폐주불사를 혼입한 콘크리트의 내구성에 관한 연구

김태경,박정호,이정호,이주형,박제선,김연경,윤경구 강원대학교 석재복합신소재제품연구센터 1998 석재연 논문집 Vol.3 No.-

콘크리트 구조물은 자연적인 혹은 인위적인 온도의 상승, 강하로 인하여 동결-융해 작용을 받게 되어 구조물의 성능저하를 야기시킨다. 현대에 들어서면서 콘크리트의 내구특성을 파악하기 위한 연구적 요구가 증가되고 있다. 따라서 폐주물사 콘크리트를 실제 구조물에 적용하기 위해서는 내구특성에 대한 연구가 반드시 이루어져야 한다. 폐주물사를 혼입한 콘크리트의 내구특성을 파악하기 위한 동결-융해 실험은 폐주물사의 잔골재 치환율, 물-시멘트비, AE제 사용 여부를 주요 변수로 하여 실시하였다. 원형공시체를 제작하여, 동결-융해 시험기에 넣어 -18∼4℃로 급속 동결-융해를 진행시키면서 매 23싸이클마다 동탄성계수를 측정하였다. 실험결과 AE제를 첨가했을 때 물-시멘트비가 적을수록, 폐주물사의 치환율이 클수록 전반적으로 강도가 증가하는 것으로 나타났으며, 물-시멘트비가 증가함에 따라, AE제를 사용한 콘크리트가 동결-융해 저항성이 증가하는 것으로 나타났다. 특히 폐주물사 치환율이 50%일 때가 동결-융해 저항성이 가장 좋은 것으로 나타났으며 그 다음으로 25, 0% 순으로 저항성이 좋은 것으로 나타났다. 따라서 폐주물사 콘크리트가 내구성이 우수한 것으로 나타나 폐주물사를 콘크리트에 재활용 할 수 있는 것으로 나타났다. Concrete structures has been deteriorated by the freezing and thawing due to temperature gap. This study was conducted to evaluate durability of concrete which are increasingly demanded recently. Therefore the research of durability must be executed for application of waste foundry sand concrete real structures. Concrete durability properties incorporating waste foundry sand was performed with the variable of W/C ratio, Sand/Waste foundry sand ratio and Air entrainment-Non air entrainment. Cylinder specimens were made and subjected to freezing and thawing cycle at -18℃ and 4℃. Dynamic modulus of elasticity were evaluated as F/T cycle increase. The results show that strength of concrete is increased the W/C ratio decrease, the Sand/Waste foundry sand ratio increase when the concrete contains AE agent and decreasing W/C ratio and AE concrete makes improved resistance of freezing and thawing improved. Especially, resistance of freezing and thawing is improved by Fine aggregate/Waste foundry sand ratio which is 50%, 25%, 0% in a row. Therefore it is turn out the waste foundry sand could be applied to concrete from the experiment.

브롬화 및 염화아실들의 친핵성 치환반응 : 지방족 할로겐화 아실의 페놀화 반응 메커니즘(1)

金昌培,鄭泰泳,姜京熙 단국대학교 1978 論文集 Vol.12 No.-

Phenolysis rates of chloroacetyl, acetyl, propanoyl, isobutyryl and pivaloyl chlorides were measured in acetonitrile using three different weak nucleophiles, phenol, p-nitrphenol, and p-methoxyphenol. Result from phenolysis of acetyl chloride revealed that (1) the reaction was approximately second order (2) the rate was fastest with p-methoxyphenol, the strongest nucleophile of the three when phenol concentration was below 0.2M. However, at higher concentration phenolysis rates were in the order of p-Methoxyphenol>p-Nitrophenol>Phenol The varying order in reactivity as a function of phenol concentration was explained tentatively due to medium effect. p-Methoxyphenolysis was conducted using five different aliphatic acyl chloride, and their reactivity changes ClCH_2COCl<CH_3COCl≥CH_3CH_2COCl>CH_3)_2CHCOCl>CH_3)_3CCOCl Intervention of acylium lon-pair was considered to be the best reaction scheme, while neutral structure was important for chloroacetyl chloride.

職業의 社會經濟的 屬性과 階級區分

金璟東,崔泰龍 서울대학교 사회과학연구소 1983 社會科學과政策硏究 Vol.5 No.3

정신질환자의 사회적 지지와 자아존중감에 관한 연구

김태숙,오경옥 충남대학교 의과대학 지역사회의학연구소 1994 충남의대잡지 Vol.21 No.1

This study was conducted to determine the relationship between social support and self-esteem of the psychiatric patients. One hundred ninety subjects( 95 psychiatric patients and 95 normals) between the ages of 18 and 65 were included in the study. The psychiatric patients were recruited from outpatient clinic of C university hospital in Taejon city. The normal subjects were residents of Taejon, who have been matched with the psychiatric patients according to age, sex and spouse status. The instruments used for this study were Norbeck Social Support Questionnaire developed by Norbeck, Lindsey and Carrieri, and Rosenberg's Self-esteem Scale. The collected data were analyzed using percentage, x^2-test, t-test, ANOVA, Pearson Correlation Coefficient by SPSS-X. The results of this study were as follows; 1. The score of psychiatric patients was lower than that of normals on social support(total functional support : t==-8.22, p<.001 ; total social support network : t=-7.82, p<.001). 2. The score of psychiatric patients was lower than that of normals on self-esteem (t = -6.55, p<.001). 3. The relative variables influencing the degree of social support of psychiatric patients were birth order(F=2.66, p<.07), normals were sex(F=4.99, p<.05), birth order(F=4.06, p<.05). 4. The relative variables influencing the degree of self-esteem of psychiatric patients were sex(F=6.21, p<.01), age(F=5.07, p<.008), spouse status(F=7.32, p<.008), birth order(F=3.51, p<.03), normals were sex(F=-9.86, p<.002), age(F-4.4, p<.01) 5. The relationship between the degree of social support and self-esteem of psychiatric patients was found to be a positive correlation that was not statistically significant (r =.054, p>.05). 6. The relationship between the degree of social support and self-esteem of normals was found to be a positive correlation (r=.206, p<.02).

반도체 광 증폭기를 광 스위칭 게이트로 이용한 광 셀 압축기 및 역압축기

김광수,박경태,엄진섭,정광원 강원대학교 정보통신연구소 2000 정보통신논문지 Vol.4 No.-

In this paper, we proposed a new type of optical cell compressor and decompressor, which are essential functional modules in TDM or TDM/WDM hybrid photonic ATM switching systems. The proposed structure drastically decreases hardware requried for implementation by using optical feedback loop for optical pulse delay. Also, it is possible to compress and decompress the large capacity of optical pulse stream just with multi-stage serial connection. We did the experiment of single stage 4 bit cell compression and proved availability of the proposed structure as an essential module for switching systems

가야산 국립공원 지역의 현존식생 및 녹지자연도

김준선,김갑태,임경빈 순천대학교 기초과학연구소 1990 基礎科學硏究誌 Vol.1 No.-

가야산 국립공원지역의 현존식생을 파악하기 위하여 식생상관 및 종조성에 의한 식물사회화학적 분석을 통해 식생군집을 분류하였으며 이를 기초로 녹지자연도를 사정하였다. 가야산의 식생은 크게 소나무림과 낙엽활엽수림으로 구성되었으며 구분된 식생군집은 다음과 같다. 1. 소나무 군집 1) 소나무-진달래 하위군집 2) 소나무-조록싸리 하위군집 3) 소나무-조릿대 하위군집 4) 소나무-대사초 하위군집 2. 신갈나무 군집 1) 신갈나무-철쭉군집 a) 전형하위군집 b) 산앵두나무 하위군집 2) 신갈나무-조릿대군집 3) 신갈나무-조록싸리 군집 3. 졸참나무 군집 4. 서어나무-졸참나무 군집 5. 흰참꽃군집 6. 참싸리-억새군집 또한 가야산국립공원지역의 녹지 자연도 등급은 2차림으로 구성된 녹지자연도 7, 8이 93.9%를 차지하였다. To investigate the actual vegetation and the degree of green naturality(DGN) in Gaya Mountain National Park, forest communities were classified by phytosocialogical analysis according to physiognomy Braun-Blanquet methods. Major forest communities were as follows: 1. Pinus densiflora community 1) P. densiflora-Rhododendron mucronulatum subcommunity 2) P. densiflora-Lespedeza maximowiczii subcommunity 3) P. densiflora-Sasa borealis subcommunity 4) P. densiflora-Carex siderosticta subcommunity 2. Quercus mongolica community group 1) Q. mongolica-Rhododendron schlippenbachii community a) Typical subcommunity b) Vaccinium koreanum subcommunity 2) Q. mongolica-Sasa borealis community 3) Q. mongolica-Lespedeza maximowiczii community 3. Quercus serrata community 4. Carpinus laxiflora-Quercus serreata community 5. Rhododendron tschonoskii community 6. Lespedeza crytobotrya-Miscanthus sinensis var. purpurascens community The map of DGN was drawn according to the actual vegetation map. The ratio of DGN 7 and 8 was 93.9% in Gaya Mountain National Park.

RC로 구속된 조적조 벽체의 전단강도에 관한 실험적 연구

성기태,김경태 忠州大學校 2005 한국교통대학교 논문집 Vol.40 No.2

In order to investigate the effect of the height of application point of lateral loads and reinforcing steel bars in walls and columns in improving the seismic behavior of confined concrete block masonry walls, an experimental research program is conducted. A total of four one-half scale specimens are tested under repeated lateral loads. Specimens are tested to failure with increasing maximum lateral drifts while a vertical axial load was applied and maintained constant.The constant vertical axial stresses applied are 0, 0.84 and 1.80MPa, while the amount of reinforcements in horizontal and vertical directions are 0%, 0.08% and 0.18% respectively. Test results obtained for each specimen include cracking patterns, load-deflection data, and strains in reinforcement and walls in critical locations. Analysis of test data showed that above parameters generate a considerable effect on the seismic performance of confined concrete block masonry walls.

임대아파트의 수선 및 장기수선계획업무 프로세스 모델구축에 관한 기초연구

이춘경,정영한,김지현,이상준,박태근 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

The final goal of this study is to propose the process models of repair and long-term maintenance plan for consistency and effectiveness in rental apartments. This models are expected to help managers improve their works and provide a operation guide in repair and long-term maintenance plan. This study developed an AS-IS process model for repair and long-term maintenance plan in rental apartments. To sum up, it would be possible for managers to use the work processes of repair and long-term maintenance plan for their systematic and effective works. Also, it should be possible to make the integrated maintenance management system for managing current situation and measuring the diagnosis.

유사성 계수에 관한 연구

강경식,오영수,나승훈,김태호 명지대학교 공학기술연구소 1992 공학기술연구소 논문집 Vol.7 No.-

본 논문은 재공품 재고를 줄이기 위한 방법으로서 유사성 계수법의 도입에 관하여 서술하였다. 특히 J.R.King의 이론과 Nakornchai의 ROC-2 이론을 비교 하였다. 그 결과로서 ROC-2의 이론은 적은 기계 혹은 부품에서와 같은 시스템에 사용하는 것이 유리하며 또한 기계나 부품의 그룹화가 서로 독립적으로 수렴되지 않아도 된다는 장점이 있다. This paper reprented that work-in-process inventory has been decreased with the application of the similarity coefficient algorithm. Especially, J.R.King's ROC and Nakornchal's ROC-2 algorithm is studied. The analyzed resuits in this paper are as ROC and ROC-2 algorithm have an adventage that it can be used in production system which has many machinary and component and an arbitrary threshold value should be define and many grouping are being performed independently.

임대아파트의 수선비용 관리시스템을 위한 데이터베이스 구축

이춘경,정영한,박태근,김광우,김창덕,김옥규,황영삼,박홍석 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1

It shows that a variety of side effects result from the housing-supply policy focused in quantity. In a rental apartment for the low-income group, a shortage of maintenance cost in facilities become aggravated. The rapid progress of obsolete leads the lessor to the economic loss as well as a baneful influence to national economy. Also, the maintenance skill brings inadequacy by reason of technique development focused on new construction. As a result, the cost which needs for maintenance should get accomplished to application toward economy analysis and attempt considered management and financial affairs. Simultaneously, it should keep and administer a lot of data of maintenance affairs during life cycle in apartment and set up the way for aiding the situation of maintenance process.