Study on the Weldability and Mechanical Characteristics of Dissimilar Materials (Al5052-DP590) by TIG Assisted Hybrid Friction Stir Welding

Hee‑Seon Bang,Seong Min Hong,Atanu Das,Han‑Sur Bang 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

Hybrid friction stir welding, adopting an external pre-heat source in front of the friction stir welding (FSW) tool, is knownas a way of overcoming the disadvantages of conventional FSW; lack of plastic flow and excessive tool wear. In joining ofaluminum alloy to steel, presence of intermetallics (IMC) is essential, but its excessive growth can degrade the joint qualityby its brittleness. In this study, joining of 2.5 mm thick Al5052 aluminum alloy and 1.4 mm thick DP590 high strength steelhas been carried out by FSW and TIG assisted hybrid friction stir welding (HFSW) through experiments and numericalanalysis. Joints characteristics of two process was compared to optimize the process parameters. A 3-D model was developedto estimate the thermal elastic–plastic characteristics of the joints. It was confirmed that the joint efficiency of HFSW jointshas been improved to 84% than that of FSW (74%). 2.74 μm thickness of IMC layer was formed in HFSW joints and satisfiedthe permissible thickness (under 10 μm). The maximum residual stress (σzz) in welding direction was slightly higherat the HFSW joints than at the FSW joints. The overall results from experiment and simulation confirmed that HFSW is aneffective way of joining Al5052 to DP590.

멀티미디어 통신을 위한 인터넷 용량관리 기능

방기천,장희선,신현철 남서울대학교 공학연구센터 2002 공학연구 Vol.3 No.-

The traffic engineering consists of traffic management, capacity management and network planning. In this paper, we present the capacity management function in traffic engineering for next generation multimedia internet services. The link capacity design, shortest-route design and multiple-time network design model is presented. Finally, day-load variation design model and traffic forecasting/reservation model for internet traffic are introduced.

Purge & Trap-GC를 이용한 의약품 필름코팅 정제 중 잔류용제에 관한 연구

장준식,이명자,소유섭,문춘선,이주헌,박희라,김진숙,강경모,이선옥,방성연,유미자,유문균,금오성,이병욱 식품의약품안전청 2000 식품의약품안전청 연보 Vol.4 No.-

의약품은 약물을 생체에 적풋하기 위하여 유효성분의 효과가 언제나 일정하게 확보되고 사응에 편리하도록 만들어지는 것이므로 유효썽분 이외에 약효에 영향을 주지 않는 성분이 첨가되는 경운가 많다. 이 때 사용되는 용매들은 제피의 광택 및 건쪼시간의 단축 등을 위하여 휘발점이 낮을 용매들이 주로 사용되어진다. 본 연구는 의약품 필름코팅정제 중 잔류용매 4종(chlorofonr benzen, trichloro ethylen, 1,4-dioxane)에 대한 변형된 pirge & trap-GC 장치를 이용한 동시분석방법을 개발하였으며, 각 표준품의 RSD 값은 chloroform 3.03%, benzen 3.17%, trichloroethylen 3.69% and 1,4-dioxane 3.41%였다. 또한 시중 유통중인 의약품 50종에 대하여 잔류웅매 양을 측정하였으며, 검출되는 잔류용매는 한 건도 없었다. This study nras carried out to develope the analytical method for the mixture of chlorefonn, benzen, trichloroethylen and 1,4-dioxane simultaneously and determine the remainingorgauic solvents in coating tablets by Purge & Trap-GC. The results were as follouFs ; 1. Chloroform, benzen, trio:tloroethylen and 1,4-dioxane separated by tenax #5 trap by HP-624GC column by terrlperature programming. The peaks were separated completely at retentiontime of 6.88min for chloroform, 8.21min for benzen, 10.38miu for trichloroethylen and 11.95minfor 1,4-dioxane. 2. Standard RSD were individually chloroform 3.03%, benzen 3.17%, trichloroethylen 3.69%and 1,4-diorane 3.41%. 3. 60 samples were not detrcted chloroform, benzen, trichloroethylen and 1,4-dioxane.

강황과 울금 항염중 효과 연구

김영훈, 배덕성, 김정화, 윤현정, 남인영, 김민선, 신희찬, 차현정, 황방연, 이재권 충북대학교 교육개발연구소 2011 한국교육논총 Vol.32 No.3

-본문참고-

Effects of Process Parameters on Friction Stir Weldability in Dissimilar Joints of AA5052 and Advanced High Strength Steel

Hee-Seon Bang,Han-Sur Bang,Kyoung-Hak Kim 대한용접·접합학회 2021 대한용접·접합학회지 Vol.39 No.2

The dissimilar joining of aluminum (Al) alloy and steel has become attractive in the automotive sector to achieve lightweight components. However, joining Al to steel using conventional fusion welding processes is difficult because of their widely varying thermo-physical properties and the formation of intermetallic compounds (IMCs) at the Al-Fe joint interface. In the present study, the dissimilar joining of a 2.5 ㎜ thick AA5052-H32 and a 1.4 ㎜ thick DP590 steel sheet was performed using friction stir welding (FSW). Moreover, the effects of the process parameters on the mechanical properties and microstructure of FS welds was investigated. The tensile test results indicated that a higher heat input with increasing rotation speed and decreasing travel speed contributed to a higher tensile strength. The maximum tensile strength of the FS welds was 178 MPa, which exhibited a joint efficiency of approximately 79%. As a result of scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS) and X-ray diffraction (XRD) analysis, a thin interfacial layer of less than 1 μm thickness comprising Fe₄Al13 IMC was observed at the dissimilar Al-Fe joint interface.

검사 영장청구권의 법적 의의와 타당성검토(下)

( Hee Seon Bang ) 법조협회 2013 法曹 Vol.62 No.2

The Korean criminal judicial system has accepted the doctrine of the attorney`s control of police in criminal investigation and charge just as in the civil law system in Germany and France. So the police are supposed to perform its tasks and duties for criminal purposes under the guidance and supervision of the attorneys (otherwise called ``prosecutors`` traditionally in Korean legal system). This doctrine is designed to abide by the due process of law and secure the goal of ``Rule of Law`` in criminal functions in general. The police, however, have demanded more independent functions and ,besides, even suggested the division of legal powers between the police and the attorneys for the effective operation. In that context, the police have posed questions about the current system and asserted a new approach to the criminal judicial system, in which the police and the attorney(``prosecutor`` in Korea) share the investigation power in cooperation with each other, instead of pre-existed relations of guidance and supervision. And most serious point of changing system is about the principle of the attorney`s power to request the Warrants for arrest, seizure and search etc, which is stipulated clearly in Korean constitutional code and therefore could not be changed despite any kinds of revision of legislation, if without amendment to the Constitution itself. So the police have mentioned the question about such a frame on the basis of legal studies and reports in jurisprudence along with a group of legal scholars in many ways. On the contrary, the prosecution service has referred to such a process as stipulated currently in constitutional code as the important safeguard to the citizen`s right to freedom in criminal cases. Now I think that it is time to review the value and propriety of the constitutional clauses in question from the viewpoint of non-biased logics related to the criminal justice principles. To reach that goal, I look over the origin of the so-called ``prosecutor`` system in Europe to comprehend its roles and functions. In addition, here, I study over the legal position and power of the prosecutor as designed and what the relationship between the prosecutor and the police is like in such European countries. And also I review the American attorney`s power and role in criminal procedure including investigational phase. Finally I review the newly adopted system of prosecutor in England to analyse its function and role-play in English criminal procedure in comparison with those in Korean system and in European countries as well, through which I am going to examine the propriety and legal significance of those clauses giving only the attorneys the power to request the judge`s Warrants in criminal judicial functions. On this occasion this study of mine will be one of helpful resources to solve the question and understand our Korean legal functions in good perspectives.

Transient Thermal Analysis of Friction Stir Welding using 3D-Analytical Model of Stir Zone

Bang, Hee-Seon,Bang, Han-Sur The Korean Welding and Joining Society 2008 대한용접·접합학회지 Vol.26 No.6

양형의 본질과 양형기준에 관한 소고

방희선(Bang, Hee Seon) 대검찰청 2012 형사법의 신동향 Vol.0 No.34

형사재판에 있어서 양형의 중요성과 실제적 가치에도 불구하고 그에 대한 연구와 학습은 거의 이루어지지 않은 채 방치되어 온 실정이다. 대학의 법학교육에도 형법과목의 내용은 범죄론에만 집중될 뿐 양형에 관하여는 아무런 교육이 없고, 그 결과 양형의 문제는 법원 판사들의 현실 업무상 과제로 넘겨져 양형에 대한 학습 연구조차 없이 그저 관행과 전통에 따라 수행되었을 따름이다. 그런 상황이 건국 이래 반세기 이상 진행되다 보니 양형의 본질과 기준을 거론하는 것 자체가 기이한 주장으로 비쳐지는 심각한 낙후성을 드러내고 있다. 전관예우의 비난이나 그에 따른 불균형 양형의 사회적 논란으로 비로소 양형의 합리화에 대한 논의가 유발되었을 뿐 여전히 그 본질 규명과 논리적 해법 탐구에는 다가서지 못하고 있는 게 우리 형사재판의 현실이다. 그러나, 그 사이 선진외국에서는 양형에 대한 지속적 연구와 부단한 탐구로 양형의 본질과 규범성에 대한 괄목할 성과를 이루어 냈고, 급기야 수량화된 객관적 구조까지 도출되기에 이르렀다. 그럼에도 우리 법조는 이를 알지 못한 채 과거의 구시대적 관념에 젖어 새로운 논의의 계기조차 마련하지 못하고 있다. 이에 양형의 개념과 본질에 대한 새로운 이해를 도모하고 그 이론적 기초 위에서 합리적 체계화를 추구할 수 있도록 양형의 본질과 양형기준에 대한 이론적 검토 · 연구의 계기를 마련하는 것이 무엇보다 시급한 현실이라 하겠다. 그런 취지에서 그에 관한 개괄적인 문제제기와 새로운 연구성과를 제시하여 논의의 물꼬를 트고 그릇된 전통 관념의 극복을 위한 법리 연구와 양형론 내지 양형학 정립의 필요성을 촉구하고자 한다. You cannot lay too much emphasis on the importance of sentencing in criminal procedure. Sentencing is the quintessence of the criminal case trial in a sense. So it is a pivotal task to reach a fair and balanced sentence. The korean judiciary, however, has long time failed to achieve that goal. A lot of criminal cases have given rise to fierce social controversies on whether their sentences are fair and justifiable. In this context, we, the lawyers, need to study about the way of fair sentencing. What we have to do urgently is explore the legal nature of sentencing and how to achieve a fair, balanced sentencing. Lots of lawyers and jurists have been making efforts to work on such a goal in western countries lately. Therefore, we need to study about those kinds of approaches to reasonable sentencing. What is the nature of sentencing? How can you make a fair, reasonable sentencing in criminal cases? It has been in controversy whether sentencing is within the judges' discretion or not. It is also controversial whether to make some guidelines for sentencing or not. This study is focused on those questions and their theoretical grounds. I am going to introduce many a legal analysis on sentencing and appropriate solutions including the American guideline system. I hope that many lawyers and scholars will pay attention to this issue and m/ake efforts together to reach the end.

올바른 진술증거의 확보방안 연구

방희선(Bang, Hee-Seon) 대검찰청 2014 형사법의 신동향 Vol.0 No.42

형사사법의 최종목표인 실체적 진실발견은 수사와 재판에 있어서 올바른 증거의 확보와 판단이 핵심이라 할 것이다. 적기에 올바른 증거를 확보하여 정확한 사실인정을 담보할 수 있을 때 비로소 사건의 진상을 규명하여 올바른 범죄 혐의나 유ㆍ무죄의 판정이 가능할 것이기 때문이다. 그런데 이러한 증거의 확보와 관련하여 우리 법제상 진술증거의 수집ㆍ확보에 있어서는 이를 효과적으로 달성할 수 있는 적절한 장치가 없어 사건의 적정한 해결에 장애로 되고 있다는 비판이 근래 나타나고 있다. 인권보장을 위한 과학수사와 객관적 물증 중심의 수사를 아무리 강조한다 하더라도 복잡다단한 범죄현상과 현대범죄의 특성상 피해자는 물론 범죄목격자나 관련자 등 사건관계인의 진술이 필수적인 경우가 허다한 실정이며, 나아가 사건 관련자 진술의 진실성과 정확성이 담보되지 않아 실체규명에 장애를 초래하는 경우 또한 다반사인 편이다. 따라서 이러한 관련자들의 진술증거를 효과적으로 수집ㆍ확보할 수 있어야 함은 물론 그 진술의 진실성ㆍ정확성을 담보할 수 있는 제도적 장치가 마련되어야 한다는 것이다. 그러나 우리의 현행 제도상으로는 피고인, 피의자 이외의 그 어떤 사건 관련자도 임의의 자발적 협조가 있기 전에는 그들로부터 아무런 진술증거를 얻을 방도가 없게 되어 있고, 또한 관련자들로부터 필요한 진술을 얻게 된 경우에도 허위나 왜곡된 거짓진술을 방지할 아무런 장치가 없어 사건의 실체적 진실 발견에 커다란 장애로 되고 있는 현실이다. 이러한 문제점에 대하여 미국, 독일 등 선진외국은 목격자 등 관련자에 대한 강제 소환이나 진술요구 등 합당한 수단을 강구하여 사건해결에 필요한 관련자의 진술 증거를 적절히 확보할 장치를 두고 있고, 나아가 허위의 진술에 대한 제재조치를 두어 올바른 진술증거를 얻을 수 있는 제도적 장치도 아울러 마련하고 있다. 따라서 우리의 경우도 이제 과거의 전통적인 접근법의 한계를 극복하고 올바른 진술 증거를 적절히 확보 가능케 할 유효적절한 제도적 방안을 마련할 필요가 있다고 본다. 신속 정확한 형사사법의 실현을 위하여 필요한 진술을 적기에 확보할 수 있도록 할 뿐 아니라 사실에 부합하는 올바른 진술을 담보할 수 있는 제도적 장치를 마련하여 적법절차에 의한 인권보장과 함께 합법절차에 의한 진술증거의 적정한 확보를 동시에 가능케 할 필요가 있는 것이다. 이를 위하여 우리의 현황 분석과 함께 주요 외국의 관련 제도를 비교 검토하여 우리 현실에 맞는 적정 수준의 제도적 접근법을 모색해 보고자 한다. It is pivotal to properly secure relevant evidences in pursuit of criminal justice. Especially, the attainment of the case-related persons’ statements is most essential in many criminal investigations. The Korean criminal procedure, however, has no proper legal tools to obtain the statements of the case-related persons such as witnesses except through their own voluntary cooperation. Besides, it doesn't have any effective schemes to secure true, right statements of the related people in the investigative phase. Therefore, many lawyers recently begin to suggest the adoption of a new institution for legal method to obtain case-related persons’ statements not only by their own cooperation but also by compulsory measures and furthermore to obligate them to make true, genuine statements during whole criminal process including investigation. Most of the advanced countries such as U.S.A., Germany, France, Italy already instituted appropriate legal methods to obtain the related people’s statements in proper process and to force them not to make false or counterfeit statements in all cases during investigation. In that context, we also need to seek proper legal ways to secure right statements as effective evidences in criminal cases. So I have studied and researched for the advanced countries' legal systems and their functions to reach the goal of criminal justice. Consequently, I suggest that some sort of legal schemes to attain the right statements from witnesses and other related persons in due time and to prevent them from any false statements shall be adopted in Korean criminal system like other countries above.

켄터이너선 고강도 극후판 EGW용접부의 용접잔류응력 특성에 관한 연구

방희선 ( Hee Seon Bang ),고민성 ( Min Sung Go ) 조선대학교 공학기술연구원 2009 공학기술논문지 Vol.2 No.3

Recently, in shipbuilding industries the production trend towards large ships leads to an increase use of high strength ultra thick plates. Especially in super large container ships over 8000 TEU, ultra thick plates of EH36/EH40 over 70 mm thickness and the yield strength 355 MPa is being used in order to satisfy the strength of hull upper deck and hatch coaming of the ship structure. Accordingly, the use of14tra thick plates increases the welding tasks. An alternate welding process such as EGW with high heat input replaces multipass FCAW process for welding ultra thick plates thus improving the productivity. Steel plates below 55 mm thickness, I pole EGW process is applied whereas above 55 mm thickness I pole EGW with FCAW or 2 pole EGW high efficiency welding process is applied. But, unlike existing welding processes EGW produces high heat input which in turn affect the object material and welding material properties strongly. Therefore, limitations for heat input or requirement of post heat treatment exists in case of EGW. Localized high heating during welding, followed by rapid cooling, generates residual stress in the weld which is detrimental to sound welded structure. Therefore, it was important to clarify more precisely the residual stress characteristics caused due to welding in the design stage, in order to ensure the secureness of structure. This study intends to establish the reliability of weld joint by EGW for high strength EH32 TMCP ultra thick plate. For this, heat conduction and thermo elasto-plastic analysis has been carried out on two pass X-groove butt joint model to clarify the thermal and mechanical behaviour (residual stress, plastic strain, magnitude of stress and their distribution and production mechanism) of the weld joint.