• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.21 no.3
• /
• pp.265-273
• /
• 2008

The problem controlling lateral drift by the wind and the earthquake is very important in high rise buildings. But, outrigger system, generally used for residential tall buildings in Korea, has weak points with the occupancy of special space, the difficult construction and the long duration of works. On the other hand, the damper reduces story drifts of building structure by absorbing vibration energy induced by the dynamic loads and the application of damper systems is relatively simple. Also, the lateral drift control system such as outrigger system may raise the wind vibration problem of serviceability like human comfort and this problem may need another vibration control devices. Accordingly, we analyze the effect of the drift control using various dampers to substitute for outrigger system as the efficient system in residential tall buildings.

• Journal of the Korea Institute of Building Construction
• /
• v.9 no.6
• /
• pp.79-89
• /
• 2009

More and more domestic skyscrapers have been rapidly constructed to get enough living space for people living in overcrowded cities. The purpose of skyscrapers is to provide citizens with useful facilities and to establish landmarks and also national and regional symbols. Previous studies have been conducted which focused on the structure, materials, plans, maintenance, and relevant information regarding skyscrapers. Skyscrapers, however, are different from other smaller buildings regarding the residential environment as well as in other ways. Recently, several problems have been raised in that the indiscreetness of current skyscrapers cannot guarantee residents a high quality living environment, and they might contain risks unless criteria are put forward to ensure that the design and facilities provide for this aim. It is judged that a set of performance criteria for the residential environment to ensurethe residents' quality of life could solve this problem. This study therefore aims to suggest a method for the improvement of the residential environment of skyscrapers by establishing residential environment evaluation factors. In conclusion, this study calculates the weight of each evaluation factor using AHP (an analytic hierarchy process) and suggests evaluating criteria. It is expected that this study could be used to propose guidelines for residents at the design and planning stage of building a skyscraper.

• Journal of Korean Association for Spatial Structures
• /
• v.11 no.4
• /
• pp.79-88
• /
• 2011

Recently, complex-shaped tall buildings represented by 3T(Twisted, Tapered, Tilted) are planed largely. A diagrid structural system is one of the most widely used structural system for complex-shaped tall buildings because of its structural efficiency and formativeness. Plans for tilted tall buildings are largely presented because of beauty of a sculpture and many of buildings use diagrid structural systems. Lateral displacements of tilted tall buildings are induced by not only lateral loads but also self weight. Therefore, reduction of lateral responses of tilted tall buildings is as important as typical tall buildings. In this study, a smart TMD is introduced to reduce seismic responses of tilted diagrid tall buildings and its control performance is evaluated. MR damper is employed for the smart TMD and ground-hook controller is used as a control algorithm for the smart TMD. 100-story tall building is used as an example structure. Control performances of uncontrolled case, controlled case with TMD and controlled case with smart TMD are compared and investigated. Numerical simulation has shown that smart TMD presented good control performance for displacement response but acceleration response was not controlled well.

• Geophysics and Geophysical Exploration
• /
• v.25 no.3
• /
• pp.109-119
• /
• 2022

The computational efficiency of reverse time migration (RTM) based on numerical modeling is not secured due to the high-frequency band of several hundred Hz or higher for data acquired through a three-dimensional (3D) ultra-high-resolution (UHR) seismic survey. Therefore, this study develops an RTM program to derive high-quality 3D geological structures using UHR seismic data. In the traditional 3D RTM program, an excitation amplitude technique that stores only the maximum amplitude of the source wavefield and a domain-limiting technique that minimizes the modeling area where the source and receivers are located were used to significantly reduce memory usage and calculation time. The program developed through this study successfully derived a 3D migration image with a horizontal grid size of 1 m for the 3D UHR seismic survey data obtained from the Korea Institute of Geoscience and Mineral Resources in 2019, and geological analysis was conducted.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2002.11a
• /
• pp.297-302
• /
• 2002

지속적인 경제성장으로 초고층 복합 첨단정보빌딩이 급속히 증가하고, 국민생활 수준의 질적향상으로 쾌적한 환경 요구에 부응하여 고급에너지인 전력 소비량이 매년 10%이상 높게 증가하고 있어 효율적인 전력관리가 절실히 요구되고 있다. 전력소비량이 많은 산업(제조업)분야와 건축물분야 다소비시설물의 전력원단위를 분석하고 효율적인 전력관리 방안을 제시하여 전력사용합리화를 이룩하고자 한다.

• 주택과사람들
• /
• s.198
• /
• pp.72-75
• /
• 2006

초고층 주상복합 아파트가 대거 건설되고 있는 요즘, 자연 환경을 선호하는 수요자들을 타깃으로 타운하우스가 건설되고 있다. 타운하우스는 자연 친화적인 환경과 생활의 편리성이 한데 어우러지고 개인의 프라이버시를 보호하면서 동시에 방범·방재 등 관리의 효율성을 높이는 고품격 주택 시장의 신주거 트렌드로 자리 잡고 있다. 고급 수요자들을 타깃으로 수도권 지역에 선보이고 있는 타운하우스를 찾아가보았다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.4 s.107
• /
• pp.351-357
• /
• 2006

In this paper, a direct $TM_{01}-TE_{11}$ mode converter of circular waveguide which is used the approximated design method of mode conversion between $TM_{01}$ and $TE_{11}$ modes is designed for radiation with the maximum directivity of high power energy into air (rom high power microwave antenna system. The proposed direct $TM_{01}-TE_{11}$ mode converter is calculated and designed with an approximated method for non-linear function about an extended non-constant serpentine type of circular waveguide. Then, the designed mode converter is optimized by length of 200 mm and efficiency above 95% by FIM simulation and achieved short length and high efficiency of the antenna by results of fabricated and measured characteristics.

• Korean Journal of Optics and Photonics
• /
• v.14 no.4
• /
• pp.351-354
• /
• 2003

We present a 12.5-GHz interleaved bidirectional ultra-dense wavelength-division-multiplexing transmission over a conventional single mode fiber of 80 km achieving spectral efficiency as high as 0.8-bit/s/Hz. The beat-frequency-locking method is used to stabilize the channel frequency within $\pm$200 MHz error. To facilitate the identification of multiple beat frequency signals, we use a radio-frequency spectrum analyzer. The bidirectional transmission penalty is about 0.3 dB compared with the unidirectional transmission over the same fiber.

• Journal of Korean Society of Steel Construction
• /
• v.22 no.1
• /
• pp.75-85
• /
• 2010

A new freeform structure representing "Diagrid, Cantilevered, Tilted." which has been considered not only its distinctive appearance but also the structural advantages becomes one of the trends in tall building design. Especially in the Diagrid system, loads can be distributed through bracing frame so that it can be save the materials since it has more effective in the structure behavior. But the seismic performance index such as response modification factor is not clearly defined yet. Even though the diagrid is supposed to show higher seismic performance, it is underestimated due to the lack of reliable data. In this paper the response modification factor for the diagrid system is experimentally explored.

• Journal of the Society of Naval Architects of Korea
• /
• v.36 no.1
• /
• pp.99-108
• /
• 1999

The solid modelling program was developed for the 3-D representation and analysis of VEry High-rise Steel Artificial Reefs(VEHSAR) using Visual C++ on the Microsoft's Windows 95(or Windows NT) based on MFC(Microsoft Foundation Class). Importing oriented-object program and CAD/CAM technique, this integrated design system which aims at low cost and high efficiency makes it possible to predict problems and to establish counterplans through visualizing the construction of Very High-rise Steel Artificial Reefs in advance. Also it is useful in enhancing productivity. Introduction of OpenGL makes it display high quality 3D graphics more faster.