• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.1
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• pp.120-124
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• 1998

Tn the analysis of the audio signal characteristices and the codebook indices of LD-CELP, there are many cases of detecting codebook indices that are used previous. LD-CELP algorithm achives good quality of audio because it has analyzed a short term of audio signal. In spite of these advantage, the method has a drawback in which searching time of best codebook index inclose due to a complicated calculation for codebook index. This paper is proposed to decreasing the searching time of codebook index using a searching memory. As a simulation of the proposed method, searching time for codebook index is reduced 3.2%-11.7% as compared with LD-CELP.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.12
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• pp.83-89
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• 2008

Simple but effective fast codebook searching algorithms for quantized EGT(equal gain transmission) are presented. Using newly defined metric, rough searching selects a few candidate weight vectors. Using the conventional metric, accurate searching determines the optimal vector among the candidates. This strategy reduces the entire searching time. When the number of transmit antenna is two or three, the searching time reduces more than a half less than the conventional searching time. Moreover, the more the size of codebook increases, the more the searching time reduction also increases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1986-1992
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• 2009

A user often searches a data by inputting a variant such as the abbreviation or substring of a word, or a misspelled word. The simple approach to the searching for variants is to build a variants dictionary. However, it entails enormous cost and time and can not handle variants by misspelling. Approximate searching, searching by approximate string matching, is a good approach to the searching. A problem in the approach is that it cannot handle variants by abbreviations. This paper propose a method for searching various variants including abbreviations and misspelled words, by using the trie indexing. First, this paper shows a variant matching method with the calculation of path weighted-metric. In addition, it provides variant searching algorithm to reduce the search time.

• Journal of KIISE:Databases
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• v.36 no.1
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• pp.44-49
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• 2009

In recent years, with the development of portable terminals, various searching services on large data have been provided in portable terminals. In order to search large data, most applications for information retrieval use indexes such as B-trees or R-trees. However, only a small portion of the data set is accessed by users, and the access frequencies of each data are not uniform. The existing indexes such as B-trees or R-trees do not consider the properties of the skewed access patterns. And a cache stores the frequently accessed data for fast access in memory. But the size of memory used in the cache is restricted. In this paper, we propose a new index based on disk, called J-tree, which considers user's search patterns. The proposed index is a balanced tree which guarantees uniform searching time on all data. It also supports fast searching time on the frequently accessed data. Our experiments show the effectiveness of our proposed index under various settings.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.1
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• pp.98-105
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• 2011

Reduced complexity codebook searching for Quantized Equal Gain Transmission(QEGT) is proposed over MIMO-OFDM systems. QEGT codebook is divided into M groups of Q index members. Each group has a representative index. At the 1st stage only the representative indices are searched then the best index is selected. At the 2nd stage the optimum index is determined only among the group of the selected representative index. This strategy reduces the overall index search algorithm comparing to the conventional methods. Monte-Carlo simulation shows that the searching complexity is reduced, but the link-level performance is still almost the same as the conventional methods when the number of transmission antennas are 3 to 7.

• Journal of the Korea Society of Computer and Information
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• v.14 no.7
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• pp.89-95
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• 2009

This paper proposes a tag indexing scheme for RFID tag using spatial index. The tag being used for the inventory management and the tag's location is determined by the position of readers. Therefore, the reader recognizes the tag, which is attached products and thereby their positions can be traced down. In this paper, we propose hTag-tree( Hybrid Tag index) which manages RFID tag attached products. hTag-tree is a new index, which is based on tag's attributes with fast searching, and this tag index manages RFID tags using reader's location. This tag index accesses rapidly to tags for insertion, deletion and updating in dynamic environment. This can minimize the number of node accesses in tag searching comparing to previous techniques. Also, by the extension of MER in present tag index, it is helpful to stop the lowering of capacity which can be caused by parent node approach. The proposed index experiment deals with the comparison of tag index. Fixed Interval R-tree, and present spatial index, R-tree comparison. As a result, the amount of searching time is significantly shortened through hTag-tree node access in data search. This shows that the use of proposed index improves the capacity of effective management of a large amount of RFID tag.

• Journal of the Korean Society for information Management
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• v.6 no.2
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• pp.69-85
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• 1989

This study aims at reviewing the manual searching and the on-line Searching one of literature at the library or the information center, based on the comparative cost-effectiveness analysis. For this purpose, the two literature searching modes, the MEDLINE database and the corresponding Index Medicos one were used at the Medical school library of the‘s’university under same conditions of using six requests.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.7
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• pp.640-650
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• 1991

In the paper, the threepoint search algorithm used direct search method for optimal design is proposed. Proposed algorithm is composed of two iteration procedure to determine the minimum value of performance index. The minumum value of three-point existing in the inner N-order searching is firstly determined and next searching space is then reduced by the result of first procedure. To compute performance index. 3N iteration for a searching is necessary. 3N searching method is also described and confirmed with exception of parameter included multiphicator and divisor. Proposed algorithm have good stability and reliability when performance index is linear or quadratic function.

• The KIPS Transactions:PartD
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• v.11D no.5
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• pp.1003-1010
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• 2004

In this paper, we address efficient processing of subsequence matching in time-series databases. We first point out the performance problems occurring in the index searching of a prior method for subsequence matching. Then, we propose a new method that resolves these problems. Our method starts with viewing the index searching of subsequence matching from a new angle, thereby regarding it as a kind of a spatial-join called a window-join. For speeding up the window-join, our method builds an R＊-tree in main memory for f query sequence at starting of sub-sequence matching. Our method also includes a novel algorithm for joining effectively one R＊-tree in disk, which is for data sequences, and another R＊-tree in main memory, which is for a query sequence. This algorithm accesses each R＊-tree page built on data sequences exactly cure without incurring any index-level false alarms. Therefore, in terms of the number of disk accesses, the proposed algorithm proves to be optimal. Also, performance evaluation through extensive experiments shows the superiority of our method quantitatively.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.1
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• pp.62-69
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• 2011

A novel QEGT codebook index searching algorithm for long tenn evolution (LTE) system is proposed. The proposed algorithm divides the Q precoding vectors into M groups, and selects the optimal precoding vector from the selected group at the receiver. This algorithm reduced the calculation for searching the optimal precoding vector index compared to the previous algorithms. The index searching algorithm is implemented for TI's TMS320C6713 DSP board. When the number of transmit antenna is 4, the number of clock cycles is reduced to 25%.