준능동 TMD를 이용한 메가골조구조물의 진동제어

김현수,이동근 한국지진공학회 2007 한국지진공학회논문집 Vol.11 No.2

메가골조시스템은 사용되는 구조재료를 절약하면서도 구조물의 강성을 효과적으로 높일 수 있는 장점 때문에 고층건물의 설계에 많이 사용되고 있다. 이러한 메가골조시스템이 주로 적용되고 있는 초고층건물의 구조설계에서는 횡하중에 대한 거주자의 불안감을 최소화시키는 것이 주요한 관심사중의 하나이다. 따라서 본 연구에서는 메가골조구조물의 사용성을 향상시키기 위한 방법으로 일반적인 수동 TMD의 제어성능을 개선한 준능동 TMD(STMD)를 사용하였다. 이를 위하여 TMD에서 일반적으로 사용되고 있는 수동감쇠기 대신 준능동 MR 감쇠기를 사용하여 STMD를 구성하였다. 메가골조구조물의 일반적인 유한요소해석모델은 매우 많은 수의 자유도로 구성되어 있기 때문에 원형모델을 사용하여 STMD의 제어성능을 검토하는 것은 현실적으로 불가능하다. 따라서 메가골조구조물의 동적 거동을 정확하게 표현할 수 있는 최소한의 자유도를 가진 응축모델을 행렬응축기법을 이용하여 제안하였다. 또한 일반적인 행렬응축기법의 효율성을 향상시키기 위하여 메가골조구조물의 특성을 활용한 다단계 행렬응축기법을 제안하였다. 본 연구에서 제안된 응축모델을 사용한 제어의 효율성과 정확성 및 메가골조구조물에 대한 STMD의 제어성능을 예제해석을 통하여 검증하였다. The mega frame system is becoming popular for the design and construction of skyscrapers because this system exhibits structural efficiency by allowing high rigidity of the structure while minimizing the amount of structural materials to be used. Since the mega frame system is usually adopted for super high-rise buildings, the comfort of occupants may be main concerns in the practical application of this system. For the enhancement of the serviceability of mega frame structures, a semi-active tuned mass damper (STMD) is developed in this study. To this end, a Magnetorheological (MR) damper is employed replacing passive damper as a semi-active damper to improve the control effect of a conventional TMD. Since a conventional finite element model of mega frame structures has significant numbers of DOFs, numerical simulation for investigation of control performances of a STMD is impossible by using the full-order model. Therefore, a reduced-order system using minimal DOFs, which can accurately represent the dynamic behavior of a mega frame structure, is proposed in this study through the matrix condensation technique To improve the efficiency of the matrix condensation technique, multi-level matrix condensation technique is proposed using the structural characteristics of mega frame structures. The efficiency and accuracy of the reduced-order control proposed in this study and the control performance of a STMD were verified using example structures.

메가 이벤트 이후 방치된 스포츠 시설의 활성화를 통한 현대 도시 속 대공간의 새로운 가능성에 관한 연구

이민호(Lee, Min-Ho) 대한건축학회 2013 대한건축학회 학술발표대회 논문집 Vol.33 No.1

Mega structures, created by the necessity of the times, are arguably mono-functional form, so their structure cannot accommodate the diversity of needs in the modern era. As a result, they are neglected and regarded as a problem of city. However, in modern cities, major space in the Mono-function mega structure is also necessary to accommodate the diverse needs of the people. And also, creating new major space in dense city is almost impossible. Therefore, we need to seek about new possibilities for this Mono-function mega structures. Of these, sports facilities, planned to host mega-events, have a tendency to be neglected, caused by heterogeneous scale and absence of suitable programs.

서울의 메가리전(mega-region)화, 어떻게 할 것인가?

김찬동 건국대학교 시민정치연구소 2023 시민정치연구 Vol.7 No.-

김포의 서울시 편입논의는 메가시티의 행정체계개편 논의로 전개되고 있는 중이다. 서울시는 김포시를 편입하는 것이 도시의 공간구조란 관점에서 과연 바람직한 것인가? 도시는 역사적으로 점점 그 영향권역을 확대하여 왔고, 메가폴리스, 도시연담화, 메가 리전, 초광역권 등으로 생활권역이 확대되어 있다. 그러나 행정구역과 계층구조는 나라마다 각각 달라서, 생활권역과 행정권역의 불일치를 해결하는 방법도 다양하게 나타난다. 한국의 경우는 이 문제를 합병이나 분리 등 급진적 광역행정 수단을 사용하는 경향이 강한데, 이는 중앙집권적 지방행정체제의 영향이 크다. 수도권역의 주민들의 생활권역은 이미 서울을 넘어, 경기도와 심지어 충청도와 강원도까지 확대되었다. 경기도는 분도를 주장하고 있고, 인천도 특별자치도 구상을 제시하여, 구역논의의 갈등을 어떻게 풀어야 할지 난제가 되고 있다. 서울시는 메가리전 현상에 대응하는 대안으로 한국형 레지옹 구상을 제시해 본다. The discussion on Gimpo's incorporation into Seoul is developing into a discussion on the reorganization of the administrative system of Mega City. Is it really desirable for Seoul to incorporate Gimpo City from the perspective of the spatial structure of the city? Historically, the city has gradually expanded its sphere of influence, and the living area has been expanded to megapolis, urban conurbation, mega-regions, and ultra-wide areas. However, since administrative districts and hierarchical structures are different from country to country, there are various ways to resolve the inconsistency between living and administrative areas. In the case of Korea, there is a strong tendency to use radical metropolitan administrative measures such as merger or separation, which is largely influenced by the centralized local administration system. The living area of the residents of the metropolitan area has already expanded beyond Seoul, Gyeonggi-do, and even Chungcheong-do and Gangwon-do. Gyeonggi-do is insisting on a division and proposing the Incheon Special Self-Governing Province Plan, making it a difficult problem on how to resolve the conflict of regional discussions. The Seoul Metropolitan Government proposes the Korean-style Legion Plan as an alternative to respond to the Mega-region phenomenon.

연계중심 군집화를 통한 거대도시 분석

한이철 ( Yicheol Han ),이정재 ( Jeongjae Lee ),임상봉 ( Sangbong Im ) 한국농공학회 2011 한국농공학회 학술대회초록집 Vol.2011 No.-

The mega-region rose as new economic unit. It is defined by connected networks of metropolitan areas, contiguous “functional urban regions” each with an employment core and a commuting ring, or integrated sets of cities and their surrounding suburban hinterlands across which labor and capital can be reallocated at very low cost. Even though those importance of mega-regions and strong relationship with commuting data, there are not widely used methods for detecting the boundary of them except night-time lights. The mega-region is the spatial structure organized by commuters among regions, and commuting is presented by network form. Therefore large communities of commuting network can be regarded as mega-regions, and we can use community detecting method to analysis the mega-regions. Many methods have been proposed to uncover the community structure of networks. Among them the hierarchical clustering method using dendrogram is used as the principal technique to detecting communities under the assumption that every node belongs to only one community. That method, however, does not allow for overlapping communities of nodes, although overlapping as well as hierarchy is usually regarded to the crucial features of communities in many real networks. Overlapping means that nodes may simultaneously belong to more than one group. Thus community structure cannot project the relationship among overlapped groups. To capture hierarchy and overlapping concepts, link community was proposed. They redefined community as group of links rather than nodes and showed that link community method reconciled the antagonistic two network structure concepts. In this paper we evolve link community method for detecting mega-regions and analyze the characteristics of detected regions. Firstly, we propose a link vector in order to present directed and weighted network. A directed and weighted network is described as n by n matrix. Here a row (or column) of matrix is type of a vector. A link and its connected situations can be also described as vector form which contains the information about connected nodes and their weights. Then we suggest new similarity formula which means the angle between link vectors using dot product. If a link is a vector, degree of parallel between two vectors in n-dimensions implies similarity. Using dot product and trigonometric functions we can get the degree of parallel as angle between them. Finally, we apply the evolved link community model to commuting network data to detect and analyze mega-regions.

부유체식 Container Yard에 관한 연구

박성현(Sung-Hyeon Park),박석주(Sok-Chu Park),고재용(Jae-Yong Ko) 한국항해항만학회 2003 한국항해항만학회지 Vol.27 No.1

우리나라가 세계 물류기지의 중심 국으로 발전하기 위해서는 날로 급증하고 있는 물류량을 처리하기 위한 항만의 건설이 시급한 과제이다. 국토가 좁고 대도시에 인구가 집중하고 있으나 삼면이 바다로 둘러 쌓여 있는 우리나라의 경우에는 해양공간개발이 필요하다. 증가하는 물류량을 처리할 수 있는 항만의 건설을 위하여 본 연구에서는 초대형 부유체식 컨테이너 야드를 제안하고, 해상에 설치되는 초대형 부유체식 컨테이너 야드가 파의 길이, 해역의 수심, 입사하는 파의 방향 등에 따라서 어떠한 응답특성을 나타내는지 파악한다. Recently, mega-float offshore structure is studied as one of the effective utilization of the ocean space. And mega-float structure are now being considered for various applications such as floating airports, container yard, offshore cities and so on. This mega-float structure is relatively flexible compared with floating structures like large ships. When we estimate dynamic responses of these structures in waves, the elastic deformation is important, because vertical dimension is small comparea with horizontal. The analysis of the dynamic response as it receives regular wave is studied. The finite element method is used in the analysis of structural section of this model. And the analysis is carried out using the boundary element method in the fluid division. In order to know the characteristics of the dynamic response of the mega-float structures, effects of wavelength, water depth, and wave direction on dynamic-response of the floating structure are studied by use of numerical calculation.

메가기둥 – 아웃리거 - 전단벽으로 구성된 초고층 건물의 단면 최적설계에 관한 연구

정은영,박성수 대한건축학회지회연합회 2015 대한건축학회연합논문집 Vol.17 No.6

최근 제한된 공간 이용의 효율성을 극대화하기 위하여 초고층 구조 시스템의 설계에서 건물의 높이 경쟁보다는 공간의 형태와 활용성을 극대화 할 수 있는 구조물로서의 기능 갖춘 메가 기둥 시스템을 도입하고 있다. 이 시스템의 중요한 특징으로 메가 기둥 대부분의 하중을 지지하도록 설계되어 구조물의 평면효율 극대화가 가능하게 되는 반면에 거대한 기둥의 설치로 인하여 구조적 과다 설계의 문제가 제기되기도 한다. 본 연구에서는 메가 구조로 시공된 ICC TOWER의 단면과 시스템을 연구모델로 단면 설계 초기 과정에서 최적화 과정을 도입하여 메가 기둥의 물량을 추가적으로 감소시킬 수 있다는 것을 확인하였다. 초고층 건물에서 많이 도입되고 있는 메가 구조시스템의 특성을 반영한 최적화 개념(아웃리거 근사해석법)을 도입하면 보다 경제적이고 효율적인 설계가 가능하다고 판단된다. Recently, the Mega-column system has been introducing for high-rise buildings. This system is designed to maximize the utilization of the limited space rather than the height of building. The mega-column supports most of the loads, so that the structure makes it possible to maximize the space efficiency. On the other hand, the problem is on the over-design of structural design. In this study, in order to solve this problem, we introduced the optimization design process into the initial phase of the cross-section. As a result, it was found that it is possible to reduce the amount of mega columns. As a conclusion, when introducing the optimization techniques using Matlab which is 'Outrigger Approximation Method' based on the characteristics of the mega structures, it is possible to design more economic and efficient building.

메타볼리즘의 개념을 적용한 메가스트럭처 디자인에 관한 연구

최영철(Choi Yeong-Cheol),구영민(Koo Young-Min) 대한건축학회 2007 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.27 No.1

This study intends to reinvestigate the process of architectural evolution on the basis of architectural Metabolism, once explored in 1960’, s to discuss the philosophical speculation of Kisho Kuroka and Arata Isozaki on the basis of structuralism, and to examine how the ’Physics of Foam' devised by Denis Weaire and Robert Phelan is related with the Metabolists' approaches with regard to structuralism. Then, the study explores the so called Weaire-Phelan structure, attempts to analogize the natural water - foam - image to design a mega-structure, and finally review the applicability of the structural, spatial, and environmental technology of the structure.

Aseismic Optimization of Mega-sub Controlled Structures Based on Gaussian Process Surrogate Model

Yanjie Xiao,Feng Yue,Xun'an Zhang,Muhammad Moman Shahzad 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.5

Due to the complex seismic characteristics of mega-sub controlled structures (MSCS), it is difficult to give full play to their advantages in earthquake resistance by traditional design methods. Meta-heuristic optimization algorithms can be used to improve the seismic performance, but the structural response needs to be calculated repeatedly, which results in high computation cost. To overcome these challenges, an efficient aseismic optimization design procedure for engineering application is developed. In this procedure, the model of optimization problem is established based on time history analysis (THA). Gaussian process regression (GPR) surrogate models are employed to predict the values of the objective and constraint functions. The expected improvement (EI) and constrained expected improvement (CEI) criteria are adopted to update the training sample set and obtain the optimal solution. Then, two examples are presented to validate the effectiveness and efficiency of this method in optimization problems of structures under earthquake loads. Finally, it is applied to optimizations of a MSCS and a mega frame structure (MFS), respectively. The response and cost of the optimized structures are reduced, and the MSCS shows better earthquake resistant capacities.

올림픽 개회식 예술프로그램의 서사구조 분석 : 2000~2016년 하계올림픽을 중심으로

김산효(Kim Sanhyo) 한국문화융합학회 2021 문화와 융합 Vol.43 No.2

본고는 올림픽 개회식 예술프로그램의 서사구조를 분석하여 구조적 유형과 특징을 도출하는데 목적을 두었다. 연구대상은 2000년부터 2016년까지 개최된 총 다섯 차례의 하계올림픽 개회식 예술프로그램으로 한정하였고, 먼저 예술프로그램의 전체 구조를 분석한 뒤 서사구조에 대해살펴보았다. 그 결과, 향유자에게 주최국 관련 정보를 다양하게 제공한 재현식 선형구조, 주최국의 정체성을 중심으로 문화원형을 적용하고 활용한 순행적 영웅서사구조, 예술프로그램에 긴장과갈등을 일으키는 대립쌍을 등장시켜 관중과 TV시청자들의 몰입과 공감도를 강화한 이항대립구조라는 이상 세 가지 유형을 제시할 수 있었다. 이들은 국제올림픽위원회와 주최국가 및 도시가 예술프로그램의 서사구조를 통해 ‘인지적 공감(cognitive empathy)’을 유발할 수 있는 요인이며, 특수성이 강한 문화가 전 세계인을 대상으로한 공연예술에 활용될 때 보편성을 확보하는 방식을 보여주는 사례이기도 하다. 또한 이 외에다섯 차례 올림픽 개회식 예술프로그램의 서사구조가 올림픽정신을 전달하는 중심 기제로 활용되고 있다는 점 역시 시사하고 있다. 따라서 이상의 분석을 통해 본 연구는 올림픽 개회식 예술프로그램의 서사구조에 개최국별예술의 특수성과 인류가 공감할 수 있는 문화의 보편성을 병치하는 전략이 구현되고 있음을 확인하는 과정을 마련할 수 있었다. This study analyzed the narrative structure of the Olympic Opening Ceremony’s art program in order to summarize its type and characteristics. The subject of the study is the art program of the opening ceremony of the Summer Olympics, which were held between 2000 and 2016. First, we analyzed the entire structure of the art program and looked at the narrative structure. The results of the study were as follows. First, it is a structure that reproduces and lists the culture of the host country. Second, it is the culture and art of the host country and the story structure of heroes over time. Third, the confrontation between the two groups makes the audience nervous and sympathetic. These are factors with which people can sympathize through art programs. Therefore, the narrative structure of the Olympic opening art program shows the process of changing the specificity of art to the universality of culture.

Proposal of Potted Inductor with Enhanced Thermal Transfer for High Power Boost Converter in HEVs

Bong-Gi You,Jeong-Min Ko,Jun-Hyung Kim,Byoung-Kuk Lee 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

A hybrid electric vehicle (HEV) powertrain has more than one energy source including a high-voltage electric battery .However, for a high voltage electric battery, the average current is relatively low for a given power level. Introduced to increase the voltage of a HEV battery, a compact, high-efficiency boost converter, sometimes called a step-up converter, is a dc-dc converter with an output voltage greater than its input voltage. The inductor occupies more than 30% of the total converter volume making it difficult to get high power density. The inductor should have the characteristics of good thermal stability, low weight, low losses and low EMI. In this paper, Mega Flux<SUP>®</SUP> was selected as the core material among potential core candidates. Different structured inductors with Mega Flux<SUP>®</SUP> were fabricated to compare the performance between the conventional air cooled and proposed potting structure. The proposed inductor has reduced the weight by 75% from 8.8kg to 2.18kg and the power density was increased from 15.6W/cc to 56.4W/cc compared with conventional inductor. To optimize the performance of proposed inductor, the potting materials with various thermal conductivities were investigated. Silicone with alumina was chosen as potting materials due to the high thermo-stable properties. The proposed inductors used potting material with thermal conductivities of 0.7W/m·K, 1.0W/m·K and 1.6W/m·K to analyze the thermal performance. Simulations of the proposed inductor were fulfilled in terms of magnetic flux saturation, leakage flux and temperature rise. The temperature rise and power efficiency were measured with the 40kW boost converter. Experimental results show that the proposed inductor reached the temperature saturation of 107°C in 20 minutes. On the other hand, the temperature of conventional inductor rose by 138°C without saturation. And the effect of thermal conductivity was verified as the highest thermal conductivity of potting materials leads to the lowest temperature saturations.