• Structural Engineering and Mechanics
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• v.75 no.4
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• pp.445-454
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• 2020

Structural damage identification (SDI) is a crucial step in structural health monitoring. However, some of the existing SDI methods cannot provide enough identification accuracy and efficiency in practice. A novel whale optimization algorithm (WOA) based method is proposed for SDI by weighting modal data and flexibility assurance criterion in this study. At first, the SDI problem is mathematically converted into a constrained optimization problem. Unlike traditional objective function defined using frequencies and mode shapes, a new objective function on the SDI problem is formulated by weighting both modal data and flexibility assurance criterion. Then, the WOA method, due to its good performance of fast convergence and global searching ability, is adopted to provide an accurate solution to the SDI problem, different predator mechanisms are formulated and their probability thresholds are selected. Finally, the performance of the proposed method is assessed by numerical simulations on a simply-supported beam and a 31-bar truss structures. For the given multiple structural damage conditions under environmental noises, the WOA-based SDI method can effectively locate structural damages and accurately estimate severities of damages. Compared with other optimization methods, such as particle swarm optimization and dragonfly algorithm, the proposed WOA-based method outperforms in accuracy and efficiency, which can provide a more effective and potential tool for the SDI problem.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.7
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• pp.713-717
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• 2008

Recently, as the capacity of flash memory increases rapidly, efficient indexing methods become crucial for fast searching of a large volume of data stored in flash memory. Flash memory has its unique characteristics: the write operation is much more costly than the read operation and in-place updating is not allowed. In this paper, we propose a novel index structure that significantly reduces the number of write operations and thus supports efficient searches, insertions, and deletions. We verify the superiority of our method by performing extensive experiments.

• Journal of Computing Science and Engineering
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• v.3 no.1
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• pp.1-4
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• 2009

In a given text T of size n, we need to search for the information that we are interested. In order to support fast searching, an index must be constructed by preprocessing the text. Suffix array is a kind of index data structure. The compressed suffix array (CSA) is one of the compressed indices based on the regularity of the suffix array, and can be compressed to the $k^{th}$ order empirical entropy. In this paper we improve the lookup time complexity of the compressed suffix array by using the multi-ary wavelet tree at the cost of more space. In our implementation, the lookup time complexity of the compressed suffix array is O(${\log}_{\sigma}^{\varepsilon/(1-{\varepsilon})}\;n\;{\log}_r\;\sigma$), and the space of the compressed suffix array is ${\varepsilon}^{-1}\;nH_k(T)+O(n\;{\log}\;{\log}\;n/{\log}^{\varepsilon}_{\sigma}\;n)$ bits, where a is the size of alphabet, $H_k$ is the kth order empirical entropy r is the branching factor of the multi-ary wavelet tree such that $2{\leq}r{\leq}\sqrt{n}$ and $r{\leq}O({\log}^{1-{\varepsilon}}_{\sigma}\;n)$ and 0 < $\varepsilon$ < 1/2 is a constant.

• The Journal of the Korea Contents Association
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• v.10 no.10
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• pp.9-18
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• 2010

As digital contents become vast in quantity, it takes long time for users to search the digital contents they want, which is a problem that has arisen. Therefore, it is required to have the technology that analyzes vast digital contents and extracts the appropriate contents for users in order to provide them with contents they want. For a fast searching of digital contents suitable for users, it is necessary to have the technology of filtering for digital contents. In this paper, we propose a method of filtering digital contents suitable for individual users. The method suggested in this paper is to analyze case-based information in digital contents and provide the digital contents suitable for individual users. The case for using digital contents is used for analysis of users' preference. Various simulations were conducted to confirm the effectiveness of the proposed method.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.346-349
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• 2007

In this paper, the integrated search system made for the web news and review retrieval service is introduced. We made XSLTRobot that extract title, date, author and content from html document like news or reviews for search service. XSLTRobot used the XSLT technology in order to extract desired part of html page. The Intergrated Information Retrieval System(IIRS) is suitable for various search data format. And we introduce Dynamic Index Storage which is module of IIRS. Dynamic Index Storage is used to environment which needs fast index update like news. And it's design focused on retrieval performance because there was not many document that it has to update on a real time.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.324-329
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• 2005

Dynamic Encoding Algorithm for Searches (DEAS) which is known as a fast and reliable non-gradient optimization method, was proposed [1]. DEAS reaches local or global optimum with binary strings (or binary matrices for multi-dimensional problem) by iterating the two operations; bisectional search (BSS) and unidirectional search (UDS). BSS increases binary strings by one digit (i.e., 0 or 1), while UDS performs increment or decrement of binary strings in the BSS' result direction with no change of string length. Because the interval of UDS exponentially decreases with increment of bit string length (BSL), DEAS is difficult to escape from local optimum when DEAS falls into local optimum. Therefore, this paper proposes hopping UDS (HUDS) which performs UDS by hopping as many as BSL in the final point of UDS process. HUDS helps to escape from local optimum and enhances a probability searching global optimization. The excellent performance of HUDS will be validated through the well-known benchmark functions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1671-1678
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• 2006

A real time system realization for binocular eyeball tracking mouse on the computer monitor being far from 30-40cm is presented in the paper. The processing for searching eyeball and tracking the cursor are that a facial image is acquired by the small CCD camera, convert it into binary image, search for the eye two using the five region mask method in the eye surroundings and the side four points diagonal positioning method is searched the each iris. The tracking cursor is matched by measuring the iris central moving position. The cursor controlling is achieved by comparing two related distances between the iris maximum moving and the cursor moving to calculate the moving distance from gazing position and screen. The experimental results show that the binocular eyeball mouse system is simple and fast to be real time.

• ETRI Journal
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• v.38 no.3
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• pp.518-528
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• 2016

The searching of an extensive document database for documents that are locally similar to a given query document, and the subsequent detection of similar regions between such documents, is considered as an essential task in the fields of information retrieval and data management. In this paper, we present a framework for such a task. The proposed framework employs the method of short-read mapping, which is used in bioinformatics to reveal similarities between genomic sequences. In this paper, documents are considered biological objects; consequently, edit operations between locally similar documents are viewed as an evolutionary process. Accordingly, we are able to apply the method of evolution tracing in the detection of similar regions between documents. In addition, we propose heuristic methods to address issues associated with the different stages of the proposed framework, for example, a frequency-based fragment ordering method and a locality-aware interval aggregation method. Extensive experiments covering various scenarios related to the search of an extensive document database for documents that are locally similar to a given query document are considered, and the results indicate that the proposed framework outperforms existing methods.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.56
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• pp.29-54
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• 2012

As market is more and more mature, the survival environment of exporting companies is getting severer, which throws exporting companies into great pressures of the process of growth and development. For most businessmen, the hardest part of starting a foreign business is to find buyers or to get customers, which is more critical for small and medium-size foreign enterprises. The fast changes of internal and external trade and market circumstances, together with the advent of e-commerce, led to the diversified of the way to find foreign buyers for exporting companies. But the performance differs in using different ways of finding foreign buyers. Therefore, this study examines the status of the methods of finding foreign buyers and performance of exporting companies in China. Based on the investigation of the ways of finding foreign buyers, this study tries to find out the most efficient ways of finding foreign buyers for them. And this study tries to propose some practical suggestions for the exporting companies based on the analysis that will help them to improve companies' performances.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.779-784
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• 2008

An environment of information sharing is developed as a high-speed growth of internet infrastructure and a fast supply of digital imaging devices. Therefore, developing and supply various digital contents are needed. As occasion demands, the utility of editing tools with a simple image viewer, or programs to need technical education increased. One of subproblems is to take long time for editing images. In this paper, we propose a new method which is a method to edit images in a lump. This method has advantages compared with the previous searching engines in terns of performances and speed. Also, we propose the new approach for developing fusion graphic image contents as binding each advantages of the category. It reduces the production time and costs of contents by the proposed method.