The research and development of ChemGrid in CGSP

With the rapid development of computing technologies and network technologies, Grid technology has emerged as the solution for high-performance computing. Recently, the grid of orient-services has become a hot issue in this research area. In this paper, we propose an architecture of ChemGrid in CGSP (China Grid Support Platform). The effectiveness of the proposed architecture is demonstrated by an example which is developed as a Web service based on CGSP; the Web service is used for searching elements in the periodic table. An improvement of the user interface for applications is proposed in order to obtain results interactively. Finally, an extension of ChemGrid is discussed in order to integrate different types of resources and provide specialized services.<br /

Regionally distributed architecture for dynamic e-learning environment (RDADeLE)

e-Learning is becoming an influential role as an economic method and a flexible mode of study in the institutions of higher education today which has a presence in an increasing number of college and university courses. e-Learning as system of systems is a dynamic and scalable environment. Within this environment, e-learning is still searching for a permanent, comfortable and serviceable position that is to be controlled, managed, flexible, accessible and continually up-to-date with the wider university structure. As most academic and business institutions and training centres around the world have adopted the e-learning concept and technology in order to create, deliver and manage their learning materials through the web, it has become the focus of investigation. However, management, monitoring and collaboration between these institutions and centres are limited. Existing technologies such as grid, web services and agents are promising better results. In this research a new architecture has been developed and adopted to make the e-learning environment more dynamic and scalable by dividing it into regional data grids which are managed and monitored by agents. Multi-agent technology has been applied to integrate each regional data grid with others in order to produce an architecture which is more scalable, reliable, and efficient. The result we refer to as Regionally Distributed Architecture for Dynamic e-Learning Environment (RDADeLE). Our RDADeLE architecture is an agent-based grid environment which is composed of components such as learners, staff, nodes, regional grids, grid services and Learning Objects (LOs). These components are built and organised as a multi-agent system (MAS) using the Java Agent Development (JADE) platform. The main role of the agents in our architecture is to control and monitor grid components in order to build an adaptable, extensible, and flexible grid-based e-learning system. Two techniques have been developed and adopted in the architecture to build LOs' information and grid services. The first technique is the XML-based Registries Technique (XRT). In this technique LOs' information is built using XML registries to be discovered by the learners. The registries are written in Dublin Core Metadata Initiative (DCMI) format. The second technique is the Registered-based Services Technique (RST). In this technique the services are grid services which are built using agents. The services are registered with the Directory Facilitator (DF) of a JADE platform in order to be discovered by all other components. All components of the RDADeLE system, including grid service, are built as a multi-agent system (MAS). Each regional grid in the first technique has only its own registry, whereas in the second technique the grid services of all regional grids have to be registered with the DF. We have evaluated the RDADeLE system guided by both techniques by building a simulation of the prototype. The prototype has a main interface which consists of the name of the system (RDADeLE) and a specification table which includes Number of Regional Grids, Number of Nodes, Maximum Number of Learners connected to each node, and Number of Grid Services to be filled by the administrator of the RDADeLE system in order to create the prototype. Using the RST technique shows that the RDADeLE system can be built with more regional grids with less memory consumption. Moreover, using the RST technique shows that more grid services can be registered in the RDADeLE system with a lower average search time and the search performance is increased compared with the XRT technique. Finally, using one or both techniques, the XRT or the RST, in the prototype does not affect the reliability of the RDADeLE system.Royal Commission for Jubail and Yanbu - Directorate General For Jubail Project Kingdom of Saudi Arabi

Compiler techniques for scalable performance of stream programs on multicore architectures

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 211-222).Given the ubiquity of multicore processors, there is an acute need to enable the development of scalable parallel applications without unduly burdening programmers. Currently, programmers are asked not only to explicitly expose parallelism but also concern themselves with issues of granularity, load-balancing, synchronization, and communication. This thesis demonstrates that when algorithmic parallelism is expressed in the form of a stream program, a compiler can effectively and automatically manage the parallelism. Our compiler assumes responsibility for low-level architectural details, transforming implicit algorithmic parallelism into a mapping that achieves scalable parallel performance for a given multicore target. Stream programming is characterized by regular processing of sequences of data, and it is a natural expression of algorithms in the areas of audio, video, digital signal processing, networking, and encryption. Streaming computation is represented as a graph of independent computation nodes that communicate explicitly over data channels. Our techniques operate on contiguous regions of the stream graph where the input and output rates of the nodes are statically determinable. Within a static region, the compiler first automatically adjusts the granularity and then exploits data, task, and pipeline parallelism in a holistic fashion. We introduce techniques that data-parallelize nodes that operate on overlapping sliding windows of their input, translating serializing state into minimal and parametrized inter-core communication. Finally, for nodes that cannot be data-parallelized due to state, we are the first to automatically apply software-pipelining techniques at a coarse granularity to exploit pipeline parallelism between stateful nodes. Our framework is evaluated in the context of the StreamIt programming language. StreamIt is a high-level stream programming language that has been shown to improve programmer productivity in implementing streaming algorithms. We employ the StreamIt Core benchmark suite of 12 real-world applications to demonstrate the effectiveness of our techniques for varying multicore architectures. For a 16-core distributed memory multicore, we achieve a 14.9x mean speedup. For benchmarks that include sliding-window computation, our sliding-window data-parallelization techniques are required to enable scalable performance for a 16-core SMP multicore (14x mean speedup) and a 64-core distributed shared memory multicore (52x mean speedup).by Michael I. Gordon.Ph.D

A Grid Based Distributed Cooperative Environment for Health Care Research

International audienceProviding a distributed cooperative environment is a challenging task, which requires a middleware infrastructure that provides, among others, management of distributed shared data, synchronization, consistency, recovery, security and privacy support. In this paper, we present the ECADeG project which proposes a layered architecture for developing distributed cooperative environments running on top of a desktop grid middleware that can encompass multiple organizations. We also present a particular cooperative environment for supporting scientific research focused at the health domain which uses the services supplied by the ECADeG architecture in order to allow researchers to share access to multiple institutions databases, visualize and analyze data by means of data mining techniques, edit research documents cooperatively, exchange information through forums and chats, etc.. Such a rich cooperative environment helps thus the establishment of partnerships between health care professionals and their institutions

GaN heterojunction FET device Fabrication, Characterization and Modeling

This dissertation is focused on the research efforts to develop the growth, processing, and modeling technologies for GaN-based Heterojunction Field Effect Transistors (HFETs). The interest in investigating GaN HFETs is motivated by the advantageous material properties of nitride semiconductor such as large band gap, large breakdown voltage, and high saturation velocity, which make it very promising for the high power and microwave applications. Although enormous progress has been made on GaN transistors in the past decades, the technologies for nitride transistors are still not mature, especially concerning the reliability and stability of the device. In order to improve the device performance, we first optimized the growth and fabrication procedures for the conventional AlGaN barrier HFET, on which high carrier mobility and sheet density were achieved. Second, the AlInN barrier HFET was successfully processed, with which we obtained improved I-V characteristics compared with conventional structure. The lattice-matched AlInN barrier is beneficial in the removal of strain, which leads to better carrier transport characteristics. Furthermore, new device structures have been examined, including recess-gate HFET with n+ GaN cap layer and gate-on-insulator HFET, among which the insertion of gate dielectrics helps to leverage both DC and microwave performances. In order to depict the microwave behavior of the HFET, small signal modeling approaches were used to extract the extrinsic and intrinsic parameters of the device. An 18-element equivalent circuit model for GaN HFET has been proposed, from which various extraction methods have been tested. Combining the advantages from the cold-FET measurements and hot-FET optimizations, a hybrid extraction method has been developed, in which the parasitic capacitances were attained from the cold pinch-off measurements while the rest of the parameters from the optimization routine. Small simulation error can be achieved by this method over various bias conditions, demonstrating its capability for the circuit level design applications for GaN HFET. Device physics modeling, on the other hand, can help us to reveal the underlying physics for the device to operate. With the development of quantum drift-diffusion modeling, the self-consistent solution to the Schrödinger-Poisson equations and carrier transport equations were fulfilled. Lots of useful information such as band diagram, potential profile, and carrier distribution can be retrieved. The calculated results were validated with experiments, especially on the AlInN layer structures after considering the influence from the parasitic Ga-rich layer on top of the spacer. Two dimensional cross-section simulation shows that the peak of electrical field locates at the gate edge towards the drain, and of different kinds of structures the device with gate field-plate was found to efficiently reduce the possibility of breakdown failure

Proportion and the esoteric: Frederick Delius and his music

An analysis of Frederick Delius' earliest compositions showed that he had been intensely involved, especially between 1887 – 1892, in exploring various proportioning strategies in his music. Key to this was his development of three- or four-part configurations or 'patterns'. These were typically constructed so that the two outer sections of a pattern, although separate, were in strict proportion, most frequently in Golden Section (GS) proportion. Patterns that used GS were distinguished from the more familiar 'Type I' GS, as belonging to a 'Type II' GS praxis. Analyses of Delius' later works confirmed that both Types I and II GS proportioning continued to play a critical role in structuring his mature works, often leading in larger compositions to elaborate descending hierarchies of GS (less frequently involving 2: 1 or 1: 1) proportioning. These hierarchies tend to show a top-down, stepwise stratification, large-scale patterns usually being placed at their 'top' – often dominating and spanning entire works or movements. Type I GS and other proportioning strategies are then placed at lower levels. Investigations into possible French sources of Delius’ techniques showed that Debussy had been experimenting initially (from 1887) with a single large-scale GS structuring technique (termed here ‘GS partitioning’) infrequent in Delius. Comparison of 26 components of Delius’ proportioning practice with Debussy’s confirmed however that wherever a technique was shared, it was Delius who had preceded Debussy’s usage, often by a period of several years. Among French artists, Paul Sérusier in 1889 signalled a more complex GS proportioning than hitherto, whilst two of his associates, Charles Filiger and Jan Verkade, also used GS from the early 1890s, the latter showing only a brief interest. Turning to Germany, Emil Naumann, a pupil of Felix Mendelssohn, had been the first to write on GS techniques in music, intimating the use of one technique later taken up by Delius. Several components of Delius proportioning were eventually traced back to Mendelssohn, suggesting both that GS proportioning praxes in 19th century music were being developed in Germany long before the writings of Adolf Zeising or Gustav Fechner, and that Delius had gained his own techniques whilst studying in Leipzig rather than later during his Paris years. Studies in Delius’ social milieu during the 1880s and 1890s suggested that both Delius and his closest friends were pursuing aspects of esoteric knowledge influential on his early works. Thus the operas Irmelin and the Magic Fountain were each laid out as comprehensive alchemical allegories, and confirm that Delius had been strongly attracted to alchemical lore and symbolism sometime before he first met Strindberg. Although no evidence was found of any interest in GS in 19th century esoteric or occult movements, GS and esoterism tended to exist alongside each other, especially in Paris, where they occasionally interacted, as in Delius’ first opera Irmelin where GS was used as a symbol of the alchemist’s gold. An examination of Delius’ vocal texts indicated that they display a strong proclivity towards ascensionism – the impulse to soar upwards. This phenomenon is discussed alongside others in connection with the idea of exceptional or mystical experience having played an intimate role in Delius’ personal life and character

Reports to the President

A compilation of annual reports for the 1988-1989 academic year, including a report from the President of the Massachusetts Institute of Technology, as well as reports from the academic and administrative units of the Institute. The reports outline the year's goals, accomplishments, honors and awards, and future plans

Multi-voxel fMRI analysis using an high throughput grid framework

Mestrado em Engenharia Biomédica - Instrumentação, Sinal e ImagemO presente trabalho apresenta uma nova abordagem à análise de imagens de RMf do cérebro, especificamente a utilização de medidas associativas na análise de séries temporais de RMf. Este tipo específico de análise, computacionalmente intensivo, requer recursos que normalmente não se encontram disponíveis em ambientes clínicos. Redes Grid é um novo paradigma de computação distribuída de elevada performance que pode ser utilizado para potenciar a utilização deste tipo de análise, disponibilizando a capacidade de computação necessária. Implementouse um framework que permite a utilização de uma infraestrutura Grid para correr este tipo de análise de forma transparente, viabilizando a sua utilização em ambientes clínicos, onde o tempo é um factor crítico. ABSTRACT: This work, introduces a new approach to fMRI brain image analysis, namely multivoxel fMRI association analysis. The problem associated with this type of approach is that requires a large computing capacity that is not normally available at clinical sites. To enable this specific type of analysis we are required to use High Performance Computing paradigms. In this context we analysed the use of Grid computing and implemented a framework that allows running the multivoxel fMRI association analysis using a grid infrastructure resources. The use of this framework makes this type of analysis usable in clinical environments where time constraints can have a vital importance

Pharmacophore derivation using discotech and comparison of semi-emperical, AB initio and density functional CoMFA studies for sigma 1 and sigma 2 receptor-ligands

This study describes the development of pharmacophore and CoMFA models for sigma receptor ligands. CoMFA studies were performed for 48 bioactive sigma 1 receptorligands using [H3 ](+) pentazocine as the radioligand, for 30 PCP derivatives for sigma 1 receptor-ligands using [3H](+)SK-F 10047 as the radioligand and for 24 bioactive sigma 2 receptor-ligands using the radioligand [H3](+)DTG in the presence of pentazocine. Distance Comparisons (DISCOtech) was used as the starting point for CoMFA studies. The conformers, derived by DISCOtech were optimized using AMi, or HF/3-21G* in Gaussian 98. The optimized geometries were aligned with the pharmacophore, derived using DISCOtech. Atomic charges were calculated using AMl, HF/3-21G*, B3LYP/3-21G*, MP2/3-21G* methods in Gaussian 98. The CoMFA Maps that were developed using Sybyl 6.9 were compared on steric and electrostatic field differences. With leaveone-out cross validation the numbers of optimal components were decided. Using these numbers of optimal components no cross validation was performed in a training set. After a test set, it was known that CoMFA models derived from HF/3-21G* optimized geometries were more reliable in predicting bioactivities than CoMFA models derived from AMi optimized geometries

Geometric and frequency scalable transistor behavioural model for MMIC design

This thesis presents research in developing and validating scaling in terms of geometry and frequency for Behavioural models in order to extend their functionality. Geometric and frequency scalability, once thought to be limited only to Physical and Compact models, greatly reduces the number of measurements for model generation. Besides saving precious time and effort, measurements do not need to be collected at high frequency or power levels, reducing the cost of purchasing measurement hardware. Scaling in terms of geometry is achieved by combining accurate measurement based non-linear look-up table models of a reference (smaller) transistor with the appropriate passive embedding networks. Experimental results show that the scalable model is successful in predicting the performance of devices up to 5 times larger in gate periphery on two separate Gallium Nitride wafers, one measured at 5 GHz and another at 9 GHz. This approach provides a robust utilization of Behavioural models by providing performance predictions at power levels beyond the limitations of high frequency measurement systems. The geometric scalable Behavioural model was also used in a CAD environment to help create a prototype single cell MMIC amplifier for operation at 5 GHz. Although the targeted performance was not achieved due to mismatch, the non-linear Behavioural model is still able to predict the performance of the actual fabricated circuit. The work in this thesis also introduces the first formulation and approach that enables Behavioural models to be frequency scalable. The experimental results T MINGHAO KOH ABSTRACT IV on HFETs from 2 different Gallium Nitride wafers measured from 2 GHz to 8 GHz (2 octaves), support theoretical analysis that frequency domain Behavioural models defined in the admittance domain have frequency scalable coefficients. Load-pull results show that the model can accurately predict nonlinear behaviour at frequencies that were not used during the model extraction process