• Health Policy and Management
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• v.33 no.4
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• pp.377-378
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• 2023

The Yoon Suk Yeol administration is promoting the "Global Leap of the Biohealth Industry" as one of its 120 key national policies. Recently, the administration has been showing its commitment by establishing various strategies and presenting blueprints for policy implementation. However, the results felt on the ground are still not sufficient. The biohealth industry is a difficult field to generate policy effects because the related regulations are intricately intertwined and the diverse administrative tasks are scattered in various government departments, where inter-departmental interests differ. To solve this problem, an innovative governance system should be established. In order for the government's recent approach to establish a government-wide control tower to be effective, it should demonstrate a proactive policy commitment and be given practical power to coordinate the interests between departments.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.1
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• pp.17-27
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• 2017

The treatment of rotor wake has been a critical issue in the field of the rotor aerodynamics. This paper presents a new free wake model for the unsteady analysis for a wind turbine. A blade-wake-tower interaction is major source of unsteady aerodynamic loading and noise on the wind turbine. However, this interaction can not be considered in conventional free wake model. Thus, the free wake model named Finite Vortex Element (FVE hereafter) was devised in order to consider the interaction effects. In this new free wake model, the wake-tower interaction was described by dividing one vortex filament into two vortex filaments, when the vortex filament collided with a tower. Each divided vortex filaments were remodeled to make vortex ring and horseshoe vortex to satisfy Kelvin's circulation theorem and Helmholtz's vortex theorem. This model was then used to predict aerodynamic load and wake geometry for the horizontal axis wind turbine. The results of the FVE model were compared with those of the conventional free wake model and the experimental results of SNU wind tunnel test and NREL wind tunnel test under various inflow velocity and yaw condition. The result of the FVE model showed better correlation with experimental data. It was certain that the tower interaction has a strong effect on the unsteady aerodynamic load of blades. Thus, the tower interaction needs to be taken into account for the unsteady load prediction. As a result, this research shows a potential of the FVE for an efficient and versatile numerical tool for unsteady loading analysis of a wind turbine.

• Wind and Structures
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• v.25 no.1
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• pp.79-100
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• 2017

The use of wind energy resources is developing rapidly in recent decades. There is an increasing number of wind farms in high wind-velocity areas such as the Pacific Rim regions. Wind turbine towers are vulnerable to tropical cyclones and tower failures have been reported in an increasing number in these regions. Existing post-disaster failure case studies were mostly performed through forensic investigations and there are few numerical studies that address the collapse mode simulation of wind turbine towers under strong wind loads. In this paper, the wind-induced failure analysis of a conventional 65 m hub high 1.5-MW wind turbine was carried out by means of nonlinear response time-history analyses in a detailed finite element model of the structure. The wind loading was generated based on the wind field parameters adapted from the cyclone boundary layer flow. The analysis results indicate that this particular tower fails due to the formation of a full-section plastic hinge at locations that are consistent with those reported from field investigations, which suggests the validity of the proposed numerical analysis in the assessment of the performance of wind-farms under cyclonic winds. Furthermore, the numerical simulation allows to distinguish different failure stages before the dynamic collapse occurs in the proposed wind turbine tower, opening the door to future research on the control of these intermediate collapse phases.

• Journal of the KSME
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• v.54 no.8
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• pp.32-36
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• 2014

이 글에서는 대표적인 가스터빈 선진업체인 GE와 SIEMENS의 변천 사례를 통해서 국내 가스터빈 산업이 나아가야 할 방향과 이를 위한 산 학 연 관의 협력체계 구축 및 control tower의 필요성에 대하여 알아본다.

• Journal of Digital Convergence
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• v.10 no.1
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• pp.113-123
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• 2012

This Study analyzes effects of establishment and dis-establishment of Ministry of Information and Communication(MIC) to provide a recommendation to the next government. This study compares its background, accomplishments and failures between a MIC establishment by the Civilian Government and a MIC dis-establishment by the current Government. Results of the analysis indicate MIC dis-establishment had negative effects: plunge of IT national competition due to the absence of IT control tower and organizational inefficiency due to poor communication and duplicate investment among inter-governments. This study is significant in that it recommends "Ministry of IT and Media Smart Convergence" establishment to be totally governing IT control tower and cultural content as a new trend for the next government.

• Wind and Structures
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• v.30 no.6
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• pp.663-678
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• 2020

Robust semi-active vibration control of wind turbines using tuned mass dampers (TMDs) is a promising technique. This study investigates a 1.5 megawatt wind turbine controlled by eight different types of tuned mass damper systems of equal mass: a passive TMD, a semi-active varying-spring TMD, a semi-active varying-damper TMD, a semi-active varying-damper-and-spring TMD, as well as these four damper systems paired with an additional smaller passive TMD near the mid-point of the tower. The mechanism and controllers for each of these TMD systems are explained, such as employing magnetorheological dampers for the varying-damper TMD cases. The turbine is modelled as a lumped-mass 3D finite element model. The uncontrolled and controlled turbines are subjected to loading and operational cases including service wind loads on operational turbines, seismic loading with service wind on operational turbines, and high-intensity storm wind loads on parked turbines. The displacement and acceleration responses of the tower at the first and second mode shape maxima were used as the performance indicators. Ultimately, it was found that while all the semi-active TMD systems outperformed the passive systems, it was the semi-active varying-damper-and-spring system that was found to be the most effective overall - capable of controlling vibrations about as effectively with only half the mass as a passive TMD. It was also shown that by reducing the mass of the TMD and adding a second smaller TMD below, the vibrations near the mid-point could be greatly reduced at the cost of slightly increased vibrations at the tower top.

• Smart Structures and Systems
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• v.13 no.2
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• pp.177-201
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• 2014

With the increased size and flexibility of the tower and blades, structural vibrations are becoming a limiting factor towards the design of even larger and more powerful wind turbines. Research into the use of vibration mitigation devices in the turbine tower has been carried out but the use of dampers in the blades has yet to be investigated in detail. Mitigating vibrations will increase the design life and hence economic viability of the turbine blades and allow for continual operation with decreased downtime. The aim of this paper is to investigate the effectiveness of Semi-Active Tuned Mass Dampers (STMDs) in reducing the edgewise vibrations in the turbine blades. A frequency tracking algorithm based on the Short Time Fourier Transform (STFT) technique is used to tune the damper. A theoretical model has been developed to capture the dynamic behaviour of the blades including the coupling with the tower to accurately model the dynamics of the entire turbine structure. The resulting model consists of time dependent equations of motion and negative damping terms due to the coupling present in the system. The performances of the STMDs based vibration controller have been tested under different loading and operating conditions. Numerical analysis has shown that variation in certain parameters of the system, along with the time varying nature of the system matrices has led to the need for STMDs to allow for real-time tuning to the resonant frequencies of the system.

• Journal of Cadastre & Land InformatiX
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• v.44 no.2
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• pp.193-207
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• 2014

The purpose of this study is the issue of public institutions and the financial metrics improve enforcement, public institutions through an integrated management plan for the research is to increase the efficiency of public finances is the purpose of this study. In this paper, the financial operations of public institutions in the five issues (evaluation index system, financial management control framework, Private/Public Sector management, public finance law/institutions, government budget support management) is presented. Issues and a variety of public agencies on how to improve this, this paper proposes the following. the participation of Congress Control Tower(Public Finance Policy Committee )is installed.

• Land and Housing Review
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• v.11 no.4
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• pp.35-50
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• 2020

The purpose of this study is to examine which factors are important in determining the amount of the apartment supply in Changwon City. Additionally, this study is to examine the changes in the determination of the amount of apartment supply in Changwon by dividing it into before and after 2016 as the city showed a large difference in apartment supply that caused structural changes during this time period. This study shows that the increase in the number of housing construction permits in Changwon before 2016 had a negative impact on the housing market as well as causing a decrease in the supply of apartments in Changwon after 2016. As a result of the shortsighted predictions on the housing market of Changwon from before 2016, it still affects the current housing market as of June 2020. The implication of this study is that through the housing market system of Changwon City, they can take the role as a control tower in Changwon City and propose principles and standards for supply control in order to better predict the demand of the housing market.

• Smart Structures and Systems
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• v.13 no.2
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• pp.281-303
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• 2014

In order to suppress the wind-induced vibrations of the Canton Tower, a pair of active mass driver (AMD) systems has been installed on the top of the main structure. The structural principal directions in which the bending modes of the structure are uncoupled are proposed and verified based on the orthogonal projection approach. For the vibration control design in the principal X direction, the simplified model of the structure is developed based on the finite element model and modified according to the field measurements under wind excitations. The AMD system driven by permanent magnet synchronous linear motors are adopted. The dynamical models of the AMD subsystems are determined according to the open-loop test results by using nonlinear least square fitting method. The continuous variable gain feedback (VGF) control strategy is adopted to make the AMD system adaptive to the variation in the intensity of wind excitations. Finally, the field tests of free vibration control are carried out. The field test results of AMD control show that the damping ratio of the first vibration mode increases up to 11 times of the original value without control.