bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimal Load Balancing on Distributed Homogeneous Unreliable Processors
Authors: Liu Zhen , Righter Rhonda 
Published: November 2008

We consider optimal load balancing in a distributed computing environment consisting of homogeneous unreliable processors. Each processor receives its own sequence of tasks from outside users, some of which can be redirected to the other processors. Processing times are independent and identically distributed with an arbitrary distribution. The arrival sequence of outside tasks to each processor may be arbitrary as long as it is independent of the state of the system. Processors may fail, with arbitrary failure and repair processes that are also independent of the state of the system. The only information available to a processor is the history of its decisions for routing work to other processors, and the arrival times of its own arrival sequence. We prove the optimality of the round-robin policy, in which each processor sends all the tasks that can be redirected to each of the other processors in turn. We show that, among all policies that balance workload, round robin stochastically minimizes the nth task completion time for all n, and minimizes response times and queue lengths in a separable increasing convex sense for the entire system. We also show that if there is a single centralized controller, round-robin is the optimal policy, and a single controller using round-robin routing is better than the optimal distributed system in which each processor routes its own arrivals. Again “optimal” and “better” are in the sense of stochastically minimizing task completion times, and minimizing response time and queue lengths in the separable increasing convex sense.
The Importance of Power-Tail Distributions for Modeling Queueing Systems
Authors: Greiner Michael , Jobmann Manfred , Lipsky Lester 
Published: November 2008

Power-tail distributions are those for which the reliability function is of the form x−α for large x. Although they look well behaved, they have the singular property that E(Xℓ) = ∞ for all ℓ ≥ α. Thus it is possible to have a distribution with an infinite variance, or even an infinite mean. As pathological as these distributions seem to be, they occur everywhere in nature, from the CPU time used by jobs on main-frame computers to sizes of files stored on discs, earthquakes, or even health insurance claims. Recently, traffic on the “electronic super highway” was revealed to be of this type, too. In this paper we first describe these distributions in detail and show their suitability to model self-similar behavior, e.g., of the traffic stated above. Then we show how these distributions can occur in computer system environments and develop a so-called truncated analytical model that in the limit is power-tail. We study and compare the effects on system performance of a GI/M/1 model both for the truncated and the limit case, and demonstrate the usefulness of these approaches particularly for Markov modeling with LAQT (Linear Algebraic Approach to Queueing Theory, Lipsky 1992) techniques.
Simulation Techniques in Operations Research—A Review
Authors: Harling John 
Published: November 2008

The purpose of this paper is to give an introductory account of the techniques of simulation, to present a few of the leading ideas which have been developed, and to draw attention to what is in fact a very open and somewhat ill-defined subject. Considerable confusion exists over the best terminology to use. The term ‘Monte Carlo’ is presently somewhat fashionable, the term ‘simulation’ is to be preferred, because it does not suggest that the technique is limited to what is familiar to statisticians as a sampling experiment. By simulation is meant the technique of setting up a stochastic model of a real situation, and then performing sampling experiments upon the model. The feature which distinguishes a simulation from a mere sampling experiment in the classical sense is that of the stochastic model. Whereas a classical sampling experiment in statistics is most often performed directly upon raw data, a simulation entails first of all the construction of an abstract model of the system to be studied.
Bibliography on the Use of Simulation in Management Analysis
Authors: Malcolm D. G. 
Published: November 2008

Computer simulation, as a problem-solving technique, is now proving to be of increasing value as part of research and design methods directed towards attaining a better understanding and improved control of the operations of complex business and military organization. In system simulation the computer is typically utilized in problem-solving associated with the specific tasks of designing better systems, understanding the workings of operative systems, and studying man-machine interactions. Literature dealing with system simulation is appearing more frequently, but still sporadic enough to warrant the collection here of a number of individual titles that have proved of special interest. This bibliography represents a fair sampling of simulation literature to date. For the convenience of the user, industrial and military applications have been kept separate. Finally, a number of titles on simulation training games and exercises have been included.
Child visual discourse: The use of language, gestures, and vocalizations by deaf preschoolers1
Authors: Tomaszewski Piotr 
Published: November 2008

Child visual discourse: The use of language, gestures, and vocalizations by deaf preschoolers1
This exploratory study examined the linguistic activity and conversational skills of deaf preschoolers by observing child-child dyads in free-play situations. Deaf child of deaf parents - deaf child of deaf parents (DCDP-DCDP) pairs were compared with deaf child of hearing parents - deaf child of hearing parents (DCHP-DCHP) pairs. Children from the two groups were videotaped during dyadic peer interactions in a naturalistic play situation. The findings indicated that deaf children were able to engage in successful communicative interaction. However, statistically significant differences were found between the two groups of deaf preschoolers with regard to some categories of communicative behaviors from the point of view of sign and spoken languages (Polish Sign Language and Polish). For example, DCHP were found to be less actively than DCDP through using speech. The results of this study suggest that intervention efforts should be focused on improving the language learning environment by facilitating signing by the parents and increasing their skills in visual-gestural strategies.
How to estimate the randomness in random sequence generation tasks?
Authors: Barbasz Jakub , Stettner Zbigniew , Wierzchoń Michal , Piotrowski Krzysztof , Barbasz Anna 
Published: November 2008

How to estimate the randomness in random sequence generation tasks?
The aim of the paper was to discuss the accuracy of the multiple indexes used for random sequences generation results calculation. In the first part of the paper the models explaining deviations from randomness were presented. The key role of the structural limitations interpretation was suggested. Secondly, the multiple indexes of the deviation from randomness used in random sequence generation task studies were presented. The authors concluded that too many indexes are used in the studies of deviation from randomness. In order to avoid such problems two indexes were proposed: entropy and correlation function. The last part of the paper presents the preliminary version of the mathematical of random sequences generation in which the limited capacity of the short-term memory assumption was introduce.
Asymmetric potentials and motor effect: a homogenization approach
Authors: Souganidis Panagiotis E. , Perthame Benoît 
Published: November 2008

We provide a mathematical analysis for the appearance of motor effects, i.e., the concentration (as Dirac masses) at one side of the domain, for the solution of a Fokker–Planck system with two components, one with an asymmetric potential and diffusion and one with pure diffusion. The system has been proposed as a model for motor proteins moving along molecular filaments. Its components describe the densities of different conformations of proteins.
Contrary to the case with two asymmetric potentials, the case at hand requires a large number of periods in order for the motor effect to occur. It is therefore posed as a homogenization problem where the diffusion length is at the same scale as the period of the potential.
Our approach is based on the analysis of a Hamilton–Jacobi equation arising, at the zero diffusion limit, after an exponential transformation of the phase functions. The homogenization procedure yields an effective Hamiltonian whose properties are closely related to the concentration phenomena.
Asymmetric post‐natal development of superior cervical ganglion of paca (Agouti paca)
Authors: Abrahão Luciana Maria Bigaram , Nyengaard Jens Randel , Sasahara Tais Harumi de Castro , Gomes Sílvio Pires , Oliveira Felipe da Roza , Ladd Fernando Vagner Lobo , Ladd Aliny Antunes Barbosa Lobo , de Melo Mariana Pereira , Machado Márcia Rita Fernandes , Melo Samanta Rios , Ribeiro Antonio Augusto Coppi Maciel 
Published: November 2008

AbstractFunctional asymmetry has been reported in sympathetic ganglia. Although there are few studies reporting on body side‐related morphoquantitative changes in sympathetic ganglion neurons, none of them have used design‐based stereological methods to address this issue during post‐natal development. We therefore aimed at detecting possible asymmetry‐related effects on the quantitative structure of the superior cervical ganglion (SCG) from pacas during ageing, using very precise design‐based stereological methods. Forty (twenty left and twenty right) SCG from twenty male pacas were studied at four different ages, i.e. newborn, young, adult and aged animals. By using design‐based stereological methods the total volume of ganglion and the total number of mononucleate and binucleate neurons were estimated. Furthermore, the mean perikaryal volume of mononucleate and binucleate neurons was estimated, using the vertical nucleator. The main findings of this study were: (1) the right SCG from aged pacas has more mononucleate and binucleate neurons than the left SCG in all other combinations of body side and animal age, showing the effect of the interaction between asymmetry (right side) and animal age, and (2) right SCG neurons (mono and binucleate) are bigger than the left SCG neurons (mono and binucleate), irrespective of the animal age. This shows, therefore, the exclusive effect of asymmetry (right side). At the time of writing there is still no conclusive explanation for some SCG quantitative changes exclusively assigned to asymmetry (right side) and those assigned to the interaction between asymmetry (right side) and senescence in pacas. We therefore suggest that forthcoming studies should focus on the functional consequences of SCG structural asymmetry during post‐natal development. Another interesting investigation would be to examine the interaction between ganglia and their innervation targets using anterograde and retrograde neurotracers. Would differences in the size of target organs explain ganglia structural asymmetry?
Direct numerical simulation of the Ekman layer: A step in Reynolds number, and cautious support for a log law with a shifted origin
Authors: Spalart Philippe R. , Coleman Gary N. , Johnstone Roderick 
Published: November 2008

Results at Ekman Reynolds numbers Re ranging from 1000 to 2828 expand the direct numerical simulation (DNS) contribution to the theory of wall-bounded turbulence. An established spectral method is used, with rules for domain size and grid resolution at each Reynolds number derived from the theory. The Re increase is made possible by better computers and by optimizing the grid in relation to the wall shear-stress direction. The boundary-layer thickness in wall units δ+ varies here by a factor of about 5.3, and reaches values near 5000, or 22 times the minimum at which turbulence has been sustained. An equivalent channel Reynolds number, based on the pressure gradient in wall units, would reach about Reτ=1250. The principal goal of the analysis, the impartial identification of a log law, is summarized in the local “Karman measure” d(ln z+)/dU+. The outcome differs from that for Hoyas and Jiménez [Phys. Fluids18, 011702 (2006)] and for Hu [AIAA J.44, 1541 (2006)] in channel-flow DNS at similar Reynolds numbers, for reasons unknown: Here, the law of the wall is gradually established up to a z+ around 400, with little statistical scatter. To leading order, it is consistent with the experiments of Österlund [Phys. Fluids12, 1 (2000)] in boundary layers. With the traditional expression, a logarithmic law is not present, in that the Karman measure drifts from about 0.41 at z+≈70 to the 0.37–0.38 range for z+≈500, with Re=2828. However, if a virtual origin is introduced with a shift of a+=7.5 wall units, the data support a long logarithmic layer with κ=0.38 a good fit to d(ln[z++a+])/dU+. A determination of the Karman constant from the variation of the skin-friction coefficients with Reynolds numbers also yields values near 0.38. The uncertainty is about ±0.01. These values are close to the boundary-layer experiments, but well below the accepted range of [0.40,0.41] and the experimental pipe-flow results near 0.42. The virtual-origin concept is also controversial, although nonessential at transportation or atmospheric Reynolds numbers. Yet, this series may reflect some success in verifying the law of the wall and investigating the logarithmic law by DNS, redundantly and with tools more impartial than the visual fit of a straight line to a velocity profile.
At the request of the authors and editor, this article is being retracted effective 28 October 2009.
Human genomes as email attachments
Authors: Christley Scott , Lu Yiming , Li Chen , Xie Xiaohui 
Published: November 2008

Abstract
Summary: The amount of genomic sequence data being generated and made available through public databases continues to increase at an ever-expanding rate. Downloading, copying, sharing and manipulating these large datasets are becoming difficult and time consuming for researchers. We need to consider using advanced compression techniques as part of a standard data format for genomic data. The inherent structure of genome data allows for more efficient lossless compression than can be obtained through the use of generic compression programs. We apply a series of techniques to James Watson's genome that in combination reduce it to a mere 4MB, small enough to be sent as an email attachment.
Availability: Our algorithms are implemented in C++ and are freely available from http://www.ics.uci.edu/~xhx/project/DNAzip.
Contact: chenli@ics.uci.edu; xhx@ics.uci.edu
Supplementary information: Supplementary data are available at Bioinformatics online.
Are We Ready and How Do We Know? The Urgent Need for Performance Metrics in Hospital Emergency Management
Authors: Lazar Eliot J. , Cagliuso Nicholas V. , Gebbie Kristine M. 
Published: November 2008

ABSTRACTAn extraordinary number of health care quality and patient safety indicators have been developed for hospitals and other health care institutions; however, few meaningful indicators exist for comprehensive assessment of hospital emergency management. Although health care institutions have invested considerable resources in emergency management preparedness, the need for universally accepted, evidence-based performance metrics to measure these efforts remains largely unfulfilled. We suggest that this can be remediated through the application of traditional health care quality paradigms, coupled with novel analytic approaches to develop meaningful performance data in hospital emergency management. (Disaster Med Public Health Preparedness. 2009;3:57–60)
Divergent Regulation of Terpenoid Metabolism in the Trichomes of Wild and Cultivated Tomato Species
Authors: Besser Katrin , Harper Andrea , Welsby Nicholas , Schauvinhold Ines , Slocombe Stephen , Li Yi , Dixon Richard A. , Broun Pierre 
Published: November 2008

AbstractThe diversification of chemical production in glandular trichomes is important in the development of resistance against pathogens and pests in two species of tomato. We have used genetic and genomic approaches to uncover some of the biochemical and molecular mechanisms that underlie the divergence in trichome metabolism between the wild species Solanum habrochaites LA1777 and its cultivated relative, Solanum lycopersicum. LA1777 produces high amounts of insecticidal sesquiterpene carboxylic acids (SCAs), whereas cultivated tomatoes lack SCAs and are more susceptible to pests. We show that trichomes of the two species have nearly opposite terpenoid profiles, consisting mainly of monoterpenes and low levels of sesquiterpenes in S. lycopersicum and mainly of SCAs and very low monoterpene levels in LA1777. The accumulation patterns of these terpenoids are different during development, in contrast to the developmental expression profiles of terpenoid pathway genes, which are similar in the two species, but they do not correlate in either case with terpenoid accumulation. However, our data suggest that the accumulation of monoterpenes in S. lycopersicum and major sesquiterpenes in LA1777 are linked both genetically and biochemically. Metabolite analyses after targeted gene silencing, inhibitor treatments, and precursor feeding all show that sesquiterpene biosynthesis relies mainly on products from the plastidic 2-C-methyl-d-erythritol-4-phosphate pathway in LA1777 but less so in the cultivated species. Furthermore, two classes of sesquiterpenes produced by the wild species may be synthesized from distinct pools of precursors via cytosolic and plastidial cyclases. However, highly trichome-expressed sesquiterpene cyclase-like enzymes were ruled out as being involved in the production of major LA1777 sesquiterpenes.
Genome-Wide Analysis of MIKCC-Type MADS Box Genes in Grapevine
Authors: Díaz-Riquelme José , Lijavetzky Diego , Martínez-Zapater José M. , Carmona María José 
Published: November 2008

AbstractMIKCC-type MADS box genes encode transcription factors that play crucial roles in plant growth and development. Analysis of the grapevine (Vitis vinifera) genome revealed up to 38 MIKCC-type genes. We report here a complete analysis of this gene family regarding their phylogenetic relationships with homologous genes identified in other sequenced dicot genomes, their genome location, and gene structure and expression. The grapevine genes cluster in 13 subfamilies with their Arabidopsis (Arabidopsis thaliana) and poplar (Populus trichocarpa) counterparts. The lack of recent whole genome duplications in grapevine allows assigning the gene diversification processes observed within each subfamily either to an ancestral polyploidization event predating the divergence of those three species or to later duplication events within each lineage. Expression profiles of MIKCC-type genes in vegetative and reproductive organs as well as during flower and tendril development show conserved expression domains for specific subfamilies but also reflect characteristic features of grapevine development. Expression analyses in latent buds and during flower development reveal common features previously described in other plant systems as well as possible new roles for members of some subfamilies during flowering transition. The analysis of MIKCC-type genes in grapevine helps in understanding the origin of gene diversification within each subfamily and provides the basis for functional analyses to uncover the role of these MADS box genes in grapevine development.
A Heterocomplex of Iron Superoxide Dismutases Defends Chloroplast Nucleoids against Oxidative Stress and Is Essential for Chloroplast Development inArabidopsis
Authors: Myouga Fumiyoshi , Hosoda Chieko , Umezawa Taishi , Iizumi Haruko , Kuromori Takashi , Motohashi Reiko , Shono Yuriko , Nagata Noriko , Ikeuchi Masahiko , Shinozaki Kazuo 
Published: November 2008

AbstractThere are three iron superoxide dismutases in Arabidopsis thaliana: FE SUPEROXIDE DISMUTASE1 (FSD1), FSD2, and FSD3. Their biological roles in chloroplast development are unknown. Here, we show that FSD2 and FSD3 play essential roles in early chloroplast development, whereas FSD1, which is found in the cytoplasm, does not. An fsd2-1 fsd3-1 double mutant had a severe albino phenotype on agar plates, whereas fsd2 and fsd3 single knockout mutants had pale green phenotypes. Chloroplast development was arrested in young seedlings of the double mutant. The mutant plants were highly sensitive to oxidative stress and developed increased levels of reactive oxygen species (ROS) during extended darkness. The FSD2 and FSD3 proteins formed a heteromeric protein complex in the chloroplast nucleoids. Furthermore, transgenic Arabidopsis plants overexpressing both the FSD2 and FSD3 genes showed greater tolerance to oxidative stress induced by methyl viologen than did the wild type or single FSD2- or FSD3-overexpressing lines. We propose that heteromeric FSD2 and FSD3 act as ROS scavengers in the maintenance of early chloroplast development by protecting the chloroplast nucleoids from ROS.
Perceptions of foreign players for effective positioning in India
Authors: Sharma Somesh Kumar , Srinivasan R. 
Published: November 2008

PurposeThe purpose of this paper is to identify facts of effective positioning mechanism for Indian market and develop a model that integrates three essential aspects of international trade, which have not been addressed combined yet.Design/methodology/approachThe article develops the information framework for Indian market positioning. The information mentioned in the framework is validated using statistical tools with R Software and refined using Principal Component Analysis and Factor Analysis. The outcome of analysis develops the model for effective positioning mechanism for Indian market.FindingsThe study explores three statistically significant steps for effective Indian market positioning, which are finally summarized into 18 influencing variables in contrast to 91 variables available in literature.Research implicationsThe 18 variables explored in this study should be considered as initial set of information, only for Indian market positioning. It should not be taken as standard paradigm to be followed in all cases. Research needs to be made to valuate such implications.Practical implicationsThe model developed in this paper will be useful to both mature and ambitious international executives, in identifying the variables that can be considered for strategy formulation at different stages of Indian market positioning process.Originality/valueThis article offers a model that addresses research on Indian market positioning. It attempts to establish a relationship among the three components of international business, which can bring potential benefits to the foreign players.