뇌 동맥류 질환 자기공명검사에서 고분해능(High-Resolution) 기법의 관한 연구 - 고분해능기법과 표준기법 비교 -

최성현,구은회,황선광,이강원,이종웅,Choi, Sung-Hyun,Goo, Eun-Hoe,Hwang, Sun-Kwang,Lee, Gang-Won,Lee, Jong-Woong 대한디지털의료영상학회 2012 대한디지털의료영상학회논문지 Vol.14 No.1

The purpose of this study was to examine usefulness of 3T equipment-based time-of-flight magnetic resonance angiography (3T-TOF MRA) by comparing standard technique (ST) with high resolution technique (HRT) in evaluation of cerebral blood vessel. The 3T-TOF MRA was performed for 31 patients who were suspected of having cerebrovascular disease from March to July 2010. For evaluation of cerebral blood vessel, classification was conducted randomly: group I that included vertebral artery and basilar artery, group II that ranged from 2.5cm before basin part of common carotid artery to basin part of internal and external carotid arteries and to genu part of internal carotid artery, group III that ranged from vertebral part of internal carotid artery to the first basin art of anterior and middle cerebral through education recognizes the importance of dose reduction and examine if their efforts and further reduce patient dose could achieve optimization of the medical exposure is considered.

CD Copy업무 flow개선을 통한 고객만족도 향상에 관한 연구 - QI 활용을 중심으로 -

최성현,황선광,이종웅,동경래,권대철,구은회,박창희,Choi, Sung-Hyun,Hwang, Sun-Kwang,Lee, Jong-Woong,Dong, Kyung-Rae,Kweon, Dae-Cheol,Goo, Eun-Hoe,Park, Chang-Hee 대한디지털의료영상학회 2011 대한디지털의료영상학회논문지 Vol.13 No.3

This is to improve the complicate process of the existing CD copy flow in Department of Radiology. It is also to improve the medical service of the hospital to secure private information of patients. Survey: The patients who ask for CD copies in the Department of Radiology of this hospital(for 6 months in 2010). Time: Comparing the total amount of time of the previous and the modified CD copy flow. Using the SPSS 12.0 program for testing significance of independent two-samples t-test. Private information: Introducing the identification-system based on the medical law to supplement the security of personal information of patients. There was manifold complaints due to receipt and issuing the prescription in Admission and Discharging office and outpatient department. The time has been approximately 50% reduced from 70 mistunes to 32 mistunes due to simplifying the routes. The security of the personal information has been supplemented by let patients submit documentary evidence based on the medical law. The service in the hospital has been improved as a result of simplifying the whole process of the routes and receipt process. Therefore, the each stage of waiting time has been decreased. In addition, the personal information of the patients has been more secured.

건물 규모 및 재현주기 변화에 따른 주거용 RC건물에 대한 시공 중 지진하중의 영향 분석

최성현,김재요,Seong-Hyeon Choi,Jae-Yo Kim 한국전산구조공학회 2023 전산구조공학 Vol.36 No.2

Unlike a completed building, a building under construction may be at risk in terms of safety if a load exceeds the value considered in the design stage owing to various factors, such as a load action different from that in the design stage and insufficient concrete strength. In addition, if an earthquake occurs in a building under construction, greater damage may occur. Therefore, this study studied example models with various sizes of 5, 15, 25, and 60 floors for typical building types and analyzed the effects of seismic load on buildings under construction using construction-stage models according to frame completeness. Because the construction period of the building is much shorter than the period of use after completion, applying same earthquake loads as the design stage to buildings under construction may be excessive. Therefore, earthquakes with a return period of 50 to 2,400 years were applied to the construction stage model to review the seismic loads and analyze the structural performances of the members. Thus, we reviewed whether a load exceeding that of the design stage was applied and the return period level of the earthquake that could ensure structural safety. In addition, assuming the construction period of each example model, the earthquake return period according to the construction period was selected, and the design appropriateness with the selected return period was checked.

구기자술의 저장에 따른 성분변화

최성현,이미현,신철승,성창근,오만진,김찬조,Choi, Seong-Hyun,Lee, Mi-Hyun,Shin, Cheol-Seung,Sung, Chang-Keun,Oh, Man-Jin,Kim, Chan-Jo 한국응용생명화학회 1996 Applied Biological Chemistry (Appl Biol Chem) Vol.44 No.3

한방에서 강장과 보간 등에 효과가 있는 것으로 알려진 구기자를 원료로 술을 양조하여 그 일반성분, 유기산, 메탄올, ester, 휴젤유 및 $SO_2$ 등을 조사하였고, $20^{\circ}C$와$30^{\circ}C$에서 20일 저장하면서 위의 성분분석과 관능 검사를 하였다. 보당형 구기자술 중의 유기산량은 젖산, 능금산, 주석산 및 초산 등이 주를 이루었으며 ester 및 휴젤유는 각각 $4.0{\sim}5.0\;mg%$와 $12{\sim}30\;mg%$ 그리고 methanol은 $25{\sim}27\;mg%$이었다. 약주형 구기자술의 ester 및 휴젤유는 보당형보다 많았다. 한편, 보당형 및 약주형 구기자술의 주질에 미치는 저장온도는 $30^{\circ}C$보다 $20^{\circ}C$가 좋았으며 살균 처리법은 $SO_2$ 100 ppm 첨가 또는 $60^{\circ}C/30$분의 처리가 좋았다. Fruit of Lycium chinense Miller was known to Korean as traditional medicine that has effective components for strengtherning function of human body, especially liver. To study characteristics of the wine and Yakju made by fruit Lycium chinense Miller, general components such as organic acid, methanol, ester, fusel oil and $SO_2$ were analyzed after storing them for 10 and 20 days at $20^{\circ}C\;and\;30^{\circ}C$, respectively. Organic acid contents of the wine were mainly lactic, malic, tartaric and acetic acid. Ester and fusel oil contents of the wine were $4.0{\sim}5.0\;mg%$ and $12{\sim}30\;mg%$, respectively, and the values were smaller than those of the Yakju. Methanol content of the wine was $25{\sim}27\;mg%$. Storage temperature in terms of the quality of the wine and Yakju was better in $20^{\circ}C\;than\;30^{\circ}C$. Treatment of the wine and Yakju either by adding 100 ppm of $SO_2$ or heating at $60^{\circ}C$ for 30 min was better in quality than control for storage.

안드로이드기반 스마트폰을 이용한 승강기 안전진단 시스템 설계 및 구현

최성현,김종수,김태석,Choi, Sung-Hyun,Kim, Jong-Soo,Kim, Tai-Suk 한국정보통신학회 2012 한국정보통신학회논문지 Vol.16 No.1

논문에서는 승강기의 자체점검 또는 안전검사를 효율적으로 수행할 수 있는 안드로이드 스마트폰 애플리케이션을 설계하고 구현하는 방법을 제안한다. 현재 승강기 자체점검은 점검자가 전반적인 승강기상태를 확인한 후 양식에 맞추어 수작업으로 기록하는 방법을 사용하고 있다. 본 논문에서는 승강기의 유지보수산업을 분석한 후, 안드로이드 OS를 사용하는 스마트폰에서 효율적인 자체점검업무를 진행하기 위한 시스템 설계방법을 소개한다. 승강기 자체점검에 스마트폰을 이용함으로써 자체점검의 품질을 향상시키고, 안전항목에 대한 정보 데이터베이스를 구축하여 이력을 관리할 수 있다는 장점이 있다. This thesis suggests how to design and implement an Android smart phone application which can perform self check or safety inspection of lifts effectively. The safety checks of lifts go in the way that inspectors check the lifts' conditions generally and record manually following a form at the moment. This thesis analyses lift maintenance industry and introduces how to design a system to proceed effective self check using a smart phone with Android OS. By using a smart phone to check lifts, we can have advantages to improve the quality of self check and maintain careers establishing information database about safety items.

폐경 전후 여성에서 요추골밀도의 예측인자

최성현 ( Sung Hyun Choi ),황다경 ( Da Kyoung Hwang ),송혜령 ( Hye Ryoung Song ),노해정 ( Hae Jeong Noh ),강진이 ( Jin Yi Kang ),최다혜 ( Da Hye Choi ),최희정 ( Hee Jeong Choi ) 대한폐경학회 2009 대한폐경학회지 Vol.15 No.2

연구목적: 이 연구는 폐경 전, 후 여성에서 요추골밀도의 예측인자를 알아보고, 이들 여성에서 낮은 골밀도 (T-score<-2.0)와 관련 있는 인자들을 조사하였다. 연구재료 및 방법: 건강 증진센터에 내원한 21세 이상의 여성 중 폐경 전 여성 1,367명, 폐경 후 여성 1,107을 대상으로 병력, 생활습관을 조사하고, 검사실검사와 요추골밀도를 측정하였다. 폐경 전 후 여성에서 요추골밀도를 예측하는 인자는 다중회귀분석을, 낮은 골밀도에 영향을 주는 인자는 로지스틱회귀분석을 이용하여 분석하였다. 결과: 폐경 전 여성에서는 요추골밀도는 신장, 체중, 체질량지수, 체지방량, 허리둘레, 수축기혈압, 맥박수, 알칼리포스파타제, 저밀도지방단백, 공복 혈당, 공복 인슐린, 호마지수, 당화 혈색소, 요산 및 호모시스테인 수치와 관련이 있었으며, 폐경 후 여성에서는 나이, 신장, 체중, 체질량지수, 체지방량, 허리둘레, 맥박수, 알칼리포스파타제, 요산 및 호모시스테인 수치와 관련이 있었다. 폐경 전 여성에서는 나이, 체중, 맥박수, 당화혈색소, 호모시스테인이 요추골밀도를 예측하는 인자였고 (R2=0.13), 폐경 후 여성에서는 나이, 체중 및 요산치가 요추골밀도를 예측하는 인자였다(R2=0.14). 낮은 골밀도를 (T-score<-2.0)와 관련이 있는 인자는 폐경 전 여성에서 나이, 체중, 맥박수, 알칼라인포스파타제 및 당화혈색소 등이었고, 폐경 후 여성에서는 나이, 체중, 알칼리포스파타제, 요산치가 낮은 골밀도와 연관이 있었다. 결론: 폐경 전 여성에서는 체중이, 폐경 후 여성에서는 나이가 요추골밀도에 있어 다른 인자들보다 중요도나 예측 정도에 있어 상대적인 영향이 더 컸을 뿐 아니라, 낮은 골밀도와도 관련이 있는 것으로 나타났다. Objectives: The objective was to determine predictors of lumbar spinal bone mineral density (BMD) in pre- and postmenopausal women. Also, we investigated factors that affect low BMD (T-score<-2.0). Methods: We analyzed the data of 2,474 women over the age of 21 who visited the Health Promotion Center. Personal and medical history was collected. Physical examination and laboratory tests were performed. LS BMD was measured using dual-energy X-ray absorptiometry. We evaluated predictors of LS BMD using multiple regression analysis. Logistic regression analysis was used to determine factors affecting low BMD. Results: In premenopausal women, LS BMD was correlated with height, weight, body mass index (BMI), body fat%, waist, systolic blood pressure, pulse rate, alkaline phosphatase (ALP), low density lipoprotein cholesterol, fasting glucose, insulin, HOMA-IR, HbA1C, uric acid, and homocysteine levels. In postmenopausal women, LS BMD was correlated with age, height, weight, BMI, body fat%, waist, pulse rate, ALP, uric acid, and homocysteine levels. Among premenopausal women, age, weight, pulse rate, HbA1C, and homocysteine levels were predictors of LS BMD (R2=0.13) and among postmenopausal women, age, weight, and uric acid levels were predictors (R2=0.14). Factors affecting low BMD were age, weight, pulse rate, ALP, and HbA1C in premenopausal women, and age, weight, ALP, and uric acid in postmenopausal women. Conclusion: In premenopausal women, weight was a major predictor of LS BMD. On the other hand, age was the strongest predictor of LS BMD in postmenopausal women.

2001년도 공동 춘계 학술발표회 논문집 : G. 발표장 ; 빗물이용 : 강우시 합류식 하수관거의 유출특성 및 찻집유량 산정

최성현 ( Sung Hyun Choi ),최승철 ( Seung Chol Choi ),원철희 ( Chul Hee Won ),김병욱 ( Byoung Ug Kim ),임재명 ( Jay Myoung Rim ) 한국물환경학회 ( 구 한국수질보전학회 ) 2002 공동 추계학술발표회 Vol.2002 No.-

최적화 하이퍼 파라미터의 XGBoost 학습자 기반 배깅 모델을 활용한 태양광 출력 예측

최성현(Sung-hyeon Choi),허진(Jin Hur) 대한전기학회 2020 전기학회논문지 Vol.69 No.7

As the world is aware of the problem of greenhouse gas emissions, the trend of generating energy source has been changing from conventional fossil fuels to sustainable energy such as solar and wind. In order to reduce greenhouse gas emissions, the ratio of renewable energy sources should be increased. However, renewable energy sources highly depend on weather conditions and it has intermittent generation characteristics, thus embedding uncertainty and variability. As a result, it can cause variability and uncertainty in the power system, and that is why it is essential to have accurate forecasting technology of renewable energy to address this problem. We proposed a bagging model which is using an ensemble model as a base learner and what we set for the base learner is a XGBoost. Results showed that ensemble learner-based bagging models averagely have lower error compared to the bagging model using single model learner. Through the use of accurate forecasting technology, we will be able to reduce uncertainties in the power system and expect improved system reliability.

손의 구조적 정보를 이용한 지문자 영상의 인식

최성현(Sung-Hyun Choi),양윤모(Yun-Mo Yang) 한국정보과학회 2001 한국정보과학회 학술발표논문집 Vol.28 No.1B

본 논문은 동작자가 표현하는 수화 동작 중, 지문자 영상을 2차원 영상처리에 의하여 인식하는 방법을 제안한다. 손은 개인에 따라 변량이 존재하고 같은 동작을 표현하더라도 항상 일정하지 않기 때문에, 지문자 인식을 위하여 손의 구조적인 정보를 이용한다. 추출된 손 영역을 입력으로 하여 손의 외곽 정보를 이용한 MAT(Medial Axis Transform)를 수행한다. 여기에서 나온 골격의 변화에 따라 각각 손가락에 해당하는 2번 쇽(Shock)과 손 바닥에 해당하는 4번 쇽의 관계에 의하여 지문자를 인식한다. 이러한 구조적인 정보를 이용함으로써 개인에 의해 나타나는 표현의 차이를 제거할 수 있고, MAT를 이용할 때 나타나는 외곽영역의 잡음에 의한 구조 변화에도 안정적으로 대처할 수 있다. 제안한 알고리즘을 이용하여 31개의 단순 지문자에 대한 270개의 입력영상을 실험한 결과 81.1%, 모양이 흡사한 지문자를 통합하여 26개의 지문자로 식별할 경우에는 91.1%의 인식율을 나타내었다.

原料의 種類와 形態에 따른 Aspergillus oryzae 麴의 生理活性 및 酸素力

최성현(Seong Hyun Choi),정재홍(Jae-Hong Jeong),이상덕(Sang Duck Lee),손화영(Hwa Young Son),성창근(Chang Sung),오만진(Man Jin Oh),김성렬(Seung Yeol Kim) 충남대학교 농업과학연구소 1997 농업과학연구 Vol.24 No.2