An editorial about algorithms in cognition, informatics and logic is presented. The authors explain the traditional view of an algorithm A. They emphasize that the algorithm is not a portion of the declarative intrins...
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An editorial about algorithms in cognition, informatics and logic is presented. The authors explain the traditional view of an algorithm A. They emphasize that the algorithm is not a portion of the declarative intrinsic nature of the entity it serves. They consider the debate in artificial intelligence on procedural versus declarative representation.
algorithms for the computation of two-dimensional transfer functions from state-space configurations are derived. The principal steps in the programming procedure are provided.
algorithms for the computation of two-dimensional transfer functions from state-space configurations are derived. The principal steps in the programming procedure are provided.
A method of data acquisition and data analysis is described in which the performance of Michelson-type interferometers with unequal arms can be made nearly the same as interferometers with equal arms. The method requi...
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A method of data acquisition and data analysis is described in which the performance of Michelson-type interferometers with unequal arms can be made nearly the same as interferometers with equal arms. The method requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam. Instead of throwing away the information from a single arm by subtracting it from that from the other arm, the data in one arm is first used to estimate the laser phase noise and then correct for its effect in the normal differenced interferometer data.
Flash memory is a type of electrically-erasable programmable read-only memory (EEPROM). Because flash memories are nonvolatile and relatively dense, they are now used to store files and other persistent objects in han...
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Flash memory is a type of electrically-erasable programmable read-only memory (EEPROM). Because flash memories are nonvolatile and relatively dense, they are now used to store files and other persistent objects in handheld computers, mobile phones, digital cameras, portable music players, and many other computer systems in which magnetic disks are inappropriate. Flash, like earlier EEPROM devices, suffers from two limitations. First, bits can only be cleared by erasing a large block of memory. Second, each block can only sustain a limited number of erasures, after which it can no longer reliably store data. Due to these limitations, sophisticated data structures and algorithms are required to effectively use flash memories. These algorithms and data structures support efficient not-in-place updates of data, reduce the number of erasures, and level the wear of the blocks in the device. This survey presents these algorithms and data structures, many of which have only been described in patents until now.
Several algorithms for generating curved surfaces are presented, in which the difference between the sum of displayed intensities and the sum of computed intensities is distributed to the next pixel along a Hilbert cu...
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Several algorithms for generating curved surfaces are presented, in which the difference between the sum of displayed intensities and the sum of computed intensities is distributed to the next pixel along a Hilbert curve. This method improves the smoothness of images by reducing the Mach Band effect, which is related to a sudden change of intensities. A Hilbert path is found by recursively subdividing the image space.
Pipework drawings produced by CAD systems can be used as graphical input for calculation programs. This paper describes algorithms to construct a calculation model from the graphical description of a pipework network ...
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Pipework drawings produced by CAD systems can be used as graphical input for calculation programs. This paper describes algorithms to construct a calculation model from the graphical description of a pipework network and then how the model is used. The direction of flow in the network may be deduced from the overall network configuration. The model allows the calculations commonly performed during design to be carried out automatically.
Existing algorithms for solving unconstrained optimization problems are generally only optimal in the short term, It is desirable to have algorithms which are long-term optimal. To achieve this, the problem of computi...
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Existing algorithms for solving unconstrained optimization problems are generally only optimal in the short term, It is desirable to have algorithms which are long-term optimal. To achieve this, the problem of computing the minimum point of an unconstrained function is formulated as a sequence of optimal control problems. Some qualitative results are obtained from the optimal control analysis. These qualitative results are then used to construct a theoretical iterative method and a new continuous-time method for computing the minimum point of a nonlinear unconstrained function. New iterative algorithms which approximate the theoretical iterative method and the proposed continuous-time method are then established. For convergence analysis, it is useful to note that the numerical solution of an unconstrained optimization problem is none other than an inverse Lyapunov function problem. Convergence conditions for the proposed continuous-time method and iterative algorithms are established by using the Lyapunov function theorem.
Printers usually generate a limited number of colors and lack the ability of producing continuous-tone color images. Traditional error-diffusion algorithms are used to solve this problem. Compared with other approache...
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Printers usually generate a limited number of colors and lack the ability of producing continuous-tone color images. Traditional error-diffusion algorithms are used to solve this problem. Compared with other approaches, the approaches of using error-diffusion in general can generate halftoned images of better quality. However, smeared edges and textures may occur in these halftoned images. To produce halftoned images of higher quality, these artifacts due to unstable images, dot-overlap, and error-diffusion must be eliminated or reduced. In this paper, we show that unstable images can be eliminated or reduced through using a proper color difference formula to select the reproduction colors even vector error-diffusion is performed in the RGB domain. We also present a method of using different filters to halftone different components of a color. This approach may have clearer and sharper edges for halftoned color images. Unexpected colors may be generated due to dot-overlap in the printing process. We have presented a method to eliminate this color distortion in the process of error-diffusion. Halftorting a color image by our proposed error-diffusion algorithm with edge enhancement has the following characteristics: the unstable images do not exist;the color-error caused by dot-overlap is corrected;and the smeared edges are sharpened. (C) 2003 Elsevier Inc. All rights reserved.
The Chinese postman problem on mixed networks (MCPP), is a practical generalization of the classical Chinese postman problem (CPP), which has many real-world applications. The MCPP has been shown to be NP-complete. Th...
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The Chinese postman problem on mixed networks (MCPP), is a practical generalization of the classical Chinese postman problem (CPP), which has many real-world applications. The MCPP has been shown to be NP-complete. Therefore, it is difficult to solve the problem exactly. For this reason, heuristic solution procedures have been proposed to solve the problem approximately. In this paper, we first review two existing solution procedures proposed by Edmonds and Johnson [Math. Progr. 5, 88-124 (1973)], and Frederickson [J. Assoc. Comput. Mach. 26, 538-554 (1979)], then introduce two new algorithms to solve the MCPP near optimally. The proposed new algorithms are tested and compared with the existing solution procedures. Computational results showed that the two new algorithms significantly outperformed the existing solution procedures.
The process of categorizing packets into "flows" in an Internet router is called pocket classification. All packets belonging to the same flow obey a predefined rule and are processed in a similar manner by ...
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The process of categorizing packets into "flows" in an Internet router is called pocket classification. All packets belonging to the same flow obey a predefined rule and are processed in a similar manner by the router. For example, all packets with the same source and destination IP addresses may be defined to form a flow. Packet classification is needed for non-best-effort services, such as firewalls and quality of service;services that require the capability to distinguish and isolate traffic in different flows for suitable processing. In general, packet classification on multiple fields is a difficult problem. Hence, researchers have proposed a variety of algorithms which, broadly speaking, can be categorized as basic search algorithms, geometric algorithms, heuristic algorithms, or hardware-specific search algorithms. In this tutorial we describe algorithms that are representative of each category, and discuss which type of algorithm might be suitable for different applications.
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