In this study, the retractable-roof spatial structure was chosen as the analytical model and a tuned mass damper (TMD) was installed in the analytical model in order to control the seismic response. The analysis model is mainly consisted of runway trusses (RT) and transverse trusses (TT), and the displacement response was analyzed by installing TMD on those trusses. The mass of the single TMD which is installed in the analytical model was set to 1% of the total structure mass and the total TMD mass ratio was set to be 8% or 6%. In addition, the mass of a single TMD was varied depending on the number of installations. As a result of analyzing the optimal number of installations of TMD, the displacement response was reduced in all cases compared to the case without TMD. Above all, the case with 8 TMDs was the most effective in reducing he displacement response. However, in this case, as the load on the upper structure of the retractable-roof spatial structure increases, the total mass ratio of TMD was maintained and the number of TMDs was increased to reduce the mass ratio of one TMD.

In the present study, vanadium oxide(V2O5) films for electrochromic(EC) application are fabricated using sol-gel spin coating method. In order to optimize the EC performance of the V2O5 films, we adjust the amounts of polyvinylpyrrolidone(PVP) added to the solution at 0, 5, 10, and 15 wt%. Due to the effect of added PVP on the V2O5 films, the obtained films show increases of film thickness and crystallinity. Compared to other samples, optimum weight percent(10 wt%) of PVP led to superior EC performance with transmittance modulation(45.43 %), responding speeds(6.0 s at colored state and 6.2 s at bleached state), and coloration efficiency(29.8 cm2/C). This performance improvement can be mainly attributed to the enhanced electrical conductivity and electrochemical activity due to the increased crystallinity and thickness of the V2O5 films. Therefore, V2O5 films fabricated with optimized amount of PVP can be a promising EC material for high-performance EC devices.

In this study, the seismic response is investigated by using a relatively low-rise building under torsion-prone conditions and three seismic loads with change of the location of the seismic isolation system. LRB (Lead Rubber Bearing) was used for the seismic isolator applied to the analytical model. Fixed model without seismic isolation system was set as a basic model and LB models using seismic isolation system were compared. The maximum story drift ratio and the maximum torsional angle were evaluated by using the position of the seismic layer as a variable. It was confirmed that the isolation device is effective for torsional control of planar irregular structures. Also, it was shown that the applicability of the midstory seismic isolation system. Numerical analyses results presented that an isolator installed in the lower layer provided good control performance for the maximum story drift ratio and the maximum torsional angle simultaneously.

This research focuses on developing the Smart material with Grease adopted as a base oil to overcome a particle deposition caused by the MR fluid consisting of a silicon, which maximizing the characteristics and advantage of the MR fluid. By adopting the SMG fluid to a shear damper, this paper aimed to evaluate the control performance of it according to the variation of intensity of electric current(0 A, 0.5 A, 1.0 A, 1.5 A, 2.0 A, 2.5 A) and frequency(0.5 Hz, 1 Hz, 2 Hz). Subsequently, the usability of the SMG damper was analyzed by comparing the dynamic model of it to that of the other types of dampers(Power(Involution) Model, Bingham Model). As a result, DR, the performance indicator of semi-active damper, shows approximately 5 in a condition of 2 Hz. Also while confirming the excellent performance like the Power and the Bingham model, it raises the possibility to exploit it as the semi-active damper.

In the precedent study, the retractable-roof spatial structure was selected as the analytical model and a tuned mass damper (TMD) was installed to control the dynamic response for the earthquake loads. Also, it is analyzed that the installation location of TMD in the analytical model and the optimal number of installations. A single TMD mass installed in the analytical model was set up 1% of the mass of the whole structure, and the optimum installation location was derived according to the number of change. As a result, it was verified that most effective to install eight TMDs regardless of opening or closing. Thus, in this study, eight TMDs were installed in the retractable-roof spatial structure and the optimum mass ratio was inquired while reducing a single TMD. In addition, the optimum mass distribution ratio was identified by redistributing the TMD masses differently depending on the installation position, using the mass ratio of vibration control being the most effective for seismic load. From the analysis results, as it is possible to confirm the optimum mass distribution ratio according to the optimum mass ratio and installation location of the TMD in the the retractable-roof spatial structure, it can be used as a reference in the TMD design for large space structure.

A connected control method for the adjacent buildings has been studied to reduce dynamic responses. In these studies, seismic loads were generally used as an excitation. Recently, multi-hazards loads including earthquake and strong wind loads are employed to investigate control performance of various control systems. Accordingly, strong wind load as well as earthquake load was adopted to evaluate control performance of adaptive smart coupling control system against multi-hazard. To this end, an artificial seismic load in the region of strong seismicity and an artificial wind load in the region of strong winds were generated for control performance evaluation of the coupling control system. Artificial seismic and wind excitations were made by SIMQKE and Kaimal spectrum based on ASCE 7-10. As example buildings, two 20-story and 12-story adjacent buildings were used. An MR (magnetorheological) damper was used as an adaptive smart control device to connect adjacent two buildings. In oder to present nonlinear dynamic behavior of MR damper, Bouc-Wen model was employed in this study. After parametric studies on MR damper capacity, optimal command voltages for MR damper on each seismic and wind loads were investigated. Based on numerical analyses, it was shown that the adaptive smart coupling control system proposed in this study can provide very good control performance for Multi-hazards.

Recently, the concept of an outrigger damper system with a damper added to the existing outrigger system has been developed and applied for dynamic response control of high-rise buildings. However, the study on the structural characteristics and design method of Outrigger damper system is in the early stages. In this study, a 50 story high - rise building was designed and an outrigger damper system with viscoelastic damper was applied for wind response control. The time history analysis was performed by using the kaimal spectrum to create an artificial wind load for a total of 1,000 seconds at 0.1 second intervals. Analysis of the top horizontal maximum displacement response and acceleration response shows that outrigger damper systems are up to 28.33% and 49.26% more effective than conventional outrigger systems, respectively. Also, it is confirmed that the increase of damping ratio of dampers is effective for dynamic response control. However, since increasing the damping capacity increases the economic burden, it is necessary to select the appropriate stiffness and damping value of the outrigger damper system.

The purpose of this study is to verify the effects of a port throttling and 1/4 diagonal port masking of an intake port of an SI engine. The fuel consumption rate increased with port throttling and masking under all operating conditions. However, the rapid combustion effect was increased in all operating conditions. It is consider that this is more influential on the suction resistance than the combustion efficiency increase through intake control. In addition, the increase in the burning velocity indicates that the flame propagation speed is increased by increasing the swirl moment during combustion.

A base isolation system is widely used to reduce seismic responses of low-rise buildings. This system cannot be effectively applied to high-rise buildings because the initial stiffness of the high-rise building with the base isolation system maintains almost the same as the building without the base isolation system to set the yield shear force of the base isolation system larger than the design wind load. To solve this problem, the mid-story isolation system was proposed and applied to many buildings. The mid-story isolation system has two major objectives; first to reduce peak story drift and second to reduce peak drift of the isolation story. Usually, these two objectives are in conflict. In this study, a hybrid mid-story isolation system for a tall building is proposed. A MR (magnetorheological) damper was used to develop the hybrid mid-story isolation system. An existing building with mid-story isolation system, that is “Shiodome Sumitomo Building” a high rise building having a large atrium in the lower levels, was used for control performance evaluation of the hybrid mid-story isolation system. Fuzzy logic controller and genetic algorithm were used to develop the control algorithm for the hybrid mid-story isolation system. It can be seen from analytical results that the hybrid mid-story isolation system can provide better control performance than the ordinary mid-story isolation system and the design process developed in this study is useful for preliminary design of the hybrid mid-story isolation system for a tall building.

The outrigger damper system is a structural system with excellent lateral resistance when a wind load occurs. However, research on outrigger dampers is still in its infancy. In this study, dynamic response control performance of damper is analyzed according to change of stiffness value and damping value of damper. To do this, a real-scale 3D model of 50 stories has been developed and the artificial wind load has been entered for dynamic analysis. Generally, the larger the damping value, the smaller the stiffness value is, the more effective it is to reduce the maximum displacement and acceleration response. However, the larger the attenuation value as the cost of construction increases, it is necessary to select appropriate stiffness and damping value when applying an outrigger damper.

In order for the probe to perform ocean exploration and survey research, it is necessary to adjust the position of the ship as desired by dynamic positioning system. The dynamic positioning system of T/S NARA is applied to K-POS dynamic positioning system of Kongsberg, which makes maintaining the ship's position, changing position and heading control possible. T/S NARA is not capable of dynamic positioning if one or more propulsive forces are lost with DP Level One. However, it is predicted that dynamic positioning can be achieved even at the time of missing one thrust in a good sea condition. Therefore, we want to analyze the effect of each propulsion on the performance of dynamic position system. When one of the bow thruster and azimuth thrusters lost their propulsion, maintaining the ship's position, changing position and heading control performance were compared and analyzed. If the situation occurred disable from using the bow thruster, they can not maintain ship's position. Azimuth thruster was influential for the ship's position control and bow thruster was influential in heading control. The excellent dynamic positioning performance can be achieved, considering the propulsion power that will have a impact on each situation in the future.

본 연구에서는 마찰력에 따른 TMD의 작동-정지조건과 각 조건에 따른 운동방정식을 정리하고, TMD의 마찰계수가 풍진동 제어성능에 미치는 영향을 수치해석을 통하여 확인하였다. 일반적인 하중과 달리 풍하중은 크기와 방향의 변화가 크기 때문에 TMD 는 마찰력에 의하여 작동-정지상태를 반복하게 되므로, TMD의 마찰계수를 주요 변수로 설정하였다. 또한 외부하중의 크기, 구조물의 진동수, TMD의 질량비도 매개변수로 설정하여 TMD의 제진성능에 대한 영향을 파악하고자 하였다. 자유진동, 조화강제진동, 풍진동에 대한 수치해석의 결과, 외부하중의 크기가 작고, 구조물의 진동수가 낮을수록 마찰계수에 의한 TMD의 제진성능의 손실이 커질 수 있음을 확인하였으며, 초고층 건물에 대한 TMD 설계시 마찰계수의 영향을 반드시 고려하여야 할 것으로 판단된다.

본 연구에서는 물/에탄올 분리 성능이 우수한 모데나이트 제올라이트 분리막을 제조하였다. 모데나이트 분리막은 다공성 알루미나 지지체 표면에 종결정이 분산된 종결정 수용액을 이용하여 침지코팅한 후 1SiO2:0.05Al2O3: 0.76NaOH:40H2O 의 몰비로 제조된 수열용액을 이용하여 170°C에서 24시간 동안 이차성장 시켰다. 이때 종결정 수용액의 농도가 모데나이트 분리막의 미세구조 및 투과증발성능에 미치는 영향에 대하여 분석하였다. 종결정 수용액의 농도를 0.025, 0.05, 0.1, 0.25, 0.5 wt%로 한 후 합성한 경우, b축으로 성장된 바늘 구조의 모데나이트 결정은 농도가 증가할수록 c축으로 성장하는 것을 확인하였다. c축으로 성장 된 분리막의 물/에탄올 분리성능은 > 10000의 선택도와 0.2 kg/m2h의 투과도 를 나타냈다.

The demand for skyscrapers is increasing worldwide. Until now, various lateral resistance structures have been used for lateral displacement control of high-rise buildings. An outrigger damper system has been introduced recently to improve lateral dynamic response control performance further. However, a study of outrigger damper system is yet to be sufficiently investigated. In this study, time history analysis was performed to investigate the control performance of an outrigger damper system of high-rise building under eccentric loading. To do this, an actual scale 3-dimensional tall building model with an outrigger damper system was prepared. The control performance of the outrigger damper system was evaluated by varying stiffness and damping values. On the top floor torsional angle response to the earthquake load, was greatly affected by damping value. And the displacement response was affected greatly by the stiffness value and damping value of damper system. In conclusion, it is necessary to select the proper damping and stiffness values of the outrigger damper system.

Membrane bioreactors (MBRs) employ a process of biological treatment that is based on a membrane that has the advantages of producing high-quality treated water and possessing a compact footprint. However, despite these advantages, the occurrence of “fouling” during the operation of these reactors causes the difficulty of maintenance.Hence, in this study, three physical cleaning methods, namely, backwashing, air scrubbing, and mechanical cleaning ball was performed to identify optimum operating conditions through laboratory scale experiments, and apply them in a pilot plant. Further, the existing MBR process was compared with these methods, and the field applicability of a combination of these physical cleaning methods was investigated.Consequently, MCB, direct control of cake fouling on the membrane surface was found to be the most effective. Moreover, as a result of operating with combination of the physical cleaning process in a pilot plant, the TMP increasing rate was found to be – 0.00007 MPa/day, which was 185% higher than that obtained using the existing MBR process. Therefore, assuming fouling only by cake filtration, about one year of operation without chemical cleaning is considered to be feasible through the optimization of the physical cleaning methods.

적외선을 이용한 무기체계의 발달로 인해 항공기의 생존은 큰 위협에 직면해 있다. 따라서 항공기의 생존성 향상을 위해 서 적외선 스텔스 기술이 매우 중요하다. 본 논문에서는 수치해석을 통해 실제 비행환경에서의 항공기 표면온도 및 주위 배 경에 따른 적외선 신호를 분석하고 이를 바탕으로 적외선 스텔스를 위한 항공기 표면 구조체 방사율의 가이드라인을 제시하 고 그 성능을 검증하고자 한다. 수치해석 결과, 주위 배경에 따라서 항공기 표면 방사율을 최적화한다면 항공기와 배경간의 복사대비강도를 감소시킬 수 있음을 확인하였다.

In recent years, an outrigger damper system has been proposed to reduce dynamic responses of tall buildings. However, a study on outrigger damper system is still in its early stages. In this study, time history analysis was performed to investigate the dynamic response control performance of outrigger damper. To do this, a actual scale 3-dimensional tall building model with outrigger damper system has been developed. El Centro earthquake was applied as an earthquake excitation. The control performance of the outrigger damper system was evaluated by varying stiffness and damping values. Analysis results, on the top floor displacement response to the earthquake load, was greatly effected by damping value. And acceleration response greatly was effected by stiffness value of damper system. Therefore, it is necessary to select that proper stiffness and damping values of the outrigger damper system.

부가적인 제어장치를 사용하여 구조물 감쇠를 증가시키는 것은 건축물의 풍응답을 제어하기 위해 자주 사용되는 방법 중 하나이다. 본 연구의 목적은 TMD와 AMD의 다중모드응답 제어성능을 비교하는 것이다. 실제 AMD가 설치된 39층 건물을 사용하였으며, 이전 연구에서 시스템식별을 통해 얻어진 모드정보에 따라 수정된 수치해석모델을 사용하였다. AMD 제어력은 속도피드백, 뱅뱅 제어, LQR 알고리즘을 사용하여 결정하였다. 1차 모드의 RMS 응답을 유사한 수준으로 맞추는 조건에서 TMD와 AMD의 고차모드제 어성능을 비교하였다. 그 결과 TMD는 단일 모드에 대해서만 응답을 저감시킬 수 있었으나, AMD는 다중모드 제어가 가능함을 확인하였다.