• 한국소음진동공학회논문집
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• 제26권2호
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• pp.130-140
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• 2016

Floating floor is most commonly used at apartment houses in Korea for thermal insulation and reducing impact noise. But it in proven that the floating floor is not effective for reducing the floor impact noise in low frequency range. In most cases, impact sound pressure level under 63 Hz frequency band were actually increased by the resonance of resilient material, lightweight concrete and the finishing mortar installed on it. In this paper, an integrated floor system consist of 70 mm light weight concrete and 40 mm finishing mortar successively installed on the concrete slab was suggested to avoid the resonance. Integrated floor system increases total flexural stiffness and mass per unit area. The natural frequencies of first and second vibration mode were increased and acceleration response and floor impact sound level was decreased in all measurement range.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.240-244
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• 2005

In this study a simple model is developed that predicts impact damage in a composite laminate using an analytical model. The model uses a non-linear approximation method (Rayleigh-Ritz) and the large deflection plate theory to predict the number of failed plies and damage area in a quasi-isotropic composite circular plate (axisymmetric problem) due to a point impact load at its centre. It is assumed that the deformation due to a static transverse load is similar to that occurred in a low velocity impact. It is found that the model, despite its simplicity, is in good agreement with FEM predictions and experimental data for the deflection of the composite plate and gives a good estimate of the number of failed plies due to fibre breakage. The predicted damage zone could be used with a fracture mechanics model developed by the second investigator and co-workers to calculate the compression after impact strength of such laminates. This approach could save significant running time when compared to FEM solutions.

• Journal of Mechanical Science and Technology
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• 제19권4호
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• pp.947-957
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• 2005

In this study a simple model is developed that predicts impact damage in a composite laminate avoiding the need of the time-consuming dynamic finite element method (FEM). The analytical model uses a non-linear approximation method (Rayleigh-Ritz) and the large deflection plate theory to predict the number of failed plies and damage area in a quasi-isotropic composite circular plate (axisymmetric problem) due to a point impact load at its centre. It is assumed that the deformation due to a static transverse load is similar to that oc curred in a low velocity impact. It is found that the model, despite its simplicity, is in good agreement with FEM predictions and experimental data for the deflection of the composite plate and gives a good estimate of the number of failed plies due to fibre breakage. The predicted damage zone could be used with a fracture mechanics model developed by the second investigator and co-workers to calculate the compression after impact strength of such laminates. This approach could save significant running time when compared to FEM solutions.

• 디지털산업정보학회논문지
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• 제10권3호
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• pp.285-296
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• 2014

Recently, the use of Smartphones has been widespread and changed our lives positively. Smartphones which are called as PC in the hand and spread general people rapidly are becoming a medium to use generally various functions such as internet, work, multimedia, etc. beyond the simple function of telephone communication in the past. However, the excessive use of Smartphones has also produced many side effects. The purpose of this study is to examine the Smartphone Addiction on Daily Life Impact. This model tests various theoretical research hypotheses relating to Self-Esteem, Enjoyment, Flow, Social Impact, Smartphone Addiction and Daily life impact. The proposed model is analyzed to target 299 University Students and Smart Partial Least Square(PLS) 2.0 have been utilized for deriving the study results. The Result of Hypothesis testing are as follows. First, Self-Esteem negatively influence Smartphone Addiction. Second, Enjoyment, Flow and Social Impact positively influence Smartphone Addiction. Third, Smartphone Addiction positively influence Daily Life impact. This Research makes a basic research for smart phone addiction papers that will be investigated a lot in the future.

• 환경영향평가
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• 제27권4호
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• pp.345-352
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• 2018

기후변화 적응 주류화를 위하여 세 가지 기후변화영향평가 시행 방안을 검토하였다. 첫째, 신법 마련 및 개별 시행, 둘째, 신법 마련 및 환경영향평가 틀 내 제도 시행, 셋째, 기존 환경영향평가 틀 내 시행하는 것이다. 이 논문에서는 세 가지 방안의 내용, 장 단점을 분석하였다. 그리고 신법 하에서 제도를 개별 시행할 경우의 개략적인 평가 내용과 환경영향평가 틀 내에서 시행하고자 할 경우 관련 법률, 규정개정(안)을 제안하였다.

• The Journal of Asian Finance, Economics and Business
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• 제7권10호
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• pp.555-569
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• 2020

This study examines the impact of corporate tax, a fiscal measure along with trade liberalization and research and development on total factor productivity for a panel of 153 industrial firms listed on the Pakistan Stock Exchange over the period 1997-2017. For empirical analysis, we employ the system generalized method of moment estimator. In the first step, we estimate industrial production function and the results reveal that raw material, industrial labour force and energy play vital role in enhancing industrial production. Whereas, industrial capital exerts negative impact on industrial output. We also measured total factor productivity using the production elasticities. In the second step, we examine the impact of corporate tax, trade liberalization and research and development on total factor productivity. The results indicate that higher level of corporate tax exerts negative impact on total factor productivity. The findings reveal that higher corporate taxation discourages industrial firms to undertake research and development thereby exerting adverse impact on total factor productivity of firms. The impact of trade liberalization proxied by average tariff is positive while customs duty and sales tax negatively impact firm-level total factor productivity. These findings provide useful insights for managers, investors and policy makers in Pakistan.

• Structural Engineering and Mechanics
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• 제82권1호
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• pp.81-92
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• 2022

Ultra-high performance fiber reinforced concrete (UHPFRC) is a composite building material with high ductility, fatigue resistance, fracture toughness, durability, and energy absorption capacity. The aim of this study is to develop a nonlinear finite element model that can simulate the response of the UHPFRC beam exposed to impact loads. A nonlinear finite element model was developed in ABAQUS to simulate the real response of UHPFRC beams. The numerical results showed that the model was highly successful to capture the experimental results of selected beams from the literature. A parametric study was carried out to investigate the effects of reinforcement ratio and impact velocity on the response of the UHPFRC beam in terms of midpoint displacement, impact load value, and residual load-carrying capacity. In the parametric study, the nonlinear analysis was performed in two steps for 12 different finite element models. In the first step, dynamic analysis was performed to monitor the response of the UHPFRC beam under impact loads. In the second step, static analysis was conducted to determine the residual load-carrying capacity of the beams. The parametric study has shown that the reinforcement ratio and the impact velocity affect maximum and residual displacement value substantially.

• 아태비즈니스연구
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• 제14권3호
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• pp.221-240
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• 2023

Purpose - This paper investigates how business cycle impacts on corporate credit spreads since global financial crisis. Furthermore, it tests how the impact changes by the phase of the cycle. Design/methodology/approach - This study collected dataset from Barclays Global Aggregate Bond Index through the Bloomberg. It conducted multi-regression analysis by projecting business cycle using Hodrick-Prescott filtering and various cyclical variables, while ran dynamic analysis of 5-variable Vector Error Correction Model to confirm the robustness of the test. Findings - First, it proves to be statistically significant that corporate credit spreads have moved countercyclicaly since the crisis. Second, It indicates that the corporate credit spread's countercyclicality to the macroeconomic changes works symmetrically by the phase of the cycle. Third, the VECM supports that business cycle's impact on the spreads maintains more sustainably than other explanatory variable does in the model. Research implications or Originality - It becomes more appealing to accurately measure the real economic impact on corporate credit spreads as the interaction between credit and business cycle deepens. The economic impact on the spreads works symmetrically by boom and bust, which implies that the market stress could impact as another negative driver during the bust. Finally, the business cycle's sustainable impact on the spreads supports the fact that the economic recovery is the key driver for the resilience of credit cycle.

• International Journal of Advanced Culture Technology
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• 제12권1호
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• pp.60-74
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• 2024

Due to the relative lack of concerns and research on organizational career development in startups, we study aimed to reveal the impact of shared leadership in startups on organizational career development through organizational commitment. The research method was an online survey targeting 200 startup members from April 11 to April 28, 2023, and a total of 195 copies were used in the final analysis. As a result of the study, first, among the shared leadership of startups, development and mentoring were found to have a positive impact on emotional commitment. Second, among the shared leadership of startups, planning and organizing, support and empathy were found to have a positive impact on continuous commitment. Third, planning and organizing, support and empathy had a positive impact on normative commitment. Third, among startups' shared leadership, planning and organizing, support and empthy had a positive impact on normative commitment. Fourth, emotional and continuous commitment were found to have a positive impact on improving career goals in organizational career growth. Fifth, emotional and continuous and normative commitment were each found to have a positive influence on the development of professional abilities in organizational career development. Lastly, emotional, continuous and normative commitment were all found to have a positive influence on the speed of promotion in organizational career growth. As a result, it is expected that the results of this study will be able to suggest shared leadership policy directions and goals for startups.

• 환경영향평가
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• 제29권2호
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• pp.132-143
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• 2020

본 연구는 그동안 지자체에서 시행해오던 환경영향평가 제도 현황 및 운영실태에 대한 분석을 통해 지자체 환경영향평가 운영체계의 성과와 한계를 파악하고 이를 개선하기 위한 정책 방안을 제시하는 것을 목적으로 한다. 연구 과제 수행 방법으로는 행정분권화에 따른 지자체 환경영향평가의 긍정적·부정적 영향에 대한 선행 연구 고찰을 바탕으로 서울시, 제주도, 부산시, 대전시 등 주요 지자체들의 환경영향평가 조례 현황을 분석하고 해당 지자체 담당 공무원들과의 심층 인터뷰를 통해 협의 및 운영실태, 그리고 제반 문제점들을 파악하고자 하였다. 분석 결과, 지자체 환경영향평가제도 시행의 주요 성과는 지역 특성에 부합하는 평가대상 및 항목의 선정과 지속적 평가관리가 가능하고, 자체적인 사후조사 관리 등을 통해 평가 협의 후 지자체의 모니터링 및 관리 감독 기능이 강화될 수 있다는 것이었다. 주요 문제점으로는 지자체의 장이 사업 승인권과 환경영향평가 협의권을 동시에 갖게 됨으로써 발생하는 의사결정과정의 문제, 환경평가 부서와 타 부서와의 업무협력 시스템이 유기적으로 작동하지 못하는 문제, 평가담당 부서의 조직과 인력의 열악함, 그리고 심의위원 전문인력 풀 확보의 어려움과 비효율적 운영시스템 등이 도출되었다. 또한, 평가 대상사업 및 범위의 조율 과정에서 중복규제 가능성의 문제가 빈번하게 제기된다는 것도 지자체 환경영향평가 제도 이행상의 주요 문제로 제기되었다.