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Abstract: This article introduces audio-enhanced paper photos enabled by digital pen technology as an interaction paradigm for supporting and understanding emotional wellbeing in late adulthood, particularly in the context of communication therapy activities and related social interactions. We describe the development of a multimodal pen-based system that enables creation of audio-enhanced paper photos and the application of this technology to two domains: older adults with aphasia working to regain expressive and receptive language after a stroke, and older adults wanting to interact with a family member of advanced age with memory loss. Our pen-based authoring software enables caregivers, both therapists and family members, to create audio-enhanced paper photos to encourage meaningful and emotionally appropriate interaction with the older adults they support. We examine the ways in which emotional information is embedded in audio-enhanced photos and how this approach addresses various aspects of emotional wellbeing in late adulthood. [Copyright &y& Elsevier]

In this paper, the second in a series, the authors have extended and implemented their computational algorithms for improving the scalability of CSD (Computational Structural Dynamics) and FSI (Fluid-Structure Interaction) simulations on emerging architectures like multicore High Performance Computing (HPC) platforms. These algorithmic developments and extensions are classified into two categories: (i) enhanced scalability for CSD simulations on multicore platforms, (ii) newer ideas for running FSI simulations. In the first category, the authors employed the ideas developed in the first paper of this series including the multilevel partitioning strategy, next generation optimized communication procedure and better memory management to get enhanced scalability for CSD simulations. In the second category, the authors came up with a novel solver specific multicore-FSI optimal partitioning so as to improve the overall FSI scalability. After implementing the new "intelligent partitioning" algorithm, a speedup ratio of nearly 2.5x was obtained for the total time. The intelligent partitioning algorithm optimizes the number of solid domains relative to the number of fluid domains to optimize the overall FSI solution, irrespective of the type of the flow solver. In general, the authors have demonstrated (i) good, almost linear scalability for aeroelastic applications with several millions of cells on multicore platforms with thousands of cores, (ii) significant improvement in the scalability for smaller FSI problems using the intelligent partitioning. [ABSTRACT FROM AUTHOR]

Modern waste management provision seeks to meet challenging objectives and strategies while reflecting community aspirations and ensuring cost-effective compliance with statutory obligations. Its social acceptability, which affects both what systems (infrastructure) can be put in place and to what extent their implementation will be successful, is a multi-dimensional phenomenon, often not well understood. In light of the growing evidence that decisions to build new infrastructure are often contested by the public, there is a clear need to understand the role of scientific evidence in public perception, particularly as environmental infrastructure delivery is often objected to by the public on environmental grounds. In this paper the need for waste management infrastructure is reviewed, and the way its delivery in the UK has evolved is used as an example of the role of public perception in the planning and delivery of waste facilities. Findings demonstrate the vital role of public communication in waste management infrastructure delivery. Public perception must be taken into account early in the decision making process, with the public informed and engaged from the start. There is a pressing need for people not simply to accept but to understand and appreciate the need for infrastructure, the nature of infrastructure investments and development, the costs and the benefits involved, and the technological aspects. Scientific evidence and literacy have a critical role to play, facilitating public engagement in a process that empowers people, allowing them to define and handle challenges and influence decisions that will impact their lives. Problem ownership, and an increased probability of any solutions proposed being selected and implemented successfully are potential benefits of such approach. [ABSTRACT FROM AUTHOR]

An optimal convergence condition for Newton iteration is presented which is at least as weak as the one obtained by Traub and Woźniakowski leading also to an at least as precise complexity. The novelty of the paper is the introduction of a restricted convergence domain. That is we find a more precise location where the Newton iterates lie than in earlier studies. Consequently the Lipschitz constants are at least as small as the ones used before. This way and under the same computational cost, we extend the local convergence as well as the complexity of Newton iteration. Numerical examples further justify the theoretical results. [ABSTRACT FROM AUTHOR]

Abstract: Non-speaking people who use Augmentative and Alternative Communication (AAC) systems typically have low rates of communication which reduces their ability to interact with others. Research and development continues in the quest to improve the effectiveness of AAC systems in terms of communication rate and impact. One strategy involves making the basic unit of communication an entire utterance, and designing the AAC system to make the storage, retrieval and production of utterances as easy and efficient as possible. Some approaches take this further and include texts, narratives and/or multimedia material for use in conversation. AAC systems operating in such a manner require a structure for containing and managing conversational material and supporting the production of output during conversation. Ideally such a structure should be modelled on the way actual conversations proceed. A number of partial models for this have been presented thus far. These are reviewed in the paper and an integrated model is then proposed that includes both the structure of a conversation and the way in which an AAC system might produce conversational output (e.g. utterances, texts, multimedia items or combinations of these). Modelling the process in this way gives a structure with which an AAC system can organize the support and guidance that it offers to the person using the system. The paper concludes with consideration of three areas of development for further investigation. [Copyright &y& Elsevier]

Abstract: This paper outlines the first Asian network-based speech-to-speech translation system developed by the Asian Speech Translation Advanced Research (A-STAR) consortium. Eight research groups comprising the A-STAR members participated in the experiments, covering nine languages, i.e., eight Asian languages (Hindi, Indonesian, Japanese, Korean, Malay, Thai, Vietnamese, and Chinese) and English. Each A-STAR member contributed one or more of the following spoken language technologies: automatic speech recognition, machine translation, and text-to-speech through Web servers. The system was designed to translate common spoken utterances of travel conversations from a given source language into multiple target languages in order to facilitate multiparty travel conversations between people speaking different Asian languages. It covers travel expressions including proper nouns that are names of famous places or attractions in Asian countries. In this paper, we describe the issues of developing spoken language technologies for Asian languages, and discuss the difficulties involved in connecting different heterogeneous spoken language translation systems through Web servers. This paper also presents speech-translation results including subjective evaluation, from the first A-STAR field testing which was carried out in July 2009. [Copyright &y& Elsevier]

Sustainable remediation requires a balanced decision-making process in which environmental, economic and social aspects of different remediation options are all considered together and the optimum remediation solution is selected. More attention has been paid to the evaluation of environmental and economic aspects, in particular to reduce the human and environmental risks and the remediation costs, to the exclusion of social aspects of remediation. This paper investigates how social aspects are currently considered in sustainability assessments of remediation projects. A selection of decision support tools (DSTs), used for the sustainability assessment of a remediation project, is analyzed to define how social aspects are considered in those tools. The social indicator categories of the Sustainable Remediation Forum – United Kingdom (SuRF-UK), are used as a basis for this evaluation. The consideration of social aspects in the investigated decision support tools is limited, but a clear increase is noticed in more recently developed tools. Among the five social indicator categories defined by SuRF-UK to facilitate a holistic consideration of social aspects of a remediation project only “Human health and safety” is systematically taken into account. “Neighbourhood and locality” is also often addressed, mostly emphasizing the potential disturbance caused by the remediation activities. However, the evaluation of ‘Ethics and Equality’, Communities and community involvement’, and ‘Uncertainty and evidence’ is often neglected. Nevertheless, concrete examples can be found in some of the investigated tools. Specific legislation, standard procedures, and guidelines that have to be followed in a region or country are mainly been set up in the context of protecting human and ecosystem health, safety and prevention of nuisance. However, they sometimes already include some of the aspects addressed by the social indicators. In this perspective the use of DST to evaluate the sustainability of a site remediation project, should be tuned to the legislation, guidelines and procedures that are in force in a specific country or region. [ABSTRACT FROM AUTHOR]

Abstract: Effective task scheduling is essential for obtaining high performance in heterogeneous computing systems (HCS). However, finding an effective task schedule in HCS, requires the consideration of the heterogeneity of computation and communication. To solve this problem, we present a list scheduling algorithm, called Heterogeneous Earliest Finish with Duplicator (HEFD). As task priority is a key attribute for list scheduling algorithm, this paper presents a new approach for computing their priority which considers the performance difference in target HCS using variance. Another novel idea proposed in this paper is to try to duplicate all parent tasks and get an optimal scheduling solution. The comparison study, based on both randomly generated graphs and the graphs of some real applications, shows that our scheduling algorithm HEFD significantly surpasses other three well-known algorithms. [Copyright &y& Elsevier]

Abstract: This paper describes our approach for the design and development of application systems for early stages of information design tasks. We view a computational tool as something that provides materials with which a designer interacts to create a situation that talks back to the designer. The interaction design of a tool, that is, the representations a user can generate and how the user can manipulate them with the tool, influences a user''s cognitive processes. The tool''s interaction design thus either fosters or hinders creativity in the early stages of information design. Our approach toward the interaction design of a tool for fostering creativity is first to understand the nature of early stages of information design tasks. We discuss four issues in support of the early stages of design based on theories in design and in human–computer interaction: (1) that available means of externalizations influence designers in deciding which courses of actions to take; (2) that designers generate and interact with not only a partial representation of the final artefact but also various external representations; (3) that designers produce externalizations to express a solution as well as to interpret the situations; and (4) that a design task proceeds as a hermeneutic circle—that is, designers proceed with projected meanings of representations and gradually revise and confirm those meanings. The above theoretical account of early stages of information design tasks has led us to identify three interaction design principles for tools for the early stages of information design: interpretation-rich representations, representations with constant grounding and interaction methods for hands-on generation and manipulation of the representations. To illustrate our point, we take ART#001, a tool for the early stages of writing, to apply the interaction design principles and examine how the interaction design of the tool fosters creativity in the early stages of information design. The paper concludes with a discussion of how we generalize the approach and build a framework to design and develop application systems for fostering creativity in the early stages of information design. [Copyright &y& Elsevier]

Abstract: Exploiting spatial and temporal locality is essential for obtaining high performance on modern computers. Writing programs that exhibit high locality of reference is difficult and error-prone. Compiler researchers have developed loop transformations that allow the conversion of programs to exploit locality. Recently, transformations that change the memory layouts of multi-dimensional arrays—called data transformations—have been proposed. Unfortunately, both data and loop transformations have some important drawbacks. In this work, we present an integrated framework that uses loop and data transformations in concert to exploit the benefits of both approaches while minimizing the impact of their disadvantages. Our approach works inter-procedurally on acyclic call graphs, uses profile data to eliminate layout conflicts, and is unique in its capability of resolving conflicting layout requirements of different references to the same array in the same nest and in different nests for regular array-based applications. The optimization technique presented in this paper has been implemented in a source-to-source translator. We evaluate its performance using standard benchmark suites and several math libraries (complete programs) with large input sizes. Our experimental results show that the proposed approach improves the performance of the applications optimized by using the current state-of-the-art techniques by 8.2% on the average. This reduction comes from three important characteristics of the technique, namely, resolving layout conflicts between references to the same array in a loop nest, determining a suitable order to propagate layout modifications across loop nests, and propagating layouts between different procedures in the program—all in a unified framework. The locality optimization technique presented in this paper tries to exploit locality in the innermost loop positions. This strategy, in most cases, generates dependence-free outer loops, which can be safely parallelized. [Copyright &y& Elsevier]

Abstract: This paper presents a total ordering protocol for group communication systems with multiple overlapping groups. Our protocol takes advantages of the simplicity of the sequencer-based approach, but employs multiple sequencers to achieve better load balance. For a given message, the sequencer of the destination group constructs a sequencing array by requesting for relative delivery positions from the sequencers of the overlapping groups. The sequencing array is used by any receiving process to determine the delivery sequence of the message. The notion of logical clock is used for determining the relative delivery sequences of the messages. The coordination between the sequencers is performed in a simple, asynchronous and non-blocking manner. The delivery operation at a receiving process is very simple, and a message can be delivered as soon as it becomes deliverable. These factors amount to a significant saving of the computing and communication overhead for the system. As the protocol demands the minimum effort from the group members it is suitable for mobile computing environment in which mobile devices are typically tight on resources. In the paper, we also present some ways to enhance the performance of the system. Extension of the protocol to encompass the preservation of causality, the dynamic group membership and the failure recovery is included in the paper. [Copyright &y& Elsevier]

Many distributed applications must meet stringent performance requirements even when the performance characteristics of the underlying systems and networks vary significantly at runtime. Runtime adaptation can be used to tolerate such changes, but sophisticated adaptive distributed programs can be extremely challenging to design, implement and debug. This paper proposes a language called Program Control Language (PCL) that provides a novel means of specifying adaptations in distributed applications. PCL is based on an abstract, global representation of a distributed program (a static task graph), which enables a programmer to reason about and to describe a wide range of application-specific adaptation strategies at a high level, using a few key mechanisms. PCL provides simple high-level syntax for local and remote adaptation operations, local and remote performance monitoring (and aggregation), and for performing adaptations synchronously or asynchronously with respect to the execution of the application process initiating the adaptation. The global task graph representation enables remote performance metrics and adaptation operations to be specified in simple global terms by any process, and the compiler and runtime system automatically perform the communication and synchronization required for the remote operations. The paper describes the conceptual adaptation framework, the PCL language, and our implementation of the PCL compiler and runtime system. The paper uses three adaptative applications examples to illustrate the capabilities and benefits of PCL, and to show experimentally that the performance overheads of using PCL for implementing an adaptive application are negligible. [Copyright &y& Elsevier]

This paper describes the results of a research project aimed at implementing a ‘realistic’ 3D Embodied Agent that can be animated in real-time and is ‘believable and expressive’: that is, able to coherently communicate complex information through the combination and the tight synchronisation of verbal and nonverbal signals. We describe, in particular, how we ‘animate’ this Agent (that we called Greta) so as to enable her to manifest the affective states that are dynamically activated and de-activated in her mind during the dialog with the user. The system is made up of three tightly interrelated components:

In the past few years, as the number of dialogue systems has increased, there has been an increasing interest in the use of natural language generation in spoken dialogue. Our research assumes that trainable natural language generation is needed to support more flexible and customized dialogues with human users. This paper focuses on methods for automatically training the sentence planning module of a spoken language generator. Sentence planning is a set of inter-related but distinct tasks, one of which is sentence scoping, i.e., the choice of syntactic structure for elementary speech acts and the decision of how to combine them into one or more sentences. The paper first presents SPoT, a trainable sentence planner, and a new methodology for automatically training SPoT on the basis of feedback provided by human judges. Our methodology is unique in neither depending on hand-crafted rules nor on the existence of a domain-specific corpus. SPoT first randomly generates a candidate set of sentence plans and then selects one. We show that SPoT learns to select a sentence plan whose rating on average is only 5% worse than the top human-ranked sentence plan. We then experimentally evaluate SPoT by asking human judges to compare SPoT''s output with a hand-crafted template-based generation component, two rule-based sentence planners, and two baseline sentence planners. We show that SPoT performs better than the rule-based systems and the baselines, and as well as the hand-crafted system. [Copyright &y& Elsevier]

This paper identifies two classes of communication patterns that occur in distributed computations and explores their properties. It first examines local patterns, primarily IO and OI intervals, that occur at nodes in distributed computations. These local patterns form building blocks that are then used to define the global patterns, termed segments and paths, that occur across nodes in distributed computations. By controlling the predicates on the local patterns used to define segments and paths, various types of segments and paths can be defined. While a causal chain captures only the causality relation, it turns out that some of the other message sequences that do not capture causality also play a significant role in the analysis of a distributed computation. The paper presents a framework and shows that a number of key concepts and structures characterizing distributed computations are specific instantiations of the communication patterns identified in the framework. [Copyright &y& Elsevier]

Sustainability reports may play an important role as a supporting tool in the transition of organisations towards more circular economy models, since their content can help to measure, monitor and communicate the organisations' transition and to establish goals in the short/medium term. The aim of this study is to determine whether it is possible to calculate indicators capable of measuring the transition of organisations towards circularity from the information that they are currently communicating in their Corporate Sustainability Reports (CSRs), and what information would need to be incorporated in these reports to successfully carry out this procedure. To this end, by applying a three-step methodology, 34 indicators grouped into 10 categories were proposed to measure the level of circularity of organisations. This was completed with a detailed proposal of units/metrics to measure the indicators, based on those that organisations commonly use in their CSRs. For this purpose, information from 8 international programmes/frameworks that measure circularity at the territorial level was combined with circularity information that organisations are currently communicating in their CSRs. Finally, the proposed set of indicators and metrics were applied to a Spanish organisation dedicated to the forestry and paper sector with a CSR based on GRI-Standards. The results demonstrated that 25 of the 34 proposed indicators (74%) can be measured directly using the information included in the CSRs. • Which indicators measure the advance of organisations towards circularity? • Which information organisations communicate in their Sustainability Reports (CSR)? • Can be circular indicators calculated using data from CSR? • Case study: 74% of the circular indicators can be calculated using data from CSR. [ABSTRACT FROM AUTHOR]

The abundance of communication technology, such as the omnipresence of cell phones, has not only increased our ability to reach people anytime anywhere, but also the likelihood of being interrupted. As a result, there is value in understanding how to design technology so that gains are realized from desired interruptions, while the losses from unwanted interruptions are minimized. This paper presents the findings of two complementary field studies, one quantitative and the other qualitative, exploring how the provision of additional incoming cell phone call information impacts people׳s interruption decision making. These studies were enabled by, Telling Calls , a research application built to enable users to provide and receive information such as what the call is about and the caller׳s circumstances. The qualitative study showed how the additional call information helps people make informed call handling decisions and acts as an aid to effective conversation. The quantitative study elucidated these findings and showed that reducing the uncertainty about the nature of an incoming call improves people׳s ability to predict the value of an interruption. By combining these diverse research approaches: (1) theory instantiation through tool building; (2) context-aware surveys; and (3) semi-structured interviews, we were able to gain unique insights into the nature of interruption management in the wild, and related design implications. [ABSTRACT FROM AUTHOR]

Abstract: Trust has been identified as a critical relationship component in contexts of high uncertainty and complexity such as wildfire management, and as a primary factor in public support for wildland fire management strategies. However, little attention has been paid to identifying and comparing factors across fire management stages (i.e. before, during, after a fire) that may influence trust between community members and fire management agencies. This paper attempts to address this gap by exploring factors affecting community-agency trusting relationships before, during and after a wildfire event. We draw upon 26 semi-structured interviews with 38 residents of a community directly impacted by fires in December 2006 and January 2007 in Victoria, Australia. Communication, cooperation, trustworthiness, and integration of local concerns and knowledge influenced trust in more than one fire management stage. Institutional structures and reduction of uncertainty were particularly strong influences during a fire. After a fire, resolving negative outcomes and immediately meeting perceived needs arising from the fire were factors unique to this stage. [Copyright &y& Elsevier]

Abstract: In this paper, the acoustic-perceptual effects of air sacs are investigated. Using an adaptive hearing experiment, it is shown that air sacs reduce the perceptual effect of vowel-like articulations. Air sacs are a feature of the vocal tract of all great apes, except humans. Because the presence or absence of air sacs is correlated with the anatomy of the hyoid bone, a probable minimum and maximum date of the loss of air sacs can be estimated from fossil hyoid bones. Australopithecus afarensis still had air sacs about 3.3 Ma, while Homo heidelbergensis, some 600 000 years ago and Homo neandethalensis some 60 000 years ago, did no longer. The reduced distinctiveness of articulations produced with an air sac is in line with the hypothesis that air sacs were selected against because of the evolution of complex vocal communication. This relation between complex vocal communication and fossil evidence may help to get a firmer estimate of when speech first evolved. [Copyright &y& Elsevier]

Abstract: In this paper we present Turk-2, a hybrid multi-modal chess player with a robot arm and a screen-based talking head. Turk-2 can not only play chess, but can see and hear the opponent, can talk to him and display emotions. We were interested to find out if a simple embodiment with human-like communication capabilities enhances the experience of playing chess against a computer. First, give an overview of the development road to multi-modal communication with computers. Then we motivate our research with a hybrid system, we introduce the architecture of Turk-2, we describe the human experiments and its evaluation. The results justify that multi-modal interaction makes game playing more engaging, enjoyable – and even more effective. These findings for a specific game situation provide yet another evidence of the power of human-like interaction in turning computer systems more attractive and easier to use. [Copyright &y& Elsevier]

Abstract: In computer-mediated communication, participants often experience a loss of information that would have been conveyed by non-verbal means in a face-to-face communication. They need to compensate for this loss by being more verbose which may have a negative impact on the efficiency of communication or give rise to misunderstandings. In this paper, we present a computer system that augments the imagery perceived from the remote site with additional visual information and that can be controlled by using a Nintendo Wiimote game controller. Our prototype illustrates our approach how a system might be able to partially compensate for the information typically lost in conventional video conferencing where deictic gestures cannot be relayed properly to the remote site. Concerning user acceptance, our user tests also show that the visualization technique is crucial which is used for highlighting the objects or persons that are being pointed at. Adequate visualization techniques based on non-photorealistic rendering are proposed. [Copyright &y& Elsevier]

Abstract: Rewriting systems working on words with a center marker are considered. The derivation is done by erasing a prefix or a suffix and then adding a prefix or a suffix. This models a communication of two stacks according to a fixed protocol defined by the choice of rewriting rules. The paper systematically considers different cases of these systems and determines their expressive power. Several cases are identified where very restricted communication surprisingly yields computational universality. [ABSTRACT FROM AUTHOR]

Abstract: A fundamental problem in distributed computing is performing a set of tasks despite failures and delays. Stated abstractly, the problem is to perform tasks using failure-prone processors. This paper studies the efficiency of emulating shared-memory task-performing algorithms on asynchronous message-passing processors with quantifiable message latency. Efficiency is measured in terms of work and communication, and the challenge is to obtain subquadratic work and message complexity. While prior solutions assumed synchrony and constant delays, the solutions given here yield subquadratic efficiency with asynchronous processors when the delays and failures are suitably constrained. The solutions replicate shared objects using a quorum system, provided it is not disabled. One algorithm has subquadratic work and communication when the delays and the number of processors, , owning object replicas, are . It tolerates crashes. It is also shown that there exists an algorithm that has subquadratic work and communication and that tolerates failures, provided message delays are sublinear. [Copyright &y& Elsevier]

Abstract: The varying degree of mobility of Mesh Clients has provided much more flexibility in Wireless Mesh Networks, and establishing an Authentic Association among entities is a non-trivial problem. In this paper, we introduce a Polynomial Based scheme which provides pair-wise connectivity, low communication, marginal storage overhead and high scalability while making on the fly Authentic Association feasible. The proposed scheme is also observed to be resilient against both traffic analysis and node capture attacks. [Copyright &y& Elsevier]

Abstract: In this paper, we study sixteen communication primitives, arising from the combination of four useful programming features: synchronism (synchronous vs asynchronous primitives), arity (monadic vs polyadic data), communication medium (message passing vs shared dataspaces) and pattern-matching. Some of these primitives have already been used in at least one language which has appeared in the literature; however, to reason uniformly on such primitives, we plug them into a common framework based on the π. By means of possibility/impossibility of ‘reasonable’ encodings, we compare every pair of primitives to obtain a hierarchy of languages based on their relative expressive power. [Copyright &y& Elsevier]

Abstract: In SONET/WDM networks, a high-speed wavelength channel is usually shared by multiple low-rate traffic demands to make efficient use of the wavelength capacity. The multiplexing is known as traffic grooming and performed by SONET Add-Drop Multiplexers (SADM). The maximum number of low-rate traffic demands that can be multiplexed into one wavelength channel is called grooming factor. Since SADMs are expensive, a key optimization goal of traffic grooming is to minimize the total number of SADMs in order to satisfy a given set of traffic demands. As an important communication traffic pattern, all-to-all traffic has been widely studied for the traffic grooming problem. In this paper, we study the regular traffic pattern, which is considered as a generalization of the all-to-all traffic pattern. We focus on the Unidirectional Path-Switched Ring (UPSR) networks. We prove that the traffic grooming problem is NP-hard for the regular traffic pattern in UPSR networks, and show that the problem does not admit a Fully Polynomial Time Approximation Scheme (FPTAS). We further prove that the problem remains NP-hard even if the grooming factor is any fixed value chosen from a subset of integers. We also propose a performance guaranteed algorithm to minimize the total number of required SADMs, and show that the algorithm achieves a better upper bound than previous algorithms. Extensive simulations are conducted, and the empirical results validate that our algorithm outperforms the previous ones in most cases. In addition, our algorithm always uses the minimum number of wavelengths, which are precious resources as well in optical networks. [Copyright &y& Elsevier]

Abstract: This paper is concerned with the design, implementation, and evaluation of algorithms for communication partner identification in mobile agent-based distributed job workflow execution. We first describe a framework for distributed job workflow execution over the Grid: the Mobile Code Collaboration Framework (MCCF). Based on the study of agent communications during a job workflow execution on MCCF, we identify the unnecessary agent communications that degrade the system performance. Then, we design a novel subjob grouping algorithm for preprocessing the job workflow''s static specification in MCCF. The obtained information is used in both static and dynamic algorithms to identify partners for agent communication. The mobile agent dynamic location and communication based on this approach is expected to reduce the agent communication overhead by removing unnecessary communication partners during the dynamic job workflow execution. The proof of the dynamic algorithm''s correctness and effectiveness are elaborated. Finally, the algorithms are evaluated through a comparison study using simulated job workflows executed on a prototype implementation of the MCCF on a LAN environment and an emulated WAN setup. The results show the scalability and efficiency of the algorithms as well as the advantages of the dynamic algorithm over the static one. [Copyright &y& Elsevier]

Abstract: Wireless sensor networks are inherently plagued by problems of node failure, interference to communications from environmental noise and energy-limited sensor motes. These problems pose conflicting issues in the design of suitable routing protocols. Several existing reliable routing protocols exploit message broadcast redundancy and hop count as routing metrics and their performance trade-offs are revealed during simulation. In this paper, we study and analyse related design issues in proposed efficient and reliable routing protocols that attempt to achieve reliable and efficient communication performance in both single- and multi-hub sensor networks. Simulation results of four such routing protocols show that routing performance depends more on optimal (near-optimal) routing in single hub than in multi-hub networks. Our work also shows that optimal (near-optimal) routing is better achieved when historical metrics like packet distance traversed and transmission success are also considered in the routing protocol design. [Copyright &y& Elsevier]

Abstract: This paper proposes an information theoretic criterion for comparing two partitions, or clusterings, of the same data set. The criterion, called variation of information (VI), measures the amount of information lost and gained in changing from clustering to clustering . The basic properties of VI are presented and discussed. We focus on two kinds of properties: (1) those that help one build intuition about the new criterion (in particular, it is shown the VI is a true metric on the space of clusterings), and (2) those that pertain to the comparability of VI values over different experimental conditions. As the latter properties have rarely been discussed explicitly before, other existing comparison criteria are also examined in their light. Finally we present the VI from an axiomatic point of view, showing that it is the only “sensible” criterion for comparing partitions that is both aligned to the lattice and convexely additive. As a consequence, we prove an impossibility result for comparing partitions: there is no criterion for comparing partitions that simultaneously satisfies the above two desirable properties and is bounded. [Copyright &y& Elsevier]

Abstract: Communication and collaborative decision-making are critical activities in safety-critical systems such as marine transportation. As a result, new group technologies have been introduced to enhance communication and decision-making in these settings. Unfortunately, little research examining the impact of these new collaborative technologies has been undertaken, and most of it has been undertaken in laboratory environments, rather than in operational or safety-critical settings. Two primary differences of the operational setting in this study suggest that results may differ from studies undertaken in laboratory environments: (1) the system has a strong hierarchical organization and culture with clearly defined roles and (2) roles in the system are associated with different information access privileges. This paper explores the impact of introducing new technology on communication and collaboration between dispersed decision-making groups in marine transportation, and focuses on the differences in results observed in this operational setting. [Copyright &y& Elsevier]

Abstract: During the last two decades the design and development of total order (TO) communications has been one of the main research topics in dependable distributed computing. The huge amount of research work has produced several TO specifications and a wide variety of TO implementations with different guarantees whose differences are often left hidden or unclear. This paper presents a systematic classification of six distinct TO specifications based on a well-defined formal framework. The classification allows us (i) to define in a formal way the differences among the behaviors of faulty and correct processes admitted by each specification, and (ii) to easily match TO implementations with respect to their enforced specification. The classification is applied to study the properties of eight variations of TO implementations based on a fixed sequencer given in a well-known context, namely primary component group communication systems. [Copyright &y& Elsevier]

Abstract: Creativity might be viewed as any process which results in a novel and useful product. People use computers for creative tasks; they flesh out ideas for text, graphics, engineering solutions, etc. Computer programming is an especially creative activity, but few tools for programming aid creativity. Computers can be designed to foster creativity as well. As a start, all computer programs should help users enumerate ideas, remember alternatives and support various ways to compare them. More sophisticated thinking aids could implement other successful techniques as well. Most computers are used in solitude; however, people depend on social supports for creativity. User scenarios can provide the important social support and gracious cues normally offered by collaborators that keep people motivated and help them consider alternatives. People also use computers to build community and to communicate. Computers should also support and filter these potentially creativity-enhancing communication acts. User-interface designers are so busy exposing features and fighting bugs that they might ignore their users’ needs for motivation and creativity support. This paper develops the notion that creativity and motivation enhancement can easily be aligned with the design of high-quality human–computer interaction. User interface toolkits and evaluations should include support for motivation and creativity-enhancing approaches. [Copyright &y& Elsevier]

Abstract: This paper provides new insights on the semantic characteristics of two and three noun compounds. An analysis is performed using two sets of semantic classification categories: a list of 8 prepositional paraphrases previously proposed by Lauer [Designing statistical language learners: experiments on noun compounds, Ph.D. Thesis, Macquarie University, Australia] and a new set of 35 semantic relations introduced by us. We show the distribution of these semantic categories on a corpus of noun compounds and present several models for the bracketing and the semantic classification of noun compounds. The results are compared against state-of-the-art models reported in the literature. [Copyright &y& Elsevier]

Abstract: This paper describes a distributional approach to the semantics of verb particle constructions (e.g., put up, make off). In common with many other varieties of multiword expression, verb–particles vary in the extent to which the component words of the phrase contribute independent meanings. A technique for automatically detecting when and how a component word is making such a contribution would be very useful in the construction of lexicons. Using verb particles as a test case we suggest that a comparison of the lexical contexts in which the phrase and the components occur can provide us with vital information in this regard. Our hypothesis is that the lexical contexts in which a given verb–particle construction occurs across a corpus will be more similar to those of a given component word if that component word is contributing an independent meaning to the phrase. We demonstrate a convincing correlation between contextual similarity and the compositionality judgements of expert and non-expert annotators. [Copyright &y& Elsevier]

Abstract: Many scientific applications require array redistribution when the programs run on distributed memory parallel computers. It is essential to use efficient algorithms for redistribution, otherwise the performance of the programs will degrade considerably. The redistribution overheads consist of two parts: index computation and inter-processor communication. If there is no communication scheduling in a redistribution routine, the inter-processor communication will incur a larger communication idle time when there exists node contention and/or difference among message lengths during one particular communication step. In order to solve this problem, in this paper, we propose an efficient scheduling scheme that not only minimizes the number of communication steps and eliminates node contention, but also minimizes the difference of message lengths in each communication step. Thus, the communication idle time is reduced in redistribution routines. [Copyright &y& Elsevier]

A boolean function f(x1,…,xn) with xi∈{0,1}m for each i is hard if its nondeterministic multiparty communication complexity (introduced in [Proceedings of the 30th IEEE FOCS, 1989. p. 428]), C(f), is at least nm. Note that C(f)⩽nm for each f(x1,…,xn) with xi∈{0,1}m for each i. A boolean function is very hard if it is hard and its complementary function is also hard. In this paper, we show that randomly chosen boolean function f(x1,…,xn) with xi∈{0,1}m for each i is very hard with very high probability (for n⩾3 and m large enough). In [Proceedings of the 12th Symposium on Theoretical Aspects of Computer Science, LNCS 900, 1995, p. 350], it has been shown that if f(x1,…,xk,…,xn)=f1(x1,…,xk)·f2(xk+1,…,xn), where C(f1)>0 and C(f2)>0, then C(f)=C(f1)+C(f2). We prove here an analogical result: If f(x1,…,xk,…,xn)=f1(x1,…,xk)⊕f2(xk+1,…,xn) then DC(f)=DC(f1)+DC(f2), where DC(g) denotes the deterministic multiparty communication complexity of the function g and “⊕” denotes the parity function. [Copyright &y& Elsevier]

Coteries are an effective tool for enforcing mutual exclusion in distributed systems. Communication delay is an important metric to measure the performance of a coterie. The topology of the interconnection network in a distributed system also has an impact on its performance. The k-dimensional folded Petersen graph, a graph with 10k nodes and diameter 2k, qualifies as a good network topology for large distributed systems. In this paper, we present a delay optimal coterie on the k-dimensional folded Petersen graph, FPk. For any positive integer k, the coterie has message complexity 4k and delay k. Moreover, this coterie is not vote-assignable. [Copyright &y& Elsevier]

For real-time communication, we must be able to guarantee timely delivery of messages. In recent years, improvements in technology have made possible switch-based local area networks (LANs) and system area networks (SANs) that use wormhole switching, a pipelined switching technique which permits significantly shorter network latencies and higher throughputs than traditional store-and-forward packet switching. This paper proposes a model for real-time communication in such wormhole networks based on the use of real-time wormhole channels, which are simplex virtual circuits in wormhole networks with certain real-time guarantees. A distinguishing feature of our model is that it can be used in existing wormhole networks without any special hardware support. Preliminary delay analysis and properties are shown for the proposed real-time wormhole channel model. A practical quadratic time complexity algorithm is shown for determining the feasibility of a set of wormhole channels. Finally, as an example of the utility of our model, actual parameter values obtained from experiments on a Myrinet switch-based network are used to determine if real-time guarantees are possible for an example set of real-time traffic streams intermixed with nonreal-time traffic. [Copyright &y& Elsevier]

With recent advances in high-speed networks, distributed heterogeneous computing has emerged as an attractive computational paradigm. Wide-area grid infrastructures will enable distributed applications—such as video conferencing and distributed interactive simulation—to seamlessly integrate collections of heterogeneous workstations, multiprocessors, and mobile nodes. The underlying network is typically a collection of several heterogeneous links, of different networking technologies. Such a heterogeneous network is also typical in local area workstation clusters, which are increasingly being used as alternatives to parallel computing systems. This paper introduces a framework for developing efficient collective communication schedules over such heterogeneous networks. We focus on application-level communication, between processes of a parallel program. Our framework consists of analytical models of the heterogeneous system, scheduling algorithms for the collective communication pattern, and performance evaluation mechanisms. We show that previous models, which considered node heterogeneity but ignored network heterogeneity, can lead to solutions which are worse than the optimal by an unbounded factor. We then introduce an enhanced communication model, and develop three heuristic algorithms for the broadcast and multicast patterns. The completion time of the schedule is chosen as the performance metric. The heuristic algorithms are fastest edge first (FEF), earliest completing edge first (ECEF), and ECEF with look-ahead. For small system sizes, we find the optimal solution using exhaustive search. Our simulation experiments indicate that the performance of our heuristic algorithms is close to optimal. For performance evaluation of larger systems, we have also developed a simple lower bound on the completion time. Our heuristic algorithms achieve significant performance improvements over previous approaches. [Copyright &y& Elsevier]

High-performance computing applications with data-driven communication and computation characteristics require synchronization routines in the form of eureka, barrier, or termination synchronization. In this paper, we consider termination synchronization for two different execution models, the AP and the APS model. In the AP model, processors are either active or passive and a passive processor can be made active by another active processor. In the APS model, processors can also be in a server state. A passive processor entering the server state does not become active again. In addition, a server processor cannot change the status of other processors. We describe and analyze solutions for both models and present experimental work highlighting the differences between the models. We show that in almost all situations the use of an AP algorithm to detect termination in an APS environment will result in loss of performance. Our experimental work on the Cray T3E provides insight into where and why this performance loss occurs. [Copyright &y& Elsevier]

A checkpoint of a process involved in a distributed computation is said to be useful if it is part of a consistent global checkpoint. In this paper, we present a quasi-synchronous checkpointing algorithm that makes every checkpoint useful. We also present an efficient asynchronous recovery algorithm based on the checkpointing algorithm. The checkpointing algorithm allows the processes to take checkpoints asynchronously and also forces the processes to take additional checkpoints in order to make every checkpoint useful. The recovery algorithm can handle concurrent failure of multiple processes. The recovery algorithm has no domino effect and a failed process needs only to roll back to its latest checkpoint and request the other processes to roll back to a consistent checkpoint. Messages are only selectively logged to cope with various types of message abnormalities that arise due to rollback and hence results in low message logging overhead. Unlike some existing algorithms, our algorithm does not use vector timestamps for tracking dependency between checkpoints and hence results in low message overhead during failure-free operation. Moreover, a process can asynchronously decide garbage checkpoints and delete them from the stable storage—garbage checkpoints are the checkpoints that are no longer required for the purpose of recovery. [Copyright &y& Elsevier]

This paper reports on research in workplace issues encountered by knowledge workers in cubicle environments, and on BlueSpace, a prototype workspace with the goal of addressing workers'' critical needs for privacy, concentration and personalization. To inform the design process, more than 50 on-site interviews with knowledge workers were conducted at six companies ranging from dot.com startups to Fortune 100 corporations. Several common requirements emerged including the need for a sense of control of one''s workspace, the ability to create privacy on-demand to improve concentration and minimize unwanted interruptions, as well as in-place support for dyadic interactions. Many other common workplace complaints (e.g. too hot, too cold, too noisy) were found to be derivative of the major requirements for individual control and privacy. [Copyright &y& Elsevier]

In this paper, we describe how language generation and speech synthesis for spoken dialog systems can be efficiently integrated under a weighted finite state transducer architecture. Taking advantage of this efficiency, we show that introducing flexible targets in generation leads to more natural sounding synthesis. Specifically, we allow multiple wordings of the response and multiple prosodic realizations of the different wordings. The choice of wording and prosodic structure are then jointly optimized with unit selection for waveform generation in speech synthesis. Results of perceptual experiments show that by integrating the steps of language generation and speech synthesis, we are able to achieve improved naturalness of synthetic speech compared to the sequential implementation. [Copyright &y& Elsevier]

Prosody modeling is critical in developing a Concept-to-Speech (CTS) system where both Natural Language Generation (NLG) and Speech Synthesis are used to automatically generate natural, coherent speech. In this paper, we empirically verify the usefulness of various natural language features in prosody modeling. Three groups of features are investigated: semantic, syntactic, and surface features produced by SURGE, a general-purpose surface natural language generator for English, deep semantic, and discourse features that are available during the domain modeling and content planning phases of generation, and information-based measures statistically derived from text. Our experiments identify which of this large set of features are effective in prosody modeling. This work represents an important step towards building a comprehensive prosody model for CTS systems that employ general NLG. This investigation is conducted in the context of MAGIC, a medical application that involves automatic speech and graphics generation. [Copyright &y& Elsevier]

We describe a corpus-based approach to natural language generation (NLG). The approach has been implemented as a component of a spoken dialog system and a series of evaluations were carried out. Our system uses n-gram language models, which have been found useful in other language technology applications, in a generative mode. It is not yet clear whether the simple n-grams can adequately model human language generation in general, but we show that we can successfully apply this ubiquitous modeling technique to the task of natural language generation for spoken dialog systems. In this paper, we discuss applying corpus-based stochastic language generation at two levels: content selection and sentence planning/realization. At the content selection level, output utterances are modeled by bigrams, and the appropriate attributes are chosen using bigram statistics. In sentence planning and realization, corpus utterances are modeled by n-grams of varying length, and new utterances are generated stochastically. Through this work, we show that a simple statistical model alone can generate appropriate language for a spoken dialog system. The results describe a promising avenue for using a statistical approach in future NLG systems. [Copyright &y& Elsevier]

In concept-to-speech systems, spoken output is generated on the basis of a text that has been produced by the system itself. In such systems, linguistic information from the text generation component may be exploited to achieve a higher prosodic quality of the speech output than can be obtained in a plain text-to-speech system. In this paper we discuss how information from natural language generation can be used to compute prosody in a concept-to-speech system, focusing on the automatic marking of contrastive accents on the basis of information about the preceding discourse. We discuss and compare some formal approaches to this problem and present the results of a small perception experiment that was carried out to test which discourse contexts trigger a preference for contrastive accent, and which do not. Finally, we describe a method for marking contrastive accent in a generic concept-to-speech system called D2S. In D2S, contrastive accent is assigned to generated phrases expressing different aspects of similar events. Unlike in previous approaches, there is no restriction on the kind of entities that may be considered contrastive. This is in line with the observation that, given the `right'' context, any two items may stand in contrast to each other. [Copyright &y& Elsevier]

This paper describes the response planning and generation components of the mercury flight reservation system, a mixed-initiative spoken dialogue system that supports both voice-only interaction and multi-modal interaction augmenting spoken inputs with typing or clicking at a displayed Web page. mercury is configured using the Galaxy Communicator architecture (), where a suite of servers interact via program control mediated by a central hub. Language generation is performed in two steps: response planning, or deep-structure generation, is carried out by the dialogue manager, and is well-integrated with other aspects of dialogue control; control flow is specified by a dialogue control table (). Response generation, or surface-form generation, is executed by a separate language generation server, under the guidance of a set of recursive generation rules and an associated lexicon (). The generation of the textual string for the graphical interface and the marked-up synthesis string for spoken outputs are controlled by a shared set of generation rules (). Thus there is a direct meaning-to-speech mapping that eliminates the need to analyze linguistic structure for synthesis. To date, we have collected over 25 000 utterances from users interacting with the mercury system. We report here on both the results of user satisfaction studies conducted by the National Institute of Standards and Technology (NIST), and on our own tabulation of a number of different measures of dialogue success. [Copyright &y& Elsevier]