Papers by Keyword: Reliability Optimization

Abstract: Unmanned aerial vehicles (UAVs) are used predominately for military applications, despite a growing number of emerging civilian tasks. One of the key tasks for increasing the advantages over a manned aircraft are to extend the flight duration of the UAV. Long endurance flights demand an engine that adapts to variable weather and atmospheric conditions as well as to changes in altitude. Varying demand of the UAV for power is compared to determine the needs for our mid-class test platform. The paper presents a solution to a high-efficiency engine and suggests a test layout for assessing reliability and optimal performance.

Abstract: With the rapid development of economy, computer technology with the advantages of real-time performance, and high efficiency has been rapidly applied in the field of financial management. The construction of financial management system, which is of digitization and informationization, becomes more and more comprehensive. How to determine the "optimal cash holdings" is the key and difficult decision for financial management in modern enterprises. This paper firstly discusses the development status of modern computer financial management technology, and then makes comparative analysis of the existing four kinds of optimal cash holdings models. On this basis, it has constructed the optimal cash holdings model with Baumol by the aid of computer technology, and the model has been carried out computer simulation and analysis in this paper. The results show that the constructed optimal cash holdings model can help enterprise finance make reasonable decision, which is very helpful to improve the efficiency of financial management.

Abstract: In this paper, an algorithm based ant colony approach (ACA) is designed to find the optimal configuration for redundancy apportionment problem (RAP) of series-parallel multi-state system (MSS). In order to achieve maximum system reliability under cost and performance constraints, the algorithm takes advantage of ACA’s combinatorial optimization, uses heuristic information about reliability to arrange components from available choice. Different from traditional nominal performance and reliability system, universal generating function (UGF) is introduced and used to estimate the multi-state system reliability. Finally the experiment has shown that the presented algorithm can provide optimal and near optimal solutions, and have efficient and convenient calculation performance.

Abstract: Aiming at the randomness and variability of geotechnical parameters, the uniform test and nonparametric regression technique of alternating conditional expectation (ACE) is used to establish the efficiency response surface. On the basis of response surface, the Monte Carlo method was used to research the reliability optimal design and analysis method of soil nailing structure. Considering various failure modes of soil nailing structure, and setting the system failure probability as constraint, and per linear meter length of soil nail as the objective function, than to establish the reliability optimal model of soil nailing structure of foundation pit with the indexes of soil shear strength c, φ and ground overload as random variables. Through an engineering case analysis, the feasibility and effectiveness of this method are verified. Finally, the superiority of the proposed method is proved compared with the deterministic method.

Abstract: This paper can be asserted that the use of parallel genetic algorithm can not only effectively improve the calculation speed and optimize the quality, but also can improve a lot of advantages. Reliability optimization for computer net works, subject s to cost constraints, is a NP-hard combinational problem. Reg ar ding a known network topology, the problem of choosing links and switchers among alternatives different in reliability and cost is settled by a Coarse-grained parallel genetic algorithm, which maximize the network availablity within a fixed budget. T he simulations on a dedicated cluster demonst rate that contracting to the sequential counterpart, o ur par allel GA improves the quality of plans greatly with an evident speed-up.

Abstract: Reliability allocation optimization problem of a complex mechatronic system is a highly nonlinear constrained optimization problem, and hence solution to this kind of problem is of NP-hardness even with moderate scale. Due to the nonlinearity combined with multiple local extreme values, traditional optimization techniques fail to arrive at the global or nearly global optimal solution to the problem. Genetic algorithm incorporated with neighboring domain traversal searching technique is utilized in this paper to solve the complex mechatronic system reliability optimization allocation problem. Reliability allocation optimization of the life-support system in a space capsule, being a typical non serial-parallel system, is specifically demonstrated to show the satisfactory convergence performance as well as the important practical value of hybrid genetic algorithm. The simulation results show that the proposed method may gain better precision in solving the complex mechatronic system reliability optimization problem.

Abstract: Based on the reliability-based optimization design theory, the reliability sensitivity technique and the robust design method, the reliability-based robust design of rubbing rotor system is extensively discussed and a numerical method for reliability-based robust design is proposed. The reliability sensitivity is added to the reliability-based optimization design model and the reliability-based robust design is described as a multi-objection optimization. On the condition of known first four moments of basic random variables, the respective program can be used to obtain the reliability-based robust design information of rubbing rotor system accurately and quickly using the fourth moment technique. According to the numerical results, the approach proposed is a convenient and practical reliability-based roust design method.

Abstract: In the optimization design for steering mechanism of trucks, considering the impact of controllable factors and noise factors, based on the reliability optimization theory, the stable reliability sensitivity method and the robust design method, the robust reliability design for steering mechanism of trucks is extensively discussed. Compared with the conventional probabilistic reliability optimization approach, the proposed method does not require a presumed probability distribution of the uncertain parameters and only the bounds or ranges of their variations are required. The movement precision is chosen as objective function and kingpins distance, axle base, the bottom angle of trapezoid and the arm length are chosen as design variables.