Improvement of Thermoplastic Forming Ability of Ti–Zr–Ni–Cu Metallic Glass by Addition of Sn

Yeong‑Seong Kim,Woo‑Chul Kim,Won‑Tae Kim,Do‑Hyang Kim 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6

Ti–Zr–Ni–Cu metallic glass attracts an attention as a precursor of superelastic alloy that can be deformed into nm scalecomplex shapes. However, since the thermal stability of Ti–Zr–Ni–Cu metallic glass in the supercooled liquid region is quitelow, application of thermoplastic forming is limited. Therefore, in the present study, the effect of Sn addition on thermoplasticforming ability of Ti–Zr–Ni–Cu metallic glass has been investigated. Sn containing (Ti35Zr15Ni35Cu15)99Sn1 metallic glassexhibits longer incubation time before onset of crystallization than Ti35Zr15Ni35Cu15metallic glass, resulting in significantimprovement of thermoplastic forming ability. The crystallization behavior changes from three-dimensional growth of saturatednuclei to three-dimensional growth with constant nucleation rate with the addition of Sn. The overall activation energyfor crystallization of (Ti35Zr15Ni35Cu15)99Sn1 metallic glass is higher than that of Ti35Zr15Ni35Cu15metallic glass, indicatingthat the thermal stability of metallic glass is improved by addition of Sn. Because nuclei are continuously generated duringthe crystallization in (Ti35Zr15Ni35Cu15)99Sn1, the average grain size is much smaller than that in Ti35Zr15Ni35Cu15.

알루미늄 합금과 고장력 강판 접합을 위한 헬리컬 SPR의 단조공정 설계

김원영, 김동범, 김기호, 김도훈, 이인환, 조해용 충북대학교 산업과학기술연구소 2013 산업과학기술연구 논문집 Vol.27 No.2

A self-piercing rivet(SPR) is a mechanical component for joining dissimilar materials. It is used for joining dissimilar material sheets such as aluminum alloy and steel. The self-piercing rivet directly pierces into sheets without drilling sheets beforehand unlike conventional rivets. However, the self-piercing rivet occurs buckling when piercing high strength steel. Therefore, a helical SPR which can pierce high strength steel sheet was designed. In this study, forging process was designed for manufacturing the helical SPR and simulated by using commercial FEM code DEFORM-3D. In the simulation of forging process for manufacturing rivet, process sequence, formability, forging load were investigated. The suitable forging process could be designed by comparisons of simulated results. Experimental trials have been carried out for same conditions as simulated ones. The simulated results agreed with the experimental ones. So, the analytic approach in this thesis is useful to save cost and time in the forging industry

抵抗性 벼 品種을 加害할 수 있는 벼멸구 生態型에 관한 硏究

朴永道,裵泰雄 東亞大學校 1989 東亞論叢 Vol.26 No.1

A series of experiments were conducted to investigate the distribution ratio of the biotypes of brown planthopper(BPH), Nilaparvata lugens Stal, migrated into the rice field of Korean peninsula from southern Chinese continent during the rice crop growing season, the feeding amount, and the emergence rate of BPH biotypes fed on 60 to 70-day-old rice cultivars with different resistance genes. The percent biotype distribution of the female BPH collected in southern coastal regions of Korean peninsula showed that in 1986, 1987, and 1988 the BPH biotype-1 was predominant species accounting for 61.2%, 59.7%, and 52.4%, respectively. Whereas biotype-2 was 21.9%, 29.7%, and 26.2%, and biotype-3 was 17.0%, 12.6%, and 21.4%, respectively. Since Indonesian rice cultavars, IR 36, Cisadane, and Krueng Aceh, to the BPH female adults collected in southern coastal regions of Korean peninsula were shown partially susceptible reaction, the primary source seems to be migrated from the tropics to Korea by way of southern China and the subtropics. The feeding amount of biotype-2 on Cheongcheongbyeo with resistant Bph 1 gene and biotype-3 on Milyang 63 with resistant bph 2 gene was as high as Milyang 23 with no resistant gene. But Gayabyeo with resistant Bph 1 and bph 2 gene was highly resistnat to biotype-1,2,and3. The emergence ratio of the three BPH biotypes on Milyang 23 was higher than on the other rice cultivars, and that of biotype-2 on Cheongcheongbyeeo and biotype-3 on Milyang 63 was as high as on Milyang 23.

방사선 센서의 동작특성

임영화,한상효,김도성,강희동 경북대학교 센서기술연구소 1995 센서技術學術大會論文集 Vol.6 No.1

A Geiger-M□ller(GM) radiation sensor is fabricated by using the vacuum system and gas feeding system. The base pressure of the vacuum system is 1X10^(-7)torr, and two MFCs(0~10sccm, ±1% accuracy of the full scale) are used to control the composition of filling gas exactly. The fabricated GM radiation sensor is simultaneously filled with the mixture of neon and clorine. The mica window(7.43mg/cm^(2)) is attached to the GM radiation sensor. The optimized GM radiation sensor has about 660V starting voltage, 125V plateua length, and 10%/100V plateau slope.

법률사항과 명령사항의 구분기준

박영도 한국외국어대학교 외국학종합연구센터 법학연구소 2003 외법논집 Vol.14 No.-

韓國製造業의 國際競爭力 變化에 對한 硏究 : With Reference to Atutomobile Idustry

許永道,朴琮熙 울산대학교 1988 연구논문집 Vol.19 No.1

本 硏究에서는 기존의 國際競爭力에 對한 槪念과 理論에 대한 比較 考察을 통해 國際競爭力의 槪念, 分析틀, 決定要因, 評價方法 等을 정립해 보았고, 이를 바탕으로 自動車 産業의 國際競爭力 變化 및 競爭戰略의 方向을 추적해 보았다. 결과 우리나라 自動車 産業의 世界的인 競爭位置를 파악할 수 있었으며, 先進 自動車 産業國의 競爭戰略 변화 및 우리나라 自動車 産業의 競爭戰略 변화와 우리나라 自動車 産業의 여건을 고려한 향후 戰略方向을 제시할 수 있었다. 世界 自動車 産業의 주도권은 1920년대의 美國으로부터 유럽, 일본을 거쳐 점차 開發途上國으로 이전되고 있다. 그 중에서도 우리나라는 독자적인 技術能力 向上과 저렴한 勞務費를 바탕으로 급격하게 自動車 産業을 발전시키고 있어 世界 自動車 産業의 제 4차 변혁을 주도할 것으로 예상되고 있다. 이를 위해서 우리나라 自動車 産業이 해결해야 할 과제는 品質水準의 향상을 위한 技術開發, 規模의 經濟를 실현하기 위한 內需基盤의 確保, 生産費의 引下를 위한 效率的인 生産시스템의 開發, 部品業體의 品質競爭力 向上, 輸出地域의 다변화, 製品開發力 및 販賣網의 강화를 위한 先進國 企業과의 보다 긴밀한 協力關係 모색 등이라고 하겠다. In this study, we attempted to establish the concept, analysis framework, determinats and evaluation methods of international competitiveness through a comparative study of existing various concept and theories about international competitiveness. On this basis, we overviewed the changing patterns of international competitiveness and competitive strategy major autmobile industry countries. By this overview, we could find out the competitive position of Korean automobile industry in the world automobile industry, and we could suggest the direction of competitive strategy of Korean automobile industry regarding the experiences of advanced automobile industry countries and the current economic conditions of Korea. In 1920s, American auto-industry had the leading power of world auto-industry, and afterwards the leading power has been transferred to Europe and Japan in due sequence, and recently to developing countries gradually. Among the developing countries, Korea is expected to lead the fourth transformation of world auto-industry because of her rapid growth of auto industry on the basis of her development of relevant technological ability and abundant low cost labour. For the above leadership, Korean auto-industry has to solve the following tasks such as technological development to strengthen the quality competitiveness, maintenance of domestic demand level to acheive the economies of scale in automobile production, development of efficient production system for production cost down, improvement of quality competitiveness of auto-parts suppliers, diversification of export areas, searching for more intensive cooperative relations with advanced countries automobile companies to strengthen the product design ability and the worldwide marketing network of automobile, etc.

폐플라스틱 유동층 열분해 공정연구

선도원,조성호,배달희,박영성 大田大學校 環境問題硏究所 1996 환경문제연구소 논문집 Vol.1 No.-

Process characterization of waste plastics pyrolysis in a bench scale fluidized bed test unit was investigated. Feasibility of commercial scale process such as proper feeding system and reaction control ability were analysed and confirmed based on the reaction characteristics varying with the plaxtics and system assemblies. Eight pure or waste plastic samples were collected from the industrial waste plastics generation source in Korea. Selected samples were HDPE, LDPE autobovile interior, XLPE electric wire coat, synthetic rubber, EVA shoe sole, PS(monomer and styrofoam) and ABS. The pattern of decomposition reflected composition and molecular structure of plastics. Decomposition of polyolifin produced linear paraffinic and olefinic compounds. Recovery of styrene monomer and aromatic compounds were attained from the phrolysis of PS and ABS. However, secondary reaction was monitored was monitored even from the pyrolysis of aliphatic samples of XLPE and EVA.

海外直接投資 理論에 對한 體系的 考察

許永道 울산대학교 1985 연구논문집 Vol.16 No.2

本論文에서는 最近 國際經營學 分野에서 대단한 關心을 집중시키고 있는 海外直接投資에 대해서 그동안 開發된 諸理論들을 體系的으로 分析 整理해 보고, 各理論들이 지니고 있는 限界點을 檢討해 봄으로써 海外直接投資에 대한 一般理論의 開發에 보탬이 되고, 우리나라 海外直接投資 理論의 開發에 出發點을 제시하고자 하였다. 海外直接投資에 관한 理論은 대단히 많고 그 說明力 또한 差異가 많기 때문에 本論文에서는 이들을 理論으로 보지 않고 假設로 다루었다. 先進國의 경우 海外直接投資가 이루어지기 위해서는 企業特有의 優位, 內部化 優位, 立地優位의 세 가지 條件이 갖추어져야 하는 식으로 보이며, 이 立場은 던닝의 折衰理論에 의해 가장 잘 代表 되는 것으로 結論지을 수 있겠다. 개발도상국의 경우에는 先進國 理論을 그대로 適用하려는 立場, 開途國 固有의 理論을 개발하려는 立場 및 先進國 理論을 修正適用 하려는 立場 等이 있으나 대체로 그 理論的인 골격은 折衰理論의 構造를 벗어나지 않는 것으로 보여진다. 따라서, 韓國의 海外直接投資 理論을 開發함에 있어서도 基本的으로 析衰理論의 立場에써 出發해 보는 것이 좋을 듯하다. An attempt is made in this paper to survey systematically various publications on foreign direct investment (FDI) which concentrates a great concern in international business field in recent years. The purpose of this survey is to suggest a guideline for the development of general theory on FDI and a starting point in developing a theory on the FDI of Korea through comparative approach to the various theories. Since there is not one but a number of competing theories with varying degrees of power to explain FDI, they are treated in this paper as hypothesis. The concluding observations may be summarized as follows. In case of the developed countries, the determinants of FDI seem to be consisted of firm-specific advantage, internalization advantage and location-specific advantage, and it seems that the representative hypothesis of this viewpoint is the "Eclectic Theory" develpoed by Dunning. And for the FDI of developing countries, three types of hypotheses could be found. The first was to apply the theory developed for the advanced countries' FDI, and the second was to develop unique theory for the developing countries' FDI, and the third was to apply the modified form of advanced countries' FDI theory. The basic framework of the above three hypotheses seems, however, very similiar to that of the "Eclectic Theory. " Therefore, I think that the viewpoint of "Eclectic Theory" can suggest the guidelines for the development of a basic theory on the FDI of Korea.

연령과 청력역치에 따른 청각장애아동의 음운적 특성

서영란,김진숙,고도흥 한국음성과학회 2001 음성과학 Vol.8 No.2

This research with 40 hearing impaired children was performed to find out the characteristics of the phonological processes for each age, hearing loss degree and aided threshold degree through the transcriptions. The phonological processes. of hearing impaired children are similar to those of normal children with a peculiar type of patterns in phonological processes. The results show that: (1) Between 5 and 6 year old groups the phonological processes were significantly different in palatal backing, glottal replacement and frication; between 6 and 7 year old groups the phonological processes were significantly different in velar fronting, labialization, alveolization and labial assimilation; between 7 and 8 year old groups the phonological processes, labialization, alveolization and alveolar assimilation, however 8 year old group showed more phonological processes than 7 year old group. (2) Between moderately-severe and severe hearing impaired groups, phonological processes were significantly different in the omissions of postvocalic, nasal and velar, stopping and stop assimilation. The differences of severe and profound groups were not found at all. (3) Aided hearing thresholds did not show any significant difference.

採集場所 및 發生世代에 따른 끝동매미충의 殺蟲劑 抵抗性의 差異

朴永道 慶尙大學校 1985 論文集 Vol.24 No.1

This study was carried out to compare the resistance to carbamate (NAC, BPMC) and organophosphate (PAP, diazinon) insecticides in the female adults of green rice leafhopper, Nephotettix cincticeps Uhler, with special reference to their differences in locations and generations. Tested insects were collected from three different locations in Chinju area. The results obtained were as follows: 1, In field-1 generation, the resistance (LD_50) to NAC and BPMC of Yehari strain was higher than that of Jinheungweon (Office of Rural Development) strain by four to five times. Another, there were no differences in resistance to PAP in each location, and the resistance of Omi strain to diazinon was higher than that of Yehari strain by three times. 2. In field-2 generation, the resistance to NAC, BPMC and PAP of Omi strain was higher than that of Jinheungweon strain by two times. But that of Omi strain to diazinon was higher than that of Yehari strain b)r two times. 3. In lab-1 generation, there were no differences in resistance to NAC in each location. But the resistance to BPMC and PAP of Yehari strain was higher than that of Jinheungweon strain by two to four times. And that of Omi strain to diazinon was higher than that of Yehari strain by two times. 4. In lab-2 generation, the resistance to NAC of Omi strain was higher than that of Jinheungweon. strain by two times. Another, Yehari strain was higher than Jinheungweon strain by three times in resistance to BPMC, but there were no differences to PAP in each location. And that of Omi strain to diazinon was higher than that of Yehari strain by two times.