Optimum allocation of computer spares for three-level stocks

This paper presents a model for determining the optimum stock in a three level depots system. The method for determining stock levels uses “incremental performance per price algorithm” (IPPA) and the “new Lawler-Bell algorithm” (NLB). The practical calculation is carried out on a computer, the results being presented in the form of a list of necessary spare units from the first to the third level.     

Optimal allocation for a repairable system

A system is composed of n series subsystems. Each subsystem consists of some same type of parallel or cold stand-by components. These components are repairable. We discuss the optimal allocation of this system under various constraints, and give some procedures for solution of this problem.     

Optimal allocation of multistate elements in a linear consecutively-connected system

A linear consecutively-connected system consists of N+1 linear ordered positions. M s-independent multistate elements with different characteristics are to be allocated to the first N positions. Each element can provide a connection between the position to which it is allocated and the next few positions. The reliability of the connection for any given element depends on: (1) the position to which it is allocated; and (2) the number of positions it connects. The system fails if the first position (source) is not connected with the N+1 position (sink). An algorithm based on the universal generating function method is suggested for the linear consecutively-connected system reliability determination. This algorithm can handle cases in which any number of multistate elements are allocated in the same position while some positions remain empty. In many cases, such uneven allocation provides greater system reliability than the even one. A genetic algorithm is used as an optimization tool to solve the optimal element-allocation problem.     

Optimal allocation of cost to detectors in a two-unit series system

A two-unit series system, in which each unit is equipped with a separate detector to detect failure, is considered. The probability that a detector operates successfully at the time of need (i.e. when system fails) is a function of cost spent on the detector. The problem is that of allocation of total resources (cost) to the two detectors such that the overall expected profit is maximized. The optimization problem has been formulated. Two examples are included to show the uses of results.     

A priority multi-component system with spares

A system with n similar components in series with constant failure rates and m spares in warm standby supported by a single repair facility is studied. The repair time distributions of on-line and standby failures are taken to be different and arbitrary. Two models, one with pre-emptive repeat priority and another with non-pre-emptive priority are discussed. Equations for the reliability and availability functions are obtained for both cases and earlier results are recovered as special cases of the non-pre-emptive model.     

多功能计算机控制、切换和报警系统的设计

介绍了集多媒体技术、视频、音频、控制和报警技术于一体的多功能计算机控制、切换和报警系统的组成、工作原理、基本功能、关键技术和设计方法。     

Availability of a series system with warm spares

We discuss two models for the availability of a series system of components with warm spares, serviced by a single service facility. Replacement of failed components by a spare has pre-emptive priority over repair of the failed components; for the restart model, in which interrupted repairs restart from the beginning, we find the availability of the system; for the resume model, in which interrupted repairs resume from where they left off, we show how to obtain the availability of the system. Some numerical examples and the distributions of system downtime are given for both models.     

含大规模风电的电力系统储能电源优化配置研究

随着化石能源枯竭和大气污染等问题的日益深化,风力发电在现阶段的发展中得到了快速的发展.藉此,本文立足于现阶段我国风力发电发展现状,对风电的电力系统储能电源的优化配置进行了深入的研究.     

Optimal testing resource allocation, and sensitivity analysis in software development

We consider two kinds of software testing-resource allocation problems. The first problem is to minimize the number of remaining faults given a fixed amount of testing-effort, and a reliability objective. The second problem is to minimize the amount of testing-effort given the number of remaining faults, and a reliability objective. We have proposed several strategies for module testing to help software project managers solve these problems, and make the best decisions. We provide several systematic solutions based on a nonhomogeneous Poisson process model, allowing systematic allocation of a specified amount of testing-resource expenditures for each software module under some constraints. We describe several numerical examples on the optimal testing-resource allocation problems to show applications & impacts of the proposed strategies during module testing. Experimental results indicate the advantages of the approaches we proposed in guiding software engineers & project managers toward best testing resource allocation in practice. Finally, an extensive sensitivity analysis is presented to investigate the effects of various principal parameters on the optimization problem of testing-resource allocation. The results can help us know which parameters have the most significant influence, and the changes of optimal testing-effort expenditures affected by the variations of fault detection rate & expected initial faults.     

铁电存储器FM3116在复费率电能表中的应用

FM3116是Ramtron公司基于12C的具有多种功能的铁电存储器,具有存储速度快,功耗低,非易失存储等特点,提出了一种FM3116在复费率电能表中的应用设计,并给出基于FM3116的电能表存储系统的软硬件设计。     

Optimal resource allocation in multiservice CDMA networks

This paper addresses the problem of dynamic resource allocation in a multiservice direct-sequence code-division multiple-access (DS-CDMA) wireless network supporting real-time (RT) and nonreal-time (NRT) communication services. For RT users, a simple transmission power allocation strategy is assumed that maximizes the amount of capacity available to NRT users without violating quality of service requirements of RT users. For NRT users, a joint transmission power and spreading gain (transmission rate) allocation strategy, obtained via the solution of a constrained optimization problem, is provided. The solution maximizes the aggregate NRT throughput, subject to peak transmission power constraints and the capacity constraint imposed by RT users. The optimization problem is solved in a closed form, and the resulting resource allocation strategy is simple to implement as a hybrid CDMA/time-division multiple-access strategy. Numerical results are presented showing that the optimal resource allocation strategy can offer substantial performance gains over other conventional resource allocation strategies for DS-CDMA networks.     

Optimal resource allocation in uplink SC-FDMA systems

We present algorithms for resource allocation in Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, which is the uplink multiple access scheme considered in the Third Generation Partnership Project-Long Term Evolution (3GPP-LTE) standard. Unlike the well-studied problem of Orthogonal Frequency Division Multiple Access (OFDMA) resource allocation, the "subchannel adjacency" restriction, whereby users can only be assigned multiple subchannels that are adjacent to each other, makes the problem much harder to solve. We present a novel reformulation of this problem as a pure binary-integer program called the set partitioning problem, which is a well studied problem in operations research. We also present a greedy heuristic algorithm that approaches the optimal performance in cases of practical interest. We present simulation results for 3GPP-LTE uplink scenarios.     

Optimal power and subcarrier allocation with partial side information for downlink OFDMA system

In this paper,we investigate the power and subcarrier allocation issue in the case of partial side information for downlink orthogonal frequency division multiple access(OFDMA)system.Relaxation method is utilized to characterize the necessary conditions of the optimal solution and the uniqueness of the optimal solution is proved.The game theoretical concept,surplus function is also introduced to analyze the optimal solution.Based on the theoretical analysis,we propose iterative surplus balancing algorithm(ISBA)that can jointly assign the power and subcarriers in multiple rounds,and then the optimality of ISBA is proved.Simulation results are presented to show the characteristics of the theoretical analysis and ISBA.     

Optimal bit allocation for noisy channels

An asymptotic expression for the optimal bit allocation for noisy channels is derived using high-resolution quantisation theory. Theoretically determined bit allocation based on the derived expression is presented.     

Optimal bit allocation for FGS coding

A new bit allocation scheme for fine-granular-scalability (FGS) video coding is proposed. Differing from traditional bit allocation schemes, the focus is on understanding the relationship between rate-distortion analysis and nonzero binary-scaled coefficients (NZBC) in the bitplane coding. An optimal strategy for NZBC coding is then derived and experimental results are given for a comparison of the new scheme with uniform bit allocation.     

Effect of DOA spares on predicted system reliability [switchingsystem]

The authors examine the effect of the initially defective probability, or as it is also known, the dead-on-arrival (DOA) probability, of spare circuit packs on the predicted reliability of a duplex system. A reliability model to incorporate the DOA probability and the associated spare-pack replacement time is developed. Calculations are made in an attempt to quantify the effect of these two variables on the predicted downtime of a representative duplex system. For the system used in this study, it is shown that if the DOA probability is 5% or more, the predicted downtime estimate is 70% greater than the estimate obtained using the standard assumption of a DOA probability of zero     

基于DSP的多功能电子测量系统设计

世界经济的发展带动着信息技术的不断更新,我国的电子测量技术要实现从低科技含量向高科技智能化水平发展;文中通过DSP的多功能电子测量技术的原理和现状问题进行分析;为DSP多功能电子测量系统提出合理的设计建议。     

Optimal allocation of bandwidth for source coding, channel coding, and spreading in CDMA systems

This paper investigates the tradeoffs between source coding, channel coding, and spreading in code-division multiple-access systems, operating under a fixed total bandwidth constraint. We consider two systems, each consisting of a uniform source with a uniform quantizer, a channel coder, an interleaver, and a direct-sequence spreading module. System A is quadrature phase-shift keyed modulated and has a linear block channel coder. A minimum mean-squared error receiver is also employed in this system. System B is binary phase-shift keyed modulated. Rate-compatible punctured convolutional codes and soft-decision Viterbi decoding are used for channel coding in system B. The two systems are analyzed for both an additive white Gaussian noise channel and a flat Rayleigh fading channel. The performances of the systems are evaluated using the end-to-end mean squared error. A tight upper bound for frame-error rate is derived for nonterminated convolutional codes for ease of analysis of system B. We show that, for a given bandwidth, an optimal allocation of that bandwidth can be found using the proposed method.     

Optimal allocation and control problems for software-testingresources

Two kinds of software-testing management problems are considered: testing-resource allocation to best use specified testing resources during module testing, and a testing-resource control problem concerning how to spend the allocated amount of testing-resource expenditures during it. A software reliability growth model based on a nonhomogeneous Poisson process is introduced. The model describes the time-dependent behavior of software errors detected and testing-resource expenditures spent during the testing. The optimal allocation and control of testing resources among software modules can improve reliability and shorten the testing stage. Based on the model, numerical examples of these two software testing management problems are presented