Routing and wavelength assignment algorithms for multiclass WDM optical networks

In this paper dynamic routing and wavelength assignment strategies have been proposed for multiclass WDM optical networks. Multiclass optical networks provide multiple classes of services to the subscriber according to the requirement, which in turn increase operational profitability. Each class of service could be characterized by parameters like number of wavelengths, expected call holding time and average arrival rate of request. The proposed strategies have been analyzed and compared with existing strategies on the basis of blocking probabilities for multiclass traffic scenarios. Simulation results on different network topologies demonstrate that the performance of proposed strategies “Fixed shortest/alternate shortest path routing with wavelength reservation (FSASWR)” and “Fixed alternate shortest path routing with least priority wavelength assignment (FASPL)” are much better as compared to existing strategies. Proposed strategies minimize blocking probability of the multiclass network using limited number of wavelengths.     

Arithmetic returns for investment performance measurement

This paper introduces new money-weighted metrics for investment performance analysis, based on arithmetic means of holding period rates weighted by the investment’s market values. This approach generates rates of return which measure a fund’s or portfolio’s performance and a fund manager’s performance. It also enables to show that the Internal Rate of Return (IRR) is a weighted mean of holding period rates associated with interim values which differ from market values, so that value additivity is violated. The manager’s Arithmetic Internal Rate of Return (AIRR) is shown to be the true period equivalent of the cumulative Time Weighted Rate of Return (TWRR), whereas the period TWRR (a geometric return) provides a different ranking. The method is easily generalized for coping with varying benchmark rates. We also cope with the practical problem of estimating interim values whenever they are not available.     

Universal prediction-based adaptive fault estimator applied to secure communication

In this paper, a communication scheme that could use a nonlinear dynamical system to create encrypted keys with an additional dimension is proposed, and the scheme could keep encrypted keys not to diverge. Since the divergence of encrypted keys (nonlinear signals) easily happens in non-linear systems coupled with other systems, the adaptive control approach, proposed in this paper, uses the universal state-space adaptive observer-based fault diagnosis/estimator and the high-performance tracker to eliminate the divergence of encrypted keys. At the same time, the receiver of communication retrieves informal messages by the universal state-space adaptive observer-based fault diagnosis/estimator and the high-performance tracker. Thus, this paper takes advantage of the merit of digital redesign methodology for a practical implementation of secure-communication, and the estimator solves the problem of secure communication. Thus developed a new approach could add more dimensions into nonlinear secure-communication systems without having the problem of divergence of encrypted keys.     

Simulation of quasi-dimensional combustion model for predicting diesel engine performance

In order to improve the precision of quasi-dimensional combustion model for predicting diesel engine performance and promote the real time operating performance of the simulation model, a new phase-divided spray mixing model is proposed and the quasi-dimensional combustion model of diesel engine working process is developed. The software MATLAB/Simulink is utilized to build the quasi-dimensional combustion model of diesel engine working process, and the performance for diesel engine is simulated. The simulation results agree with experimental data quite well. The comparisons between them show that the relative error of power and brake specific fuel consumption is less than 2.8% and the relative error of nitric oxide and soot emissions is less than 9.1%. By utilization of this simulation model with personal computer, the average computational time for one diesel engine working process is 36 s, which presents good real time operating performance of the model. At the same time, the influence of parameters in calculation of air entrainment on prediction precision of diesel engine’s simulation model is analyzed.     

A mathematical model of deterministic wormhole routing in hypercube multicomputers using virtual channels

Although several analytical models have been proposed in the literature for binary n-cubes with deterministic routing, most of them have not included the effects of virtual channel multiplexing on network performance. The only mathematical model for deterministic wormhole routing in hypercubes with virtual channels was proposed in [Y. Boura, Design and Analysis of Routing Schemes and Routers for Wormhole-routed Mesh Architectures, Ph.D. Thesis, Department of Computer Science and Engineering, Pennsylvania State University, 1995] which uses complex combinatorial analysis with a computation time of O(N=2ⁿ) for an n-dimensional hypercube. This paper proposes a new and simple analytical model to compute message latency in binary n-cubes with virtual channels. It is very simple and easy to understand which uses an average case analysis and requires a computation time of O(n) for an n-dimensional hypercube. Results from simulation experiments confirm that the proposed model exhibits a good degree of accuracy for various network sizes and under different operating conditions.     

变压器强迫油导向循环风冷系统性能试验

介绍了变压器强迫油导向循环风冷却器控制原理。针对日常运行中可能出现的各种故障,详细列出了冷却系统性能试验步骤。     

体育行政绩效的成本与效益分析

结合当前我国体育行政部门的现状，依据经济学、政治学和社会学理论，本文从体育行政绩效的基本涵义出发，探讨有关体育行政绩效的成本与效益问题，旨在引起更多人对体育行政部门绩效理论的探讨和研究，从而为进一步改善和优化我国体育行政管理提供科学的理论指导。     

工件有到达时间的两机器自由作业稠密时间表

对于两机器自由作业加工总长问题，工件带有到达时间，我们证明了稠密时间表的性能比为1.5。     

A modified HOL priority scheduling discipline: Performance analysis

In this paper, we introduce and analyze a modified HOL (head-of-the-line) priority scheduling discipline. The modification is incorporated to cope with the so-called starvation problem of regular HOL priority queues. We consider a discrete-time single-server queueing system with two priority queues of infinite capacity and with the introduced priority scheme. We show that the use of probability generating functions is suitable for analyzing the system contents and the packet delay. Some performance measures (such as means and variances) of these stochastic quantities will be derived. Furthermore, approximate expressions of the tail probabilities are obtained from the probability generating functions, by means of the dominant-singularity method. These expressions, together with their characteristics, constitute one of the main contributions of this paper. Finally, the impact and significance of the m-HOL (modified HOL) priority scheduling on these performance measures is illustrated by some numerical examples.     

Benchmarking with quality-adjusted DEA (Q-DEA) to seek lower-cost high-quality service: Evidence from a U.S.bank application

Benchmarking is a widely cited method to identify and adopt best-practices as a means to improve performance. Data envelopment analysis (DEA) has been demonstrated to be a powerful benchmarking methodology for situations where multiple inputs and outputs need to be assessed to identify best-practices and improve productivity in organizations. Most DEA benchmarking studies have excluded quality, even in service-sector applications such as health care where quality is a key element of performance. This limits the practical value of DEA in organizations where maintaining and improving service quality is critical to achieving performance objectives. In this paper, alternative methods incorporating quality in DEA benchmarking are demonstrated and evaluated. It is shown that simply treating the quality measures as DEA outputs does not help in discriminating the performance. Thus, the current study presents a new, more sensitive, quality-adjusted DEA (Q-DEA), which effectively deals with quality measures in benchmarking. We report the results of applying Q-DEA to a U.S. bank's 200-branch network that required a method for benchmarking to help manage operating costs and service quality. Q-DEA findings helped the bank achieve cost savings and improved operations while preserving service quality, a dimension critical to its mission. New insights about ways to improve branch operations based on the best-practice (high-quality low-cost) benchmarks identified with Q-DEA are also described in the paper. This demonstrates the practical need and potential benefits of Q-DEA and its efficacy in one application, and also suggests the need for further research on measuring and incorporating quality into DEA benchmarking. The review process of this paper was handled by the Edit-in-Chief Peter Hammer.