• The Transactions of the Korea Information Processing Society
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• v.6 no.10
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• pp.2597-2607
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• 1999

In this paper, we propose an efficient large item generation algorithm that overcomes the problem of the existing algorithm for making large items from quantitative attributes. The proposed algorithm splits dataset into variable size of intervals by min_split_support and merges the intervals according to the support of each interval. It reflects characteristic of data to generated large items and can generate finer large items than the existing algorithm. It is shown through the performance evaluation that our proposed algorithm outperforms the existing algorithm.

• KSCI Review
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• v.2 no.1
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• pp.130-139
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• 1995

This paper suggests the method to shorten the search area by using edge detection and subimage partition. For the purpose reduce encoding time, The Domain areas are reduced 1/64 by partitioning original image to subimage, and classified them into edge area and shade area so that detect only the area in the same class. for achieving an encoding with good fidelity, tried to differ the search method as the threshold value of edge which is included in subimage, and compared the compression rate and fidelity when set the size of range block as $4{\times}4$ and $8{\times}8$.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.6
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• pp.565-574
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• 2002

We propose an algorithm for the robust transmission of video in error prone environment based on multiple description (MD) scheme and simple rate-distortion operators. The redundancy rate-distortion (RRD) criteria is used to split a one-layer compressed video stream into two correlated descriptions. The proposed algorithm can find more candidate points on the RRD curve than the conventional RRD based methods. A new distortion measure is also defined in this paper, which considers more realistic error environments. Since the proposed MD video coder is based on the standard H.263 coder, each description can be decoded independently by the standard H.263 decoder. Also, several descriptions can be decoded into a single stream by additional merge stage and the H.263 decoder. Simulation results show that the proposed MD video coder yields better performance than the conventional MD splitting algorithm at all bitrates both in single and two description cases.

• Radiation Oncology Journal
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• v.12 no.1
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• pp.9-16
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• 1994

Hypothesis that hypoxic tumors should be more responsive to the addition of preferential hypoxic cell cytotoxin SR 4233 (tirapazamine) to fractionated irradiation was tested in the mouse SCCVll carcinoma and RIF-1 sarcoma, Model of hypoxic tumor was established using the tumor bed effect: tumors growing in the preirradiated tissue (preirradiated tumors) were more hypoxic than tumors growing in the unirradiated tissue (unirradiated tumors). When the tumors reached a mean volume of 100 $mm^{3}$, both unirradiated and preirradiated tumors were treated with a fractionated course of 6${\times}$2 Gy in 3 days or 8${\times}$2.5 Gy in 4 days with SR 4233 (0.08 mmol/kg/injection) given 30 minutes before each irradiation or without SR 4233. Compared to the unirradiated tumors, hypoxic preirradiated tumors were approximately 5 times more resistant to fractionated irradiation alone but were approximately 5 times more responsive to SR 4233. Addition of SR 4233 Potentiated the effect of fractionated irradiation in both unirradiated and preirradiated tumors. Potentiation in the preirradiated tumors was morequal to or greater than that in the unirradiated tumors and seemed to be higher for more fractionated treatment. We confirm the hypothesis in a transplantable mouse tumor. Present results suggest that radioresistance of some hypoxic tumors can be overcome with hypoxic cytotoxin.

• The Journal of the Acoustical Society of Korea
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• v.12 no.5
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• pp.5-13
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• 1993

본 논문에서는 음성신호의 시간정보와 상관성을 포함할 수 있는 방법으로 시퀀스-피이드백 신경회로망을 제안하였으며, 그에 의한 단어인식을 수행하였다. 이 방법에서는 음성을 인식할 때 순차적으로 과거의 출력을 네트워크 입력으로 피이드백시켜 신경회로망으로 하여금 음성의 상관성과 시간정보를 갖도록 하는 순차적인 피이드백 순환구조의 시퀀스-bldlemqor 신경회로망을 이용하였으며 시퀀스-bldlemqor 신경회로망의 입출력층의 수를 줄이는 방법으로 등분 분할을 사용하였다. 본 논문에서 제안한 방법으로 한국어 숫자음을 대상으로 실험한 결과 92.5%의 인식율을 얻었으며, 피이드포워드형 신경회로망에서의 옷인식율을 1/3배 정도로 감소시켰다.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11a
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• pp.275-278
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• 2003

자동차 번호판 인식 시스템은 영상획득, 번호판추출, 전처리(이진화), 문자영역 분할, 문자인식 등의 5가지 핵심 부분으로 구성된다. 따라서 자동차 번호판 인식 시스템의 최종 인식율은 각 단계의 성능에 따라 직접적인 영향을 받는다. 본 논문은 영상처리 기법을 이용하여 영상에서 번호판 영역을 추출을 위한 연구로 문자인식 단계에서 높은 인식율을 확보할 수 있도록 빠른 연산속도와 추출 정확성을 높일 수 있는 알고리즘을 제안한다.

• Proceedings of the Korea Society for Simulation Conference
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• 2000.04a
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• pp.7-11
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• 2000

본 연구에서는 다품종 수주생산형 장치산업에서 대 Lot의 분할생산, Lot간 setup을 포함하는 Loss time의 감축, 납기현실화, 선별적 수주정책 등 다양한 수주 및 생산정책을 평가하는 확정적 시뮬레이션 모형을 개발하였다. 평가기준으로는 수주일부터 생산일까지의 대기일과 납기준수율을 사용하였다. 사례연구로 A화학공장의 1999년도 수주데이타를 입력자료로 사용하여 모형의 타당성을 보이고 납기단축 및 납기준수율 제고를 위한 효과적인 대안을 도출하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11C
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• pp.673-681
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• 2011

In this paper, we design multiple antenna relay transmission schemes of low complexity to enhance the spatial diversity in orthogonal frequency division multiplexing (OFDM) systems. The relay scheme underlined, can provide space time block coding (STBC) of OFDM signals in the time domain without IFFT and FFT operations with much reduced complexity. In this paper, we modify the conventional low-complexity STBC-OFDM relaying scheme to be compatible to the existing OFDM systems. In addition, we extend the proposed scheme for multiple antenna relays and provide performance enhancement strategies according to the channel quality information available at the relay. The proposed scheme is shown to improve the diversity and thereby to reduce the outage probability and coded bit error rate. Therefore, the proposed scheme will be promising for service quality improvement or coverage extension based on OFDM like wireless LANs and maritime communications.

• Journal of KIISE:Databases
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• v.30 no.1
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• pp.80-94
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• 2003

In this paper. we propose an enhanced concurrency control algorithm that minimizes the query delay efficiently. The factors that delay search operations and deteriorate the concurrency of index structures are node splits and MBR updates in multi dimensional index structures. In our algorithm, to reduce the query delay by split operations, we optimize exclusive latching time on a split node. It holds exclusive latches not during whole split time but only during physical node split time that occupies small part of whole split time. Also to avoid the query delay by MBR updates we introduce partial lock coupling(PLC) technique. The PLC technique increases concurrency by using lock coupling only in case of MBR shrinking operations that are less frequent than MBR expansion operations. For performance evaluation, we implement the proposed algorithm and one of the existing link technique-based algorithms on MIDAS-III that is a storage system of a BADA-III DBMS. We show through various experiments that our proposed algorithm outperforms the existing algorithm In terms of throughput and response time.

• Journal of Digital Convergence
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• v.16 no.2
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• pp.19-26
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• 2018

We proposed a numerical calculation of the proportion of necrotic cells in pulmonary segmentation, pulmonary vessel segmentation lung disease site for diagnosis of lung disease from chest CT images. The first step is to separate the lungs and bronchi by applying a three-dimensional labeling technique from a chest CT image and a three-dimensional region growing method. The second step is to divide the pulmonary vessels by applying the rate of change using the first order polynomial regression, perform noise reduction, and divide the final pulmonary vessels. The third step is to find a disease prediction factor in a two-step image and calculate the proportion of necrotic cells.