전단보강근이 없는 강섬유 보강 합성보의 휨 거동에 대한 실험연구

남영길(Nam Young-Gil),최종식(Choi Jong-Sik),김정해(Kim Jeong-Hae),오영훈(Oh Young-Hun),안병익(Ahn Byung-Ik) 한국구조물진단유지관리학회 2006 한국구조물진단학회 학술발표회논문집 Vol.10 No.1

Recently, it is interested in composit and hybrid structural systems because these could make the effective structural members and systems through the reasonable combination of structural materials. The objective of this study is to investigate the flexure and shear strength of composite beam using steel fiber concrete and angle. For this purpose, five composite beams are constructed and tested. Based on the results, both steel fiber and angle can increase the strength. Howevre, ductile behavior could be feasible for adequate tensile reinforcement ratio. Therefore, it is considered that the composite beam system could achieve the desirable behavior with ductile manner.

동양평화론과 조선인의 인식 -안중근의 국제정세 인식을 중심으로-

최종길 ( Jong-gil Choi ) 수선사학회 2016 史林 Vol.0 No.55

Ahn is considered to be in the fact that Russia, which has been contemplated the cause imperialistic expansion at East Asia of the Russo-Japanese war has enhanced the military force in order to ensure the ice-free port. And he will be helpful and laid the cornerstone for the Oriental peace dismissed the Russian China-Japan-Korea with a focus on Japan in the Russo-Japanese War is united. The original purpose of the day Russia war Ahn to grasp is to restrain Russia to spread the forces in Asia, through which was to guarantee the independence of Korea. As a result, it was something oriental peace can be maintained. However, Japan will not be able to receive war reparations, Hirobumi Ito, contrary to the Government of Japan and the Emperor of intent, Ahn that it has taken the Korea discards the original purpose of the Russo-Japanese War to judge. In other words, Ahn is the Japanese government is not particularly than Emperor broke the promise at the time the Russo-Japanese War war, believe Hirobumi Ito broke the promise. Ahn criticism awareness of Enlightenment Party that could not be the success of the reform was very weak. Such recognition, appeared in fact recognized the reality lack is the correlation of the international situation in conjunction with the background of the occurrence of Donghak with this. As a result, Ahn was not able to fully recognize the complex and ruthless international political situation in which mingled the ought and reality.

국가총동원법의 실시와 휘발유 배급통제 실태-1939년 조선총독부 법무국 사례를 중심으로-

최종길(Choi, Jong-Gil) 한일관계사학회 2021 한일관계사연구 Vol.72 No.-

국가총동원법 실시 이후 1939년 4월 24일 확정된 「물자통제의 대강」에 의하면, 1939년도 관청수요는 50% 절감이었다. 한편 1939년 7월에 관청용 휘발유 소비절약에 관한 협의회에 제출된 안건에 의하면, 1939년도 조선의 휘발유 할당량은 전년도에 비하여 28% 삭감이었다. 이러한 감축 때문에 휘발유의 소비절감을 위하여 9, 10월분부터 할당제가 실시되었다. 이어서 조선총독부는 각 법원이 보유하고 있는 승용차 1대당 휘발유의 1일 할당량을 2.7리터로 고정하였으며, 법원의 등급과 교통상황에 따라 휘발유의 할당량을 증감하였다. 그 결과 조선총독부는 승용차 한 대당 할당된 평균치 보다 적은 량의 휘발유를 각 법원에 배급하였다. 1939년의 이러한 배급통제 방식은 석유수급 상황에 따라 조금은 유동적이었다. According to the “Summary of Material Control” confirmed on April 24, 1939 after the implementation of the Total National Mobilization Act, the demand for government offices in 1939 was reduced by 50%. On the other hand, according to the agenda submitted to the Council on the Consumption of Gasoline for Government Offices in July 1939, Joseon’s gasoline quota in 1939 was cut by 28% compared to the previous year. Due to these reductions, the quota system was implemented from September and October to reduce gasoline consumption. Subsequently, the Governor-General of Joseon fixed the daily quota of gasoline per passenger car held by each court at 2.7 liters, and increased or decreased the gasoline quota according to the court"s grade and traffic conditions. As a result, the Governor-General of Joseon distributed less gasoline to each court than the average allotted per car. This distribution control method in 1939 was somewhat flexible depending on the oil supply and demand situation.

비정규 분포의 잡음인자를 고려한 곱분해기법 기반의 통계 모멘트를 이용한 효율적인 강건 최적설계

조수길(Su-gil Cho),이민욱(Minuk Lee),임우철(Woochul Lim),최종수(Jong-Su Choi),김형우(Hyung Woo Kim),홍섭(Sup Hong),이태희(Tae Hee Lee) 대한기계학회 2012 大韓機械學會論文集A Vol.36 No.11

제품의 성능은 시스템에 작용하는 환경인자, 재료 물성치와 같은 잡음인자의 변동에 큰 영향을 받는다. 제품의 성능을 위해서, 이러한 잡음인자의 변동에 따른 영향을 줄이는 것이 필요한데 이를 강건설계라 한다. 하지만 기존의 강건설계는 잡음인자의 변동이 아닌 설계변수의 변동을 중요하게 생각했다. 또한 변수와 인자의 분포를 정규분포로 가정해야 하는데 이는 실제 잡음인자의 분포와 맞지 않는 경우가 많다. 본 논문에서는 비 정규분포의 잡음인자의 분포를 고려하는 강건최적설계 기법을 제안한다. 제안된 기법은 실험을 통해 추정된 잡음인자의 비 정규분포 변동을 고려할 수 있다. 제안된 기법의 유용성을 확인하기 위해 공학예제로 심해저 망간 채집장치의 강건설계를 수행하였다. The performance of a system can be affected by the variance of noise factors, which arise owing to uncertainties of the material properties and environmental factors acting on the system. For robust design optimization of the system performance, it is necessary to minimize the effect of the variance of the noise factors that are impossible to control. However, present robust design techniques consider the variation of design factors, and not the noise factors, as being important. Furthermore, it is necessary to assume a normal distribution; however, a normal distribution is often not suitable to estimate the variations. In this study, a robust design technique is proposed to consider the variation of noise factors that are estimated as non-normal distributions in a real experiment. As an example of an engineering problem, a deep-sea manganese nodule miner tracked vehicle is used to demonstrate the feasibility of the proposed method.

강섬유 보강 콘크리트의 휨강도 및 휨인성 특성에 관한 연구

최종식 ( Choi Jong-sik ),남영길 ( Nam Young-gil ),김정해 ( Kim Jeong-hae ),오영훈 ( Oh Young-hun ),안병익 ( Ahn Byung-ik ) 한국구조물진단유지관리공학회 2006 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.10 No.1

The purpose of this study is to investigate the mechanical properties of flexural strength and toughness index of concrete with steel fiber. For this purpose, total 42 specimens which have some variables such as two level of concrete compressive strength; 30MPa, 50MPa, and two aspect ratio; 62, 72, and volume contents of steel fiber; 0%, 1%, 1.5%, 2%, 3%. From the result of experimental test, flexural strength and toughness index of steel fiber concrete are much enhanced with respect to the fiber volume content and the aspect ratio.

Nifedipine이 인체 치은섬유모세포의 세포활성에 미치는 효과

최종길,김재현,신형식,Choi, Jong-Gil,Kim, Jai-Hun,Shin, Hyung-Shik 대한치주과학회 1993 Journal of Periodontal & Implant Science Vol.23 No.3

Gingiva is remarkly sensitive to certain drugs. Especially, long term use of phentoin, dihydropyrydine (including nifedipine), cyclosporin and other drugs can be lead to pathologic changes in gingival tissue, especially in terms of proliferation of epithelium and connective tissue. Recent study in terms of proliferation of epithelium and connective tissue. Recent study is focused on the inhibition of drug-induced gingival hyperplasia by using medicaments. The purpose of this study was to investigate on the pharmacological effects of nifedipine, retinoic acid and glycyrrhetini acid to the activity in human gingival fibroblast. Human gingival fibroblasts were cultured from the healthy gingiva of orthodontic patients. Gingival fibroblasts were trypsinized and cultured in growth medium added $5{\mu}g/ml$ of nifedipine, $10^{+7}M$ of retinoic acid and glycyrrhetinic acid. The passage number of cultured fibroblasts were between fifth and eighth. The cell morphology was examined by inverted microscope and the cell acitivity was measured by the MTT assay. Nifedipine at the concentration of $5{\mu}g/ml$ was revealed significantly effective to increase the cell activity and lipopolysaccharide was cofactor to increase cell activity in the presence of nifedipine. However, retinoic acid was significantly effective on the globular change of cell morphology and loss of cell process regardless of the presence of nifedipine and LPS. Cell activity was significantly decreased by the glycyrrhetinic acid at the concentration of $10^-M$ regardless of the presence of nifedipine and LPS. These results suggested that the increased cell activity by nifedipine might be modulated by retinoic acid and glycyrrhetinic acid. Further study is needed to clarify on their toxicological effects during cellular modulation and mRNA expression change.

철도차량 보조전원장치의 전압 제어 안정성 증대를 위한 Anti-windup 기법의 적용 및 비교 분석

최종용(Jong-Yong Choi),이수길(Su-Gil Lee),이준희(June-Hee Lee),이현재(Hyun-Jae Lee),손진근(Jin-Geun Shon) 대한전기학회 2021 전기학회논문지 P Vol.70 No.4

In this paper, Application and Comparative Analysis of Anti-windup Method for Improving the Stability of Voltage Control of Auxiliary Power Supplies in Railway System. Because it is easy to design, and the structure is simple, there is a problem in the widely used PI controller to occur. Various problems occur, such as response time delay and overshoot due to integrator windup caused by the accumulation of errors in the integral controller. To improve this, various anti-windup methods have been studied. Among the representative Anti-windup methods, it was checked whether various problems caused by integrator windup could be solved through the conditional integral Anti-windup method and the tracking Anti-windup method and the error control Anti-windup. After confirming through PSIM simulation before hardware experiment, DC power conversion system was designed and improvements were confirmed.

심해 잡음인자를 고려한 망간단괴 시험집광기의 채집운용시 주행장치 다구치 강건설계

조수길(Su-gil Cho),이민욱(Minuk Lee),임우철(Woochul Lim),최종수(Jong-Su Choi),김형우(Hyung-Woo Kim),이창호(Chang-Ho Lee),홍섭(Sup Hong),이태희(Tae Hee Lee) 한국해양공학회 2012 韓國海洋工學會誌 Vol.26 No.1

A deep-sea manganese nodule miner consists of 4 parts: the pickup device, crusher, disposal device, and tracked vehicle. The tracked vehicle is an essential component to keep the self-propelled miner moving across deep-sea soil. The performances of the tracked vehicle are influenced by noise factors: the shear strength of the seafloor, bottom current, seafloor slope, track speed, reaction forces of flexible hose, etc. It is necessary to adopt a robust design method that improves the performances and minimizes the variation caused by noise factors. Taguchi’s method, the most widely known robust design method, searches for the robust optimum using an orthogonal array composed of the product of the inner array and outer array. In this paper, we propose a new screening technique to reduce the number of input factors and apply the MRSN (Multi-Response Signal to Noise) ratio to convert multiple performances into single one in order to overcome the difficulties and limitations of using Taguchi’s method in a case with many input factors and multiple performances. A test miner was already designed and tested. It has about 1/10 the capacity of a commercial one and was successfully operated at an in-shore area. Taguchi’s robust design was applied to the tracked vehicle of the test miner, and design improvements were implemented for the vehicle.

대동아전쟁과 다케우치 요시미(竹內好)의 전쟁책임론

최종길 ( Jong-gil Choi ) 수선사학회 2018 史林 Vol.0 No.64

This paper examines how Takeuchi changed his attitude towards war responsibility and problems in the Great War after his defeat. Takeuchi thought that he could transform the outside world through self-denial and self-innovation instead of external authority. He concluded that this idea coincided with the Great East Asian War, which criticized the Western modernity on December 8, 1941, declaring propaganda against the United States and called for the establishment of the Greater East Asia Coalition through the transformation of the Japanese nation. And he positively accepted this war. After the defeat, Takeuchi discussed the issue of war responsibility, saying that Japan's war was an invasion war as well as an imperialist war. Takeuchi argued that he could not agree to transfer responsibility for the imperialist war to Japan alone. Therefore, Takeuchi's war responsibilities were not limited to war responsibility for everything, but rather limited to which part of war and which side to take responsibility for. It seems that Takeuchi does not deny the meaning of the War of Great East Asia in the same way as before. Based on this perception, he traced the problems of Japanese modernization. In order to achieve this purpose, he changed the method of studying only China and included the problem of Japanese modernization in the postwar period.

전단보강근이 없는 강섬유 보강 합성보의 휨 거동에 대한 실험연구

남영길 ( Nam Young-gil ),최종식 ( Choi Jong-sik ),김정해 ( Kim Jeong-hae ),오영훈 ( Oh Young-hun ),안병익 ( Ahn Byung-ik ) 한국구조물진단유지관리공학회 2006 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.10 No.1

Recently, it is interested in composit and hybrid structural systems because these could make the effective structural members and systems through the reasonable combination of structural materials. The objective of this study is to investigate the flexure and shear strength of composite beam using steel fiber concrete and angle. For this purpose, five composite beams are constructed and tested. Based on the results, both steel fiber and angle can increase the strength. However, ductile behavior could be feasible for adequate tensile reinforcement ratio. Therefore, it is considered that the composite beam system could achieve the desirable behavior with ductile manner.