Minimal Resource Requirements Research Articles

Segregated targeting for multiple resource networks using decomposition algorithm

AbstractA generalized decomposition technique is presented for determining optimal resource usage in segregated targeting problems with single quality index (e.g., concentration, temperature, etc.) through pinch analysis. The latter problems are concerned with determining minimal resource requirements of process networks characterized by the existence of multiple zones, each consisting of a set of demands and using a unique external resource. However, all the zones share a common set of internal sources. The decomposition algorithm allows the problem to be decomposed into a sequence of subproblems, each of which can in turn be solved using any established graphical or algebraic targeting methodology to determine the minimum requirement of respective resource. This article presents a rigorous mathematical proof of the decomposition algorithm, and then demonstrates its potential applications with case studies on carbon‐constrained energy sector planning, interplant water integration, and emergy‐based multisector fuel allocation. © 2009 American Institute of Chemical Engineers AIChE J, 2010

Application of Web Services for Structural Engineering Systems

The Internet has revolutionized the way computing is done and the way software systems work. Many systems, such as search engines and PC games, have utilized Web-related technologies for Web-based systems. However, the application of Web-based engineering software is still in its infancy, especially regarding engineering computing. This paper presents a prototype development of Web-based structural engineering systems by utilizing modern computer graphics and information technology to provide Web-based analytical services. The system design emphasizes platform-independence, graphical interface, system performance, and a multiple-user environment. The user needs only an Internet-connected machine to access high-performance services provided at remote sites over the Web. This framework will provide users a powerful tool to efficiently perform analysis with minimal computer resource requirements. The user will always have access to the most up-to-date and functional system with no client-side updates or maintenance required. Two Web-based system implementations are given as examples in this paper.

Application of artificial neural networks in wastewater treatment

In the past few years, artificial neural networks (ANNs) have been used in describing and modelling wastewater treatment processes. Artificial neural network models can be identified without a detailed knowledge of the kinetics of the system to be modelled. Also, ANN models can potentially contain a great deal of information about the system itself, including the same type of information contained in conventional deterministic models. The fact that these models can be continuously updated with minimal resource requirements makes them very attractive for application in a real-time control scenario. In the current paper, applications of ANNs in the field of wastewater treatment performance prediction are reviewed. In addition, this paper presents a case study that reports some comprehensive modelling work to develop nonlinear neural network prediction models for the Gold Bar Wastewater Treatment Plant (GBWWTP), the largest sewage treatment facility in Edmonton, Alberta. Key words: wastewater treatment, artificial neural networks, flow prediction, primary sedimentation, activated sludge.

VCR-oriented video broadcasting for near video-on-demand services

A true video-on-demand (TVOD) system lets users view any video program, at any time, and perform any VCR functions, but its per-user video delivery cost is too expensive. A near video-on-demand (NVOD) is a more scalable approach by batching multiple clients to a shared stream or broadcasting videos. In order to provide subscribers with high-quality VOD service, it is desirable to add VCR functionality such as fast forward, fast backward and so on, but the existing video broadcasting, protocols have a limitation on providing VCR functionality. In this paper, we present the conditions necessary to provide VCR functions and then propose a video broadcasting scheme suitable for providing them, which satisfies these conditions, with minimal resource requirements. Since our proposed scheme receives video frames as a unit it can keep up rapidly with a changing VCR action pattern. It is demonstrated that the scheme provides VCR functionality consistently with minimal buffer space through simulations.

Providing VCR functionality in staggered video broadcasting

A true video-on-demand (TVoD) system allows users to view any video program, at any time, and perform any VCR function, but its per-user video delivery cost is very expensive. A near video-on-demand (NVoD) system uses a more scalable approach by batching multiple clients to a shared stream of broadcasting videos. Staggered video broadcasting, one of the NVoD techniques, broadcasts multiple streams of the same video at staggered times, with one stream serving multiple clients. In order to provide subscribers with a high-quality VoD service, it is desirable to add VCR functionality, such as fast forward and fast rewind, but it is not easy to provide VCR functionality in NVoD, especially a video broadcasting system where no dedicated or interactive channel is available. We analyze the conditions necessary to provide VCR functions and then propose a reception schedule that satisfies these conditions, with minimal resource requirements. Since our proposed scheme receives video frames as units, it can rapidly sustain a changing VCR action pattern. It is demonstrated, by simulation, that the scheme provides VCR functionality consistently with minimal buffer space.

The marketing of industrial real estate: application of Taguchi loss functions

AbstractThe marketing of industrial real estate is a resource‐consuming endeavour for all parties involved consisting of many objectives that, in many cases, may be in conflict with one another. One method of minimizing resource requirements, especially time, while increasing the probability of a successful match is to select properties for presentation that maximizes buyer utility. Zionts (1992) indicated one area for future research in multiple criteria decision‐making (MCDM) is in the development of ‘Eclectic Approaches’ using old ideas in a new way to help develop MCDM approaches. In this paper Taguchi loss functions, a procedure commonly used in quality control, is proposed as a tool that can be used by industrial real estate professionals to more efficiently determine the property that most closely matches the buyer's needs. Copyright © 2001 John Wiley & Sons, Ltd.

Optimal local implementation of nonlocal quantum gates

We investigate the minimal resources that are required in the local implementation of non-local quantum gates in a distributed quantum computer. Both classical communication requirements and entanglement consumption are investigated. We present general statements on the minimal resource requirements and present optimal procedures for a number of important gates, including CNOT and Toffoli gates. We show that one bit of classical communication in each direction is both necessary and sufficient for the non-local implementation of the quantum CNOT, while in general two bits in each direction is required for the implementation of a general two bit quantum gate. In particular, the state-swapper requires this maximum classical communication overhead. Extensions of these ideas to multi-party gates are presented.

A tree-search method for solving a cutting stock assignment problem

Many production environments such as carpet or flat glass manufacturing have linked operations that perform completely different activities. In this paper, we consider a two-stage manufacturing process involving a cutting operation, followed by an assignment operation. Raw material is cut to meet product demand with minimum trim loss, and assignments are made to minimize resource requirements. This cutting stock assignment problem is formulated as a large-scale, mixed-integer nonlinear programming problem. We propose a solution methodology based on decomposition and tree search heuristic strategies. We report on extensive computational experiments on a wide range of problems, and apply statistical techniques to determine significant factors. For all small-size problems tested, our method found the exact optimal solution. For practical-size problems, our method was about two orders of magnitude faster and produced solutions that were one-third better than tabu search.

Sublogarithmic Bounds on Space and Reversals

The complexity measure under consideration is $\mbox{\rm SPACE}\!\times\!\mbox{\rm REVERSALS}$ for Turing machines that are able to branch both existentially and universally. We show that, for any function $h(n)$ between $\log\log n$ and $\log n$, $\Pi_1 \mbox{\rm SPACE}\!\times\!\mbox{\rm REVERSALS} (h(n))$ is separated {}from $\Sigma_1 \mbox{\rm SPACE}\!\times\!\mbox{\rm REVERSALS} (h(n))$ as well as {}from $\mbox{\sf co}\Sigma_1 \mbox{\rm SPACE}\!\times\!\mbox{\rm REVERSALS} (h(n))$, for middle, accept, and weak modes of this complexity measure. This also separates determinism from the higher levels of the alternating hierarchy. For "well-behaved" functions h(n) between log log n and log n, almost all of the above separations can be obtained by using unary witness languages. In addition, the construction of separating languages contributes to the research on minimal resource requirements for computational devices capable of recognizing nonregular languages. For any (arbitrarily slow growing) unbounded monotone recursive function f(n), a nonregular unary language is presented that can be accepted by a \middle\ \mbox{$\Pi_1$ alternating} Turing machine in s(n) space and i(n) input head reversals, with $s(n)\cdot i(n)\in{\cal O}(\log\log n\cdot f(n))$. Thus, there is no exponential gap for the optimal lower bound on the product $s(n)\cdot i(n)$ between unary and general nonregular language acceptance---in sharp contrast with the one-way case.

Competition for Nutrients and Light in a Mixed Water Column: A Theoretical Analysis

Interactions between nutrient limitation and light limitation are fundamental for the dynamics and structure of phytoplankton communities. We investigate a model that predicts the outcome of competition for nutrients and light in a mixed water column on the basis of monoculture characteristics. Growth in monoculture leads to a steady state. The nutrient availability and light penetration in this steady state characterize the minimal resource requirements of a species. These minimal requirements not only determine monoculture growth but also the outcome of competition. We show that competition for nutrients and light can be investigated by means of a graphical isocline approach. In contrast to earlier resource-based approaches, our model predicts that it is not only the ratio of nutrient supply to light supply that matters for the outcome of competition but also their absolute supply rates. It is even possible that a species that competes successfully when there is a high or low light supply is displaced when the light supply is intermediate. Factors such as mixing depth and background turbidity also affect the composition of phytoplankton communities. Still, our model predicts that at most two species can stably coexist in a mixed water column. Hence, the spatial heterogeneity imposed by a light gradient is not sufficient to solve Hutchinson's paradox of the plankton.

MAGIC: a multiattribute declustering mechanism for multiprocessor database machines

During the past decade, parallel database systems have gained increased popularity due to their high performance, scalability, and availability characteristics. With the predicted future database sizes and complexity of queries, the scalability of these systems to hundreds and thousands of processors is essential for satisfying the projected demand. Several studies have repeatedly demonstrated that both the performance and scalability of a parallel database system are contingent on the physical layout of the data across the processors of the system. If the data are not declustered appropriately, the execution of an operation might waste system resources, reducing the overall processing capability of the system. With earlier, single-attribute partitioning mechanisms such as those found in the Tandem, Teradata, Gamma, and Bubba parallel database systems, range selections on any attribute other than the partitioning attribute must be sent to all processors containing tuples of the relation, while range selections on the partitioning attribute can be directed to only a subset of the processors. Although using all the processors for an operation is reasonable for resource intensive operations, directing a query with minimal resource requirements to processors that contain no relevant tuples wastes CPU cycles, communication bandwidth, and I/O bandwidth. As a solution, this paper describes a new partitioning strategy, multiattribute grid declustering (MAGIC), which can use two or more attributes of a relation to decluster its tuples across multiple processors and disks. In addition, MAGIC declustering, unlike other multiattribute partitioning mechanisms that have been proposed, is able to support range selections as well as exact match selections on each of the partitioning attributes. This capability enables a greater variety of selection operations to be directed to a restricted subset of the processors in the system. Finally, MAGIC partitions each relation based on the resource requirements of the queries that constitute the workload for the relation and the processing capacity of the system in order to ensure that the proper number of processors are used to execute queries that reference the relation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Dispatching-driven deadlock avoidance controller synthesis for flexible manufacturing systems

This paper develops a new method for synthesizing deadlock avoidance controllers (DACs) that realize job and machine dispatching policies of a flexible manufacturing system (FMS) into deadlock free control actions. Such controllers not only keep the FMS capable of repeating any of its operations, but also achieve a high resource utilization under any given dispatching policy. Our methodology is based on an untimed Petri net formalism. It consists of four ingredients: 1) a bottom-up approach for synthesizing a controlled production Petri net (CPPN) model of a FMS; 2) a necessary and sufficient liveness condition based on decomposition of the CPPN into controlled production subnets and the concept of minimal resource requirements; 3) a sufficient procedure to test whether the liveness condition is kept after a control action is executed; and 4) an algorithm that combines the test procedure with the given dispatching policy to generate valid and utilization maximizing control actions. We assess that this method is of polynomial time complexity and show that it results in a much larger class of controls than that of an existing deadlock avoidance scheme. >

Dispatching-Driven Deadlock Avoidance Controller Synthesis for Flexible Manufacturing Systems

This paper develops a new method for synthesizing deadlock avoidance controllers (DACs) that realize job and machine dispatching policies of a flexible manufacturing system (FMS) into deadlock free control actions. Our methodology is based on an untimed, deterministic Petri net formalism. It consists of four ingredients: (1) a bottom up approach for synthesizing a controlled production Petri net (CPPN) model of a FMS, (2) a necessary and sufficient liveness condition based on decomposition of the CPPN into production subnets and the concept of minimal resource requirements, (3) a sufficient procedure to test whether the liveness condition is kept after a control action is executed and (4) an algorithm that combines the test procedure with the given dispatching policy to generate valid and utilization maximizing control actions. Such controllers not only keep the FMS capable of repeating any of its operations, i.e., live, but also achieve a high resource utilization under any given dispatching policy.

A performance analysis of alternative multi-attribute declustering strategies

During the past decade, parallel database systems have gained increased popularity due to their high performance, scalability and availability characteristics. With the predicted future database sizes and the complexity of queries, the scalability of these systems to hundreds and thousands of processors is essential for satisfying the projected demand. Several studies have repeatedly demonstrated that both the performance and scalability of a paralel database system is contingent on the physical layout of data across the processors of the system. If the data is not declustered properly, the execution of an operator might waste resources, reducing the overall processing capability of the system. With earlier, single attribute declustering strategies, such as those found in Tandem, Teradata, Gamma, and Bubba parallel database systems, a selection query including a range predicate on any attribute other than the partitioning attribute must be sent to all processors containing tuples of the relation. By directing a query with minimal resource requirements to processors that contain no relevant tuples, the system wastes CPU cycles, communication bandwidth, and I/O bandwidth, reducing its overall processing capability. As a solution, several multi-attribute declustering strategies have been proposed. However, the performance of these declustering techniques have not previously been compared to one another nor with a single attribute partitioning strategy. This paper, compares the performance of Multi-Attribute GrId deClustering (MAGIC) strategy and Bubba's Extended Range Declustering (BERD) strategy with one another and with the range partitioning strategy. Our results indicate that MAGIC outperforms both range and BERD in all experiments conducted in this study.