• Journal of radiological science and technology
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• v.31 no.1
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• pp.25-31
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• 2008

Purpose : This study was conducted to understand for the diagnostic discordance of bone mineral density(BMD) in DEXA(Dual Energy X-ray Absorptiometry). And the diagnostic difference between lumbar spine and femur neck, forearm was evaluated using T-score. Materials and Methods : We studied 220 females measured BMD on lumbar spine, and femur neck, forearm including ward's triangle and ultra digital(UD). We were distinguished T-score into normal, osteopenia, osteoporosis(WHO classification) and evaluated discordance rate according to age and degree of bone loss. Correlation analysis and chi-square test between L-spine, L-4, femur neck, Ward, Forearm, UD were carried out. Results : In the lumbar spine, the number of normal were in 57(25.9%), osteopenia in 86(39.1%), osteoporosis in 77(35.0%). In the L-4 and ward's triangle, the number of osteoporosis were in 78(35.5%), in 126(57.3%). There was significant correlation between lumbar, femur neck and forearm BMD in all cases. The discordance of BMD between lumbar and femur were 57%, lumbar and forearm 43%, forearm and femur 51%. The discordance rates of normal, osteopenic, osteoporotic groups were 39%, 64%, 43%, respectively, showing the highest discordance rate in osteopenia patients. In normal group of lumbar spine, the discordance rate was 25%, 23%, 11%, 65%, 86% in 30', 40', 50', 60', 70', respectively. In osteopenia, osteoporosis group of lumbar spine, the discordance rate was 62%, 55%, 36%, 20%, 9% in 30', 40', 50', 60', 70', respectively. Conclusion : It was different of the results of BMD with lumbar, femur and forearm site. The discordance rate was decreased with age in osteopenia, osteoporosis lumbar spine. In osteopenia group, the discordance rate was the highest. So, it is necessary that the BMD of lumbar, femur neck and forearm should be checked.

• Journal of the Korean Society of Radiology
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• v.82 no.6
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• pp.1545-1555
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• 2021

Purpose The purpose of this study was to evaluate the rates of unacceptable diagnosis and clinically significant diagnostic discrepancy in radiology sections and imaging modalities through a peer review of teleradiology. Materials and Methods Teleradiology peer reviews in a Korean teleradiology clinic in 2018 and 2019 were included. The peer review scores were classified as acceptable and unacceptable diagnoses and clinically insignificant and significant diagnostic discrepancy. The diagnostic discrepancy rates and clinical significance were compared among radiology sections and imaging modalities using the chi-square test. Results Of 1312 peer reviews, 117 (8.9%) cases had unacceptable diagnoses. Of 462 diagnostic discrepancies, the clinically significant discrepancy was observed in 104 (21.6%) cases. In radiology sections, the unacceptable diagnosis was highest in the musculoskeletal section (21.4%) (p < 0.05), followed by the abdominal section (7.3%) and neuro section (1.3%) (p < 0.05). The proportion of significant discrepancy was higher in the chest section (32.7%) than in the musculoskeletal (19.5%) and abdominal sections (17.1%) (p < 0.05). Regarding modalities, the number of unacceptable diagnoses was higher with MRI (16.2%) than plain radiology (7.8%) (p < 0.05). There was no significant difference in significant discrepancy. Conclusion Peer review provides the rates of unacceptable diagnosis and clinically significant discrepancy in teleradiology. These rates also differ with subspecialty and modality.

• The Journal of the Korea Contents Association
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• v.17 no.1
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• pp.113-119
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• 2017

This study aims at investigating which factors affect the public perceptions of the survival rate of cancer. To this end, this study compares the public perception for 5-year survival rates of five major cancer(stomach, colorectal, liver, breast, uterine cervix) and actual epidemiological fact thereof. Data was collected from 19th to 24th April 2016 through online cross-sectional survey on 354 people. Frequency analysis was conducted to understand the characteristics of the subjects, histograms were presented for the comparison with the epidemiological fact, and multiple regression analysis was conducted. The subjects tended to aware the survival rates of stomach cancer, colorectal cancer, breast cancer, and uterine cervix cancer as lower than they epidemiologically represented. Finally, the factors that substantially affect the perception of 5-year survival rates were revealed as the experience of diagnosed as cancer, the age, and whether the subject regularly involved in a workout.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.2A
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• pp.99-108
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• 2002

In this paper, we discuss the effect of imperfect knowledge of the transmission channel on the M-QAM SER performance of space-time block codes. Because the channel knowledge is used for decoding of space-time block codes, the imperfect channel knowledge can degrade the performance of space-time block codes. In this paper, the channel mismatch error is modeled as errors in the estimation of the channel due to noise and errors due to the variation of the channel. We derive the analytic expression for the symbol error rate (SER) as a function of the average signal to interference ratio (SIR) per channel including the terms of channel mismatch errors. Simulation results show that the acceptable levels of channel estimation error is 10$\^$-3/ and that of channel variation is f$\_$d/T$\_$B/=0.001 at SNR=20dB in space-time block codes.

• Journal of Food Hygiene and Safety
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• v.38 no.6
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• pp.464-475
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• 2023

In this study, based on an analysis of two DNA barcode markers (cytochrome c oxidase subunit I and cytochrome b genes), we performed species identification and monitored labeling compliance for 50 commercial pufferfish products sold in on-line markets in Korea. Using these barcode sequences as a query for species identification and phylogenetic analysis, we screened the GenBank database. A total of seven pufferfish species (Takifugu chinensis, T. pseudommus, T. xanthopterus, T. alboplumbeus, T. porphyreus, T. vermicularis, and Lagocephalus cheesemanii) were identified and we detected 35 products (70%) that were non-compliant with the corresponding label information. Moreover, the labels on 12 commercial products contained only the general common name (i.e., pufferfish), although not the scientific or Korean names for the 21 edible pufferfish species. Furthermore, the proportion of mislabeled highly processed products (n = 9, 81.8%) was higher than that of simply processed products (n = 26, 66.7%). With respect to the country of origin, the percentage of mislabeled Chinese products (n = 8, 80%) was higher than that of Korean products (n = 26, 66.7%). In addition, the market and dialect names of different pufferfish species were labeled only as Jolbok or Milbok, whereas two non-edible pufferfish species (T. vermicularis and T. pseudommus) were used in six commercial pufferfish products described as JolboK and Gumbok on their labels, which could be attributable to the complex classification system used for pufferfish. These monitoring results highlight the necessity to develop genetic methods that can be used to identify the 21 edible pufferfish species, as well as the need for regulatory monitoring of commercial pufferfish products.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.05a
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• pp.169-172
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• 2003

본 논문에서는 기존의 분절 단위 비교방법에서 참조서명과 비교서명간에 분할점 개수와 위치에 대한 불일치 문제를 개선하기 위해 구간 분할 매칭 방법을 제안한다. 제안된 분할방법은 시간에 대한 x와 y좌표 상에서 서명마다 변하지 않는 특징점을 구간 분할점으로 선택하여 구간별로 매칭시킴으로서 분절의 안정적인 분할을 통해 인식률을 높이고자 한다. 실험 결과에서 진서명과 위조서명을 포함한 기타서명에 대해 FAR이 0.06%일 때 FRR 1.25%의 오류율을 확인하였으며 FAR이 0%일 때의 평균인식율이 98.7%를 보임으로써 제안한 서명 검증 기법이 우수함을 확인 할 수 있었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11c
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• pp.1617-1620
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• 2003

본 논문은 사용자 질의가 가지는 특정 클래스로부터 개념적으로 서로 연관있는 컴포넌트를 검색하기 위하여 퍼지 시소러스를 통한 질의 평가 방법을 이용하였다. 시소러스에 의한 사용자 질의 확장과정은 용어 불일치 문제를 해결함으로써 검색에 대한 일정한 정확도를 보장하면서 재현율을 향상시킬 수 있게 한다. 필의 확장과정의 효율성을 평가하기 위하여 시뮬레이션을 통한 최적의 검색 효율을 나타내는 임계치를 설정하고 재현율과 정확도를 비교하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.77-79
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• 2010

본 논문은 다시점 비디오의 조명 불일치 현상을 효과적으로 보상하기 위한 히스토그램 매칭 기법의 성능을 향상시키는 영상의 에지 방향성을 고려한 전처리 기법을 제안하였다. 다시점 비디오는 카메라 간 서로 다른 위치와 방위로 인해 인접한 시점 영상 간에 존재하는 동일 물체에 색상 차이가 발생할 수 있다. 히스토그램 매칭 기법은 모든 시점 영상의 히스토그램을 정해진 참조시점 영상의 히스토그램에 매칭시켜 다시점 비디오의 조명 불일치 현상을 보상하는 방법이다. 본 논문에서는 히스토그램 매칭을 수행하기 전에 ELA(Edge-based Line Averaging) 선형 보간 기법과 Cosited 대표 값 추출 필터를 결합한 전처리 필터를 선행하여 조명 보상 효과와 다시점 부호화 성능을 향상시켰다. 실험을 통해 제안하는 전처리 기법이 일반적인 다시점 비디오 부호화에 비해 약 2 dB의 평균 PSNR 향상과 34%의 비트율 절감 효과를 가짐을 확인하였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.01a
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• pp.155-156
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• 2016

한국의 대학은 높은 교육열, 자녀 수 감소, 일자리 창출 미흡, 전공.직업 불일치율 50%(OECD 2015 보고서)등 교육 수요자의 기대와 기업이 선호하는 인재양성을 해야 하는 대학교육의 위기이다. 이 위기에 IoT, 클라우드(Cloud), 빅데이터(Big data), 모바일(Mobile) 기술을 원활하게 지원하기 위한 소프트웨어(SW)가 필수적이다. 'SW 경쟁력 없이는 기업의 미래가 없다', 'SW 인재가 세상을 바꾼다'등 SW의 중요성과 비전이다. 미국의 구글, 애플, 페이스북, 트위터와 중국의 바이두, 알리바바, 텐센트 등도 SW를 바탕으로 전 세계로 뻗어가고 있다. 지금이 SW 강국으로 가는 마지막 기회로, SW 중심사회 실현을 위한 인재양성 확대가 시급하다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.157-171
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• 2021

As smartphones spread and ICT technologies develop, taxi services have changed from hovering to platform-based calls and reservations. This has improved the mobility and accessibility of taxi users but caused problems, such as digital observing (no-responses to calls) for either short-distance services or services during the peak-demand periods. Digital Observing means ignoring and not accepting calls when they occur, which require improvement. Therefore, this study aims to derive measures to mitigate discrepancies in taxi supply and demand by adjusting the expected revenue of each taxi service using reinforcement learning based on the Taxi operation data. The results confirmed that the average complete response rate to calls would increase from 50.29% to 54.24% when incentives are applied, and an improvement of 5.86% can be achieved in short-distance sections of less than 5,000 won incentives. It is expected that the improvement will increase profitability for drivers, reduce the waiting time for passengers, and improve satisfaction with taxi services overall.