• 제목/요약/키워드: cohesion test

검색결과 303건 처리시간 0.025초

개인과 집단의 특성이 지식창출에 미치는 영향 (The Effect of Individual and Team Characteristics on Knowledge Creation : An Analysis by Hierarchical Linear Model (HLM))

  • 강소라;김민선
    • Journal of Information Technology Applications and Management
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    • 제17권4호
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    • pp.19-38
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    • 2010
  • This paper investigates the effect of stress on knowledge creation. The goal stress of resource inadequacy and job stress had negative influences on knowledge creation. However, the cohesion and mastery climate of team had positive influence on knowledge creation. Therefore this paper verifies the moderate role of the cohesion and mastery climate of team on the relationship between stress and knowledge creation. The model developed was tested using data collected from knowledge based industry with 375 members in 69 teams in 12 different firms. A Hierarchical Linear Model (HLM) was used to test the hypotheses generated from the model. Results show that job stress had a negative influence on knowledge creation as we expected but the goal stress didn't. The mastery climate of team affected knowledge creation positively and moderated the relationship between the goal stress and knowledge creation. Furthermore, the team cohesion had a positive influence on knowledge creation. The study provided some implications that practitioners should consider the stress when they design jobs for team members and suggest them the way to manage their job stress when they work.

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The Changes in the Physical Properties of Soil with Tillage Methods (I)

  • Park, Jun-Gul;Lee, Gu-Seung;Cho, Sung-Chan;Chang, Young-Chang;Noh, Kwang-Mo;Chung, Sun-Ok
    • Agricultural and Biosystems Engineering
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    • 제6권2호
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    • pp.59-64
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    • 2005
  • In the study, the cone index, the cohesion and the internal resistant angle of soil were measured before and after tillage in order to suggest relative improvement in soil properties. The tillage methods tested in the study were five combinations of plow and rotary tillage operation and the experiments were performed on five selected test fields. The maximum tillage depth was 20 cm under the ground. The CIs for all the tillage operations were improved in comparison with those before tillage. The best combination of tillage operations for improving the CIs of soil was one plow operation followed by one rotary. After applying the tillage operations, the internal resistance angle reduced by 7-8 degree and the cohesion decreased up to about $1N/cm^2$ in comparison with those before tillage. We concluded that the cone index, the cohesion and the internal resistant angle of soil could be used as measures for representing the relative degree of tillage for a specific tillage operation. In addition, the study was useful as a basic research tool for developing an decision making system that determines an optimal tillage method with soil properties.

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일차파괴된 암반사면의 전단강도 및 보강설계법 고찰 (A study on the determination of shear strength and the support design of pre-failed rock slope)

  • 조태진;김영호
    • 터널과지하공간
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    • 제5권2호
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    • pp.104-113
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    • 1995
  • Shear strength of the discontinuity on which the pre-failure of rock slope was occurred during surface excavation was measured through the direct shear test using core samples obtained in-situ. Internal friction angle was increased as the roughness of discontinuity surface(JRC) was increased. Results of the tilt test using core samples of higher JRC also showed very similar trend as those of the direct shear test. When the samples replicated from natural cores were used int he tilt test, results of friction angles showed almost perfect continuation of the residual friction angles from the direct shear test. However, when the gouge material existed in the discontinuity the internal friction angle strongly depended upon the rate of filling thickness to the height of asperity irrespective of the JRC. Based on the results of both direct shear test and tilt test internal friction angle and cohesion of discontinuity, which reflect the in-situ conditions fo pre-sliding failure and also can be used for the optimum design of support system, were assessed. Two kinds of support measures which were expected to increase the stability of rock slope were considered; lowering of slope face angle and installation of rock cable. But, it was found that the first method might lead to more unstable conditions of rock slope when the cohesion of discontinuity plane was negligibly low and in that case the support systems of any kind which could exert actual resisting force were needed to ensure the permanent stability of rock slope.

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An experimental study on shear mechanical properties of clay-concrete interface with different roughness of contact surface

  • Yang, Wendong;Wang, Ling;Guo, Jingjing;Chen, Xuguang
    • Geomechanics and Engineering
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    • 제23권1호
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    • pp.39-50
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    • 2020
  • In order to understand the shear mechanical properties of the interface between clay and structure and better serve the practical engineering projects, it is critical to conduct shear tests on the clay-structure interface. In this work, the direct shear test of clay-concrete slab with different joint roughness coefficient (JRC) of the interface and different normal stress is performed in the laboratory. Our experimental results show that (1) shear strength of the interface between clay and structure is greatly affected by the change of normal stress under the same condition of JRC and shear stress of the interface gradually increases with increasing normal stress; (2) there is a critical value JRCcr in the roughness coefficient of the interface; (3) the relationship between shear strength and normal stress can be described by the Mohr Coulomb failure criterion, and the cohesion and friction angle of the interface under different roughness conditions can be calculated accordingly. We find that there also exists a critical value JRCcr for cohesion and the cohesion of the interface increases first and then decreases as JRC increases. Moreover, the friction angle of the interface fluctuates with the change of JRC and it is always smaller than the internal friction angle of clay used in this experiment; (4) the failure type of the interface of the clay-concrete slab is type I sliding failure and does not change with varying JRC when the normal stress is small enough. When the normal stress increases to a certain extent, the failure type of the interface will gradually change from shear failure to type II sliding failure with the increment of JRC.

토목섬유 접촉면의 역학적 특성 개선에 관한 연구 (A Study on the Improvement Mechanical Properties of Geosynthetic Interface)

  • 남용;김광호;권정근;임종철;서재찬
    • 한국지반환경공학회 논문집
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    • 제11권3호
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    • pp.23-32
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    • 2010
  • 흙채움 마대는 현장의 재료를 사용하여 간편하게 사면 및 제방의 복구나 보강에 사용되고 있다. 이런 흙채움 마대의 전단저항력을 증가시키기 위해 흙채움 마대 상 하면에 벨크로(Velcro)를 부착한 흙채움 마대가 개발되었으며, 벨크로를 부착한 흙채움 마대의 역학적 특성을 분석하기 위해 대형직접전단실험과 원호파괴를 가정한 실내모형실험이 수행되었다. 실제 벨크로가 부착된 마대를 이용해 사면을 설계하기 위해 흙-토목섬유 요소실험을 실시하여 강도정수를 파악하였다. 그리고 사면형성 시 벨크로와 흙채움 마대가 혼재하고 있기 때문에 정확한 파괴면을 알 수 없다. 따라서 실내모형실험을 통해 내적파괴에 대한 거동을 분석하고, 역해석을 통해 설계강도정수를 제안하였다. 흙-토목섬유의 요소실험결과, 벨크로의 부착으로 인해 흙채움 마대 상호간의 전단저항 정수인 내부마찰각과 점착력의 증가가 나타났으며, 특히 내부마찰각보다는 점착력의 뚜렷한 증가가 나타난 것으로 분석되었다. 또한, 실내모형실험 결과, 지지력이 20%이상 증가해 대형장비의 주행성 증가와 시공속도의 증대를 가져올 것으로 판단된다.

경운작업에 의한 토양 역학적 특성의 변이 특성 (Analysis of Variations in Mechanical Properties of Soil by Tillage Operations)

  • 박준걸;이규승;조성찬;노광모;정선옥;장영창
    • Journal of Biosystems Engineering
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    • 제32권4호
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    • pp.215-222
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    • 2007
  • In the study, the cone index, the cohesion and the internal friction angle of soil were measured before and after tillage in order to suggest relative improvement in soil properties by comparing the two measured values before and after tillage. The tillage methods tested in the study were five combinations of plowing and rotovating; one plow tillage operation, one plow followed by one rotary, one plow followed by two rotary, one rotary without plow and two rotary without plow. The experiments were performed in a soil bin in Sunggyunkwan Univ. and in four selected test fields in Yeoju, Seodun-Dong, Suwon (especially, two different fields) and Chungju. In general, the internal friction angle and cohesion of soil increased with the increase of soil compaction. After applying the tillage operations, the internal friction angle reduced by 14 degree and the cohesion decreased up to about $2.2N/cm^2$ on the soil bin in comparison with those before tillage. The two values, however, reduced by 9 degree and up to about $1.0N/cm^2$ on the tested fields. The CIs for all the tillage operations on the soil bin and on 4 different test fields were decreased by 800 kPa in comparison with those before tillage. The best combination of tillage operations for decreasing the CIs of soil was one plow operation followed by one rotary. The CIs for one plow operation followed by two rotary were slightly higher than that for one plow operation followed by one rotary because one plow operation followed by two rotary crushed down the soil excessively, so that the porosity of soil decreased.

암 환아 어머니의 희망, 부담감과 가족기능 (The Hope, Burden, and Family Function in Mothers of Children with Cancer)

  • 박호란;박선남;정경희;김혜자
    • Child Health Nursing Research
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    • 제7권1호
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    • pp.51-61
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    • 2001
  • The purpose of the descriptive correlation study was to examine relations among the hope, the burden and the family function in mothers caring for children with cancer. 145 mothers completed the three questionaires of the study divided into tree sections: a) The Hope Scale, b) The Burden Scale, c) FACES-Ⅲ. The collected data was analysed with t-test, ANOVA, Scheffe test and Pearson correlation coefficients. The results were as follows: 1) The average age of mothers of children with cancer was 35.6 years old and the ages between 30 to 39 were the most abundant. 57.3% of the mothers had an education level of below high school education and 66.0% had religion. The average age of the children was 8.6 years old. Ages between 1 to 7 were the most and 60.8% were diagnosed as leukemia. 2) Regarding the section of degree of burden, mothers of children with cancer marked 2.6 out of 5, and the degree of hope 3.2 out of 4. The result for family function came out to be 3.5 out of 5, an average of family cohesion of 3.9 and family adaptation of 3.1. 3) There were significantly less burden to the mothers who were living together with a spouse compared to the mothers who were not. Also mothers who replied that they preserved good health came out to be exposed to less burden compared to the mothers who did not. In analysing hope according to the general characteristics of mothers of children with cancer, mothers who were employed marked high in the degree of hope compared to unemployed mothers. Furthermore, the degree of family cohesion marked higher with mothers who had higher education of college graduate, mothers with religion and mothers with a monthly family income of over ₩3,000,000, compared to the group of mothers with lower education of high school graduate, non-religious or with a monthly family income of less than ₩1,000,000. 4) Excluding the fact that the group sorted with children diagnosed as leukemia marked a perceivably high score regarding family cohesion, compared to groups with other cancers, the degree of burden, hope and family cohesion did not show any noticeable difference according to characteristics of children with different cancers. 5) In the correlation of the hope, the burden and the family function regarding the mothers of children with cancer, the burden did not have any manifest relationship with hope or family function. However, the degree of hope and family function cohesion had a direct proportional relationship, as family cohesion marked higher when the degree of hope were high.

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중환자가 지각한 가족지지와 절망감과의 관계연구 (Family Support and Hopelessness in Patients Admitted to Neuro-Surgical Intensive Care Unit)

  • 김현실;조미영
    • 대한간호학회지
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    • 제22권4호
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    • pp.620-635
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    • 1992
  • This study identified correlations between perceived family support and hopelessness in patients admitted to Neuro - surgical Intensive Care Units. The purpose was to enhance theoretical understanding of the relationships of these two variables. The subjects of this study were 51 patients admitted to N-lCU, at three general hospitals in Seoul. Data were collected by researcher in structured interviews from Aug. 12 to Oct. 13, 1992. The research tools were parts of the Moos Family Environment Scale and the Beck Hopelessness Scale. The general characteristic data were analyzed for frequency and percentage ; the hypothesis was tested by the pearson product Moment Correlation Coefficient. After normality tests by using Kolmogorov - Sminorvtest, and T- test, ANOVA and Mann-Whitney U test, Kruskal -Wallis test were used on the Family Support and the Hopelessness about general charcteristics. The results of the above analysis were as follows 1) The average family support score for the group was 63.61 (tool average 51) and item average was 3.74 (tool item average 3) : the family support score of this sample was higher than average. The average family cohesion score of family support was 35.25 (tool average 27) and item average was 3.91 (tool item average 3). The average family expression score of family support was 28.35 (tool average 24) and item average was 3.57 (tool average 3). In this sample, perceived family expression was lower than family cohesion. 2) The average hopelessness score was 45.88 (tool average 60) and item average was 2.29 (tool item average 3) : the hopelessness score of this sample was low in comparison to the average. 3) The hypothesis in this study was supported. The main hypothesis that the higher the perceived family support level, the lower the level Of the hopelessness, was Supported (r=-.3869 p=.003). The sub-hypothesis that the higher the perceived family cohesion level, the lower the level of hopelessness, was supported(r=-.3688 p=.004). The sub-hypothesis that the higher the perceived family expression level, the lower the level of hopelessness, was supported (r=-.3068 p=.014). 4) General characteristics of the objects related to family support were ‘economic status’(p=.025) and ‘helping person’(P=.044) : the higher the economic status, the greater the family support. When the patient identified the helping person as a spouse, family support was rated more highly. The only general characteristic related to family cohesion was ‘helping person’(p=.041). No general characteristics were related to family expression. 5) The one general characteristic related to hopelessness was ‘education’(p=.002) : the higher their education, the lower their hopelessness. For these ICU patients, were related perceived family support and hopelessness, and family expression level was low in comparison to family cohesion level. The perceived family support of these seriously ill patients in situational crisis may have influenced the patient's emotional reaction of hopelessness. This study concluded that nurses in the ICU confirm the family support of the patient, and involve the family as the most intimate support systems in the care of the patient to help reduce the patient's hopelessness.

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시멘트계 주입재료의 암반그라우팅 효과 (Grouting Effects of Microfine Cement in the Rock-based Sites)

  • 공진영;김찬기;박진환;천병식
    • 한국지반환경공학회 논문집
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    • 제11권12호
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    • pp.37-45
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    • 2010
  • 초미립자시멘트는 입자 크기가 마이크로화되어 실트성 지반까지 주입가능하지만 점성이 높아 침투성이 저하되는 단점이 있다. 본 연구에서는 유동화제를 사용하여 점성을 낮춘 초미립자주입재의 그라우팅 효과를 평가하고자 암반에서 초미립자주입재와 보통시멘트주입재의 주입효과를 비교하였다. 시추조사, 현장수압시험, 공내재하시험, 공내전단시험, 단위주입량분석, p~q~t chart 유형 분석을 실시하였다. 시험 결과 초미립자주입재를 사용하는 경우가 보통시멘트 주입재를 사용하는 경우보다 투수성, 탄성계수 및 변형계수, 단위주입량 및 주입재 회수율 등 측면에서는 유리하지만 전단응력 측면에서는 차이가 거의 없는 것으로 나타났다.

수학능력시험 영어 읽기 지문의 응집성과 문항 난이도 간의 상관관계 분석 (Analysis of Correlation Between Cohesion and Item Difficulty in English Reading Section of CSAT)

  • 황이수;이제영
    • 한국콘텐츠학회논문지
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    • 제20권5호
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    • pp.344-350
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    • 2020
  • 본 연구의 목적은 수학능력시험 영어 영역 문항의 정답률에 영향을 미치는 응집성 관련 텍스트 요인을 찾기 위함이다. 이를 위해, 2014~2018학년도 수능 및 수능 모의고사의 읽기 지문 299개를 수집하여 응집성 관련 지표를 코메트릭스를 통해 분석하고 이를 실제 문항 정답률과 상관분석하였다. 이를 통해 얻어진 결론은 다음과 같다. 첫째, 문장 사이의 특정 논항이 반복되어 응집성이 강해지면 학습자의 언어적 부담이 줄어들면서 문항 정답률이 상승하는 경향이 있었다. 둘째, 잠재 의미 분석의 8개 하위 영역과 문항 정답률 사이에는 통계적으로 유의한 상관관계가 발견되지 않았다. 마지막으로 본 연구의 교육적 함의와 후속연구를 위한 제언을 논의하였다.