항공우주용 리오셀계 탄소/페놀릭 복합재료의 내열성능 평가

서상규(Sang-Kyu Seo),김연철(Yun-Chul Kim),배지열(Ji-Yeul Bae) 한국추진공학회 2020 한국추진공학회 학술대회논문집 Vol.2020 No.11

3차원 유한요소를 이용한 핵연료와 피복관 기계적 거동 해석

서상규(Sang Kyu Seo),이성욱(Sung Uk Lee),이은호(Eun Ho Lee),양동열(Dong Yol Yang),김효찬(Hyo Chan Kim),양용식(Yong Sik Yang) 대한기계학회 2016 大韓機械學會論文集A Vol.40 No.5

원자력 발전소의 반응로에 핵연료 봉으로 이루어진 집합체가 있으며 핵 연료의 연소를 통한 열을 이용하여 발전을 한다. 핵연료 봉은 핵연료와 그를 감싸는 피복관으로 이루어졌으며 연소되는 동안 서로의 상호작용에 대한 해석은 안전성을 평가함에 있어 중요한 사실이다. 본 논문에서는 핵연료와 피복관의 연소 상태에서 기계적 상호작용에 대한 해석 방법에 대하여 제시한다. 온도 해석에 있어서 핵연료와 간극 사이에서의 열전도도가 중요하며 간극 거리와 접촉여부에 따른 접촉 압력이 또한 중요 요소이다. 이에 간극 열전도도는 비결정론적이기 때문에 이를 해결할 수 있는 방법에 대하여 제시했다. 핵 연료의 열팽창에 따른 피복관과의 접촉을 해결하기 위한 계산을 수행하였고 그에 따라 접촉 시 발생하는 응력이 항복함수를 넘어 소성 변형이 일어날 경우 또한 고려하였다. 핵연료의 열팽창에 따라 피복관과 접촉에 의한 소성 변형을 해석하므로 핵연료 봉의 안정성을 평가할 수 있다. 이를 적용하기 위해 3차원 유한요소 모듈을 FORTRAN90을 이용하여 개발하였다. 핵연료와 피복관의 접촉에 의한 탄소성 변형을 주로 다루며 두꺼운 실린더를 통한 간단한 이론 모델을 제시하여 코드에 대해 검증을 실시하였다. In a nuclear power plant, the fuel assembly, which is composed of fuel rods, burns, and the high temperature can generate power. The fuel rod consists of pellets and a cladding that covers the pellets. It is important to understand the pellet-cladding mechanical interaction with regard to nuclear safety. This paper proposes simulation of the PCMI. The gap between the pellets and the cladding, and the contact pressure are very important for conducting thermal analysis. Since the gap conductance is not known, it has to be determined by a suitable method. This paper suggests a solution. In this study, finite element (FE) contact analysis is conducted considering thermal expansion of the pellets. As the contact causes plastic deformation, this aspect is considered in the analysis. A 3D FE module is developed to analyze the PCMI using FORTRAN 90. The plastic deformation due to the contact between the pellets and the cladding is the major physical phenomenon. The simple analytical solution of a cylinder is proposed and compared with the fuel rod performance code results.

균형 말뭉치 구축 방법론의 새로운 모색 : 일본어 문어 균형 말뭉치(BCCWJ)의 분석

서상규 ( Sang Kyu Seo ) 연세대학교 언어정보개발원 2008 언어사실과 관점 Vol.22 No.-

구어 말뭉치 설계의 몇 가지 조건

서상규 ( Sang Kyu Seo ),김형정 ( Hyeong Jeong Kim ) 연세대학교 언어정보연구원(구 연세대학교 언어정보개발원) 2005 언어사실과 관점 Vol.14 No.-

한국어 빈도 조사와 말뭉치의 주석

서상규(Seo Sang-kyu) 한글학회 2017 한글 Vol.- No.316

이 연구에서는, 이제까지 말뭉치를 바탕으로 이루어져 온 한국어 빈도 조사의 성과를 분석함으로써, 언어 연구와 빈도 조사에 말뭉치를 효율적으로 활용하기 위해서 필요한 여러 요건과 문제점을 구체적으로 밝히고자 했다. 또한, 빈도 조사의 정밀성과 신뢰도를 좌우하는 큰 요인은 다름 아닌 말뭉치의 분석과 주석의 방법과 태도임을 밝히고, “정확하고 신뢰할 수 있는 언어 정보”를 얻기 위한 밑바탕으로서의 주석 말뭉치를 어떻게 가공해 나가야 할 것인가 하는 새로운 방향성을 모색하고자 하였다. 한국어 빈도 조사의 역사는 1930년으로 거슬러 올라갈 수 있으며, 낱말 빈도 조사는 최현배, 이승화(1955, 1956)에서 처음 이루어졌다. 이후 1990년대 후반 컴퓨터와 대규모의 말뭉치를 활용한 빈도 조사가 여러 차례 이루어졌으나, 1950년대에 이루어진 성과를 넘어서지 못하고 있었다. 다행히 21세기에 들어서 그 규모와 방법론을 달리하면서 다양한 빈도 조사의 시도가 이루어지고 있으며 구어와 의미 빈도의 조사에까지 이르렀으나, 앞으로 해결해야 할 문제가 적지 않게 남아 있다. This meta-study examines the historical development of Korean language word frequency research in linguistics, which has been based on text corpora. We aim to clarify the various requirements in and problems of effectively using corpora for language studies and frequency research. We find that the methods and attitudes of scholars analyzing and annotating corpora create problems in terms of accuracy and reliability. Therefore, we try to find a new direction on how to process annotated corpora as “high quality linguistic information”, which obviously is essential to study in this field and future research. The history of frequency research in Korean can be traced back to the 1930s, with full-scale and detailed studies conducted for the first time two decades later by Choi Hyun-bae and Lee Seung-hwa (1955, 1956). Then, in the late 1990s, frequency studies using computers and large corpora became common, but failed to improve upon the achievements of the 1950s. Fortunately, in the 21st century, attempts have been made to innovate by varying the scale and methodology. Still, some important problems remain. First, when constructing a large and small balanced corpus to be investigated as one, there is no consensus on the scale of the balanced corpus, the size of the sample, or the method of constructing it. And it is also difficult to directly compare the results with each other. In order to understand the reality of the Korean language by comparing word frequency research results, it needs to be clear that each corpus represents a different, specific register. Second, since frequency research is based on a linguistic analysis of a corpus, a detailed annotation of the corpus is essential. As the size of the corpus grows, the accuracy of the annotation deteriorates, causing a problem in the reliability of the overall frequency result. In many cases, the unit setting and the linguistic interpretation for the frequency research are not sufficiently thorough in the corpus annotation stage. Particularly, there are problems such as the processing of morphemes and words, numbers and numerals, and compound words. Whether symbols or punctuations should be included in frequency also remains unclear. Researchers are also passive about making public their annotated corpora. Third, there are few attempts to normalize the presentation of frequency results. In many cases, only the absolute frequency is presented. Especially, when a comparison between the registers is required, it is necessary to present the normalized results side by side. Fourth, as shown newly in Seo Sangkyu (2015), the ideal presentation method must enable other researchers to see the variation forms of the particles and endings, the spoken form, the dialectal form, and the abbreviation form of all vocabulary in one place. It is desirable to further develop the system so that readers can understand the vocabulary at a glance.

어휘사 연구와 국어정보화

서상규(Sang Kyu Seo) 한국어학회 2001 한국어학 Vol.14 No.-

This article is to examine methodological changes in the Korean linguistics since late 1980s and also to search the new research directions for the Korean lexical history. It will be articulated how to solve or supplement the problems in the precedent researches by analyzing the Korean dictionaries in the seventeenth century as well as other data concerning the history of the Korean language, and this will lead to the assessment of existing studies on the history of Korean done for the last l0 years from the methodological point of view. The ultimate objective of the Korean lexical history is to describe the systemic changes in Korean words, and the alternations in the form and meaning of each individual word. In that perspective, it is essential to conduct the basic researches, the computerization of data of the Korean language history. the development of applications, the expansion of indices, and the refinement of analysis on the form and meaning of each individual word. The considerable number of basic data and research methodo1ogies has already been accumulated until now Obviously, we must start the micro-observation of each individual word, review and supplement the existing research outcomes to identify the macro-lexical system of the Korean language.

한국어 특수 말뭉치의 구축 현황과 그 특징 : 21세기 세종계획의 성과를 중심으로

서상규(Seo Sang Kyu) 한국사전학회 2008 한국사전학 Vol.- No.12

This paper examines the current status of Korean specialized corpus focusing on the 〈21 st Century Sejong Project〉 Special Data Division. The objectives of the specialized corpus, fields of application, and other detailed information such as a size, construction, and other specific features were discussed in this paper. Korean specialized corpus was planned to expand the boundaries of existing corpora composed of 'contemporary Korean written language' and to make a database that contains Korean language resources as a whole by comprising the variations across time and space as well as spoken and written language. In addition to expanding the written language corpora which include data from 15th century to the present time, the data of both south and north Korea and China and former Soviet republics, the project developed -a large-scale spoken language corpus consisting of contemporary Korean natural locutionary acts, which not only made the research on colloquial language possible but research on- comparative study of spoken and written language feasible as well. When developing multi-lingual parallel corpora, the diversity of the contents and the quality of translation was considered in a great measure, so that we could use a high quality parallel corpus. Additionally, it is regarded as desirable to take steps to get the permission from the authors for the use of data in research and technology development.

항공우주용 리오셀계 탄소/페놀릭 복합재료의 내열 성능 평가

서상규(Sang-Kyu Seo),김연철(Yun-Chul Kim),배지열(Ji-Yeul Bae),함희철(Hee-Chul Hahm),황태경(Tae-Kyung Hwang) 한국항공우주학회 2021 韓國航空宇宙學會誌 Vol.49 No.5

리오셀계 탄소/페놀릭 복합재료의 항공우주용 내열 부품 적용 가능성을 확인하기 위하여 내열 성능 평가 및 열 해석을 수행하였다. 탄소/페놀릭의 열반응 평가는 내열성능평가모터(Thermal Protection Evaluation Motor, TPEM)로 수행되었다. 본 논문에서는 열 해석을 위해 유체의 경계층 해석을 고려한 경계층 적분 코드와 삭마 및 열분해를 고려한 MSC-Marc 2018 코드를 사용하였다. 추진기관의 압력 곡선, 연소 시험 후 절개된 목삽입재 시편을 통하여 삭마 및 단열성능을 분석하였고, 리오셀계 탄소/페놀릭 복합재료의 열반응은 레이온계 탄소/페놀릭 재료와 유사하였다. 연소 시험을 통한 결과를 바탕으로 국산 리오셀계 탄소/페놀릭의 항공우주용 내열 부품으로의 적용 가능성을 확인하였다. Heat resistance performance evaluation and thermal analysis were performed to confirm the applicability of the lyocell-based carbon/phenolic composite material for heat-resistant parts for aerospace. Heat resistance performance evaluation of carbon/phenolic was conducted by Thermal Protection Evaluation Motor (TPEM). In this paper, boundary layer integration code considering the boundary layer analysis of combustion gas and MSC-Marc 2018 considering ablation and thermal pyrolysis were used for the thermal analysis. The ablation and thermal insulation performance were analyzed by the pressure curve of test motor and the cut carbon/phenolic specimens. The thermal response of the lyocell-based carbon/phenolic material was similar to that of the rayon-based carbon/phenolic material. Based on the results through the combustion test, the applicability of heat-resistant parts for aerospace to which domestic lyocell-based carbon fibers were applied was confirmed.

한국어 정보 처리와 연어 정보

서상규(Sang Kyu Seo) 국어학회 2002 국어학 Vol.39 No.-

N/A

고체 로켓 노즐의 경계층 해석과 유한차분법을 이용한 탄소/페놀릭의 열반응 해석 연구

서상규(Sang Kyu Seo),함희철(Hee Cheol Hahm),강윤구(Yoon Goo Kang) 한국추진공학회 2018 한국추진공학회지 Vol.22 No.1

The thermal response of carbon/phenolic used in a solid rocket nozzle liner was analyzed. In this paper, the numerical analysis of the thermal response of carbon/phenolic consists of (1) the integration equation of the boundary layer to obtain the convective heat transfer coefficient of the combustion gas on the rocket nozzle wall and (2) 1-D finite difference method for heat conduction of carbon/phenolic to calculate the ablation, char, and temperature. The calculated result was compared with the result of a blast-tube-type test motor. It is found that the calculated result shows good agreement with the thermal response of the test motor, except at the vicinity of the throat insert.