고온 접촉식 탐상용 초음파 탐촉자 개발 및 평가

김기복,김병극,이승석,윤남원,윤동진,안윤국 한국비파괴검사학회 2003 한국비파괴검사학회지 Vol.23 No.1

고온(500℃) 환경에서 접촉식 탐상이 가능한 초음파 탐촉자를 개발하고 평가하였다. 고온용 탐촉자는 Curie 온도가 600 ℃ 이상인 bismuth titanate 계열의 압전세라믹 소자, 텅스텐 분말과 inorganic binder를 혼합한 후면재, 알루미나 튜브, 전면재, 하우징 등으로 구성되었다. 기본 공진주파수가 각각 1.04 및 2.08 ㎒의 2 종류 탐촉자를 제작하였으며 각종 고온용 커플런트의 온도특성을 시험하였다. 개발된 고온용 탐촉자를 이용하여 강재 시편을 대상으로 시편에서의 초음파 반사신호를 측정한 결과 시편의 온도가 증가함에 따라 반사신호의 크기는 감소하였다. 고온에서 반복측정 실험결과 500℃에서 연속적인 접촉식 초음파 탐상이 가능한 것으로 나타났다. Piezoelectric ultrasonic transducers for high temperature contact measurement were developed. These high temperature ultrasonic transducers (HTUT) consisted of bismuth titanate piezoceramic element whose Curie temperature is higher than 600℃, a backing material of the mixture of tungsten powder and inorganic binder, an inner alumina tube, a wear plate and a housing. The operational frequencies of the HTUT were 1.04 and 2.08 ㎒, respectively. Various commercially available couplant for high temperature were evaluated and compared. As a couplant for high temperature ultrasonic testing between HTUT and test specimen, gold epoxy was selected. The peak amplitude of pulse-echo signals from steel test specimen decreased with increasing temperature. The operational temperature of the HTUT reached up to 500℃ at which the continuous contact measurement was possible.

자궁내 발육지연이 있는 출생체중 2,500 g 이상인 환아의 주산기 예후에 관한 연구

송태복,조명숙,하진아,윤대석,김철홍,김윤하,최영륜 全南大醫大 2004 전남의대학술지 Vol.40 No.1

교차로에서의 최적 교통 신호주기

尹馥植 弘益大學校 科學技術硏究所 2000 科學技術硏究論文集 Vol.11 No.-

In this paper, we consider the problem of finding the optimal traffic signal cycle in the isolated intersection under the light traffic situation. We first mention briefly the existing signal control methods such as fixed cycle control and adaptive control. Then, we introduce a (deterministic) fluid model without overflow and formulate a mathematical model to find an optimal signal cycle minimizing average delay per unit time. After that, stochastic effects in arriving flow of vehicles are included and another mathematical model is derived. In the second model we try to find a signal cycle minimizing the loss of road capacity. Based on the model we can observe easily the fact that under the light traffic condition, the green time should be kept as short as possible, which seems to be apparent but has been ignored in many real-life traffic signal systems.

除草劑에 依한 복숭아果樹園의 雜草 防除試驗

尹柱敬,崔福衍 全南大學校 農漁村開發硏究所 1977 農業科學技術硏究 Vol.12 No.-

最近 全南地方의 복숭아 果樹園에서 크게 問題視되고 있는 果樹園 雜草의 效率的인 藥劑防除를 爲하여 1976年부터 77年까지 2年에 걸쳐서 Paracol 40 E.C. Paraquat 24.5 E.C. Roundup 41 E.C.를 濃度, 回數, 時期를 달리해 一連의 防除實驗을 實施하였던 바 그 結果를 要約하면 다음과 같다. 1. 圃場實驗 1. 本實驗圃에 發生된 雜草의 種類는 9科 12種이었으며, 그 中 優点雜草는 쑥, 환삼덩굴, 망초, 여뀌, 소리쟁이, 둑새풀이었다. 2. Paracol과 Paraquat는 소리쟁이를 除外한 쑥, 환삼덩굴, 망초, 여뀌, 둑새풀에 對해 아주 優秀한 除草效果를 보여 주었으며, Paracol은 80g/10a, Paraquat는 100g/10a 濃度水準에서 95% 以上의 높은 殺草率을 나타냈다. 3. Roundup은 쑥, 환삼덩굴에 對해 200g/10a 濃度水準에서 95% 以上의 높은 殺草率을 보여 주었으나, 300g/10a 高濃度水準에서의 망초, 여뀌, 소리쟁이, 둑새풀에 對한 殺草率은 名名 73.1%, 81.9%, 70.4%, 58.8%로 Paracol이나 paraquat에 比하여 낮았다. 2. Pot 實驗 1. 藥劑의 撤布時期은 Paracol, Roundup이 다같이 開花期가 84.5%, 84.5%, 82,7%로 幼苗期의 72.1%, 74.3%, 71.5%나 生育盛期의 74.4%, 72.2%, 64.1%에 比해 높았다. 2. 藥劑의 撤布 回數에 따르는 殺草率은 Paracol, Paraquat, Roundup이 다같이 2回 撤布가 75%, 74.6%, 74.3%로 1回 撤布의 62.1%, 63.1%, 63.1%에 比하여 높았다. 3. 藥劑의 濃度, 時期, 回數에 따라 95% 以上의 殺草六을 보여 주었던 處理區 가운데 가장 效率的이라 생각된 區는 Paracol이 開花期에 80g/10a, 1回 撤布區와 幼苗期에 2回 撤布區와 幼苗期에 2回 撤布區였으며, Roundup은 開花期에 300g/10a 1回 撤布區와 幼苗期에 100g/10a 2回 撤布區였다. 끝으로 本 實驗을 遂行하는데 있어 積極的으로 協力해 주신 全北大學校 染 桓承 博士께 忠心으로 感謝를 드린다. Weeding in peach orchard, especially in spring and summer, is one of the most serious problems in Chonnam area. Control trials with several herbicides such as Paracol 40 E.C Paraquat 24.5 E.C and Roundup 41 E.C were carried out on the field as well as with the potted weeds for two years from 1976 to 1977. The results are summarized as follows: A. Field test 1. Weeds in peach orchard of the experimental farm, Chonnam National University were 12 species of 9 families, of which Artemisia oulgaris, Erigeron conadensis Humulus japonicus, Alopeculus aequalis, Rumex crispus and Polygonum hydropiper were the predominant ones. 2. All the weeds but Rumex crispus were effectively controlled by Paracol or Paraquat. Withering ratio of more than 95% was obtained by the application of 80g/10a of Paracol or by 100g/10a of Paraquat. 3. Roundup was proved to be less effective than the other two herbicides in controlling orchard weeds. Even though more than 95% of Artemisia vulgaris and Humulus japonicus could be controlled by 200g/10a, of Roundup only 73.1% of Erigeron eanadensis, 81.9% of Polygonum hydropiper, 70.4% of Rumex crispus, 58.8% of Alopeculus aequalis even by 300g/10a of Roundup. B. Pot test 1. Three kinds of herbicides, Paracol, Paraquat and Roundup were applied at different growing stages; seedling, vigorous vegetative growth, and flower bud formation. The difference in weeding effect among herbicides was not found. However, flower bud formation stage was proved to be the most appropriate time for herbicide application. The highest withering ratio of more than 81% was obtained from the application at flower bud formation stage compared to around 70% from those at other two stages. 2. Double applications of any herbicides resulted in about 75% withering ratios, which were higher than those (about 62%) form single application. 3. Among the treatments resulted in withering ratios of more than 95%, single application at flower bud formation stage or double applications at seeding stage with 80g/10a of Paracol, single application at flower bud formation stage or double applications at seedling stage with 100g/10a of Paraquat, and single application with 300g/10a at flower bud formation stage or double applications at seedling stage with 100g/10a of Roundup were considered as the effecient methods in controlling weeds in Peach orchard.

유아교육기관 교사들의 현직교육에 대한 요구분석

윤복남 啓明專門大學 産業開發硏究所 2000 啓明硏究論叢 Vol.18 No.1

유아교육의 질적 향상을 위해서는 끊임없는 교사들의 연수교육이 필요한데 이것은 이들이 창의적인 전문인이기 때문이다. 이 연구의 목적은 유아교육기관 교사들의 자질향상을 위하여 현직교육의 중요성과 현직교육에 대한 과거 경험과 장래의 욕구를 분석하는 것이었다. 이에 256명의 대구지역의 교사들을 대상으로 설문조사를 실시하였는데 그 결과는 다음과 같다. 대구시내 유치원 교사들은 현직교육에 적어도 연 1회 이상, 1회에 약 10일 이내로 참여하고 있었으며 현직교육 참여에의 주요한 목적은 유치원 현장수업을 개선하고 또한 새로운 교육의 접근법을 알고자 함이었다. 그러나 이들이 현직교육에 참가하는데 당면한 가장 심각한 문제는 현직교육 참가비 충당이었으므로 유아교사의 자질향상을 위해서는 재정지원이 요구된다고 하겠다. 한편 장래 교육을 받고자 하는 요구 또한 매우 강하였으며 이들 대부분은 현장에서 활용할 수 있는 기술 또는 유아교육의 새로운 접근방법을 배우기 원하였다. 한편 이러한 현직교육을 실시하기를 희망하는 기관으로는 대학교/전문대학이나 학회 등이었고 참여하기를 원하는 교육프로그램으로는 미술교육, 음악교육, 레지오 에밀리아 접근법, 프로젝트접근법, 컴퓨터교육 등이었다. Teaching is a creative profession which requires continuous development through in-service training in early childhood education. The purpose of this study is to define the importance of in-service training programs for kindergarten teachers and to design programs that meet their needs. In order to assess kindergarten teachers' previous participation in in-service training programs a questionnaire was developed and two hundred and fifty-six kindergarten teachers in the Taegu area were surveyed with this questionnaire. This survey found that kindergarten teachers participated in in-service training programs more than once a year. These programs which covered new approaches and methods of teaching were less than days in length. The greatest difficulty for teachers to attend was to pay tuition. Therefore government financial support is necessary to improve the quality of teachers as well as the early childhood education field. As a result of this survey it was found that kindergarten teachers have a strong need for future educational growth. They want to attend regular in-service programs to learn new theories and skills which they will apply to the classroom. They want to attend in-service training programs during vacations. Teachers are interested in field trips, workshops and skill training which are provided by early childhood associations, colleges and universities. The specific subject that they want to learn more about are Art Education, Music Education, the Reggio Emilia Approach and Computer Education for young children.

태권도용품 광고가 대학생의 구매행동에 미치는 영향

윤상화,최복현 龍仁大學校 2004 용인대학교 논문집 Vol.22 No.-

This study was intended to identify the effect of advertising for Taekowndo products on college students' purchase behavior. For this purpose, the questionnaire research was conducted for 400 undergraduates enrolled in the department of Taekwondo of 4-year colleges located in Seoul and Kyonggi Province. Of them, 350 college students completed the questionnaire and 324 questionnaires except 26 ones with dishonest responses and some omissions were used for final analysis. One-way ANOVA and co-variate analysis was conducted using Window SPSS/ PC +11.5 Version to investigate the difference in purchase behavior according to demographic characteristics and advertising for Taekwondo products. Based on the findings, the following conclusion was concluded: First, an attempt was made to investigate the difference in purchase behavior of Taekwondo products according to demographic characteristics. As a result, it was found that there was a statistically significant difference in purchase behavior according to academic year(P.<05). On the other hand, It was found that there was no statistically significant difference in the purchase behavior of Taekwondo products according to pocket money. Second, it was found that there was a statistically significant difference in purchase behavior according to the degree of reference to the content of advertising for Taekwondo products, in which academic year, one demographic factor, had a statistically significant effect on the purchase behavior of Taekwondo products(P.<05). It was found that the degree of' reference to the content of advertising for Taekwondo products exercised an influence on college students' purchase of Taekwondo products by about 0.6%. Third, it was found that there was a statistically significant difference in purchase behavior of Taekwondo products according to advertisement media, in which the degree of reference to the content of' advertising for Taekwondo products, and academic year, one demographic factor, had a statistically significant effect on the purchase behavior of Taekwondo products(P.<05). And it was found that the advertising media exercised an influence on college students' purchase of Taekwondo products by about 0.6%. Fourth, it was found that there was no statistically significant difference in the purchase behavior of Taekwondo products according to the factor on which importance was attached at the time of product purchase.

B-ISDN에서의 QOS 파라미터 변환

尹馥植 弘益大學校 科學技術硏究所 1993 科學技術硏究論文集 Vol.3 No.-

There are several QOS(Quality of Service) problems which should be solved in parallel with the technical aspects of ATM network for the successful establishment of B-ISDN. We can summarize them as 3 major problems : QOS parameter identification, QOS mapping, and QOS measurements. In this study, we try to establish the mapping between AAL QOS parameters and ATM layer QOS parameters, which can be identified as NP(Network Performance) parameters. This QOS mapping procedure can be extended up to the highest layer if the precise protocols are given. The QOS mapping procedure for a simplified ATM HDTV service is given to demonstrate the mapping idea.

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.

인터넷 서버의 확률적 분석

尹馥植 弘益大學校 科學技術硏究所 2001 科學技術硏究論文集 Vol.12 No.-

The purpose of this paper is to provide a simple but effective strategy on the expansion of server capacity according to the increase in internet traffic. We model an internet server as an M/M/m/m queueing system and derive an efficient method to compute the loss probability which, in turn, is used as a basis to determine the proper server capacity. The process of estimating the traffic parameter values at each internet server based on log data analysis is also given. All the procedures are numerically demonstrated through the process of analyzing the actual log data collected from the web server of a internet game company.

韓國 엘리뜨의 硏究 : with special references to their recruitment, characteristics, roles, and substitute 그 充員·性格·役割·代役을 中心으로

尹慶宇,申福龍 건국대학교 1978 學術誌 Vol.22 No.1

[1] This article is written to bring light on the problems of Korean elites with special references to their recruitment, characteristics, roles and substitute. The weight of elites which is a product of modern political ideology is heavier than any other sects in developing countries. Whether a new state can maintain both stability and development hinges, to a large extent, on the integration of its political elites. Especially during the transition from traditional polities to a more modern political system, elites play a crucial role. Elite activities determine the speed and effectness with which the polity can move toward national integration and political modernity. [2] The recruitment of elites in developing countries can not be considered apart from the mass. Whatever their fear of the masses, the governmental elites in new nations can not do anything without them. While the elite may be unsymphathetic to mass effort to excercise influence, they do want to mobilize the mass for its goals. In Korean case, history of formation of elites can not be deemed as a long one. It did not date back to before the liberation from Japanese rule, because it was after the liberation that the Korean intellectuals approached to the political problems with ideology. In this respect, early elites were recruited from the returning groups from the foreign refuge. But they had many difficult problems, because that they had not any political foundation in their native country; that they were lack of political training : that it was inevitable for them to divide themselves unwillingly on account of territorial difference for their independent fight ; and that their Western political thought was unfamiliar to masses. Those "heroes of renunciation" ex-pected in vain the closeness between mass and themselves in a minute, therefore they felt another alienation. They also have a desperate fight with weakness of economic foundation. [3] The roles what Korean elites should play can be explained as following : First, they should complete the political integration by solving the conflicts around democracy. From the political view, in Korea where is lack of civilian political tradition, our democratic constitution seems to he a superficial graft. But we have had some deomocratic heritages in our history. The thirst task of the Korean elites is to systematize those heritages as a real ideology. Especially, the fact that we have faced to the communist challenge makers it inevitable. And our democratic education must be accomplished with critique on the Communism. Secondly, it is another task of Korean elites to solve the convicts and to integrate politically through educational activities. National patriotism would he in direct proportion to the ratio of literacy. Therefore it is impossible to impose the educational activities to the educators only, as it were, elites should take a part in educational problems. And it musts be remembered that all intellectual activities should be shaded within context of tradition. Thirdly, Korean elites must have regard to the nationalism. Political, economic and ideological unit of today is nation. The nature of nation is not the objective elements as territory or blood but the subjective one as a "state of mind." Therefore in nationalist movement, the leading elites are indispensible more than in any other gorups. Because national sentiment has high suggestibility. [4] In discussing the problems of elites, we can hardly turn our faces from the military as their substitute. As recently as 1930's military government was identified as the ultimate type of totalitarianism. But military industrialism during and after the WW II promoted their states. As Amos Perlmutter suggested, the army's presence in civilian affairs indicates that the existence of corruption is not expected to disappear in the near future ; that material improvements and ideological perspectives do not match; that traditional institutions are unable to bring about material improvement ; that modernized elites are incapable of establishing political institutions and structures which will sustain the momentum of social mobilization and modernization. The roles which military must play in Korea can be classified to four points : First, technical improvement and constructive business, secondly, application of personnel management and staff function, which they obtained in army services, to civilian affairs after the discharging, thirdly, getting training in citizenship, and lastly, the fact that the military has been the traditional bulwark of anti-communist crusades. But military intervention into the civilian affairs may encounter with dilemmas because that religious groups to not often agree on the military activities : that immoderate investment to the military affairs may make national economy lose its equiliibrium: that military intervention in one country encourages intervention by the armed forces of other countries in their own political systems; and the propensity for a military intervention is likely to decrease with increased social mobilization. [5] The main task of elites in Korea is, in conclusion, to accomplish the political integrity and political development by solving the conflicts remaining under the mass consciousness. For these aims, first, elites should stress the importance of consensus and maximize uniformity, secondly, they should emphasize the interplay of individual and group interests by maximizing the integrative values, which are main coals of elites' role.