3.0T MRI에서 온도변화가 T1 및 T2 이완시간에 미치는 영향

김호현,권순용,임우택,강충환,김경수,김순배,백문영,Kim, Ho-Hyun,Kwon, Soon-Yong,Lim, Woo-Teak,Kang, Chung-Hwan,Kim, Kyung-Soo,Kim, Soon-Bae,Baek, Moon-Young 대한디지털의료영상학회 2013 대한디지털의료영상학회논문지 Vol.15 No.2

Purpose : The relaxation times of tissue in MRI depend on strength of magnetic field, morphology of nuclear, viscosity, size of molecules and temperature. This study intended to analyze quantitatively that materials' temperatures have effects on T1 and T2 relaxation times without changing of other conditions. Materials and Methods : The equipment was used MAGNETOM SKYRA of 3.0T(SIEMENS, Erlagen, Germany), 32 channel spine coil and Gd-DTPA water concentration phantom. To find out T1 relaxation time, Inversion Recovery Spin Echo sequences were used at 50, 400, 1100, 2500 ms of TI. To find out T2 relaxation time, Multi Echo Spin Echo sequences were used at 30, 60, 90, 120, 150, 180, 210, 240, 270 ms of TE. This experiment was scanned with 5 steps from 25 to $45^{\circ}C$. next, using MRmap(Messroghli, BMC Medical Imaging, 2012) T1 and T2 relaxation times were mapped. on the Piview STAR v5.0(Infinitt, Seoul, Korea) 5 steps were measured as the same ROI, and then mean values were calculated. Correlation between the temperatures and relaxation times were analyzed by SPSS(version 17.0, Chicago, IL, USA). Results : According to increase of temperatures, T1 relaxation times were $214.39{\pm}0.25$, $236.02{\pm}0.87$, $267.47{\pm}0.48$, $299.44{\pm}0.64$, $330.19{\pm}1.72$ ms. T2 relaxation times were $180.17{\pm}0.27$, $197.17{\pm}0.44$, $217.92{\pm}0.39$, $239.89{\pm}0.53$, $257.40{\pm}1.77$ ms. With the correlation analysis, the correlation coefficients of T1 and T2 relaxation times were statistically significant at 0.998 and 0.999 (p< 0.05). Conclusion : T1 and T2 relaxation times are increased as temperature of tissue goes up. In conclusion, we suggest to recognize errors of relaxation time caused local temperature's differences, and consider external factors as well in the quantitative analysis of relaxation time or clinical tests.

삼음삼양(三陰三陽)의 종화규율(從化規律)에 관한 연구(硏究)

김호현,Kim, Ho-Hyun 대한동의생리학회 1999 동의생리학회지 Vol.14 No.2

This study was undertaken to define the expression rule of six vital substances for human life(六氣) in Meridians and the rule of following of three ${\breve{U}}m$ and three Yan. In order to investigate the expression rule of six vital substances for human life(六氣), incident(標)-fundamental(本) and Ki of middle energizer(中氣) of three ${\breve{U}}m$ and three Yang(三陰三陽) were reviewed. 1, The rule of following is formed centering around fundamental Ki(本氣) between incident(標) and fundamental(本). And in case the ${\breve{U}}m$ and Yang (陰陽) disposition of incident(標) and fundamental(本) is different, whether the ${\breve{U}}m$ and Yang(陰陽) disposition of incident(標) and fundamental(本) is same as those of Ki of middle energizer(中氣), is the key point in following fundamental and activating of the vital energy(氣化). 2. As twelve channels(十二經脈) have not only fundamental Ki(本氣) but also Ki of middle energizer(中氣) at the same time, in expression of six vital substances for human life(六氣), if the fundamental Ki(本氣) is stronger, fundamental Ki(本氣) can be expressed or if the fundamental Ki(本氣) is weaker, Ki of middle energizer(中氣) can be expressed. 3. Twelve channels which is connected with each other through the relation of the interior and the exterior can be regarded as a system, in which Wind(風) and Fire(火), Dryness(燥) and Dampness(濕), Cold(寒) and Heat(熱) maintain balance through mutual control. 4. We can see that in the disease caused by the unbalance of six vital substances for human life(六氣), expression of six pathogenic factor and controlment of six vital substances for human life(六氣) are made up after the following one in the rule of following(從化規律).

사립유치원 경력 교사의 사직에 담긴 살아가는 이야기에 관한 내러티브 탐구

김호현(Kim, Ho-Hyun) 한국영유아교원교육학회 2020 유아교육학논집 Vol.24 No.1

이 연구는 10년의 유치원 경력을 가진 한 선생님의 사직 전과 후의 정체성 변화 과정과 사직의 의미를 내러티브 탐구의 살아가는 이야기와 개인적·전문적 지식 전경의 틀로 들여다보았다. 이를 위해 10년 동안 몸담았던 유치원을 그만두고 대학원에 진학한 김선생님과 아홉 차례 대화를 나누었고, 내러티브 탐구 방식으로 현장, 중간, 연구텍스트를 구성하였다. 김선생님은 교사 시절 개인적 전경과 전문적 전경이 충돌하는 과정에서 좌절과 허탈함을 겪었으나 이 충돌은 김선생님에게 교사가 되기 전 상상했던 유아를 변화시키는 좋은 교사가 될 기회가 되었고, 부모교육 강사의 꿈을 가지고 사직을 한 뒤 대학원에 진학하였다. 가르치는 자에서 배우는 자로, 유치원에서 대학원으로 역할과 장소가 바뀌고, 새로운 관계가 만들어지고, 경제적 어려움과 차별의 벽에 좌절하면서 정체성에도 변화가 생겼지만 유아를 변화시키는 좋은 교사가 될 것이라는 중추의 정체성을 유지함으로써 교사 시절부터 지금껏 전문적 전경의 삶을 살고 있다. 그의 사직에 담긴 살아가는 이야기는 더 큰 꿈을 향해 여행하는 성장에 관한 이야기이고, 유아를 위해 무엇을 할 것인가에 관한 답을 찾는 과정이었다. The study looked inside the changing identity of a former kindergarten teacher with 10 years of career experience before and after her resignation and the meaning of her resignation within the frames of stories to live by and personal-professional knowledge landscapes. Nine deep dialogues with the teacher, Kim, were conducted and a constructed field, interim, and final search text were made. Kim went through frustration and letdowns in the middle of conflicts between the personal and professional landscapes but this conflict was a good chance for her to be a good teacher who changed the children for the better, a story imagined before she became a teacher. She chose to resign and attend graduate school. Her identity changed as her role, place, and relationships shifted from teacher to learner, from the kindergarten to the tertiary-level classroom and being frustrated due to financial difficulties and barriers of discrimination. However sustaining her core identity as a good teacher who changed children for the better, she has been living on the professional landscape linked from the rookie teacher. Stories to live by embedded in Kim’s resignation stories are about the story of one teacher’s travelling for a better dream and a course of answering what to do for the children.

혈부축어탕이 Triton WR-1339에 의한 고지혈증 유발 생쥐 간조직내 지질 축적 억제에 미치는 영향

김호현,방혜정,강윤호,박인식,안상현,김진택,이해풍,Kim, Ho-Hyun,Bang, Hyui-Jeng,Gang, Yun-Ho,Park, In-Sick,Ahn, Sang-Hyun,Kim, Jin-Tack,Lee, Hai-Poong 대한동의생리학회 1999 동의생리학회지 Vol.14 No.2

After Triton WR-1339 (TX; 600mg/kg) intraperitoneal injection, hepatic tissues of ICR mice were intragastric injected with Hyulboochucketang extract(HCE; 3.3ml/kg/day) were observed to investigate the suppressive effect of lipid accumulation that evoke by the antihyperlipidemic effect of HCE. These hepatic tissues were fixed in fromol-calcium solution and were cryocut. These tissues stained by H&E for general morphology, sudan black B for lipid and perchloric acid-naphthoquinone(PAN) method for cholesterol. After TX treatment, the increase of hepatocyte having meshlike cytoplasm(HHMC) were shown in all hepatic lobules and the hepatic plates were disappeared in the aggregative region of HHMC. The number of blue black colored lipid drop and dark green colored asterisk shaped cholesterol particle in hepatic cytoplasm were increased and the size of lipid drop and cholesterol particle were enlarged. But, in HCE-treated mice, the HHCM were disappeared and hapatic plate were rearranged. The number of lipid drop and cholesterol particle were decreased than TX-treated mice and the size of lipid drop and cholesterol particle were diminished. As results indicated that the HCE work on the suppression of lipid accumulation in hepatic tissue of hyperlipidemic mice caused by disturbance of lipid metabolism.

네일 숍(Nail Shop) 근무자의 휘발성유기화합물류 노출 및 자각증상평가

김호현(Ho-Hyun Kim),심정희(Jung-Hee Shim),박창수(Chang-Su Park),양지연(Ji-Yeon Yang),임영욱(Young-Wook Lim),신동천(Dong-Chun Shin) 한국실내환경학회 2010 한국실내환경학회지 Vol.7 No.2

The purpose of this study is to investigate the potential exposure of chemicals from the working environment of nail shops and determine health-related symptoms from the nail shop workers by self-reporting questionnaire. A total of 54 nail shop workers from 15 different locations were asked to conduct a survey concerning their working environment. VOCs (including toluene and nine other substances) and aldehyde(including formaldehyde and four other substances) detected. We studied on the relationship between the environmental concentration of chemical substances and the self-reported symptoms of nail shop workers. There was a significant relationship between the neck pain and substances such as 2- propanol, benzene, toluene, n-buthylacetate, ethylbenzene, and xylene (p<0.05).

IoT 기반 시내버스 실내공기질 노출 특성

김호현(Ho-Hyun Kim) 한국환경보건학회 2022 한국환경보건학회지 Vol.48 No.1

Background: Air pollution is increasing together with industrialization and urbanization. In order to reduce air pollution, public transportation is recommended rather than private cars, and the number of passengers using public transportation is increasing accordingly. This study observes the concentration of indoor pollutants in city buses over time. Through this means, we intend to suggest a plan to manage the indoor air quality in city buses. Objectives: The concentration of indoor pollution in public transportation was investigated from April 2021 to January 2022. Based on this, we evaluated the exposure to indoor pollutants. Methods: Six city bus lines in an industrial city were selected for the research, and indoor pollution was measured through IoT (Internet of Things)-based sensor-type measuring devices. The concentration of pollutants was measured every minute, and statistical data were constructed based on the measurement results. Results: In all the city buses studied, the average concentration of pollutants were below the guidelines. However, some measurement results showed cases of exceeding the guidelines. As a result of the analysis by time zone, there were more cases in which pollutants exceeded the standard value during rush hour compared to at other times. A risk assessment for PM10 was performed by evaluating the excess mortality risk from exposure and the risk from inhalation exposure. Conclusions: All measured indoor pollutants in the city buses did not exceed the guidelines. Also, the risk assessment results were found to be within the level of safety. However, if a city bus is used for a long time, there is a possibility that there may be an impact on the human body due to inhalation exposure, so additional management is required.

정부의 R&D 지원과 벤처기업의 스톡옵션제도 활용이 벤처기업의 혁신성과에 미치는 영향

김호현 ( Kim Ho-hyun ),박형준 ( Park Hyung-jun ) 한국벤처혁신학회 2024 벤처혁신연구 Vol.7 No.1

본 연구는 정부의 R&D 지원과 벤처기업의 스톡옵션제도 활용이 벤처기업의 혁신, 즉 혁신역량 및 혁신성과에 미치는 영향을 분석하고자 하였다. 이를 위해 국내 벤처확인기업을 대상으로 진행된 벤처기업정밀실태조사 자료를 활용해 부분최소제곱 구조방정식모델링(PLS-SEM) 방법으로 실증분석을 실시하였다. 분석 결과, 정부 R&D 지원의 수혜 여부는 벤처기업의 혁신역량 강화에 정(+)의 영향을 미치는 것으로 나타났으며, R&D 지원은 벤처기업의 혁신성과에도 정(+)의 영향을 미치는 것으로 나타났다. 또한 벤처기업의 스톡옵션제도 활용은 기업의 혁신역량 강화에 정(+)의 영향을 미치고, 벤처기업의 혁신성과에도 정(+)의 영향을 미치는 것으로 나타났다. 벤처기업의 혁신역량은 정부의 R&D 지원 및 벤처기업의 스톡옵션제도 활용과 기업의 혁신성과 사이를 유의하게 매개하는 것으로 나타났다. 이러한 분석결과들은 벤처기업의 혁신에 있어서 정부의 R&D 지원과 스톡옵션 제도의 활용이 의미있는 역할을 할 수 있음을 보여주며, 아울러 혁신의 프로세스에서 벤처기업의 혁신역량이 중요한 의미가 있음을 보여준다. 따라서 벤처기업에 대한 R&D 지원의 기조를 꾸준히 이어나가면서 동시에 기업의 역량강화를 지원하는 다면적 정책수단을 투입할 필요가 있으며, 스톡옵션제도의 활성화를 위한 법적·제도적 정비와 정책적 지원이 지속적으로 이루어질 필요가 있을 것으로 보인다. The purpose of this study was to analyze the effect of the government's R&D support and the use of stock options by venture companies on the innovation of venture companies, that is, innovation capabilities and innovation performance. An empirical analysis was conducted using the partial least squares structural equation modeling (PLS-SEM) method using the data from the detailed survey of venture companies conducted on domestic venture confirmation companies. As a result of the analysis, it was found that the benefit of government R&D support had a positive (+) effect on strengthening the innovation capabilities of venture companies, and R&D support also had a positive (+) effect on the innovation performance of venture companies. Next, it was found that the use of stock options by venture companies had a positive (+) effect on the reinforcement of the innovation capabilities of companies and a positive (+) effect on the innovation performance of venture companies. In addition, it was found that the innovation capabilities of venture companies significantly mediate between the government's R&D support and the use of stock options by venture companies and the innovation performance of companies. These analysis results show that the government's R&D support and the use of stock option systems can play a meaningful role in the innovation of venture companies, and also show that the innovation capabilities of venture companies have an important meaning in the process of innovation. Therefore, it is necessary to continue the stance of R&D support for ventures and at the same time to introduce multi-faceted policy measures to support corporate capacity building, and legal and institutional maintenance and policy support to revitalize the stock option system need to be continuously provided.

비장 절제술 후에 확진된 비장의 과오종

김호현(Ho Hyun Kim),박은규(Eun Kyu Park),성진식(Jin Shick Seoung),허영회(Young Hoe Hur),고양석(Yang Seok Koh),김정철(Jung Chul Kim),조철균(Chol Kyoon Cho),김현종(Hyun Jong Kim) 한국간담췌외과학회 2010 한국간담췌외과학회지 Vol.14 No.4

Hamartoma of the spleen is a rare benign lesion and the pathogenesis of this is not completely understood. It is usually incidentally discovered during an operation or autopsy. Since the first report in 1861 by Rokitansky, less than 150 cases of splenic hamartoma have been documented in the literature to date. The majority of the patients with this tumor are asymptomatic. However, a few of these lesions are associated with clinical features such as hypersplenism, cirrhosis of the liver and spontaneous splenic rupture. Because there are no specific symptoms, tumor markers or radiologic results, it is usually difficult to make a diagnosis before surgery and the specimen pathology. We report here on three cases of splenic hamartoma (a 33-year-old man associated with thrombocytopenia, a 29-year-old woman with a 6-month history of left upper quadrant abdominal pain and a 43-year-old man with synchronous hepatocellular carcinoma) and we review the relevant literature.

[화학] 이온 크로마토그래피용 모세관 컬럼의 개발

김호현(Ho-Hyun Kim),표동진(Dong-Jin Pyo) 한국분석과학회 1999 분석과학 Vol.12 No.6

어린이 주요활동공간의 휘발성유기화합물류 노출로 인한 건강위해성 평가 : 초등학교 및 학원을 중심으로

김호현(Ho-Hyun Kim),임영욱(Young-Wook Lim),이청수(Chung-Soo Lee),김태훈(Tae-Hoon Kim),박주희(Ju-Hee Park),전준민(Jun-Min Jeon),신동천(Dong-Chun Shin),양지연(Ji-Yeon Yang) 한국실내환경학회 2011 한국실내환경학회지 Vol.8 No.4

This study was to assess the lifetime cancer and non-cancer risk on exposure to volatile organic compounds This study was assessed the lifetime cancer and non-cancer risk of volatile organic compounds (VOCs) exposure in young children at elementary-schools and academies in Korea. The samples were collected at children's facilities (50 elementary-schools and 42 academies) in summer (Aug ~ Sept, 2008), winter (Dec 2008 ~ Feb, 2009) and Spring (Mar ~ Apr, 2009) periods, and analyzed by GC-MSD. We estimated the lifetime excess cancer risks (ECRs) of benzene and the hazard quotients (HQs) of non-carcinogens toluene, ethylbenzene, xylene and styrene. In addition, for carcinogens, the excess cancer risk (ECR) was calculated by considering the process of deciding cancer potency factor (CPF) and age dependent adjust Factor (ADAF) from the data in adults. The average ECRs of benzene for young children were 1×10⁻⁷~1×10⁻⁹ level in all facilities. HQs of four non-carcinogens did not exceed 1.0 for all subjects in all facilities.