Spent zircaloy cladding and channel boxes from Boiling Water Reactors (BWR), which constitute spent zircaloy waste, are not recycled in spent fuel reprocessing plants. The zircaloy waste should be pressed and packed i...
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Similarity-based search over time-series databases has been a hot research topic for a long history, which is widely used in many applications, including multimedia retrieval, data mining, web search and retrieval, an...
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ISBN:
(纸本)9781595936493
Similarity-based search over time-series databases has been a hot research topic for a long history, which is widely used in many applications, including multimedia retrieval, data mining, web search and retrieval, and so on. However, due to high dimensionality (i.e. length) of the time series, the similarity search over directly indexed time series usually encounters a serious problem, known as the "dimensionality curse". Thus, many dimensionality reduction techniques are proposed to break such curse by reducing the dimensionality of time series. Among all the proposed methods, only Piecewise Linear Approximation (PLA) does not have indexing mechanisms to support similarity queries, which prevents it from efficiently searching over very large time-series databases. Our initial studies on the effectiveness of different reduction methods, however, show that PLA performs no worse than others. Motivated by this, in this paper, we re-investigate PLA for approximating and indexing time series. Specifically, we propose a novel distance function in the reduced PLA-space, and prove that this function indeed results in a lower bound of the Euclidean distance between the original time series, which can lead to no false dismissals during the similarity search. As a second step, we develop an effective approach to index these lower bounds to improve the search efficiency. Our extensive experiments over a wide spectrum of real and synthetic data sets have demonstrated the efficiency and effectiveness of PLA together with the newly proposed lower bound distance, in terms of both pruning power and wall clock time, compared with two state-of-the-art reduction methods, Adaptive Piecewise Constant Approximation (APCA) and Chebyshev Polynomials (CP). Copyright 2007 VLDB Endowment, ACM.
In order to assist driver's vision, a real-time recognition system for traffic signs is proposed. After detecting sign candidates, biologically inspired opponent-color filters are used to extract symbol parts of s...
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ISBN:
(纸本)9781617387777
In order to assist driver's vision, a real-time recognition system for traffic signs is proposed. After detecting sign candidates, biologically inspired opponent-color filters are used to extract symbol parts of signs. After normalizing the size of symbol, structural features are calculated to identify the sign. 5572 segmented images are used to design the algorithm. In a real-time system, the same sign in a sequence of frames is tracked, and a majority vote is used to integrate the recognition results. For test data, 93.8% recall rate and 99.3% precision rate could be attained. In-vehicle experiment also showed high recall and precision rates.
This study focuses on the mathematical modeling of the optimal spare capacity assignment problem for the links of a telecommunications network. Given a network topology, a point-to-point demand matrix with demand rout...
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This study focuses on the mathematical modeling of the optimal spare capacity assignment problem for the links of a telecommunications network. Given a network topology, a point-to-point demand matrix with demand routings, and the permissible values for link capacity, we optimize the assignment of spare capacity to the links of the network in order for it to survive single link failures. The modular spare capacity allocation problem is formulated as a mixed-integer program which is computationally expensive for all but small problem instances. To be able to solve large practical problem instances, we strengthen the continuous relaxation by including additional constraints related to cuts in the network topology graph. Our solution approach is to decompose the problem into a pair of smaller problems for which optimal solutions can be obtained within a realistic time constraint. Combining the solutions for the subproblems results in a feasible solution for the original problem. We analyze the efficiency of cut-generating techniques used to derive additional constraints, and we empirically investigate the performance of the decomposition approach. The numerical results indicate that the combination of additional constraints and the decomposition algorithm improves solution times when compared to solving the original mixed-integer program. The solution time improvement using the proposed heuristics can be as high as an order of magnitude for small problem instances, while large practical problem instances can be solved in less than half the time.
Existing vision substitute systems have insufficient spatial resolution to provide environmental information. To present detailed spatial information, we propose a stimulation method to present the target range accura...
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Experience from past single-system integration programs dictates the importance of disciplined and effective interface management in a program's execution of systemsengineering process. System-of-systems (SoS) in...
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Experience from past single-system integration programs dictates the importance of disciplined and effective interface management in a program's execution of systemsengineering process. System-of-systems (SoS) integrations are substantially more challenging than single-systems integrations due to the complexity and sheer number of the interfaces involved. The interfaces are recognized as a major risk area for SoS development programs. Classical systemsengineering processes must be modified to mitigate these risks. This paper will give an overview of SoS interface management as implemented on the US Army's Future Combat systemsprogram. This paper will identify how processes and teams have been emplaced to ensure effective and disciplined interface management on this SoS program.
The impact of reliability growth on repairable inventory management is discussed and analyzed. A stochastic inventory optimization model is proposed to minimize the repair and delivery costs for defective parts consid...
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The impact of reliability growth on repairable inventory management is discussed and analyzed. A stochastic inventory optimization model is proposed to minimize the repair and delivery costs for defective parts considering the reliability growth and the increase of product installation in the field. Crow/AMSAA model is used to estimate the reliability growth trends: homogeneous Poisson failures (HPP) vs. non-homogenous Poisson failures (NHPP), based on which the demand for spare products is forecasted with the consideration of new product installation rate. To obtain the repair rate estimate for defective parts, the uncertainty of transition time to the repair center and the failure modes are appropriately combined using the central limit theorem, based on which the mean and the standard deviation of the repair rate are estimated. Given the reliability growth rate and the stochastic repair rate, an optimization is formulated to minimize the repair cost while subject to the requirement of the service quality index. Finally the proposed inventory optimization model is demonstrated on a type of semiconductor test equipment.
Complex watershed models with decision support systems (DSS) have been developed to aid in integrated water resources management (IWRM) and sustainable water supply planning. Detailed simulation models are important i...
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Complex interactions among components of a watershed system necessitate the evaluation of management options within a watershed framework in order to realize the full impact of management decisions. A generic optimiza...
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