above property to efficiently compute the connection graph and identify the nonescaping objects for methods and threads. The experimental results, from a prototype implementation of our framework in the IBM High Performance Compiler for Java, are very promising. The percentage of objects that may be allocated on the stack exceeds 70% of all dynamically created objects in the user code in three out of the ten benchmarks (with a median of 19%); 11% to 92% of all mutex lock operations are eliminated in those 10 programs (with a median of 51%), and the overall execution time reduction ranges from 2% to 23% (with a median of 7%) on a 333-MHz PowerPC workstation with 512 MB memory.
The emotion commotion
Authors: Marcus Aaron
Published: February 2004

The computer-human interaction (CHI) community's interest in emotions is heating up. Beyond usability, professionals are taking part in provocative discussions of appeal, desire, pleasure, even frustration---and, no doubt, pain. Before we get carried away, let's review the territory.
Information architecture
Authors: Gill Kathy
Published: February 2004

Information Architecture: Blueprints for the Web

Christina Wodtke

New Riders, Indianapolis, 2003

ISBN 0-7357-1250-6 $29.99
Conference preview and calendar
Authors: Campbell Marisa
Published: February 2004

ACM Conference on Universal Usability 2003
November 10-11, 2003
Vancouver B.C., Canada
Rising sun
Authors: Barnes Stuart J. , Huff Sid L.
Published: February 2004

Applying technology acceptance theory to understand why iMode has become so popular in Japan, and whether its popularity will extend to the rest of the world.
The MP3 open standard and the music industry's response to Internet piracy
Authors: Easley Robert F. , Michel John G. , Devaraj Sarv
Published: February 2004

Can open standards motivate market leaders to accept new technology?
Balancing free speech and censorship
Authors: Peace A. Graham
Published: February 2004

Many universities do not consider the topic of censorship important enough to address in a formal way---but the legal and ethical risks of neglecting this issue should not be ignored.
A common theme for IT degree programs
Authors: Landry Jeffrey P. , Pardue J. Harold , Longenecker Herbert E. , Feinstein David F.
Published: February 2004

Effective IT curricula balances tradition with innovation. One way to enhance that balance is to examine the common threads in the various knowledge areas.
Great principles of computing
Authors: Denning Peter J.
Published: February 2004

The great principles of computing have been interred beneath layers of technology in our understanding and our teaching. It is time to set them free.
A sociopolitical look at open source
Authors: Glass Robert L.
Published: February 2004

Contemplating the sociological and political aspects of the open source movement.
The myth of diminishing firms
Authors: Sampson Geoffrey
Published: February 2004

Economist Ronald Coase was not suggesting that because the size of firms is tied to transaction costs, the lower transaction costs of e-commerce would cause e-businesses to grow smaller and smaller.
Introduction
Authors: Brown Maxine D.
Published: February 2004

E-scientists are moving from a processor-centric to a network-centric world with new levels of persistent collaboration over transoceanic distances and the ability to process, disseminate, and share vast stores of distributed data.
Transport protocols for high performance
Authors: Falk Aaron , Faber Ted , Bannister Joseph , Chien Andrew , Grossman Robert , Leigh Jason
Published: February 2004

The Explicit Control Protocol and other new congestion-control systems greatly improve application performance over a range of network infrastructure, including extremely high-speed and high-delay links. What then is next for TCP and other established but less-capable Internet protocols?
Data integration in a bandwidth-rich world
Authors: Foster Ian , Grossman Robert L.
Published: February 2004

Inexpensive storage and wide-area bandwidth (with prices for both declining at least as fast as Moore's Law) drive demand for middleware to integrate, correlate, compare, and mine local, remote, and distributed data.
The OptIPuter
Authors: Smarr Larry L. , Chien Andrew A. , DeFanti Tom , Leigh Jason , Papadopoulos Philip M.
Published: February 2004

This architecture/infrastructure of parallel optical networks couples data exploration, visualization, and collaboration technologies through IP at multi-gigabit speeds.
Data-intensive e-science frontier research
Authors: Newman Harvey B. , Ellisman Mark H. , Orcutt John A.
Published: February 2004

Large-scale e-science, including high-energy and nuclear physics, biomedical informatics, and Earth science, depend on an increasingly integrated, distributed cyberinfrastructure serving virtual organizations on a global scale.
Introduction to programming with Visual Basic
Authors: Conn Richard
Published: February 2004

This module is used as an introduction to computers and programming as tools to aid problem-solving. The computer programming language used in the course is Microsoft Visual Basic, but the concepts presented in this course (such as variables and constants) are found in other programming languages (such as Ada, C++, and Java) as well.
Software Systems Requirements
Authors: Conn Richard
Published: February 2004

This module describes course SWE 2623 on software systems requirements given at the School of Computing and Software Engineering Southern Polytechnic State University. The process of extracting, deriving, and validating software requirements from a customer are explored, including levels of user/customer involvement, effective means of documenting requirements, the dynamics of interviewing, and the development of requirements specifications interactively (via methods such as the Evolutionary Spiral Model, now required for all contractors by DoD Directive 5000.1). A large part of the course is devoted to problem domain modeling using current analysis methods and supporting tools, including rapid prototyping aids and UML. Requirements engineering methodologies, such as Consortium Requirements Engineering and Requirements-Based Testing, are examined. Formal methods employing languages such as Z and SPARK are discussed.
Quantitative analysis of the effects of robots on introductory Computer Science education
Authors: Fagin Barry S. , Merkle Laurence
Published: February 2004

We report the results of a year-long experiment in the use of robots to teach computer science. Our data set compares results from over 800 students on identical tests from both robotics and nonrobotics-based laboratory sessions. We also examine the effectiveness of robots in encouraging students to select computer science or computer engineering as a field of study. Our results are negative: test scores were lower in the robotics sections than in the nonrobotics ones, nor did the use of robots have any measurable effect on students' choice of discipline. We believe the most significant factor that accounts for this is the lack of a simulator for our robotics programming system. Students in robotics sections must run and debug their programs on robots during assigned lab times, and are therefore deprived of both reflective time and the rapid compile-run-debug cycle outside of class that is an important part of the learning process. We discuss this and other issues, and suggest directions for future work.
Teaching Software Engineering in a Compiler Project Course
Authors: Griswold William G.
Published: February 2004

A compiler course with a long-term project is a staple of many undergraduate computer science curricula, and often a cornerstone of a program's applied-engineering component. Software engineering expertise can help a student complete such a course, yet that expertise is often lacking. This problem can be addressed without detracting from the core class materials by integrating a few simple software engineering practices into the course. A domain-specific, risk-driven approach minimizes overhead and reinforces the compiler's material, while treating the project as a "real world" enterprise reinforces key engineering lessons. The method might be called "syntax-directed software engineering," being driven by specification centered around a BNF-style grammar. Engineering lessons are reinforced with general engineering principles and contextualization of the subject matter. The approach can be taught without substantial software engineering background. The domain-specific risk-driven software engineering approach can be applied in other courses such as operating systems by redesigning the practices around its domain.
An Infrastructure for Web-Based Computer-Assisted Learning
Authors: Joy Mike , Muzykantskii Boris , Rawles Simon , Evans Michael
Published: February 2004

We describe an initiative under way at Warwick to provide a technical foundation for computer-aided learning and computer-assisted assessment tools, which allows a rich dialogue sensitive to individual students' response patterns. The system distinguishes between dialogues for individual problems and the linking of problems. This enables a subject specialist to craft individual questions and units of learning material, while allowing the order of presentation of the units to depend on a student's interaction history. We develop a markup language, specified as an XML DTD, to enable the storage of data for use in such systems.
Clustering intrusion detection alarms to support root cause analysis
Authors: Julisch Klaus
Published: February 2004

It is a well-known problem that intrusion detection systems overload their human operators by triggering thousands of alarms per day. This paper presents a new approach for handling intrusion detection alarms more efficiently. Central to this approach is the notion that each alarm occurs for a reason, which is referred to as the alarm'sroot causes. This paper observes that a few dozens of rather persistent root causes generally account for over 90% of the alarms that an intrusion detection system triggers. Therefore, we argue that alarms should be handled by identifying and removing the most predominant and persistent root causes. To make this paradigm practicable, we propose a novel alarm-clustering method that supports the human analyst in identifying root causes. We present experiments with real-world intrusion detection alarms to show how alarm clustering helped us identify root causes. Moreover, we show that the alarm load decreases quite substantially if the identified root causes are eliminated so that they can no longer trigger alarms in the future.
A secure and private system for subscription-based remote services
Authors: Persiano Pino , Visconti Ivan
Published: February 2004

In this paper we study privacy issues regarding the use of the SSL/TLS protocol and X.509 certificates. Our main attention is placed on subscription-based remote services (e.g., subscription to newspapers and databases) where the service manager charges a flat fee for a period of time independent of the actual number of times the service is requested.We start by pointing out that restricting the access to such services by using X.509 certificates and the SSL/TLS protocol, while preserving the interests of the service managers, neglects the right to privacy of the users.We then propose the concept of a
crypto certificate
and the Secure and
Private
Socket Layer protocol (SPSL protocol, in short) and show how they can be used to preserve user privacy and, at the same time, protecting the interests of the service managers. The SPSL protocol only requires the user to have a
standard
X.509 certificate (with an RSA key) and does not require the user to get any special ad hoc certificate.Finally, we show the viability of the proposed solution by describing a system based on SPSL for secure and private access to subscription-based web services. Our implementation includes an SPSL proxy for a TLS-enabled web client and a module for the Apache web server along with administrative tools for the server side. The system has been developed starting from the implementation of an API for the SPSL protocol that we describe in the paper.
Flexible access control policy specification with constraint logic programming
Authors: Barker Steve , Stuckey Peter J.
Published: February 2004

We show how a range of role-based access control (RBAC) models may be usefully represented as constraint logic programs, executable logical specifications. The RBAC models that we define extend the "standard" RBAC models that are described by Sandhu et al., and enable security administrators to define a range of access policies that may include features, like denials of access and temporal authorizations, that are often useful in practice, but which are not widely supported in existing access control models. Representing access policies as constraint logic programs makes it possible to support certain policy options, constraint checks, and administrator queries that cannot be represented by using related methods (like logic programs). Representing an access control policy as a constraint logic program also enables access requests and constraint checks to be efficiently evaluated.
Public-key support for group collaboration
Authors: Ellison Carl , Dohrmann Steve
Published: February 2004

This paper characterizes the security of group collaboration as being a product not merely of cryptographic algorithms and coding practices, but also of the man-machine process of group creation. We show that traditional security mechanisms do not properly address the needs of a secured collaboration and present a research prototype, called NGC (next generation collaboration), that was designed to meet those needs. NGC distinguishes itself in the care with which the man-machine process was analyzed and shaped to improve the security of the whole process. We include a detailed analysis of the problem of binding a name to a key, traditionally thought to be the province of PKI, but we show that the SDSI local name concept produces a result with superior security to that produced by standard PKI.
Greedy facility location algorithms analyzed using dual fitting with factor-revealing LP
Authors: Jain Kamal , Mahdian Mohammad , Markakis Evangelos , Saberi Amin , Vazirani Vijay V.
Published: February 2004

In this article, we will formalize the method of dual fitting and the idea of factor-revealing LP. This combination is used to design and analyze two greedy algorithms for the metric uncapacitated facility location problem. Their approximation factors are 1.861 and 1.61, with running times of
O
(
m
log
m
) and
O
(
n
3
), respectively, where
n
is the total number of vertices and
m
is the number of edges in the underlying complete bipartite graph between cities and facilities. The algorithms are used to improve recent results for several variants of the problem.
Improving table compression with combinatorial optimization
Authors: Buchsbaum Adam L. , Fowler Glenn S. , Giancarlo Raffaele
Published: February 2004

We study the problem of compressing massive tables within the partition-training paradigm introduced by Buchsbaum et al. [2000], in which a table is partitioned by an off-line training procedure into disjoint intervals of columns, each of which is compressed separately by a standard, on-line compressor like gzip. We provide a new theory that unifies previous experimental observations on partitioning and heuristic observations on column permutation, all of which are used to improve compression rates. Based on this theory, we devise the first on-line training algorithms for table compression, which can be applied to individual files, not just continuously operating sources; and also a new, off-line training algorithm, based on a link to the asymmetric traveling salesman problem, which improves on prior work by rearranging columns prior to partitioning. We demonstrate these results experimentally. On various test files, the on-line algorithms provide 35--55% improvement over gzip with negligible slowdown; the off-line reordering provides up to 20% further improvement over partitioning alone. We also show that a variation of the table compression problem is MAX-SNP hard.
Magic Functions
Authors: Dwork Cynthia , Naor Moni , Reingold Omer , Stockmeyer Larry
Published: February 2004

We prove that three apparently unrelated fundamental problems in distributed computing, cryptography, and complexity theory, are essentially the same problem. These three problems and brief descriptions of them follow. (1)
The selective decommitment problem.
An adversary is given commitments to a collection of messages, and the adversary can ask for some subset of the commitments to be opened. The question is whether seeing the decommitments to these open plaintexts allows the adversary to learn something unexpected about the plaintexts that are unopened. (2)
The power of 3-round weak zero-knowledge arguments.
The question is what can be proved in (a possibly weakened form of) zero-knowledge in a 3-round argument. In particular, is there a language outside of BPP that has a 3-round public-coin weak zero-knowledge argument? (3)
The Fiat-Shamir methodology.
This is a method for converting a 3-round public-coin argument (viewed as an identification scheme) to a 1-round signature scheme. The method requires what we call a "magic function" that the signer applies to the first-round message of the argument to obtain a second-round message (queries from the verifier). An open question here is whether every 3-round public-coin argument for a language outside of BPP has a magic function.It follows easily from definitions that if a 3-round public-coin argument system is zero-knowledge in the standard (fairly strong) sense, then it has no magic function. We define a weakening of zero-knowledge such that zero-knowledge ⇒ no-magic-function still holds. For this weakened form of zero-knowledge, we give a partial converse: informally, if a 3-round public-coin argument system is not weakly zero-knowledge, then some form of magic is possible for this argument system. We obtain our definition of weak zero-knowledge by a sequence of weakenings of the standard definition, forming a hierarchy. Intermediate forms of zero-knowledge in this hierarchy are reasonable ones, and they may be useful in applications. Finally, we relate the selective decommitment problem to public-coin proof systems and arguments at an intermediate level of the hierarchy, and obtain several positive security results for selective decommitment.