민감도 분석을 이용한 겹치기 필릿용접의 용접변수 선정에 관한 연구

정재원,김일수,김학형,손성우,전광석 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

Arc welding process is one of the most important technologies to join metal plates. Robotic welding offers the reduced manufacturing cost sought, but its widespread use demands a means of sensing and correcting for inaccuracies in the part, the fixturing, and the robot. A number of problems that need to be addressed in robotic arc welding processes include sensing, joint tracking, and lack of adequate mathematical models for parameter prediction and quality control. Problems with parameter settings and quality control occur frequently in the GMA(Gas Metal Arc) welding process because of the large number of interactive parameters that must be set and accurately controlled. The objectives of this paper are to realize the mapping characteristics of bead width using a sensitivity analysis and multiple regression method, and finally select the most accurate model in order to control the weld quality(bead reinforcement area, bead penetration area) for lap joint fillet welding.

다양한 방법을 이용한 유방축소술의 임상적 적용

김학수,이상원,정재호,설정현 大韓成形外科學會 2001 Archives of Plastic Surgery Vol.28 No.2

민감도 분석을 이용한 필릿용접용 용접변수 선정에 관한 연구

정재원,김일수,김학형,손성우,김인주,전광석 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-

Arc welding process is one of the most important technologies to join metal plates. Robotic welding offers the reduced manufacturing cost sought, but its widespread use demands a means of sensing and correcting for inaccuracies in the part, the fixturing, and the robot. A number of problems that need to be addressed in robotic arc welding processes include sensing, joint tracking, and lack of adequate mathematical models for parameter prediction and quality control, Problems with parameter settings and quality control occur frequently in the GMA(Gas Metal Arc) welding process because of the large number of interactive parameters that must be set and accurately controlled. The objectives of this paper are to realize the mapping characteristics of bead width using a sensitivity analysis and develop the neural network and multiple regression method, and finally select the most accurate model in order to control the weld qua1ity(bead width) for fillet welding. The experimental results show that the proposed neural network estimator can predict bead width with reasonable accuracy, and guarantee the uniform weld quality.

신경회로망을 이용한 이면비드 폭 예측에 관한 연구

정재원,김일수,박창언,김학형,서주환,김인주,심지연 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-

The development of robotic welding process is a very complex assignment because the system is affected by a number of process parameters which are very difficult to determine or predict in practice. The full automation welding has not yet been achieved partly because the mathematical model for the process parameters of a given welding task is not fully understood and quantified. Several mathematical models to control welding quality, Productivity, micro structure and weld properties in arc welding processed have been studied. However, it is not an easy task to apply them to the various practical situations because the relationship between the process parameters and the bead geometry is non-linear and also they are usually dependent on specific experimental result. Practically, it is difficult, but important to know how to establish a mathematical model that can predict the result of the actual welding process and how to select the optimum welding condition under a certain constraint. In this paper, an attempt has been made to develop an neural network model to predict the back-bead width as a function of key process parameters in the GMA (Gas Metal Arc) welding and to compare the developed models with the experimental results

Rotary type과 linear type 자동흡연 장치에 따른 담배연기 중 타르, 니코틴 및 일산화탄소의 함량 비교

정재훈,김영신,임흥빈,석영선,신주식,이학수 충북대학교 연초연구소 2004 煙草硏究 Vol.19 No.-

본 실험은 type별 흡연 장치의 담배 주류연 포집에 대한 차이를 비교하고자 주류연 중 일반적인 다량의 성분을 측정하였다. 1. 니코틴 함량은 대체로 linear-type 흡연 장치에서 높은 경향 이였으나 유의한 차이는 없었다. 2. 수분 함량은 두 가지 type 간에 유의한 차이는 없었다. 3. tar 함량은 저 농도에서 linear-type 보다 otary-type 흡연 장치가 높은 경향 이였으나 유의한 차이는 없었다. 4. 일산화탄소는 rotary-type과 linear-type 모두 유의한 차이는 없었다. 본 실험결과 ISO 표준 흡연 조건에서 담배 주류연의 tar, 니코틴, 일산화탄소 함량의 측정은 흡연 장치의 type별 통계적으로 유의한 차이는 없는 것으로 판단된다. This study was conducted to compare rotary-type with linear-type automatic smoking machine referred to ISO 3308 in the determination of tar, nicotine and CO in cigarette smoke. Sample were used with 4 kinds of domestic branded cigarettes(tar ; 1, 3, 6, 10 mg/cig) and CORESTA Monitor 4 cigarettes(tar ; 14 mg/cig). Tar and nicotine contents were analysed by gas-chromatograph methods in accordance with ISO 4387 and 10315-1. Determination of carbon monoxide in the vapour phase of cigarette smoke was meaured by NDIR method in ISO 8454. Sample preparation were performed in conditioning room at 22℃, 60 % for 48 hours according to ISO 3402. There was no significant difference between two smoking machine from 1 mg/cig to 14 mg/cig tar cigarettes, but, the contents of three components measured by rotary type showed higher tendency than those by linear type in the case of hight tar cigarettes. The results were the opposite in low tar cigarettes.

종골 골절 치료에 있어서의 전산화 단층 촬영의 유용성

김학준,하권익,윤정로,심재익,김택선,김영배,이우승,최재혁 대한골절학회 2003 대한골절학회지 Vol.16 No.4

스쿠알렌 합성 유전자를 도입한 형질전환 가시오가피

서진욱,정재훈,최용의,이학성,신차균 중앙대학교 유전공학연구소 2003 遺傳工學硏究論集 Vol.16 No.1

The enzyme, squalene synthase, represents a branch point in the isoprenoid pathway capable of diverting carbon flow specifically to the biosynthesis of phytosterol and Triterpenoid. Transgenic Eleutherococcus senticosus plants were prepared by introducing the genes for squalene synthase derived from Panax ginseng (PgSS1), hygromycin phosphotransferase (HPT) and green fluorescent protein (GFP) through Agrobacterium-mediated transformation. Establishment of transgenic plantlets were confirmed by the presence of PgSS1 and HPT bands in the genomic DNA preparation using a PCR method and a Southern blotting. In addition, expression of the introduced GFP DNA was confirmed by observing green fluorescence of GFP from the embroyos. In the in vitro analysis of the PgSS1 enzymatic activities the transgenic plants showed to have 1.5 to 3 times higher than wild type plant, indicating that the PgSS1 genes was well over-expressed in the transgenic plants. Especially the PgSS1 acivities of embroyogenic cell was 120 times higher than those of plantlet.

담배연기성분 중 니코틴함량 측정결과에 대한 불확도 산정

김영신,정재훈,임흥빈,이학수,석영선,신주식 충북대학교 연초연구소 2004 煙草硏究 Vol.19 No.-

담배성분에 대하여 정량분석을 하여 구하는 값은 측정하고자 하는 대상의 참값에 대한 추정값이며, 이는 이상적인 참값으로부터 여러 가지 원인에 의해 벗어나게 된다. 실험 분석 결과는 실험대상에 대한 여러 가지 판단 근거를 제공하는 것이며, 이에 대한 신뢰성의 척도로 불확도가 사용되고 있다. 따라서, 본 연구는 담배연기성분 중 니코틴함량 측정결과에 대하여 신뢰성을 부가시키고, 더욱이 실험과정에서 중요한 불확도의 원인을 찾아내어 해당부분의 불확도를 줄임으로써 보다 정확한 분석결과를 얻고자 이루어졌으며 이 방법으로 추정된 CM4의 측정값과 불확도 표현은 다음과 같다. Nicotine : 1.28 ± 0.01 mg/cig. (신뢰 구간 95.45%, k=2) Measurements by quantitative analysis of tobacco components were the presumed value of a true value. But this measurement was out of ideal true value by various reasons. The aim of this study was to invest with confidence to measurement of nicotine content in tobacco smoke components and to reduce uncertainty by searching uncertainty reasons. Uncertainty of nicotine contents of CORESTA monitor 4 by this method was as follows.

에어로빅 웨이트 트레이닝이 비만여고생의 체조성과 근력 및 근지구력에 미치는 영향

김기봉,이재학,이정아 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.2

The purpose of this study was to analyze the effects of a low-load resistance training on body composition, muscular strength and muscular endurance in high school girls. The subjects of the study were selected with 12 girls who are over 35% fat in U city and they have regularly trained for 50~80 minutes a day in a week and the training program was composed with 8~11 exercise for 12-week period. The statistical methods utilized in the study was the paired t-test and the .05 level was initially established in significance. The findings of this study were as follows ; Body weight, body fat, %fat and body mass index were significantly decreased, but lean body mass was increased after training, and quadriceps extensors and flexors and biceps flexors were significantly increased in muscular strength and muscular endurance. It is concluded that a factors of body composition and muscular strength and endurance were significantly increased in the obese high school girls after 12-week aerobic weight training.

위키 기반 협동적 글쓰기 학습 모형 개발

김두규,박수홍,정주영,이재학 한국초등국어교육학회 2008 한국초등국어교육 Vol.37 No.-

위키는 협동하여 글쓰기를 위한 상호작용적 도구로 활용할 수 있는 웹 기반의 하이퍼텍스트 저작 시스템이다. 위키는 프로토타입 개발을 위한 동료 간의 토의와 협업 도구로 사용되고 있으며, 일반적으로 누구나 자유롭게 정보와 지식을 편집할 수 있는 지식 공간으로 웹을 기반으로 하는 동적 프로그래밍이라고 할 수 있다. 본 연구는 이러한 키의 아이디어를 바탕으로 초등학교 쓰기 학습에서 필요한 학습자들의 협력적 의사소통과 의미구성을 효율적으로 지원하는 위키의 도구적 특성과 학습자 간,학습자와 교수자 간의 시·공간적 제약을 극복할 수 있는 상호작용적 교수·학습을 구성하는 위키식 협동학습 환경으로 협동적 글쓰기를 위한 학습모형을 개발하는 것이다. 이러한 목적을 달성하기 위하여 위키 기반 협동적 글쓰기 학습 모형에 내재되어 있는 핵심 가치와 핵심 학습 활동을 분석하고, 협동적 글쓰기 학습의 핵심 학습활동을 촉진시켜 주는 지원 전략을 도출하였다. 뿐만 아니라 위키 기반 협동적 글쓰기 학습 모형의 초안을 구안하고, 전문가 검토를 통한 수정을 거쳐서 최종적인 위키 기반 협동적 글쓰기 학습 모형을 개발하였다. The purpose of this study is to develope Wiki based learning models for collaborative writing by integrating the features of Wiki to collaborative writing skills. The first research task of this study is to derive the inherent core values and learning activities from Wiki based collaborative learningmodels. Second task is to derive support strategies to promote learning activities (writing strategies, cooperative learning, blending learning) of these models. Thrd task was, based on the extracted core values, core learning activities, and support strategies, to make the draft of learning models of collaborative writing. After modifications by expert reviews, suggested the final Wiki based collaborative learning models. The methods and procedures of this study is below. First, investigated and analyzed the situation and problems by the law questionnaire surveys, and then extract key elements and learning activities from Web using case studies and previous researches of model development. Secondly, construct the daft of the learning models. Finally,revised them consistently by experts review. The result of this research provided the theoretical basis for the learning model through the analysis and research of the core values in learning models. The researcher accepted experts review after make the draft of learning models based on the core values and principles of instructional design. Finally, through the review and evaluation of the experts, the researcher presented final Wiki.based collaborative learning models in writing skills.