구리를 함유하지 않은 친환경 자동차 브레이크 패드의 마모 특성에 관한 연구

김기봉,양상선,이성주,황석훈,김신욱,김용진,Kim, Ki-Bong,Yang, Sangsun,Lee, Seong-Ju,Hwang, Suk-Hun,Kim, Sin-Wook,Kim, Yong-Jin 한국분말야금학회 2018 한국분말재료학회지 (KPMI) Vol.25 No.1

The friction characteristics of Al-Fe alloy powders are investigated in order to develop an eco-friendly friction material to replace Cu fiber, a constituent of brake-pad friction materials. Irregularly shaped Al-Fe alloy powders, prepared by gas atomization, are more uniformly dispersed than conventional Cu fiber on the brake pad matrix. The wear rate of the friction material using Al-8Fe alloy powder is lower than that of the Cu fiber material. The change in friction coefficient according to the friction lap times is 7.2% for the Cu fiber, but within 3.8% for the Al-Fe alloy material, which also shows excellent judder characteristics. The Al-Fe alloy powders are uniformly distributed in the brake pad matrix and oxide films of Al and Fe are homogeneously formed at the friction interface between the disc and pad, thus exhibiting excellent friction and lubrication characteristics. The brake pad containing Al-Fe powders avoids contamination by Cu dust, which is generated during braking, by replacing the Cu fiber while maintaining the friction and lubrication performance.

지반가속도의 시뮬레이션과 강기반상(剛基盤上)에 설치된 회전측-베어링계의 지진해석

김기봉,Kim, Ki Bong 대한토목학회 1989 대한토목학회논문집 Vol.9 No.4

비선형 거동을 일으키는 구조물의 불규칙 진동해석이나 운동방정식이 매개여기와 비제차 여기를 포함하는 능동장비의 동적해석에는 불규칙 진동분야에서 보편적으로 사용되는 스펙트럼해법의 적용이 불가능하다. 만약 불규칙 입력하중을 인공적으로 시뮬레이션 할 수 있다면 이러한 문제들은 운동방정식에 직접적분법을 적용하여 동적응답을 얻을 수 있다. 본 논문에서는 FFT기법을 이용하여 비정상 불규칙 지반가속도를 시뮬레이션하는 효과적이고 실제적인 방법을 제시하며, 이렇게 얻은 인공지진을 응용하는 문제로서 지진하충을 받는 회전축-베어링계의 동적응답을 시뮬레이션하였다. 또한 시뮬레이션기법의 적용성 및 실용성을 검토하기 위한 민감도에 대한 연구도 제시하였다. The classical spectral analysis of random vibration is not applicable to the random vibration of nonlinear structures or the dynamic response of active mechanical systems whose governing equations contain random parametric and inhomogeneous excitations. If the random load is simulated, dynamic responses can be obtained with the application of numerical integration schemes to the governing equations of above problems. Thus, in this paper, efficient and practical methods of simulating nonstationary random seismic ground accelerations are presented by using the fast Fourier transform technique. Typical applications of the simulated ground accelerations are the simulations of the dynamic response of rotor-bearing systems under earthquake excitations. The study of accuracy is presented to determine the applicability and practicality of methods of simulation.

프로모터 영역의 전사인자 결합부위 Consensus 패턴 탐색 방법

김기봉,Kim, Gi-Bong 한국유전체학회 2007 유전체소식 Vol.7 No.4

총폐정맥 이상환류증의 수술요

김기봉,노준량,Kim, Gi-Bong,No, Jun-Ryang 대한흉부심장혈관외과학회 1984 Journal of Chest Surgery (J Chest Surg) Vol.17 No.1

Total anomalous pulmonary venous connection [TAPVC] defines a group of congenital heart disease which have in common the entire pulmonary venous drainage returning directly or indirectly to the right atrium instead of to the left atrium. Although this disorder represents only 1.3% of cases of congenital heart disease, if untreated the resultant mortality is greater than 80% in the 1st year of life. And since there is no satisfactory palliative treatment, correction of TAPVC Is high on the list of indications for open heart surgery in the 1st year of life. This paper describes 10 patients who underwent surgical correction of this disorder at SNUH between 1978 and 1983. 1. 7 were males and 3 females, with ages ranging from 5 months to 24 years. 2. 7 were supracardiac type, 2 cardiac type, and 1 mixed type TAPVC. We didnt experience infracardiac type. 3. All showed some degree of pulmonary hypertension preoperatively. 4. In 4 cases of supracardiac type, total circulatory arrest was used in brief period during anastomosis between common pulmonary venous trunk and left atrium. In the other cases, usual cardiopulmonary bypass with moderate to deep hyperthermia was used. 5. There were 2 cases of mortality; 1 died at operation, and the other at 4 months due to congestive heart failure. 6. Mortality seemed not closely related to age, body weight, or severity of pulmonary hypertension.

Fe-Cr-Mo 합금 분말의 성형 및 소결특성에 미치는 입도분포 영향

김기봉,양상선,김용진,박용호,Kim, Ki-Bong,Yang, Sangsun,Kim, Yong-Jin,Park, Yong-Ho 한국분말야금학회 2013 한국분말재료학회지 (KPMI) Vol.20 No.1

The effect of particle size distribution on green and sintered properties of Fe-Cr-Mo prealloy powder was investigated in this study. For the study, prealloyed Fe-Cr-Mo powders with different particle sizes were mixed as various ratios and cold compacted at various pressure and sintered at $1250^{\circ}C$ for 30 min, $90%N_2+10%H_2$ atmosphere in the continuous sintering furnace. The results shows that the powders with large particle size distribution have high compressibility and low ejection force. However the green strength are much less than those with small particle size distribution. Tensile prperties of the sintered specimes with large particles size also have high strength and elongation.

종합서평 - "나는 왜 역사가가 되었나" "미시사와 거시사"

김기봉,Kim, Gi-Bong 대한출판문화협회 2001 출판저널 Vol.312 No.-

소아(小兒) stress에 관한 문헌적(文獻的) 고찰(考察)

김기봉,김장현,Kim, Ki-Bong,Kim, Jang-Hyun 대한한방소아과학회 2002 대한한방소아과학회지 Vol.16 No.1

With the progress of civilization, the disorders due to the stress, which derived from the social-structural complexity and diversity, are on an increasing trend in our times. Accordingly, the accurate diagnosis and appropriate treatment for them are required. Especially in the current years, children's disorders delivered by the emotional problems keep increasing. In this research, the researcher tried to figure out the cause of the children's stress and its treatment, studied the theories of the stress in the modem medicine and the sever emotions in oriental medicine, and came to the conclusion as follows: 1. The stress can be defined as the combination of the reaction to noxious stimuli and its defense mechanism of the body, In oriental medicine, it is considered as pathological notions which includes seven emotions as the internal factor, six evils as the external factor and other foods, expectoration, ecchymoma as the non-internal/external factors. 2. Children usually get stressed by various reasons in a growth process such as schooling, relationship with friends, the opposite sex of family, or change of surroundings, and these can cause the various disorders. 3. In the study of the children's stress symptoms, it is found that the silent reaction is uncommon. It usually appeared in both reactions: firs, physical reactions such as stomachache, vomiting, headache, neural frequent urination, bronchial asthma or excessive respiration and/or, second, behavioral reactions such as a decline of performance, alimentary disorder, e.g. anorexia nervosa or bulimia, sleep disorder, e.g. nightmare or panic in sleep, anthrophobia, refusal to a school attendance or hyperactiveness. Besides, the peculiar mental disorder such as paroxysm of anger, tic, autism, nocturnal enuresis, lack of attentiveness, impediment in linguistic development, learning difficulty, intellectual decline, etc. can be appeared, and the heavy stress during the babyhood can cause the regression of behavior or the immaturity of formation of character. 4. The appropriate treatments for the children's stress are Osteopathy, Manpulation, Aroma Therapy, Alexander Technique, Autonomic Never Control Treatment, Biofeedback, Chiropractic, Dance Therapy, Feldenkrasis Technique, Gravity Therapy, Homepathy, Aquatherapy, Hypnotherapy, Naturopathy and Meditation.

마황, 인삼, 택사 복합추출물의 endocannabinoid system 억제를 통한 비알콜성 지방간 유도 인슐린저항성 개선 효과

김기봉,안상현,Kim, Ki Bong,Ahn, Sang Hyun 대한한방소아과학회 2020 대한한방소아과학회지 Vol.34 No.4

Objectives This study aimed to investigate the efficacy of Ephedra sinica (E. sinica), Panax ginseng (P. ginseng), and Alisma orientale (A. orientale) Extract (MIT) on insulin resistance induced by Non-alcoholic fatty liver disease (NAFLD). Methods C57BL /6 male mice (8-week-old, 20 g) were divided into four groups: control group (Ctrl), high-fat diet group (HFDF), high fat diet with metformin administration group (METT), and high fat diet with MIT administration group (MITT). Each 10 mice were allocated to each group (a total of 40 mice). All mice were allowed to eat fat-rich diet freely throughout the experiment. To examine the effect of MIT, we observed Cannabinoid receptor type 1 (CB1), Cannabinoid receptor type 2 (CB2), G protein-coupled receptor 55 (GPR55), and Transforming growth factor-β (TGF-β). Results In the MITT group, positive reactions of the CB1, CB2, and GPR55 were significantly was significantly suppressed compared to the HFDF group. The positive reactions of the CD36 and TGF-β in the liver tissue were significantly suppressed in MITT. Conclusions MIT has the effect of improving NAFLD induced insulin resistance through the regulation of the lipid metabolism.

아토피피부염에서 갈근황금황련탕 추출물의 ECS 조절을 통한 염증 완화 효과

김기봉,안상현,Kim, Ki Bong,Ahn, Sang Hyun 대한한방소아과학회 2021 대한한방소아과학회지 Vol.35 No.4

Objective The purpose of this study was to confirm the effects of Galgeunhwanggeumhwangryeon-tang in reducing inflammation through the endocannabinoid system (ECS) control in atopic dermatitis. Methods 8-week-old Balb/C mice were divided into 4 groups: contorl group (Ctrl), lipid barrier elimination group (ADE), palmitoylethanolamide treated group after lipid barrier elimination (PEA), and Galgeunhwanggeumhwangryeon-tang applied group after lipid barrier elimination (GGRT). After inducing atopic dermatitis, cannabinoid receptor (CB) 1, CB2, CD68, phosphorylated inhibitor kappa B (p-IκB), inducible nitric oxide synthase (iNOS), substance P and serotonin were observed to confirm the regulation of the ECS, macrophage activity and mast cell activity. Results CB1 and CB2 showed higher positive reactions in the GGRT than in the LBE and PEA. CD68, p-IκB and iNOS showed higher positive reaction in the LBE, PEA and GGRT than in the Ctrl, but the increase in the positive reaction was lower in the GGRT compared to the LBE and PEA. Substance P and serotonin showed higher positive reaction in the LBE, PEA and GGRT than in the Ctrl, but the increase in the positive reaction was lower in the GGRT compared to the LBE and PEA. Conclusions The effects of Galgeunhwanggeumhwangryeon-tang were confirmed though the regulation of the ECS, macrophage activity and mast cell activity.

고폐동맥압을 동반한 선천성 심기형 환자에서 술후 폐동맥압과 혼합정맥혈 산소분압의 변화에 관한 분석

김기봉,김용진,Kim, Gi-Bong,Kim, Yong-Jin 대한흉부심장혈관외과학회 1989 The Korean Journal of Thoracic and Cardiovascular Vol.22 No.6

It has been suggested that mixed venous $O_{2}$ tension is a predicor of cardiac output especially in a critically ill patient after an open heart surgery. From April 1988 through September 1989, we monitored mixed venous $O_{2}$ tension and pulmonary arterial pressure in 48 patients with acyanotic congenital heart disease at postoperative 1 hour, 6 hour, 12 hour, 24 hour, and 48 hour respectively. They were divided into Group I, with severe pulmoary hypertension, and Group II, without severe pulmonary hypertension. In Group I, mixed venous $O_{2}$ tension and cardiac index showed significant increase with time (p<0.05), but the ratio of pulmonary-aortic systolic pressure didn't show significant change. The increase was significant only 24 hour after operation, and so this low cardiac performance in early postoperative period should be considered when postoperative management is being planned in the risky patient. In Group II, all of the three variables didn't show any significant change with time. The correlation coefficient between mixed venous $O_{2}$ tension and cardiac index was significantly different from zero in both Group I (p<0.001) and group II (p<0.05) at each imeperiod, but the ratio of pulmonary-aortic systolic pressure didn't correlated well with the other 2 variables. Our study showed that serial determination of mixed venous $O_{2}$ tension in acyanotic congenital heart disease could be used as a guide in estimating the cardiac index postoperatively.