• Title/Summary/Keyword: Supports

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Analysis of Design Wind Load Level for System Supports Considering Local Basic Wind Velocity and Construction Period (지역별 기본풍속과 공사기간을 반영한 시스템 동바리 설계 풍하중 분석)

  • Lee, Sun-Woo;Won, Jeong-Hun;Mha, Ho-Seong
    • Journal of the Korean Society of Safety
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    • v.29 no.2
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    • pp.53-61
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    • 2014
  • This study evaluated wind loads considering a local basic wind velocity and construction periods to define the level of applied wind loads for system supports. Structural responses of system supports were examined and compared to those of system supports with the level of wind loads following various standards and specifications for permanent and temporary structures. And, the maximum combined stress ratios were estimated to evaluate the structural safety of a considered system support. From results, it was found that the wind load level should be applied in accordance with construction periods when estimating the safety of system supports. Looking into the response by change of the basic wind velocity according to local regions, it is no need to consider wind loads in regions with the basic wind velocity of 30 m/s. However, it was analyzed that wind loads should be considered in the regions with the basic wind velocity of 40 m/s or above. In addition, wind loads should be considered in designing system supports located at the region with the basic wind velocity of 35 m/s starting from construction period of 1.5 years. The standard specification for temporary work was analyzed as an incorrect standard in evaluating wind loads, since it underestimated the response of system supports in accordance with the local basic wind velocity and construction periods.

Introduction of Various Amine Groups onto Poly(glycidyl methacrylate)-g-MWNTs and their Application as Biosensor Supports (폴리(글리시딜 메타크릴레이트)가 그래프트된 다중벽 탄소나노튜브에 다양한 아민 그룹의 도입과 바이오센서 지지체로서의 응용)

  • Chung, Da-Jung;Kim, Ki-Chul;Choi, Seong-Ho
    • Polymer(Korea)
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    • v.36 no.4
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    • pp.470-477
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    • 2012
  • A tyrosinase-immobilized biosensor was developed based on various amine-modified multi-walled carbon nanotube (MWNT) supports for the detection of phenolic compounds. MWNTs with various amine groups were prepared by radiation-induced graft polymerization of glycidyl methacrylate (GMA) onto MWNT supports and the subsequent amination of poly(GMA) graft chains. The physical and chemical properties of the poly(GMA)-grafted MWNT supports and the aminated MWNT supports were investigated by SEM, XPS, and TGA. Furthermore, the electrochemical properties of the prepared tyrosinase-modified biosensor based on MWNT supports with amine groups were also investigated. The response of the enzymatic biosensor was in the range of 0.1-0.9 mM for the concentration of phenol in a phosphate buffer solution. Various parameters influencing biosensor performance have been optimized: binder effects, pH, temperature, and the response to various phenolic compounds. The biosensor was tested on phenolic compounds contained in two different commercial red wines.

Effects from Social Supports and Global Self-Worth on Children's Stresses (친구, 가족, 교사의 사회적 지지 및 자아가치감에 따른 아동의 스트레스)

  • Han, Jong-Hye;Park, Sung-Ok;Lee, Young-Whan
    • Korean Journal of Human Ecology
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    • v.6 no.1
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    • pp.15-27
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    • 1997
  • The purpose of this study was to examine the effects from social supports and global self-worth on stresses for the children. The subjects were 438 children of the 5th grade in Elementary School and the first grade in Junior High School in Taejeon. The instruments used for this study were Children's Social Support, Global Self-Worth and Stress Scale. The data were analyzed using t-test, Pearson's correlation, multiple regression and path analysis. The main results of the study were as follows; 1. The stresses were different depending on age. When the family and the teacher give higher social supports, the 5th graders have higher global self-worth. When the family gives higher social supports, the stresses were decreased for the 5th graders. When the children have higher global self-worth, the stresses were decreased. 2. When the first graders in Junior High School experienced higher global self-worth and social supports from their friends, family, teacher, the stresses were decreased. 3. The first graders in Junior High School experienced more stresses than the 5th graders in Elementary School in parent-related and academic-related domains. But the first graders in Junior High School experienced less stresses than the 5th graders in Elementary School in friend-related domains. 4. The path analysis showed that social supports from friends and family explained 15% of the stresses for the 5th graders in elementary school. Social support from friends, family, and teacher explained 28% of the stresses for the first graders in Junior High School. 5. For the 5th graders in Elementary School, social supports from friends and family had direct influences on the global self-worth. And the global self-worth had direct influence on children's stresses. But for the first graders in Junior High School, social supports from friends, family, and teacher had direct influences on the global self-worth. And the social supports from friends had direct and indirect effects on children's stresses. 6. For predicting the stresses, the most significant variable was the global self-worth for the 5th graders in Elementary School and the first graders in Junior High School.

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An Empirical Study on the Burnout of Nurses Based on the Job Demand-Control Model (직무요구-통제 모형에 의한 간호사의 소진(Burnout)에 관한 연구)

  • Park, Sang-Eon;Han, Su-Jung
    • Korea Journal of Hospital Management
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    • v.11 no.2
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    • pp.32-60
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    • 2006
  • Based on the Job Demand-Control model which was proposed by R. A. Karasek, this study was designed to investigate the relationships among job demand, job control, and job burnout of nurses. In addition, the other aim of the present study was to test the moderating or buffering role of social supports in the relationship between the job demand and job burnout. The analysis based on data collected from 239 nurses who are working in two general hospitals has produced the following results. We found that job demand was primarily related to the exhaustion component of burnout, whereas (lack of) job control was related to the disengagement dimension of burnout. And social supports from the supervisor attenuated the disengagement, whereas social supports from the colleague diminished the exhaustion. But, we found no interaction effects that were expected in the hypotheses. Specifically, social supports didn't buffer the negative effects of job demand on burnout, while job control had the moderating effect which was in opposite direction. The implications of these analyses and limitations of the study were then discussed.

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Effects from the Interaction of Ego-Resilience, Social Supports in the School Adjustment of Elementary School Children (초등학생의 학교적응에 대한 자아탄력성과 사회적 지지의 상호작용효과)

  • Song, Young-Kyoung;Kim, Yeong-Hee;Hwang, Seong-Sil
    • Korean Journal of Human Ecology
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    • v.20 no.1
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    • pp.1-19
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    • 2011
  • The purpose of this study was to investigate the interactions of ego-resilience and social supports in the school adjustment in children. The subjects of this study were 479 children drawn from the fourth and sixth grades of three elementary schools in Cheongju city. The pilot study was done to examine the applicability of survey instruments. Data was analyzed by frequency, percentage, Cronbach's t-test, ANOVA with Tukey post-hoc test, correlation, and hierarchial analysis using the SPSSWIN program. The results of this research were as follows: First, the results showed that the effects of the interaction of ego-resilience and social supports on school adjustment were different according to the children's gender and age. Second, teacher supports had influence on school life satisfaction, interest in the subject, attitude in class, and observance of school rules according to the children's gender and age. Finally, overall, the influence of school life satisfaction, interest in subjects, attitude in class, and observance of school rules was greater for girls than boys.

Effect of Horizontal Connection and Slope on Buckling Characteristics of Single Pipe (단관 파이프의 좌굴특성에 대한 수평연결재 및 기울기의 영향)

  • Lee, Jin Seop;Lee, Yeon Su;Oh, Tae Keun
    • Journal of the Korean Society of Safety
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    • v.30 no.2
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    • pp.48-55
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    • 2015
  • The number of collapse accidents relevant to form support since 2003 is 30 on the basis of statistical data from Ministry of Employment and Labor,. Total number of casualty was 138 (47 for deaths and 91 for injuries). The accident severity rate was high because the 4.6 casualties per one accident were occurred averagely although the incident rate was relatively low. Especially, one of form support members, the pipe supports have not been equipped adequately so that the accidents could have happened. In this regard, this study performed buckling test related to the effect of horizontal connection and slope in the single pipe which is one of typical pipe supports. The buckling load, which was estimated from the single pipe with the horizontal connectors theoretically and experimentally, was increased as more than 2 times compared to the buckling load obtained from the pipe supports without the connector. The buckling load was reduced as more than 26%, 34% slope of the single pipe comparing with 5% and 10% slope, respectively. Thus, the purpose of this study is to provide the guideline for installation and the maintenance of the pipe supports legally and institutionally to prevent the collapse accidents of the pipe supports.

Effect of Chemical Treatment on Performance Behaviors of PtRu/GNFs Catalysts for DMFCs (직접 메탄올 연료전지용 PtRu/GNF 성능에 대한 화학적 처리의 영향)

  • Park, Soo-Jin;Park, Jeong-Min
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.369-372
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    • 2009
  • In the present study, the effect of chemical treatment on graphite nanofibers (GNFs) supports with various concentrated nitric acids was investigated for methanol oxidation. To optimize the electrocatalytic activity, PtRu catalysts were deposited on GNF supports by impregnation method. The surface and structural properties of the GNF supports were characterized by X-ray photoelectron spectroscopy (XPS), element analyzer (EA), and X-ray diffraction (XRD). The morphology of the catalysts was observed by means of transmission electron microscopy (TEM). The electrocatalytic activity of PtRu/GNF catalysts was investigated by cyclic voltammetry measurement. As a result, the oxygen functional groups were introduced on the GNF supports and were gradually increased with increasing of concentrated nitric acid, causing the smaller particle size and higher loading level. And the electrocatalytic activity of the catalysts for methanol oxidation was gradually improved. Consequently, it was found that chemical treatments could influence on surface properties of the carbon supports, resulting in enhancing the electrocatalytic activity of the catalysts for DMFCs.

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Vibration Analysis of Partially Fluid-filled Continuous Cylindrical Shells with Intermediate Supports (유체가 부분적으로 채워진 내부지지 연속 원통셸의 진동해석)

  • 김영완
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.3
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    • pp.244-252
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    • 2004
  • The theoretical method is developed to investigate the vibration characteristics for the partially fluid-filled continuous cylindrical shells with the intermediate supports. The intermediate supports are simulated by two types of artificial springs : the translational spring for the translation for each direction and the rotational spring for a rotation. The springs are continuously distributed along the circumferential direction. By allowing the spring stiffness to become very high compared to the stiffness of the structure, the rigid intermediate supports are approximated. In the theoretical procedure, the Love's thin shell theory is adopted to formulate the theoretical model. The frequency equation of the continuous cylindrical shell is derived by the Rayleigh-Ritz approach based on the energy method. Comparison and convergence studies are carried out to verify and establish the appropriate number of series term and the artificial spring stiffness to produce results with an acceptable order of accuracy. The effect of intermediate supports, their positions and fluid level on the natural frequencies and mode shapes are studied.

Case Study and Needs Analysis on Convergence Education in Engineering Colleges (공과대학 융합교육에 대한 사례조사 및 요구분석)

  • Jin, Sung-Hee;Shin, Soobong
    • Journal of Engineering Education Research
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    • v.16 no.6
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    • pp.29-37
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    • 2013
  • The necessity of convergence education is more emphasized based on the education policy for fostering creative men of talent. Inside universities, however, programs for training talented individuals are still at primary stage. Universities understanding the importance of convergence education and thus founding some major fields of convergence studies have experienced hosts of troubles. The paper discusses the necessary plans of supports from the government and the university to activate the convergence education in accord with the social demands. Twenty-eight professors in engineering colleges participated in the survey for reviewing the required factors for the convergence education. In addition, structured interviews were carried out with three specialists working in industry and academic area of convergence technology. The study could suggest the following activation plans based on the government supports: (1) establishing a support center of convergence education, (2) founding a major field of convergence, (3) developing curriculums and curriculum subjects, and (4) hosting related conferences and forums. Also, the study could suggest the following activation plans based on the university supports: (1) developing special programs on convergence education in accord with the industrial demands, (2) revising regulations and administrative systems more flexible for the convergence education, and (3) providing incentives to the participants in the convergence education.

Effect of Strontium Carbonate Content on Flexural Strength of Clay-Based Membrane Supports

  • Eom, Jung-Hye;Kim, Young-Wook;Song, In-Hyuck
    • Journal of the Korean Ceramic Society
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    • v.52 no.6
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    • pp.467-472
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    • 2015
  • The effect of $SrCO_3$ content on the microstructure, porosity, flexural strength, and pore size distribution of clay-based membrane supports was investigated. Green compacts prepared from low cost materials such as kaolin, bentonite, talc, sodium borate, and strontium carbonate were sintered at $1000^{\circ}C$ for 8 h in air. It was possible to control the porosity of the clay-based membrane supports within the range of 33% to 37% by adjusting the $SrCO_3$ content. The flexural strength of the clay-based membrane supports was found to strongly depend on their porosity. In turn, the porosity was affected by the $SrCO_3$ content. The average pore size and flexural strength of the clay-based membrane supports containing 4 wt% $SrCO_3$ were $0.62{\mu}m$ and 33 MPa at 34% porosity.