삼화탕(三化湯)이 중간대뇌동맥 결찰로 유발된 뇌허혈에 미치는 영향

정승현,박인식,신길조,이원철,김동은,Jeong, Sung-Hyun,Park, In-Sick,Shin, Gil-Cho,Lee, Won-Chul,Kim, Dong-Eun 대한한방내과학회 2001 大韓韓方內科學會誌 Vol.22 No.2

The purpose of this investigation is to evaluate the effects of Samwha-tang(三化湯) Extracts on reversible forebrain ischemia experimentally induced from the occlusion of middle cerebral artery. The volume of cerebral ischemia, the volume of cerebral edema, and the change of pyramidal neuron of the CA1 area in hippocampus through light microscopy were investigated. we obtained the following results. The volume of the control group, which had ischemic damage was 21%, and the volume of the sample group, which had ischemic damage, was 16%. The ratio of the volume of the right/left hemisphere was 117.2 in the control group, and 108.8 in the sample group. Also, the light microscopy revealed that the pyramidal cells of CA1 area in hippocampus had many damages like changes into discontinuous and unsystematic forms. But, in the sample group, the cells were less damaged compared with the control group.

분산구동 방식 다두자수기의 동기 모션 제어 시스템 설계에 관한 연구

정승현,박주태,Jeong, Seong-Hyun,Park, Ju-Tae 한국섬유공학회 2013 한국섬유공학회지 Vol.50 No.6

This thesis proposes a center distributed embroidery machine with a maximum speed of 1,500 rpm, 52 productivity heads, and capability to produce large-sized embroidered goods. In addition, the use of a velocity and two-axis synchronous position controller with a DOB (disturbance observer) is proposed for minimizing disturbances due to needle cams. Specifically, for the center distribution experiment, we used two conventional, 26-head, 1,500-rpm embroidery machines and showed that the proposed controller can ensure stable operation of the simulated 52-head embroidery needlework at 1,500 rpm.

H₂O₂/O₃ AOP와 UASB 공정을 이용한 매립지 침출수 처리(I) - H₂O₂/O₃ AOP 전처리 및 질소원에 따른 침출수별 처리특성 -

정승현,정병곤,Jeong, Seung Hyun,Jeong, Byung Gon 한국물환경학회 2005 한국물환경학회지 Vol.21 No.6

In order to treat leachate from aged landfill site effectively, removal of biologically recalcitrant organic matter and denitrification efficiency were evaluated through the combination of $H_2O_2/O_3$ AOP pretreatment process and UASB process. The results can be summarized as follows. In case of leachate having low COD/N ratio from aged landfill site, it is possible to increase available COD for denitrification in nitrate utilizing denitrification and nitrite utilizing denitrification both by enhancing biodegradability of recalcitrant organic matter as applying $H_2O_2/O_3$ AOP to pretreatment process. In this experiment, it is found that available COD for denitrification can be increased to 1.0 and 0.4 g/day, respectively. Comparison has been made between requiring COD and available COD for denitrification in each experimental stages. It is expected that high rate of denitrification can be achieved with leachate from young landfill site because higher amount of available COD for denotrification is present in the leachate than the amount of requiring COD for denitrification. Especially, In leachate from aged landfill site with low COD/N ratio, it can be concluded that denitrification using nitrite nitrogen can enhance overall denitrification performance efficiently because denitrification using nitrite nitrogen requires less amount of carbon source than denitrification using nitrate nitrogen. Comparing the biogas production rate and nitrogen content of biogas under the condition of same amount of nitrate and nitrite addition, biogas production and nitrogen content of biogas are increased during denitrification after $H_2O_2/O_3$ AOP pretreatment process. Therefore, it can be confirmed that COD/N ratio in the leachate is increased. Applying $H_2O_2/O_3$ AOP as pretreatment system of landfill leachate seems to have little economic benefit because it requires additional carbon source to denitrify ammonia nitrogen in leachate coming from aged landfill site. However, it is possible to apply this pretreatment process to leachate from old landfill site in view of AOP process can achieve removal of biologically recalcitrant organic matter and increase of available COD for denitrification simultaneously.

목향(木香) 및 사향(麝香)이 저산소증 유발 배양 대뇌신경세포에 미치는 영향

정승현,신길조,이원철,문일수,류도균,Jeong Sung-Hyun,Shin Gil-Cho,Lee Won-Chu,Moon Il-Su,Ryu Do-Kyun 대한한방내과학회 2003 大韓韓方內科學會誌 Vol.24 No.2

Objectives : The purpose of this investigation is to evaluate the effects of Aucklandiae Radix Moschus(木香 麝香)and to study the mechanism for neuronal death protection in hypoxia with Embryonic day 20 (E20) cortical cells of a rat (Sprague Dawley). Methods : E20 cortical cells used in this investigation were dissociated in Neurobasal media and grown for 14 days in vitro (DIV). On 14 DIV, Aucklandiae Radix Moschus(木香 麝香) was added to the culture media for 72 hrs. On 17 DIV, cells were given a hypoxic shock and further incubated in normoxia for another three days. On 20 DIV, Moschus(麝香)'s effects for neuronal death protection were evaluated by LDH assay and the mechanisms were studied by Bcl-2, Bak, Bax, caspase family. Results : This study indicate that Aucklandiae Radix(木香)'s effects for neuronal death protection in normoxia and Scutellariae Radix(麝香)'s effects for neuronal death protection in hypoxia were confirmed by LDH assay in culture method of Embryonic day 20(E20) cortical neuroblast. Moschus(麝香)'s mechanism for neuronal death protection in hypoxia is to increase the anti-apoptosis protein Bcl-2. Conclusions : It may be reasonable to propose that Moschus(麝香) protects delayed neuronal death in hypoxia by increasing Bcl-2, thereby reducing mitochondrial permeability transition(PT) pores, the cytochrome c channels.

메릴랜드주 교차로

정승현,이석홍,Jeong, Seung-Hyeon,Lee, Seok-Hong 한국도로학회 2001 도로포장공학회지 Vol.3 No.4

이형성 협심증의 임상상

강정아(Jeong A Kang),이유선(Yeu Seon Lee),정승현(Seung Hyeon Jeong),이정우(Jeong Woo Lee),김보영(Bo Yeong Kim),임대승(Dea Seung Im),이민수(Min Soo Lee),김정희(Jeong Hee Kim),정준용(Jun Young Jeong),최시완(Si Wan Choi),정진옥(Jin Ok J 대한내과학회 2002 대한내과학회지 Vol.63 No.2

목적: 우리나라는 이형성 협심증의 발생 빈도가 높음에도 불구하고 임상상과 예후에 대한 연구가 부족한 실정이다. 이에 본 조사는 이형성 협심증으로 진단을 받은 환자를 대상으로 그 빈도와 임상상 그리고 예후에 대해 연구 조사하였다. 방법: 1995년 1월부터 2000년 7월까지 흉통을 주소로 충남대학교병원 순환기 내과에 입원하여 관상동맥 조영술를 시행한 결과 관상동맥의 내경의 협착이 50% 미만이며 에르고노빈(ergonovine)8, 9) 유발 검사로 이형성 협심증으로 진단된 178명을 대상으로 하였다. 결과: 1) 관상동맥질환자 중 이형성 협심증 환자의 빈도는 13.2%로 높았다 2) 이형성 협심증의 위험인자는 흡연이 가장 많았다. 3) 이형성 협심증의 임상상은 대부분 불안정형 협심증의 양상이었고, 13.2%의 환자는 급성심근경색의 임상상을 보였다. 4) 흉통의 발생 시간대는 대부분 새벽이었고, 흉통의 지속시간 평균 11분으로 일반 협심증보다 길었다. 5) 흉통이 없을 때 검사한 심전도는 대부분에서 정상이었고, 운동부하 심전도검사는 76%에서 음성소견을 보였다. 6) 이형성 협심증의 진단에 에르고노빈 유발 관상동맥 조영술은 안전하고 유용한 검사이다. 7) 이형성 협심증의 치료에 칼슘길항제와 나이트레이트제제는 효과적인 약물이다. 8) 이형성 협심증의 예후는 비교적 양호하나 임의로 약물이 중단된 상태에서 심장사 할 수 있다. 따라서 이형성 협심증 환자는 흉통 발생에 대비한 나이트레이트의 준비가 필요하다. 결론: 본 조사에서는 관상동맥질환자의 13.2%가 이형성 협심증 환자였고, 이들은 약물 치료에 대한 효과와 예후가 비교적 양호하였다. 그러나 2.8%의 환자에서 심정지나 심장사가 발생하여 흉통 발생시에 적절한 나이트레이트제제의 사용이 필요하겠다. Background: Coronary artery spasm plays an important role in the pathogenesis of variant angina. However the precise mechanism (s) and the clinical characteristics of variant angina remain to be elucidated. We investigated the clinical characteristics and diagnostic features of variant angina. Methods: The clinical characteristics and coronary angiographic findings were analyzed in 178 patients with angiographically documented coronary artery spasm, which developed spontaneously or was provoked by the admistration of intravenous ergonovine maleate. All patients were followed for at least 1 year or more or until their death. Results: One hundred and eleven patients complained of chest pain which developed especially at night and in the early morning. One hundred and thirty three patients (74.7%) were smokers. The electrocardiographic findings at the time of admission showed no changes in 147 cases (82.6%), testes showed ST segment elevation in 22 cases (12.4%), ST segment depression in 2 cases (1.1%), T wave inversion in 7cases (3.9%). The treadmill test was performed in 135 cases, ST segment elevation was noted in 6 patients (4.4%) and ST segment depression in 18 patients (13.3%). All of the other results were within normal range. The ergonovine provovative tests for coronary spasms were safe and effective. The right coronary artery was the most prevalent site of coronary artery spasm. Drug treatment was applied initially to all patients, but only 115 patients (64.5%) received the follow-up. Of these three died from cardiac arrest. The rate of cardiac death was low (1.7%) in patient, which made it difficult to know the risk factors for the cardiac deaths. Two (1.1%) had cardiac arrest. They didn't take any medication. Patients with variant angina usually responded well to nitrates and calcium antagonists. Thus nitrates and calcium antagonists are useful in preventing attacks and abolished attacks of variant angina. Conclusion: In this study, 13.2% of coronary artery disease was variant angina. The effectiveness of drug therapy and the prognosis of the patients was quite good in the group. But when chest pain happens, the adequate use of nitrate agents is needed because of cardia arrest or cardiac death in 2.8% of the patients. (Korean J Med 63:195-202, 2002)

온도 제한조건을 고려한 이동통신 모듈의 히트싱크 최적설계

정승현(Seung-Hyun Jeong),정현수(Hyun-Su Jeong),이용빈(Yongbin Lee),최동훈(Dong-Hoon Choi) 대한기계학회 2011 大韓機械學會論文集A Vol.35 No.2

최근 이동통신 가입자의 증가로 인해 기지국의 수요도 증가하게 되었다. 하지만 기지국 설치 장소의 부족으로 인해 이동통신모듈의 크기가 소형화 되어야 할 필요성이 생겼다. 이동통신모듈의 소형화를 위해서는 모듈 겉면에 부착된 히트싱크의 크기가 소형화 되어야 한다. 또한 모듈의 열적 안정성을 보장하기 위해 설치된 전자부품의 온도가 허용온도보다 낮아야 한다. 이를 위해 상용 PIDO(Process Integration and Design Optimization) 툴인 PIAnO와 전산유체역학 프로그램인 FLOTHERM을 사용하여 전자부품의 온도를 허용온도보다 낮게 유지시키면서 히트싱크의 부피를 최소화하였다. 그 결과, 이동통신 모듈에 설치된 전자부품의 허용온도를 만족하면서 모듈의 부피를 41.9% 감소시킬 수 있었다. As the number of mobile subscribers has increased recently, the demand for more number of base stations has increased. However, because of the shortage of sites for constructing base stations, a mobile communication module needs to be small in size. To minimize the size of the module, the size of the heat sink attached to the outside of the module should be minimized. Furthermore, the temperature of each electronic component of the module should be lower than the allowable temperature so that thermal stability can be maintained. A commercial PIDO (process integration and design optimization) tool PIAnO and a commercial CFD (computational fluid dynamics) tool FLOTHERM are used to minimize the size of the module while the constraints on the temperatures of the twelve electronic components are satisfied. As a result of design optimization, the volume of the heat sink is reduced by 41.9% while all the constraints on the temperature of the twelve electronic components of the module are satisfied.

강화학습에 의한 선형동기 모터의 고정밀 제어

정승현(Seong Hyen Jeong),박정일(Jung Il Park) Korean Society for Precision Engineering 2011 한국정밀공학회지 Vol.28 No.12

A PID-feedforward controller and Robust Internal-loop Compensator (RIC) based on reinforcement learning using random variable sequences are provided to auto-tune parameters for each controller in the high-precision position control of PMLSM (Permanent Magnet Linear Synchronous Motor). Experiments prove the well-tuned controller could be reduced up to one-fifth level of tracking errors before learning by reinforcement learning. The RIC compared to the PIDfeedforward controller showed approximately twice the performance in reducing tracking error and disturbance rejection.

사회적 자본과 지식 창출이 공급사슬 성과에 미치는 영향

정승현 ( Seung Hyeon Jeong ),이창원 ( Chang Won Lee ) 한국생산성학회 2019 生産性論集 Vol.33 No.4

This study aims to investigate the effect of social capital and knowledge creation on supply chain performance in supply chain-based management environment. Since social capital has more important meaning than the study from the viewpoint of buyers who have conducted some studies from the viewpoint of suppliers. This study tried to prove how the role of structure of the supply chains is realized in the buyer-supplier relationship. The purpose of this study is to empirically analyze the effects of social capital and knowledge creation on supply chain performance in supply chain relationship. First, from the viewpoint of supplier, the influence of structural capital, cognitive capital, and relational capital on knowledge creation was identified. Second, the effect of knowledge creation on supply chain performance was demonstrated. Third, the mediating effect of knowledge creation was analyzed in the relationship between social capital and supply chain performance. For this purpose, a survey was conducted on employees who have worked for more than 5 years in the same sector in information and communication companies in Seoul and Gyeonggi Province. The measurement data were statistically analyzed through descriptive statistics, discriminant validity analysis, and confirmatory factor analysis, and the validity of the measurement items and the suitability of the measurement model were statistically analyzed. The research hypothesis was verified through the structural equation analysis on the research model. As a result of the analysis on demographic characteristics, the ratio of men was relatively high, with 101 men (53.7%) and 87 women (46.3%) in gender, and the distribution of age was 99 people (52.6%) under 30s, 65 people (34.6%) in 40s, and 24 people (12.7%) over 50s. The number of working years was 70 (37.2%) in 5-10 years, 47 (25.0%) in 10-15 years, 39 (20.7%) in 15-20 years, and 32 (17.0%) in 20 years or more. The largest number of companies were 101 companies (53.7%) with less than 100 employees, 51 companies (27.1%) with 100-500 employees, and 36 companies (19.1%) with more than 500 employees. The results of the analysis of the research hypothesis are as follows. First, social capital has a significant positive effect on knowledge creation. Second, knowledge creation had a significant positive effect on supply chain performance. Third, knowledge creation had a partial mediating effect on the relationship between social capital and supply chain performance. The implications of this study are as follows. First, companies should recognize the necessity of social capital and try to develop their capabilities to lead the competitive advantage that is specialized compared to competitors. Second, it is very important to establish, operate and manage more appropriate strategies in response to uncertain economic conditions. Third, the fact that knowledge creation has a significant mediating effect on the relationship between relational capital and supply chain performance explains the importance of social capital and the more important strategy among the factors affecting supply chain performance through knowledge creation. Although the effect of social capital and knowledge creation on supply chain performance was empirically verified in supply chain environment, the study results were not fully reviewed due to lack of previous studies. If these limitations are supplemented in the future, it is expected that sustainable and reasonable management plans will be devised in the uncertain management situation that is complicated and diverse enough to be unpredictable in the relationship between buyers and suppliers.

퍼지제어기를 이용한 크레인의 진동억제 및 위치제어

정승현(Seung-Hyun Jeong),박정일(Jung-Il Park) 제어로봇시스템학회 1997 제어·로봇·시스템학회 논문지 Vol.3 No.5