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)

靑少年問題에 一關한 硏究 : Mainly on the analysis of World YouthㆍConsciousness 世界 靑年意識 調査分析을 中心으로

李俊球 弘益大學校 1977 弘大論叢 Vol.9 No.-

This study adopts the Report on World Consciousness which was pnblished in 1973 and compares Korean Youth consciousness with that of American German and Japan Youth. This study gives good research materials. Esrecially Japan has some problems in common with Korea. Therefore I conclude that Korea and Japan help to solve the Youth problem each other, putting special emphasis on the 18 or19 year old youth.

「敎育社會學」歷史에 關한 考察

李俊球 弘益大學校 1981 弘大論叢 Vol.13 No.-

It is generally agreed among Sociologists that Emile Durkheim, in the late 1800s, first clearly indicated the need for a "sociological" approach to the study of Education. During the whole of his teaching life at the universities of Bordeaux and Paris, Durkheim taught educational theory and practice as well as sociology. In his lectures at the Sorbonne, Durkheim began by saying that he viewed education as a Sociologist, and that he considered education "to be something essentically social in Character, in its origins and its function, and that as a result the theory of education relates more clearly to sociology than to any other science." (Emile Durkheim, Education and Sociology (New York, The Free Press, 1956) Durkheim was emphatic in pointing out that there was no single or ideal type of education for all men. He expressed the opinion that differences in sociocultural needs would play a major role in the type of educational programs which are established in various societies. He noted that education is not a static phenomenon but a dynamic and ever-changing process. We have only to note a few of the many current efforts organized around implementing of schools, changing admission criteria, desegregation proposals, preschool programs, and community education to note accuracy of Durkheim's observation. Ⅰ. 敎育社會學史 硏究의 意義 Ⅱ. 敎育社會學 前史 1. 社會的敎育學---敎育에서 社會性의 發見 2. 社會學側---敎育의 認識 Ⅲ. 敎育社會學의 發達과 現狀 1. 프랑스의 敎育社會學 2. 獨逸의 敎育社會學 3. 英國의 敎育社會學 4. 美國의 敎育社會學 5. 日本의 敎育社會學 Ⅳ. 敎育社會學의 發達過程의 特徵 Ⅴ. 參考文獻

轉換期의 韓國社會에 關한 硏究 : An Analysis of Its Structure and Ideology 그 構造와 意識의分析

李璋鉉,李俊球 弘益大學校 1989 弘大論叢 Vol.21 No.1

In this study, the basic direction of Korean society in turning point was divided into two. 1. The changes of consciousness and conduct in all sections of Korean society in cataclysm were analyzed, focusing on the fact that Korean society in cataclysm is a change of its consciousness of value. 2. In regard of social structure of Korea and its change, a change of vocational structure attendant upon industrialization and social stratum, was analyzed. 3. 1 is about a process of converting an industry-oriented society to a human-oriented society as a movement to find a Life worth Living, that is, of moving from a developing society to a valuable society. 2 is about a movement to raise social position ; it is possible to change a social stratum, hence is means that a change of social and vocational positions. In conclusion, Korea society during transition period, strived for a qualitative conversion, not a quantitative one before the 1970s.

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.

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.

「小集團」硏究에 關한 理論的 考察 : -社會學. 社會心理學을 中心으로-

李俊球 弘益大學校 1980 弘大論叢 Vol.12 No.-

(1) Types of Small Groups Sociologists often consider serveral "levels" of social systems, which differ not only n size but in complexity. A common classification of social systems ranges from minimum to maximum complexity and includes the "indivdual," the "dyad" the "small group" the "organization" and the "society" note that the dyad-adialogue between only two interacting individuals-is a level of complexity between the individual and the small group. Hence, for reasons which shall be appearent in later chapters, the small group requires a minimum of three members. Our concern is with the small group and its members. Factors outside the boundaries of that social system shall be deemed lessimportant. But many different types of small groups exist within organizations and societies. And not all of these small groups can be characterized by possessing decision-making purposes. While all small groups reflect many characteristics in commmon, the purpose peculiar to one type of small group renders it quite different from other. small groups with different purposes. Viewing group decision making in perspective necessitates a survey of the common types of groups. And since groups are generally classified according to the purpose they intend to accomplish, awareness of the purposes performed by small groups and for which small groups are formed an maintained. During the past ten or fifteen years the "thaning group," or T-group as it is commonly known, has become extremely popular throughout our society. Despite the numerous variations among training groups, we shall consider all groups which exist for the general purpose of interpersonal growth within the generic definition of training groups.Common varieties of training groups include sensitivity traning groups, encounter groups, confrontation groups, awareneess groups, synanon-type groups, discovery grups, sensory awareness groups, creativity workshops, and a host of other variations too numerous to mention. "Therapy for normal people" is one over simplified explanation of the purpose served by training groups. Generally a training groups attempts to modify the normal behaviors of its members through developing interpersonal sensitivity, human relations skill, mutual trust, and a freer expression of personal feelings, in short, the purpose of a training groups is the interpersonal development and growth of its participating members. While specific devicesand techniques may vary from one kid of training group to another, the basic purpose of all training groups remains similar- behavioral change through interpersonal growth. (2) The Group as a System The idenity of a groups apart from the identities of its individual members-"groupness"-has bee established. A more common method of expressing this same principle is literally a chliche-that is, a group is "more than sum of it sparts." This principle of nonsummativity assumes that individual components comprise a single entity and, turther, is characteristic of a system. A entire body of theoretical knowledge, commonly known as general system theory may be beneficial to furthering our understanding of the group process. A "system" may be defined simply as an entity which behaves as an entity because of the interdependence of its component parts. a group-system, then is a group which behaves collectively as a group because of the interdependece of its members. Every system possesses three elements which describe its existence-structure, function, and evolution. The structure of a system may be regarded as the physical arrangement of components in space at any given point in time, if a cake were considered as a system, the components of the cake are the ingredients-flour, shortening, baking powder, eggs, milk, etc. After they are mixed in the bowl, these ingredients are relatively hmogeneously arrangedd in the structure of batter in which the dry ingredients (e.g., the flour and baking powder) are suspended in the homogeneousq liquid mixture( eggs, milk, shortening). The important thing to remember about systemic structure is the limitation imposed by space. Time is static in the determination of sturcture thus, the above structure of the cake is a description of the arrangement of ingredients as a specific point in time-the batter stage, after ingredients are mixed and before baking, naturally, the sturcture of the cake is different from one point in time to another, thus, a system undergoes continueous structural changes as time passes. (3) Sociometry Sociometric methods are also commonly utilized for observing small groups. Sociometry, whose pictorial representations of social relationships are often known as sociograms, concerns itself solely with selected elements of the social dimension of a system, essentially, sociometric methods seek to discover interpersonal attracions and repulsions among various members of the group, that is, the positive and negative feelings each group member has for each other member. While valuable as an insight into a group's socioemotinal dimension, sociometric methods afford at best only apartial view of the process of group development. By discovering the extent to which members are attracted to other members are attracted to other members and are willing to work with them in other endeavors, the observer has some basis for assessing the degree of cohesivess of that group. But in terms of any knowledge of a group's task dimension, sociometry is quite irrelevant.

朝鮮朝 開化期의 新·舊敎育의 葛藤과 變容에 關한 硏究

李俊球 弘益大學校 1988 弘大論叢 Vol.20 No.1

This article is concerned with what educational heritage the educational innovation of later Yi Dynasty, the prime achiever of the national enlightenment, received from our ancestors, and with how the new education was established and developed on the traditional background of ideology. There were serious conflict and confrontation between the conservatives who stuck to the dualistic pholosophy based on Confucianism and the liberals who advocated educational innovation. Such conflict and confrontation nearly made the Korean education too invalid to struggle against the over-whelmingly surging "European Shock." However, fortunately, our educational leaders had wisdom to take advantage of this crisis to solidify our national conciousness. Therefore, it con be asserted that the new education was started on the dual basis of modernization and national identity. Further, this new education movement took its root as national educational pholosophy even under the Japanese rule, eventually leading to a prime factor of the March lst Independence Movement.