• Title/Summary/Keyword: reinforcing effect

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Nonlinear Analysis of Nuclear Reinforced Concrete Containment Structures under Accidental Thermal Load and Pressure (온도 및 내압을 받는 원자로 철근콘크리트 격납구조물의 비선형해석)

  • Oh, Byung Hwan;Lee, Myung Gue
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.3
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    • pp.403-414
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    • 1994
  • Nonlinear analysis of RC containment structure under thermal load and pressure is presented to trace the behaviour after an assumed LOCA. The temperature distribution varying with time through the wall thickness is determined by transient finite element analysis with the two time level scheme in time domain. The layered shell finite elements are used to represent the containment structures in nuclear power plants. Both geometric and material nonlinearities are taken into account in the finite element formulation. The constitutive relation of concrete is modeled according to Drucker-Prager yield criteria in compression. Tension stiffening model is used to represent the tensile behaviour of concrete including bond effect. The reinforcing bars are modeled by smeared layer at the location of reinforcements accounting elasto-plastic axial behaviors. The steel liner model under Von Mises yield criteria is adopted to represent elastic-perfect plastic behaviour. Geometric nonlinearity is formulated to consider the large displacement effect. Thermal stress components are determined by the initial strain concept during each time step. The temperature differential between any two consecutive time steps is considered as a load incremental. The numerical results from this study reveal that nonlinear temperature gradient based on transient thermal analysis will produces excessive large displacement. Nonlinear behavior of containment structures up to ultimate stage can be traced reallistically. The present study allows more realistic analysis of concrete containment structures in nuclear power plants.

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A Study on the Security Problems of Smart TV and Consumer's Purchase Intention (스마트TV의 보안 문제와 소비자의 구매의도에 관한 연구)

  • Cho, Sung-Phil;Lee, Gi-Hyouk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.7
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    • pp.382-393
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    • 2017
  • Smart TV sareequipped with an operating system and combined with internet functionality. They can use various apps and contents, and provide personalized and interactive services. However, the Internet connectivity of smart TVs has several security vulnerabilities that can cause significant personal and social harm. Therefore, it is necessary to develop a smart TV with a higher level of security than is currently available. In this study, we analyze consumers' purchase intention for smart TVs with security reinforcement by applying the UTAUT2 model. The results are as follows. Firstly, it was found that performance expectancy, social influence, facilitating conditions and price value, as important variables under the existing UTAUT2 model, have significant effects on purchase intention. Secondly, effort expectancy did not have a positive impact on purchase intention. Thirdly, there was a moderating effect of gender on social influence. According to the results of this study, social influence has the most powerful effect on the purchase intention of smart TVs with security reinforcement. Therefore, in order to improve the purchase intention of smart TVs, it is necessary to expand the publicity activities designed to promote the necessity and importance of reinforcing the security of smart TVs and make them easier to use.

An Outlook of the Oriental and Western Medical Diagnosis and Treatment on Large Bowel Cancer (대장암(大腸癌)의 동서의(東西醫) 결합(結合) 진치근황(診治近況))

  • Kim, Byeong-Ju;Moon, Goo
    • THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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    • v.5 no.1
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    • pp.1-17
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    • 1999
  • Large bowel cancer shows the 4-5th frequency in cancers that occurs in Korea. The western medicine cures the Large bowel cancer by radiation, surgery and chemotherapy. While, Oriental medicine cures the Large bowel cancer by Herb-drugs, acupuncture, moxa and et al. With just one way of treating Large bowel cancer can't be effective remedy. Because each medicine has a strength and weakness, it is effective treatment when two medicine combines and supplement each other. We got the following result about a trend of oriental and western combination treatment for Large bowel cancer through studding records. 1. In Large bowel cancer, colon cancer is referred hematochezia(腸風下血), rectal cancer is refereed enterotoxin(腸毒), and anal cancer is accumulation of pathogens in yin(結陰). 2. The western medicine treats Large bowel cancer patient with surgery first. They need on assembly treatment such as chemical, radiation and immune treatment. In oriental medicine, they treats Large bowel cancer patients with differentiation of symptom and signs and treatment(辨證施治) for example, insufficiency of spleen and stomach(脾胃虛弱), collapse of the spleen-ql(脾氣下陷), stagnation of blood stasis and toxic agent(瘀毒內結), reinforcing both qi and blood(脾血下陷), stagnation of damp-phlegm(痰濕凝結) and cure for them by acupuncture and moxa too. 3. In combination with oriental and western medical treatment princple of Large bowel cancer by each stage is as follows. First stage is cured with radical surgery and herb-drugs without chemotherapy. The intermediate and terminal stage patients is used radiation before surgery, or after palliative surgery cour with chemotherapy, radiation and Herb-drugs. In terminal stage patients, unable for surgery, is used combination between chemotherapy, palliative radiation and Herb-drugs. 4. After radiation surgery, the terminal stage patients who have extensively lymph node metastasis or local contraindication is able to undergo combination of Herb-durgs and chemotherapy. 5. The cure-effect with oriental and western medicine combination treatment was better than that just with oriental or western medical treatment. 6. The merits of oriental and western medicine combination treatment lengthen one's life and diminish the bad effect of chemotherapy and complete radiation treatment, prevent from relapsing, maintain the balance in their environment of body and improve immunity.

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The Effect of Job Competencies Education in First Job Satisfaction (대학생의 직무능력 향상 교육이 첫직장 만족에 미치는 영향)

  • Lee, Jeong-Sook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.12
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    • pp.542-550
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    • 2016
  • This study analyzed the direct and indirect effects of job competency education on job goal setting, job preparation behavior and first job satisfaction from the perspective that successful employment requires improving the job ability needed for college students. Data on 5,044 students were analyzed based on the 2013GOMS of Graduates Occupational Mobility Survey(GOMS). The study findings are summarized as follows. First, job competency education not only acted positively on job goal setting but also contributed to promoting job preparation behavior. Second, job preparation behavior contributed to improving satisfaction with the first job. Third, indirect effects of job competency education and job goal setting in first job satisfaction. In conclusion, job competencies enhances the possibility that college students may obtain their wanted job by setting a clear goal for their job and having a positive effect on the required behavior. Accordingly, college student should try to reinforce their special capability to accomplish the given job as career professionals in consideration of their aptitude rather than devoting themselves to reinforcing their basic capability such as linguistic ability. For this purpose, both universities and the government should develop educational programs for college students to grasp their aptitude and cultivate their special ability to become career professionals and provide a foundation for them to become talented professionals armed with special capability by proving support for job ability improvement.

Quantitative Damage Evaluation of Fiber-Reinforced Cement Composite Using Acoustic Emission Technique (음향방출 기법을 이용한 섬유보강 시멘트 복합체의 정량적 손상평가)

  • Lee, Young-Oh;Yun, Yeo-Jin;Yun, Hyun-Do
    • Journal of the Korea Concrete Institute
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    • v.21 no.4
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    • pp.457-464
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    • 2009
  • Fiber is an important ingredient in fiber-reinforced cement composite (FRCC) which can control fracture of cement composite by bridging action. In compliance with the action of the fiber and the aggregate size, it also showed a different failure mechanism. For practical application, it is needed to investigate the fracture behavior of the FRCC and to understand the micro-mechanism of cement matrix with reinforcing fiber. In order to evaluate a characteristics of fracture process in the FRCC, acoustic emission (AE) technique was used for the analysis and evaluation of FRCC damage by acoustic emission under flexural and cyclic compressive loadings. The AE signals were monitored by AMSY4 AE instrument during the entire loading period. The specimens are reinforced with 0, 1.0, 1.5 and 2.0% (by volume) Polyvinyl alcohol (PVA) fiber. The test results showed that the damage progress of the FRCC was characteristic for the fiber replacement ratio. As a result of analyzing the felicity ratio (FR) values, it is shown that this values can be used for evaluating the degree of FRCC damage. On the whole the felicity ratio values of FRCC are shown between 0.4 and 1.1. And, the AE kaiser effect was shown in the all FRCC specimen. In addition, the damage behavior and the microscopic fracture process of the FRCC are evaluated using the AE parameters, such as calm ratio, b-value and felicity ratio. The purpose of this reserch was to advance the state of knowledge regarding the applicability of acoustic emission as an evaluation method for FRCC.

A Case Study of Post-Grouted Drilled Shaft in Weathered Rock (풍화암소켓 대구경 현장타설말뚝의 선단보강그라우팅 사례)

  • Kwon, Oh-Sung;Jung, Sung-Min;Choi, Yong-Kyu
    • Journal of the Korean Geotechnical Society
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    • v.27 no.6
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    • pp.5-16
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    • 2011
  • Post-grouting for the drilled shaft is known to remarkably increase the end bearing capacity of pile by consolidating and reinforcing the disturbed ground containing slime around the pile tip. However, the general design guideline for post-grouting has not been established yet in Korea. Especially in the domestic application, the post-grouting is employed just for repairing the pile with unacceptable resistance rather than for increasing the design resistance of pile. Therefore, little is reported about the effect of post-grouting on the pile resistance itself. In this study, the effect of post-grouting on the resistance of drilled shafts installed in the weathered rock in Korea was estimated by performing the bi-directional load tests on the piles with and without the post-grouting. The test results presented that the initial slope of end bearing-base displacement curve in the pile with post-grouting was 4 times higher than that without post-grouting. At the acceptable settlement (1% of pile diameter), the end bearing capacities of piles with and without the post-grouting were estimated to be 12.0 MPa and 7.0 MPa, respectively, which indicate that the post-grouting could increase the end bearing resistance of pile in weathered rock more than 70%.

[ $SiO_2$ ] Effect on the Electrochemical Properties of Polymeric Gel Electrolytes Reinforced with Glass Fiber Cloth ($SiO_2$가 유리섬유로 보강된 고분자 겔 전해질의 전기 화학적 특성에 미치는 영향)

  • Park Ho Cheol;Kim Sang Heon;Chun Jong Han;Kim Dong Won;Ko Jang Myoun
    • Journal of the Korean Electrochemical Society
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    • v.4 no.1
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    • pp.6-9
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    • 2001
  • [ $SiO_2$ ] effect on the electrochemical properties of polymeric gel electrolytes(PGEs) reinforced with glass fiber cloth(GFC) was investigated . PGEs were composed of polyacrylronitrile(PAN), poly(vinylidenefluoride-co-hexafluoropropylene) (P(VdF-co-HFP)), $LiClO_4$ and three kind of plasticizer(ethylene carbonate, dietyl carbonate, propylene carbonate). $SiO_2$ was added to PGEs in the weight fraction of 10, 20, $30\%$ respectively. PGEs containing $SiO_2$ showed conductivity of over $10^{-3}S/cm\;at\;23^{\circ}C$ and electrochemical stability window to 4.8V. In the impedance spectra of the cells, which were constructed by lithium metals as electrodes, interfacial resistance increased due to growth of passivation layer during storage time and remarkable difference was not observed with content of $SiO_2$. In the impedance spectra of the lithium ion polymer batteries consisted of $LiClO_2$ and mesophase pitch-based carbon fiber(MCF), ohmic cell resistance of $SiO_2-free$ PGE was changed continuously with number of cycle, but those of $SiO_2-dispersed$ PGEs were not. Discharge capacity of the PGE containing $20wt\%\;SiO_2$ showed 132 mAh/g at 0.2C rate and $85\%$ of discharge capacity was retained at 2C rate.

A Study on the Effect of Motivation and Satisfaction on Experiential Entrepreneurship Education (참여동기와 창업멘토링이 창업교육만족도 및 창업의지에 미치는 영향: '학생 창업유망팀 300(U-300)' 사례를 중심으로)

  • Kim, Yong Tae
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.2
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    • pp.267-277
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    • 2020
  • In recent years, universities are actively developing and applying regular start-up curriculum, comparisons and activities in order to revitalize various forms of business-oriented academic programs. In addition, the government has established various experiential entrepreneurship education programs such as "Student Entrepreneurship Team 300 (U-300)" to support professional entrepreneurship education such as entrepreneurship mentoring for entrepreneurship clubs in universities nationwide. Therefore, this study empirically verified the influence of participation motivation,, mentoring function, and mentor competence on entrepreneurship education satisfaction and entrepreneurship will for participants of experiential entrepreneurship programs centered on entrepreneurship mentoring. The results of the study were as follows: First, the motivation to participate in entrepreneurship education and mentoring capacity had a significant positive effect on the satisfaction of entrepreneurship education. It became. The findings of this study suggest that in order to more effectively promote entrepreneurship education in the university, which is now quantitatively expanded, it is necessary to improve various ways of creating qualitative effects such as expansion of experiential teaching methods and entrepreneurship mentoring. We believe this could provide policy implications for reinforcing the expertise of entrepreneurs who conduct mentoring.

A Study on the Prediction of Elastoplastic Behavior of Carbon Nanotube/Polymer Composites (계면 결합력과 나노튜브의 응집에 따른 나노튜브/고분자 복합재의 탄소성 거동 예측에 대한 연구)

  • Yang, Seunghwa;Yu, Suyoung;Ryu, Junghyun;Cho, Maenghyo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.6
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    • pp.423-430
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    • 2013
  • In this research, a paramteric study to account for the effect of interfacial strength and nanotube agglomeration on the elastoplastic behavior of carbon nanotube reinforced polypropylene composites is performed. At first, the elastoplastic behavior of nanocomposites is predicted from molecular dynamics(MD) simulations. By combining the MD simulation results with the nonlinear micromechanics model based on the Mori-Tanaka model, a two-step domain decomposition method is applied to inversely identify the elastoplastic behavior of adsorption interphase zone inside nanocomposites. In nonlinear micromechanics model, the secant moduli method combined with field fluctuation method is used to predict the elastoplastic behavior of nanocomposites. To account for the imperfect material interface between nanotube and matrix polymer, displacement discontinuity condition is applied to the micromechanics model. Using the elastoplastic behavior of the adsorption interphase zone obtained from the present study, stress-strain relation of nanocomposites at various interfacial bonding condition and local nanotube agglomeration is predicted from nonlinear micromechanics model with and without the adsorption interphase zone. As a result, it has been found that local nanotube agglomeration is the most important design factor to maximize reinforcing effect of nanotube in elastic and plastic behavior.

Health Behavior and Attitude of Residents toward the National Health Promotion Law in Kyungsan City (지역주민과 건강행태와 국민건강증진법에 대한 인식과 태도)

  • 이관희;박재용;한창현;윤석옥
    • Korean Journal of Health Education and Promotion
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    • v.16 no.2
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    • pp.19-40
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    • 1999
  • In order to ascertain the attitudes of residents to their health and the National Health Promotion Law, surveyors interviewed 1,220 subjects, 1% of men and women in Kyungsan city, who were twenty-year-old or more. The major findings are as follows: Men and women were 48.2% and 51.8%, respectively. The recognition rate of enacting and enforcing this law is 59.2% of men and 51.3% of women. With regard to the behavioral attitude to the health in the distinction of sex and age, current smokers are 31.2% of the interviewees, 61.6% of the men and 3.3% of the women. Current drinkers are 35.1%, 59.5% of the men and 12.3% of the women, but on the other hand there is little significance in the distinction of age. The acknowledgement proportion of enacting and enforcing this law is 59.2% of male and 51.3% of female. In terms of the recognition rate of the contents according to the general characteristics of interviewees, it appears that the indication of a warning expression on a packing paper of cigarette case and a liquor bottle is 92.4% and also the designation of a smoking free area in public facilities is 94.8%. Prohibition of cigarette-sale to the teenagers who are under 19, is 96.0%. Considering these facts, the recognition rate is high. On the contrary, 48.8% is accounted for encouraging a medical check-up before marriage which is in a low position. As a result of multiple behavior as a independent educational level, marital significant variables. In case of having undergone a periodic medical examination the recognition rate was high whereas frequent exercise led to the low recognition rate. Concerning the details of the undertaking in accordance with each factor of general characteristics, the greater part of them have been appraised successfully whether it is recognized or not. On the other side, no effect got answered about the result of the undertaking subjects to general and peculiar behavior attitude towards health was in effect or not. A great majority approved of more reinforcement of legal regulation about smoking and drinking regardless of whether they perceived the details of the law of promotion of National Health Promotion Law or not. Additionally there was significant difference in reinforcing legal regulation of smoking and drinking in compliance with the attitude of the substance of this law. With regard to education, public relations and evaluation about national health through public health centers by our government, the younger and the higher in education they are, the more deficient they feel. First of all, those who were aware of the enforcement of this law as well as plenty of scarcity answered that better service of disease prevention had to be expanded than ever. In consideration of the above-stated results, the education to public health and the business of public relations should be reinforced and a practical campaign for health life should also spread out for the purpose of encouraging to practise healthy life-style.

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