시스템 사고를 활용한 건축생산성향상 전략 수립에 관한 연구

김봉식,이윤선,홍정석,김재준,Kim, Bong-Sik,Lee, Yoon-Sun,Hong, Jung-Seok,Kim, Jae-Jun 한국건설관리학회 2008 건설관리 : 한국건설관리학회 학회지 Vol.9 No.6

최근 건설업은 국내 경기침체 및 규제강화로 인하여 위축되어 있다. 이를 해결하려는 방안으로 생산성의 향상에 대한 요구가 증하고 있으나, 제조업 등 다른 산업의 생산성향상을 위한 노력에 비하여 건설업은 미약한 실정이다. 하지만 건설업의 지역 환경조건, 다양한 공종 등 생산성에 큰 영향을 미칠 수 있는 요인이 많다는 것을 봤을 때 이러한 요인들의 특성을 이해하고, 상황에 맞게 활용 및 제어할 수 있다면 건축생산성은 향상 될 수 있을 것이다. 이에 본 연구는 건축 생산성 향상을 위해 설계 및 시공자의 시각으로 생산성 요인을 도출하여 그들의 관계 및 문제점을 시스템 사고를 통하여 분석하고 생산성향상을 위한 기회와 위협요인, 내 외부강점을 분석하여 생산성 향상 전략을 수립하였다. Recently, Construction market is contracted by economic slump and regulation. As the solution of this plan, construction productivity is gathering strength. However, the study on the productivity in construction section is insufficient until now. Construction section has many factor about productivity. The point of this study, we analysis the factor of construction productivity improvement and relationship with system thinking. And we show the strategy of construction productivity improvement.

FFS모드 LCD의 투과율 향상을 위한 전극 구조 개선

김봉식,오현민,박우상,Kim, Bong-Sik,Oh, Hyun-Min,Park, Woo-Sang 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.4

In this study, we proposed a novel electrode structure for the fringe field switching (FFS) mode LCD and performed a three-dimensional computer simulation to calculate the optical transmittance for the new structure. In the simulation Erickson-leslie equation and Berreman $4{\times}4$ matrix were used for obtaining the director distribution profiles of liquid crystal molecules and the electro-optical characteristics, respectively. Considering the complexity of the motional equation of the liquid crystal molecules, FDM (finite difference method) was used as a numerical method. From the results, We revealed that the light transmission of the newly designed pixel structure is expended to the edge of the pixel electrode. We also confirmed that the light transmittance increased more than 13% compared to that of the conventional electrode structure.

TN-LCD 광학보상을 위한 Biaxial Film의 이론적 해석

김봉식,강춘기,박우상,Kim, Bong-Sik,Kang, Choon-Ky,Park, Woo-Sang 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.3

In this paper, we have studied on the optimal design of the optical compensation film for the TN-LCDs. To have wide viewing angle panels, several methods such as multi-domain method, optical path method, and phase compensation method have been proposed. Among these methods, this paper focused on the phase compensation method. In the phase compensation method, the phase retardation generated from the optical birefringence for the off-axis incident is compensated by using optical films with refractive anisotropy. To compensate the phase retardation of the TN-LCDs, we have proposed design concept for the biaxial optical films and analyzed the optical performance for the proposed structures. The calculation of the dynamic motion of the liquid crystals was based on the Ericksen-Leslie theory and the optical performance of the TN-LCD was calculated from the Extended Jones Matrix Method. From the results, we have confirmed that the optical characteristics of the TN-LCDs with the biaxial films have been improved considerably compared with the TN-LCDs compensated by the combination of the uniaxial films.

다구찌 실험계획법을 이용한 액정 전계 프레넬 렌즈의 최적 설계

김봉식,김종운,박우상,Kim, Bong-Sik,Kim, Jong-Woon,Park, Woo-Sang 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.3

A rigorous electro-optical simulation and ray tracing for an electric field driven liquid crystal Fresnel lens was proposed to obtain design parameters of the electrode pattern of the Fresnel lens. The optimal design was carried out using Taguchi's experimental method for 17.1"($368{\times}229.5$ mm) wide LCD panels with 9 views. For the calculation of the distribution of liquid crystal molecules and the optical transmission of the panel, finite difference method and extended Jones matrix method were used to deal effectively with highly nonlinear and complicated motional equations of the liquid crystal molecules and to obtain the oblique transmission characteristics of the LCD panel. As simulation results, the optimal lengths of the 3 electrodes of the Fresnel lens are 4.0 ${\mu}m$, 30 ${\mu}m$ and 83 ${\mu}m$, respectively, and the locations of the second and third electrodes are 32.9-33.0 ${\mu}m$ and 45.9-46.0 ${\mu}m$, respectively. The optimal applied voltage of the 3 electrodes are found to be 5.75 V, 7.80 V and 11.9 V, respectively.

렌티큘러 렌즈 기반 3차원 디스플레이 장치의 광학적 해석방법

김봉식,김건우,이길훈,박우상,Kim, Bong-Sik,Kim, Keon-Woo,Lee, Kil-Hoon,Park, Woo-Sang 한국전기전자재료학회 2013 전기전자재료학회논문지 Vol.26 No.7

We propose a generic method to calculate the optical functionalities of a 3D display with a lenticular lens array. In the present work, based on the geometrical optics, it is designed considering the specifications of the display panel. For the effective simulation, we first calculate the optical functionalities of a single cylindrical lens and, by comparing with the results obtained from the conventional geometrical optics, confirm the validity of the present method. Afterwards, we obtain the full distribution of the light intensity at an optimum viewing distance by expanding the results of the single lens to the horizontal plane of the display panel. From these results, we finally confirm whether the 3D images are realized or not in the system.

유한광선추적을 이용한 렌티큘러 렌즈 기반 3차원 디스플레이 장치의 해석

김봉식,김건우,최다신,박우상,Kim, Bong-Sik,Kim, Keon-Woo,Choi, Da-Shin,Park, Woo-Sang 한국전기전자재료학회 2014 전기전자재료학회논문지 Vol.27 No.3

We propose an analysis method of an autostereoscopic display system with lenticular lens array using finite ray-tracing method that is verified by the geometrical optics. In the present work, we adopt the cylinder equation for the mathematical expression of the lenticular lens. For the calculation of the direction cosine of the transmitted ray, we first calculate the refracting point at bottom of the lens and the direction cosine of the incident ray that propagating through the lens by the Snell's law, and then apply to finite ray-tracing method. Finally, we obtain the simulation results for the intensity distribution of the ray at optimal viewing distance. From these results, we confirm the realization of 3D image that exists separately according to the viewing position at an optimal viewing distance.

3차원 영상출력을 위한 ELC 렌즈의 기하광학적 해석 방법 및 최적 설계

김봉식,김건우,백승조,박우상,Kim, Bong-Sik,Kim, Keon-Woo,Baik, Seung-Jo,Park, Woo-Sang 한국전기전자재료학회 2013 전기전자재료학회논문지 Vol.26 No.6

In this paper, a novel method based on geometrical optics is proposed to calculate the optical characteristics of an electric field driven liquid crystal (ELC) lens. For an optimally designed ELC lens, effective refractive index is calculated and then ray tracing is carried out using Huygens' principle. From the results, the intensity distribution at the optimum viewing distance (OVD) is obtained. To confirm the validity of our work, the result is compared with that calculated by the extended Jones matrix method (EJMM). As a result, it turns out that the novel method provides more simple and rigorous simulation results than the EJMM.

전파사용료 징수 법제도 현황 및 개선방안 연구

김봉식 ( Bong Sik Kim ) 한남대학교 과학기술법연구소 2009 과학기술법연구 Vol.15 No.2

These days, the efficient use of spectrum resources becomes important in the spectrum management policy. In regard of the issue, a number of measures including the introduction of market-based policy, the application of shared technologies, and the reallocation of spectrum resources are under consideration. Among these diverse measures, spectrum usage fee is regarded as an important means for encouraging efficient spectrum use. In Korea, the economic value of spectrum is reflected on spectrum licence fee and spectrum usage fee. It is recognized that those methods encourage the optimal use of spectrum resources while preventing excessive or insufficient spectrum use. Spectrum usage fee is a kind of spectrum management fee levied in accordance with spectrum use with an aim of encouraging efficient use of spectrum, the national asset. As such, spectrum usage fee differs from spectrum licence fee, in that the latter aims to retrieve the economic value of spectrum. However, in the Radio Waves Act, spectrum usage fee can be confused with spectrum auction. Furthermore, the detailed articles are not clear, hindering efficient operation and management of the system. Accordingly, there is a need to amend the related acts and decrees. Given Korea proactively takes the introduction and implementation of spectrum auction into consideration, it is very crucial to provide a clear definition of spectrum usage fee and spectrum licence fee as well as to set the direction of the related acts and decrees. With an aim of analyzing the ways of levying spectrum usage fee from the perspective of spectrum administration, the Study looks into the history and related legal framework and issues of spectrum usage fee. In addition, the Study identifies how to improve the environment, e.g., legal framework, by making analysis on the problems spectrum usage fee bears as well as their reasons. In this regard, Chapter 2 summarizes changes in spectrum administration we are facing as spectrum management environment changes. Chapter 3 looks into the legal framework for spectrum usage fee in Korea and other countries; and Chapter 4 identifies how to improve the environment by analyzing the challenges and problems in the current legal framework.

국가기획에 있어서 자율의 중요성

김봉식 ( Bong - Sik Kim ) 한국행정학회 1971 韓國行政學報 Vol.5 No.-

일본의 전쟁책임론

김봉식(Kim, Bong-Sik) 계명대학교 국제학연구소 1999 국제학논총 Vol.3 No.-