• Title/Summary/Keyword: impact behaviors

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Experimental Studies for Analysing of Characteristics of Floor Impact Sound through a Scale Model with Box-frame Type Structure (벽식구조 바닥판의 중량충격음 특성 분석을 위한 축소모형의 활용)

  • Yoo, Seung-Yup;Jeon, Jin-Yong
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.9
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    • pp.805-812
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    • 2011
  • This study investigated the characteristics of heavy-weight floor impact sounds of box-frame type structure using 1:10 scale model. Ten types of floor structures(bare slabs and floating floors) were evaluated in terms of dynamic stiffness and loss factor. Floor vibrations and radiated sounds generated by simulated impact source were also measured. The results showed that the bakelite was appropriate for simulating concrete slab in the 1:10 scale model, and surface velocity and sound pressure level of concrete slab measured from the scale model showed similar tendencies with the results from in-situ in frequency domain. It was also found that dynamic behaviors of layered floor structures in the 1:10 scale model were similar to those in a real scale. Therefore, the use of 1:10 scale model would be useful for evaluating the heavy-weight floor impact sound insulation of layered floor structures when the frequency-dependent dynamic properties of each material are known.

Fracture behavior of Thixoformed 357-T5 Semi-solid Al alloys (반응고 357-T5 합금의 파괴 특성)

  • Park, C.;Kim, S.S.;Bae, M.H.;Kang, S.W.;Kwon, Y.N.;Lee, Y.S.;Lee, J.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.05a
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    • pp.65-69
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    • 2003
  • The effects of microstructural features on the fracture behaviors, including impact, high-cycle fatigue, fatigue and crack propagation, of thixoformed 357-T5 (Al-7%Si-0.6%Mg) alloy were examined. The resistance to impact and high-cycle fatigueof thixoformed 357-T5 tended to improve greatly with increasing solid volume fraction. An almost three-fold increase in impact energy value was, for example, observed with increasing solid volume fraction from 59 to 70%. The improvement in both impact and fatigue properties of thixoformed 357-75 with increasing solid volume fraction in the present study appeared to be related to the magnitude of stress concentration at the interface between primary and eutectic phase, by which the fracture process was largely influenced. Based on the fractographic and micrographic observations, the mechanism associated with the beneficial effect of high solid volume fraction in thixoformed 357-T5 alloy was discussed.

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Mechanical behaviors of concrete combined with steel and synthetic macro-fibers

  • Deng, Zongcai;Li, Jianhui
    • Computers and Concrete
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    • v.4 no.3
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    • pp.207-220
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    • 2007
  • In this paper, hybrid fibers including high elastic modulus steel fiber and low elastic modulus synthetic macro-fiber (HPP) as two elements were used as reinforcement materials in concrete. The flexural toughness, flexural impact and fracture performance of the composites were investigated systematically. Flexural impact strength was analyzed with statistic analyses method; based on ASTM and JSCE method, an improved flexural toughness evaluating method suitable for concrete with synthetic macro-fiber was proposed herein. The experimental results showed that when the total fiber volume fractions ($V_f^a$) were kept as a constant ($V_f^a=1.5%$), compared with single type of steel or HPP fibers, hybrid fibers can significantly improve the toughness, flexural impact life and fracture properties of concrete. Relative residual strength RSI', impact ductile index ${\lambda}$ and fracture energy $G_F$ of concrete combined with hybrid fibers were respectively 66-80%, 5-12 and 121-137 N/m, which indicated that the synergistic effects (or combined effects) between steel fiber and synthetic macro-fiber were good.

The Impact of Green Corporate Identity and Green Personal-Social Identification on Green Business Performance: A Case Study in Thailand

  • ONPUTTHA, Suraporn;SIRIWICHAI, Chalermporn
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.5
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    • pp.157-166
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    • 2021
  • This study aims to investigate the impact of green corporate identity and employees' green identification on green business performance of international automobile manufacturers in Thailand. It involves 400 employees from the target study area, using questionnaires to collect data from January to February 2021, with purposive and convenient sampling methods. Data analysis employed structural equation modeling (SEM). The results show that green corporate identity has a significant impact on employees' green personal-social identification and green business performance; meanwhile, employees' green social identification has a significant impact on green business performance. However, employees' green personal identification has a significant impact on green business performance only through employees' green social identification. Green corporate identity can increase the corporate' green business performance via economic, environmental and social aspects through employees' green personal-social identification. The findings suggest that green corporate communication through visual identity, employee behaviors, culture, policy products and services in response to environmental forces and drivers to create the green corporate identity is deemed to systematically work. Furthermore, the findings also suggest that employees' green identification on both personal and social levels can be a significant issue that the managers in automobile manufacturers should pay attention as well.

Study for Real-World Accident Database and Occupant Behavior Analysis in Far-Side Collisions (Far-Side 실사고 분석과 승객거동해석 연구)

  • Jaeho, Shin;Chang Min, Baek
    • Journal of Auto-vehicle Safety Association
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    • v.14 no.4
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    • pp.77-83
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    • 2022
  • Occupant behaviors and body contact with vehicle interior parts are main injury mechanism in far-side collisions. In vehicle side impact accident where the crash accident occurs on the opposite side of the vehicle from the a particular occupant, it is exposed in terms of relatively larger lateral motion to interact with the opposite side of the vehicle structure. The challenge of minimizing motions of upper body and injury risk according to a direct contact is a primary occupant protection research. This study has performed a data analysis of real-world accident database extracted from the 2016~2020 CISS database and a parametric investigation of impact angles and occupant kinematics in far-side lateral and oblique impact simulations. A detailed data analysis was conducted to reveal the relationship among the accident and injury data. Database analysis and computational far-side impact results proposed the fundamental vehicle design for safety improvement in far-side collisions.

Numerical assessment of rectangular one- and two-way RC slabs strengthened with CFRP under impact loads

  • Mohamed Emara;Ahmed Hamoda;Jong Wan Hu
    • Computers and Concrete
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    • v.31 no.3
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    • pp.173-184
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    • 2023
  • In this study, the flexural behaviors of one- and two-way reinforced concrete (RC) slabs strengthened with carbon-fiber-reinforced polymer (CFRP) strips under impact loads were investigated. The flexural strengthening of RC slabs under simulated static monotonic loads has been comprehensively studied. However, the flexural behavior of RC slabs strengthened with CFRP strips has not been investigated extensively, particularly those conducted numerically. Nonlinear three-dimensional finite element models were developed, executed, and verified against previous experimental results, producing satisfactory models with approximately 4% error. The models were extended to a parametric study, considering three geometric parameters: the slab rectangularity ratio, CFRP strip width, and CFRP strip configuration. Finally, the main results were used to derive a new formula for predicting the total deflection of RC slabs strengthened with CFRP strips under impact loads with an error of approximately 10%. The proposed equation reflected the slab rectangularity, CFRP strip width, equivalent slab stiffness, and dropped weight. Results indicated that the use of CFRP strips enhanced the overall impact performance, the wider the CFRP width, the better the enhancement. Moreover, the application of diagonally oriented CFRP strips diminished the cracking zone compared to straight strips. Additionally, the diagonal orientation of CFRP strips was more efficient for two-way slabs while the vertical orientation was found to be better in the case of one-way slabs.

Effects of Chinese tourists' beauty tour preferences and attitude toward Korean culture on beauty tour purchasing behaviors (중국 관광객의 뷰티관광 선택속성과 한국문화 친밀성이 뷰티관광 구매행동에 미치는 영향)

  • Jeong, Ha-Eun;Kim, Mi Young
    • The Research Journal of the Costume Culture
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    • v.24 no.5
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    • pp.653-669
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    • 2016
  • This study examined how Chinese tourists' beauty tour preferences and attitudes toward Korean culture impacted their purchasing behaviors, repurchasing intentions, and the likelihood that they would recommend the products and services they received. Between the 10th and 21st of June, 2016, a total of 277 questionnaires were distributed in Seoul, Busan and Daegu using SPSS 21.0. On the surveys, beauty tour preferences were divided into the following categories: human service, high quality service, convenience accessibility & cost, and facility & atmosphere. The study found that high quality service and convenience & accessibility significantly affected respondents' purchasing intentions, with high quality service showing the higher standardized beta value. Friendliness to Korean culture also had a significant impact on beauty tour purchasing intentions. Preference for human service, high quality service, and facility & atmosphere significantly affected the purchasing intentions and the likelihood o f respondent recommendations, with higher standardized beta values shown (from high est to lowest) in the preference for facility & atmosphere, and preference for human service and high quality service respectively. Concerning perceptions of beauty products, preference for quality had a significant impact on the repurchasing intentions and intentions of respondents to make recommendations, as did the respondents', friendliness toward Korean culture. This study suggests that, to be most effective, beauty tours should emphasize human service and facility & atmosphere, as well as high quality service. In addition, preference for beauty services or products, and friendliness to Korean culture must be considered.

Mukbang and Cookbang watching and dietary behavior in Korean adolescents

  • Jimin Sung;Jae-Young Hong;Jihong Kim;Jihye Jung;Seoeun Choi;Ji Yun Kang;Mi Ah Han
    • Nutrition Research and Practice
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    • v.18 no.4
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    • pp.523-533
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    • 2024
  • BACKGROUND/OBJECTIVES: Given that adolescents watch Mukbang (eating broadcast) more frequently than other age groups, interest in the potential health effects of watching Mukbang and Cookbang (cooking broadcast) is growing. This study aimed to determine the status of watching Mukbang and Cookbang among Korean adolescents and its relationship with their dietary behaviors. SUBJECTS/METHODS: We used data from the 18th Korea Youth Risk Behavior Survey, conducted in 2022 (n = 51,850). The study included the frequency of watching Mukbang and Cookbang and the self-rated impact of watching them. Dietary behaviors included consumption of the following items: fruits (≥ once a day), vegetables (≥ 3 times a day), fast foods (≥ 3 times a week), late-night snacks (≥ 3 times a week), caffeinated drinks (≥ 3 times a week), and sweet-flavored drinks (≥ 3 times a week). Furthermore, obesity, weight loss attempts during the past 30 days, body image distortion, and inappropriate methods to control weight were also included. RESULTS: Among adolescents, 70.6% watched Mukbang and Cookbang, and 13.2% watched them more than 5 times a week. Approximately 27.6% of the adolescents responded that they were influenced by watching Mukbang and Cookbang. Adolescents who frequently watched Mukbang and Cookbang consumed less vegetable and fruit; however, the likelihood of consuming fast food, late-night snacks, sugary drinks, and caffeinated drinks increased. In addition, they were more likely to attempt inappropriate weight-loss methods and become obese. Adolescents who responded that their eating habits were influenced by watching Mukbang and Cookbang were more likely to have unhealthy eating behavior compared to the group who responded that their habits were not influenced by these shows. CONCLUSION: Watching Mukbang and Cookbang is common among Korean adolescents and is associated with unhealthy dietary behaviors. Prospective studies, including broadcasting content, should evaluate the impact of Mukbang and Cookbang on health.

The Relationship between Household Income, Consumption Wants for Education, Private Education Expenses, and Old-Age Economic Preparation Behaviors in Mothers with School-Aged Children (학령기 어머니의 가계소득, 교육소비욕구 및 사교육비와 경제적 노후준비행동 간의 관계)

  • Lee, Na-Young;Jang, Yoon-Ok;Jeong, Seo-Leen
    • Journal of Family Resource Management and Policy Review
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    • v.20 no.1
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    • pp.159-182
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    • 2016
  • The purpose of this study was to investigate the relationship between household income, consumption wants for education, private education expenses, and old-age economic preparation behaviors in mothers with school-aged children. The participants in this study comprised 393 mothers living with children aged 8.19 in Daegu. All participants had wage-earning husbands. A questionnaire was used to collect the data. Factor analysis was conducted using SPSS and structural regression analysis was performed using AMOS. The main results of this study were as follows: The participants' old-age economic preparation behaviors were influenced by their household income, the proportion of private education expenditures they paid, and the perceived burden the participants had of these private education expenditures. The consumption wants for education in mothers with school-aged children had no significant impact on the proportion of private education expenditures paid by the participants. Household income, proportion of private education expenditures, and perceived burden of the private education expenditures had a direct effect on the old-age economic preparation behaviors of the participants. When the perceived burden of the private education expenditures was mediated, the consumption wants for education in mothers with school-aged children had an indirect effect on their old-age economic preparation behaviors.

The Impact of Hospital CEO Leadership Behaviors on Employees' Job Satisfaction and Intention in Korea (병원 CEO 리더십 스타일이 조직구성원의 직무만족과 이직의도에 미치는 영향Turnover)

  • Park, Jae-San
    • Health Policy and Management
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    • v.16 no.3
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    • pp.1-18
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    • 2006
  • The organizational effectiveness of hospital in various environmental fluctuations is a large and complex problem. Hospital CEO leadership characteristics may be a critical determinant of employees' job satisfaction and turnover intention. Several empirical studies on transformational leadership found that transformational leadership behaviors were positively related to workers' job satisfaction and turnover intention. Very little research related to this subject has been done in health care settings in Korea. The author explores the relationship between hospital CEO leadership style and its effect on job satisfaction and turnover intention among the all staffs of general hospital. The relationship of hospital CEO leadership style to employees' job satisfaction was investigated using the Bass's leadership paradigm of transformational and transactional leadership. The Multifactor Leadership Questionnaire(MLQ) and the index of job satisfaction and turnover intention were completed by 493 hospital employees(doctors, nurses, hospital administrators, technicians, and assistants). The findings show a similar trend to the previous studies. Hospital CEO leadership behaviors and employee outcomes were significantly correlated. Correlations showed a significant positive relationship between those hospital CEO exhibiting a transformational leadership style and the job satisfaction of their staffs. The results of multiple regression analysis indicate that the effect of charisma in transformational leadership behaviors is more higher than other variables. Transformational leadership style may be a more effective strategy and have a greater effect on staff outcomes, attitudes and behaviors. The findings of this study reveal implications for efficient hospital management and the importance of understanding relationship between hospital CEO's leadership style and subordinate behaviors in the context of CEO's desirable role and function for hospital strategy planning and future direction.