The effect of parameters on the consequence of the flash fire accident by the release of heavy gas(in this study, xylene vapor) was analyzed. Simulation results showed that the distance with the lower flammable limit(XLFL) was increased with the increase of the release hole diameter. For the case of the elevated release, XLFL was increased with the increase of the wind speed and the release height, but XLFL was not affected by the wind speed for the release on the ground level. Therefore, the accident in the elevated release was more dangerous than the release on the ground level. In this condition, the release height had more effect on XLFL at the night time than the daytime and in the urban area than the rural area.

본 연구에서는 침지형 MBR 공정에서 인제거를 위해 주입되는 응집제가 분리막의 여과성능에 미치는 영향을 알아보고자 하였고, 침지형 MBR에서 분리막 표면의 오염을 방지하기 위해 연속적으로 행하는 폭기가 응집 플록에 미치는 영향을 조사하고자 하였다. 이를 위해 MBR공정의 폭기조 슬러지를 채취하여 jar-test를 실시한 결과와 비교하였다. 실험 결과는 플록 크기와 슬러지 탈수성의 지표로서 비여과저항(SRF, Specific Resistance of Filtration)을 측정하여 비교하였다. 응집제 주입량이 증가할수록 10μm 수식 이미지 이하의 플록의 비율이 저감되었으며 탈수성이 증가하였다. 그러나 jar-test 결과와 비교하였을 때, 폭기의 전단력에 의해 그 효과가 저감된 것을 알 수 있었다. 응집제를 주입한 경우 주입하지 않은 경우보다 운전지속시간이 연장되었다 운전지속시간이 응집제 주입량에 비례하여 증가하지는 않았는데, 이는 연속적인 폭기의 전단력으로 인해 10μm 수식 이미지 이하의 입자가 충분히 저감되지 않았기 때문인 것으로 생각된다. 또한 응집제 주입량이 과도하면 오히려 여과저항을 증가시키는 결과를 초래하는 것을 알 수 있었다.

최근 다국적 기업의 성공적인 지식이전(knowledge transfer)에 관한 연구는 꾸준히 진행되어 오고 있다. 그러나 지금까지의 선행연구들은 지식이전 대상에 있어, 합작투자나 전략적제휴의 관계에서 파트너간의 지식이전에 초점을 두고 있으며, 지식특성의 관점에서 볼 때, 대부분 지식의 대상을 기술 및 신제품개발이나 경영노하우에 비중을 두고 있다. 따라서 본 연구에서는 이러한 점을 극복하고자 이전되는 지식을 마케팅지식으로 제한하고 중국에 진출한 한국 다국적기업을 대상으로 모회사와 자회사간의 마케팅지식 이전성과에 영향을 미치는 결정요인에 관해 탐색적·실증적으로 살펴보았다. 특히 본 연구에서는 마케팅지식 이전의 성과에 영향을 미칠 것으로 기대되는 모든 요인들 즉, 지식모호성 특성, 본사 특성, 자회사 특성 그리고 본사와 자회사간의 상호관계적 특성을 모두 고려한 통합적인 모델을 구성하여 마케팅지식 이전에 영향을 미치는 결정요인들을 살펴보았다. 그 결과, 마케팅지식의 암묵성과 복잡성정도가 클수록, 자회사의 경영자율성이 보장될수록 마케팅지식 이전성과에 부정적(-)인 영향을 미치는 것으로 나타났다. 반면, 자회사의 흡수능력이 클수록, 본사의 조직학습문화정도가 클수록, 본사와의 조직문화가 유사할수록 그리고 본사와 자회사 간 신뢰의 정도가 높을수록 마케팅지식 이전성과는 향상되는 것으로 밝혀졌다. 또한 본 연구에서 설정한 통제변수인 기업규모(클수록), 진입형태(합작투자 보다는 100%지분을 통한 신규투자일수록), 그리고 존속년수(적을수록) 역시 마케팅지식 이전성과에 긍정적(+)인 영향을 미치는 것으로 나타났다.

In this study, the odor compounds emitted from the field workplaces at the Pohang steel complex were measured using analytical instruments and the olfactory method. In addition, the reduction of odor emissions by pyroligneous liquid was evaluated. The odor samples were obtained from slag pots and dry pits, which refrigerate hot slag, and the target compounds were hydrogen sulfide (H₂S) and ammonia (NH₃). The levels of odor emissions varied with meteorological and operating conditions, but emissions from dry pits were always much higher than those from slag pots. As the concentration of pyroligneous liquid increased, the concentrations of H₂S and the ratios of dilution decreased. Together with this result and the guideline of odor emissions, the increase of pyroligneous liquid (more than 2.5 times) in cooling water was suggested to reduce odor emissions. Actually, the reduced levels of H₂S at the slag pot and the dry pit were observed (70 and 94%, respectively) after the increased amount of pyroligneous liquid. However, in order to determine the optimal amount of pyroligneous liquid for the economical and efficient removal of odor emissions, the system of cooling water has to be improved and more samples are required for a comprehensive analysis.

This paper describes dynamic characteristics of a power transmission tower consisting of lots of power lines and insulators. A numerical 3D modeling for the static, dynamic and buckling analyses of the power transmission tower is presented considering the case when the power lines are cut. Eigenvalue analysis indicates that the transmission tower shows different behavior comparing to usual structures governed by several low modes. The transmission tower is governed by lots of modes. It is verified that the transmission tower is structurally safe against the static wind and buckling loads. But the structural and buckling safety is not guaranteed when all power lines are cut, which comes to collapse the transmission tower. Further study is in need to overcome such case. Wind dynantic analysis shows that fluctuating wind loads increase the response of the tower.

본 연구에서는 지진하중을 받는 탄성구조물을 대상으로 층전단력 분포에 기초한 마찰감쇠기의 설계방법을 제시하였다. 먼저 마찰감쇠기의 슬립하중(slip-load)을 정규화하는 방법 별로 단자유도 시스템의 수치해석을 수행하고 비교하였다. 이를 통해 슬립하중과 가새 강성의 영향을 파악하였으며, 설치용 가새와 원구조물의 최적강성비를 찾았다. 다음으로는 다양한 고유주기와 층수를 갖는 구조물을 대상으로 수치해석을 통해 마찰감쇠기의 설치 층수와 위치의 결정방법 및 슬립하중의 분배 방법을 도출하였다. 이 과정에서 설치 층수가 포함된 성능지수를 사용하여 슬립하중의 총합으로부터 최적의 설치 층수를 도출하는 경험식을 제시하였다. 마지막으로 실제 지진하중을 사용한 수치해석을 통해 기존의 최적설계 방법과 비교하여 제안된 방법의 우수성을 입증하였다.

In this study, we designed color of tunable and high efficient organic materials using the quantum dynamics and the semi-empirical calculation, and applied this results to the fabrication of organic light-emitting diodes. Also we optimized the molecular structure of phosphorescent materials and the energy transfer from a host to a dye which makes organic light-emitting diodes improve. Using quantum dynamics method, the molecular structures of ligand only and the whole metal chelate were optimized, and these energy levels were calculated. From this test results, we could understand the emission mechanism of phosphors with various ligands as well as design the proper ligands reducing the T-T annihilation and the carrier lifetime. We also could design ligands with various colors using this test method.

The p-type semiconductor thermoelectric materials were fabricated by melting, milling and sintering process and their thermoelectric properties were characterized. The compound materials were ball-milled with milling time and the powders were sintered by spark plasma sintering process. The ball milled powders had equiaxial shape and approedmately in size. The figure of meritz of sintered thermoelectric materials decreased with milling time because of lowered electrical resistivity. The thermoelectric properties of materials have been discussed in terms of electrical property with ball mill process.

In this study, a seismic design methodology for a friction damper based on the story shear force of an elastic building structure is proposed. First, using two normalization methods for the slip-load of a friction damper, numerical analyses of various single-degree-of-freedom systems are performed. From those analyses, the effect of the slip-load and brace stiffness was investigated and the optimal stiffness ratio of the brace versus original structure was found. Second, from the numerical analysis for five multi-story building structures with different natural frequency and the number of story, reasonable decision method for the total number of installation floor, location of installation and distribution of slip-loads are drawn. In addition, an empirical equation on the optimal number of installation floor is proposed. Finally, the superiority of the proposed method compared to the existing design method is verified from the numerical analysis.

In this study, the wind response characteristics of a transmission tower are investigated through stochastic analysis considering the dynamics of a transmission line, The assemblage of the transmission line and insulator are modeled as a double pendulum system connected to the SDOF model of the tower. It is observed that the background component of the overturing moment induced by the wind response of the transmission line has considerable portion in the total overtuming moment. Based on this observation, a rotational viscoelastic damper is proposed for the suppression of the transmission line response to reduce wind load on the transmission tower. To verify the effectiveness of the proposed damper, time history analysis is conducted for various wind velocities. From the result of the analysis, the proposed damper is proved to be effective in the reduction of the background component rather than the resonance component of the support reaction of the transmission line.