bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Perl Commodity Grid Toolkit
Authors: Mock Stephen , Thomas Mary , Dahan Maytal , Mueller Kurt , Mills Catherine , von Lazewski Gregor 
Published: January 2003

AbstractThe Perl Commodity Grid Toolkit (Perl CoG Kit) is a software project aimed at bringing the complexities and power of the computational Grid to developers of Perl applications. In this paper we describe the history and motivation of the project, the benefits of bringing the Grid to Perl developers, the architecture and status of the Perl CoG Kit and the future plans for the project. Copyright © 2002 John Wiley & Sons, Ltd.
The Virtual Laboratory: a toolset to enable distributed molecular modelling for drug design on the World‐Wide Grid
Authors: Buyya Rajkumar , Branson Kim , Giddy Jon , Abramson David 
Published: January 2003

AbstractComputational Grids are emerging as a new paradigm for sharing and aggregation of geographically distributed resources for solving large‐scale compute and data intensive problems in science, engineering and commerce. However, application development, resource management and scheduling in these environments is a complex undertaking. In this paper, we illustrate the development of a Virtual Laboratory environment by leveraging existing Grid technologies to enable molecular modelling for drug design on geographically distributed resources. It involves screening millions of compounds in the chemical database (CDB) against a protein target to identify those with potential use for drug design. We have used the Nimrod‐G parameter specification language to transform the existing molecular docking application into a parameter sweep application for executing on distributed systems. We have developed new tools for enabling access to ligand records/molecules in the CDB from remote resources. The Nimrod‐G resource broker along with molecule CDB data broker is used for scheduling and on‐demand processing of docking jobs on the World‐Wide Grid (WWG) resources. The results demonstrate the ease of use and power of the Nimrod‐G and virtual laboratory tools for grid computing. Copyright © 2003 John Wiley & Sons, Ltd.
A stochastic load balancing algorithm for i‐Computing
Authors: Wong Yuk‐Yin , Leung Kwong‐Sak , Lee Kin‐Hong 
Published: January 2003

AbstractThis paper presents a stochastic dynamic load balancing algorithm for Internet computing, which is a new type of distributed computing involving heterogeneous workstations from different organizations on the Internet. To realize the practical environment, we assume the system to be comprised of heterogeneous, untrusted and non‐dedicated workstations connected by a non‐dedicated network. Our algorithm uses the product of the average processing time and the queue length of system jobs as the load index. Dynamic communication delay is included in the execution cost calculation. The transfer policy and the location policy are combined in a stochastic algorithm. State information exchange is done via information feedback and mutual updating. Simulations demonstrate that our algorithm outperforms conventional approaches over a wide range of system parameters. These results are reconfirmed by empirical experiments after we have implemented the algorithms on the Distributed Java Machine global virtual machine. Copyright © 2003 John Wiley & Sons, Ltd.
Clustering revealed in high‐resolution simulations and visualization of multi‐resolution features in fluid–particle models
Authors: Boryczko Krzysztof , Dzwinel Witold , Yuen David A. 
Published: January 2003

AbstractSimulating natural phenomena at greater accuracy results in an explosive growth of data. Large‐scale simulations with particles currently involve ensembles consisting of between 106 and 109 particles, which cover 105–106 time steps. Thus, the data files produced in a single run can reach from tens of gigabytes to hundreds of terabytes. This data bank allows one to reconstruct the spatio‐temporal evolution of both the particle system as a whole and each particle separately. Realistically, for one to look at a large data set at full resolution at all times is not possible and, in fact, not necessary. We have developed an agglomerative clustering technique, based on the concept of a mutual nearest neighbor (MNN). This procedure can be easily adapted for efficient visualization of extremely large data sets from simulations with particles at various resolution levels. We present the parallel algorithm for MNN clustering and its timings on the IBM SP and SGI/Origin 3800 multiprocessor systems for up to 16 million fluid particles. The high efficiency obtained is mainly due to the similarity in the algorithmic structure of MNN clustering and particle methods. We show various examples drawn from MNN applications in visualization and analysis of the order of a few hundred gigabytes of data from discrete particle simulations, using dissipative particle dynamics and fluid particle models. Because data clustering is the first step in this concept extraction procedure, we may employ this clustering procedure to many other fields such as data mining, earthquake events and stellar populations in nebula clusters. Copyright © 2003 John Wiley & Sons, Ltd.
Modular specification of frame properties in JML
Authors: Müller Peter , Poetzsch‐Heffter Arnd , Leavens Gary T. 
Published: January 2003

AbstractWe present a modular specification technique for frame properties. The technique uses modifies clauses and abstract fields with declared dependencies. Modularity is guaranteed by a programming model that enforces data abstraction by preventing representation and argument exposure, a semantics of modifies clauses that uses a notion of ‘relevant location’, and by modularity rules for dependencies. For concreteness, we adapt this technique to the Java Modeling Language, JML. Copyright © 2003 John Wiley & Sons, Ltd.
Estimation of token bucket parameters for aggregated VoIP sources
Authors: Garroppo Rosario G. , Giordano Stefano , Pagano Michele 
Published: January 2003

AbstractThe paper presents an analytical study aimed to establish a dimensioning procedure for the token bucket algorithm, used as a meter in a Differentiated Services network architecture, when a stochastic model for the multiplexed traffic is available. In the work, we propose an equivalent queueing system method to ‘on line’ estimate the linear bounded arrival processes (LBAP) parameters when a non‐zero probability of non‐conforming packets is accepted. Then, we validate our approach considering an aggregation of fluidic On‐Off processes with exponentially distributed sojourn time in each state, used to model telephone sources with voice activity detection (VAD). To test the goodness of our analytical results, we employ discrete event simulations, which have highlighted the accuracy of the proposed dimensioning procedure in a voice over IP (VoIP) scenario. Moreover, we investigate the multiplexing gain and the effect of different parameters on the LBAP characterization of the VoIP traffic, taking into account a non‐zero probability of non‐conforming packets. Copyright © 2002 John Wiley & Sons, Ltd.
Erlang capacity analysis of hybrid FDMA/CDMA systems supporting multi‐class services according to channel assignment methods
Authors: Koo Insoo , Yang Jeongrok , Ahmad Aftab , Kim Kiseon 
Published: January 2003

AbstractIn this paper, we focus on the evaluation of the Erlang capacity for hybrid FDMA/CDMA systems supporting multi‐class services with two channel allocation schemes: independent carrier channel assignment (ICCA) and combined carrier channel assignment (CCCA). For the performance analysis, a multi‐dimensional Markov chain model is developed. The effect of the number of carriers of hybrid FDMA/CDMA system on the Erlang capacity is observed, and the optimum values of the system parameters such as the number of channel elements (CEs) and the number of carriers are selected with respect to the Erlang capacity. As a numerical example, we consider an FDMA/CDMA system supporting voice/data services. We find out that, even though the benefit of CCCA scheme over ICCA scheme is negligible for small number of CEs, the scenario changes significantly when the number of CEs increases beyond a certain point. An improvement of as much as 74% can be achieved in the Erlang capacity when 5 carriers are employed. We also find the capacity knees for different number of carriers. The results of this paper could be helpful in the traffic engineering of FDMA/CDMA systems providing multi‐class services. Copyright © 2002 John Wiley & Sons, Ltd.
An Internet friendly transport protocol for continuous media over best effort networks
Authors: ElAarag Hala , Bassiouni Mostafa 
Published: January 2003

AbstractIn this paper, we design and evaluate an Internet friendly transport‐level protocol (IFTP) for solving the TCP‐friendly problem. IFTP has two modes of operation. In the standard mode, the IFTP connection faithfully emulates the behaviour of TCP in order to roughly obtain a bandwidth equal to that of a TCP connection. In the extended mode, a simple modification is used to grant QoS‐differentiated services to selected connections. Connections running in the extended mode can get enhanced bandwidth while still emulating the general behaviour of TCP. We develop an analytical model for the congestion control mechanism of IFTP. We also derive analytically the amount of bandwidth that IFTP may be able to claim from TCP in ideal and non‐ideal environments. We evaluate IFTP through simulation and prove its TCP friendliness as well as provide performance results on some of the important metrics such as packet delay, delay jitter, packet loss and link utilization. Copyright © 2002 John Wiley & Sons, Ltd.
Low pass filter/over drop avoidance (LPF/ODA): an algorithm to improve the response time of RED gateways
Authors: Zheng Bing , Atiquzzaman Mohammed 
Published: January 2003

AbstractThe low pass filter (LPF) algorithm, which is used to calculate the average queue length in the random early detection (RED) algorithm, results in a poor response time when RED recovers from congestion. In this paper, we propose a new algorithm, called low pass filter/over drop avoidance (LPF/ODA), to improve the response time of RED. LPF/ODA is based on reducing the time required by RED to recover from long‐term congestion. Simulation results have been used to show that the proposed LPF/ODA algorithm significantly improves the response time, throughput and delay of RED gateways. Copyright © 2002 John Wiley & Sons, Ltd.
Using TCP rate control for queue input‐output rate matching
Authors: Aweya James , Ouellette Michel , Montuno Delfin Y. 
Published: January 2003

AbstractIn explicit TCP rate control, the receiver's advertised window size in acknowledgment (ACK) packets can be modified by intermediate network elements to reflect network congestion conditions. The TCP receiver's advertised window (i.e. the receive buffer of a TCP connection) limits the maximum window and consequently the throughput that can be achieved by the sender. Appropriate reduction of the advertised window can control the number of packets allowed to be sent from a TCP source. This paper evaluates the performance of a TCP rate control scheme in which the receiver's advertised window size in ACK packets are modified in a network node in order to match the generated load to the assigned bandwidth in the node. Using simulation and performance metrics such as the packet loss rates and the cumulative number of TCP timeouts, we examine the service improvement provided by the TCP rate control scheme to the users. The modified advertised windows computed in the network elements and the link utilization are also examined. Copyright © 2002 John Wiley & Sons, Ltd.
Computer visualization and participatory ergonomics as methods in workplace design
Authors: Sundin A. , Medbo L. 
Published: January 2003

AbstractThis case study was carried out at a Volvo plant in Sweden where manual material handling was done in the form of kitting materials for manual assembly workstations. Due to inefficiency as well as ergonomics factors, the management planned a redesign of the kitting area. A group of workers and researchers was formed and a participatory ergonomic approach was used in which 3D CAD visualization presented solutions. Production and mechanical exposure data were used as input to the group. The results showed that the use of computerized visualization was successful in improving participatory ergonomic work. However, characteristics of visualization software, for example, including animation and manikins, seem to be important for reaching improvements. © 2003 Wiley Periodicals, Inc. Hum Factors Man 13: 1–17, 2003.
An integrated methodology for manufacturing systems design using manual and computer simulation
Authors: Paquet Victor , Lin Li 
Published: January 2003

AbstractTraditional approaches to manufacturing systems design utilize a sequential procedure that focuses on production capacity requirements, with human operator task design developed late in the systems design phase. Implementing manufacturing systems in this way is difficult when operations management must design flexible and efficient processes, with an often incomplete understanding of how people can best perform within the system. This study developed an integrated methodology that uses both manual and computer simulations to evaluate system performance and ergonomic issues early in the system design process. Information about operator performance and ergonomics is obtained in the manual simulations, while estimates of operator utilization and system throughput is obtained through computer simulations. An iterative design process is used, with the results of manual and computer simulations informing each other during subsequent simulations. An industrial case study is presented here to demonstrate the effectiveness of this methodology. The results show that the methodology can be used to design manufacturing systems with significant savings in labor cost and improved manufacturing system flexibility. © 2003 Wiley Periodicals, Inc. Hum Factors Man 13: 19–40, 2003.
Ergonomic weighted scores to evaluate critical instructions for improvements in a printed circuit assembly factory
Authors: Sen Rabindra Nath , Yeow Paul H.P. 
Published: January 2003

AbstractA survey was conducted on the efficacy of the Printed Circuit Assembly operations using newly designed Ergonomic Weighted Scores (EWSs) to evaluate Critical Instructions (CIs) to operators. This helped to choose priorities of problematic operations. Five EWSs were drafted, tried, and finalized by a team of experts, for the purpose of checking the adherence to CIs, failing any of which could cause adverse effects on the quality of products. The top three priority operations were identified and the follow‐up studies resulted in an increase in monthly revenue of US$227,880 and improvements in quality, productivity, occupational health and safety of the operators. © 2003 Wiley Periodicals, Inc. Hum Factors Man 13: 41–58, 2003.
Tolerogenic dendritic cells induced by vitamin D receptor ligands enhance regulatory T cells inhibiting allograft rejection and autoimmune diseases
Authors: Adorini Luciano , Penna Giuseppe , Giarratana Nadia , Uskokovic Milan 
Published: January 2003

AbstractDendritic cells (DCs) not only induce but also modulate T cell activation. 1,25‐dihydroxyvitamin D3[1,25(OH)2D3] induces DCs with a tolerogenic phenotype, characterized by decreased expression of CD40, CD80, and CD86 costimulatory molecules, low IL‐12 and enhanced IL‐10 secretion. We have found that a short treatment with 1,25(OH)2D3induces tolerance to fully mismatched mouse islet allografts that is stable to challenge with donor‐type spleen cells and allows acceptance of donor‐type vascularized heart grafts. This effect is enhanced by co‐administration of mycophenolate mofetil (MMF), a selective inhibitor of T and B cell proliferation that has also effects similar to 1,25(OH)2D3on DCs. Graft acceptance is associated with an increased percentage of CD4+CD25+regulatory cells in the spleen and in the draining lymph node that can protect 100% of syngeneic recipients from islet allograft rejection. CD4+CD25+cells, able to inhibit the T cell response to a pancreatic autoantigen and to significantly delay disease transfer by pathogenic CD4+CD25−cells, are also induced by treatment of adult nonobese diabetic (NOD) mice with 1,25‐dihydroxy‐16,23Z‐diene‐26,27‐hexafluoro‐19‐nor vitamin D3(BXL‐698). This treatment arrests progression of insulitis and Th1 cell infiltration, and inhibits diabetes development at non‐hypercalcemic doses. The enhancement of CD4+CD25+regulatory T cells, able to mediate transplantation tolerance and to arrest type 1 diabetes development by a short oral treatment with VDR ligands, suggests possible clinical applications of this approach. J. Cell. Biochem. 88: 227–233, 2003. © 2002 Wiley‐Liss, Inc.
Regulation of 25‐hydroxyvitamin D3‐24‐hydroxylase mRNA by 1,25‐dihydroxyvitamin D3 and parathyroid hormone
Authors: Zierold Claudia , Mings Jamie A. , DeLuca Hector F. 
Published: January 2003

AbstractThe 25‐hydroxyvitamin D3‐24‐hydroxylase mRNA is tightly and reciprocally regulated by 1,25‐dihydroxyvitamin D3 (1,25(OH)2D3) and parathyroid hormone (PTH). The upregulation of the 24‐hydroxylase by 1,25(OH)2D3 is well established and occurs at the transcriptional level through two vitamin D response elements in the promoter of the gene. However, this induction is blocked by the protein synthesis inhibitor cycloheximide (CHX) indicating a protein component in the regulation pathway. CHX treatment reduced total vitamin D receptor (VDR) protein levels in cells, but reintroduction of VDR and/or retinoid X receptor protein into cells by transfection did not reduce the inhibition by CHX. This indicates that production of another transcription factor or mRNA‐stabilizing protein synthesized in response to 1,25(OH)2D3 is required for optimal accumulation of 24‐hydroxylase mRNA. PTH downregulates the 24‐hydroxylase mRNA by affecting its stability. The half‐life of 24‐hydroxylase mRNA is reduced 4.2‐fold in AOK‐B50 cells by PTH. Untranslated regions of the 24‐hydroxylase mRNA in reporter gene assays did not confer PTH responsiveness. Further analysis of the coding region of the rat 24‐hydroxylase may reveal sites of action of PTH. J. Cell. Biochem. 88: 234–237, 2003. © 2002 Wiley‐Liss, Inc.
Evidence for tissue‐ and cell‐type selective activation of the vitamin D receptor by Ro‐26‐9228, a noncalcemic analog of vitamin D3
Authors: Peleg Sara , Ismail Ayesha , Uskokovic Milan R. , Avnur Zafrira 
Published: January 2003

AbstractOur recent studies have shown that the vitamin D analog Ro‐26‐9228 restores bone mineral density without inducing hypercalcemia in osteopenic rats. Our ex vivo experiments demonstrated that the analog upregulated gene expression in trabecular bone but not in the duodenum of female rats. We examined the mechanism for the tissue selectivity of Ro‐26‐9228 in Caco‐2, a human cell line of intestinal origin, and hFOB, and a human fetal osteoblast cell line. We found that the abilities of Ro‐26‐9228 and the natural hormone, 1,25‐dihydroxyvitamin D3 (1,25D3) to induce VDRE‐reporter gene expression in transiently transfected human osteoblasts are similar. In contrast, in Caco‐2 cells, Ro‐26‐9228 induces 40‐fold less reporter gene expression than 1,25D3 does. We also examined the abilities of the vitamin D receptor (VDR)‐ligand complexes from these two cell lines to interact with partners of transcription (glucocorticoid receptor‐interacting protein, VDR‐interacting protein, and retinoid X receptor), in pull‐down assays. These assays revealed that 1,25D3 induces similar levels of interaction of these co‐factors with VDR from both osteoblasts and intestinal cells. In contrast, Ro‐26‐9228 induces significant interaction of VDR from osteoblast cells with these co‐factors, but less of VDR from Caco‐2 cells. These results suggest that the cellular environment of intestinal cells, unlike that of osteoblasts, represses the ability of VDR‐Ro‐26‐9228 complexes to interact with transcription partners. J. Cell. Biochem. 88: 267–273, 2003. © 2002 Wiley‐Liss, Inc.
Role of the vitamin D‐endocrine system in the pathophysiology of postmenopausal osteoporosis
Authors: Riggs B. Lawrence 
Published: January 2003

AbstractImpaired calcium absorption and impaired adaptation to a low calcium diet are common features of aging in women and these processes are even more severely impaired in patients with osteoporotic fractures. The calcium absorption defects are associated with several abnormalities of the vitamin D‐endocrine system including secondary hyperparathyroidism, intestinal resistance to 1,25‐dihydroxyvitamin D (1,25(OH)2D) action, decreased 1,25(OH)2D production due to impaired 25(OH)D 1α‐hydroxylase activity, and, in some elderly persons, nutritional deficiency of vitamin D. However, in postmenopausal women, most of these abnormalities are normalized by administration of physiologic replacement dosages of estrogen and, thus, appear to be secondary consequences of estrogen deficiency. Nonetheless, a minority of them, especially nutritional vitamin D deficiency and impaired 25(OH)D 1α‐hydroxylase activity late in life, appear to be primary and are independent of estrogen deficiency. J. Cell. Biochem. 88: 209–215, 2003. © 2002 Wiley‐Liss, Inc.
Vitamin D target proteins: Function and regulation
Authors: Christakos S. , Barletta F. , Huening M. , Dhawan P. , Liu Y. , Porta A. , Peng X. 
Published: January 2003

AbstractRecent findings have indicated that calbindin‐D28k, the first known target of vitamin D action, is present in osteoblasts and protects against TNF and glucocorticoid induced apoptosis of osteoblastic cells. Cytokine mediated destruction of pancreatic β cells, a cause of insulin dependent diabetes, is also inhibited by calbindin‐D28k. In calbindin‐D28k transfected pancreatic β cells free radical formation by cytokines is inhibited by calbindin. Thus, besides its role as a facilitator of calcium diffusion, calbindin has a major role in protecting against cellular degeneration in different cell types. Besides calbindin, the other known pronounced effect of 1,25(OH)2D3 in intestine and kidney is increased synthesis of 25(OH)D3 24‐hydroxylase (24(OH)ase) which is involved in the catabolism of 1,25(OH)2D3. We have noted that CCAAT enhancer binding protein β (C/EBPβ) is induced by 1,25(OH)2D3 in kidney and osteoblastic cells and can enhance the transcriptional response of 24(OH)ase to 1,25(OH)2D3. These studies establish C/EBPβ as a novel 1,25(OH)2D3 target gene and indicate a role for C/EBPβ in 24(OH)ase transcription. These studies extend our previous studies related to factors that affect vitamin D receptor (VDR) mediated 24(OH)ase transcription (YY1, TFIIB, CBP) and the effect of signaling pathways on 24(OH)ase transcription and cofactor recruitment. J. Cell. Biochem. 88: 238–244, 2003. © 2002 Wiley‐Liss, Inc.
Regulation of imprinting: A multi‐tiered process
Authors: Rand Eyal , Cedar Howard 
Published: January 2003

AbstractAlthough most mammalian genes are expressed from both alleles, there is a small group of special genes which are imprinted so that only one of the parental alleles is actually expressed in target cells. This epigenetic process involves regulation at a number of different stages of development and is very complex. In principle, imprinted gene regions must be marked in cis in the gametes using epigenetic features capable of being maintained through cell division and able to direct multigenic monoallelic expression in differentiated cells of the mature organism. The difference between alleles must be erased during early gametogenesis to allow the imprint to be reset in the mature gametes. In this review we will summarize what is currently known about the molecular mechanisms which mediate these steps. J. Cell. Biochem. 88: 400–407, 2003. © 2002 Wiley‐Liss, Inc.