初期 缺陷形狀에 따른 表面龜裂傳播 特性에 關한 硏究

李龍福,金鍾鉉,李錫俊 弘益大學校 1990 弘大論叢 Vol.22 No.2

In this study, the diameters and depths of the intial surface crack configuration on the specimen was discharge processed differently and considered about propagation behavior and fatigue lifetime of the surface fatigue crack in each case. The result of this study are Summerized as follow; 1. Under the given constant condition, aspect ratio is regular in surface crack propagation, and early its differenceis large according to the initial surface crack configuration but it shows the same change aspect according to the propagation of the crack. 2. In general, for constand initial crack depths we may expect that initial crack lifetime is increased as diameter of specimen is increased because of relaxation of the stress concentration. Practically, however it is different according to the crack. 3. Early, Surface crack configuration has semi-circle and it has semi-elliptical according to crack propagation. 4. When the initial surface crack aspect ratio is in the range of 5∼6, the initial surface crack is propagated to inner surface under the condition, which ratio is smaller than the range. In the ratio is lager than that range, crack is propagated to outer surface.

제2종 중도절단에 근거한 지수분포의 신뢰함수 추정

강석복,서영수,이광호 嶺南大學校 基礎科學硏究所 1997 基礎科學硏究 Vol.17 No.-

In this paper, we shall propose several reliability estimators in the two-parameter exponential distribution, and compare the proposed estimators in terms of the MSE through the Monte Carlo simulation.

보육시설 과학 특별활동 프로그램의 개발과 적용

조복희,곽혜경,한유미,양연숙,손경화 한국영유아보육학회 2003 한국영유아보육학 Vol.0 No.32

The purpose of this study was to develop early childhood science activities, which could be utilized as an extracurricular program in the day-care center. The program is based on the Constructivist theory(Piaget and Vygotsky) and the nation-wide survey data on the extracurricular programs and science activities in the day-care center. After the manuals for the program was monitored and corrected by the professionals, the application of each activities was empirically tested by the teachers in the day-care setting. The effects of the sample program(6 activities) were conducted using Tegano, Sawyers & Moran(1989)'s Scientific problem-solving scale and Lee(2001)'s Scientific attitude scale. Subject of thirty nine children were administered by the pre-test and post-test and experimental group participated the program for six weeks. The results showed that the program was effective for enhancement of scientific problem-solving ability and scientific attitude of young children in day-care setting.

매스매티카를 이용한 광대역 혼합트래픽의 분석

윤복식,김동석,성시영 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.4 No.-

Since the introduction of Mathematica in 1988, it has been succesfully utilized in various research fileds including mathematics and physics. In this study, we use the numerical and graphical power of Mathematica to analyze the voice traffic and the video traffic mixed with voice traffic under the B-ISDN environments. We adapt the fluid flow approximation as the basis of traffic modelling. The individual video source is modelled as a 3-state continuous time Markov chain. We present both numerical examples and Mathematica procedures in order to demonstrate the convenience of Mathematica as well as the validity of the model.

청소년 식이태도와 식이행동의 횡문화적 연구

백영석,안동현,조연규,남정현,최보율,강윤주,고복자 大韓神經精神醫學會 1999 신경정신의학 Vol.38 No.3

연구목적 : 청소년을 대상으로 장애가 있는 식이태도 및 식이행동과 관련된 요인들에서 인종과 문화적 차이가 있는가를 보는 것이다. 방 법 : 1996년도에 3129명의 중고등학교 남녀 학생을 대상으로 학교 장면에서 신체 계측과 설문지를 통하여 수집하였으며 연령은 13세부터 16세 사이의 학생들로 분포되었다. 학생들의 분포는 서울 지역의 663명, 양평 지역의 821명, 조선족이 사는 연길 지역의 830명 그리고 한족이 사는 길림 지역의 815명이었으며, 그들은 모두 키, 몸무게, 신체질량지수, 부모의 수입, 아버지의 학력, 체중조절 설문지, 신체상 척도 및 식이태도검사 등의 내용을 완성하였다. 결 과 : 신체질량지수(BMI)에서는 지역, 성별, 사회경제적 상태에 따른 차이가 없었다. 연길과 길림 지역의 학생들이 서울과 양평 지역의 학생들보다 심한 저체중과 심한 과체중을 갖는 학생들이 많았다. 연길과 길림 지역의 학생들이 서울과 양평의 학생들보다 식이태도검사(EAT-26)의 평균치가 높아 식이태도와 식이행동이 나빴다. EAT-26의 20점 이상인 식이장애의 고위험군은 연길 지역의 학생이 6.9%로 네 집단 중에서 가장 많았다. 한국의 양평지역과 서울 지역의 학생들이 신체상 척도(BIS)의 평균치가 연길 지역과 길림 지역의 학생들보다 의미있게 높았다. 즉 한국의 학생들이 중국의 학생들보다 자신의 신체에 대하여 부정적인 생각을 갖고 있었다. 체중조절 행동의 유병율은 서울 지역 학생들이 26.7%, 양평 지역 학생들이 23.2%, 연길 지역 학생들이 10.6%, 그리고 길림 지역 학생들이 4.6%이었다. 식이조절과 운동은 한국의 학생들이, 식이조절과 약물사용은 중국의 학생들이 가장 많이 하는 방법이었다. 결 론 : 본 연구를 통하여 한국과 중국에서도 식이장애가 결코 적지 않을 것이라는 사실을 확인하였고, 식이장애는 인종과 사회문화적 요인에 의해 크게 영향을 받는다는 것, 마지막으로 식이태도와 식이행동 및 그와 관련된 요인들을 통해서 네 지역간의 문화전이 상태를 확인할 수 있었다. Objectives : The goal of this research was to attempt to examine ethnic and cultural differences in factors associated with disordered eating attitudes and behaviors. Methods : Data were collected from the four groups of 3,129 high school students aged between 13 and 16 years who completed school-based survey conducted in 1996. The students (663 Korean urban, 821 Korean rural, 830 Korean-Chinese and 815 Chinese adolescents) completed an instrument which assessed weight, height, Body Mass Index(BMI), parental income, father's level of education, weight control questionnaire, Body Image Scale(BIS), and eating attitudes and behaviors using the Eating Attitude Test-26(EAT-26). Results : BMI did not vary significantly by race, sex, and socioeconomic status. There were many severely underweight and severely overweight students among Korean-Chinese and Chinese than among Korean urban and Koran rural students. The EAT-26 mean scores of Korean-Chinese and Chinese subjects were significantly higher than those of Korean urban and Korean rural subjects. The EAT-26 mean score of Korean-Chinese was the highest among the four racial groups. The prevalence of high risk EAT-26(EAT-26≥20) students of Korean-Chinese was 6.9% which was the highest among the four groups. The BIS mean scores of Korean rural and Korean urban subjects were significantly higher than those of Korean-Chinese and Chinese subjects. The Korean subjects were more dissatisfied with their body than the Chinese. The prevalences of weight control behaviors were 26.7% in Korean urban, 23.2% in Korean rural, 10.6% in Korean-Chinese, and 4.6% in Chinese subjects. Dieting and exercise were most popular for weight reducing in Korean subjects. Dieting and drug use were most popular in Chinese subjects. Conclusion : These data suggest that there must be many eating disorder patients in Korea and China, and the eating attitudes and behaviors are influenced by ethnic and cultural factors. Implications for understanding sociocultural influence on eating attitudes and behaviors and acculturation are discussed.

冪函數 分布의 로렌쯔 曲線과 지니 指數의 推定

姜錫福,趙瑛錫 嶺南大學校 基礎科學硏究所 1991 基礎科學硏究 Vol.11 No.-

In this paper, we obtain the maximum likelihood estimator, the uniformly minimum variance unbiased estimator and a strongly consistent asymptotically normal unbiased estimator for each of Lorenz curve and Gini index of a power function distribution. The mean square error of each estimator is derived in terms of several special functions. The unmerical values of the mean square errors are also obtained.

고장시간 분포 추정을 위한 단일화된 접근 방법

김동석,윤복식,양경아 弘益大學校 科學技術硏究所 1996 科學技術硏究論文集 Vol.7 No.1

In this paper, we propose a simple and effective life distribution model based on piecewise Weibull failure rate function, called PWF model and introduce a simple method to estimate the parameters in PWF model based on the sequential partial F test and the least square method. All the procedures are computer coded and various numerical application exmples are also given. The results in this paper can be used to analyze failure time data almost automatically under quite general environment.

Kanban함수를 이용한 Kanban시스템의 운영에 대한 연구

이상복,강석호 한국경영과학회 1995 한국경영과학회지 Vol.20 No.2

Kanban 시스팀의 초기 Kanban 갯수 결정문제는 Kanban 시스팀의 최적 운영 문제 중 하나이다. 생산 공정 구조가 일반 형태를 갖는 Kanban 시스팀에서는 초기 최적 Kanban 갯수 결정 문제는 수학적으로는 정수계획법으로 모델화 되기 때문에 발견적 해법으로 가능해만 제시해 줄 수 있다. 실제 Kanban 시스팀을 사용하는 현장에서는 대부분 경험적으로 초기 Kanban 갯수를 결정한다. 본 논문에서는 현장 경험을 이용하여 각 생산 단계 사이에 생산량, 재고, 고갈이 Kanban 갯수에 따라 관계성을 찾을 수 있다면, 일반 생산 형태를 갖는 Kanban 시스팀에 Kanban 갯수 함수를 적용하여 초기 Kanban 갯수 결정하는 기법을 제시했다.

시표현의 화법분석에 있어서 P-언어의 역할

김복영,박병주,홍지석 홍익대학교 산업디자인 연구소 2004 미술디자인 논문집 Vol.- No.9

The paper aims to ascertain the conditions and rules for the visual expression to produce meaning, as though it were to be an analogical level of linguistics. For this, the researchers needed to analyze the visual artifacts within the context of paradigms and syntagms, with the meta-critical level of visual languages, as a means. As a result, the researchers are ready to propose that there are a system of P-Languages, which play an active part in meta-linguistical level, according to their `morphodynamical principles'. As a fact, the existence of P-Languages could be verified through the analysis of some testing material made under the rigid construction. To scrutinize into the field of visual space, we made use of 〈The Table of Constant and Orbit of Syntagms〉 prepared before for the purpose of our research. The above observation gave an important consequences to our present question. Accordingly, in short, P-Languages seem to produce a series of paradigms and syntagms for the visual expression which, in turn, make conditions and rules of meaningful expression, through their generative and transformational structures which is activated by means of P-Languages for themselves.

장상피화생과 Helicobactor pylori와의 상관 관계에 관한 연구

이복희,김대수,이현숙,진영주,윤세진,송형근,성노현,정현용,이동호 충남대학교 의과대학 지역사회의학연구소 1994 충남의대잡지 Vol.21 No.2

In 1965 Lauren divided advanced gastric carcinoma into two main types-namely, "intestinal" and "diffuse" type carcinoma, which differ not only morphologically but also in their clinical and epidemiological characteristics. Moreover, a different histogenetic process has been postulated by many authors that intestinal type gastric carcinoma might arise from areas with intestinal metaplasia. Since Warren and Marshall reported the presence of Helicobacter pylori in the stomach in 1983, strong evidence has been obtained that there is a close relationship between Helicobacter pylori and chronic gastritis, atrophic gastritis, intestinal metaplasia, and intestinal type gastric carcinoma. To study the relationship between intestinal metaplasia and Helicobacter pylori infection, we performed gastroscopic biopsies and CLO tests taken from patients with epigastric pain. Only 87 patients with macroscopically suspected antral gastritis were included. The prevalence of intestinal metaplasia in gastric antral biopsies increased from 33.3% in the age group<30 years to 63.6% in the age group 60 years. When all patients were divided into two age groups-namely, (i)<50 years(n=41) and (ii)≥ 50 years(n-=46), intestinal metaplasia was found significantly more often in patients ≥ 50 years. ((i) 39.2%, (ii) 54.3%, p<0.0001). The prevalence of Helicobacter pylori in gastric antral biopsies decreased from 66.7% in the age group<30 years to 62.5%, in the age group in the age group 50 to 59 years. When all patients were divided into the same two age groups-namely(i)<50 years and (ii)≥50 years, the prevalence of Helicobacter pylori did not differ between two groups in a statistically significant way. The mean age of intestinal metaplasia positive patients who were also Helicobacter pylori positive was 48±11.0(mean±S.D.)years, whereas the mean age of intestinal metaplasia positive patients who were Helicobacter pylori negative was 52±9.7(mean±S.D.)years. In conclusion. although our data do not prove a causal relationship between Helicobacter pylori infection and the histogenesis of intestinal metaplasia, we suggest that Helicobacter pylori plays an important role in the development of intestinal metaplasia in the gastric mucosa. Whether Helicobacter pylori has to be present at all times during this process or is only necessary as a 'trigger', needs further research.