55 research outputs found

    Improved multimedia server I/O subsystems

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    This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.---- Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.The main function of a continuous media server is to concurrently stream data from storage to multiple clients over a network. The resulting streams will congest the host CPU bus, reducing access to the system's main memory, which degrades CPU performance. The purpose of this paper is to investigate ways of improving I/O subsystems of continuous media sewers. Several improved I/O subsystem architectures are presented and their performances evaluated. The proposed architectures use an existing device, namely the Intel i960RP processor. The objective of using an I/O processor is to move the stream and its control from the host processor and the main memory. The ultimate aim is to identify the requirements for an integrated I/O subsystem for a high performance scalable media-on-demand server

    A New Approach for Modeling of a Fluidized Bed by CFD-DEM

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    Numerical studies of 3D cylindrical fluidized bed by means of combined computational fluid dynamics (CFD) and discrete element method (DEM) were carried out. For motion of particles, Newton\u27s second law and 3D compressible Navier-Stokes equations in generalized curvilinear coordinates in its conservative form were used. Navier-Stokes equations were solved with high order compact finite difference scheme by fully implicit flux decomposition method. Non-reflecting boundary conditions (NRBC) were used for the outflow boundary. The convergence of this method, especially at high Reynolds number, is significantly better than the SIMPLE method

    Job Involvement and Organizational Commitment of Employees of Prehospital Emergency Medical System

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    Background: Several studies are available on organizational commitment of employees in different organizations. However, the organizational commitment and job involvement of the employees in the prehospital emergency medical system (PEMS) of Iran have largely been ignored. Objectives: This study aimed to investigate the organizational commitment and job involvement of the employees of PEMS and the relationship between these two issues. Materials and Methods: This cross-sectional study was conducted on 160 employees of Kashan PEMS who were selected through a census method in 2014. A 3-part instrument was used in this study, including a demographic questionnaire, the Allen and Miller’s organizational commitment inventory, and the Lodahl and Kejner’s job involvement inventory. We used descriptive statistics, Spearman correlation coefficient, Kruskal-Wallis, Friedman, analysis of variance, and Tukey post hoc tests to analyze the data. Results: The mean job involvement and organizational commitment scores were 61.78 ± 10.69 and 73.89 ± 13.58, respectively. The mean scores of job involvement and organizational commitment were significantly different in subjects with different work experiences (P = 0.043 and P = 0.012, respectively). However, no significant differences were observed between the mean scores of organizational commitment and job involvement in subjects with different fields of study, different levels of interest in the profession, and various educational levels. A direct significant correlation was found between the total scores of organizational commitment and job involvement of workers in Kashan PEMS (r = 0.910, P < 0.001). Conclusions: This study showed that the employees in the Kashan PEMS obtained half of the score of organizational commitment and about two-thirds of the job involvement score. Therefore, the higher level managers of the emergency medical system are advised to implement some strategies to increase the employees’ job involvement and organizational commitment

    Dynamic Characteristics of Bubbling and Turbulent Fluidization Using Hurst Analysis Technique

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    A non-intrusive vibration monitoring technique was used to study the flow behavior in a fluidized bed. This technique has several advantages compared to other techniques, such as pressure probes and optical fiber probes which may influence the measurement because they are intrusive. Experiments were conducted in a 15 cm diameter by 2 m tall fluidized bed using 470 micron sand particles. Auto correlation functions, mutual information function and Hurst exponent analyses were used to analyze the fluidized bed hydrodynamics near the transition point from bubbling to turbulent fluidization regime. These methods were able to detect the regime transition point using vibration signals

    The Study of the Main Characteristics of Digital Libraries in Iran Part 1: The Situation in 2009

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    The present research endeavors to discover similarities and differences among digital libraries in Iran and to clarify the extent of their consistency in terms of main library requisites. Using a qualitative -quantitative method, i.e. a survey research method using content analysis, it identifies Iranian Digital Libraries (IDLs) and explores their characteristics. Reviewing the literature, we identified the main requisites for libraries including search and browsing facilities, search mode, collection development policies, content, document types, feedback, access models and services and then composed them into a checklist. Searching Google, we verified the top 500 of the records returned to identify IDLs and study them regarding the criteria. The results showed that the IDLs vary strongly in their main traits and library requirements, signifying a general variation in their developers' interpretations of digital library concept. The strong points of the IDLs are their variety in contents, materials and subjects covered as well as in devising browsing facilities, multilingual collections and feedback mechanisms. However, they showed to be deficient in providing a variety of services, search and management mechanisms. The significance of the research relies on the importance of commonly agreed perceptions of digital libraries on their future success. It affects the nature of the relationships between information users, providers and intermediaries as well as their designing, implementation and resource, access and legalmanagement and the services types and extents

    A new approach for modeling of a fluidized bed by CFD-DEM

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    Numerical studies of 3D cylindrical fluidized bed by means of combined computational fluid dynamics (CFD) and discrete element method (DEM) were carried out. For motions of particles, Newton's second law and 3D compressible Navier-Stokes equations in generalized curvilinear coordinates in its conservative form were used. Navier-Stokes equations were solved with this high order compact finite difference scheme by fully implicit flux decomposition methods. Non-reflecting boundary conditions (NRBC) were used for the outflow boundary. The convergence of this method, especially at high Reynolds number, is significantly better than the SIMPLE method

    Genetic and antigenic analysis of type O and A FMD viruses isolated in Iran,

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    ABSTRACT FMD is one of the most highly contagious diseases of animals, caused by RNA virus belong to Picornaviridae family and Aphtovirus genus. A broad host range and occurrence of FMDV as seven serotypes and also intratypic antigenic variation without clear cut demarcations, which interferes with a concept of sub typing these factors make difficult conditions to diagnosis, control and eradication of disease. Therefore it is very important to characterize virus strains and monitoring the field virus to determine the relationship between field viruses and vaccine strains. The objective of this study was to characterize FMD type O, A, virus isolated from Iran between 2005 and 2006. 13 FMD type A and 6 type O viruses isolated from Iran between 2005 and 2006 were used in this study. All viruses adapted to IBRS2 cells and the clarified infected cell culture supernatants were used for typing by sandwich capture ELISA and extraction of viral RNA for RT-PCR reaction with the specific primer for each type. The PCR products were purified for sequencing. Sequence of 600 nucleotides at the 3` end of 1D gene of all samples subjected to phylogenic analysis and determine the antigenic relationship (&quot;r&quot; Value). All type A viruses that isolated from different province of Iran, sequenced in this study, were closely related to each other and A/iran/05 virus group. The sequencing results of type O isolated from Iran between 2005 and 2006 showed the close genetic relationship between field isolates and the Iranian vaccine strain. The result of average &quot;r&quot; Value detected by two dimensional virus neutralization test, for type A87IR was 0.46 (46%), type A05IR 0.78 (78%), type O Shabestar 0.81 (81%) and type O967 0.90 (90%)

    Towards A Molecular Understanding of The Cannabinoid Related Orphan Receptor GPR18: A Focus on Its Constitutive Activity

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    The orphan G-protein coupled receptor (GPCR), GPR18, has been recently proposed as a potential member of the cannabinoid family as it recognizes several endogenous, phytogenic, and synthetic cannabinoids. Potential therapeutic applications for GPR18 include intraocular pressure, metabolic disorders, and cancer. GPR18 has been reported to have high constitutive activity, i.e., activation/signaling occurs in the absence of an agonist. This activity can be reduced significantly by the A3.39N mutation. At the intracellular (IC) ends of (transmembrane helices) TMH3 and TMH6 in GPCRs, typically, a pair of oppositely charged amino acids form a salt bridge called the “ionic lock”. Breaking of this salt bridge creates an IC opening for coupling with G protein. The GPR18 “ionic lock” residues (R3.50/S6.33) can form only a hydrogen bond. In this paper, we test the hypothesis that the high constitutive activity of GPR18 is due to the weakness of its “ionic lock” and that the A3.39N mutation strengthens this lock. To this end, we report molecular dynamics simulations of wild-type (WT) GPR18 and the A3.39N mutant in fully hydrated (POPC) phophatidylcholine lipid bilayers. Results suggest that in the A3.39N mutant, TMH6 rotates and brings R3.50 and S6.33 closer together, thus strengthening the GPR18 “ionic lock”.This research was supported by a grant from the National Institutes on Drug Abuse KO5 DA021358 to PHR.We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)Peer reviewe
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