scholarly journals Impact of Modern Virtualization Methods on Timing Precision and Performance of High-Speed Applications

2019 ◽  
Vol 11 (8) ◽  
pp. 179 ◽  
Author(s):  
Veronika Kirova ◽  
Kirill Karpov ◽  
Eduard Siemens ◽  
Irina Zander ◽  
Oksana Vasylenko ◽  
...  

The presented work is a result of extended research and analysis on timing methods precision, their efficiency in different virtual environments and the impact of timing precision on the performance of high-speed networks applications. We investigated how timer hardware is shared among heavily CPU- and I/O-bound tasks on a virtualized OS as well as on bare OS. By replacing the invoked timing methods within a well-known application for estimation of available path bandwidth, we provide the analysis of their impact on estimation accuracy. We show that timer overhead and precision are crucial for high-performance network applications, and low-precision timing methods usage, e.g., the delays and overheads issued by virtualization result in the degradation of the virtual environment. Furthermore, in this paper, we provide confirmation that, by using the methods we intentionally developed for both precise timing operations and AvB estimation, it is possible to overcome the inefficiency of standard time-related operations and overhead that comes with the virtualization. The impacts of negative virtualization factors were investigated in five different environments to define the most optimal virtual environment for high-speed network applications.

2018 ◽  
Vol 11 (6) ◽  
pp. 199 ◽  
Author(s):  
Amirreza Salehipour ◽  
Abdollah Ah mand

Necessity of improving employees’ performance in ministry of education in Iran was the reason of conducting this research. Authors are focused on the impact of High Performance Work System (HPWS) and the culture of organization on employees’ performance in Iran ministry of education. By conducting specified study based on distributed survey questionnaire to 162 members of ministry of education in Iran, this study aims to provide answer to the given research questions of study. The outcome of hypotheses testing illustrate HPWS significantly effects ministry members’ performance and shows strong relation between variables. Likewise, organizational culture demonstrates significant affirmative impact on Iran ministry of education members and employees’ performance. Findings of current research indicate that the ministry of education in Iran requires immediate action toward improving performance of members to obtain desired outcome. Accordingly, to the result of present study, current research attempts to provide practical concepts and illustrate limitations, suggestions for improvement of ministry and future study in this field.


Author(s):  
David J. Wren ◽  
Patrick Reid ◽  
Len L. Wright

The ACR-1000™ design is an evolutionary advancement of the proven CANDU® reactor design that delivers enhanced economic performance, safety, operability and maintainability. The fuel for the ACR-1000 design is based on the well established CANDU fuel bundle design that has over 40 years of demonstrated high performance. Building on its extensive experience in fuel design and analysis, and fuel testing, AECL has designed a CANFLEX-ACR™ fuel bundle that incorporates the latest improvements in CANDU fuel bundle design. The ACR-1000 fuel bundle also includes features that enable the ACR-1000 to achieve higher fuel burn-up and improved reactor core physics characteristics. To verify that the CANFLEX-ACR fuel bundle design will meet and exceed all design requirements, an extensive program of design analysis and testing is being carried out. This program rigorously evaluates the ability of the fuel design to meet all design and performance criteria and particularly those related to fuel failure limits. The design analyses address all of the phenomena that affect the fuel during its residence in the reactor core. Analysis is performed using a suite of computer codes that are used to evaluate the temperatures, deformations, stresses and strains experienced by the fuel bundle during its residence in the reactor core. These analyses take into account the impact of fuel power history and core residence time. Complementing the analyses, testing is performed to demonstrate the compatibility of the fuel with the reactor heat transport system and fuel handling systems, and to demonstrate the ability of the fuel to withstand the mechanical forces that it will experience during its residence in the core. The testing program includes direct measurement of prototype fuel element and fuel bundle properties and performance limits. A number of different test facilities are used including a cold test loop and a hot test loop with a full-scale ACR-1000 fuel channel that operates at reactor coolant temperatures, pressures and flows. This paper summarizes the out-reactor test program and related analysis that provide the basis for verifying that the ACR-1000 fuel design meets its requirements.


Author(s):  
Mr.M.V. Sathish ◽  
Mrs. Sailaja

A new architecture of multiplier-andaccumulator (MAC) for high-speed arithmetic. By combining multiplication with accumulation and devising a hybrid type of carry save adder (CSA), the performance was improved. Since the accumulator that has the largest delay in MAC was merged into CSA, the overall performance was elevated. The proposing method CSA tree uses 1’s-complement-based radix-2 modified Booth’s algorithm (MBA) and has the modified array for the sign extension in order to increase the bit density of the operands. The proposed MAC showed the superior properties to the standard design in many ways and performance twice as much as the previous research in the similar clock frequency. We expect that the proposed MAC can be adapted to various fields requiring high performance such as the signal processing areas.


2014 ◽  
Vol 23 (1) ◽  
pp. 33-50 ◽  
Author(s):  
Gabor Aranyi ◽  
Sid Kouider ◽  
Alan Lindsay ◽  
Hielke Prins ◽  
Imtiaj Ahmed ◽  
...  

The performance of current graphics engines makes it possible to incorporate subliminal cues within virtual environments (VEs), providing an additional way of communication, fully integrated with the exploration of a virtual scene. In order to advance the application of subliminal information in this area, it is necessary to explore in the psychological literature how techniques previously reported as rendering information subliminal can be successfully implemented in VEs. Previous literature has also described the effects of subliminal cues as quantitatively modest, which raises the issue of their inclusion in practical tasks. We used a 3D rendering engine (Unity3D) to implement a masking paradigm within the context of a realistic scene and a familiar (kitchen) environment. We report significant effects of subliminal cueing on the selection of objects in a virtual scene, demonstrating the feasibility of subliminal cueing in VEs. Furthermore, we show that multiple iterations of masked objects within a trial, as well as the speeding of selection choices, can substantially reinforce the impact of subliminal cues. This is consistent with previous findings suggesting that the effect of subliminal stimuli fades rapidly. We conclude by proposing, as part of further work, possible mechanisms for the inclusion of subliminal cueing in intelligent interfaces to maximize their effects.


Author(s):  
Manudul Pahansen de Alwis ◽  
Karl Garme

The stochastic environmental conditions together with craft design and operational characteristics make it difficult to predict the vibration environments aboard high-performance marine craft, particularly the risk of impact acceleration events and the shock component of the exposure often being associated with structural failure and human injuries. The different timescales and the magnitudes involved complicate the real-time analysis of vibration and shock conditions aboard these craft. The article introduces a new measure, severity index, indicating the risk of severe impact acceleration, and proposes a method for real-time feedback on the severity of impact exposure together with accumulated vibration exposure. The method analyzes the immediate 60 s of vibration exposure history and computes the severity of impact exposure as for the present state based on severity index. The severity index probes the characteristic of the present acceleration stochastic process, that is, the risk of an upcoming heavy impact, and serves as an alert to the crew. The accumulated vibration exposure, important for mapping and logging the crew exposure, is determined by the ISO 2631:1997 vibration dose value. The severity due to the impact and accumulated vibration exposure is communicated to the crew every second as a color-coded indicator: green, yellow and red, representing low, medium and high, based on defined impact and dose limits. The severity index and feedback method are developed and validated by a data set of 27 three-hour simulations of a planning craft in irregular waves and verified for its feasibility in real-world applications by full-scale acceleration data recorded aboard high-speed planing craft in operation.


1996 ◽  
Vol 5 (1) ◽  
pp. 136-145 ◽  
Author(s):  
Mark R. Mine ◽  
Hans Weber

Oth law of model dynamics: In a finite (and usually very short) amount of time, users of a graphics system will generate a model that shall bring said system to its knees. The purpose of this paper is to discuss our experiences with the impact of megamodels on interactive virtual environments. We consider a megamodel to be any model that causes the Oth law of model dynamics to come into effect. We will demonstrate how working with megamodels quickly reveals the limitations of the graphics hardware and software being used to support the virtual environment. We will give examples, based upon our experiences on the Architectural Walkthrough Project here at the University of North Carolina at Chapel Hill (UNC), of the kinds of extra effort required to overcome these limitations.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Jie Hong ◽  
Tianrang Li ◽  
Zhichao Liang ◽  
Dayi Zhang ◽  
Yanhong Ma

Aeroengines pursue high performance, and compressing blade-casing clearance has become one of the main ways to improve turbomachinery efficiency. Rub-impact faults occur frequently with clearance decreasing. A high-speed rotor-support-casing test rig was set up, and the mechanism tests of light and heavy rub-impact were carried out. A finite element model of the test rig was established, and the calculation results were in good agreement with the experimental results under both kinds of rub-impact conditions. Based on the actual blade-casing structure model, the effects of the major physical parameters including imbalance and material characteristics were investigated. During the rub-impact, the highest stress occurs at the blade tip first and then it is transmitted to the blade root. Deformation on the impact blade tip generates easily with decreased yield strength, and stress concentration at the blade tip occurs obviously with weaker stiffness. The agreement of the computation results with the experimental data indicates the method could be used to estimate rub-impact characteristics and is effective in design and analyses process.


2019 ◽  
Vol 45 (1) ◽  
pp. 18-29
Author(s):  
Burak Cem Konduk

This study investigates whether and how the impact of drivers of aspiration levels changes across the cases of consistent and inconsistent performance feedback within the context of a retailer. Analysis of internal corporate data shows that while past aspiration level and performance–aspiration gap positively influence the current aspiration level in the case of inconsistent feedback, performance feedback consistency changes only the impact of performance relative to peers. This study replicates past research in a different industry and country due to limited empirical evidence, introduces real-world complexity into aspiration theory, pinpoints performance–aspiration gap as the primary performance feedback, introduces a new sign for the impact of performance relative to peers, and reconciles its previously detected mixed impact. The findings suggest that organizational attention has an inward focus in the case of inconsistent feedback. The results also point out that leaders can trigger change through a performance outcome that lags behind the corresponding aspiration level rather than the performance of peers and eventually move their organizations toward high performance targets by starting with feasible rather than stretch goals.


2013 ◽  
Vol 760-762 ◽  
pp. 2010-2013
Author(s):  
Hui Qing Qiu ◽  
Cong Wang ◽  
Jie Lu

A technique of high-speed network intrusion detection system based on packet sampling theory is proposed. Starting with basic principles of packet sampling, this paper first analyses the significant mathematical conclusion of sampling strategies, then after discussing current strategies, mechanism and performance of different packet sampling methods, we specify an efficient strategy of packet sampling. Results show that this method can attain above 55% accurate rate with below 1% false rate in 94 specified attacking cases from DARPA 2000 IDS evaluation dataset.


2010 ◽  
Vol 19 (03) ◽  
pp. 655-669 ◽  
Author(s):  
FANG WANG

Advance in semiconductor technologies enables seamless integration of hundreds of cores on a single silicon die, which requires high communication performance. To deal with the increasing communication complexity of System-on-Chip (SoC), Network-on-Chip (NoC) has been recently proposed as an alternative to the conventional point-to-point links and bus based communication fabrics. In practice, to facilitate NoC design evaluation and optimization, Poisson traffic or Bernoulli traffic models are generally assumed. However, actual measurements showed that real high speed network traffic always has strong correlations. The objective of this paper is to investigate the impact of traffic correlations on the performance of NoC design. Experimental results show that traffic correlation degrades the performance of NoC design and unrealistic traffic assumptions may yield unacceptable designs.


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