형상창성함수를 이용한 엘라스토머 조형가공시의 절삭력 해석

전진철(Jin-Chul Jun),김남전(Nam-Jun Kim),이선규(Sun-Kyu Lee) 한국정밀공학회 1998 한국정밀공학회 학술발표대회 논문집 Vol.1998 No.11월

6-PRRS 병렬형 기계의 오차해석 및 교정에 관한 연구

전진철(Jin-Chul Jun),이선규(Sun-Kyu Lee) 한국정밀공학회 1999 한국정밀공학회 학술발표대회 논문집 Vol.1999 No.11월

Anti-tumor Activity of the Ethyl Acetate Fraction from Asparagus cochinchinensis in HepG2-xenografted Nude Mice

전진미,문병철,이아영,추병길,김호경,전명숙 한국응용생명화학회 2011 Applied Biological Chemistry (Appl Biol Chem) Vol.54 No.4

Although Asparagus cochinchinensis Merrill (Liliaceae) has traditionally been used for cancer treatment, its in vivo antitumor efficacy has not been established. Anti-tumor effect of the ethyl acetate fraction of A. cochinchinensis extract (EAF-ACE) was evaluated in nude mice xenografted with human hepatocellular carcinoma (HepG2) cells. Serum biomarkers were also examined to monitor the hepatotoxicity and nephrotoxicity of EAF-ACE. HepG2-xenografted nude mice were randomly divided into untreated group, EAF-ACE-treated groups (50, 100, or 200 mg/kg), and positive control group (3 mg/kg cisplatin). All groups were assayed for tumor mass formation, apoptosis induction, and serum biomarkers. EAF-ACE treatment significantly reduced tumor growth. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay revealed EAF-ACE treatment significantly increased the number of apoptotic cells in tumors in a dosedependent manner, whereas cisplatin treatment significantly decreased tumor volumes and increased the number of apoptotic cells, and exhibited hepatotoxicity and nephrotoxicity, in contrast to EAF-ACE treatment. EAF-ACE was found to possess antitumor activities without associated hepatotoxicity and nephrotoxicity. Therefore, EAF-ACE may be effectively used as a chemopreventive agent.

토양안정재를 혼합한 녹생토의 전단강도 및 침식저항특성

오세욱,전진철,김동근,이헌호,권영철 한국지반환경공학회 2015 한국지반환경공학회논문집 Vol.16 No.12

With the rising interest in the environment, more attention on ecological restoration for damaged slope surface to restore its original state has been drawn. Generally, the most useful method is vegetation based spray work. This method uses green soil including sewage sludge, sawdust, paper sludge, and weathered granite soil. However, because there are neither accurate information nor test values about green soil, green soil is often lost by environmental factors such as rainfalls and strong winds. To solve the problem of green soil, it is necessary to prepare design standards about green soil, and conduct studies to deal with green soil loss in consideration of various variables including basic material property, soil quality of slope surface, and weather. This study was conducted in the mixture of green soil and eco-friendly soil stabilizer. With green soil, basic material property test and compaction test were conducted for the analysis on the basic characteristics of green soil. In the mixture with soil stabilizer at a certain ratio, we conducted shear strength test depending on the ratio in order to analyze the maximum shear strength, cohesion and the change in internal friction angles. Furthermore, in the mixture ratio of green soil and soil stabilizer, which is the same as the ratio in the shear strength test, an inclination of slope surface was made in laboratory for the analysis on erosion and germination rate. Finally, this study evaluated the most effective and economic mixing ratio of soil stabilizer to cope with neighboring environmental factors. According to the test, the shear strength of green soil increased up to 51% rely onto the mixing ratio of and a curing period, and its cohesion and internal friction angle also gradually increases. It is judged that the mixture of soil stabilizer was effective in improving shear strength and thereby increased the stability of green soil. 최근 산림 훼손지를 원래 상태로 되돌리기 위한 생태복원에 대한 관심이 높아지면서 인공 비탈면을 보강하면서 친환경적인 녹화가 될 수 있는 연구가 진행되고 있으며, 이러한 생태복원을 목표로 식생생육의 기반이 되는 인공토양의 조성과 관련된 많은 기술들이 개발되고 있는 추세이다. 본 연구에서는 하수오니, 톱밥, 제지슬러지, 화강풍화토가 포함되어 사용되고 있는 녹생토와 친환경적인 토양안정재를 활용하여 연구수행을 하였다. 토양안정재와 혼합된 녹생토를 이용해 기본물성실험을 통해 녹생토의 기본적인 특성을 분석하였으며, 친환경적인 토양안정재를 일정비율로 녹생토와 혼합하여 각각의 비율에 따른 전단강도실험을 수행하여 최대전단강도를 분석하고 이에 따른 점착력과 내부마찰각을 산정하였다. 그리고 녹생토와 토양안정재의 혼합비율을 전단강도실험과 동일한 조건으로 비탈면의 기울기를 적용하여 토양안정재의 혼합비율에 대한 침식률과 발아율을 분석하여 주변 환경적 요인에 대처 가능한 토양안정재의 경제적인 혼합비율을 고찰하고자 한다. 실험결과 양생기간과 안정재의 혼합률에 따라 최대 51%까지 전단강도가 증가하였으며, 실험결과를 바탕으로 내부마찰각과 점착력이 모두 상승한 점을 확인하여 안정재가 녹생토의 전단성능 과 침식저항 향상에 기여하고 있음을 확인하였다.

Finite element analysis of the impact of liner thickness and hydrodynamic limit on the penetration depth of a shaped charge warhead

강영구,전진철 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.12

In this work, an identification method for the hydrodynamic limit of shaped charge jets (SCJs) is proposed using numerical analysis. To identify the hydrodynamic limit, we consider situations where two targets of the same density but different strengths are penetrated by the same SCJ. As a result, the SCJ corresponding with the hydrodynamic theory is a jet region with a velocity larger than 4 km/s. In addition, an investigation based on the hydrodynamic limit and liner thickness indicates that the penetration capability before and after the hydrodynamic limit improves as apex thickness decreases and base thickness increases, respectively. The simple and clear identification of the hydrodynamic limit is expected to be possible using the proposed method. Accordingly, a selective and organized liner thickness design can be developed. In this work, an identification method for the hydrodynamic limit of shaped charge jets (SCJs) is proposed using numerical analysis. To identify the hydrodynamic limit, we consider situations where two targets of the same density but differen t strengths are penetrated by the same SCJ. As a result, the SCJ corresponding with the hydrodynamic theory is a jet region with a velocity larger than 4 km/s. In addition, an investigation based on the hydrodynamic limit and liner thickness indicates that the penetration capability before and after the hydrodynamic limit improves as apex thickness decreases and base thickness increases, respectively. The simple and clear identification of the hydrodynamic limit is expected to be possible using the proposed method. Accordingly, a selective and organized liner thickness design can be developed.

TELM에 적용한 직병렬 공진형 DC/DC 컨버터의 출력전압 제어에 관한 연구

황계호,이영식,전진용,방덕제,김호종,신병철,강도현,김종무,Hwang Gye Ho,Lee Young Sik,Jeon Jin Yong,Bang Deok Je,Kim Ho Jong,Shin Byoung Chol,Kang Do Hyun,Kim Jong Moo 한국반도체디스플레이기술학회 2005 반도체디스플레이기술학회지 Vol.4 No.1

In this paper, with loosely coupled transformer Relies-parallel resonant type DC/DC converter is analyzed and adopted to the power source of a TFLM(Transverse Flux Linear Motor). To get more efficient operating mode of the series-parallel resonant type DC/DC converter, theoretical analysis using normalized parameters are accepted. The analysis includes a specially made ferrite transformer with two separately wound half cores in order to evaluate analytically and experimentally the changes in magnetizing the leakage fluxes and inductances caused by the distance between the halves. The proposed converter must be operated in switching Pattern III among the three switching patterns for the Zero Voltage Switching operation. According to Pulse Frequency Modulation(PFM) control method, the output voltage of the proposed circuit can be controlled. The results of the theoretical development are compared with practical measurements from a prototype system.

자궁근종과 성호르몬 대사물과의 연관성

배상욱,정병화,정봉철,전진동,이현정,권한성,정경아,김세광,박기현,Bai, Sang-Wook,Jung, Byung-Hwa,Chung, Bong-Chul,Jeon, Jin-Dong,Lee, Hyun-Jung,Kwon, Han-Sung,Chung, Kyung-Ah,Kim, Sei-Kwang,Park, Ki-Hyun 대한생식의학회 2001 Clinical and Experimental Reproductive Medicine Vol.28 No.4

Objective: To elucidate 1) whether there are any differences in the urine concentrations of steroid hormone metabolites between patients with leiomyoma and normal controls 2) the correlation between urinary profiles of steroid hormones and leiomyomas of the uterus according to their type, location, volume, and weight. Materials of Methods : The study population consisted of 37 premenopausal patients with uterine leiomyoma and the control group consisted of 25 premenopausal normal volunteer women without uterine leiomyoma. Confirmation of the existence of uterine leiomyoma was done by ultrasonography and histopathological examination after surgery. The volume of the leiomyoma was estimated by trans-abdominal and/or trans-vaginal ultrasonography. The Leiomyomas were divided into 3 types (subserosal, intramural and submucosal). Seventeen patients had subserosal type of leiomyoma, 10 with the intramural type and 10 with the submucosal type. The locations of the leiomyoma were also divided into 3 groups (fundus, body and isthmus). Seventeen patients showed a fundus location, 10 in body, and 10 in isthmus. We compared urinary profiles of the endogenous steroids between patients with leiomyomas and normal controls, and also investigated the relationship between urinary profiles of the endogenous steroids and leiomyomas according to their type, location, volume and weight by using highly sensitive Gas Chromatography-Mass Spectrometry (GC-MS) system. Results: The mean ages of the patients with leiomyomas and the control group were $43.1{\pm}5.6$ and $40.6{\pm}7.2$ years, the weights were $63.4{\pm}7.3$ and $59.4{\pm}8.1\;kg$, and their heights were $155.4{\pm}4.8$ and $159.3{\pm}4.8\;cm$ respectively. Seventeen patients had subserosal, 10 had intramural, and 10 had submucosal leiomyomas. There were 17 patients with leiomyoma located in fundus, 10 in body and 10 in isthmus. $17{\beta}$-estradiol, 5-AT, 11-keto ET, $11{\beta}$-hydroxy An, $11{\beta}$-hydroxy Et, THS, THA, THE, a-cortolone, a-cortol, $\beta$-cortol, $11{\beta}$-OH Et/$11{\beta}$-OH An and E2/E1 were significantly increased in patients with leiomyoma than in the control group. $17{\beta}$-estradiol was significantly increased in the intramural and the submucosal types than in the subserosal type. There was no significant difference in the concentrations of urinary steroids according to the locations of leiomyomas. There was no significant relationship between the concentration of urinary steroids and the volume of the leiomyomas. $17{\beta}$-estradiol significantly decreased as the weight of uterus increased (r=-0.322, p=0.04). Conclusion: The concentrations of steroid hormone metabolites were generally increased in patients with leiomyoma but were not significantly related to the volume and weight of the leiomyomas. Our study suggests that steroid hormones may be involved in the initiation of leiomyomas but may not be involved in their progression. In addition, the concentrations of steroid hormone metabolites are not related to the leiomyoma type and location.

HexaSlide 형 병렬로봇의 적응제어

김종필,김성관,전진철,이선규,류제하 제어로봇시스템학회 1999 제어로봇시스템학회 국내학술대회 논문집 Vol.4 No.10

유연성 선형 성형작약 개발에 관한 연구

박병찬,장일호,이우진,전진철,Park, Byung-Chan,Chang, Il-Ho,Lee, Woo-Jin,Jeon, Jin-Cheol 한국군사과학기술학회 2009 한국군사과학기술학회지 Vol.12 No.3

The shaped charge consists of the cast or pressed explosive and the metal liner. The pressure formed in detonation wave is so high that the liner is collapsed and the jet of high temperature, pressure and velocity is produced. The jet penetrates the target. In this paper, the simulation for optimization of flexible linear shaped charge(FLSC) was carried out by AUTODYNE program. Based on the results of simulation, we made a prototype of FLSC and evaluated penetration performance, flexibility and its application. The test result of prototype was compared with that of simulation.

Profiling of Differentially Expressed Genes in Human Stem Cells by cDNA Microarray

김철근,이종주,정대영,전진선,허현석,강호철,신준호,조윤신,차경준,김찬길,도병록,김경숙,김현수 한국분자세포생물학회 2006 Molecules and cells Vol.21 No.3

Stem cells are unique cell populations with the ability to undergo both self-renewal and differentiation, although a wide variety of adult stem cells as well as embryonic stem cells have been identified and stem cell plasticity has recently been reported. To identify genes implicated in the control of the stem cell state as well as the characteristics of each stem cell line, we analyzed the expression profiles of genes in human embryonic, hematopoietic (CD34+ and CD133+), and mesenchymal stem cells using cDNA microarrays, and identified genes that were differentially expressed in specific stem cell populations. In particular we were able to identify potential hESC signature-like genes that encode transcription factors (TFAP2C and MYCN), an RNA binding protein (IMP-3), and a functionally uncharacterized protein (MAGEA4). The overlapping sets of 22 up-regulated and 141 downregulated genes identified in this study of three human stem cell types may also provide insight into the developmental mechanisms common to all human stem cells. Furthermore, our comprehensive analyses of gene expression profiles in various adult stem cells may help to identify the genetic pathways involved in self-renewal as well as in multi-lineage specific differentiation.