• 제목/요약/키워드: Square-Like

검색결과 479건 처리시간 0.026초

미캐니컬 씰의 안전운용 감시를 위한 최적 계측인자 (Optimum Monitoring Parameters for the Safety of Mechanical Seals)

  • Soon-Jae Lim;Man-Yong Choi
    • 한국안전학회지
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    • 제12권4호
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    • pp.214-219
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    • 1997
  • 미캐니컬 씰은 회전축에 장착되는 밀봉장치의 하나로써 많은 산업 현장에서 사용되고 있다. 산업발전과 더불어 미캐니컬 씰의 고장 즉, 밀봉장치에서의 누설, 크랙, 파손, 과대마멸 등과 같은 이상 상태는 대규모 공장의 생산라인을 정지시키거나 심각한 환경오염을 유발시키는 등 경제, 사회적 문제를 야기시키고 있다. 미캐니컬 씰 밀봉면의 미끄럼 운동상태를 인지하고, 미캐니컬 씰의 고장에 대한 감시인자를 도출하기 위하여 미끄럼 마멸실험을 수행하였다. 미캐니컬 씰의 회전속도를 1750 rpm 으로 하여, 매 10 분 마다 미캐니컬 씰 밀봉면의 마멸상태를 광학현미경으로 관찰하였고, 실험동안에 미캐니컬 씰의 미끄럼 운동면에서의 음향방출(AE : Acoustic Emission), 토크, 온도, 등을 측정하였으며, 실시간으로 토크 신호의 주파수 분석을 실시하였다. 각 실험의 초기를 제외하고는 전 구간에서 음향방출 신호의 크기와 토크 값의 변화 경향이 대체로 유사한 경향을 보였다. 정상상태에서는 음향방출, 토크 및 온도가 안정된 상태를 유지하였으나, 이상상태에서는 음향방출의 크기와 토크값이 안정된 상태를 유지하지 못하였으며, 온도는 이상상태 때 급상승하는 경향을 보였다. 토크 값과 온도의 변화가 미캐니컬 씰의 고장에 대한 장기적 감시인자로 적절하다고 생각되며, 미캐니컬 씰의 순간적인 이상상태를 확인하거나 미캐니컬 씰의 운동상태를 인지하는 데는 실효치 전압 상태의 음향방출 신호가 적당하다고 생각된다. 온도는 이상상태 감시 시스템에서 시스템의 신뢰도를 증진시키는 병렬요소로써 활용될 수 있을 것이다.장 큰 결합활성도(binding activity)를 나타내며, 또한 Hyphantria cunea와 같은 나비목의 다른 종의 lipophorin도 인식하는 것으로 나타났다. 따라서 리포포린에 결합하는 수용체의 구조적 또는 기능적 요소는 같은 목내의 종간에 보존되는 것으로 생각된다.과 성충의 생존율은 온도에 따른 계통간 차이는 없었다. 내적자연증가율( $r_{m}$ )은 S계통이 $R_{L}$, $R_{F}$계통보다 $25^{\circ}C$에서는 낮았지만 2$0^{\circ}C$와 3$0^{\circ}C$에서는 높았다. 특히 3$0^{\circ}C$에서는 S계통이 현저히 높았다. 결론적으로 dicofol 저항성계통( $R_{L}$, $R_{F}$)은 저온(2$0^{\circ}C$)과 고온(3$0^{\circ}C$)에서 감수성계통에 비해 생물학적 적응력이 떨어질 것으로 생각된다.력이 떨어질 것으로 생각된다.력이 떨어질 것으로 생각된다.해도 될 것이다. 쐐기 투과율을 정하는 위치가 d$_{max}$ 나 공기중이라면 민조사변에 대한 출력계수를 적용할 수 있지만 다른 깊이에서는 쐐기필터 각각에 대한 출력계수를 또는 조사면크기에 따른 쐐기투과율을 적용해야 할 것이다. 39.2%가 이유 설명 후 사주지 않는 것으로 나타났으며 23.2%가 다음으로 미룬다, 무조건

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Teratoma Formation in Immunocompetent Mice After Syngeneic and Allogeneic Implantation of Germline Capable Mouse Embryonic Stem Cells

  • Aldahmash, Abdullah;Atteya, Muhammad;Elsafadi, Mona;Al-Nbaheen, May;Al-Mubarak, Husain Adel;Vishnubalaji, Radhakrishnan;Al-Roalle, Ali;Al-Harbi, Suzan;Manikandan, Muthurangan;Matthaei, Klaus Ingo;Mahmood, Amer
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권10호
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    • pp.5705-5711
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    • 2013
  • Background: Embryonic stem cells (ESCs) have the potential to form teratomas when implanted into immunodeficient mice, but data in immunocompetent mice are limited. We therefore investigated teratoma formation after implantation of three different mouse ESC (mESC) lines into immunocompetent mice. Materials and Methods: BALB/c mice were injected with three highly germline competent mESCs (129Sv, BALB/c and C57BL/6) subcutaneously or under the kidney capsule. After 4 weeks, mice were euthanized and examined histologically for teratoma development. The incidence, size and composition of teratomas were compared using Pearson Chi-square, t-test for dependent variables, one-way analysis of variance and the nonparametric Kruskal-Wallis analysis of variance and median test. Results: Teratomas developed from all three cell lines. The incidence of formation was significantly higher under the kidney capsule compared to subcutaneous site and occurred in both allogeneic and syngeneic mice. Overall, the size of teratoma was largest with the 129Sv cell line and under the kidney capsule. Diverse embryonic stem cell-derived tissues, belonging to the three embryonic germ layers, were encountered, reflecting the pluripotency of embryonic stem cells. Most commonly represented tissues were nervous tissue, keratinizing stratified squamous epithelium (ectoderm), smooth muscle, striated muscle, cartilage, bone (mesoderm), and glandular tissue in the form of gut- and respiratory-like epithelia (endoderm). Conclusions: ESCs can form teratomas in immunocompetent mice and, therefore, removal of undifferentiated ESC is a pre-requisite for a safe use of ESC in cell-based therapies. In addition the genetic relationship of the origin of the cell lines to the ability to transplant plays a major role.

Clinicopathological Significance of Lymphangiogenesis and Tumor Lymphovascular Invasion in Indonesian Breast Cancers

  • Widodo, Irianiwati;Ferronika, Paranita;Harijadi, Ahmad;Triningsih, F.X. Ediati;Utoro, Totok;Soeripto, Soeripto
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권2호
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    • pp.997-1001
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    • 2013
  • Background: Lymphangiogenesis, assessed as lymphovascular density (LVD), is the initial step of generalized tumor lymphovascular invasion (LVI). It also involves VEGF-C as the most important protein family. Lymphangiogenesis among breast cancer cases correlations with several clinicopathological factors are important to determine prognosis and treatment strategies, but results have been controversial and require clarification. Aim: To define correlations between VEGF-C expression, LVD and LVI with several clinicopathological parameters from Indonesian breast cancer patients. Materials and Methods: Using a cross-sectional study, a total of 48 paraffin-embedded tissues of breast cancer from Dr. Sardjito General Hospital Indonesia were assessed for VEGF-C expression, LVD and LVI by immunohistochemistry. Correlations of these markers with clinicopathological parameters like patient age, tumor size, lymph node status, grade, ER/PR and Her-2 status, cell proliferation and p-53 expression were investigated by linear analysis. Correlations of VEGF-C expression and LVI with several clinicopathological parameters were analyzed with Coefficient Contingency Chi-Square test. Results: The mean of patients age was 53.0 year, pre and post-menopausal patients accounting for 56.3% and 43.8%, respectively. Some 10.4% were well, 41.7% moderate and 47.9% poorly differentiated. ER positivity was evident in 50% while PR and Her-2 positivity was found in 31.3% and 33.3%, respectively. Breast cancer cells with over-expression of p-53 was 64.6% and with high cell proliferation was 56.3%. Lymph node metastasis was noted in 63.5%, and LVI in 72.9%. Significant correlations were found between LVD and tumor size (p:0.037), grade (p:0.000), lymphnode status (p:0.036), LVI (p:0.003), as well as with p-53 and cell proliferation. There were also significant correlation of VEGF-C (p:0.011) and LVI (p:0.001) with tumor grade. Only ER status was found to have a correlation with tumor size (p:0.027). Conclusions: This study suggested that in Indonesian breast cancer patients, lymphangiogenesis is correlated with tumor size, grade, lymph node status and tumor lymphovascular invasion, the latter also being related with p-53 over expression and high cell proliferation.

고가(高架)구조물의 정위치 시공을 위한 준스태틱RTK 측위의 적용성 실험 (Availability Evaluation of Quasi Static RTK Positioning for Construction of High Rise Buildings and Civil Structures)

  • 김인섭
    • 대한공간정보학회지
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    • 제19권4호
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    • pp.119-126
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    • 2011
  • 초고층 건물이나 고가 구조물 상부의 정위치 측설에 주로 사용되어 왔던 광학식 TS장비는 시준선 확보의 어려움, 장거리 관측에 따른 오차의 증가 및 동적관측의 어려움 등으로 인하여 사용성이 많이 떨어지므로 최근에는 GPS를 이용한 측량방법이 제시되고 있다. 그러나 기존의 GPS측량방법들은 대부분 후처리 방법으로서 측설, 검측, 위치조정 및 확인측량 등 일련의 과정에서 시간이 과다 소요되는 문제점이 있다. 따라서 본 논문에서는 RTK측위 기법을 적용하여 실시간으로 구조물의 위치를 검측하고 조정함으로써 측량으로 인한 공사의 중단을 최소화 하고, 준스태틱 RTK기법에 의한 고정밀의 측정값을 기반으로 망조정을 통해 수 mm 이내의 높은 정확도로 시공좌표를 결정함으로써 공정관리와 품질관리를 모두 충족시킬 수 있는 방법에 대해 실험 하였다. 실험결과 130m 이상 높이의 고가 구조물 상층부에서 사변망을 이루는 4점의 준스태틱 RTK 관측점을 최소제곱법으로 망조정 하면 약 2mm 내외의 정확도로 구조물 측설이 가능하므로 향후 초고층 건물이나 고가 교량등의 시공측량에 널리 적용될 수 있을 것으로 사료된다.

Development of Life Test Equipment with Real Time Monitoring System for Butterfly Valves

  • Lee, Gi-Chun;Choi, Byung-Oh;Lee, Young-Bum;Park, Jong-Won;Nam, Tae-Yeon;Song, Keun-Won
    • International Journal of Fluid Machinery and Systems
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    • 제10권1호
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    • pp.40-46
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    • 2017
  • Small valves including ball valves, gate valves and butterfly valves have been adopted in the fields of steam power generation, petrochemical industry, carriers, and oil tankers. Butterfly valves have normally been applied to fields where in narrow places installing the existing valves such as gate valves and ball valves have proven difficult due to the surrounding area and the heavier of these valves. Butterfly valves are used to control the mass flow of the piping system under low pressure by rotating the circular disk installed inside. The butterfly valve is benefitted by having simpler structure in which the flow is controlled by rotating the disc circular plate along the center axis, whereas the weight of the valve is light compared to the gate valve and ball valve above-mentioned, as there is no additional bracket supporting the valve body. The manufacturing company needs to acquire the performance and life test equipment, in the case of adopting the improving factors to detect leakage and damage on the seat of the valve disc. However, small companies, which are manufacturing the industrial valves, normally sell their products without the life test, which is the reliability test and environment test, because of financial and manpower problems. Furthermore, the failure mode analysis of the products failed in the field is likewise problematic as there is no system collecting the failure data on sites for analyzing the failures of valves. The analyzing and researching process is not arranged systematically because of the financial problem. Therefore this study firstly tried to obtain information about the failure data from the sites, analyzed the failure mode based on the field data collected from the customers, and then obtained field data using measuring equipment. Secondly, we designed and manufactured the performance and life test equipment which also have the real time monitoring system with the naked eye for the butterfly valves. The concept of this equipment can also be adopted by other valves, such as the ball valve, gate valve, and various others. It can be applied to variously sized valves, ranging from 25 mm to large sized valves exceeding 3000 mm. Finally, this study carries out the life test with square wave pressure, using performance and life test equipment. The performance found out that the failures from the real time monitoring system were good. The results of this study can be expanded to the other valves like ball valves, gate valves, and control valves to find out the failure mode using the real time monitoring system for durability and performance tests.

경기지역 노인의 건강과 식생활관리 II - 75세 미만의 젊은 노인과 75세 이상 고령 노인 비교 - (The Elderly Health and Dietary Management in Gyeonggi Province II - Comparison with Younger Old and Older Old -)

  • 이승교;최미용;원향례
    • 한국지역사회생활과학회지
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    • 제17권1호
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    • pp.141-154
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    • 2006
  • The purpose of this study is to provide the information of the aged olds for which basic data are almost no available. The subjects were divided on the base of age 75. The elderly under 75 were named 'the young olds' and over 75 were 'the aged olds'. The aim of this research is to promote health and to improve nutrition, and the survey was made for health promotion behaviors, habits against health risk, dietary management status and diet intake. And it was conducted by 24 hr-recall method and analyzed by nutrients intake. 242 subjects were collected in 12 cities or counties in Gyeonggi Province and 20 elderly people (10 male and 10 female) were selected out of 1 village in each district. Questionnaire about health behavior and dietary management was carried out by interview method through regional home extension workers. Statistical analyses were made by SAS (version 8.1) and Chi-square tests and General Linear Models were used. Out of the subjects the aged olds over 75 was 31.9%, elementary school educated (93.5%), with spouse (40.3%), with adult children(28.6%), monthly living cost of 500-1,000 thousand won(40.3%). Mean age was 78.82 years compared with 69.75 years of the young olds. 46.8% of the aged olds used monthly pocket money over 1000 won and it was lower than 63.3% of the young olds. Only half of the aged olds had regular exercise of walking (77.8%) or with athletic equipment (17.8%). However, the young olds did more frequent walking (82.1 %) and less exercise with athletic equipment (4.8 %), which was significantly different. Kinds of disease were different with the young or the aged olds, as more proportion of cardiovascular disease(37.9%) for the young olds and joint lumbago neuralgia(41.6%) for the aged olds. Dietary management was good (3 meals per day: 93.4%, fixed mealtime: 72.4%, and regular amount: 79.9%). But there was significant difference in side dish varieties and kinds of snacks; for the aged olds only 8% had over 5 sorts (compared with 18.8% of the young olds) and the kinds of snacks were cookie, candy, juice, carbonated beverage for the aged olds (compared with noodle, milk, soybean-milk for young olds). The ratio of nutrients intake (energy, riboflavin and niacin) with RDA was significantly higher for the aged olds than that of the young olds. The surveyed subjects had no difficulties in Activities of Daily Living (ADL), but some of the aged olds had difficulties in Instrumental Activities of Daily Living (IADL) like housekeeping, using transportation, going shopping and making phone calls. These results suggest that low quality of life is linked with low economic status of the rural elderly and congregate meal at village hall would be required because of the lack of side dishes variety for the aged olds. And nutrition education program about good snacks and exercise practice would be needed for the aged olds. By operating nutrition education program the aged olds would enjoy better quality life maintaining or ameliorating IADL abilities.

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경기지역 노인의 건강과 식생활관리 I - 노인의 성별 비교 - (The Elderly Health and Dietary Management in Gyeonggi Province - Comparison with Gender Difference -)

  • 원향례;이승교;최미용
    • 한국지역사회생활과학회지
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    • 제17권1호
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    • pp.123-139
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    • 2006
  • The purpose of this study is to search how to promote health and improve nutrition and health care of the elderly people in rural area. Behaviors for health promotion and habits against health risk were surveyed. Dietary management was analyzed for surveyed nutrient intake by 24 hr -recall method. 242 subjects were collected in 12 cities or counties in Gyeonggi Province and 20 elderly people (10 male and 10 female) were selected out of 1 village in each district. Questionnaire for health behavior and dietary management was carried out by trained interviewers. Statistical analyses were made by SAS (version 8.1) and Chi-square tests and General Linear Models were used. Characteristics of the elderly people were 61-74 year-olds (68.2%), elementary school educated (78.4%), with spouse (51.7%), monthly living cost of 500-1,000 thousand won(43.4%), and monthly pocket money of 50-100 or 100-200 thousand won(33.5%, 26.5%). 41.4% of the subjects checked up medical examination regularly. The alcohol drinking status was significantly different according to gender: high no-drink rate of female (52.5%) and low no-drink rate of male (25.6%). Kinds of disease were different according to gender: higher proportion of cardiovascular disease(46.3%) and diabetes mellitus(8.1 %) in male and joint lumbago neuralgia(44.4%) and osteoporosis(8.6%) in female. Gastrointestinal complaints were nausea (69.0%) and chronic indigestion (17.8%). Constipation (12.0%) and vomiting (4.3%) were more frequent in female. Dietary management was good (3 meals per day: 93.4%., dining with family: 72.4%, regular mealtime: 72.4%, and 3-4 times of snacks per week: 44.9%) except side dish taking of 3-4 kinds only. However, almost one-third of the female elderly ate alone (30.6%) which was well compared with one-fifth of the male (19.7%). And food and nutrients intake were not significantly different according to gender except that male elderly's intake of energy and protein was lower than that of female's. The surveyed subjects had no difficulties in Activities of Daily Living (ADL), but some female elderly had some difficulties with Instrumental Activities of Daily Living (IADL) like working at home, using transport, and going shopping. These results suggest that low quality of life linked with low economic status of the rural elderly and that congregate meal at village hall would be required for the female elderly eating alone. For the undernourished male elderly, it would be needed to provide snacks and to establish nutrition and health surveillance system.

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Effects of Synchronization of Energy and Nitrogen Release in the Rumen on the Starch Disappearance in the Gastrointestinal Tract and Growth Performance of Hanwoo Steers

  • Li, Dong-Hua;Oh, Young-Kyoon;Lee, Sang-Rak;Choi, Seong-Ho;Un, Ok-Ji;Seol, Yong-Joo;Nho, Whan-Gook;Moon, Sang-Ho;Kim, Kyoung-Hoon
    • Journal of Animal Science and Technology
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    • 제53권6호
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    • pp.533-540
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    • 2011
  • The objectives of experiments were to compare directly the effects of synchrony of slowly fermented (corn and corn gluten meal; C-CGM) and of rapidly fermented ingredients (barley and soybean meal; B-SBM) in the rumen on starch disappearances in gastrointestinal tracts (Experiment 1) and growth performance (Experiment 2) of Hanwoo steers in the feedlot barn. In experiment 1, four Hanwoo steers ($288{\pm}21$ kg) fitted with ruminal and "T" shaped duodenal cannula were placed in one pen with Calan gate and assigned randomly to a duplicate $2{\times}2$ Latin square design. In experiment 2, eight intact Hanwoo steers ($311{\pm}8$ kg) were assigned randomly to one of two pens with Calan gate to evaluate the effect of the same diets as like in experiment 1 on growth performance. There were no differences in ruminal pH, ammonia and total VFA concentrations between treatments. Percentage of apparent ruminal starch disappearance was 33.3% unit lower (p<0.05) for steers fed C-CGM than for steers fed B-SBM diets and this difference resulted in 268% higher (p<0.05) in duodenal starch flows for steers fed C-CGM diet than for steers fed B-SMB diet. There was significant increase (p<0.05) in quantity (927 vs. 400 g/d) of corn starch digested post-ruminally compared to barley starch. However, percentage of starch apparently digested post-ruminally was 8% higher (p=0.1) in steers fed fast synchrony diet with B-SBM than in steers fed slow synchrony diets with C-CGM. The differences of percentage and amount of starch apparently digested post-ruminally between C-CGM and B-SBM diets did not affect rice straw DM intake, average daily gain (ADG) and feed efficiency. In conclusion, there is some uncertainty in regards to the relationship between site of starch digestion and DM intake, ADG, and feed efficiency in this study.

초등수학영재학급에서 교수자의 지도 목표와 학습자의 학습 목표 인식 간극 분석 (Analysis on the Perception Discrepancy between Teacher's Teaching Goal and Students' Learning Goal in the Elementary School Mathematics Class for the Gifted)

  • 임성재;송상헌
    • 한국초등수학교육학회지
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    • 제19권1호
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    • pp.1-16
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    • 2015
  • 본 연구는 영재학급에서 수업 중 교사가 강조하는 지도 목표와 학생들이 인식하는 학습 목표 도달 정도의 차이를 분석해 봄으로써 영재학급에서의 학습 목표 제시 방식을 개선하는 데 목적이 있다. 이를 위해 초등학교 6학년 2개 학급(각 20명씩 총 40명) 학생들의 활동지를 양적으로 분석하였으며, 각 학급 내 성취 수준이 상, 중, 하위권에서 각 1명씩을 대상으로 수업 중 연구자 참여 관찰과 수업 후 개별 면담을 통해 그들의 학습 목표 인식 사례를 질적으로 분석하였다. 학습 목표는 내용면, 과정면, 태도면에서 각각의 하위 요소별로 교사가 사전에 기술해 놓은 것에 대해 교사 자신이 강조한 정도와 학생이 인식한 정도의 간극을 항목별로 차이를 수치화하여 비교하였다. 연구 결과 영재학급 학생들은 내용면보다는 상대적으로 과정면에서 학습 목표에 대한 인식이 낮음을 알 수 있었는데, 전반적으로 연역적 사고, 유추적 사고, 발전적 사고에 있어서 교사의 강조 정도와 인식 정도의 차이를 보였고 특히 유추적 사고에서 학습 목표에 대한 그 인식 정도가 가장 큰 차이를 보였다. 이를 통해 얻게 된 몇 가지 교육적 시사점을 제시하였다.

이형 하부다이아프램으로 보강된 각형 CFT 기둥-보 접합부의 내진성능에 관한 연구 (A Study on Seismic Performance for CFT Square Column-to-Beam Connections Reinforced with Asymmetric Lower Diaphragms)

  • 최성모;윤여상;김요숙;김진호
    • 한국강구조학회 논문집
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    • 제15권5호통권66호
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    • pp.579-589
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    • 2003
  • 콘크리트충전 강판(CFT)기둥과 H-형강 보 접합부의 기존 보강 방식은 상 하 동일 다이아프램 형태로 처리하는 것이 일반적이지만, 우리나라와 같은 중 약진지역에서는 하부플랜지에 인장 발생률이 적으므로 하부측을 단순화시켜 경제적인 접합부를 만들 수 있다. 우선적으로 본 논문에서는 단순인장실험을 실시하여 인장거동을 파악하고, 그 결과를 확장 적용하여 하부측 단순화의 타당성을 검증하였다. 본 실험에서는 상부에 복합십자형 다이아프램(Combined Diaphragm)을 하부에는 네 가지 형식 즉, 복합십자형, 무보강, 수평 T-bar, 수직 Plate를 다아아프램으로 제작한 실대크기의 실험체를 ANSI/AISC SSPEC-2002 가력 프로그램(AISC,2002)에 따라 반복가력실험을 하였다. 하부다이아프램에 사용된 수평 T-bar와 수직 Flat bar의 스터드 볼트는 횡력에 의해 하부다이아프램에 인장력이 가해질 때 보 플랜지의 인장력을 내부 콘크리트에 전달하기 위함이다. 각각의 실험체는 하부 인장시 내력의 차이가 조금 있었으나 모든 실험체가 AISC에서 규정하고 있는 합성보통모멘트 골조인(AISC,2002) 0.01rad의 비탄성회전 능력을 발휘하였다. 하부 접합부의 거동을 분석한 결과, 단순화된 하부다이아프램은 내력과 강성뿐만 아니라 소성 변형 능력이 우수하며 현장에 사용하기에 충분한 내진성능을 나타냄을 입증하였다.