• Journal of the Institute of Convergence Signal Processing
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• v.15 no.2
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• pp.24-29
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• 2014

Digital mammography is the most common technique for the early detection of breast cancer. To diagnose the breast cancer in early stages and treat efficiently, many image enhancement methods have been developed. This paper presents a multi-scale contrast enhancement method in the Laplacian pyramid for the digital mammogram. The proposed method decomposes the image into the contrast measures by the Gaussian and Laplacian pyramid, and the pyramid coefficients of decomposed multi-resolution image are defined as the frequency limited local contrast measures by the ratio of high frequency components and low frequency components. The decomposed pyramid coefficients are modified by the contrast measure for enhancing the contrast, and the final enhanced image is obtained by the composition process of the pyramid using the modified coefficients. The proposed method is compared with other existing methods, and demonstrated to have quantitatively good performance in the contrast measure algorithm.

• Korea journal of population studies
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• v.34 no.2
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• pp.163-190
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• 2011

This study assessed the manner in which social activities, religious experiences, and spiritual practices related to depression and life satisfaction among 217 Korean elderly individuals, aged 65 to 80. The Social Activities Scale and Brief Multidimensional Measure of Religiosity/Spirituality were employed to assess social activities and six domains of religiosity/spirituality: daily spiritual experiences, values, forgiveness, private religious practice, religious/spiritual coping, and religious support. In addition, depression was assessed with the Geriatric Depression Scale, and life satisfaction with the Satisfaction with Life Scale. After controlling for demographic variables, lower depression scores were predicted by higher levels of religious and spiritual coping, social activities, higher income, and ower daily spiritual experiences. In addition, identifying as female, advanced old age, and lower social activities predicted lower life satisfaction in this study. The implications of this study's findings on social work practice are also discussed, along with some future research directions.

• Journal of Navigation and Port Research
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• v.34 no.5
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• pp.389-395
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• 2010

Recently, it becomes important for container ports to gain competitiveness through service differentiation strategies. These strategies require an objective evaluation on consumer needs. For that reason, this study aims at developing the scale and measurement methods for service quality. Container shipping companies calling at Busan are targeted for the empirical analyses. The measurement items are presented for the services that they are provided from entry into a port to departure from a port. Exploratory factor analysis and validity analysis are done to derive a service quality scale from entry to departure. The result of regression analysis implies that the service quality scale is useful to increase customer satisfaction and to establish managerial strategies.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.04a
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• pp.149-156
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• 2002

본 연구에서는 항공사진 및 지상사진 등 다양한 형태의 영상자료를 이용하여 도로시설물 정보를 추출하고자 하였다. 지상취득 영상으로는 현재 많이 쓰이고 있으며 비교적 저가품인 일반카메라, 디지털카메라, 비디오카메라에 의하여 촬영된 단사진 영상을 이용하였고, 여기서 추출한 공간자료와 속성자료는 자료기반의 수정과 갱신에 사용하였다. 아울러 단사진 영상으로부터 추출한 공간자료를 이용하여 상대적인 척도로서 수치지도의 생성 가능성을 타진하였다.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.865-868
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• 2001

TCM offers considerable coding gains without compromising bandwidth or signal power. But TCM decoder is more complex than convolutional Viterbi decoder. Because, the number of branches exponentially increased by the constraint length and input symbol bits. The parallelism of ACS and memory management technique of SPMM is one of the important factor for speed-up and hardware complexity. This paper proposes a multi-processing technique of ACS and also gives a memory management technique of SPMM in TCM decoders.

• ETRI Journal
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• v.14 no.1
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• pp.118-125
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• 1992

다중 컴퓨터 연결망의 성능은 그 위상에 따라 크게 좌우되는데 현재까지 연구된 많은 연결망중에서 특히 하이퍼큐브 연결망은 노드수에 비해 비교적 적은 차수와 지름을 갖고 symmetric 하며 순환적 구성 (recursive decomposition structure) 특성을 갖고 있어 여러가지 알고리즘의 사상이 용이하여 많이 사용되고 있다. 여기서는 $Akers^2$ 등에 의해 제안되어 스타 그래프 (star graph) 에 대해 성능분석을 하였다. 분석 척도로는 노드간 평균거리를 사용하였으며 메시지 분포는 $Reed^(1)$가 사용한 분포를 사용하였다. 분석결과 스타 그래프 연결망은 하이퍼큐브와 비슷한 성능을 보였으며 노드 수가 많아질수록 더 나은 성능을 보였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.04a
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• pp.134-147
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• 1994

고차근사가 혼돈응답에 미치는 영향을 조사하기 위하여 비선형문제의 전형인 탄성진자계를 집중적으로 조사하였다. 조화가진력을 가진 탄성진자계는 비자율계(원래계)로 나타나는데 다중시간법을 사용하여 이 계를 이차근사에 의한 자율계 (근사화계)로 변환하였다. 점근해의 초기조건에 대한 민감도의 척도인 Lyapunov 지수를 통하여 비교해 본 결과, 이차근사에 의한 근사화계가 일차근사에 의한 근사화계보다 원래계를 더 잘 반영하고 있음을 확인하였다. 이로써 고차근사가 정상상태 주기응답 뿐만 아니라 혼돈응답을 더 정확하게 예측하는 데도 유용함을 알 수 있었다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.286-287
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• 2008

This paper proposes a power system blackout model and devises a method of identification and selection of higher-order contingencies that may threaten power system security. To study how failures spread in power grids, network observability based on topological concept is utilized which provide a means of monitoring network evolutions due to multiple contingencies. The simulations and results are presented using the IEEE 118-bus test system.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.390-392
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• 1999

본 논문은 ATM 망에서 다중 멀티캐스팅 서버를 이용한 IP 멀티캐스팅 방안의 성능을 평가할 수 있는 망 시뮬레이터를 구현하였다. 본 연구에서 구현한 망 시뮬레이터는 다양한 네트워크 모델 및 멀티캐스트 트리 구축 방안을 적용할 수 있도록 객체 지향 설계 원리에 따라 설계되었다. 구현한 망 시뮬레이터는 랜덤 네트워크 생성, 다중 멀티캐스팅 서버 생성 및 분포, 다양한 멀티캐스트 트리 구축 방안 지정 및 성능 결과 생성 기능을 포함한다. 이것은 보다 복잡한 성능 평가 척도를 포함하여 보다 실제적인 멀티캐스팅 방안의 성능 평가도구로 확장 될 수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2A
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• pp.187-194
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• 2004

We propose priority-based reservation code multiple access (P-RCMA) which can enhance voice traffic quality of the previous RCMA. The proposed protocol maintains two power levels and consider traffic characteristics in contending shared available codes to transmit packets. P-RCMA gives priority to the voice request packets rather than data packets by capture effect at the receiver part of base station. We show numerical results from EPA (equilibrium point analysis) analysis and simulation study in terms of voice packet dropping probability and average data packet transmission delay.