bluuebunny/crossref_metadata_2025_split huggingface dataset:
TOPOLOGICAL CONSTRAINTS FOR SENSE OF DIRECTION
Authors: FLOCCHINI PAOLA , SANTORO NICOLA 
Published: May 2003

In a distributed system, each entity has a label (port number) associated to each of its neighbors. It is well known that if the labeling satisfies a global consistency property called Sense of Direction, the communication complexity of many distributed problem can be greatly reduced. This property is assumed to be present and it is implicitly used in most interconnection networks. In this paper we investigate the nature of the relationship between Sense of Direction and network topology. We first consider the class of labelings which only satisfy the requirement of local orientation; that is, at each node, the outgoing edges have distinct labels. We then consider the class of labelings which also satisfy edge symmetry; that is, there exists a correlation between the labels neighbors give to their connecting edge. This class includes most of used labelings. We completely characterize the interplay between topological constraints and consistency constraints for these two classes of labelings. In fact, for each class, we identify both the set of forbidden subgraphs and the set of feasible graphs, and we show that the characterization is complete.
PERMUTATION ROUTING AND SORTING ON THE RECONFIGURABLE MESH
Authors: RAJASEKARAN SANGUTHEVAR , MCKENDALL THEODORE 
Published: May 2003

In this paper we demonstrate the power of reconfiguration by presenting efficient randomized algorithms for both packet routing and sorting on a reconfigurable mesh connected computer. The run times of these algorithms are better than the best achievable time bounds on a conventional mesh. Many variations of the reconfigurable mesh can be found in the literature. We define yet another variation which we call as Mr. We also make use of the standard PARBUS model. We show that permutation routing problem can be solved on a linear array Mr of size n in [Formula: see text] steps, whereas n-1 is the best possible run time without reconfiguration. A trivial lower bound for routing on Mr will be [Formula: see text]. On the PARBUS linear array, n is a lower bound and hence any standard n-step routing algorithm will be optimal. We also show that permutation routing on an n×n reconfigurable mesh Mr can be done in time n+o(n) using a randomized algorithm or in time 1.25n+o(n) deterministically. In contrast, 2n-2 is the diameter of a conventional mesh and hence routing and sorting will need at least 2n-2 steps on a conventional mesh. A lower bound of [Formula: see text] is in effect for routing on the 2D mesh Mr as well. On the other hand, n is a lower bound for routing on the PARBUS and our algorithms have the same time bounds on the PARBUS as well. Thus our randomized routing algorithm is optimal upto a lower order term. In addition we show that the problem of sorting can be solved in randomized time n+o(n) on Mr as well as on PARBUS. Clearly, this sorting algorithm will be optimal on the PARBUS model. The time bounds of our randomized algorithms hold with high probability.
NEW RESULTS ON COMPUTABILITY OF RECURRENCE EQUATIONS
Authors: VERGE HERVE LE , SAOUTER YANNICK 
Published: May 2003

Systems of uniform recurrence equations were proposed by Karp et al.13 as a mean of automatically deriving programs for parallel architectures. Extensions of this formalism are used by many authors in systolic array synthesis. The computability of a system of recurrence equations is therefore of primary importance, and is considered as the first point to be examined when trying to implement an algorithm. This paper investigates the computability of recurrence equations and especially new results obtained in this area. We first recall the definitions of computability proposed by Karp et al.,13 Rao,31 Joinnault12 and Saouter et al.32 Then we correct and generalize those results. Finally, we give a new original proof for the undecidability of computability of non-uniform, non-conditional systems of recurrence equations.
SORT ORDER PROBLEMS IN RELATIONAL DATABASES
Authors: LARSEN KIM S. 
Published: May 2003

A relation of degree k can be sorted lexicographically in k! different ways, i.e., according to any one of the possible permutations of the schema of the relation. Such permutations are referred to as sort orders. When evaluating unary and binary relational algebra operators using sort-merge algorithms, sort orders fulfilling the constraints enforced by the operators are chosen for the operand relations. The relations are then sorted according to their assigned sort orders, and the result is obtained by merging. Should the operands already be sorted according to one of the permissible sort orders, then only a merging is required. The sort order of the result will depend on the sort orders of the operands. When evaluating whole relational algebra expressions, the result of one operation will be used as an operand to the next. It is desirable to choose sort orders in such a way that the result of one operation will automatically fulfill the requirements of the next. In general, one would like to find a minimal number of operators in the expression for which this cannot be obtained, bearing in mind the overall goal of minimizing the total work. We show that this problem is NP-hard, and that the corresponding decision problem is NP-complete. However, most simplifications of the original problem give rise to efficient algorithms. In fact, most frequently occurring queries can be analyzed in linear time in the size of the query. This is due to the fact that only a very limited number of subsets of all permutations of schemas can be encountered in the algorithms, which means that compact representations for these subsets can be found.
RECOGNITION OF SEED VARIETIES USING A TEMPORAL ORGANISATION MAP ANALYSIS OF ELECTROPHORETIC IMAGES
Authors: JEDRA M. , KHATTABI N. EL , LIMOURI M. , ESSAID A. 
Published: May 2003

This paper presents a method for seed varieties recognition using one-dimensional electrophoresis gels. It employs a neural network basically constituted of temporal organisation maps (TOM). The TOM model is a neural net which was initially developed for speech recognition. It can be trained to recognise words in speech by reference to the sound pattern over a sequence of time steps. Electrophoresis creates a set of bands in the gel, caused by migration of protein from the seed. Each seed variety generates a characteristic pattern. The bands are made visible by staining. They can then be imaged and digitised to create an input to a TOM, which treats the variation with distance along the lane in the same way as the time sequence for which it was originally employed. In this way the characteristic signature of a seed variety can be recognised. A set of 50 images — each containing 10 to 15 lanes — was used to train and test the performance of a neural network in recognising 75 cereal varieties. The network could achieve a recognition rate of 98%, provided that the gel was not distorted or cracked during heating or drying. Details of the design and training of the network are given.
ROLE OF GAP JUNCTION RESISTANCE IN RATE-INDUCED DELAY IN CONDUCTION IN A CABLE MODEL OF THE ATRIOVENTRICULAR NODE
Authors: JAMALEDDINE RABIH S. , VINET ALAIN 
Published: May 2003

A constant fast heart rate results in a time and rate dependent increase in AV nodal conduction time. The origin of this delay in conduction remains unknown due to limited access to corresponding cellular events. We have investigated the possible contribution of gap junction resistance in rate-induced delay in conduction using a one-dimensional model of the AV node. We use a cable that includes 100 cells: 30 AN cells, 40 N cells and 30 NH cells. The three cell types are modeled by varying the parameters of a modified Beeler Reuter ionic model. N cells have a low density of sodium current and are mainly activated by an ICa,L type current. Their resting potential is less negative and their upstroke slower than those of AN and NH cells. Cells are connected by gap junctions whose resistance is controlled by the intracellular calcium concentration. Stimuli are applied to the first AN cells. At a pacing rate of 400 ms, the gap junction resistance was AN 1.8 MΩ, N 32.0 MΩ and NH 3.6 MΩ and the total conduction time was 48 ms. Following a sudden decrease of cycle length from 400 ms to 250 ms, the conduction time progressively increased and reached a new steady-state of 77.7 ms after 800 beats. This increase of conduction time was mainly caused by a gradual increase of the gap junction resistance between N cells, which reached 46 MΩ at steady state. Rate and time dependent increase of conduction time was abolished when the gap junction resistances were kept constant. This model study suggests that the dynamic changes in gap junction resistance may play a key role in rate-induced AV nodal conduction delay.
MECHANISM OF ANODE BREAK EXCITATION IN THE HEART: THE RELATIVE INFLUENCE OF MEMBRANE AND ELECTROTONIC FACTORS
Authors: ROTH BRADLEY J. , CHEN JUN 
Published: May 2003

Two hypotheses for the mechanism of anode break excitation in cardiac tissue are electrotonic interaction between adjacent regions of depolarization and hyperpolarization, and a hyperpolarization-activated membrane current, if. We incorporate membrane kinetics proposed for if into the bidomain model with unequal anisotropy ratios. During unipolar stimulation, we find that: (1) The mechanisms of cathode make, cathode break, and anode make excitation are insensitive to if. (2) Both electrotonic interactions and if contribute to anode break excitation. In our simulations, if makes the dominant contribution. (3) Electrotonic interactions cause the "dip" in the anodal strength-interval curve. (4) Following anode break excitation, the wave front propagates in the direction perpendicular to the fibers. (5) if improves the agreement between the measured and calculated strength-interval curves. We suggest three experiments to determine the mechanism of anode break excitation: measure the site and timing of initial excitation, or use drugs to suppress if.
INTERFACIAL FRICTIONAL BEHAVIOR: CANCELLOUS BONE, CORTICAL BONE, AND A NOVEL POROUS TANTALUM BIOMATERIAL
Authors: Zhang Yongde , Ahn Peter B. , Fitzpatrick Daniel C. , Heiner Anneliese D. , Poggie Robert A. , Brown Thomas D. 
Published: May 2003

A laboratory test was undertaken to evaluate the interfacial frictional characteristics of cortical and cancellous bone, as well as a novel porous tantalum biomaterial (Hedrocel®, Implex Corp.). Three sets of tests were conducted to measure the friction coefficients of (1) bovine cancellous bone against bovine cortical bone; (2) net-shape formed porous tantalum against bovine cortical and cancellous bone; and (3) electron-discharge-machine formed (EDM'd) porous tantalum against bovine cortical and cancellous bone. The bovine cortical bone was tested in three conditions: periosteum-intact, periosteum-denuded and surface-flattened. An inclined plane apparatus was used to determine the coefficients of friction. By gradually increasing the substrate tilt, the angle of slippage was determined, and the friction coefficient was calculated.The average friction coefficients of cancellous bone against periosteum-intact, periosteum-denuded and surface-flattened cortical bone were 0.91±0.14, 0.61± 0.07 and 0.58±0.06, respectively. Porous tantalum specimens prepared from a preshaped vitreous carbon skeleton, when tested against periosteum-intact, periosteum-denuded and surface-flattened cortical bone, and against cancellous bone, had average friction coefficients of 1.10±0.18, 0.82±0.15, 0.86±0.11, and 0.98±0.17, respectively. Porous tantalum specimens prepared by electron-discharge machining, when tested against periosteum-intact cortical bone, periosteum-denuded cortical bone and cancellous bone, had average friction coefficients of 1.75±0.33, 0.74±0.07, and 0.88±0.09, respectively. The friction coefficient of the porous tantalum material was very high in comparison to natural bone autografts or allografts, and to conventional orthopedic implant coating materials (sintered beads and wire mesh). Other factors being equal, this high-friction characteristic would be expected to translate into higher initial stability of a porous tantalum implant, as compared to natural bone grafts.
ANATOMICAL STUDY FOR THE PATHOGENESIS OF ACROMIAL SPUR UTILIZING MACERATED SKELETONS
Authors: Noda M. , Mizuno K. 
Published: May 2003

In clarifying the pathogenesis of an acromial spur formation, sixty macerated whole body skeletons were studied by utilizing visual measurement. The criterion for judging the presence of spurs was determined as spurs: >3 mm. Spur formation at eight different extra-spinal skeletal bones was measured bilaterally. Additionally, the morphological features of acromial spurs were classified. Comparative study on the paired acromial spur, both in the length and the morphology, was demonstrated to be significantly symmetric. Moreover, in the case of bilateral giant acromial spur presence: >4 mm, three out of six were associated with skeletal hyperostosis. Impingement and overuse have been considered to be the common preceding factors in acromial spurs. Based on our study, two additional factors might be proposed. It may either be due to a local finding of diffuse idiopathic skeletal hyperostosis or to intrinsic factors.
EMS AS A MAINSTREAM BUSINESS TOOL: PERSPECTIVES FROM HONG KONG
Authors: COPELAND ANNE M. , LE CLUE SOPHIE 
Published: May 2003

The proliferation of global trade and commerce provides both challenges and opportunities for addressing transboundary pollution and furthering global sustainability. In addition to international policy instruments and legislation, standardised approaches to environmental management can improve environmental performance and reduce the escalating levels of pollution that are being experienced worldwide, and particularly in the Asia-Pacific region. In Hong Kong, 35 organisations have been certified to the ISO 14001 international environmental management system (EMS) standard, joining over 5000 more worldwide. While this trend is encouraging, Hong Kong's experience demonstrates that significant barriers exist for EMS to become a mainstream tool for small- and medium-sized enterprises (SMEs). As is it unlikely that certification will become mandatory at the international level, additional effort is therefore required to overcome these barriers, such as raising the awareness of all stakeholders to the benefits of the EMS and facilitating access to the necessary financial and technological assistance.
STRUCTURING LONG-TERM DECISIONS
Authors: ATHERTON ELIZABETH , FRENCH SIMON 
Published: May 2003

The public is demanding more democratic decision making processes that take into account their opinions and views. In order to make large societal decision making processes inclusive, it is necessary to find a way of communicating the issues involved in a decision without becoming swamped with the technical aspects. Many of the societal decisions that have to be made, e.g., about the greenhouse effect and radiation, have very long-term impacts, which make them even more complex. One of the more controversial issues in evaluating long-term impacts is the choice of discount rate, or indeed whether discounting is appropriate. When the decision is societal and there are many stakeholders, the debate about the discount rate can become very heated. Using exponential discounting focuses attention on the discount rate and does not help stakeholders explore their opinions and beliefs. Atherton and French (1998) suggested an alternative methodology based upon a time-era structuring of attributes. By dividing time into distinct eras and weighting these rather than applying one discount rate over the whole lifetime of the project, a seemingly more transparent way of dealing with time preferences was developed. To further investigate the acceptability of the methodology to a broad range of people, an interactive World Wide Web page was set up. The page was not context specific and talked about an undefined project, not a particular decision situation. The subjects were asked to define the time eras themselves and to weight them. They were then asked to indicate what had motivated their weights and finally they were asked how their weights would change if the issues changed. Most subjects found the ideas easy to comprehend and commented positively about the experiment. Seventy-five per cent of the subjects divided time into increasing intervals in line with the suggestions made in Atherton and French (1998). Sixty-five per cent of them had decreasing time era weights, but their weights decreased more slowly than those prescribed by constant discounting. This paper describes the results of the experiment, indicating the implications they may have for societal decision making.
THE PROJECT CYCLE AND THE ROLE OF EIA AND EMS
Authors: RIDGWAY BRONWYN 
Published: May 2003

This paper examines the potential interrelationships between the environmental impact assessment (EIA) and environmental management systems (EMS) process. It begins by looking at the project cycle and the role of EIA in the planning and design phase. The links between the initial environmental review phase of environmental management systems and the EIA report recommendations is examined and it is noted that the format of EIA reports does not readily assist the development of an EMS. The paper finds that the recommendations from an EIA could be structured and summarised to make them more accessible and that certifying the EMS could become a means of ensuring their implementation.
DEVELOPING MUNICIPAL CAPACITY FOR EIA IN SLOVAKIA
Authors: WILSON ELIZABETH , ŠVIHLOVÁ DANA 
Published: May 2003

Effective implementation of environmental policy proves difficult in many countries. Even where there is a comprehensive policy framework, the capacity for implementation at the local level may be weak. In some countries of central and eastern Europe, such as Slovakia, local government has acquired new environmental responsibilities, but lacks the capacity for exercising these roles. The Slovakian environmental impact assessment (EIA) law, for example, gives local government a role as a channel for public comment. However, most municipalities lack the technical expertise or political experience to play an effective role in the EIA process. This paper describes a project supported by the UK Know-How Fund with Slovakian partners to develop municipal capacity. It offers a preliminary evaluation of the effectiveness of the programme, and emphasises the need for training in EIA to relate to municipalities' other environmental responsibilities. It draws some conclusions on cross-national learning between local government in central and western Europe.
Kernel-Based Nonlinear Blind Source Separation
Authors: Harmeling Stefan , Ziehe Andreas , Kawanabe Motoaki , Müller Klaus-Robert 
Published: May 2003

We propose kTDSEP, a kernel-based algorithm for nonlinear blind source separation (BSS). It combines complementary research fields: kernel feature spaces and BSS using temporal information. This yields an efficient algorithm for nonlinear BSS with invertible nonlinearity. Key assumptions are that the kernel feature space is chosen rich enough to approximate the nonlinearity and that signals of interest contain temporal information. Both assumptions are fulfilled for a wide set of real-world applications. The algorithm works as follows: First, the data are (implicitly) mapped to a high (possibly infinite)—dimensional kernel feature space. In practice, however, the data form a smaller submanifold in feature space—even smaller than the number of training data points—a fact that has already been used by, for example, reduced set techniques for support vector machines. We propose to adapt to this effective dimension as a preprocessing step and to construct an orthonormal basis of this submanifold. The latter dimension-reduction step is essential for making the subsequent application of BSS methods computationally and numerically tractable. In the reduced space, we use a BSS algorithm that is based on second-order temporal decorrelation. Finally, we propose a selection procedure to obtain the original sources from the extracted nonlinear components automatically. Experiments demonstrate the excellent performance and efficiency of our kTDSEP algorithm for several problems of nonlinear BSS and for more than two sources.
Auditory cues can modify the gait of persons with early-stage Parkinson's disease: a method for enhancing parkinsonian walking performance?
Authors: Howe T E , Lövgreen B , Cody F WJ , Ashton V J , Oldham J A 
Published: May 2003

Objective: To investigate whether systematically adjusting the rate of auditory cues induces corresponding modulations of the temporal and spatial parameters of gait of patients with early-stage Parkinson's disease. Design: Subjects performed a series of 15 9-metre walks along a level floor under uncued and four cued conditions; the order of cued conditions was randomized. Setting: A physiotherapy gymnasium, Manchester, UK. Subjects: Eleven subjects with early-stage idiopathic Parkinson's disease. Interventions: Preferred pace was established from the initial three uncued walks. The rate of auditory cues delivered throughout subsequent walks was systematically adjusted for each subject, representing 85, 92.5, 107.5 and 115% of their mean cadence at preferred walking pace. Main outcome measures: Mean cadence, mean stride length and mean velocity. Results: Repeated measures ANOVA indicated that the mean velocity and mean cadence of subjects' gait significantly ( p ≤ 0.01) increased relative to baseline values at cue rates of 115 and 107.5% of cadence at preferred pace and decreased at cue rate of 85%. Mean stride length was unaffected by variations in cue rate. Conclusion: The rate of auditory cues, within the range tested, can modulate cadence and thus velocity of gait of subjects with early-stage Parkinson's disease. The provision of auditory cues provides a potential strategy for enhancing walking performance in these patients.
Interpreting change scores on the Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-40)
Authors: Jenkinson C , Peto V , Jones G , Fitzpatrick R 
Published: May 2003

Objectives: To determine the amount of change over time on the five dimensions of the 40-item Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-40) that are subjectively meaningful to patients. Minimally important differences (MID), effect sizes (ES) and standardized response means (SRM) are calculated for respondents who indicate only a little change over the time of the study whilst mean change scores, ES and SRM statistics are calculated for those who indicated much change. Design: Postal survey. Copies of the ALSAQ-40 were completed on two occasions three months apart. Respondents were also asked to indicate how much change they had experienced since baseline on each of the five domains of the questionnaire. Setting: All patient members of the Motor Neurone Disease Association for England, Wales and Northern Ireland. Subjects: Seven hundred and sixty-four patient members returned questionnaires at baseline and follow-up. Results: For those reporting minor change since baseline results varied across dimensions. For example a MID was reflected in a change of 6.67 (SD 16.52) points for the Communication dimension, whilst for the Emotional functioning dimension the change was 2.67 (SD 15.45) points. Similarly ESs and SRMs varied considerably across dimensions. Mean change over time, ES and SRM statistics for those who reported that their health was much worse at follow-up were substantially larger: for example, mean changes ranged from 6.87 (SD 15.87) to 13.79 (SD 22.60). Conclusions: Results indicate the minimum magnitude of change that is subjectively meaningful to patients. Results indicate that smaller changes than have been suggested previously as significant have a subjectively meaningful adverse effect upon patients.