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간 자기공명영상검사에서 VIBE 시퀀스의 고식적인 방법과딥러닝의 비교 및 유용성 평가
이충성,백인성,김경환,강보걸 대한자기공명기술학회 2023 대한자기공명기술학회지 Vol.33 No.3
Liver DCE imaging uses the VIBE sequence, but previous research into conventional and deep-learning methods using AI is lacking. We therefore used image evaluation and examination direction and validity . The ACR phantom study was repeated 30 times. In the low contrast resolution evaluation area, SNR and CNR were evaluated using Syngovia View&Go. In the spatial resolution evaluation area, the height of signal intensity and FWHM were evaluated through MATLAB. For the patient study, Matrix 352 was set up based on the phantom study and tested on 30 patients. SNR and CNR were evaluated at the liver parenchyma, hepatic portal vein, and descending aorta. Spatial resolution was evaluated at the borders of the hepatic portal vein and descending aorta. The data were analyzed using a two-way ANOVA and a post-hoc analysis was performed using the Duncan test. The results revealed significant differences in the SNR and CNR of the phantom study under Matrix 416, while spatial resolution could not be evaluated under the conventional method Matrix 352 or the deep-learning method Matrix 288. The results of the patient study showed significant differences in SNR, CNR, and spatial resolution. The deep learning method improved the image more than the classical method, and the acquisition time was reduced by an average of 4 seconds (22.4%). When Matrix 352 was applied in the deep learning method, there was a decrease in reproducibility and respiration artifacts due to a reduction in scan time. Accordingly, we recommend applying Matrix size in the deep learning method.
이충성,지남철 조선대학교 1994 The Medical Journal of Chosun University Vol.19 No.2
Cyclic Strabismus is a relatively rare disorder of ocular motility that is reported to occur in one in 3000 to 5000 cases of strabismus. It is characterized by the fact that ocular deviation is present on a rhythmic basis. The type of deviation is classically a large-angle exotropia alternating with orthophoria or a small-angle esodeviation on a 48-hour cycle. In the present study, one case of cyclic esotropia in a 4-year-old male who represents periodic ocular deviation on a alternate daily was discussed. The periodic esodeviation was treated with bimedial rectus recession.
나카가미 페이딩 채널에서 선택 합성 다이버시티를 적용한 FH/MFSK 시스템의 성능분석
이충성,김항래,김남,Lee, Chung-Seong,Kim, Hang-Rae,Kim, Nam 한국전자파학회 2000 한국전자파학회논문지 Vol.11 No.7
본 논문에서는 나카가미 패이딩 채널에서 FH/MFSK 시스템에 선택 다이버시티를 적용하였을 경우의 시스템 성능을 분석한다. 선택 합성(selection combining)후의 신호대 잡음비(SNR)로부터 제거확률을 유도하고 FH/MFSK 시스템의 성분분석을 위해 사용자수(M), SNR, 나카가미 페이딩(m), 다이버시티 가지의 수(D)와 같은 파라메더들을 사용한다. m이 1인 경우, 비트에러율(BER)은 각각 D=1에서 1.0$\times$10-3이고 D=2에서 1.0$\times$10-4으로 10배만큼 감소함을 알 수 있다. m이 2인 경우, BER은 D가 증가하더라도 일정한 값을 갖는다는 것을 또한 알 수 있다. D가 2인 경우, SNR이 15dB와 25dB일 때의 시스템 용량은 다이버시티를 고려하지 않은 용량보다 각각 75%와 20% 증가된다. In this paper, the system performance with the selection diversity, which is applied to the FH/MFSK system in Nakagami fading channel, is analyzed. The deletion probability is derived from the received signal to noise ratio(SNR) after selection combining and the parameters such as the number of users(M), SNR, Nakagami fading figure(m), and the number of diversity branches(D) is used for the performance analysis of the FH/MFSK system. Assuming that m set 1, it is observed that the bit error rate(BER) is 1.0$\times$$10^{-3}$ and 1.0$\times$$10^{-4}$ at D =1(no diversity) and D=2, respectively, and then is decreased by 10 times. Assuming that m set 2, it is also shown that the BER has a constant value although D is increased. In the case of D=2, the system capacity is more 75% and 20% than that considering no diversity at SNR=15 dB and 25 dB, respectively.
이충성,유재영,여규동,이상원 국토연구원 2010 국토연구 Vol.64 No.-
Since the river usually flows over several regions, there may have the cost allocation issues for constructing flood protection measures in flood mitigation management. The purpose of this study is to suggest an alternative for the solution of a cost allocation issue that usually occurs at planning projects for flood mitigation management. As a case study, we selected the cost allocation issue in constructing flood protection measures in Najinpo and Gyeoyang rivers, which are tributaries of Han river and flow through Incheon in upstream and Gimpo in downstream, and suggested the inter-regional cost allocation method from the case study. The theoretical approach for the cost allocation was based on the cooperative game theory, and in terms of methodology, we used the SCRB (Separable Cost Remaining Benefit) and Shapley value method which are comparatively easy to apply. From the study, the cost allocation ratio between upstream and downstream regions are approximately 54% vs. 46% in Najinpo river basin and 70% vs. 30% in Gyeoyang river basin respectively. This study is expected to provide an alternative for solving the similar cost allocation problems for flood mitigation management which may be occurred frequently in the future between two or more regions, especially upstream and downstream. 일반적으로 하천은 여러 지역에 걸쳐 흐르기 때문에 하천 치수관리를 위한 홍수방어시설물들을 건설할 때에 대해 발생하는 비용에 대하여 상·하류 지역 간 비용배분의 문제가 발생하게 된다. 본 연구의 목적은 유역 내 치수관리를 위한 사업계획 시 발생하는 비용배분 문제해결의 대안을 제시하는 것이다. 이를 위한 사례연구로서 본 연구는 한강 지류인 나진포천 및 계양천의 홍수방어시설 건설에 따른 비용배분 문제를 선정하였고, 상류인 인천시와 하류인 김포시 간의 지역 간 비용배분 방안을 제시하였다. 비용배분의 해법을 위한 이론적 전개는 협조적 게임이론을 바탕으로 하였고, 방법론 측면에서는 비교적 적용이 간편한 분리비용잔여편익법 및 샤플리법을 사용하였다. 분석결과, 상류와 하류 간의 비용배분 비율은 나진포천 유역에서 약 54% : 46%, 계양천 유역에서 약 70% : 30%로 각각 나타났다. 본 연구는 둘 이상의 지역 간, 특히 상류와 하류 간에 향후 빈번하게 발생될 것으로 보이는 유사한 하천 치수관리 비용배분 문제의 해결을 위한 대안을 제시할 것으로 기대된다.
도시지역과 전원지역의 홍수피해 비교를 통한홍수피해산정방법의 적정성 평가
이충성,심명필,최승안,장준경 국토연구원 2006 국토연구 Vol.48 No.-
Adequacy Evaluation of Flood Damage Assessment Models by Comparing Flood Damages between Urban and Rural Area