• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.20 no.6
• /
• pp.761-767
• /
• 2007

In centralized control system, complicated control systems including sensors, power supply and dampers should be required to satisfy the target response of large-scale structures. The practical applications of the centralized control system, however, is very difficult due to high order finite element model of structures, uncertainty of models, and limitations of the excitation system. In this study, the decentralized response-dependent MR damper of which magnetic field is automatically modulated according to the displacement or velocity transferred to the damper without any sensing and computing systems. this decentralized response-dependent MR damper are investigated according to the ranges of relative magnitude between the control force of MR damper and the story shear force of structures by nonlinear time history analysis. Finally, its performance is compared with centralized LQR algorithm which is used in general centralized control theory for a three story building structure.

• Korean Institute of Interior Design Journal
• /
• v.15 no.4 s.57
• /
• pp.12-20
• /
• 2006

The purpose of this study is to analyze the influence of theory of Cusanus on the Leonardo's theory of the centralized plan. In Renaissance, Neo-Platonism was so popular that is wat influenced nearly every architecture, literature, painting, sculpture and so on. Theory of Neo-Platonism was so various that every Neo-Platonist had his own theory. Among them, Cusanus focused his theory on rationality, mathematics rather than the medieval symbolism and studied the relationship between the God and men. In the same age, Leonardo da Vinci studied the planning system influenced on many architects works, including Bramante s. His planning system came not from symbolic appearance but from his scientific and rational researches as the theory of Cusanus. This study is to compare Cusanus Neo-Platonism theory and artistie view shown in Leonardo da Vinci's memorandum and drawing and to ascertain the influential relationship, abstracting the common things, and to substitute the characteristics that are seen in his centralized space sketch, abstracting the key words. The study on Cusanus will take advantage of the issued books and will requote Cusanus's copied ones.

• Journal of the Korean Society for Library and Information Science
• /
• v.40 no.3
• /
• pp.11-34
• /
• 2006

A national library is a library specifically established and administrated by the government of a nation to serve as the repository of knowledge and information for that country. National libraries are generally a county's designated national repository, collecting literature Published in the country, in the language of the country, or about the country they represent. In case of advanced countries, national libraries have more than one branches at many different locations. Its system is called the distributed national library system. But the National Library of Korea maintains a centralized library system located in Seoul. This research which it tries to pay attention in this problem Point extracted a logical ground and suggested the mid-long term basic plan(S-shaved Branch Library Project) for a National Library of Korea to convert and reconstruct from centralized system to centralized-distributed system.

• Journal of Power Electronics
• /
• v.14 no.4
• /
• pp.733-741
• /
• 2014

The integration of photovoltaic (PV) energy sources into DC grid has gained considerable attention because of its enhanced conversion efficiency with reduced number of power conversion stages. During the integration process, a local control unit is normally included with every power conversion stage of the PV source to accomplish the process of maximum power point tracking. A centralized monitoring and supervisory control unit is required for monitoring, power management, and protection of the entire system. Therefore, we propose a field-programmable gate array (FPGA) based centralized control unit that integrates all local controllers with the centralized monitoring unit. The main focus of this study is on the process of integrating many local control units into a single central unit. In this paper, we present design and optimization procedures for the hardware implementation of FPGA architecture. Furthermore, we propose a transient analysis and control design methodology with consideration of the nonlinear characteristics of the PV source. Hardware experiment results verify the efficiency of the central control unit and controller design.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.10
• /
• pp.1451-1457
• /
• 2013

Recently, new concept of energy systems such as microgrid, smart grid, supergrid, and energy network has been introducing. In this paper, the concept of the centralized micro-energy network, which is an energy community of a building group without district heating system, is introduced. In addition, a mathematical model for optimal operation of the micro-energy network as a main function of an energy management system (EMS) for the micro-energy network is proposed. In order to show the validation, the proposed model is tested through the simulation and analyzed.

• Journal of Korean Institute of Industrial Engineers
• /
• v.43 no.3
• /
• pp.203-212
• /
• 2017

Emissions Trading System (ETS) is utilized in many countries, including South Korea, as an efficient policy to abate GHG (Greenhouse Gas) emissions. Grandfathering on the basis of historic emissions is used as the way to allocate permits in South Korea. It, however, has caused an increase in the emission permits and lack of equity. To overcome these drawbacks, we propose an alternative DEA model for centralized allocation of emission abatement to evaluate the amount of emissions abatement by company based on the energy efficiency. In addition, an empirical analysis of 36 assigned companies for ETS in Korean metal industry is conducted to validate the feasibility of the proposed model. The result of the analysis shows that energy-efficient companies achieve reduced target of the emissions abatement and companies with low energy efficiency score are turned out to have contrary outcome, against the result of applying Grandfathering.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.6
• /
• pp.1141-1149
• /
• 1992

This paper presents a robust centralized control scheme for a magnetic bearing system which supports a rigid rotor at both shaft ends in the radial direction. The negative stiffness element and the inductive force associated with bearing magnetic field are considered in the dynamic model of the system. For this model, the controllability and observability are examined, and then a robust control theory is applied to design two types of multi-input multi-output servocontrollers. A general servocompensator is embedded in the first one and a centralized PID controller is suggested as a second one. By simulation study, the performance of two types of servocontrollers are compared in the aspects of disturbance rejection, reference tracking and the robustness limit.

• The Transactions of the Korea Information Processing Society
• /
• v.4 no.2
• /
• pp.377-383
• /
• 1997

This paper presents the design and the implemenration of a Mutiuser Multimedia Confernce System for synchronous groupwork.The infrastructure of this system is a hybrid srchiercture of centralized and replicated archietctures,that is to maintain sharde information cinsistently and to reduce the overhead of network traffic to the central part.The communication control of data for groupwerk managrment is centralized to the virtual node and the communication control of real data such as audio,video,text is replicated.In order ot provide a realtime audio and video processing,this system uses synamic queues and multithreads.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.37 no.5
• /
• pp.367-377
• /
• 2019

As an alternative navigation system for the non-GNSS (Global Navigation Satellite System) environment, a new type of DBRN (DataBase Referenced Navigation) which applies both gravity gradient and terrain, and combines filter-based algorithm with profile matching was suggested. To improve the stability of the performance compared to the previous study, both centralized and decentralized EKF (Extended Kalman Filter) were constructed based on gravity gradient and terrain data, and one of filters was selected in a timely manner. Then, the final position of a moving vehicle was determined by combining a position from the filter with the one from a profile matching. In the simulation test, it was found that the overall performance was improved to the 19.957m by combining centralized and decentralized EKF compared to the centralized EKF that of 20.779m. Especially, the divergence of centralized EKF in two trajectories located in the plain area disappeared. In addition, the average horizontal error decreased to the 16.704m by re-determining the final position using both filter-based and profile matching solutions. Of course, not all trajectories generated improved performance but there is not a large difference in terms of their horizontal errors. Among nine trajectories, eights show smaller than 20m and only one has 21.654m error. Thus, it would be concluded that the endemic problem of performance inconsistency in the single geophysical DB or algorithm-based DBRN was resolved because the combination of geophysical data and algorithms determined the position with a consistent level of error.

• Journal of the Korean Society for information Management
• /
• v.20 no.1
• /
• pp.301-320
• /
• 2003

The rapidly increasing use of the Internet and advancement of the communication network, the explosive growth of digital contents from personal home pages to professional information service the emerging file exchange service and the development of hacking techniques . these are some of the trends contributing to the spread of illegal reproduction and distribution of digital contents, thus threatening the exclusive copyrights of the creative works that should be legally protected Accordingly, there is urgent need for a digital copyright management system designed to provide centralized management while playing the role of bridge between the copyright owners and users for smooth trading of the rights to digital contents, reliable billing, security measures, and monitoring of illegal use. Therefore, in this study, I examined the requirements of laws and systems for the introduction of the centralized management system to support smooth distribution of digital contents, and also researched on the current status of domestic and international centralized management system for copyrights. Furthermore, 1 tried to provide basic materials for the standardization of digital contents copyright management information through the examination of the essential elements of the centralized digital contents management such as the system for unique identification the standardization for data elements, and the digital rights management (DHM) .