원자로 입출구 노즐 이종금속 용접부 Weld Inlay 레이저 클래딩 공정 개발

조홍석,정광운,모민환,조기현,최동철,이장욱,조상범,Cho, Hong Seok,Jung, Kwang Woon,Mo, Min Hwan,Cho, Ki Hyun,Choi, Dong Chul,Lee, Jang Wook,Cho, Sang Beum 한국압력기기공학회 2015 한국압력기기공학회 논문집 Vol.11 No.1

This study was investigated to develop process technology of laser cladding with austenite stainless steel for Weld Inlay repair of dissimilar metal weld in reactor vessel in/outlet nozzles. Weld Inlay experiments were performed by laser cladding repair system consisting of common manipulator, laser apparatus and welding process scheduler, etc. Single pass welding experiments were conducted in order to obtain the optimum welding process parameters for filler wires of ER309L and Alloy 52M before multi-layer laser cladding. Based on the above obtained results, multi-layer laser cladding experiments were carried out, and welding qualities for weld specimens were estimated by PT, OM, SEM and EDS analysis. Consequently, it was revealed that multi-layer laser cladding on austenite stainless steel using filler wires of ER309L and Alloy 52M could be possible to meet ASME Code standard without any weld defect.

용접 공정에서 자기력의 효과에 대한 연구

조홍석,박익근,이우람,Cho, Hong Seok,Park, Ik Keun,Lee, Wooram 대한용접접합학회 2014 대한용접·접합학회지 Vol.32 No.5

Welding and joining technology has become a core field. Therefore it is more widely applied to nonferrous metals, inorganic and polymeric materials. That is because the high performance, high function and diversification trend of materials used as industrial technology develops. In the laser welding process, STS 304 and SCP1-S were used as the base materials, the output density was fixed $7MW/cm^2$, the protective gas was argon(Ar) and the transfer rate was fixed 5 mm/sec. and it was progressed while the magnetic field is gradually increasing by 100 mT ranging 0 to 400 mT. The tensile test showed in average about 6 % tensile strength improvement in the case of the laser welding process using the magnetic fields. In the shielded metal arc welding process using SPHC only or the combination of SPHC+STS304 as base materials. The electric current was set at 80 Amperes and the protective gas used argon(Ar) the same as the laser welding process and the strength of magnetic fields. In the shielded metal arc welding process using the magnetic fields, the tensile tests showed about 5 % tensile strength improvement in the case of using SPHC only, 3 % tensile strength improvement in the case of using the combination of SPHC+ STS304. In comparing the results of numerical analysis to the results of experimental tests, it was revealed that the temperature, thermal stress distribution and the behavior of molten pool were similar to those of real tests. Consequently, it may be considered that the numerical assumption and the analytical model used in this study were reasonable.

원전 가압기 히터슬리브 J-Groove 이종금속 용접부 보수를 위한 용접 공정변수 최적화에 관한 연구

조홍석,박익근,정광운,Cho, Hong Seok,Park, Ik Keun,Jung, Kwang Woon 대한용접접합학회 2015 대한용접·접합학회지 Vol.33 No.1

This study was performed to develop repair technology for J-Groove dissimilar metal weld of pressurizer heater sleeve in nuclear power plants. Pad, J-Groove automatic welding and mechanical machining equipments to develop repair technology using 'Half Nozzle Repair' were designed and manufactured. To obtain the optimum welding process parameters during Pad temperbead overlay welding, several welding experiments using Taguchi method were conducted. Weldability of Pad overlay weld specimens was estimated by PT/RT test, FE-SEM, EDS and Vickers hardness test. Also, J-Groove welding to adjust weld shape conditions requiring in ASME Code was carried out and its integrity of weld specimens was evaluated through PT/RT test and optical microscope. Consequently, it was revealed that Pad and J-Groove overlay welding for dissimilar metal weld of pressurizer heater sleeve could be possible to meet Code standard without weld defect.

원자로 입출구 노즐 Alloy 82/182 이종금속 용접부 Weld Inlay 적용 후 초음파나노표면개질이 잔류응력 완화에 미치는 영향

조홍석,박익근,정광운,Cho, Hong Seok,Park, Ik Keun,Jung, Kwang Woon 대한용접접합학회 2015 대한용접·접합학회지 Vol.33 No.2

This study was performed to investigate the effect of ultrasonic nano crystal surface modification (UNSM) on residual stress mitigation after Weld Inlay repair for butt dissimilar metal weld with Alloy 82/182 in reactor vessel In/Outlet nozzle. As-welded and Weld Inlay specimens were made in accordance with design standard of ASME Code Case N-766, and two planes of their weld specimens were peened by the optimum UNSM process condition. Peening characteristics for weld specimens after UNSM treatment were evaluated by surface roughness and Vickers hardness test. And, residual stress for weld specimens developed from before and after UNSM treatment was measured and evaluated by instrumented indentation technique. Consequently, it was revealed that the mitigation of residual stress in weld metal after Weld Inlay repair of reactor vessel In/Outlet nozzle could be possible through UNSM treatment.

경관시뮬레이션분석기법을 활용한 도심권 문화재의 조망축 확보방안에 관한 연구 -통영시 도심 내 국가지정문화재의 역사문화환경 보존지역을 중심으로-

조홍석,Cho, Hong-Seok 한국건축역사학회 2012 건축역사연구 Vol.21 No.3

If cultural Heritageis located in the downtown, conservation areas was developed or is being developed In most cases Therefore, in this case, the relative height of the building during construction than the regulatory limit is reasonable, is emerging need to be objectified. This study was utilizes GIS analysis techniques for 'View Corridor' and building height standards were determined. First, 'View Corridor' set and building height restrictions for the analysis of urban environmental factors were analyzed in. In particular, the topography and urban planning, and existing buildings, including the distribution of the physical urban environment, with detailed analysis on the major historical and cultural assets with a combination of a review of the impact factor for the formation of the urban landscape recognize the scope has been expanded. Second, the key selection criteria for View point largely focused on cultural Heritageand the surrounding communicative point of view and, consequently, connectivity, and symbolism, accessibility, analysis, factors such as Prospect, setting the standards by applying a detailed assessment of each item the main view point were derived. Third, the derived key View point on the terrain and landscape characteristics simulation analysis carried out by considering together the main axis, and this suggests a reasonable height for the proposed standards.

근대 적벽돌 생산사에 관한 연구

조홍석,김정동,Cho, Hong-Seok,Kim, Chung-Dong 한국건축역사학회 2010 건축역사연구 Vol.19 No.6

According to it, a final goal of this study sets up 'Renovation of the Red brick architecture' and development of theoretical foundation and substantial conservation about Red brick architecture through historical records must be settled without delay. Firstly, it analyzes related terminology and adjusts brick architecture's history and features for architectural authenticity about Red brick architecture. It would study production and construction process of brick in korea. From analysis of records, brick of traditional meaning is 'Jeondol' and western brick of modern meaning is 'Red brick'. 'Brick' defines a common designation. This study shows definition of words based on documents published until 19th century and a korean language and architecture terms dictionary. In view of this results, the meaning of brick which combines different types extensively uses 'Chu', 'Jeon', 'Byeok' according to the purpose of use and the current of the times. In case of 'Jeon', it uses jointly different types such as '塼', '?', '?'. but '塼' is frequently used. Even though these words like 'byeok' used individual or combination types until the late 19th century, there is no use because of japanese terms in japanese colonial. After liberation, it was the term of the traditional brick. Brick is generally used through modern times. In an unabridged Korean language dictionary, it defines this term as orthodox korean '壁乭' and '?乭'. At that time of japanese colonial, 'Yeonwa(煉瓦)' used in combination with brick. Due to influence it, it partly uses until now but it is not in common use. Also, a Korean language dictionary contains transcription of 'Yeonwa' with same definition as 'Byeokdol'. In the other side, it results from translating japanese into Korean. It would make exact definition of 'Yeonwa'.

문화재 재난안전도 평가지표 개발 연구

조홍석(Cho, Hong Seok),서현정(Suh, Hyun Jung),이명선(Lee, Myung Sun) 한국방재학회 2017 한국방재학회논문집 Vol.17 No.4

본 연구는 궁극적으로 효율적인 문화재 재난안전관리시스템 개발을 위하여 문화재의 특성을 고려한 재난안전도 평가지표를 개발하는 것을 주된 목적으로 하였다. 구체적으로, 관련 개발동향을 분석하고, 문화재의 특수성을 고려한 재난안전 평가지표를 개발하는 한편, 데이터베이스 구축을 위한 문화재 유형별 점검항목을 도출함으로써 문화재 재난안전관리의 세부적인 틀을 제안하였다. 평가지표는 문화재 재난안전관리적 특성을 감안하여 크게 음성지표와 양성지표로 구분하는 한편, 범용적 활용을 위해 단위 문화재의 개별적 특성에 따라 개념구분이 변동될 여지가 있는 지표의 경우, 중성지표를 별도로 구분하였다. 이러한 평가지표를 기준으로 문화재 및 재난 유형별 세부 점검항목을 도출하였다. This study is primarily aimed at developing a hazard assessment indicator taking into account the characteristics of cultural assets in order to develop the disaster management system for cultural heritage. Specifically, after analyzing the trends of the relevant development we proposed a detailed framework of the disaster safety management of cultural heritage through developing a disaster safety assessment indicator taking into account the specific characteristics of the cultural heritage and deriving check points according to the type of cultural assets, resulting in the establishment of the database. The evaluation indicators are divided into the negative and positive indicator according to the characteristics of disaster management. For the purpose of general application, the indicators are divided separately into the neutral indicator. Based on these metrics, detailed inspection items were developed according to the types of cultural heritage and disaster.

문화재 유형별 현상변경 검토기준 마련 연구

조홍석 ( Hong Seok Cho ),박현준 ( Hyun Joon Park ),이유범 ( You Beom Lee ),이천우 ( Cheon Woo Lee ),김철주 ( Chul Ju Kim ),박정섭 ( Jung Seop Park ),김상동 ( Sang Dong Kim ) 한국전통조경학회 2015 한국전통조경학회지 Vol.33 No.4

1962년 제정된 문화재보호법은 지속적인 개정을 통해 급속한 경제성장 과정에서 문화재의 체계적인 보존·관리 및 활용에 그 역할을 다해왔다. 특히, 2000년에는 문화재 영향검토제도를 도입하고, 2006년에는 국가지정문화재 현상변경 허용기준 마련 지침을 제정하며 문화재 및 역사문화환경의 보존과 더불어 행정효율성 제고, 정주환경 개선에 상당한 기여를 하고있다. 그러나, 문화재 가치에 대한 국민의식 향상과 문화유산을 활용한 지역 활성화의 필요성이 대두되는 동시에 문화재 가치 및 유형적 특성, 토지이용실태 등 주변 여건을 적의 반영하지 못하는 일부 허용기준을 적용함에 따라 주민 불편사항이 계속 제기되고 있어, 본 연구는 문화재의 핵심가치를 명확히 하고, 이를 반영한 문화재 유형별 현상변경 검토기준 마련을 목적으로 하였다. 이에 문화재보호법 및 관련 지침·매뉴얼, 각종 연구자료 등의 분석을 통해 물적 특성 및 본연의 가치를 적극적으로 보존·관리하기 위한 경관관리 중점지표를 설정하고, 현상변경 관점에서 문화재 유형분류체계를 재분류하여 현상변경 검토기준을 제시하였다. 이를 통해, 단기적으로는 문화재 가치 및 유형별 특성을 반영한 역사문화환경의 체계적 관리와 검토기준의 일관성을 확보하는 한편, 이를 적용한 허용기준의 조정을 통해 기준설정에 대한 대국민 이해도 증진을 도모함으로써 문화재 관리행정에 대한 만족도가 제고되길 기대한다. The Cultural Properties Protection Law Act 1962 has been achieving its role for systematic preservation, management and application of the cultural heritage under rapid economic growth circumstances through continuing revisions. Introduced the influence review system for cultural heritages in 2000, and legislated the guideline for the state-change allowance standard for the National Cultural Heritage in 2006 in specific, the law has been contributing significantly for the cultural properties and historical/cultural environment preservation, along with increase in administrative efficiency and improvement on settlement environment. However, increase in public awareness about the cultural property``s value and the needs for the local revitalization by utilizing the heritages, while some allowance standard not peoperly delivering the surrounding conditions, such as the value of the properties and their substantial characteristics, land utilization, etc. being applied, complaints from the local residents are increasing continuously. Thus this research focuses on clear vision/value of the heritage and apply them to create the review criteria for the state-change allowance per heritages. Here we set the Focus of Landscape Management Indicators in order to actively preserve and manage the physical characteristics and the native value by analyzing the Cultural Heritage Protection Laws and related guidelines, manuals and research papers, and redesign the cultural propertiy``s classification scheme and propose the Review Standard for state-change from the view point of changing the current state. With this research, we expect increase in the satisfaction for the Property management system with public understanding promotion regarding the Standards by applying the reviewed state-change allowance Standards, white securing the consistency for the review criteria as well as the systematic management of historical/cultural environment with their typification characteristics and the value for short-term.

KEPIC P-No. 미지정 재료 등가표 개발 방법론

조홍석(Hong Seok Cho),이장욱(Jang Wook Lee),정광운(Kwang Woon Jung),송상우(Sang Woo Song),이상훈(Sang Hoon Lee),손명성(Myoung Sung Sohn) 대한용접·접합학회 2016 대한용접학회 특별강연 및 학술발표대회 개요집 Vol.2016 No.4

한 ․ 미 FTA의 무역전환효과 패턴과 사례* -대미 수입 품목(HS 10단위) 분석을 중심으로-

조홍석(Hong-seok Cho),이정윤(Jung-yoon Lee) 한국국제상학회 2016 國際商學 Vol.31 No.4

Purpose : The purpose of this study is to analyze the trade diversion effect of KOR-US FTA and to review actual cases. Research design, data, methodology : Based on HS 10 digits, this study extracted all 8,386 items imported from the US by Korea. During the analysis period (2011~2014), we analyzed the changes in the market share on of 86 items imported from the US, Japan, China and the EU. Also, RCA index was used to confirm the trade diversion effect of detailed items. Results : As a result of the KOR-US FTA, it was confirmed that Korea s imports from the US were affected by trade diversion effect, which was mainly a result of the conversion of imports from Japan. During the anlayis period, the EU, which prevailed FTA with Korea, was enjoying the trade conversion effect more. Conclusions : Most of the trade diversion effects of the KOR-US FTA occur in items that had comparative advantages in the past. If related research continues in the future, it is expected to elucidate the dynamics of global trade in more detail. 본 연구의 목적은 한 ․ 미 FTA 발효로 인해 한국의 대미 수입에서 발생한 무역전환효과를 분석하는 것이다. 국내외 경제 및 무역환경 변화가 미치는 영향을 최소화하기 위해, 분석기 간(2011~2014) 동안 전체 수입의 연평균증가율과 유사한 86개 수입 품목을 선정하고 이들 품목의 미국, 중국, 일본, EU 등 주요 수입시장 점유율 변화를 분석하여 무역전환효과를 살펴보았다. 분석결과 한 ․ 미 FTA는 한국의 대미 수입에 상당한 무역전환효과를 창출하고 있었 는데, 이들 대부분은 일본으로부터 수입선이 전환된 것으로 평가된다. 하지만 같은 시기 무역전환효과는 미국보다 EU가 더 크게 누리는 것으로 나타나 FTA 선점효과의 중요성을 시사 하고 있다. RCA 분석결과, 무역전환효과가 발생하는 수입 품목은 대부분 과거에도 수입 비교우위가 있던 품목들이 FTA 발효 이후 경쟁력이 더욱 강화되는 패턴이었는데, 일부 품목의 경우 과거에는 비교열위였으나 FTA 체결로 비교우위 경쟁력을 확보하는 사례도 발견할 수있었다. 글로벌 경제의 불확실성이 높아지는 오늘날, FTA로 인한 무역전환 및 창출효과에 대한 세밀한 연구가 지속된다면 글로벌 무역활동에 내재된 매력과 역동성을 보다 다양하게 밝힐 수 있을 것으로 기대된다.