bluuebunny/crossref_metadata_2025 huggingface dataset:
The complexity of XPath query evaluation and XML typing
Authors: Gottlob Georg , Koch Christoph , Pichler Reinhard , Segoufin Luc
Published: August 2005

We study the complexity of two central XML processing problems. The first is XPath 1.0 query processing, which has been shown to be in PTIME in previous work. We prove that both the data complexity and the query complexity of XPath 1.0 fall into lower (highly parallelizable) complexity classes, while the combined complexity is PTIME-hard. Subsequently, we study the sources of this hardness and identify a large and practically important fragment of XPath 1.0 for which the combined complexity is LOGCFL-complete and, therefore, in the highly parallelizable complexity class NC
2
. The second problem is the complexity of validating XML documents against various typing schemes like Document Type Definitions (DTDs), XML Schema Definitions (XSDs), and tree automata, both with respect to data and to combined complexity. For data complexity, we prove that validation is in LOGSPACE and depends crucially on how XML data is represented. For the combined complexity, we show that the complexity ranges from LOGSPACE to LOGCFL, depending on the typing scheme.
Evaluating implicit measures to improve web search
Authors: Fox Steve , Karnawat Kuldeep , Mydland Mark , Dumais Susan , White Thomas
Published: August 2005

Of growing interest in the area of improving the search experience is the collection of implicit user behavior measures (implicit measures) as indications of user interest and user satisfaction. Rather than having to submit explicit user feedback, which can be costly in time and resources and alter the pattern of use within the search experience, some research has explored the collection of implicit measures as an efficient and useful alternative to collecting explicit measure of interest from users.This research article describes a recent study with two main objectives. The first was to test whether there is an association between explicit ratings of user satisfaction and implicit measures of user interest. The second was to understand what implicit measures were most strongly associated with user satisfaction. The domain of interest was Web search. We developed an instrumented browser to collect a variety of measures of user activity and also to ask for explicit judgments of the relevance of individual pages visited and entire search sessions. The data was collected in a workplace setting to improve the generalizability of the results.Results were analyzed using traditional methods (e.g., Bayesian modeling and decision trees) as well as a new usage behavior pattern analysis (“gene analysis”). We found that there was an association between implicit measures of user activity and the user's explicit satisfaction ratings. The best models for individual pages combined clickthrough, time spent on the search result page, and how a user exited a result or ended a search session (exit type/end action). Behavioral patterns (through the gene analysis) can also be used to predict user satisfaction for search sessions.
Ad Hoc, self-supervising peer-to-peer search networks
Authors: Cooper Brian F. , Garcia-Molina Hector
Published: August 2005

Peer-to-peer search networks are a popular and widely deployed means of searching massively distributed digital information repositories. Unfortunately, as such networks grow, peers may become overloaded processing messages from other peers. This article examines how to reduce the load on nodes in P2P networks by allowing them to self-organize into a relatively efficient network, and then self-tune to make the network even more efficient. Two local operations used by a peer are introduced:
connect()
, in which the peer forms an ad hoc search or index link to another peer, and
break()
, in which the peer breaks a link that is producing too much load. By replacing fixed rules with dynamic local decision-making, such “self-supervising” networks can better adjust to network conditions. Different ways to implement
connect()
and
break()
are described, and the network structures that form under different configurations are examined. Simulation results indicate that the ad hoc networks formed using the described techniques are more efficient than popular supernode topologies for several important scenarios. Results for the fault tolerance and search latency of such ad hoc networks are also presented.
Communication in computer science classrooms: understanding defensive climates as a means of creating supportive behaviors
Authors: Garvin-Doxas Kathy , Barker Lecia J.
Published: August 2005

All learning environments are characterized by numerous communication and interaction practices, which lend themselves to an overall characterization of the climate as defensive or supportive. A case study of public communication and interaction in a large, research-intensive university's first year computer science courses illustrates a learning environment primarily characterized by elements and behaviors associated with a defensive communication climate. Descriptions of classroom interactions and behaviors illustrate what a defensive communication climate “looks like” in terms of behavior, based on extensive observational research. Interview data demonstrates that defensive communication practices can lead to attrition among women in the major and illustrates ways in which the communication climate that characterizes the major is experienced and interpreted by women in the courses. This data also links defensive communication behaviors with lower confidence among women toward their major --- results consistent with previous studies of the causes of attrition among women in other Science, Technology, Engineering, and Mathematics (STEM) disciplines. Classroom experiences and behaviors that reflect a more supportive communication climate will be discussed within the context of practices and interactions that professors can engage in to ensure that their courses lean toward a supportive rather than a defensive environment as a way of making computer science learning environments more inclusive.
Pair-programming helps female computer science students
Authors: Werner Linda L. , Hanks Brian , McDowell Charlie
Published: August 2005

Pair-programming has been found to be very beneficial in educational settings. Students who pair in their introductory programming course are more confident, have greater course completion and pass rates, and are more likely to persist in computer-related majors. Although pairing helps all students, we believe that it is particularly beneficial for women because it addresses several significant factors that limit women's participation in computer science. We provide reasons for our belief that pair-programming helps women persist in these majors. We also repeat, with special emphasis on the impact on women, some details published elsewhere regarding our experiments on pair-programming with college and university students. Additionally, we provide new data that supports our original findings.
The robots are coming
Authors: Holmquist Lars Erik
Published: August 2005

On the Edge
will place the spotlight on exciting, unusual and often controversial developments from the world of interaction design. It will discuss issues that challenge the current norm---whether in industry or academia---in a way that is not possible in either a shallow news article or a formal research paper. Topics can include a cool gadget that's just been launched in Tokyo's Akihabara district, or some far out research prototype presented at the latest SIGGRAPH or UbiComp conference. I will also introduce concepts and methods that put a new perspective on the profession. Prototypes are cool, but unless they come with a well-grounded theory and a connection to the world outside the lab, they will soon be forgotten and left in a pile together with last year's Tamagotchis and CHI papers. How can interaction designers---who already maintain a precarious balancing act on the borderline between art and science---create products and interfaces that have the potential to change peoples' lives, while simultaneously serving all their masters: commerce and culture, research and intuition, engineering and design, and so on? Welcome to life
On The Edge.
Challenges of migrating to agile methodologies
Authors: Nerur Sridhar , Mahapatra RadhaKanta , Mangalaraj George
Published: August 2005

Software development methodologies are constantly evolving due to changing technologies and new demands from users. Today's dynamic business environment has given rise to emergent organizations that continuously adapt their structures, strategies, and policies to suit the new environment [12]. Such organizations need information systems that constantly evolve to meet their changing requirements---but the traditional, plan-driven software development methodologies lack the flexibility to dynamically adjust the development process.
Scale-free geometry in OO programs
Authors: Potanin Alex , Noble James , Frean Marcus , Biddle Robert
Published: August 2005

Though conventional OO design suggests programs should be built from many small objects, like Lego bricks, they are instead built from objects that are scale-free, like fractals, and unlike Lego bricks.
How to prepare tomorrow's technologists for global networks of innovation
Authors: Nambisan Satish
Published: August 2005

University curricula must prepare them to be able to recognize and embrace technologies, components, markets, and customers wherever in the world they happen to be.
Introduction
Authors: Desai Anand
Published: August 2005

It is common knowledge that individuals, the communities in which we live, and the organizations we create adapt over time and changing conditions. It is also generally understood that organizations, communities, and individuals are all complex entities. To state that organizations are adaptive complex enterprises (ACE) is neither novel nor new: What is new, however, is that we now have a language and a set of constructs that allow us to formally conceptualize and discuss these concepts. (See the sidebar for a brief discussion of the terms adaptive complex enterprises and complex adaptive systems.)
Fractal architecture for the adaptive complex enterprise
Authors: Ramanathan Jay
Published: August 2005

Today's businesses must continuously adapt to external conditions in accelerated time frames. This requires businesses to shift from strategies that eliminate variation to those that embrace variation and changing conditions. Industrial-age Make-Sell businesses accomplished objectives by steadily eliminating variation. In contrast, today's sense-and-respond (S-R) businesses must often execute by embracing variation and learn to perform given widely varying circumstances [4]. Specifically, the S-R business must adapt to external conditions by managing along the chain: "Sense changing opportunities→Request variation→Product variation→Response process variation→Resource variation and Information variation→Efficient delivery and feedback→Business growth and survival." (Here, the implication symbol "→" reflects cause and effect.) Recognizing that IT holds the promise of enabling the S-R enterprise, transformation is often accompanied by enterprise integration projects but with limited success. Project experiences spanning the past 10 years suggest that IT must first meet key challenges.
Quadric-based simplification in any dimension
Authors: Garland Michael , Zhou Yuan
Published: August 2005

We present a novel generalization of the quadric error metric used in surface simplification that can be used for simplifying simplicial complexes of any type embedded in Euclidean spaces of any dimension. We demonstrate that our generalized simplification system can produce high quality approximations of plane and space curves, triangulated surfaces, tetrahedralized volume data, and simplicial complexes of mixed type. Our method is both efficient and easy to implement. It is capable of processing complexes of arbitrary topology, including nonmanifolds, and can preserve intricate boundaries.
Image-based spatio-temporal modeling and view interpolation of dynamic events
Authors: Vedula Sundar , Baker Simon , Kanade Takeo
Published: August 2005

We present an approach for modeling and rendering a dynamic, real-world event from an arbitrary viewpoint, and at any time, using images captured from multiple video cameras. The event is modeled as a nonrigidly varying dynamic scene, captured by many images from different viewpoints, at discrete times. First, the spatio-temporal geometric properties (shape and instantaneous motion) are computed. The view synthesis problem is then solved using a reverse mapping algorithm, ray-casting across space and time, to compute a novel image from any viewpoint in the 4D space of position and time. Results are shown on real-world events captured in the CMU 3D Room, by creating synthetic renderings of the event from novel, arbitrary positions in space and time. Multiple such recreated renderings can be put together to create retimed fly-by movies of the event, with the resulting visual experience richer than that of a regular video clip, or switching between images from multiple cameras.
Mood swings: expressive speech animation
Authors: Chuang Erika , Bregler Christoph
Published: August 2005

Motion capture-based facial animation has recently gained popularity in many applications, such as movies, video games, and human-computer interface designs. With the use of sophisticated facial motions from a human performer, animated characters are far more lively and convincing. However, editing motion data is difficult, limiting the potential of reusing the motion data for different tasks. To address this problem, statistical techniques have been applied to learn models of the facial motion in order to derive new motions based on the existing data. Most existing research focuses on audio-to-visual mapping and reordering of words, or on photo-realistically matching the synthesized face to the original performer. Little attention has been paid to modifying and controlling facial expression, or to mapping expressive motion onto other 3D characters.This article describes a method for creating expressive facial animation by extracting information from the expression axis of a speech performance. First, a statistical model for factoring the expression and visual speech is learned from video. This model can be used to analyze the facial expression of a new performance or modify the facial expressions of an existing performance. With the addition of this analysis of the facial expression, the facial motion can be more effectively retargeted to another 3D face model. The blendshape retargeting technique is extended to include subsets of morph targets that belong to different facial expression groups. The proportion of each subset included in a final animation is weighted according to the expression information. The resulting animation conveys much more emotion than if only the motion vectors were used for retargeting. Finally, since head motion is very important in adding liveness to facial animation, we introduces an audio-driven synthesis technique for generating new head motion.
Supporting application development in the semantic web
Authors: Oberle Daniel , Staab Steffen , Studer Rudi , Volz Raphael
Published: August 2005

The Semantic Web augments the current WWW by giving information a well-defined meaning, better enabling computers and people to work in cooperation. This is done by adding machine understandable content to Web resources. Such added content is called metadata, whose semantics is provided by referring to an ontology---a domain's conceptualization agreed upon by a community. The Semantic Web relies on the complex interaction of several technologies involving ontologies. Therefore, sophisticated Semantic Web applications typically comprise more than one software module. Instead of coming up with proprietary solutions, developers should be able to rely on a generic infrastructure for application development in this context. We call such an infrastructure Application Server for the Semantic Web whose design and development are based on existing Application Servers. However, we apply and augment their underlying concepts for use in the Semantic Web and integrate semantic technology within the server itself. The article discusses requirements and design issues of such a server, presents our implementation KAON SERVER and demonstrates its usefulness by a detailed scenario.
Criminal network analysis and visualization
Authors: Xu Jennifer , Chen Hsinchun
Published: August 2005

A new generation of data mining tools and applications work to unearth hidden patterns in large volumes of crime data.
The CAN-SPAM Act
Authors: Lee Younghwa
Published: August 2005

Several recommendations for improving the effectiveness of anti-spam legislation are presented.
Resource aware programming
Authors: Moreau Luc , Queinnec Christian
Published: August 2005

We introduce the
Resource Aware Programming
framework, which allows users to monitor the resources used by their programs and to programmatically express policies for the management of such resources. The framework is based on a notion of hierarchical groups, which act as resource containers for the computations they sponsor. Asynchronous notifications for resource exhaustion and for computation termination can be handled by arbitrary user code, which is also executed under the control of this hierarchical group structure. Resources are manipulated by the programmer using resource descriptors, whose operations are specified by a resource algebra. In this article, we overview the Resource Aware Programming framework and describe its semantics in the form of a language-independent abstract machine able to model both shared and distributed memory environments. Finally, we discuss a prototype implementation of the Resource Aware Programming framework in Java.
Correction of errors in a verb modality corpus for machine translation with a machine-learning method
Authors: Murata Masaki , Utiyama Masao , Uchimoto Kiyotaka , Isahara Hitoshi , Ma Qing
Published: August 2005

In recent years, various types of tagged corpora have been constructed and much research using tagged corpora has been done. However, tagged corpora contain errors, which impedes the progress of research. Therefore, the correction of errors in corpora is an important research issue. In this study we investigate the correction of such errors, which we call
corpus correction.
Using machine-learning methods, we applied corpus correction to a verb modality corpus for machine translation. We used the maximum-entropy and decision-list methods as machine-learning methods. We compared several kinds of methods for corpus correction in our experiments, and determined which is most effective by using a statistical test. We obtained several noteworthy findings: (1) Precision was almost the same for both detection and correction, so it is more convenient to do both correction and detection, rather than detection only. (2) In general, the maximum-entropy method worked better than the decision-list method; but the two methods had almost the same precision for the top 50 pieces of extracted data when closed data was used. (3) In terms of precision, the use of closed data was better than the use of open data; however, in terms of the total number of extracted errors, the use of open data was better than the use of closed data. Based on our analysis of these results, we developed a good method for corpus correction. We confirmed the effectiveness of our method by carrying out experiments on machine translation. As corpus-based machine translation continues to be developed, the corpus correction we discuss in this article should prove to be increasingly significant.
Simplify: a theorem prover for program checking
Authors: Detlefs David , Nelson Greg , Saxe James B.
Published: August 2005

This article provides a detailed description of the automatic theorem prover Simplify, which is the proof engine of the Extended Static Checkers ESC/Java and ESC/Modula-3. Simplify uses the Nelson--Oppen method to combine decision procedures for several important theories, and also employs a matcher to reason about quantifiers. Instead of conventional matching in a term DAG, Simplify matches up to equivalence in an E-graph, which detects many relevant pattern instances that would be missed by the conventional approach. The article describes two techniques, error context reporting and error localization, for helping the user to determine the reason that a false conjecture is false. The article includes detailed performance figures on conjectures derived from realistic program-checking problems.
Making by making strange
Authors: Bell Genevieve , Blythe Mark , Sengers Phoebe
Published: August 2005

This article argues that because the home is so familiar, it is necessary to make it strange, or defamiliarize it, in order to open its design space. Critical approaches to technology design are of both practical and social importance in the home. Home appliances are loaded with cultural associations such as the gendered division of domestic labor that are easy to overlook. Further, homes are not the same everywhere---even within a country. Peoples' aspirations and desires differ greatly across and between cultures. The target of western domestic technology design is often not the user, but the consumer. Web refrigerators that create shopping lists, garbage cans that let advertisers know what is thrown away, cabinets that monitor their contents and order more when supplies are low are central to current images of the wireless, digital home of the future. Drawing from our research in the United States, the United Kingdom, and Asia, we provide three different narratives of defamiliarization. A historical reading of American kitchens provides a lens with which to scrutinize new technologies of domesticity, an ethnographic account of an extended social unit in England problematizes taken-for-granted domestic technologies, and a comparative ethnography of the role of information and communication technologies in the daily lives of urban Asia's middle classes reveals the ways in which new technologies can be captured and domesticated in unexpected ways. In the final section of the article, we build on these moments of defamiliarization to suggest a broad set of challenges and strategies for design in the home.
A multilevel analysis of sociability, usability, and community dynamics in an online health community
Authors: Maloney-Krichmar Diane , Preece Jenny
Published: August 2005

The aim of this research is to develop an in-depth understanding of the dynamics of online group interaction and the relationship between the participation in an online community and an individual's off-line life. The 2½-year study of a thriving online health support community (Bob's ACL WWWBoard) used a broad fieldwork approach, guided by the ethnographic research techniques of observation, interviewing, and archival research in combination with analysis of the group's dynamics during a one-week period. Research tools from the social sciences were used to develop a thick, rich description of the group. The significant findings of this study include: dependable and reliable technology is more important than state-of-the-art technology in this community; strong community development exists despite little differentiation of the community space provided by the software; members reported that participation in the community positively influenced their offline lives; strong group norms of support and reciprocity made externally-driven governance unnecessary; tools used to assess group dynamics in face-to-face groups provide meaningful information about online group dynamics; and, membership patterns in the community and strong subgroups actively contributed to the community's stability and vitality.
Socio-technical environments supporting people with cognitive disabilities using public transportation
Authors: Carmien Stefan , Dawe Melissa , Fischer Gerhard , Gorman Andrew , Kintsch Anja , Sullivan James F.
Published: August 2005

Public transportation systems are among the most ubiquitous and complex large-scale systems found in modern society. For those unable to drive such as people with cognitive disabilities, these systems are essential gateways for participation in community activities, socialization, and independence. To understand the magnitude and scope of this national problem, we highlight deficiencies identified in an international study by the Transportation Research Board of the National Research Council and present specific cognitive barriers identified in empirical studies of transportation systems in several U.S. cities.An interdisciplinary team of HCI researchers, urban transportation planners, commercial technologists, and assistive care specialists are now collaborating on the Mobility-for-All project to create architectures and prototypes that support those with cognitive disabilities and their caregivers. We have grounded our research and design efforts using a
distributed cognition
framework. We have derived requirements for our designs by analyzing “how things are” for individuals with cognitive disabilities who learn and use public transportation systems. We present a socio-technical architecture that has three components: a) a personal travel assistant that uses real-time Global Positioning Systems data from the bus fleet to deliver just-in-time prompts; b) a mobile prompting client and a prompting script configuration tool for caregivers; and c) a monitoring system that collects real-time task status from the mobile client and alerts the support community of potential problems. We then describe a phased community-centered assessment approach that begins at the design stage and continues to be integrated throughout the project.This research has broad implications for designing more human-centered transportation systems that are universally accessible for other disenfranchised communities such as the elderly or nonnative speaker. This project presents an “in-the-world” research opportunity that challenges our understanding about mobile human computer interactions with ubiquitous, context-aware computing architectures in noisy, uncontrolled environments; personalization and user modeling techniques; and the design of universally accessible interfaces for complex systems through participatory design processes.This article provides both a near-term vision and an architecture for transportation systems that are socially inclusive, technologically appealing, and easier for everyone to use.
Immersive authoring
Authors: Lee Gun A. , Kim Gerard J. , Billinghurst Mark
Published: August 2005

Users experience and verify immersive content firsthand while creating it within the same virtual environment.
Applying user-centered design to mobile application development
Authors: Kangas Eeva , Kinnunen Timo
Published: August 2005

Digia was among the first companies to develop third-party software applications that can be installed in Symbian smart phones by service providers or end users [3]. In 2001, Digia was searching for new product ideas for the nascent smart phone market. At the same time, the User Experience (UE) Group was established in the company and we began to work together with software engineers to transform product ideas into final products. The first product we worked on was the navigation software for Nokia Communicators known as Genimap Navigator, which utilized a Global Positioning System connection and a map database on a network server.
Sequent and hypersequent calculi for abelian and łukasiewicz logics
Authors: Metcalfe George , Olivetti Nicola , Gabbay Dov
Published: August 2005

We present two embeddings of Łukasiewicz logicŁinto Meyer and Slaney's Abelian logicA, the logic of lattice-ordered Abelian groups. We give new analytic proof systems forAand use the embeddings to derive corresponding systems forŁ. These include hypersequent calculi, terminating hypersequent calculi, co-NP labeled sequent calculi, and unlabeled sequent calculi.
Efficient algorithms for processing XPath queries
Authors: Gottlob Georg , Koch Christoph , Pichler Reinhard
Published: August 2005

Our experimental analysis of several popular XPath processors reveals a striking fact: Query evaluation in each of the systems requires time exponential in the size of queries in the worst case. We show that XPath can be processed much more efficiently, and propose main-memory algorithms for this problem with polynomial-time combined query evaluation complexity. Moreover, we show how the main ideas of our algorithm can be profitably integrated into existing XPath processors. Finally, we present two fragments of XPath for which linear-time query processing algorithms exist and another fragment with linear-space/quadratic-time query processing.
Making snapshot isolation serializable
Authors: Fekete Alan , Liarokapis Dimitrios , O'Neil Elizabeth , O'Neil Patrick , Shasha Dennis
Published: August 2005

Snapshot Isolation (SI) is a multiversion concurrency control algorithm, first described in Berenson et al. [1995]. SI is attractive because it provides an isolation level that avoids many of the common concurrency anomalies, and has been implemented by Oracle and Microsoft SQL Server (with certain minor variations). SI does not guarantee serializability in all cases, but the TPC-C benchmark application [TPC-C], for example, executes under SI without serialization anomalies. All major database system products are delivered with default nonserializable isolation levels, often ones that encounter serialization anomalies more commonly than SI, and we suspect that numerous isolation errors occur each day at many large sites because of this, leading to corrupt data sometimes noted in data warehouse applications. The classical justification for lower isolation levels is that applications can be run under such levels to improve efficiency when they can be shown not to result in serious errors, but little or no guidance has been offered to application programmers and DBAs by vendors as to how to avoid such errors. This article develops a theory that characterizes when nonserializable executions of applications can occur under SI. Near the end of the article, we apply this theory to demonstrate that the TPC-C benchmark application has no serialization anomalies under SI, and then discuss how this demonstration can be generalized to other applications. We also present a discussion on how to modify the program logic of applications that are nonserializable under SI so that serializability will be guaranteed.
Aggregate nearest neighbor queries in spatial databases
Authors: Papadias Dimitris , Tao Yufei , Mouratidis Kyriakos , Hui Chun Kit
Published: August 2005

Given two spatial datasets
P
(e.g., facilities) and
Q
(queries), an
aggregate nearest neighbor
(ANN) query retrieves the point(s) of
P
with the smallest aggregate distance(s) to points in
Q
. Assuming, for example,
n
users at locations
q
1
,…
q

n

, an ANN query outputs the facility
p
∈
P
that minimizes the
sum
of distances |
pq
i
| for 1 ≤
i
≤
n
that the users have to travel in order to meet there. Similarly, another ANN query may report the point
p
∈
P
that minimizes the
maximum
distance that any user has to travel, or the
minimum
distance from some user to his/her closest facility. If
Q
fits in memory and
P
is indexed by an R-tree, we develop algorithms for aggregate nearest neighbors that capture several versions of the problem, including weighted queries and incremental reporting of results. Then, we analyze their performance and propose cost models for query optimization. Finally, we extend our techniques for disk-resident queries and approximate ANN retrieval. The efficiency of the algorithms and the accuracy of the cost models are evaluated through extensive experiments with real and synthetic datasets.
XSQ
Authors: Peng Feng , Chawathe Sudarshan S.
Published: August 2005

We have implemented and released the XSQ system for evaluating XPath queries on streaming XML data. XSQ supports XPath features such as multiple predicates, closures, and aggregation, which pose interesting challenges for streaming evaluation. Our implementation is based on using a hierarchical arrangement of augmented finite state automata. A design goal of XSQ is buffering data for the least amount of time possible. We present a detailed experimental study that characterizes the performance of XSQ and related systems, and that illustrates the performance implications of XPath features such as closures.
An interdisciplinary field robotics program for undergraduate computer science and engineering education
Authors: Kitts Christopher , Quinn Neil
Published: August 2005

Santa Clara University's Robotic Systems Laboratory conducts an aggressive robotic development and operations program in which interdisciplinary teams of undergraduate students build and deploy a wide range of robotic systems, ranging from underwater vehicles to spacecraft. These year-long projects expose students to the breadth of and interdependence among engineering disciplines, the span of processes in a system development lifecycle, and the challenges of managing a development process. Over the past five years, this program has provided more than 150 students with exposure to computer science and engineering topics, including software engineering, algorithm development, human-computer interface design, and artificial intelligence. This program provides exciting and compelling educational opportunities for students, offers real-world applications that naturally motivate the need for specific computing technologies, and serves a broader research and development program that utilizes the functional robotic systems to support externally-funded science and technology demonstration missions. The experience of the authors, as well as formal program assessment data, show that this program provides strong student motivation for learning, offers comprehensive and valuable educational experiences, and enhances student performance. This article reviews the Santa Clara robotics program, highlights the role of computer science and engineering in several projects, and presents the assessment data showing the positive results of this program.
Using RoboCup in university-level computer science education
Authors: Sklar Elizabeth , Parsons Simon , Stone Peter
Published: August 2005

In the education literature, team-based projects have proven to be an effective pedagogical methodology. We have been using
RoboCup
challenges as the basis for class projects in undergraduate and masters level courses. This article discusses several independent efforts in this direction and presents our work in the development of shared resources and evaluation instruments. We outline three courses and describe related class projects in order to make the context of our investigation clear and make it possible for others to replicate and extend our work as well as contribute to the shared resource.
CONCEPTS AND APPLICATIONS OF TRAP CROPPING IN PEST MANAGEMENT
Authors: Shelton A.M. , Badenes-Perez F.R.
Published: August 2005

▪ Abstract  Interest in trap cropping, a traditional tool of pest management, has increased considerably in recent years. In this review we propose a broader definition of trap cropping that encompasses the inherent characteristics of the trap crop plants themselves as well as the strategies associated with their deployment. Inherent characteristics of a trap crop may include not only natural differential attractiveness for oviposition and feeding, but also other attributes that enable the trap crop plants to serve as a sink for insects or the pathogens they vector. Successful deployment of trap crops within a landscape depends on the inherent characteristics of the trap crop and the higher value crop, the spatial and temporal characteristics of each, the behavior and movement patterns of insect pests, and the agronomic and economic requirements of the production system. Thus, trap cropping is more knowledge-intensive than many other forms of pest management. We review recent references on trap cropping, classify them according to their modalities and level of implementation, and provide a synthesis of the factors that influence the success of trap cropping. Last, we provide a list of recommendations and guidelines that should prove helpful in moving trap cropping forward to its full potential.
Ischemia-induced cleavage of cadherins in NRK cells requires MT1-MMP (MMP-14)
Authors: Covington Marisa D. , Burghardt Robert C. , Parrish Alan R.
Published: August 2005

Ischemia is a leading cause of acute renal failure (ARF), a disease associated with high morbidity and mortality. Disruption of intercellular adhesion in the proximal tubules is linked to ARF, although the molecular mechanism(s) remains unclear. Our previous studies showed that ischemia is associated with cadherin cleavage and loss in NRK cells, putatively due to a matrix metalloproteinase (MMP) ( 7 ). In the current studies, a MMP required for E-cadherin cleavage and N-cadherin loss was identified. Chemical inhibitors against a number of soluble MMPs ( 1 , 2 , 3 , 8 , 9 ) failed to completely attenuate ischemia-induced cadherin loss. Under ischemic conditions, there was an increase in active membrane-type (MT)1-MMP but a decrease in MMP-2 protein expression. Plating cells on fibronectin protected against ischemia-induced loss of cadherins and, interestingly, no increase in active MT1-MMP levels was seen in ischemic cells on fibronectin-coated dishes. In addition, L cells stably expressing E- (LE) or N-cadherin (LN), but lacking MT1-MMP expression, were resistant to ischemia-induced cadherin loss. The role of MT1-MMP in ischemia-induced cadherin loss was confirmed by either blocking MT1-MMP activity with a neutralizing antibody or expression with shRNA constructs which protected full-length E- and N-cadherin during ischemia. Using shRNA constructs to suppress MT1-MMP expression, ischemia-induced disruption of cadherin function was ablated, and cell-cell contacts were preserved. These results demonstrate that ischemia induces increased expression of active MT1-MMP and subsequent disruption of cadherin/catenin complexes, implying that MT1-MMP plays a role in ischemia-induced ARF.
Psychophysics of Electrical Stimulation of Striate Cortex in Macaques
Authors: Bartlett John R. , DeYoe Edgar A. , Doty Robert W. , Lee Barry B. , Lewine Jeffrey D. , Negrão Nubio , Overman William H.
Published: August 2005

Macaques indicated their detection of onset or alteration of 0.2-ms pulses applied in various configurations through electrodes implanted in striate cortex. When microelectrodes were introduced and left in place, the threshold for detection of 100-Hz pulses nearly doubled within 24 h. However, for chronically implanted platinum-alloy macroelectrodes detection thresholds usually remained stable for many months, independently of location within striate cortex or its immediately subjacent white matter. Thresholds were unaffected by the visual conditions, such as light versus darkness, or movement of the eyes; but in one animal blind after acute glaucoma thresholds for loci in striate cortex were permanently decreased by about 50%. Learning to respond to electrical stimulation of the optic tract produced no tendency to respond to such stimulation of striate cortex. Onset of stimulation at a given locus could be detected even in the face of continuous supraliminal stimulation at four surrounding loci on a 3-mm radius. The surround stimulation did alter the threshold of the central locus, but such stimuli could not summate if they were subliminal by some 10%. Cessation of stimulation that had been continuing for 1 min to 1 h could be detected if it were being applied at a level 20–75% above that needed for detection of stimulus onset. Continuous stimulation had a pronounced “priming” effect, in that modulation of frequency or intensity of such stimulation by as little as 5% could be detected (e.g., 20 μA in a background of 500 μA, or <2-ms interpulse interval with pulses at 50 Hz). Using pulses inserted in various phase relations to ongoing pulses at 2–5 Hz, it could be determined that stimulus pulses were surrounded by a strong facilitatory period for about 30 ms, which was then replaced by refractoriness. Given the congruence of macaque and human visual anatomy and psychophysics, these results further encourage efforts to develop a cortical prosthesis for the blind.
Trust Diffusion: The Effect of Interpersonal Trust on Structure, Function, and Organizational Transparency
Authors: Williams Cynthia Clark
Published: August 2005

This study presents an organizational model to explain when and how trust permeates an organization, when it is constrained and to what extent it informs the perceptions of transparency among stakeholders. Through the use of qualitative research, resulting in five corporate case studies, and a separate quantitative analysis, it was possible to demonstrate ways in which trust can be diffused amongorganizational layers. These findings add to the literature by analyzing trust in organizational settings via reciprocal dyadic relationships in a social-structural context. These findings suggest that functional elements and informal network position contributed to the dyad's ability to establish positive trust climates and specific communication and cooperative behaviors were critical in diffusing trust to the group level; the degree of organizational transparency positively correlated to the degree of dyadic and group-level trust.
Calibration of Polytomous Item Families Using Bayesian Hierarchical Modeling
Authors: Johnson Matthew S. , Sinharay Sandip
Published: August 2005

For complex educational assessments, there is an increasing use of item families, which are groups of related items. Calibration or scoring in an assessment involving item families requires models that can take into account the dependence structure inherent among the items that belong to the same item family. This article extends earlier works in three directions: (a) extends the model to take into account item families with polytomous items and implements a Markov chain Monte Carlo algorithm for the estimation of the model parameters, (b) generalizes family response functions to polytomous item families and defines the family score function as ways to examine each family graphically, and (c) uses Bayes factors to select either the more complicated model or a simple model. All three extensions of the earlier works on item families are demonstrated using two data sets: one simulated and one from the National Assessment of Educational Progress.
A new rate index for environmental monitoring of combined reuse/recycle packaging systems
Authors: Tsiliyannis Christos A.
Published: August 2005

It is shown that the conventional recycling rate fails to reflect environmental performance for packaging flows with both recycle and reuse. The reuse rate, the total number of reuse trips and the reuse-lifetime are also shown to be inadequate. A new rate index defined in terms of the total amount of packaging material reaching the consumer is proposed. It reflects immediate improvements in environmental impact according to specific criteria and it reduces to the conventional rate for systems with only recycle. Albeit this shortcut environmental assessment is not entirely comprehensive and does not unveil a full sustainability profile, it may be useful for immediate packaging flow evaluation and policy implementation. For given packaging production technology it reveals a specific maximum level on recycling, below which environmental impacts from processing are limited or reduced, even if production level grows. Cleaner technologies in reprocessing of recycled materials may elevate this maximum level while still limiting or reducing environmental impacts.
Preferential flow in municipal solid waste and implications for long-term leachate quality: valuation of laboratory-scale experiments
Authors: Rosqvist N. H. , Dollar L. H. , Fourie A. B.
Published: August 2005

In this paper, we study and quantify pollutant concentrations after long-term leaching at relatively low flow rates and residual concentrations after heavy flushing of a 0.14 m3 municipal solid waste sample. Moreover, water flow and solute transport through preferential flow paths are studied by model interpretation of experimental break-through curves (BTCs), generated by tracer tests. In the study it was found that high concentrations of chloride remain after several pore volumes of water have percolated through the waste sample. The residual concentration was found to be considerably higher than can be predicted by degradation models. For model interpretations of the experimental BTCs, two probabilistic model approaches were applied, the transfer function model and the Lagrangian transport formulation. The experimental BTCs indicated the presence of preferential flow through the waste mass and the model interpretation of the BTCs suggested that between 19 and 41% of the total water content participated in the transport of solute through preferential flow paths. In the study, the occurrence of preferential flow was found to be dependent on the flow rate in the sense that a high flow rate enhances the preferential flow. However, to fully quantify the possible dependence between flow rate and preferential flow, experiments on a broader range of experimental conditions are suggested. The chloride washout curve obtained over the 4-year study period shows that as a consequence of the water flow in favoured flow paths, bypassing other parts of the solid waste body, the leachate quality may reflect only the flow paths and their surroundings. The results in this study thus show that in order to improve long-term prediction of the leachate quality and quantity the magnitude of the preferential water flow through a landfill must be taken into account.
How to Trick Mother Nature into Letting You Fly Around or Stay Up All Night
Authors: Revell Victoria L. , Eastman Charmane I.
Published: August 2005

Night shift work and rapid transmeridian travel result in a misalignment between circadian rhythms and the new times for sleep, wake, and work, which has health and safety implications for both the individual involved and the general public. Entrainment to the new sleep/wake schedule requires circadian rhythms to be phase-shifted, but this is often slow or impeded. The authors show superimposed light and melatonin PRCs to explain how to appropriately time these zeitgebers to promote circadian adaptation. They review studies in which bright light and melatonin were administered to try to counteract jet lag or to produce circadian adaptation to night work. They demonstrate how jet lag could be prevented entirely if rhythms are shifted before the flight using their preflight plan and discuss the combination of interventions that they now recommend for night shift workers.
Aging Human Circadian Rhythms: Conventional Wisdom May Not Always Be Right
Authors: Monk Timothy H.
Published: August 2005

This review discusses the ways in which the circadian rhythms of older people are different from those of younger adults. After a brief discussion of clinical issues, the review describes the conventional wisdom regarding agerelated changes in circadian rhythms. These can be summarized as four assertions regarding what happens to people as they get older: 1) the amplitude of their circadian rhythms reduces, 2) the phase of their circadian rhythms becomes earlier, 3) their natural free-running period (tau) shortens, and 4) their ability to tolerate abrupt phase shifts (e.g., from jet travel or night work) worsens. The review then discusses the empirical evidence for and against these assertions and discusses some alternative explanations. The conclusions are that although older people undoubtedly have earlier circadian phases than younger adults, and have more trouble coping with shift work and jet lag, evidence for the assertions about rhythm amplitude and tau are, at best, mixed.