동기발전기 여자시스템용 고주파 PWM 컨버터 설계

장수진,류동균,원충연,이진국,배기훈,김수석 성균관대학교 2003 학술회의지원논문목록집 Vol.2003 No.-

A synchronous generator is equipped with an automatic voltage regulator(AVR), which is responsible for keeping the output voltage constant under normal operating conditions at various levels. The output voltage of Synchronous Generator is regulated constantly by field voltage control in excitation system. High frequency PWM converter (Buck converter) type excitation system for synchronous generator that can sustain proper output voltage level even at the fault condition happened. The proper operation of the proposed excitation system was verified through the simulations and the experiments.

전류제어형 PWM컨버터를 이용한 동기발전기용 여자시스템에 관한 연구

장수진,류동균,서민성,김준호,원충연,이진국 성균관대학교 2003 학술회의지원논문목록집 Vol.2003 No.-

동기발전기 출력전압은 여자시스템의 계자전류 제어에 의해 일정하게 유지된다. 고주파 PWM 컨버터(전류제어모드 buck컨버더)형태의 여자시스템은 부하변동이 발생하였을 때 동기발전기의 계자전류를 제어하게 된다. 이 논문은 정상상태 및 과도상태에서의 안정화를 개선하기 위하여 여자시스템의 설계 및 실험에 대해 다루었다. 시뮬레이션 및 실험 결과는 제안된 여자시스템이 50kW 동기발전기의 DVR에 의해 응답시간이 개선되었음을 보여주었다. The output voltage of synchronous generator is regulated constantly by field current control in excitation system. High frequency PWM converter (current control mode buck conveter) type excitation system for synchronous generator is able to control exciter current when the load change happened. This paper deals with the design and evaluation of the excitation system for a synchronous generator to improve the steady state and transient stability. The simulation and experimental results show that the proposed excitation system is able to improve the response time by the DVR(digital voltage regulator) of 5O[kW] synchronous generator.

성인병에 대한 한방치료법(증치의학과 사상의학)에 관한 연구 : 고혈압에 대한 한방치료법(중치의학과 사상의학)에 관한 연구

박동일,김영균,안창범,이인선,김종원,권정남,장경전,이인선,이성근,장용우,신영민 동의대학교 한의학연구소 1999 동의한의연구 Vol.3 No.-

We had a result of the treatment as below when is devided Korean medicine Tx.. Western medical Tx., Cooperative Tx.. 1) At the improvement of BP control, an average in Korean medicine Tx. (from 170㎜Hg/100㎜Hg to 150㎜Hg/90㎜Hg), an average in Western medical Tr. (from 170㎜Hg/100㎜Hg to 130㎜Hg/80㎜Hg), an average in Cooperative Tx.(from 180㎜Hg/110㎜Hg to 130㎜Hg/90㎜Hg), generally all pars had improvements of BP control. But it is not significant of each case. 2) At the improvement of symptoms by the apologetics, Cooperative Tx. is profitable in cases of 'GanHwa',' DamEum', 'EumYangYangHer', 'EumHer'. Korean medicine Tx. is superior in case of 'GiChe'. 3) At the improvement of symptoms by a questionnaire, Korean medical Tx., Western medical Tx., Cooperative Tx. groups had improvements, but each practice group didn't have specific significance. Only it was somewhat profitable to Korean medical Tx. in the 210㎜Hg/110㎜Hg, Western medical Tx. in the 180㎜Hg/110㎜Hg, Cooperative Tx, in the 170㎜Hg/90㎜ Hg. 4) There are the apparent improvements in patients whose BP are over 200㎜Hg of Korean medical Tx. group, whose BP are over 190㎜Hg of Western medical Tx. group and whose BP are over 170㎜Mg of Cooperative Tx. group. There are the improvement of diastolic BP in 110㎜Mg(Korean medical Tx., Western medical Tx.) and 90㎜Hg(Cooperative Tx.). 5) At the improvement of Pulse pressure, generally Pulse pressure are decreased. There are similar improvements in all of Korean medical Tx., Western medical Tx., and Cooperative Tx.. 6) At the Symptomatic approvement according to ages, Korean medical Tx., Cooperative Tx. are somewhat good for his twentieth, and Western medical Tx. is somewhat good for his forties. 7) the correlation of Obesity-grade and BP, as Obesity-grade is higher as BP is higher, but there are no similarity in the improvement. 8) At the EAV improvements, as examination into correlation with the point of 1~3th, we could get results as below. There are high improvements of DRHTM, DRALM, DLLYM, DLLIM in Cooperative Tx. There are high improvements of DRPASI, DLLARI in the Korean medical Tx. group. There are high improvements of DRFADM in Western medical Tx. group.

대전·충남지역 와병노인의 실태에 관한 연구

이동배,심운택,이태용,오장균,정성훈 충남대학교 의과대학 지역사회의학연구소 1991 충남의대잡지 Vol.18 No.1

This study was conducted to investigate the prevalence rate and the relationship between causative diseases and self-help abilities in bed ridden patients of the elderly. The study group was composed of 1.568 peoples aged 65 or more, living in Taejeon city and Chungnam provincial area. The results obtained were as follows : 1. The prevalence rate of bed ridden patients were 5.7% in male, and 4.3% in female. The rates revealed increasing basis with the ages. 2. The prevalence rate was higher in city area with 6.1% than inland and seaside area with 4.3%, 3.7% respectively. 3. The mean age of bed ridden patients were 75.9 years in male. 78. 0 years in female. The rates were variable with residential area. As the cause of bed ridden patients the cerebrovascular disease was higher in urban than rural area. 4. The mean age of causative diseases was the highest in contusion and fracture with 82.8 years. The period of bed ridding was the highest in muscular disease and arthropathy with 60.2 monthes. 5. The average score of activity of daily living was the highest in muscular disease and arthropathy and followed by respiratory disease, other disease, senility, cerebrovascular disease, contusion and fracture with decreasing basis. But most bed ridden patients did the activity of daily living similar to those of normal persons. 6. The causative diseases were diagnosed mainly in general hospital, hospital. and herb medicine. but muscular disease and senility were in self-diagnosed. 7. The helper of bed ridden patients were mainly wives or daughters in law.

흰쥐의 뇌,척수 및 신경절에서 내장기관과 관련된 신경원의 추적에 관한 미세형태학적연구 - Ⅱ. 감각신경세포체와 신경섬유의 표지부위

이창현,오인균,이동협,장극선,이무삼 대한해부학회 1996 Anatomy & Cell Biology Vol.29 No.6

택시운전기사의 요통에 관한 조사

최인수,이동배,오장균,이영수 충남대학교 의과대학 지역사회의학연구소 1991 충남의대잡지 Vol.18 No.2

This study was conducted to obtain the information on the low back pain of taxi drivers from June 15, 1990 to June 30, 1990. The target population was 414 taxi drivers in Seoul city. The results were as follows; 1. Mean age of studied drivers was 36.0 years old. 2. The prevalence rate of LBP during past one year was 54.3%, and that of sciatic pain was 19.8%. and that of recent 2 weeks was 30.7% 3. The prevalence rate of low back pain was increasing with the increasing age, and that of sciatic pain was increasing with increasing work times per 1 shift. The drivers of small taxi had lower prevalence rate of low back pain than that of medium sized taxi. 4. The prevalence rate of low back pain was high in the group of unsatisfying for his job, high score of anxiety and driving car having not-comfortable chair. 5. The variables of having significant relation with the low back pain of past one year were kinds of taxi, satisfaction for job, comfortability of chair and score of anxiety. Those with sicatic pain were work times per 1 shift, satisfaction for job, comfortability of chair and anxiety score and those of recent 2 weeks were work times per 1 shift and anxiety score.

일부 도시지역 노인들의 우울과 일상생활능력에 관련된 요인

박원규,이태용,정용준,오장균,이동배,조영채 충남대학교 의과대학 의학연구소 2002 충남의대잡지 Vol.29 No.1

This study was performed to provide the basic data and related factors available for the assessment of the degree of ADL and depression among older persons, manifesting their physical and psychological status. The subjects included the old people aged more than 65 years old who reside in urban areas. The interviews were delivered to 693 individuals in Taejon metropolitan city during the two-month period from June to July, 2000, and Zung Self-Rating Depression Scale and IADL developed by Older American Resources and Services of Duke medical college, were employed for the assessment of depression and IADL, respectively. The collected data were statistically processed by SPSSWIN(ver 10.0) and led to the following results. The degree of depression among 635 subjects showed that 26.6% had mild depression, 8.2% moderate and 0.6% severe while 64.6% were normal. In terms of IADL, 6.9% had impossible IADL when not aided by others, 37.0% needed some help, 56.0% possible IADL, and the higher depression scores, the significantly higher IADL scores. Based on general characteristics, depression scores were significantly higher in the female group, the older, the lower educated, the ones without cohabitants, without a spouse, without making expenses of living on their own, and IADL scores were lower, meaning the lower capability for performing daily activities, in the male group, the older, the higher educated, the group without a spouse, without making expenses of living on their own. Based on daily activities and psychological characteristics, depression scores were higher in the group who don't go out, who don't have recreational or friendly gatherings, who aren't satisfied with the lives of the past or present, who have a sense of isolation, and who don't have the will to live, and IADL scores were lower in the group who don't go out, who don't have recreational or friendly gatherings, who aren't satisfied with the lives of the past or present, who have a sense of isolation. and who don't have the will to live. Multiple regression analysis revealed that the explanatory variable having effects on depression symptoms included, with the explanatory power of 57.5%, the confidence in life, the degree of education, the subjective index of health, the sense of isolation, the exercise, the degree of IADL, the gender, the level of satisfaction with life, whether they eat breakfast or not, the concern about life, the smoking, the going out, the presence of spouse or not. The explanatory variables having effects, with the explanatory power of 28.9%, on IADL scores included the degree of depression symptoms, the age, the presence of friends or not, the frequency of outgoing, the level of education, the degree of obesity, the confidence in life, the level of satisfaction with life, the drinking or not. The study results showed that the higher depression scores had a tendency to be associated with the decreased capabilities of performing daily activities, and that the factors related to depression and/or IADL, included the confidence in life, the level of education, and the level of satisfaction with life. However, the more detailed and decisive results on the factors related to depression and IADL of the older persons are considered to require continuing efforts and comparisons among a variety of the older population.

Sn-xAg-0.5Cu 무연 솔더 볼의 파단특성 연구

정종설,이용성,신기훈,정성균,장동영 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-

This paper presents a study on the failure characteristics of SnAgCu lead-free solder balls. To estimate the effect of Ag, three types of SnAgCu balls are first prepared by varying the weight percent of Ag (1.0, 3.0, 4.0 wt%) and then analyzed by reliability tests such as thermal shock, high speed ball shear, and drop tests. Thermal shock test reveals that the higher the weight percent of Ag is, the longer the fatigue life becomes. To the contrary, high speed ball-shear test and drop test show that the shear strength and the fracture toughness of solder balls are inversely proportional to the weight percent of Ag, respectively. Reasons for these observations will be further investigated in the future work.

전분계 소재를 기반으로 제조한 지관용 접착제 개발

장동균(Dong-Kyun Jang),김영석(Young-Seok Kim),홍필남(Pil-Nam Hong) 한국펄프·종이공학회 2017 한국펄프·종이공학회 학술발표논문집 Vol.2017 No.4

Mechanism of the natural product moracin-O derived MO-460 and its targeting protein hnRNPA2B1 on HIF-1α inhibition

Soung, Nak-Kyun,Kim, Hye-Min,Asami, Yukihiro,Kim, Dong Hyun,Cho, Yangrae,Naik, Ravi,Jang, Yerin,Jang, Kusic,Han, Ho Jin,Ganipisetti, Srinivas Rao,Cha-Molstad, Hyunjoo,Hwang, Joonsung,Lee, Kyung Ho,Ko, Nature Publishing Group UK 2019 Experimental and molecular medicine Vol.51 No.2

<▼1><P>Hypoxia-inducible factor-1α (HIF-1α) mediates tumor cell adaptation to hypoxic conditions and is a potentially important anticancer therapeutic target. We previously developed a method for synthesizing a benzofuran-based natural product, (R)-(-)-moracin-O, and obtained a novel potent analog, MO-460 that suppresses the accumulation of HIF-1α in Hep3B cells. However, the molecular target and underlying mechanism of action of MO-460 remained unclear. In the current study, we identified heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1) as a molecular target of MO-460. MO-460 inhibits the initiation of HIF-1α translation by binding to the C-terminal glycine-rich domain of hnRNPA2B1 and inhibiting its subsequent binding to the 3’-untranslated region of <I>HIF-1α</I> mRNA. Moreover, MO-460 suppresses HIF-1α protein synthesis under hypoxic conditions and induces the accumulation of stress granules. The data provided here suggest that hnRNPA2B1 serves as a crucial molecular target in hypoxia-induced tumor survival and thus offer an avenue for the development of novel anticancer therapies.</P></▼1><▼2><P><B>Cancer: How a plant metabolite analog suppresses tumor growth</B></P><P>A synthetic analog of a chemical found in fruit suppresses tumor growth by targeting an RNA-binding protein (hnRNPA2B1) and preventing the production of a pro-cancer regulatory factor. Nak-Kyun Soung from the Korea Research Institute of Bioscience and Biotechnology, Cheongju, South Korea, and coworkers built on their previous discovery that a compound derived from a medicinal plant metabolite can suppress the activity of hypoxia-inducible factor-1α (HIF-1α). This protein, which is involved in many aspects of cancer biology, is activated in the low-oxygen microenvironments found inside tumors. The researchers show that the compound binds to a protein that helps with the conversion of HIF-1α–encoding RNA transcripts into HIF-1α proteins. Liver cancer cells treated with the compound grew slowly and produced less HIF-1α under both normal and low-oxygen culture conditions, highlighting the potential of this anti-cancer strategy.</P></▼2>