In addition to improving the allocative efficiency of water use, water markets may reduce irrigation-related water quality problems. This potential benefit is examined with a nonlinear programming model developed to s...
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In addition to improving the allocative efficiency of water use, water markets may reduce irrigation-related water quality problems. This potential benefit is examined with a nonlinear programming model developed to simulate agricultural decision-making in a drainage problem area in California's San Joaquin Valley. Results indicate that a 30% drainage goal is achievable through improvements in irrigation practices and changes in cropping patterns induced by a water market. Although water markets will not generally achieve a least-cost solution, they may be a practical alternative to economically efficient, but informationally intensive, environmental policies such as Pigouvian taxes.
The paper presents a micro-econometric model of capital utilization and retirement. Estimates of a firm's discrete decision problem with regard to an existing piece of capital-whether to operate, hold idle or reti...
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The paper presents a micro-econometric model of capital utilization and retirement. Estimates of a firm's discrete decision problem with regard to an existing piece of capital-whether to operate, hold idle or retire it-are obtained, in the context of the U.S. cement industry, by solving a discrete-choice stochastic dynamic programming model. The estimates are then used to simulate the effects of product and input price changes, and changes in the size and age of a cement kiln on a firm's propensity to operate, hold idle and retire a kiln.
Presents mathematical programming models for linear discriminant analysis. Applications of the models; Pathologies inherent in several of the models; Functions of discriminant analysis.
Presents mathematical programming models for linear discriminant analysis. Applications of the models; Pathologies inherent in several of the models; Functions of discriminant analysis.
Focuses on problems that may appear in mathematical programming models for linear discriminant analysis. History of the development of the discriminant analysis method; Problems involved in the analysis method's c...
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Focuses on problems that may appear in mathematical programming models for linear discriminant analysis. History of the development of the discriminant analysis method; Problems involved in the analysis method's choice of objective; Existence of unbounded solutions in discriminant analysis.
Finding a parallel architecture adapted to a given class of algorithms is a central problem for architects. This paper presents a methodology to realize it, and provides an illustration using image analysis. First, we...
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Finding a parallel architecture adapted to a given class of algorithms is a central problem for architects. This paper presents a methodology to realize it, and provides an illustration using image analysis. First, we show a set of common basic operations that can be used to solve most image analysis problems. Then these movements are translated to fit some natural communications in a given architecture. The considered data movements (global operations on connected pixel sets) can express a large class of algorithms. Their implementation on exemplary massively parallel architectures (arrays, hypercubes, pyramids) is discussed.
In this paper, a survey of some packet-switched routing methods for massively parallel computers is presented. Some of the techniques are applicable to both shared-memory and message-passing architectures. These routi...
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In this paper, a survey of some packet-switched routing methods for massively parallel computers is presented. Some of the techniques are applicable to both shared-memory and message-passing architectures. These routing methods are compared in terms of their efficiency in mapping to parallel machines, network delays and interconnection topologies, deadlock and livelock freedom, and adaptivity to network congestion.
The exact likelihood function for a prototypal job search model is analyzed. The optimality condition implied by the dynamic programming framework is fully imposed. Using the optimality condition allows identification...
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The exact likelihood function for a prototypal job search model is analyzed. The optimality condition implied by the dynamic programming framework is fully imposed. Using the optimality condition allows identification of an offer arrival probability separately from an offer acceptance probability. The estimation problem is nonstandard. The geometry of the likelihood function in finite samples is considered, along with asymptotic properties of the maximum likelihood estimator.
The shared use of general-purpose uniprocessors is examined. Support for common uniform-memory-access architectures that have all memory equidistant from all processors in terms of access time is emphasized. This work...
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The shared use of general-purpose uniprocessors is examined. Support for common uniform-memory-access architectures that have all memory equidistant from all processors in terms of access time is emphasized. This work is also applicable to non-uniform-memory-access machines, whose memory access times depend on the physical distance between the processor and the accessed memory, but it does not provide a complete solution to load-balancing problems for this class of machine. The discussion covers time-sharing scheduling, the Mach scheduler, programming models, scheduling concurrency support, processor allocation, and related work
There are two distinct types of MIMD (Multiple Instruction, Multiple Data) computers: the shared memory machine, e.g. Butterfly, and the distributed memory machine, e.g. Hypercubes, Transputer arrays. Typically these ...
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There are two distinct types of MIMD (Multiple Instruction, Multiple Data) computers: the shared memory machine, e.g. Butterfly, and the distributed memory machine, e.g. Hypercubes, Transputer arrays. Typically these utilize different programming models: the shared memory machine has monitors, semaphores and fetch-and-add; whereas the distributed memory machine uses message passing. Moreover there are two popular types of operating systems: a multi-tasking, asynchronous operating system and a crystalline, loosely synchronous operating system.
In this paper I firstly describe the Butterfly, Hypercube and Transputer array MIMD computers, and review monitors, semaphores, fetch-and-add and message passing; then I explain the two types of operating systems and give examples of how they are implemented on these MIMD computers. Next I discuss the advantages and disadvantages of shared memory machines with monitors, semaphores and fetch-and-add, compared to distributed memory machines using message passing, answering questions such as “is one model ‘easier’ to program than the other?” and “which is ‘more efficient‘?”. One may think that a shared memory machine with monitors, semaphores and fetch-and-add is simpler to program and runs faster than a distributed memory machine using message passing but we shall see that this is not necessarily the case. Finally I briefly discuss which type of operating system to use and on which type of computer. This of course depends on the algorithm one wishes to compute.
Consider the problem of allocating two treatments in a sequence of N trials such that the total expected reward is maximized. We assume that the distribution of outcomes is known for one of the treatments only (so-cal...
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Consider the problem of allocating two treatments in a sequence of N trials such that the total expected reward is maximized. We assume that the distribution of outcomes is known for one of the treatments only (so-called one-armed bandit problem). In a suitable dynamic programming model we examine the structural properties of an optimal policy. In particular we extend results known for Bernoulli distributed outcomes to more general distributions. Our main technical results are monotonicity and convexity of the total expected reward.
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