Effect of Impact Velocity on Interface Characteristics of HT‑9 Steel Joints Fabricated by Magnetic Pulse Welding

Jun‑Woo Song,Jin‑Ju Park,Gyoung‑Ja Lee,Min‑Ku Lee,Kyu‑Hyun Park,Soon‑Jik Hong,Jung Gu Lee 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.3

The weldability window in magnetic pulse welding (MPW) is proposed for the end-closure joining of HT-9 steel tubularworkpieces. Based on both theoretical and experimental investigations, the impact velocity of the flyer tube at the momentof collision had a dominant effect on the bonding characteristics of the resultant joints and the optimal impact velocity wasestimated to be in the range of 265–290 m/s in this alloy system. Under the optimal process conditions, no leak was detectedduring helium leak testing. Moreover, the integrity of the joint interface was preserved until the tube section ruptured duringinternal pressure burst testing. For HT-9 steel, the ductile δ-ferrite phase produced by the localized interfacial melting duringMPW acted as an effective obstacle to crack propagation, thereby enhancing the fracture resistance of the joint interface. Allof the results demonstrated the high integrity and durability of the HT-9 steel tube assembly fabricated by the MPW process.

매크로/마이크로 레벨 볼트 결합 구조물에서의 실험적/해석적 방법을 통한 시스템 특성 비교

김봉석,이성민,이문구,이수훈,Jun Ni,송준엽,이창우,하태호 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

As the micro technology and miniaturization of a structure and component in the last couple of decades have been concretely realized, the understanding of structural and dynamic characteristics and prediction of dynamic behavior are indispensable to the miniaturized structures and micro machines. This paper shows the effect of dynamic characteristics in bolt-jointed structures by comparing natural frequencies and mode shapes between macro and micro-scale beams through experimental modal analysis and finite element analysis with a1 8 test models by materials, by size, and by joining condition; that is, SS41 and A16061-T651, micro and macro, and monolithic beam and bolt-jointed beam.

脇痛의 鍼灸治療穴에 對한 文獻的 考察

朴基榮,李浚龜,金永一,朴泰均,辛泳一,黃載然,李賢,李秉烈 대전대학교 한의학연구소 2002 한의학연구소 논문집 Vol.10 No.2

As mentioned above, I have acquired some valuable results about medical treatment with acupuncture and Moxibustion of " Flank pain" after studying oriental medical books . The results Were like below: 1. Medical treatment with acupunctures of Flank pain belonged to the Urinary Bladder Meridian of Foot Taiyang, the Liver Meridian of Foot Jueyin, the Gall Bladder Meridian of Foot Shaoyang. 2. Medical treatmcnt with acupunctures of Flank pain used to Yang-laung-chan(陽陵泉), Gi-gu(支溝), Gi-mun(期門), Kan-su(肝兪) in turn. 3. Medical treatment with Ear acupunctures of Flank pain used to Dam(膽), Sin-Mun(神門), Gan(肝)in turn 4. Acupuncture point of Flank pain were lowrer limb part. chest and abdominal part, back part in turn. 5. Medical treatment with Moxibustion of Flank pain was the most Jang-mun(章門)

大學內의 弘報機能과 大學新聞의 役割에 關한 硏究

李俊球 弘益大學校 敎育硏究所 1978 敎育硏究論叢 Vol.- No.1

This paper aims at the basic study to establish a theory for active use of the function of Public Relations in the college. But this study does not present some concrete plans, for it is carried out only through the references or books. To restore the academic reliability in the college, school authorities should stop the one-way publicty of its policy. The function of public relations should be reexamined for the expression of professors' and students' opinions and active exchange of mutual intention. Overall attention should be paid to college newspaper which plays an improtant part in bringing about effective public relations.

교잡종 찰옥수수에 대한 연구 : Ⅱ. 새로 육성된 찰옥수수 교잡종 "대덕찰"에 대한 농업적 특성 Ⅱ. Agronomic Characteristics of the New Waxy Hybrids "Daedukchals"

이희봉,김효기,김동욱,김준표,정재영,최현구,강윤규 충남대학교 농업과학연구소 2002 농업과학연구 Vol.29 No.2

1. 새로 육성된 4개의 대덕찰 찰옥수수 교잡종에 대한 간장은 대조구인 찰옥 1호보다 큰 반면에 개화기는 약 4∼7일 늦었으며, 모든 공시 교잡종의 주당 분얼수는 한 개이하의 무효분얼로 나타났다. 2. 새로 육성된 대덕찰옥수수의 이삭길이와 직경은 대조구인 찰옥 1호보다 크게 나타났으며, 특히 대덕찰옥수수 1호와 2호의 과피두께는 대구조보다 얇았고, 당도 역시 높게 나타나 우수 교잡종으로 평가되었다. Stem height of the new developed "Daedekchals" waxy hybrids were higher than check hybrid. Chalok #1, while days to tasseling were delayed about four to seven days. Number of tillers per plant of the these new hybrids including check were appeared to be one less as non-effective tiller. Ear length and diameter of the new waxy hybrids were longer and thicker than check, respectively. In addition pericarp thickness of the Daedekchal #1 and #2 among new developed waxy hybrids were thinner and sugar content were higher than check.

韓國近代의 留學과 民族主義 : with Referance to the Refration and Frustration of Their Movement 民族意識의 屈折과 展開

李俊球 弘益大學校 1990 弘大論叢 Vol.22 No.1

The Korean education as the leading factor of historical innovation and consciousness formation during the later 19th century was expected to to play a double role: encouragement of national consciousness and counter power to the rapid international surge. In the context of the contemporary national danger, the Korean students' national consciousness was relatively strong. However, it is noteworthy that their consciousness was gradually refracted and became eventually subject to the change of direction influenced by the outside world trend. Their change of direction is well illustrated by the fact that instead of pursuing their national consciousness movement, they turned toward the movement of independance and national salvation.

日本「開放大學」에 關한 調査硏究 : The university of Tsukuba 「Open University」System

李俊球 弘益大學校 1982 弘大論叢 Vol.14 No.1

The founding philosophy of the University of Tsukuba is in many respects that of an 「open University」 both in national terms and in international terms. Existing Universities are often confined in Marrow specialty arers, inviting the stagnation and hardening of both research and technology and encouraging isolation from real Society, The University of Tsukuba. with this problem in mind, maintains a constant relationship with changing modern Society, and a flourishing international character, while developing more over, a new organization for he functions and administration of research and teaching on a basis of diversity and flexibility. The objectives of the University are therefor, in respect of the pure and applied sciencs, to doepen free and rigorous exchange and liaison between the organs of reseach and teaching on the one hand, and Society at home and abroad on the other hand; to pursue research and teaching while bringing internasonal Cooperation to fruition, and there by to educate able people with a creative intelligence and arich humanity;and to Contribute to the development of science and culture.

敎育文化的 人間學 : -With Special Reference to the Formation of Personality- -人間形成을 中心으로-

李俊球 弘益大學校 1992 弘大論叢 Vol.24 No.1

1.The ideal of education is self-education.Its ultimate aim is to form a personality capable of self-education. 2.In terms of personality formation,the word,culture,comprehensively means all the aspects of custom,system,law,art,and religion based on human spirits. 3.A culture is symbolically represented by the members who live in that culture.In other words,it is a kind of self-representation of the self-formulated people's emotion,thought and behavioral method.This means that the culture and personality formation are directly linked. 4.The culture is mulitipolar and ripple-effective.Therefore,human goal is not achiving unformity,but establishing plural cultures. 5.In this paper,we dealt with this relationship between culture and human affairs,and the mutual relation between education and culture.

韓國近代의 그리스도敎系 學校와 民族主義 : Refraction and Development of National consciousness 民族意識의 屈折과 展開

李俊球 弘益大學校 1991 弘大論叢 Vol.23 No.1

This article is concerned with the relation of christianity to education. In particular, as problems of christianity is considered from a view of nationality, it is very important that christianity is a foreign religion. With that point, acceptance and assimilation of christianity into this land, further, the process of development of the modern education is considered by a christianity turn. Therefore, it can be asserbed that acceptance of Protestantism ad educational movements by missionaries have encouraged the development of the modern education in Korea.

사료용 교잡종 옥수수 연구 : Ⅲ. CNU와 SK계통을 이용한 교잡종 옥수수의 건물중 및 종실 수량

이희봉,김동욱,김준표,김용일,정재영,최현구,문현귀,이충열 충남대학교 농업과학연구소 2003 농업과학연구 Vol.30 No.2

공시 교잡종에 대한 각 지역에서 선발된 우수 교잡종의 간장 및 착수고는 대조구와 비슷한 경향이었으며, 생체 및 건물수량은 분얼수 및 간장과 관련이 큰 것으로 나타났으나 재식 밀도와 기상상태와도 밀접한 관계로 나타났다. 따라서 생체중은 대전지역에서 재배된 교잡종 H67이 대조구인 광안옥에 비해 53.2%로 높았고, 수원에서 역시 41.8%으로 높았으며, 종실수량은 H15과 H67에서 대조구보다 11.7%와 9.7%로 각각 높게 나타났다. 대전에서 분얼성인 H42와 무얼성인 H65에서 대조구보다 9.1%, 5.2%증가하였고, 수원에서는 분얼성이 H42와 무얼성인 H65에서 대조구보다 9.1%, 8.5% 증가하여 교잡종간, 지역간에 큰 차이를 보였다. 한편 후기 녹체성은 무얼형보다 분얼형에서 낮은 경향을 보였는데 SK계통과 교배된 조합에서 우수한 편으로 나타나 우수 교잡종 육성시 중요 고려사항으로 지적되었다. In order to develop the crude forage maize hybrids with high dry matter and grain yield, several hybrids evaluated as superior hybrids at three regions in 2001. They were planted and surveyed again for the second selection in 2002. The selected hybrids showed large difference in some major characteristics according to planting areas and dates(Suwon : April 25. Daejeon : May 15 and Milyang : May 25), but insect and disease injury were similar to check. Fresh and dry weight of the H67 hybrid at Suwon and Daejeon was the highest among hybrids including check, but low in Milyang due to raining after flowering. Grain yield was higher than check in H15 at Suwon H45 and H37 at Daejeon and H67 at Milyang.