• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.4
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• pp.141-148
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• 2008

In the recent construction industry, Carbon Fiber Reinforced Polymers(CFRPs) have been highly considered as innovative strengthening materials for civil structures due to their superior material properties. This paper is to offer design data and strengthening efficiency of reinforced concrete beams strengthened with CFRP Plate. Static tests were carried out to evaluate failure modes and strengthening capacity. Displacements and strains of steel and CFRP plates were obtained and analyzed through a series of fatigue tests. Also, Those evaluated the energy dissipation. Results of the tests showed increase in strengthening ratios caused debonding failure at the end of beams. For the beams wrapped with CFRP sheets around the end of the plates, debonding failure mode that was induced from flexural cracks was indicated. Through the fatigue tests, it was observed that displacements, strains of steel and CFRP plates converged into certain values. It is also proved that the beams strengthened with CFRP plates are able to resist fatigue loading under serviceability.

• Earthquakes and Structures
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• v.27 no.3
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• pp.191-207
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• 2024

Due to the many advantages of concrete-filled double steel tube (CFDT) columns, they are highly recommended for use in heavy-load structures such as bridges, subway stations, and high-rise buildings. This study was carried out with the aim of numerically investigating and comparing the performance of CFDT columns under cyclic and seismic loads and providing innovative strengthening methods for CFDT columns. Hollow circular steel sections have been used for internal and external tubes. To make the circular CFDT columns stronger against seismic loads, stiffeners with different shapes (rectangular and T-shaped sheets) have been welded to the outside and inside tubes. The validated finite element (FE) model of the ABAQUS program is used to look into the behavior of CFDT columns numerically. Two frames of 10 and 20 floors with strengthened CFDT columns were modeled. The results showed that the use of stiffeners in the CFDT column has a significant effect on seismic performance, so that the maximum lateral load of the column is increased up to 32.74% under the effect of cyclic load. Also, the results revealed that the use of stiffeners in the columns of moderate and high-rise building frames causes a significant increase in the shear of the base and consequently the stiffness. Among the other important results that followed, it reduced the drift of floors and increased energy absorption.

• Structural Engineering and Mechanics
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• v.91 no.3
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• pp.263-277
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• 2024

The primary aim of this study is to introduce an innovative configuration for stirrup hooks in reinforced concrete beams and analyze the impact of factors such as stirrup spacing, placement, and hook lengths on the structural performance of reinforced concrete beam elements. A total of 18 specimens were produced and subjected to reversed cyclic loading, with two specimens serving as reference specimens and the remaining 16 specimens utilizing a specifically developed stirrup hook configuration. The experiment used reinforced concrete beams scaled down to half their original size. These beams were built with a shear span-to-depth ratio of 3 (a/d=3). The experimental samples were divided into two distinct groups. The first group comprises nine test specimens that consider the contribution of concrete to shear strength, while the second group consists of nine test specimens that do not consider this contribution. The preparation of reference beam specimens for both groups involved the utilization of standard hooks. The stirrup hooks in the test specimens are configured with a 90-degree angle positioned at the midpoint of the bottom section of the beam. The criteria considered in this study included the distance between hooks, hook angle, stirrup spacing, hook orientation, and hook length. In the experimental group examining the contribution of concrete on shear strength, it was noted that the stirrup hooks of both the R1 reference specimen and specific test specimens displayed indications of opening. However, when the contribution of concrete on shear strength was not considered, it was observed that none of the stirrup hooks proposed in the R0 reference specimen and test specimens showed any indications of opening. Neglecting the contribution of concrete in the assessment of shear strength yielded more favorable outcomes regarding structural robustness. The study found that the strength values obtained using the suggested alternative stirrup hook were similar to those of the reference specimens. Furthermore, all the test specimens successfully achieved the desired strengths.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.1057-1064
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• 2024

The construction industry has witnessed a concerning rise in ladder-related accidents, necessitating the implementation of stricter safety measures. Recent statistics highlight a substantial number of accidents occurring while using ladders, emphasizing the mandatory need for preventative measures. While prior research has explored computer vision-based automatic monitoring for specific aspects such as ladder stability with and without outriggers, worker height, and helmet usage, this study extends existing frameworks by introducing a rule set for co-workers. The research methodology involves training a YOLOv5 model on a comprehensive dataset to detect both the worker on the ladder and the presence of co-workers in real time. The aim is to enable smooth integration of the detector into a mobile application, serving as a portable real-time monitoring tool for safety managers. This mobile application functions as a general safety tool, considering not only conventional risk factors but also ensuring the presence of a co-worker when a worker reaches a specific height. The application offers users an intuitive interface, utilizing the device's camera to identify and verify the presence of coworkers during ladder activities. By combining computer vision technology with mobile applications, this study presents an innovative approach to ladder safety that prioritizes real-time, on-site co-worker verification, thereby significantly reducing the risk of accidents in construction environments. With an overall mean average precision (mAP) of 97.5 percent, the trained model demonstrates its effectiveness in detecting unsafe worker behavior within a construction environment.

• 한국벤처창업학회:학술대회논문집
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• 2017.08a
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• pp.1-13
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• 2017

In the era of the 4th Industrial Revolution, as the importance of creative talent became more and more important, we recognized the urgent need for start-ups to innovate new growth industries and creative talents to lead these eras.And the importance of entrepreneurship education emphasized in entrepreneurship education and the necessity of creativity competency education.However, there is a lack of research on how creativity competency education affects entrepreneurship intention for college students. Especially, research on the moderating effect of social support on the effect of entrepreneurship through education is very insufficient. The purpose of this study is to examine the effects of creativity competence education on the will of entrepreneurship and empowerment of social support. For this purpose, 393 college students were used for empirical analysis for 1 month from August 2016. As a result of this study, the ability of communicative communication and creative problem solving had a positive effect on self - efficacy. On the other hand, innovative work behavior abilities did not directly affect self-efficacy. In addition, creative problem solving ability and innovative work behavior ability had a positive effect on the will to start up. Collaborative communication skills, however, did not directly affect the willingness to start a business. Self - efficacy has a positive effect on the will of founding. Finally, the moderating effect of social support between self-efficacy and willingness to work was not directly affected. The implication of this study is that the effect of the creativity competency education on college students has a positive effect on the self - efficacy of self and the positive influence on the will to start up. The results of this study are as follows. First, it is found that the influence of social support (parental support) is not positively influenced by the control effect of the parents. In the case of college students, As well as the need to do so. Therefore, in order to further increase the willingness of young people to establish a university in the university, it is necessary to provide education and programs not only for direct education for college students, but also for improving the understanding of the talents and entrepreneurship required by the age of their parents.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.6
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• pp.25-39
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• 2017

The role of traditional universities has been emphasized as a career path to advance into society. Recently, it has become a new paradigm of university education by emphasizing entrepreneurship as a career aspect. While entrepreneurship education is constantly expanding for college students, relatively few young people choose to start their own business. Despite the fact that the government is continuing to expand the university's entrepreneurship education, there are very few achievements that lead to actual entrepreneurship and student start-up There is still a lack of research on ways to cultivate creative talents and increase practical entrepreneurial intention. The results of this study are as follows: First, the effects of creativity competency education on self-efficacy and entrepreneurial intention were analyzed. The effect of self-efficacy on the entrepreneurial intention. Finally This study examined the effects of social support (parent support) between self-efficacy and entrepreneurial intention. This study used 393 samples in August 2016 for university students who received entrepreneurship education. The results showed that the ability of communicative communication and creative problem solving had a positive effect on self-efficacy. On the other hand, innovative work behavior abilities did not directly affect self-efficacy. In addition, creative problem solving ability and innovative work behavior ability had a positive effect on the entrepreneurial intention. On the other hand, the ability to communicate in a collaborative manner has no direct effect on the entrepreneurial intention. In addition, self-efficacy has a positive effect on the entrepreneurial intention. Finally, the adjustment effect of social support (parent support) between self-efficacy and entrepreneurial intention has no effect. The implications of this study are empirically verified the effectiveness of creativity capacity through entrepreneurship education and the result of meaningful research that the social support through cooperation of parents is indispensable in order to increase the actual starting will of college students. Therefore, universities need to establish entrepreneurship education programs for their parents in order to increase the willingness of college students to start-up. This study can be used as a meaningful basic data for establishing policy for student start - up and suggesting the right direction of entrepreneurship education.

• Korean Business Review
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• v.12
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• pp.161-187
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• 1999

Organ(1988) has suggested that OCB should be considered an important component of job performance because citizenship behaviors are part of the spontaneous and innovative behaviors. Also it has been suggested that organizational characteristics may potentially explain many organizational behavior outcome variables(Hackman & Oldham, 1980). In recent years there has been a resurgence of interest in the validity of personality measures as a moderator between many variables and organizational outcome variables. This is largely due to the facts that first personality is difficult to control for promoting many organizational outcomes and next many researchers have found the moderating effects of personality(Brief & Aldag, 1975; Wanous, 1974). The purpose of this research is to test the moderating effects of tenure and growth needs on the relationships between organizational characteristics and OCB. To assess the moderating effects, the hierarchical regression procedures outlined by Cohen and Cohen(1983) were followed. On the basis of data from 698 teachers in Wonju province, results indicated that job variety has more impacts than any other independent variable on OCB like other studies. It is found that job variety and job identity have more impacts on courtesy and altruism in lower growth needs group than in higher growth needs group. Also it is resulted that job importance and autonomy have more impacts on sportsmanship in higher growth needs group than in lower growth needs group.

• Nutrition Research and Practice
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• v.11 no.3
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• pp.247-256
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• 2017

BACKGROUND/OBJECTIVES: Easy access to intervention and support for certain behaviors is important for obesity prevention and management. The available technology such as smartphone applications can be used for intervention regarding healthy food choices for obesity prevention and management in elementary-school students. The transtheoretical model (TTM) is comprised of stages and processes of change and can be adopted to tailored education for behavioral change. This study aims to develop TTM-based nutrition contents for mobile applications intended to change eating behaviors related to weight gain in young children. SUBJECTS/METHODS: A synthesized algorithm for tailored nutrition messages was developed according to the intake status of six food groups (vegetables, fruits, sugar-sweetened beverages, fast food and instant food, snacks, and late-night snacks), decision to make dietary behavioral changes, and self-confidence in dietary behavioral changes. The messages in this study were developed from December 2014 to April 2015. After the validity evaluation of the contents through expert consultation, tailored nutrition information messages and educational contents were developed based on the TTM. RESULTS: Based on the TTM, stages of subjects are determined by their current intake status, decision to make dietary behavioral changes, and self-confidence in dietary behavioral changes. Three versions of tailored nutrition messages at each TTM stage were developed so as to not send the same messages for three weeks at most, and visual materials such as figures and tables were developed to provide additional nutritional information. Finally, 3,276 tailored nutrition messages and 60 nutrition contents for applications were developed. CONCLUSIONS: Smartphone applications may be an innovative medium to deliver interventions for eating behavior changes directly to individuals with favorable cost-effectiveness. In addition, using the TTM for tailored nutrition education for healthy eating is an effective approach.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.875-888
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• 2013

The researches have recently progressed toward the use of the superelastic shape memory alloys (SMAs) to develop new smart control systems that reduce permanent deformation occurring due to severe earthquake events and that automatically recover original configuration. The superelastic SMA materials are unique metallic alloys that can return to undeformed shape without additional heat treatments only after the removal of applied loads. Once the superelastic SMA materials are thus installed at the place where large deformations are likely to intensively occur, the structural system can make the best use of recentering capabilities. Therefore, this study is intended to propose new buckling-restrained braced frames (BRBFs) with superelastic SMA bracing systems. In order to verify the performance of such bracing systems, 6-story braced frame buildings were designed in accordance with the current design specifications and then nonlinear dynamic analyses were performed at 2D frame model by using seismic hazard ground motions. Based on the analysis results, BRBFs with innovative SMA bracing systems are compared to those with conventional steel bracing systems in terms of peak and residual inter-story drifts. Finally, the analysis results show that new SMA bracing systems are very effective to reduce the residual inter-story drifts.

• Journal of the Korean GEO-environmental Society
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• v.7 no.6
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• pp.13-22
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• 2006

The geotextile have been used in filtration and drainage for over 30 years in many applications of civil and environmental projects. Geotextile tube is compound technology of filtration and drainage property of geotextile. Geotextile have been used for various types of containers, such as small hand-filled sandbags, 3-dimensional fabric forms for concrete paste, large soil and aggregate filled geotextile gabion, prefabricated hydraulically filled containers, and other innovative systems involving containment of soils using geotextile. They are hydraulically filled with dredged materials. It have been applied in coastal protection and scour protection, dewatering method of slurry, and isolation of contaminated material. Recently, geotextile tube technology is no longer alternative construction technique but suitable desired solution. This paper presents the behavior of geotextile tube composite structure by 2-D limit equilibrium and plane strain analysis. 2-D limit equilibrium analysis was performed to evaluate the stability of geotextile tube composite structure for the lateral load and also the plane strain analysis was conducted to determine the design and construction factors. Based on the results of this paper, the three types of geotextile tube composite structure is stable. And the optimum tensile strength of geotextile is 151kN/m and maximum pumping pressure is 22.7kN/m.