실리카흄을 흔입한 고강도 콘크리트 개발

홍창우,김태경,김경진,김성환,김남윤,심도식,이정호,윤청호,백민경,원치문,박제선,이주형,정경일 강원대학교 석재복합신소재제품연구센터 1996 석재연 논문집 Vol.1 No.-

콘크리트 구조물이 대형화됨에 따라 설계단면이 증대되어 상대적으로 많은 경제적 손실을 부담하게 된다. 따라서 단면을 감소시키면서도 소요의 하중에 안전한 구조물을 건설하기 위해서는 우선적으로 구조물 건설에 기초가 되는 고품질, 고내구성의 고강도 콘크리트 개발이 절실히 요구된다 본 연구에서는 일정 시멘트비 및 혼화재 비율하에서 소요의 워커빌리티가 확보되는 고강도 콘크리트를 시간과 온도의 변화에 따라 증기 양생하여, 압축, 인장, 휨강도 뿐만 아니라 파괴특성을 실험적으로 연구하였다. 시료 제작시 시멘트 입자 사이의 공극 및 불연속 영역을 충전하여 고밀도화하기 위한 콘크리트용 혼화재로 시멘트 비표면적이 상당히 작은 초미립 분말인 실리카흄을 이용하였다. 또한 AE감수제 및 고성능 유동화제를 사용하여 혼화재의 첨가에 의하여 발생될 수 있는 워커빌리티의 감소를 방지하였다. 실험결과에 의하면 일정 양생 지속 시간하에서 온도의 증가에 따라 콘크리트의 압축, 인장 및 휨강도가 전반적으로 증가하였다. 동일하게 일정 온도하에서 양생 지속시간이 커짐에 따라 강도들이 증가됨을 알 수 있었다. 따라서 상대적으로 높은 온도와 긴 지속 양생 조건하에서 파괴에 대한 저항력이 크게 나타났다. The compressible, tensible, and flexibleresistance of the high strength concrete is analyzed by the experimentation in the present study. For the test, we cure several samples with the silica fume as a mixture being become dense the spaces between the particle of cement under the variation of both the temperature and the curing-interval. Then, the superplasticizer and the ezcon are also used to satisfy the required workability for construction. The compressible, tensible, and flexible resistances to a stress are increased as increasing the temperature and the time interval for the curing. Therefore it is concluded that the overal fractural and mechanical properties is improved by mixing the silica fume into the cement.

아프리카 軍隊와 政治(基二)

尹慶宇 건국대학교 1973 法經論叢 Vol.1973 No.8

아프리카 一黨制에 관한 硏究

尹慶宇 건국대학교 1975 學術誌 Vol.19 No.1

The African one-party systems have been developed under the historical situations distinguishable from the single-party systems of Communist and Fascist countries. It may be nearly impossible to include all of the African one-party systems into the same category. The African one-parley systems are able to be divided into three patterns of mono-party system and hegemonical-party system and dominant-party system. In other words, the African one-party systems can be classified into a pragmatic, plural one-party system and a revolutionary, centralized one-party system. However, all of party leaderships are fallen in the hands of one party. The African political parties have the general characteristics to take a active part as a representative of state. The African one-party systems formed on the process of establishment of the African states have been the institutional measures toward a sublime purposes for establishing the African independence and nationalism. The African present situations have demanded the powerful leaderships as a simultaneity of political, economic, social, cultural developments. The political leaders in Africa are absolutely interested in one party democracy assuming the African cercumstances. Therefore, even though parliamentary democracy assuming two-party and mult-party system has been regarded as one of the best political system on the views of a system of western thought, referring to African present situations, the African leaders has not always considered the parliamentary democracy as one of the best political system. They have not counted theirself dictates but regarded their activities as accomplishing states functions on supports of the majority of people through integration of the broken up energy. The African political parties have been formed as a system for integration of tribes and social stratification. I should point out, finally, that some observers hold that use of the term "authoritarian" in analysing African one party systems may not be appropriate, especially where mass type parties are concerned, given the large scale participation provided by buck parties, their role in national integration. The one-party structure is interim system of African states which they are maintaining for the present.

政治資金의 腐敗性과 그 合理性 問題

尹慶宇 건국대학교 1968 學術誌 Vol.9 No.1

The problem of corruption in political affairs represents one of the dilemmas modern states alike harbor, and accordingly to prevent political corruption constitutes one of the important tasks which modem states, whether they like or not, cannot but tackle. Though political fund is often ornamentally expressed to be "the cost of democracy", it has, in the case of our country, been utilized in a wrung way as medium whereby to seek for reflexive benefits in wicked collaboration with forces of political privileges, thus always causing injustice and arousing suspicion. In a hope to wipe out such an unpleasant atmosphere of Korean politics so that we may see politics being conducted fairly under the open surveillance of the populace, I intend in this article to look into the relationship between the political fund and phenomena of corruption and to examine the problem of how political fund can be rationally managed. The matters I handle are as follows : a. Open system of party finance. b. Adjustment of party organization. c. The problem of revising election districts. d. Ethicization of big business. e. The educational-sociological tack of politics.

담도에 국한되어 증상을 유발한 석회쓸개즙 2 예

윤성우,이지영,하경호,이수경,한나,배효근,박선자 고신대학교 의과대학 2010 고신대학교 의과대학 학술지 Vol.25 No.2

Limy bile is a rare condition characterized by excessive precipitation of calcium carbonate in the gallbladder or bile duct. Recently we experienced two cases with obstructive jaundice in which limy bile in the common bile duct but not in the gallbladder for one case, and in the common bile duct and intra hepatic duct but not in the gallbladder for another case. The patients were treated by endoscopic sphincterotomy. Here, we report the cases and review the literature.

Interleukin-1β에 의한 사람 정상 코점막 상피세포의 분비기능 및 형태 변화

김경수,윤주헌,최진우,이정권,문형진,박준호,전희선 대한이비인후과학회 1999 대한이비인후과학회지 두경부외과학 Vol.42 No.11

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.

아프리카 軍隊와 政治(其一)

尹慶宇 건국대학교 1973 敎授論壇 Vol.2 No.1

운동시의 습관적인 이 악물기가 치경부 수복물에 가해지는 스트레스를 분산하기 위한 마우스가드의 사용

윤성영,송창규,박세희,김진우,조경모 大韓齒科保存學會 2010 Restorative Dentistry & Endodontics Vol.35 No.1

마우스가드는 19세기 복싱선수들의 구강내 열상과 연조직의 외상을 막기 위해 사용되었다. 최근에는 치과영역에서 다양하게 사용되고 있으며, 운동 보호 장치, 미백용 장치물, 교정용 유지 장치, 수술용 가이드 장치, 턱관절 안정 장치물 등에 쓰이고 있다. 습관적인 이 악물기에 의한 반복적인 5급 수복물의 탈락은 우선 이 악물기에 의한 스트레스를 조절한 후 수복이 이루어져야 한다. 마우스가드는 이 악물기에 의한 스트레스를 조절하는 장치물로 사용할 수 있다. 본 증례에서는 마우스가드로 치아에 가해지는 스트레스는 감소시키는 것에 대해 논의 할 것이다. 마우스가드를 사용함으로써 반복적인 탈락을 나타내는 5급 수복물의 유지에 단기적으로 만족스러운 결과를 얻을 수 있었다. 만약 환자 및 치과의사가 이 악물기로 반복적인 탈락을 나타내는 수복물로 고생하고 있다면, 마우스가드의 보조적인 사용이 치경부 수복물의 유지에 도움을 줄 수 있을 것이다. Mouthguards were used to protect boxers from lip lacerations and other soft tissue injuries in the late 19th century. Now they are used various parts of dental treatment, which are sports protective aid, bleaching tray, orthodontic retainer, implant insertion guide tray, splint and so on. Repeated dislodgement of Class V restoration due to habitual clenching stress should be restored with stress control. Mouthguard can be used as stress relief device. This case describes methods that can relieve occlusal force to teeth by using mouthguard. Satisfactory results can be obtained by using mouthguard for retention of repeated dislodgement Class V restorations. If patients suffered from repeated restorations of Class V due to clenching, mouthguard can be used additional device to relieve the occlusal stress in conservative dentistry.

상아질 표면 젖음성이 수종 자가접착레진시멘트의 인장접착강도에 미치는 영향

윤성영,박세희,김진우,조경모 대한치과보존학회 2009 Restorative Dentistry & Endodontics Vol.34 No.2

본 연구의 목적은 다른 표면 젖음성을 갖는 상아질에 대한 수종의 자가접착레진시멘트의 인장접착강도를 비교하고자 하는 것이다. 이번 실험을 위해 Rely-X Unicem (3M. ESPE. St. Paul. MN. USA). Embrace Wetbond (Pulpdent. Oakland. MA. USA). Maxcem (Kerr. Orangc. CA. USA) 3종의 자가접착레진시멘트를 사용하였다. 발거한 상, 하악 대구치 60 개를 미세절단기 (Acutom P-50, Struers, Copenhagen Denmark)를 이용해 한 치아에서 2 mm × 2 mm × 7 mm의 치아 시편 두개씩 얻었다. 상아질 표면을 건조 그룹은 10 초간 강한 공기로 건조시켰고, 습윤 그룹은 과잉의 수분을 2 초간 거즈로 압박해 제거하였다. 상아질 표면의 젖음성을 달리한 시편에 자가접착레진시멘트를 접착한 후 상온의 상대습도 100% 상태에서 24 시간 보관했고, 만능시험기 (EZ Test, Shimadzu corporation, Kyoto, Japan)를 이용해 인장접착강도를 측정했고, 분리된 접착면의 파절양상을 근관 치료용 현미경 (OPMI pro. Carl Zeiss. Oberkochen. Germany)을 이용해 20 배의 배율로 관찰하였다. SPSS™ Ver 10.0 (SPSS Inc.. Chicago. IL. USA)을 사용응하여 동일한 자가접착레진시멘트에서 상아질 젖음성에 따른 인장접착강도를 T-test로 비교하였으며, 각 자가접착레진시멘트간의 인장접착강도를 One way ANOVA test로 비교 분석하고 95% 유의수준에서 Scheffe's test로 사후검정 하였다. 실험 결과 자가접착레진시멘트의 인장접착강도는 상마질 젖음성에 영향을 받지 않았으며, 상아질 표면 젖음성과 상관없이 Maxcem의 인장접착강도가 Unicem과 Embrace의 인장접착강도보다 유의성 있는 낮은 값을 나타내었다. 또한 모든 시편의 분리된 접착면은 접착실패 양상을 나타내었다. 이상의 실험 결과로 볼 때 자가접착레진시멘트는 상아질 표면 젖음성에 상관없이 사용할 수 있을 것이라고 생각된다. The purpose of this study was to compare the tensile bond strength of several self-adhesive resin cements bonded to dentin surfaces with different wet conditions. Three self-adhesive resin cements:Rely-X Unicem (3M ESPE. St. Paul, MN USA). Embrace Wetbond (Pulpdent. Oakland. MA, USA). Maxcem (Kerr. Orange, CA USA) were used. Extracted sixty human molars were used. Each self-adhesive resin cement was adhered to the dentin specimens (two rectangular sticks from each molar) in different wet conditions. Tensile bond strength were measured using universal testing machine (EZ Test Shimadzu corporation Kyoto. Japan) at a crosshead speed of 1.0mm/min. After the testing bonding failures of specimens were observed by Operative microscope (OPMI pro. Carl Zeiss, Oberkochen, Germany). T-test was used to evaluate the effect of dentin surface wetness. One-way ANOVA test was used to evaluate the tensile bond strength of self-adhesive resin cements in the same condition. Scheffe's test was used for statistical analyzing at the 95% level of confidence. The result showed that wetness of dentin surface didn't affect tensile bond strength of self0adhesive resin cements and Maxcem showed the lowest tensile bond strength.