13,152 research outputs found
Agent-based resource management for grid computing
No full textA computational grid is a hardware and software infrastructure that provides
dependable, consistent, pervasive, and inexpensive access to high-end
computational capability. An ideal grid environment should provide access to the
available resources in a seamless manner. Resource management is an important
infrastructural component of a grid computing environment. The overall aim of
resource management is to efficiently schedule applications that need to utilise the
available resources in the grid environment. Such goals within the high
performance community will rely on accurate performance prediction capabilities.
An existing toolkit, known as PACE (Performance Analysis and Characterisation
Environment), is used to provide quantitative data concerning the performance of
sophisticated applications running on high performance resources. In this thesis an
ASCI (Accelerated Strategic Computing Initiative) kernel application, Sweep3D,
is used to illustrate the PACE performance prediction capabilities. The validation
results show that a reasonable accuracy can be obtained, cross-platform
comparisons can be easily undertaken, and the process benefits from a rapid
evaluation time. While extremely well-suited for managing a locally distributed
multi-computer, the PACE functions do not map well onto a wide-area
environment, where heterogeneity, multiple administrative domains, and communication irregularities dramatically complicate the job of resource
management. Scalability and adaptability are two key challenges that must be
addressed.
In this thesis, an A4 (Agile Architecture and Autonomous Agents) methodology is
introduced for the development of large-scale distributed software systems with
highly dynamic behaviours. An agent is considered to be both a service provider
and a service requestor. Agents are organised into a hierarchy with service
advertisement and discovery capabilities. There are four main performance
metrics for an A4 system: service discovery speed, agent system efficiency,
workload balancing, and discovery success rate.
Coupling the A4 methodology with PACE functions, results in an Agent-based
Resource Management System (ARMS), which is implemented for grid
computing. The PACE functions supply accurate performance information (e. g.
execution time) as input to a local resource scheduler on the fly. At a meta-level,
agents advertise their service information and cooperate with each other to
discover available resources for grid-enabled applications. A Performance
Monitor and Advisor (PMA) is also developed in ARMS to optimise the
performance of the agent behaviours.
The PMA is capable of performance modelling and simulation about the agents in
ARMS and can be used to improve overall system performance. The PMA can
monitor agent behaviours in ARMS and reconfigure them with optimised
strategies, which include the use of ACTs (Agent Capability Tables), limited
service lifetime, limited scope for service advertisement and discovery, agent
mobility and service distribution, etc.
The main contribution of this work is that it provides a methodology and
prototype implementation of a grid Resource Management System (RMS). The
system includes a number of original features that cannot be found in existing
research solutions
Surface Potential Decay and DC Conductivity of TiO<sub>2</sub>-based Polyimide Nanocomposite Films
No full textPolymer nanocomposites have attracted wide interest as a method of enhancing polymer properties and extending their applications. Surface potential decay has been used widely as a tool to monitor charge transport and trapping characteristics of insulating materials. Polyimide (PI) as an engineering material has been paid more attention due to high thermal and chemical stability, good mechanical property and excellent insulating property in a wide range of temperature. There has been a lot of work over last few years on optical, thermal and mechanical properties of polyimide nanocomposites. However, little attention has been given to the effect of nano-fillers on charge transport and trapping in polyimide nanocomposites. In the present paper, pure, 1%, 3%, 5% and 7% polyimide nanocomposites was examined by using surface potential decay in conjunction with dc conductivity measurement and both experiments showed that 3% is the optimal value for electrical insulation
sj-docx-2-npx-10.1177_1934578X241238904 - Supplemental material for Tripterygium Glycosides in the Treatment of Asthma: Integrating Network Pharmacology, Molecular Docking and <i>In Vitro</i> Preliminary Pharmacological Evaluation
No full textSupplemental material, sj-docx-2-npx-10.1177_1934578X241238904 for Tripterygium Glycosides in the Treatment of Asthma: Integrating Network Pharmacology, Molecular Docking and In Vitro Preliminary Pharmacological Evaluation by Shuhui Gao, Min Yan, Tianci Jiang, Jingyao Lian, Zhe Cheng, Huahui Zeng and Junwei Zhao in Natural Product Communications</p
sj-docx-1-npx-10.1177_1934578X241238904 - Supplemental material for Tripterygium Glycosides in the Treatment of Asthma: Integrating Network Pharmacology, Molecular Docking and <i>In Vitro</i> Preliminary Pharmacological Evaluation
No full textSupplemental material, sj-docx-1-npx-10.1177_1934578X241238904 for Tripterygium Glycosides in the Treatment of Asthma: Integrating Network Pharmacology, Molecular Docking and In Vitro Preliminary Pharmacological Evaluation by Shuhui Gao, Min Yan, Tianci Jiang, Jingyao Lian, Zhe Cheng, Huahui Zeng and Junwei Zhao in Natural Product Communications</p
Author Correction: Human fingerprint in global weather
No full textIn the version of this News & Views originally published, the ref. 5 author surnames Meihnausen, Fisher and Szekely were spelled incorrectly; they should have been spelled Meinshausen, Fischer and Székely, respectively. This has now been corrected. © 2020, Springer Nature Limited.11Nsciessciscopu
sj-docx-3-npx-10.1177_1934578X241238904 - Supplemental material for Tripterygium Glycosides in the Treatment of Asthma: Integrating Network Pharmacology, Molecular Docking and <i>In Vitro</i> Preliminary Pharmacological Evaluation
No full textSupplemental material, sj-docx-3-npx-10.1177_1934578X241238904 for Tripterygium Glycosides in the Treatment of Asthma: Integrating Network Pharmacology, Molecular Docking and In Vitro Preliminary Pharmacological Evaluation by Shuhui Gao, Min Yan, Tianci Jiang, Jingyao Lian, Zhe Cheng, Huahui Zeng and Junwei Zhao in Natural Product Communications</p
Digital holographic shape measurement using Fizeau microscopy
No full textWe present a Fizeau interferometer using a microscopic objective as a tool for surface contouring without the need for a numerical lens for reconstruction. The interferometer is associated with a telescope system to feature the object with collimated light. The experiment is conducted on two objects possessing different step heights. The phase maps from the captured off-axis holograms are calculated numerically, which allows us to deduce the contours of the objects. The great advantages of the presented technique are that it can be done in real time and there is no need for numerical lenses for micro-objects reconstruction
Real-time visualization of fluidic field using point-diffraction digital holographic interferometry
No full textSingle-beam phase retrieval with partially coherent light illumination
No full textA single-beam phase retrieval method with partially coherent illumination is proposed. By using an obverse and reverse iterative (ORI) algorithm, objects can be reconstructed within less time by recording a sequence of diffraction patterns at different axial planes under partially coherent light illumination. Partially coherent light illumination reduces coherent noise and the number of diffraction patterns needed for reconstruction. Thus, the whole process is fast and has high immunity to external perturbation due to the reference-less configuration. Both simulation and experimental results are presented to demonstrate the feasibility of the proposed approach
A synthetic aperture telescope based on a pair of gratings
No full textA synthetic aperture is an effective approach to enhancement of the resolution of telescopes. In this paper, a new method to improve the resolution by using a pair of gratings is proposed. It allows collection of parts of the light diffracted from the object which could not previously reach the imaging device. This method improves the resolution and light energy utilization ratio of telescopes without introducing new chromatic aberration. An experiment for resolution testing was carried out and the feasibility and availability of the method were verified
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