• 제목/요약/키워드: CM test

검색결과 3,660건 처리시간 0.031초

Double-Punch Test에 의한 콘크리트의 인장강도 시험에 관한 연구 (A Study on Double - Punch Test for Tensile Strength of Concrete)

  • 이우종;고재군
    • 한국농공학회지
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    • 제30권2호
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    • pp.82-94
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    • 1988
  • The purpose of this study is to introduce the Double Punch test method which is an indirect testing method of tensile strength of concrete, and to compare with the tensile strength of concrete as determined by the split-cylinder test, a practical method for performing the Double Punch test to obtain the tensile strength of concrete is proposed and recommended for general use. In this study, the dimensions of cylindrical specimens used in the Double-Punch test were 15X30cm, 15X15cm, 10${\times}$(20cm, and 5${\times}$l0cm, and in the split-cylinder test were 15${\times}$(30cm, 15${\times}$(15cm, and 10${\times}$(20cm. And the diameters of loading punches used in the Double-Punch test were 1.5cm, 2.5cm, and 3.5 cm. The results obtained from tests are summarized as follows ; 1. In the split-cylinder test, the tensile strength of concrete by the linear elasticity theory is similar to that of plasticity theory. 2. Both split-cylinder test and Double-Punch test, tensile strength of concrete is increased with decreasing specimen size. This tendency is identical when the ratio of specimen diameter to height is 1: 2, but that tendency is quite different when the ratio is 1: 3. In the Double-Punch test, if specimen size is constant, by increasing the punch size, tensile strength of concrete is increased, too. 4. Using a 15 ${\times}$( 15 cm cylinder specimen and 3.5 cm diameter punch in the Double Punch test would give the most uniform and consistent result in tensile strength, and the result showed a gQod correlation with splitting tensile strength from 15 x 30cm specimen. 5. In order to obtain satisfactory results and to nuninuze variability, it is proposed that specimens of 15 cm in diameter and 15 cm in height with two 3.5 cm diameter punches should be used. It seems, therefore, reasonable tt) take f't=0.0024 P(kg / cm$^2$) as a working formula for computing the tensile strength in the Double Punch test for concrete.

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유공위치 변경에 따른 RC기둥의 내력변화에 관한 실험적 연구 (Stress Change Varying with Hole Place of RC Column)

  • 손기상
    • 한국안전학회지
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    • 제21권2호
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    • pp.70-79
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    • 2006
  • many plumbing system are needed in the ceiling of the building as it becomes advanced more and more. This leads to make effective space between ceiling level and slab less. Also, piping system is not suitably arranged and operated if it is bent around the columns which they are a lot. But this system can be more effective if it passes through the columns directly. Most people think that those columns should not be damaged with such as holes. But actually this is existed in a hotel building in switzerland. This study is to fing out how much capacity the columns become damaged and low using model size of $20cm{\times}30cm$ rectangular section, and 160cm long, in the structural test. it's compressive strength is focused on $240kg/cm^{2}$ design strength, commonly used in korea. Compressive test for them was done at Hanyang University using UTM one thousand tone(1000t) capacity. Variable numbers for the study are one hole of dia 3cm with distance 20cm or 40cm, two holes of dia 3cm with 20cm and 40cm distance, one hole of dia 5cm with distance 20cm and 40cm, two holes of dia 5cm with 20cm and 40cm distance, me eccentric hole with 20cm and 40cm distance, Normal(without hole). two test specimens of each variable are made for the test. ED5H20 capacity was 16.7% decreased, compared to normal one. While ED5H40 distant 40cm from the end of column top showed 19.5% capacity decrease, compared to normal one. Strain of ED5H20 diameter 5cm, in distance of 20cm form the top of the column was less 5% than the one of diameter 3cm. Finally, conclusions are that in case of hole diameter 3cm, located at 20cm from the end of the column top, capacity was decreased down to 3, percent only compared to the same diameter hole with 20cm distant from the end of it.

의도적인 견갑골 외전이 Sit-and-Reach Test에 미치는 영향 (Effect of a Intentional Scapular Abduction on the Sit-and-Reach Test)

  • 김선엽;지창연;김광수
    • 대한정형도수물리치료학회지
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    • 제6권1호
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    • pp.15-26
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    • 2000
  • Purpose : This study was done to examine the actual effect of the scapular position in these flexibility tests. The purpose of this study was to examine the differences between the measurement of SRT(Sit-and-Reach Test) without intentional abduction of the scapular (pre-test) and with intentional abduction of the scapular (post-test). The hypothesis is: 1. There is no differences in the SRT result of the pre-test and the post-test. 2. There is no differences in the HJA(Hip Joint Angle) result of the pre-test and the post-test. 3. There is no differences in the Spine Motion Test(SMT) result of the pre-test and the post-test. Method : The total 60 people (30 men, 30 women) were participated in this study. In the pre-test, the subjects were asked to sit on the examination table and try the SRT motion; and then the HJA, SRT and the SMT numerical values were taken. In the post-test. the subjects were instructed to intentionally bring the scapula outward from the midline; and the HJA, SRT and the SMT numerical values were taken. Result : In the pre-test. the SRT result averaged 34.17cm. and in the post-test. the SRT result averaged 36.68cm. The difference was about 2.81cm which showed a significant mean statistically (p<0.01). The measurement increased by 8.22%. The HJA was $85.9^{\circ}$ in pre-test, and it was $85.5^{\circ}$ in post-test. giving the $0.4^{\circ}$ differences. Therefore, it didn't have a statistical mean (p>0.05). The SMT value was 69.56cm in the pre-test. and it was 69.28cm in the post-test, about 0.28cm decreased. Therefore, it didn't have a statistical mean (p>0.05). SRT values and HJA values were correlated (p<0.01). SMT values and SRT values (p<0.01), and SMT values and HJA values(p<0.05) were each in counter correlation. Conclusion : The result of the SRT without intentional scapular abduction (34.17cm) and with intentional scapular abduction (36.68cm) showed a significant increase about 8.22% (p<0.01). In SRT, the effect of the intentional scapular abduction on SMT showed no significant means, the pretest value being 69.56cm and the post-test value being 69.28cm (p>0.05).

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Bacillus 발효액 Enzamin의 투여가 인체의 NK세포 활성도와 Hamster의 골밀도에 미치는 탐색연구 (Research on the Bacillus-fermented Enzamin Administration on Human NK Cell Activity and Bone Density of Hamster: A Pilot Study)

  • 류서원;藤井登起男;이형환
    • 한국자연치유학회지
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    • 제7권2호
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    • pp.63-69
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    • 2018
  • 목적: 본 연구는 Bacillus 발효액(ENM)을 섭취한 사람의 NK세포활성도와 Hamster의 골밀도, 골량과 골면적에 미치는 영향을 연구하는 것이 목적이었다. 방법: NK세포 활성도 측정과 x-ray를 통한 골밀도 검사를 하였다. 결과: NK 세포의 활성도는 대조군은 644.71 pg/ml, 임상군이 1796.37 pg/ml로 높게 나타나 유의성이 있었다(p<.004). 그리고 임상군은 섭취 전 검사에서 1110.37 pg/ml, 사후검사에서는 1796.37 pg/ml로 유의성이 있게 증가하였다(p<.001). ENM 먹인 후의 햄스터들의 행동관찰에서는 대조군과 임상군 간의 행동은 차이가 없이 정상적으로 행동하였다. 체중의 변화는 대조군에서는 최초 및 최종 27일째에 측정한 체중은 106 g로 거의 변동이 없었으며, 임상군은 최초 측정이 96.6 g, 최종 27일째는 114 g로 증가하여 유의성이 있었다. 햄스터 뒷다리를 X-선 촬영한 사진에서는 형태적인 변화는 관찰되지 않았다. 대조군의 골밀도는 0.059 g/cm3, 임상군은 평균 골밀도는 0.062 g/cm3로 0.003 g/cm3만큼 증가하였다. 골중량은 대조군은 0.175 g, 임상군은 0.196 g로 증가하였다. 골면적은 대조군은 2.95 cm2, 임상군은 3.14 cm2 으로 0.19 cm2만큼 증가하였다. 부검에서 대조군과 임상군은 모두 특기할만한 이상은 없고, 각 장기도 정상이었다. 결론: ENM 섭취는 NK세포활성도와 Hamster의 골밀도를 증가시키는 유용한 식품이라 생각한다.

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대형삼축압축시험을 이용한 북제주현무암 사석재의 강도정수 산정 (Evaluation of Strength Parameters of North-Cheju Basalt Rubble Using Large-Scale Triaxial Test)

  • 정철민;김종수;채영수
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2002년도 봄 학술발표회 논문집
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    • pp.189-196
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    • 2002
  • According to the Korean Design Code for port and harbor facilaties, bearing capacity of rubble mound under eccentric and inclined load is calculated by the simplified Bishop method, and strength parameters are recommended to be c=0.2kg/$\textrm{cm}^2$ and ø=35$^{\circ}$for standard rubble if the compressive strength of parent rock is greater than 300kg/$\textrm{cm}^2$, quoting from research results by Jun-ichi Mizukami(1991), But this facts have never been certified in Korea because there was not large-scale triaxial test apparatus until 2000 in Korea. Firstly in Korea, the large-scale triaxial test (sample diameter, 30cm and height, 60cm) on the rubble originated from porous basalt rock in North-Cheju was accomplished. Then strength parameters for basalt rubble produced in North-Cheju are recommended to be c=0.3kg/$\textrm{cm}^2$ and ø=36$^{\circ}$if the compressive strength of parent rock is greater than 400kg/$\textrm{cm}^2$.

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정하중 및 동하중이 작용하는 연약지반의 거동특성(비교모형실험) (Characteristic of a Soft Ground Behavior Subjected to Static and Dynamic Loads (A Study on the Model Test))

  • 김종렬;강진태;이치열;박용면;정재훈
    • 한국지반공학회논문집
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    • 제24권1호
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    • pp.111-118
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    • 2008
  • 본 연구에서 준설매립지반과 같은 연약지반의 개량 시 장비의 연행하중이 지반에 미치는 영향을 파악하고자 2차원 모형재하시험을 실시하였다. 정하중 및 동하중은 각각 $0.02kg/cm^2,\;0.03kg/cm^2$$0.04kg/cm^2$으로 압밀된 모형지반에 재하하였다. 압밀하중 $0.02kg/cm^2,\;0.03kg/cm^2$$0.04kg/cm^2$으로 2달간 압밀시킨 후 각각의 압밀하중으로 인한 극한지 지력은 $0.16kg/cm^2,\;0.19kg/cm^2,\;0.24kg/cm^2$인 것을 얻을 수 있었다. 그리고 정하중시험의 침하량과 같아지는 지점의 동하중시험 시 에너지 값은 각각의 압밀하중에 대하여 $E=336{\sim}945kg{\cdot}cm,\;E=252{\sim}780kg{\cdot}cm$$E=323{\sim}727kg{\cdot}cm$의 범위를 나타냈다. 같은 지반조건에서 정하중과 동하중이 각각 작용할 경우, Heaving량은 정하중보다 동하중 작용시 더 컸으며, 수평변위량은 정하중 시험에 비해 극히 미비하게 나타났다.

LP가스 폭발로부터 화재로의 천이에 관한 연구 (A Study on the Explosion to Fire Transition Phenomena of Liquidfied Petroleum Gas)

  • 오규형;이춘하
    • 한국안전학회지
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    • 제8권4호
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    • pp.107-113
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    • 1993
  • Small rectangular explosion chamber of its size 25cmX25cmX32cm with a circular bursting diaphram at the top was used to study the mechanism of gas explosion to fire transition phenomena, the process of ignition of solid combustibles during a gas explosion. To visulize the explosion to fire transition phenomena, transparent acryl window and high speed camera system were used. The test piece of solid combustible in this experiments was a 5cm$\times$5cm square sheet of newspaper which was placed in the explosion chamber filled with a LPG-air mixture. The mixture was ignited by an electric spark at the center of the chamber. Explosion to fire transition phenomena and the behavior of out flow and in flow of gas through the opening yielded by bursting the diaphram was visualized with shlieren system and without shlieren system. Diameter of a bursting dlaphram at the top of the explosion chamber was varied 5cm, 10cm, and 15cm, and the position of test piece were varied with 6 point. Explosion pressure was measured with strain type pressure transducer, and the weight difference of the test piece before and after each experimental run was measured. By comparing the weight difference of solid combustibles before and after the experiment and the behavior of out flow and inflow of gas after explosion, it was found that the possibility of ignition was depends on the LPG-air mixture concentration and the exposure period of test piece to the burnt gas. Test result of this experiments it was found that the main factor of this phenomena are that heat transfer to the test piece, and the pyrolysis reaction of test piece. Based on the results, the mechanism of the explosion to fire transition phenomena were inferred ; gas explosion- heat transfer to solid combustibiles ; pyrolysis reaction of solid combutibles : air inflow ; mixing of the pyroly gas with air ignition.

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비만체형을 위한 신축성 직물 스커트의 여유분에 관한 연구 (A Study on Ease for the Skirt of Stretch Fabric according to the Fat Body Types)

  • 설경희;서미아
    • 복식문화연구
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    • 제10권4호
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    • pp.392-403
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    • 2002
  • The purpose of this study was to make clear reduction ratio due to the stretch ratio and to find out the ease for the patterns of stretch skirt according to fat body type to improve the aesthetics and wearing satisfaction. For this study, three college students were selected according to the fat body types; According to fat body types, 15 experimental skirt which were different each other in terms of the amount of ease on wait and hip, were made for the appearance test and wearing satisfaction test. The results from the study were as follows: 1. The results from the appearance test were as follows. For the ease on waist, W+2cm and W+0cm for fat body type were suggested for the best fit. For the ease on hip, H+2cm and H+0cm for fat body type were suggested for the best fit. 2. The results from wearing satisfaction test were as follows. W+2cm, H+2cm for fat body type were suggested for the best wearing satisfaction. 3. Based on the results from the above tests, the pattern reduction ratios for stretch skirt were as follows. pattern reduction ratio 0∼2.4% of waist, 1.9∼3.8% of hip for fat body type, were suggested for the appropriate reduction ratio for stretch skirt. 4. The result from this study for stretch skirt was as follows. For fat body type, W+2cm, W+0cm for waist and H+2cm, H+0cm for hip were appropriate for stretch skirt pattern. Therefore, different ease has to be applied to stretch skirt pattern according to the body parts, to make the skirt looks good, is appropriate for fat body type, and is satisfied with appearance and wearing satisfaction test.

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Comparison of Hydrodynamic Coefficients obtained through Implementation of Diverse Methods in Square Tank

  • Kang, Seunghyun;Yoon, Hyeon Kyu
    • 한국항해항만학회지
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    • 제38권1호
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    • pp.11-18
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    • 2014
  • To confirm whether the square tank at Changwon National University (CWNU) can be used for estimation of maneuverability, planar motion mechanism (PMM) test and circular motion (CM) test were performed for various conditions. PMM test can be implemented using an XY carriage and a yaw table in the square tank. However, sometimes test section is insufficient for PMM test owing to low length-breadth ratio of the tank. In addition, the speed of a towing carriage is also quite limited. Therefore, it would be useful if PMM test could be effectively performed diagonally, by establishing coupled control logic to drive three servomotors. In addition, Froude number dependency on the estimated hydrodynamic coefficients was checked. Furthermore, CM tests, which cannot be completed in a conventional linear towing tank, were performed, and its results were compared with the results of PMM test. The results of the PMM tests in the diagonal direction were consistent with the results of the test performed in the direction parallel to the sidewall. However, the results of the CM test were greater than those of the PMM test. This tendency was also observed in the results published at Ulsan University.

장정에 시행한 몇가지 평가기능 검사성적에 대한 고찰 (The Results of Various Vestibular Function Tests in Young Male Adult)

  • 박찬일;추광철;노관택
    • 대한기관식도과학회:학술대회논문집
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    • 대한기관식도과학회 1972년도 춘계종합 학술대회 초록집
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    • pp.2.3-2
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    • 1972
  • 평형기능검사는 평형장애의 객관적인 소견을 찾으려는 것이며 평형장해의 양상을 분석하고 장해부위를 추정하여 장해의 원인을 구명하는데 그 목적을 두고 있다. 이중 전정척수반사는 미로로부터의 자극이 전신횡문근군 근긴장에 영향을 주어 안정시 또는 운동시의 체위변화에 관여하고 있는 데에 그 임상적 의의가 있다. 이 반사는 안진과 같은 전정안반사를 일으킬 수 없는 미로에 대한 미약한 자극에 의하여도 야기될 수 있으므로 평형기능의 기본검사로 시행되어야 한다. 저자들은 100명의 건장한 청년 남자에서 단각직위검사, 보행검사, 족답검사 및 차안서자법을 시행하여 다음과 같은 성적을 얻었다. 1. 단각직위검사 30초간의 접상회수는 우각거상는 5회 이내이었으며 평균 0.68회로 나타났다. 2. 보행검사 전달시의 편기는 100cm 이내에 분포되어 있었으며 평균편기치는 우측으로 22.5cm, 죄측으로는 26.1cm이었다. 후진시의 편기는 140cm 이내에 분포되어 있었으며 평균편기치는 좌측으로 35.4cm, 좌측으로는 330cm이었다. 3. 족답검사 정상두위에서는 전방이행이 93%, 후방이행이 5%이었으며 이행각의 방향은 우측 36%, 좌측 50%, 회전각의 방향은 우측 53%, 좌측 36%로 나타났다. 후경두위에서는 전방이행이 94%, 후방이행이 3%이었으며 이행각의 방향은 우측 34%, 좌측 55%, 회전각의 방향은 좌측 50%, 좌측 42%로 나타났다. 평균편기치는 정상두위에서는 이행각 22.05도, 이행거이 48.95cm, 회전각 24.40도, 후경두위에서는 이행각 29.22도, 이행거이 44.17cm, 회전각 39.58도로 나타났다. 4. 차안서자법 편서방향은 정두위, 후경두위, 우경두위, 좌경두위 등에 따라 약간의 차이가 있으나 좌측편서가 54~69%로 우측편서 24.40%보다 많으며 나머지에서는 3~7% 편서를 보이지 않았다. 편서각도는 좌우 각각 두위변화에 따라 0~16도 사이에 분포되어 있으며 정두위에서는 0~12도, 평균편서각도는 4.15~5.76도 사이에 분포를 보이었다.

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