경부종괴의 초음파소견에 관한 고찰

차상훈,서원혁 최신의학사 1986 最新醫學 Vol.29 No.11

4차 산업혁명과 스마트공항 추진방안

차상훈 한국항공경영학회 2017 한국항공경영학회 추계학술대회 Vol.2017 No.-

Efficient Implementation of Single Error Correction and Double Error Detection Code with Check Bit Pre-computation for Memories

차상훈,윤홍일 대한전자공학회 2012 Journal of semiconductor technology and science Vol.12 No.4

In this paper, efficient implementation of error correction code (ECC) processing circuits based on single error correction and double error detection (SEC-DED) code with check bit pre-computation is proposed for memories. During the write operation of memory, check bit pre-computation eliminates the overall bits computation required to detect a double error, thereby reducing the complexity of the ECC processing circuits. In order to implement the ECC processing circuits using the check bit precomputation more efficiently, the proper SEC-DED codes are proposed. The H-matrix of the proposed SEC-DED code is the same as that of the odd-weightcolumn code during the write operation and is designed by replacing 0’s with 1’s at the last row of the H-matrix of the odd-weight-column code during the read operation. When compared with a conventional implementation utilizing the oddweight-column code, the implementation based on the proposed SEC-DED code with check bit precomputation achieves reductions in the number of gates, latency, and power consumption of the ECC processing circuits by up to 9.3%, 18.4%, and 14.1%for 64 data bits in a word.

서울지역에서의 강수패턴 분류모형

차상훈,이경은,김광섭 한국데이터정보과학회 2019 한국데이터정보과학회지 Vol.30 No.5

This study identified seasonal rainfall patterns in Seoul by using hourly precipitation of raining data, and we used hourly precipitation on the day before, average daily precipitaion, temperature, wind speed, humidity, and dew point to classify these patterns. Using k-medoids clustering, the seasonal precipitaion patterns were identified for the constructed data. As a result, there were 6 precipitation patterns in spring and summer, 5 precipitation patterns in autumn and 4 precipitation patterns in winter. To classify these patterns, we constructed a model to classify seasonal precipitation patterns into 4 methods : Linear Discriminant Analysis, Decision Tree, Bagging, and Random Forest, and verified by 5-fold cross-validation. As a result, in spring, summer, and autumn, the precipitation pattern classification rate was highest when applied by Random Forest, whereas in winter, the classification rate was highest when applied by Decision Tree. 본 연구는 강수 발생한 자료의 1시간당 강수량을 이용하여 서울지역의 계절별 강수패턴들을 파악하고, 이 패턴들을 분류하기 위하여 하루 전날의 1시간당 강수량, 1일 평균 강수량, 기온, 습도, 풍속, 이슬점온도를 활용하였다. 구축된 자료에 대하여 k-medoids 군집분석을 통해 봄과 여름에는 6가지, 가을에는 5가지, 그리고 겨울에는 4가지의 강수패턴들이 보였다. 이 패턴들을 분류하기 위해 4가지 방법인 선형 판별 분석, 의사결정나무, 배깅, 그리고 랜덤 포레스트로 계절별 강수 패턴들을 분류하는 모형을 구축하고 5-fold 교차검증으로 검증하였다. 그 결과 봄, 여름, 가을의 경우, 랜덤 포레스트의 방법으로 적용하였을 때 강수 패턴 정분류율이 가장 높은 반면, 겨울의 경우, 의사결정나무의 방법으로 적용했을 때 정분류율이 가장 높았다.

A Study on The Performance of A Water Heat Pump System

차상훈,고성호 한국유체기계학회 2019 한국유체기계학회 논문집 Vol.22 No.3

The main purpose of this study is to derive the optimal operating conditions and determine control variables for a water source heat pump system. In this study, a water heat pump system from the K-water S water treatment plant was used as the pilot system. An inverter system was applied to the raw water, brine water, and circulation water pump to conduct an optimal operating condition analysis. In addition, a real-time monitoring and control system was implemented to calculate the system efficiency. The real-time monitoring system stores the flow, temperature, pressure, power, and pump operation data every 10 minutes. A simulation model was developed to analyze the system COP under various operating conditions and the model was calibrated using a pump performance test. The variation of the system efficiency was simulated by varying the flow rate of the pumps with respect to the raw water temperature. The simulation analysis and operation data were compared and the effectiveness of introducing a variable speed water heat pump system was verified. Finally, the control variables related to the systems efficiency were derived.

수학적 모델과 폭발사고 모델링을 통한 산화에틸렌 공정의 설비 배치 최적화에 관한 연구

차상훈,이창준 한국안전학회 2020 한국안전학회지 Vol.35 No.1

In most plant layout optimization researches, MILP(Mixed Integer Linear Programming) problems, in which the objective function includes the costs of pipelines connecting process equipment and cost associated with safety issues, have been employed. Based on these MILP problems, various optimization solvers have been applied to investigate the optimal solutions. To consider safety issues on the objective function of MILP problems together, the accurate information about the impact and the frequency of potential accidents in a plant should be required to evaluate the safety issues. However, it is really impossible to obtain accurate information about potential accidents and this limitation may reduce the reliability of a plant layout problem. Moreover, in real industries such as plant engineering companies, the plant layout is previously fixed and the considerations of various safety instruments and systems have been performed to guarantee the plant safety. To reflect these situations, the two step optimization problems have been designed in this study. The first MILP model aims to minimize the costs of pipelines and the land size as complying sufficient spaces for the maintenance and safety. After the plant layout is determined by the first MILP model, the optimal locations of blast walls have been investigated to maximize the mitigation impacts of blast walls. The particle swarm optimization technique, which is one of the representative sampling approaches, is employed throughout the consideration of the characteristics of MILP models in this study. The ethylene oxide plant is tested to verify the efficacy of the proposed model.

초음파를 이용한 표재성 신경초종의 분석 : 초음파기기 주파수 및 종양의 변성이 후방음파증강에 미치는 영향 The Influence of Sonographic Frequency and the Degenerative Change of Tumor on the Posterior Acoustic Enhancement

차상훈,설혜영,정규병 고려대학교 의과대학 1994 고려대 의대 잡지 Vol.31 No.2

We retrospectively analyzed the sonographic findings of 18 pathologically proven superficial neurilemmomas in 17 patients during recent 5 years. We evaluated the contuor, size and internal echo pattern of the tumor, the presence of tumor capsule, and the degree of acoustic enhancement behind the tumor. We correlated the posterior acoustic enhancement with the pathologic features. Eighteen tumors showed oval or round in contuor and 9 tumors revealed hypoechoic pattern, 3 tumors revealed homogenously echogenic pattern and 6 tumors revealed heterogenously echogenic pattern. Sixteen tumors showed the capsule of tumor. Fourteen tumors showed posterior acoustic enhancement. Grade Ⅰ posterior acoustic enhancements were noted at 10 MHz transducer examination only and Grade Ⅱ posterior acoustic enhancements were noted at 5 MHz or 7.5 MHz tranducer examination. No definite correlation between hemorrhagic or cystic degenerations of superficial neurilemmomas and Grade Ⅱ posterior acoustic enhancements were noted. The mean size of hypoechoic superficial neurilemmoma was smallest and that of heterogenously echogenic superficial neurilemmoma was largest. We conclude that sonographic exammination was useful for evaluation of superficial neurilemmoma.

Isolation and Characterization of Human scFv Molecules Specific for Recombinant Human Heat Shock Protein (HSP) 70.1

차상훈,이재선,서정선,백현정 대한면역학회 2004 Immune Network Vol.4 No.1

Background: The heat shock proteins (HSPs) play an important role in cellular protection mechanisms against physical or chemical stresses. In this study scFv antibodies specific for human HSP70.1 were isolated from a semi-synthetic human scFv library with the ultimate goal of developing anti-HSP70.1 intracellular antibody (intrabody) that may offer an attractive alternative to gene targeting to study the function of the protein in cells. Methods: A semi-synthetic human scFv display library (5 108 size) was constructed using pCANTAB-5E vector and the selection of the library against bacterially expressed recombinant human HSP70.1 was attempted by panning. Results: Three positive clones specific for recombinant HSP70.1 were identified. All three clones used VH subgroup III. On the other hand, VL of two clones belonged to the kappa light chain subgroup I, but the other utilized Vk subgroup IV Interestingly, these scFv molecules specifically reacted to the recombinant HSP70.1, yet failed to recognize native HSP70 induced in U937 human monocytic cells by heat treatment. Conclusion: Our results indicated that affinity selection of an scFv phage display library using recombinant antigens produced in E. coli might not guarantee the isolation of scFv antibody molecules specific for a native form of the antigen. Therefore, the source of target antigens needs to be chosen carefully in order to isolate biofunctional antibody molecules. (Immune Network 2004;4(1):7-15)

단일크론성 항체를 이용한 융모막 성선자극 호르몬의 효소 면역측정법

차상훈,김희주,김원배,양중익 대한약학회 1987 약학회지 Vol.31 No.2

Monoclonal antibodies against human chorionic gonadotropin (hCG) were prepared and characterized by examining isotype, epitope binding, cross reactivity and affinity constants. And a sandwich type enzyme immunoassay for native hCG was developed with solid phase monoclonal antibody against the conformational determinant expressed only on native hCG and horseradish peroxidase conjugated monoclonal antibody against the $\beta$-subunit of hCG. The assay was sensitive to 1 mIU hCG/ml and shown a linear response up to 200 mIU hCG/ml. The cross reactivity for luteinizing hormone and $\beta$-subunit of hCG were 1% and 0.18%, respectively.

EC 保護貿易主義와 그 對應方案에 관한 硏究

차상훈 경기대학교연구교류처 1984 論文集 Vol.15 No.1