• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.610-614
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• 2008

In 2005, the revision of the Private Investment Law made the private investment objectives to extend a new area, such as institute and well-fare, military facilities by BTL(Build-Transfer-Lease). This revison will cause budget extension from 1.3 trillion to 1.6 trillion in military facilities BTL project Therefore, it is necessary to analyze the general problem of BTL and its cases. And then to be successful project, the problems must be improved. This study was focused on the improvement of regulations and analyzed the general problem from previous studies and the military projects. And then it conducted survey to soldiers for severity and performance. Finally it suggested the improvement of regulations of military facilities in BTL scheme from FGI.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.3
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• pp.21-32
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• 1992

Numerical solutions are presented for solving the free surface flow created by a three-dimensional body moving beneath the free surface with constant velocity at an angle of attack. The solution is obtained using a panel method based on the perturbation potential, which employs Havelock sources and normal dipoles distributed on the body surface and Havelock normal dipoles in the wake downstream of the trailing edge. A pressure Kutta condition with an iterative solution procedure is implemented to satisfy equal pressure condition on the upper and lower surfaces at the trailing edge. Numerical calculation examples in the present paper include an ellipsoid at zero angle of attack, a rectangular planform wing at a small angle of attack in the limit of zero Froude number and then free surface flows and hydrodynamic forces acting on the submerged spheroid and parabolic strut are calculated. Discussions are made about the validity of the present method.

• Journal of Global Scholars of Marketing Science
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• v.11
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• pp.129-146
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• 2003

This study explores whether a NBD type of model can be applied to characterize the underlying frequency distribution of online consumer's visit behavior. In this study, the following two research questions are addressed: (1) How can we characterize the underlying distribution pattern(s) of the number of repeat i i visits to a site? (2) How can consumer's Internet usages and his/her demographics affect the average number of visits to the site? Through the empirical investigation, this study found that NBD models are directly applicable to characterize the underlying distribution of visit frequency on the Internet. Furthermore, this study addresses some managerial implications for understanding how site visits are determined. Especially this study highlights the relationship between repeated visits and the visitors' Internet Usages and demographics. The proposed models are estimated and validated by online panel data that covers more than 1000 different sites and has 800,000 observations.

• Korean Journal of Social Welfare Studies
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• no.37
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• pp.171-197
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• 2008

This study focuses on the following question; self-supporting training program increases participants' income compare to non-participants who have similar characteristics. This question is based on counterfactual assumption. In other words, this study concentrates on what the outcomes would have been if the participants were to be absent. This study adopts a quasi-experimental design. To overcome previous study's methodological weaknesses, especially selection bias, I applied matching procedure based on a propensity-score matching. Matching process was performed by using 'MatchIt' software. The major findings are as follows From Least Squares Regression analysis, I found the poor's income are significantly different according to age, pre-intervention earning, material status, and participation of training. Since the poor have homogeneous education level, education variable was not statistically significant. From the Simulation Quantities of Interest analysis, I also found that treatment group's expected incomes are lower than control's expected incomes. In other words, participation of training has a negative effect on the participants' earnings.

• Economic Analysis
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• v.25 no.3
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• pp.1-29
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• 2019

This paper examines the impact of a dual labor market structure on labor productivity using unbalanced panel data from 29 OECD member countries between 1990 and 2015. By applying a variety of regression models on the panel data (e.g., a pooled regression, a fixed effects model and a GMM), we explore how changes in worker-type composition among temporary, permanent and self-employed workers contribute to productivity growth. While it appears that our results differ slightly, depending on the econometric models, overall an increase in the share of permanent workers leads to a relatively higher increase in productivity growth. On the other hand, it is also seen that the effects of the share of temporary workers on labor productivity are considerably lower than that of permanent and self-employed workers. To sum it up, our findings indicate that an increase in temporary workers could have an adverse effect on labor productivity.

• Journal of Industrial Convergence
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• v.21 no.8
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• pp.119-127
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• 2023

This study was conducted to investigate the structural relationship between depression, self-esteem, and social withdrawal that affect academic helplessness in adolescents. The study sample was 2,265 first-year students of high school in the fourth year (2021) data from the Korean Children and Youth Panel Survey 2018. In this study, data were analyzed by a structural equation model based on the partial least squares method using SmartPLS 3.0. Results indicated that depression and social withdrawal had a significant positive effect on adolescents' academic helplessness, and self-esteem had a significant negative effect. In addition, social withdrawal had a significant positive mediating effect on the relationship between depression and academic helplessness. Therefore, it is required strategies that consider the relationship between depression, self-esteem, and social withdrawal to approach adolescents' academic helplessness.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.964-968
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• 2007

A helmholtz resonator has been widely used for the purpose of suppressing low frequency noises propagated from various heat and fluid machineries. However, the resonator has demerits that the absorption bandwidth at resonance frequency is very small and a large cavity is necessary. In order to overcome these problems, in this paper, a resonator with perforated panels at the neck and/or in the cavity is proposed. The absorption performances of resonators are measured by two-microphone method and are estimated by transfer matrix method. The experimentally measured values of normal absorption coefficients are agreed well with the corresponding values from the transfer matrix method. By introducing perforated panels at the neck of a resonator, it is shown that the absorption performances and bandwidth have a significant improvement.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1415-1418
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• 2007

When a high voltage COS fuse becomes a short circuit by the over current, the impulse noise over 150 dB(A) with the strong pulse jet is radiated from the COS fuse of an electric transformer. For the purpose of the impulse noise reduction, in this study, a reactive type silencer with perforated panels are considered. The transmission loss of the silencer are calculated by transfer matrix method. The effect of the porosity, the distance between panels, and the number of perforated panel on the sound transmission loss is investigated and discussed.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.211-214
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• 2004

이륙과 음속 통과시 랜덤진동형태의 음향/진동환경에 노출되는 위성체의 음향/진동시험은 시제품을 완성한 후에 슨1행되므로 않은 시행착오를 겪거나, 과다한 안전계수를 사용하여 불필요한 무게증가 등의 문제점을 가지고 있다. 이러한 문제점을 극복하기 위하여 통계적 에너지 해석법 (Statistical Energy Analysis)을 이용한 선행 해석이 필요하다. 본 연구에서는 KOMPSAT-1 (Korea Multi-Purpose Satellite-1) 위성체의 SDM (Structural Dynamic Model)에 대하여 SEA 해석을 수행하였다. 감쇠 손실 인자 (Damping Loss Ffactor)는 단판을 분리하여, 연성 손실 인자(Coupling Loss Factor)는 SDM모델 하부의 두 샌드위치 패널을 분리하여 실험적으로 산정하였다.

• The Korean Journal of Financial Studies
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• v.4 no.1
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• pp.39-71
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• 1998

본 연구는 중소기업의 자금흐름특성과 기타 재무특성이 대기업의 그것과 어떤 차이를 갖는가를 살펴보고, 중소기업의 재무경쟁력을 규명하는데 그 목적을 두고 있다. 본 연구에서는 차입시장에서의 재무경쟁력은 실질유효이자율과 대출효율성계수를 기준으로 하였으며, 주식시장에서의 재무경쟁력은 자기자본비용과 주당 EVA를 기준으로 하였다. 그리고 본 연구에서는 연구목적을 달성하기 위해 MANOVA검정과 패널 자료를 이용한 일반화 최소자승법을 사용하였다. 중소기업의 단기 운전자금 사정은 대기업에 비해 열악하며, 재무경쟁력 역시 뒤떨어지는 것으로 나타났다. 다시 말해서 중소기업의 영업수익성은 대기업에 비해 오히려 좋으나, 차입시장 및 주식시장에서의 재무경쟁력은 상대적으로 낮은 것으로 밝혀졌다. 중소기업의 차입시장에서의 재무경쟁력을 결정하는 요인으로는 재무위험(-), 영업수익성(+), 유동성(+), 담보력(+) 등이 있었다. 그리고 중소기업의 주식시장에서의 재무경쟁력을 결정하는 요인으로는 재무위험(-), 영업위험(-), 영업수익성(+), 유동성(+), 성장성(+)등이 있었다.