Optimal Load Allocation Research Articles

Non-Uniform Flow Effect on Optimal Waste Load Allocation in Rivers

In this study, the effects of non-uniform flow due to: (i) inflow from tributaries and (ii) the presence of a downstream control structure (such as a weir or a barrage), on the optimal waste load allocation decision and the resulting cost-equity trade-off relationships, have been investigated. These effects are illustrated with in the framework of a typical cost-equity multi-objective optimization model for optimal waste load allocation in rivers. This framework consists of an embedded river water quality simulator with gradually varied flow and transport (BOD-DO) modules and a cost-equity multi-objective optimization model. A multi-objective evolutionary algorithm known as Non-dominated Sorting Genetic Algorithm-II is used for solving the optimization problem. The optimal fraction removal levels, the treatment cost and the system inequity measure are under predicted in certain reaches of the river, if the uniform flow assumption is made, while actually non-uniform flow conditions exist. This effect is quite pronounced when the flow non-uniformity results from a downstream control structure such as a weir.

Multiobjective Optimal Waste Load Allocation Models for Rivers Using Nondominated Sorting Genetic Algorithm-II

A multiobjective optimization framework for optimal waste load allocation in rivers is proposed, considering (1) the total treatment cost, (2) the equity among the waste dischargers, and (3) a comprehensive performance measure that reflects the dissolved oxygen (DO) violation characteristics. This framework consists of an embedded river water quality simulator that has a gradually varied flow module and a pollutant transport module, which simulates the transport process including reaction kinetics (in terms of biochemical oxygen demand-DO). The outer shell of the framework consists of the two nonseasonal, deterministic, multiobjective waste load allocation planning models, namely, cost-performance model and cost-equity-performance model. These models are solved using a powerful and recently developed multiobjective genetic algorithm technique known as the Nondominated Sorting Genetic Algorithm-II. The practical utility of the multiobjective framework in decision-making is illustrated through a realistic example of the Willamette River in the state of Oregon.

Wireless sensor networks: scheduling for measurement and data reporting

An optimal load allocation approach is presented for measurement and data reporting in wireless sensor networks with a single level tree network topology. The measurement problem investigated involves a measurement space, part of which can be sampled by each sensor. We seek to optimally assign sensors part of the measurement space to minimize reporting time and energy usage. Three representative measurement and reporting strategies are studied. This work is novel as it considers, for the first time, the measurement capacity of processors and assumes negligible computation time which is radically different from the traditional divisible load scheduling research to date. Aerospace applications include satellite remote sensing and monitoring and sensor networks deployed and monitored from the air.

Comment on "A novel data distribution technique for host-client type parallel applications

A paper by Nick Comino and V. Lakshmi Narasimhan is related to existing literature on divisible load scheduling theory. This includes the use of a Gantt-chart to illustrate timing relationships, basic model assumptions common to the divisible load scheduling literature, allowing time for the reporting back to the originator node of solutions the inclusion of fixed costs (charges) in the model, a proof that such load distribution can be optimized the product form solution for optimal load allocation of the first equation of page and the matrix multiplication application.

Optimal management of waste loading into a river system with nonpoint source pollutants

An optimization model, fit for practical use, to allocate COD (Chemical Oxygen Demand)-based wasteload into a river system among outfalls is developed within the framework of robust optimization (RO). Nonpoint source COD loading, estimated based on the unit loading factor to be assumed known, is treated as uncontrollable one. The total amount of expected allowable COD load from point sources is then, under all possible scenarios of uncertain input information, maximized while satisfying the constraints on in-stream COD and DO (Dissolved Oxygen) transport, effluent standards and river water quality standards. Advantage of the e-RO model using the ∈-constraint method for optimization practice is brought to light from theoretical and practical aspects, in comparison with the conventional RO model resorting to the Lagrangian method. Solving a simple hypothetical example problem, it is demonstrated that the model developed is competent for successfully generating noninferior and robust solutions on optimal COD load allocation.

Optimal time-varying load sharing for divisible loads

A load sharing problem involving the optimal load allocation of divisible loads in a distributed computing system consisting of N processors interconnected through a bus-oriented network is investigated. For a divisible lend, the workload is infinitely divisible so that each fraction of the workload can be distributed and independently computed on each processor. For the first time in divisible load theory, an analysis is provided in the case when the processor speed and the channel speed are time varying due to background jobs submitted to the distributed system with nonnegligible communication delays. A numerical method to calculate the average of the time-varying processor speed and the channel speed and an algorithm to find the optimal allocation of the workload to minimize the total processing finish time are proposed via a deterministic analysis. A stochastic analysis which makes use of Markovian queueing theory is introduced for the case when arrival and departure times of the background jobs are not known.

Information integration in computerized distribution system planning

Electricity distribution planning automation involves a great deal of information, residing in different systems. Information sharing among these systems is essential in improving the efficiency and quality of distribution system planning. This paper presents an integrated solution for computerized distribution planning in a geographic information system (GIS) context, a synergy that magnifies the data accessibility between load forecasting and feeder planning tools, sealing the traditional gap between long-term and short-term distribution system planning. A stochastic cell-based load forecasting algorithm is first developed, followed by an optimal load allocation module, NODESIM, which spatially relates the load growth to the vector-based circuit topology from feeder planning tools. NODESIM enables the multi-year distribution system studies in a GIS context, to best assist utility planners in deciding where and when the customers will grow and how to expand the system facilities to meet the demand growth.

Interactive expert system for optimal design of electricity distribution systems

An expert system to optimise the design of distribution systems is developed. The expert system is divided into three main parts. Optimising the location of substation, determining the optimal conductor layout, and obtaining the best conductor profile. An iterative procedure that improves on a user-defined initial location is employed to determine the optimal site to locate the substation. The programming approach allows the designer to choose the second best site if the optimal site is not acceptable. The heuristic search technique of best-first searching is used to determine the optimal cable layout and load allocation. The objective function developed to determine the optimum conductor profile strikes a balance between the capital cost and the cost of losses. The modular programming approach allows the design engineer to focus on any of the three sections of the design. Often the location of substations is determined by regulation. In such a situation the design engineer can adopt to optimise the conductor layout and the conductor profile of the distribution system. If the conductor sizes available fail to satisfy the user-defined constraints, the designer can rerun the conductor optimising section after making the relevant changes to the inventory database.

Optimal divisible job load sharing for bus networks

Optimal load allocation for load sharing a divisible job over N processors interconnected in bus-oriented network is considered. The processors are equipped with front-end processors. It is analytically proved, for the first time, that a minimal solution time is achieved when the computation by each processor finishes at the same time. Closed form solutions for the minimum finish time and the optimal data allocation for each processor are also obtained.

Closed form solutions for bus and tree networks of processors load sharing a divisible job

Optimal load allocation for load sharing a divisible job over processors interconnected in either a bus or a tree network is considered. The processors are either equipped with front-end processors or not so equipped. Closed form solutions for the minimum finish time and the optimal data allocation for each processor are obtained. The performance of large symmetric tree networks is examined by aggregating the component links and processors into a single equivalent processor. This allows an easy examination of large tree networks. In addition, it becomes possible to find a closed form solution for the optimal amount of data that is to be assigned to each processor in the tree network in order to achieve the minimum finish time.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Queueing network models for load balancing in distributed systems

In distributed systems, load balancing can improve efficiency by migrating jobs from heavily loaded to lightly loaded sites. In this paper we present a method for optimal load allocation in a static environment. A queueing network model is used to evaluate response time, and mathematical programming techniques are used to find the load allocation that minimizes average response time. The method is not proposed as a substitute for dynamic, heuristic load balance policies; rather, it is perceived as a useful tool for resource allocation and capacity planning in distributed systems and as a promising complement to dynamic policies in hybrid load balance strategies. The method can handle very general classes of problems, including distinct classes of jobs, multitasking within each job, and jobs with spawned tasks. Several examples illustrating these applications are reported.

Lifetime distribution of circular [formula omitted] systems with exchangeable lifetimes : Stavros G. Papastravridis. IEEE Trans. Reliab.38(4), 460 (1989)

We develop an optimal load allocation for load-sharing k-out-of-n:F systems with piecewise linear degradation models. The components are assumed non-repairable, and they are removed from the system as soon as they fail. It is shown that the lifetime of a system is maximized by allocating the load on a system to its components according to component residual lifetimes. The same allocation can be applied to the systems in which the lifetime distributions of components are known and also in which the lifetime distributions belong to a scale family, by assuming an accelerated lifetime model and the cumulative damage rule.

Outage state optimal load allocation in distribution systems under voltage drop constraints

Electrical Engineering in JapanVolume 109, Issue 5 p. 10-18 Article Outage state optimal load allocation in distribution systems under voltage drop constraints Kenichi Aoki, Kenichi Aoki Faculty of Engineering, Hiroshima UniversitySearch for more papers by this authorTaiji Satoh, Taiji Satoh Faculty of Engineering, Hiroshima UniversitySearch for more papers by this authorMasaru Itoh, Masaru Itoh Faculty of Engineering, Hiroshima UniversitySearch for more papers by this authorHeijiro Kuwabara, Heijiro Kuwabara Faculty of Engineering, Kinki UniversitySearch for more papers by this authorMasakazu Kanezashi, Masakazu Kanezashi Aichi Institute of TechnologySearch for more papers by this author Kenichi Aoki, Kenichi Aoki Faculty of Engineering, Hiroshima UniversitySearch for more papers by this authorTaiji Satoh, Taiji Satoh Faculty of Engineering, Hiroshima UniversitySearch for more papers by this authorMasaru Itoh, Masaru Itoh Faculty of Engineering, Hiroshima UniversitySearch for more papers by this authorHeijiro Kuwabara, Heijiro Kuwabara Faculty of Engineering, Kinki UniversitySearch for more papers by this authorMasakazu Kanezashi, Masakazu Kanezashi Aichi Institute of TechnologySearch for more papers by this author First published: September/October 1989 https://doi.org/10.1002/eej.4391090502Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume109, Issue5September/October 1989Pages 10-18 RelatedInformation

Fast Method for Constrained Load-allocation Strategy in Hydro-thermo-pump Electric Energy Systems

Important segments of the optimal economic dispatch problem are optimal load allocation, operation planning and expansion planning. A fast, direct calculation method Is presented using derived analytical formulae that can be applied to complex hydro thermo pump electric energy systems. An optimization technique for nonlinear cost function sub|ect to equality and Inequality constraints Is used to compute the control strategy as a sequence of power command vectors to coordinate the electricity generation plants In the system over the time period of Interest Results for an electric energy system consisting of four thermal plants, three hydraulic plants, and one pump accumulation plant are presented.

An expert system for load allocation in distribution expansion planning

The design of a rule-based expert system for load allocation in the expansion planning of a distribution system is reported. The heuristic rules followed by distribution planners are incorporated into the knowledge base using the artificial language PROLOG. Algorithms aimed at minimizing power loss, minimizing investment cost, and computing service reliability, respectively, are developed to support the inference engine to reach proper lead allocation plans. The expert system using the developed algorithms and knowledge base is built on a personal computer and is applied to reallocate some loads in a distribution system in Taiwan, which consists of three substations and twenty-eight feeders, to a substation that is expected to be operating in the near future. It is demonstrated that the expert system can yield several suitable load allocation plans and can assist the planners in reaching an optimal load allocation plan by providing valuable information. The expert system is not designed to replace the system planner. Rather, it suggests several good plans, and the final decision is left to the system planners.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Bi-objective analysis of waste load allocation using fuzzy linear programming

Because of its complexity from both a legal and economic standpoint, the problem of optimal waste load allocation is multiobjective by nature and should be treated accordingly. To perform this task, an optimization technique known as fuzzy linear programming is utilized in solving a multiple-discharge, two-objective waste load allocation problem. The two objectives considered are: (1) the maximization of waste discharge and (2) the minimization of the largest difference in equity measure between the various dischargers. Results from this study reveal that fuzzy linear programming is a valuable tool for solving the multiple-objective water quality management problems. Moreover, it is shown that the selection of a linear or logistic membership function in providing preference criteria between the two objects, has no effect on the ‘best compromising solution’.

電圧降下制約を考慮した配電系統の事故時負荷切換方法

電圧降下制約を考慮した配電系統の事故時負荷切換方法

Outage State Optimal Load Allocation by Automatic Sectionalizing Switches Operation in Distribution Systems

Outage State Optimal Load Allocation by Automatic Sectionalizing Switches Operation in Distribution Systems

Outage State Optimal Load Allocation by Automatic Sectionalizing Switches Operation in Distribution Systems

This paper presents a systematic and practical algorithm for load transfer by automatic sectionalizing switch operation in distribution systems at a fault occurrence subject to the transformer-capacity constraints and the line-capacity constraints on condition that all the section loads are estimated. The algorithm is developed by introducing the concept of subset sum problem and network structure. Computer experience with a real system indicates that the algorithm proposed here is valid and effective for practical operations.

Normal State Optimal Load Allocation in Distribution Systems

This paper addresses a subproblem related to distribution automation. It outlines an algorithm and presents computer results for minimizing the losses in a loop distribution system based on the remote operation of sectionalizing switches on feeders interconnecting different substations. The minimization is carried out subject to the voltage-drop, line-capacity and substation-capacity constraints. Computational experience with a system of realistic size indicates that the procedure proposed here is valid and effective in practical operations.