• Title/Summary/Keyword: flexible structure

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An Analysis of Managerial and Organizational Status of Korean Construction Firms (국내 건설기업의 경영 및 조직현황 분석)

  • Lee, Dong-Hoon;Kim, Sun-Kuk;Kim, Man-Ki;Shin, Dong-Hwa
    • Korean Journal of Construction Engineering and Management
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    • v.11 no.1
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    • pp.38-47
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    • 2010
  • Builders in Korea are facing significant challenges in the midst of deteriorating market conditions resulting from recent financial crunch and slumping housing sales, etc. To address such changes in management landscape, enterprise organizations need to build an efficient corporate management organization than can ensure prompt and flexible response to changes in surroundings. However, most of them base their management organization on business type and volume due to insufficient understanding and analysis of organization. Top 30 construction companies in Korea have their own management organizations and business structures let alone different competitive edges and challenges. Therefore, this paper attempts to examine the current status of management and organization of construction companies to understand their operational achievements and organizational features in and effort to develop an efficient management strategy and provide inputs contributory to establishment of corporate management organization.

Real-time Semi-active Vibration Control in Cable-stayed Bridges by Shear-type MR damper and Clipped-optimal Control Algorithm (전단형 MR 댐퍼 및 Clipped-optimal 제어알고리즘을 이용한 사장교의 실시간 준능동 진동제어)

  • Heo, Gwanghee;Jeon, Joonryong;Jeon, Seunggon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.20 no.2
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    • pp.113-123
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    • 2016
  • This paper is concerned with an experimental research to control of random vibration caused by external loads specially in cable-stayed bridges which tend to be structurally flexible. For the vibration control, we produced a model structure modelled on Seohae Grand Bridge, and we designed a shear type MR damper. On the center of its middle span, we placed a shear type MR damper which was to control its vibration and also acquire its structural responses such as displacement and acceleration at the same site. The experiments concerning controlling vibration were performed according to a variety of theories including un-control, passive on/off control, and clipped-optimal control. Its control performance was evaluated in terms of the absolute maximum displacements, RMS displacements, the absolute maximum accelerations, RMS accelerations, and the total power required to control the bridge which differ from each different experiment method. Among all the methods applied in this paper, clipped-optimal control method turned out to be the most effective to reduces of displacements, accelerations, and external power. Finally, It is proven that the clipped-optimal control method was effective and useful in the vibration control employing a semi-active devices such MR damper.

Analytical and experimental research on wind-induced vibration in high-rise buildings with tuned liquid column dampers

  • Liu, Ming-Yi;Chiang, Wei-Ling;Chu, Chia-Ren;Lin, Shih-Sheng
    • Wind and Structures
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    • v.6 no.1
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    • pp.71-90
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    • 2003
  • In recent years, high-strength, light-weight materials have been widely used in the construction of high-rise buildings. Such structures generally have flexible, low-damping characteristics. Consequently, wind-induced oscillation greatly affects the structural safety and the comfort of the building's occupants. In this research, wind tunnel experiments were carried out to study the wind-induced vibration of a building with a tuned liquid column damper (TLCD). Then, a model for predicting the aerodynamic response in the across-wind direction was generated. Finally, a computing procedure was developed for the analytical modeling of the structural oscillation in a building with a TLCD under the wind load. The model agrees substantially with the experimental results. Therefore, it may be used to accurately calculate the structural response. Results from this investigation show that the TLCD is more advantageous for reducing the across-wind vibration than the along-wind oscillation. When the across-wind aerodynamic effects are considered, the TLCD more effectively controls the aerodynamic response. Moreover, it is also more useful in suppressing the acceleration than the displacement in biaxial directions. As s result, TLCDs are effective devices for reducing the wind-induced vibration in buildings. Parametric studies have also been conducted to evaluate the effectiveness of the TLCD in suppressing the structural oscillation. This study may help engineers to more correctly predict the aerodynamic response of high-rise buildings as well as select the most appropriate TLCDs for reducing the structural vibration under the wind load. It may also improve the understanding of wind-structure interactions and wind resistant designs for high-rise buildings.

A Study on layout algorithm for metabolic pathway visualization (대사 경로 시각화를 위한 레이아웃 알고리즘 연구)

  • Song, Eun-Ha;Yong, Seunglim
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.5
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    • pp.95-102
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    • 2013
  • In metabolomics, metabolic pathway is represented by well-displayed graph. Metabolic pathways, especially, have a complex binding structure, which makes the graphical representation hard to visualize. There is a problem that edge crossings exponentially increase as the number of nodes grows. To apply automatic graph layout techniques to the genome-scale metabolic flow of metabolism domains, it is very important to reduce unnecessary edge crossing on a metabolic pathway layout. we proposed a metabolic pathway layout algorithm based on 2-layer layout. Our algorithm searches any meaningful component existing in a pathway, such as circular components, highly connected nodes, and the components are drawn in upper layer. Then the remaining subgraphs except meaningful components are drawn in lower layer by utilizing a new radial layout algorithm. It reduces ultimately reduced the number of edge crossings. This algorithm is the basis of flexible analysis for metabolic pathways.

A Methodological Approaches on the Global Green Growth (글로벌 녹색성장의 연구방법론적 고찰)

  • Choi, Yong-Rok
    • International Commerce and Information Review
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    • v.14 no.2
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    • pp.349-367
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    • 2012
  • Recently, the global paradigm on the economic structure has been changed from the price-oriented borderless competition toward the sustainable quality movement due to the ever-increasing global warming and environmental issues. Since Korea hosted the global 20 summit in 2010, it has promoted the green growth policies and asked for the other countries to participate in. Unfortunately, it is not easy to figure out the green growth or green productivity because the economic performance has a side effect of environmental pollution such as CO2 emission. This paper aims to analyzes the methodological comparison for all the related issues with green productivity and suggests the new paradigm of global Malmquist-Lundberger index (GML) as the most flexible field and performance-oriented criteria to measure the green productivity.

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Analytical Simulation of the Seismic Response of a High-Rise RC Building Model (고층 철근콘크리트 건축구조모델의 지진응답에 대한 해석적 모사)

  • Lee, Han-Seon;Lee, Jeong-Jae;Jung, Dong-Wook
    • Journal of the Earthquake Engineering Society of Korea
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    • v.12 no.5
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    • pp.1-10
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    • 2008
  • A series of shaking table tests were conducted on a 1:12 scale model using scaled Taft N21E earthquake records to investigate the seismic performance of a 17-story high-rise reinforced concrete building structure with a high degree of torsional eccentricity and soft-story irregularities in the bottom two stories. The main characteristics of the behaviors were: (1) a sudden change of the predominant vibration mode from the mode of translation and torsion to the torsional mode after the flexible side underwent a substantial inelastic deformation; (2) an abrupt increase in the torsional stiffness during this change of modes; (3) a warping behavior of the wall in the torsional mode; and (4) a unilateral overturning moment in the transverse direction to the table excitations. In this study, efforts were made to simulate the above characteristics using a nonlinear analysis program, Perform3D. The advantages and limitations are presented with the nonlinear models available in this software, as they are related to the correlation between analysis and test results.

Real-time Vibration Control of Cable Bridges using a Shear-type MR Damper-Focusing on Power Model and Lyapunov Control (전단형 MR 댐퍼를 이용한 케이블 교량의 실시간 진동제어-파워 모델 및 리야프노브 제어 중심으로)

  • Heo, Gwanghee;Lee, Chinok;Jeon, Seunggon;Kim, Chunggil;Jeon, Joonryong
    • Journal of the Earthquake Engineering Society of Korea
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    • v.21 no.5
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    • pp.215-226
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    • 2017
  • In this paper, an experimental study was carried out for vibration control of cable bridges with structurally flexible characteristics. For the experiment on vibration control, a model bridge was constructed by reducing the Seohae Grand Bridge and the shear type MR damper was designed using the wind load response measured at Seohae Grand Bridge. The shear type MR damper was installed in the vertical direction at the middle span of the model bridge, and dynamic modeling was performed using the power model. The tests of the vibration control were carried out by non-control, passive on/off control and Lyapunov control method on model bridge with scaled wind load response. The performance of the vibration control was evaluated by calculating absolute maximum displacement, RMS displacement, absolute maximum acceleration, RMS acceleration, and size of applied power using the response (displacement, acceleration, etc.) from the model bridge. As a result, the power model was effective in simulating the nonlinear behavior of the MR damper, and the Lyapunov control method using the MR damper was able to control the vibration of the structure and reduce the size of the power supply.

A Study on an Estimation of Optimum Rice Farm Size (수작농가(水稻作農家)의 적정영농규모계측(適正營農規模計測)에 관(關)한 연구(硏究) -강원도 철원군 평야지역 농가를 중심으로-)

  • Kim, Jong-Pil;Lim, Jae-Hwan
    • Korean Journal of Agricultural Science
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    • v.32 no.1
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    • pp.81-94
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    • 2005
  • This study is aimed at giving the basic information for individual farm households to make decisions for optimizing their farm sizes and for the government to implement farm size optimization policies through the identification of combinations among rice production factors in plain areas like Cheolwon district and the suggestion of the optimal farm sizes of individual farmers based on the scale of economy calculated. The data of agricultural production costs of 50 rice farmers in the plain area which is located in Dongsong-eup Cholwon district, Kangwon province were used in the analysis. The 'translog' cost function among various methods which is a flexible function type was adopted to calculate the scale of economy in rice production. Seemingly unrelated regression(SUR) method was used in forecasting functions and processing other statistics by SHAZAM which is one of the computer aid program for quantitative econometric analysis. In conclusion, the long-run average cost(LAC) curve showed 'U-shape' which was different from 'L-type' one which was shown in the previous studies by others. The lowest point of the LAC was 9.764ha and the concerned production cost amounted to 633 Won/kg. Based on these results, it have to be suggested that around 10 ha of paddy is the target size for policy assistances to save costs under the present level of farming practices and technology. The above results show that the rice production costs could be saved up to 10ha in Cheolwon plain area which is a typical paddy field. However, land use, land condition, land ownership and manager's ability which may affect scale of economy should be considered. Furthermore, reasonable management will have to be realized by means of labor saving technology and cost saving management skill like enlargement of farm size of rice.

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Bridging the Gap Between Science and Industry: The Fraunhofer Model

  • Klingner, Raoul;Behlau, Lothar
    • STI Policy Review
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    • v.3 no.2
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    • pp.130-151
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    • 2012
  • Fraunhofer was founded in 1949 and grew into Europe's largest application-oriented research organization. Fraunhofer currently employs over 20,000 members in Germany, is internationally networked, and manages an R&D budget of over 1,8 Billion Euros per year. An important step for Fraunhofer to become an integral component of the German innovation system was the introduction of the Fraunhofer Model of financing based on a performance-related system of financial management. The underlying model of the allocation and distribution of public funding to Fraunhofer that is subsequently allotted to specific research groups is one of the success factors of Fraunhofer. Fraunhofer is proud of its decentralized organizational model. Fraunhofer is comprised of 60 Institutes in Germany working in different fields, under one legal framework, and with a strong brand value. Every Fraunhofer Institute is affiliated with a German University and every institute director simultaneously holds a chair at the affiliated university. It is a challenge for the headquarter organization to balance the intended competition of individual Fraunhofer Institutes with complementarity cooperation in science among Fraunhofer-Institutes, especially when coming from different knowledge domains; however, this goal results in a significant advantage. The unique strengths of Fraunhofer offer system solutions in a world with increasingly complex R&D challenges. While growing to become the largest organization on Europe to focus on applied research it is the challenge to remain an agile organization that is flexible in organizational structure. Fraunhofer has reached a well-recognized position in the European innovation landscape. It is often referred to by science and governments as a role model for innovation policy and a key element of the latest successes in the German economy that has recovered quicker from the latest economic crisis than most other western economies. The paper explains Fraunhofer as an organizational paradigm and its underlying management model to elaborate on the challenges of managing a research organization. We wish to show how it is possible to transfer the management model and philosophy of Fraunhofer to innovation systems with different framework conditions and challenges. A universal conclusion may be drawn based on the description of Fraunhofer; however, changes in existing structures and innovation systems cannot be implemented over night.

A Development of Shinhanbok Coat Design Using Lattice Window Pattern of Huijeongdang, Changdeokgung Palace (창덕궁 희정당(熙政堂) 창살문양을 활용한 신한복 코트 디자인 개발)

  • Hong, Soojin;Kim, Eunjeong;Bae, Soojeong
    • Journal of Fashion Business
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    • v.24 no.3
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    • pp.121-137
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    • 2020
  • This thesis makes it an aim to develop designs of Shinhanbok coats interpreting and applying the formative structure of the lattice window pattern in Huijeongdang of the Changdeokgung palace, one of the best architecture in Chosun dynasty. Literature review about the history and characteristics of the window of Huijeongdang of the Changdeokgung palace was performed on the basis of the internet resources and papers, and the examples of the fashion design applying the lattice window patterns were analyzed. Then, three style Shinhanbok coats were designed and presented with making use of 6 kind of lattice window patterns as its motif. The coats were designed in flexible size, attempting to clad any kind of body size and shapes. Design 1 drawn from Wanjasal, Tisal, Design 2 drawn from Ajasal, Yongjasal, Tisal, design 3 drawn from Bitsal, Jungjasal. In conclusion, lattice window patterns of the traditional beauty highlighted in view of modern times might be suggested as the motif for expressing the proportion with balance and rhythm with stability. The division of the space with the line was tried with the technique of the bias cutting, stitching and taping with the design of simplicity signified in the aesthetics of the vacant space in addition to its ornamental effects. Thus, this study would like to contribute to the popularity of the Shinhanbok outlined in modern application and unique taste through the study and applications of the traditional lattice window pattern of Korea.