곡선부 통과 차량의 동적거동 예측을 위한 주행안정성 해석

오정헌(Jeong-Heon Oh),엄범규(Beom-Gyu Eom),강부병(Bu-Byoung Kang),이희성(Hi Sung Lee) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.11

The two major factors related to the train driving safety are classified as the railway vehicle conditions and the track conditions In case of railway vehicles, there are static wheel load ratio, spring stiffness of primary and secondary suspension, effective center heights of railway vehicle, etc..and In case of tracks. there are curve radius, cant, rail irregularity, rail inclination, etc..These can influence in running stability of railway vehicle. Besides, the running speed and friction coefficient of wheel&rail are factors that influence in running stability of railway vehicle. In this study, when the railway vehicle passing through curves, the effect that has influence on running safety is examined to devise the high speed of vehicle which passing through curves which risk of derailment is high. it wished to reappear derailment mode using commercial analysis program. It achieved parts(wheelset, bogie, cars) modelling and running stability/derailment safety analysis using multibody dynamics program(ADAMS/View). Also, the dynamic behaviors of railway vehicle passing through curve are estimated by utilizing analysis results.

시뮬레이션을 이용한 고속철도 차량기지 설계 최적화

오정헌(Jeong Heon Oh),엄인섭(In Sup Um),박춘수(Choon Soo Park),이희성(Hi Sung Lee) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.11

This paper presents a simulation-based optimal design method for the design of the train depot. Because the train depot is composed of each subsystems such as car body and wheel workshop, the train is divided into car, car body and wheel for the process analysis and we design the simulation model. In simulation analysis, we consider the dependent variables and independent parameters. Therefore, the Multi Criteria Decision Making (MCDM) is used for selecting the alternatives and simulation optimization is proposed for finding the optimal design parameters of the selected alternative by using evolution strategy. The case study for the above design process is applied to the KTX-Ⅱ(High-Speed Railway) Train Depot. This paper provides a general design and analysis framework for the train depot design with using the simulation.

고관절 외전 각도가 리버스 하이퍼 익스텐션 운동 시 근활성도에 미치는 영향

오정헌(Oh, Jeong-Heon),한누리(Han, Nu-Ri),서태범(Seo, Tae-Beom) 한국체육과학회 2021 한국체육과학회지 Vol.30 No.6

The purpose of this study was to investigate whether different hip abduction angles might alternate hip extensor muscle activity in reverse hyperextension (RHE) exercise. Fourteen healthy male subjects performed RHE in 4 hip abduction angles (-10°, 0°, 15°, and 30°). Muscle activities of longissimus, gluteus maximus, gluteus medius, biceps femoris, semitendinosus, and adductor magnus were measured by surface electromyography device. One-way repeated ANOVA was used to analyze the results from each angle of muscle and the ratio of muscle activation. During the concentric phase of RHE, gluteus medius activation was greater at 15° and 30° of hip abduction angles (p<.001) than at -10 and 0°, while biceps femoris was greatest at -10° (p<.001) followed by 0°, 15°, and 30° of hip abduction angles. During the eccentric phase of RHE, gluteus medius activation was greater at 15° and 30° of hip abduction angles (p<.003) than -10°, while biceps femoris was greatest at -10° (p<.001) followed by 15° and 30°. Our findings suggest that RHE of hip abduction at 15° and 30° might be the most appropriate angle for maximizing gluteal muscle activation.

시뮬레이션 기법을 이용한 철도차량 중정비 공장 설계검증 - 디젤동차 및 발전차 중정비 공장을 중심으로 -

전병학,장성용,이원영,오정헌,Jeon, Byoung-Hack,Jang, Seong-Yong,Lee, Won-Young,Oh, Jeong-Heon 한국시뮬레이션학회 2009 한국시뮬레이션학회 논문지 Vol.18 No.3

In the railroad rolling stock depot, long-term maintenance tasks is done regularly every two or four year basis to maintain the functionality of equipments and rolling stock body or for the repair operation of the heavily damaged rolling stocks by fatal accidents. This paper addresses the computer simulation model building for the rolling stock maintenance shop for the CDC(Commuter Diesel Car) and Generator Car planned to be constructed at Daejon Rolling Stock Depot, which will be moved from Yongsan Rolling Stock Depot. We evaluated the processing capacity of two layout design alternatives based on the maintenance process chart through the developed simulation models. The performance measures are the number of processed cars per year, the cycle time, shop utilization, work in process and the average number waiting car for input. The simulation result shows that one design alternative outperforms another design alternative in every aspect and superior design alternative can process total 340 number of trains per year 15% more than the proposed target within the current average cycle time.

갑상선 악성종양 및 양성종양에서 Fra - 1 표현에 대한 연구

김용현(Youg Hyun Kim),오정헌(Jeong Heon Oh),김난희(Nan Hee Kim),최경묵(Kyung Muk Choi),김상진(Sang Jin Kim),백세현(Sei Hyun Baik),최동섭(Dong Seop Choi),이응석(Eung Seok Lee) 대한내과학회 2000 대한내과학회지 Vol.59 No.4

Background : Differential diagnosis of thyroid nodule is important in deciding treatment modality and fine needle aspiration is a good method to do so. But, sometimes, it has limitation in use because of inadequate test material and difficulty in interpreting it. Among the study of oncogene and tumor suppresor gene on the origin of thyroid tumor, expression of Fra-1, one of AP-1 system, is increased in thyroid neoplasm. So there is a possibility that it would be used as a method for differential diagnosis of thyroid nodule. We tried to know whether presence or absence of Fra-1 expression can be used as a diagnostic method in differential diagnosis of thyroid nodule using immuno- histochemical(IHC) staining method.Methods : In 4 types of thyroid tumor that was confirmed by histologic diagnosis after operation(30 cases of papillary cancer, 10 cases of follicular cancer, 16 cases of follicular adenoma, 18 cases of adenomatous goiter), IHC staining method was performed to evaluate the expression of Fra-1.Results : In papillary and follicular thyroid cancer, the expression of Fra-1 was stronger than benign thyroid tumor, but there was no difference in Fra-1 expression between two types of carcinoma. Weak expression of Fra-1 was observed in all cases of follicular adenoma, and it was also weakly expressed in 6 out 18 cases of adenomatous goiter. Conclusion : The expression of Fra-1 was stronger in thyroid cancer than in benign thyroid adenoma, but it was impossible to differentiate thyroid cancer from benign thyroid adenoma by the presence or absence of Fra-1 expression using IHC staining method.(Korean J Med 59:398-403, 2000)

2형 당뇨병 환자 혈액내 DHEA 및 DHEAS 농도와 증후군 X 및 심혈관합병증과의 관련성

김상진,김난희,김용현,최동섭,백세현,최경묵,오정헌 대한당뇨병학회 2000 Diabetes and Metabolism Journal Vol.24 No.2

Background: Insulin is known as a major factor that regulates secretion of DHEA and DHEAS. Numerous studies are exist to investigate the relationship between DHEA(S) and insulin resistance. Furthermore, numerous previous studies revealed that insulin resistance plays a major role in the pathogenic relationship between DHEA(S) and type 2 diabetes mellitus. However, number of studies to investigate the difference of levels of DHEA(S) according to the presence of syndrome X in type 2 diabetes mellitus are limited. Methods: In type 2 diabetes, aged from 40 to 70 years old, the levels of serum DHEA and DHEAS was compared between the subjects with or without syndrome X as well as the normal age and sex matched control. Furthermore, correlation between serum DHEA/DHEAS and insulin resistance, and the levels of DHEA/DHEAS according to the cardiovascular complication status was also evaluated. Results: 1. No statistical difference in serum DHEA and DHEAS was observed among the 3 groups. However, the serum DHEA and DHEAS levels were lower in type 2 diabetes with syndrome X and higher in normal control. 2. No correlation was observed between DHEA, DHEAS and insulin resistance factors. 3. No stastistical difference in serum DHEA and DHEAS was observed in type 2 diabetic patients with cardiovascular complications. However, the level of DHEA was lower in the patients with cardiovascular complications. 4. No stastistical difference in serum DHEA and DHEAS was observed according to the presence of cardiovascular complications when analysis was performed in 55 years and younger subjects. 5. The level of DHEA was lower in the presence of cardiovascular complication when only male diabetic subjects were included in the analysis, but the level of DHEAS showed no difference according to the cardiovascular complication status. Conclusion: No statistical difference of the levels of serum DHEA and DHEAS was observed according to the presence of syndrome X in type 2 diabetes patients. However, the level of serum DHEA tended to be lower in the presence of cardiovascular complications. The levels of DHEA in male diabetic subjects were lower in the presence of cardiovascular complication, thus, we suspected that DHEA may play a potential role as one of risk factors of cardiovascular complications in this subgroup.

RET 유전자 배선 돌연변이가 확인된 제2형 다발성 내분비선종증 (MEN 2A) 1예

김희영,이지연,김성범,이계원,서지아,오정헌,김신곤,최경묵,백세현,최동섭,김난희 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.5

저자들은 언니가 갑상선 종양으로 절제술을 시행받은 가족력이 있고 당뇨병의 증상으로 내원한 47세 여자 환자가 양측 갑상선 종괴와 양측 부신덩이를 동반한 다발성 내분비선종의 특징을 보여, 생화학적 검사 및 영상학적 검사로 MEN 2A로 잠정적으로 진단한 후 갑상선 전절제술 및 양측 부신제거술로 양측성갑상선수질암과 갈색세포종을 진단하고 유전자 분석에서 RET 원발암유전자의 codon 618의 돌연변이를 확인였기에 문헌 고찰과 함께 보고하는 바이다. Multiple endocrine neoplasia 2A (MEN 2A) is an autosomal dominantly inherited disease, composed of medullary thyroid carcinoma, pheochromocytoma and hyperparathyroidism. The activation of germ-line mutations in the RET proto-oncogene are responsible for MEN 2. The analysis of the RET mutations has replaced the measurement of the calcitonin level in the diagnosis of the MEN carrier state. Specific RET codon mutations correlate with the MEN 2 syndromic variant, the age at onset of the medullary thyroid carcinoma (MTC) and the aggressiveness of the MTC. Herein, our experience of a 47-year-old woman, who had a bilateral pheochromocytoma and MTC, and MEN 2A confirmed by the detection of an RET proto-oncogene mutation at axon 10 on codon 618, is reported. Her sister was found to have the same mutant gene. After a total thyroidectomy and bilateral adrenalectomy, the calcitonin and catecholamine levels were normalized, and the patient discharged without problems. This case is reported, with a review of the literature (J Kor Soc Endocrinol 18:481∼488, 2003).

11β-수산화효소 결핍에 의한 선천성 부신증식증 1예

류옥현,류혜진,박수연,권순범,박상수,김희영,이계원,서지아,오정헌,김신곤,김난희,최경묵,백세현,최동섭 대한내분비학회 2004 Endocrinology and metabolism Vol.19 No.1

저자들은 국내에서 처음으로 음핵 비대와 지속적인 질출혈을 주소로 내원한 19세 여성에서 고혈압이 동반되지 않으면서 11 -수산화효소 결핍으로 인한 선천성부신증식증을 경험하였기에 문헌 고찰과 함께 이를 보고하는 바이다. Congenital adrenal hyperplasia refers to a group of autosomal recessive disorders that is defective in the synthesis of cortisol. The enzymes most often affected are 21-hydroxylase and 11 - hydroxylase. The low levels of cortisol stimulate the pituitary gland to release ACTH. Chronic elevation of the ACTH level causes bilateral adrenal hyperplasia and a secondary increase in androgen formation. We examined a 19 year-old woman presented with clitoral hypertrophy and vaginal spotting. The subjects basal level of serum cortisol was low, but the serum levels of ACTH, 17a-hydroxyprogesterone, deoxy-corticosterone were elevated. The urinary excretions of 17-ketosteroids and 17-hydroxycorticosteroids were also increased. The karyotyping study and transrectal ultrasonography showed normal findings. The patient underwent clitoris reduction surgery and received hydrocortisone. To the best of our knowledge, this is the first case of 11 -hydroxylase deficiency in Korea (J Kor Soc Endocrinol 19:58∼63, 2004).

부신피질암과 동반된 다발성 부신경절종 1예

김상진,김난희,김용현,김애리,최동섭,백세현,최경묵,김철환,오정헌 대한내분비학회 1999 Endocrinology and metabolism Vol.14 No.3

Simultaneous oceurrence of adrenocortical tumor and pheochromocytoma is extremely rare. Coexistence of adrenal tumor and pheochromocytoma was first reported by Cope in 1952 and some other cases were reported after that. But there was no report about coexistence of adrenocortical carcinoma and paragangliomas. Recently, we experienced a case of adrenocortical carcinoma associated with multiple paragangliomas. A 35-year-old woman was admitted to the hospital because of left upper abdominal pain. A palm-sized fum tender mass was palpated at left upper quadrant. Hormonal studies revealed pheochromocytomas feature. Fmergency operation was performed because of the possibility of intemal hemorrhage of the tumor. Operator found 10 cm sized mass in left adrenal area and also the other 5 small tumors adjacent to IVC. Pathologic report revealed that adrenal mass was adrenocortical carcinoma with hemorrhagic necrosis and tumors adjacent to IVC were paragangliomas. This patient was the first case of adrenocortical carcinoma with multiple paragangliomas in the world. So we report this case with a review of literature. (J Kor Soc Endocrinol 14:599-604, 1999)