용탕단조법에 의한 AC8A / Al2O3 복합재료의 기계적 성질에 관한 연구

김기배,김경민,조순형,윤의박 ( Ki Bae Kim,Kyoung Min Kim,Soon Hyung Cho,Eui Park Yoon ) 한국주조공학회 1991 한국주조공학회지 Vol.11 No.6

N/A In this study the fabrication technology and mechanical properties of AC8A/Al₂O₃ Composites by squeeze casting process were investigated to develope for application as the piston materials that require good friction, wear resistance, and thermal stability. AC8A/Al₂O₃ composistes without a porosity and the break of preform were fabricated at the melt temperature of 740℃, the preform temperature of 500℃, and mold temperature of 400℃ under the applied pressure of 1200㎏/㎠ as the results of the observation of microstructures. As the results of this study, the tensile strength of AC8A /Al₂O₃composites was not increased linearly with Al₂O₃volume fraction and so it seemed not to agree with the rule of mixture, which had been used often in metal matrix composite. Also the tensile strength after thermal fatigue test was little different from that before the test. Consequently it was thought that AC8A /Al₂O₃composites fabricated under our experimental conditions had a good thermal stability and subsequently a good interface bonding. Wear rate(i.e., volume loss per unit sliding distance) of AC8A/Al₂O₃composites was decreased with Al₂O₃volume fraction and the sliding speed at both room temperature and 250℃ and so there was a good correlation between wear rate and hardness. Also the wear rate of AC /8A20% Al₂O₃composities was obtained the value of 1.65 ㎤/㎝ at sliding speed of 1.14m/sec as compared with about 3.0×10^(-8)㎤/㎝hyereutectie Al-Si alloy(Al-16%Si-2%Cu-1%Fe-1%Ni), which applied presently for piston materials. The wear behavior of Al₂O₃composites was observed to a type of abrasive wear by the SEM view of wear surface.

반응고가공용 소재제조기술

김기배,윤의박 ( Ki Bae Kim,Eui Pak Yoon ) 대한금속재료학회 1997 大韓金屬學會會報 Vol.10 No.2

스퀴즈캐스팅용 Salt Core 의 제조 및 용탕침투성에 관한 연구

김기배,노상우,이호인,남태운 ( Ki Bae Kim,Sang Woo Noh,Ho In Lee,Tae Woon Nam ) 한국주조공학회 1997 한국주조공학회지 Vol.17 No.4

N/A Developing a salt core for squeeze casting process, two different salt cores(pure salt core and mixed salt core) were fabricated and investigated. Pure salt core was composed of 100% NaCl and mixed salt core was made by mixtures of NaCl with MgO(1%), Na₂B₄O_7(2%), and talc(1%) as a binder or a strengthening agent. Salt cores were compacted to various theoretical density, heat treated, and then squeeze-cast with molten Al alloy(AC8A). The compression strength of salt cores were measured and the squeeze-cast products were examined for shape retention, infiltration of molten metal into the cores, and microstructures. The shape of salt core compacted at above 75% of the theoretical density was maintained stably. The higher theoretical density of salt cores gave higher compression strength, and the compression strength of mixed salt core was higher than that of pure salt core. Namely at 90% theoretical density, the compression strength of mixed salt core was 6.3㎏/㎟, compared to 4.6㎏/㎟` for pure salt core. At a squeeze casting pressure of 1000㎏/㎠, molten Al alloy was infiltrated into pure salt core of under 85% of the theoretical density. At squeeze casting pressure of 1000㎏/㎠, only mixed salt core above 90% of the theoretical density were valid, but the shape of the core was altered in the case of pure salt core at 90% of theoretical density. A key factor for developing a salt core for squeeze casting process was estimated as the ultimate compressive strength of salt core.

Al-Li / SiC 계면의 젖음성에 관한 연구

김기배,김도향,이호인 ( Ki Bae Kim,Do Hyang Kim,Ho In Lee ) 한국주조공학회 1992 한국주조공학회지 Vol.12 No.2

N/A The wetting behaviour of SiC /Al-Li composite interface has been investigated by using an infiltration method. The critical pressure for melt infiltration into SiC particulate preform has been determined by measuring the melt infiltration distance changes with the variation of applied pressure. The threshold pressure of pure Al, Al-0.2wt%Li, Al-0.5wt%Li for melt infiltration are 3.94, 3.93> 3.75㎏/㎠ respectively, which implies a slight improvement in wettability of SiC /Al composite by addition of Li. The threshold pressure for melt infiltration also changes with the variation of other parameters such SiC particulate size, SiC particulate fraction and melt temperature.

사상체질처방과 훈증요법을 병행한 여드름 치험 6례

김기배,김태욱,최성희,Kim, Ki-Bae,Kim, Tae-Wook,Choi, Sung-Hee 대한한방안이비인후피부과학회 2016 한방안이비인후피부과학회지 Vol.29 No.2

Objectives : This study was to performed to investigate the effect of herbal steam therapy on acne vulgaris. Methods : 6 patients with acne vulgaris were treated with korean medicine therapy (herbal medicine and acupunture) including herbal steam therapy. We evaluated the effect by Korean Acne Grading System(KAGS) and Pictures. Results : After treatment, the KAGS Grade of all patients treated with korean medicine therapy including herbal steam therapy is 1. Based on this, we could find that korean medicine therapy including herbal steam therapy is effective and available to ameliorate for the symptoms of acne vulgaris. Conclusions : This clinical cases study shows us that korean medicine therapy including herbal steam therapy seem to be effective to improve symptoms of acne vulgaris. Further studies will be needed to identify herbal steam therapy is beneficial to acne vulgaris.

한방치료를 통한 백반증 치험 4례

김기배,김태욱,Kim, Ki-Bae,Kim, Tae-Wook 대한한방안이비인후피부과학회 2015 한방안이비인후피부과학회지 Vol.28 No.1

Objectives : The purpose of this study was to investigate the clinical efficacy of treatment of vitiligo patients in Korean Medicine Treatment. Methods : This case study was done on four vitiligo patients who had visited Korean Medicine Clinic. All the patients are treated with herbal medication and acupuncture treatment. Photographs were used to evaluate the symptom change. Results : Four vitiligo patients who were treated by Korean Medicine Treatment (herbal medication and acupuncture) showed efficient clinical results. Conclusion : Most symptoms of patients were improved in this study. Herbal medication and acupuncture treatment can be effective in patients who were diagnosed as Vitiligo.

고순도알루미늄정제시 유동이 불순물분포에 미치는 영향

김기배,김경민,이재철,이호인,윤의박,조남돈 ( Ki Bae Kim,Kyoung Min Kim,Jae Chul Lee,Ho In Lee,Eui Pak Yoon,Nam Don Cho ) 한국주조공학회 1996 한국주조공학회지 Vol.16 No.3

N/A The effect of forced convection on the solute redistribution of the Al ingot is studied in an effort to fabricate high purity aluminum using a fractional solidification processing. Experimental setup is built in order for the Al melt to be solidified from the surface of the graphite cooling tube, which is rotated at a constant revolution rate to generate the forced convection environmental ahead of the solidification front. Based on the experimental results, Fe and Si concentrations, added as impurities within the Al ingot, decrease as the distance measured from the graphite tube and growth rate decreases and as revolution speed increases. In the case of Al melt with high initial solute concentration, spiral columnar grains tend to form along a direction of revolution. In the case of Al melt with low solute concentrations, however, grains tend to grow with planar geometry. In the fractional solidification process, the solute concentration within the solid phase tends to decrease at the early stage of solidification, reaches minimum concentration, and then increases gradually as solidification proceeds. The solute redistribution obtained based on the BPS model incorporated with the tangential flow component as well as the axial flow component within the melt, agree well with the measurements under sufficiently high revolution speed and low solidification rate.

발효된 연교금은화 추출물 외치액을 병행한 지루성 피부염 치험 4례

김기배,김태욱,최성희,Kim, Ki-Bae,Kim, Tae-Wook,Choi, Sung-Hee 대한한방안이비인후피부과학회 2013 한방안이비인후피부과학회지 Vol.26 No.4

Objectives : The purpose of this study is to report the effect of Fermented Yungyo Keumeunhwa Extract External treatment Liquid on Seborrheic Dermatitis. Methods : Four Seborrheic Dermatitis patients on the face of each Diluted Yungyo Keumeunhwa Extract External treatment Liquid patch was 10 minutes. Results : The Fermented Yungyo Keumeunhwa Extract External treatment Liquid was effective on alleviation of symptoms like flare, scale, uredo and pricking on Seborrheic Dermatitis. Conclusions : The result indicate that Fermented Yungyo Keumeunhwa Extract External treatment Liquid has an available effect on Seborrheic Dermatitis, and authors consider that the additional clinical studies are needed to verify the effectiveness of monotherapy.

전자기교반에 의한 연속주조빌렛트제조

김기배(Ki-Bae Kim) 한국소성가공학회 1999 압출 및 인발 심포지엄 Vol.1999 No.5

TV 프로그램에 대한 투입과 성과 간의 관계 연구

김기배(Ki-Bae Kim),권호영(Ho-Young Kwon) 한국언론학회 2005 한국언론학보 Vol.49 No.6

This study is to examine the effect of input factors of 1V program on market performance, which depends on an economic profit and a rating. This study also offers a realistic viewpoint about the international flow of 1V programs by analyzing market results not only in the home market but also in the international market. The following is the research questions: first, what kind of relationship do input factors of the Korean terrestrial programs and program marketability have?; second, what is the most important input factor of the Korean terrestrial programs that affect the program marketability? This dissertation examines the market performance of terrestrial programs broadcasted by a certain Korean network for three years, from 2001 to 2003. Consequently, 404 programs are analyzed in total. The first research question investigates the correlations between input factors and market performances. The second research question utilizes a multiple regression analysis. Several important conclusions can be drawn from the outcomes of this study. First, time programing affects network ratings performance and ad income. Second, ratings affect a domestic program sales income. The multiple regression analysis indicates that time programing affects ratings performance more than production cost or genre. Time programing is also the most important factor in determining ad income. In addition, time programing is the most important factor for a domestic program sales income, compared with drama genre, which is the most important factor for an abroad program sales income. This study has a significance because it tries to verify accomplishments of the domestic terrestrial TV programs. In the reality of Korean society, it is natural that time programing is the most important factor for network ratings and ad income. Therefore, this study suggests that terrestrial broadcasters have a strategy that they, first of all, produce solid programs with sufficient production cost, and then determine time programing. In addition, genre factors are important for the explanation of program exports. More concerns about and investment in the Asian market are necessary, referring to the Korean Wave, which is currently sweeping across Asia. The analysis of the abroad sales income by countries indicates some phenomena which have a possibility to be a problem. Both SBS and MBC focus only on a part of the Asian countries. Also, dramas cover almost 90 percents of the import genres, which is a result of the Korean Wave suddenly swept since 2000. The Korean terrestrial broadcasters need to be interested in various genres except dramas to expand the international market in the future. In addition to development of various genres, such as cultural programs and artistic programs, improvement of the program quality should be promoted. In consequence, this study can help terrestrial broadcasters strengthen their competitiveness and improve efficiency of program production in essence. The government is recently promoting introduction of the new terrestrial channels, which leads the terrestrial TV program market to improve in its quantity and quality. This study will go far toward preparing for change in the market organization, referring to the market improvement.