• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.73-81
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• 2011

In this paper, we studied on the building models of open educational resource service system for download or upload their own educational content to be shared with the others without worrying about copyright infringement. We first analyzed the building models of the international OER(Open Educational Resource) service sites. And then, based on these results, we present the new service models suitable to be built the open educational resource service system in phases. The proposed models have the flexibility to accommodate the needs of users and have the advantage that the copyright-related issues of the existing 'National Educational Information Sharing System' could be solved step by step.

• Spatial Information Research
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• v.23 no.4
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• pp.1-11
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• 2015

Since the Spatial Information Open Platform service started in January 2012, the number of service users and the size of the system has increased significantly. However, we could not know the analysis result about how much the hardware resources of the Open Platform system can handle user services. Thereafter, whenever the number of service users are rapidly increased, we simply have solved the service delays using the hardware extension. So, this study presents the obvious solution to avoid the same problem in the future, by pinpointing the system performance of the Open Platform. In this study, through the performance analysis of hardware using NMON and the load test of web service using nGrinder, we intend to get an accurate performance of the Open Platform system. Then we intend to present the resource reallocation method in order to provide better performance of the system.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.131-135
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• 2006

Many alternatives on the residential open building have been researched for corresponding high flexibility and possibility of remodeling in Korea as well. However, existing researches only dealt with two-dimensional floor plan. All buildings as well as apartment housing must have been examined various spatial aspect, three-dimensional not two-dimensional. It will examine basic method of three-dimensional flexible unit system to add to three-dimensional usage method overcoming these limitations. The purpose of this study is to propose the system of three-dimensional residential open building in Korea after examining possibility of flexibility of residential open building in 1.5 times of existing floor height.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.8
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• pp.136-142
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• 2004

This paper deals with the design and implementation of an open architecture CNC system for Wire-EDM, with a consideration of the difference between Wire-EDM and NC cutting machines. Recent open architecture controller(OAC) related research results could be applied to directly access Wire-EDM systems at the CNC level. However, previous research about OAC is mostly aimed at NC cutting machines such as milling or lathes, and hence these results are inadequate to apply to Wire-EDM. To close the gap between previous general research on OAC and Wire-EDM specific needs, an open architecture NC model for Wire-EDM composed of a synchronization kernel and a NC functional module is proposed. Based on the control information flow and Wire-EDM specific machining process, the conceptual CNC model and the detailed implementation model for Wire-EDM is suggested.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.8
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• pp.1116-1120
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• 2014

With the shift of the energy paradigm from supply side management to demand side management, demand resource management and demand response plays an important role in the energy industry. As a consequency, a lot of researches have been done to provide a suitable demand response system. However, most of the demand response systems are based on the propriety products that cannot be modified. In this paper, we are proposing an automated demand response system using an EnerNOC provided open source code. We implemented the demand response server (VTN) and demand response client (VEN), and validated the OpenADR2.0 compliances using the open source code. We also used an Arduino microcontoller to demonstrate the communication schemes to control various devices.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1760-1764
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• 2003

This study was carried out to establish an analytical method on the open circuit seawater pipeline network for open rack vaporizers(ORVs). The linear theory method was chosen to solve this network system. In particular, the method was modified to calculate the static pressure at each node and to determine the operating condition of each pump with the mean static pressure of pumps and ORVs. The proposed method is the first report demonstrating that can be used as a solver for the complicated open circuit. Also, the method indicated the importance for exactly calculating equivalent length of pipes including valves, bends, fittings, and others to raise the accuracy. Although this technique is good for solving this system, it is still required to improve the convergence rate.

• Journal of Power Electronics
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• v.16 no.1
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• pp.57-65
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• 2016

Reverse matrix converters, which can step up voltages, are suitable for applications with source voltages that are lower than load voltages, such as generator systems. Reverse matrix converter topologies are advantageous because they do not require additional components to conventional matrix converters. In this paper, a detection method and a post-fault modulation strategy to operate a converter as close as possible to its desired normal operation under the open-switch fault condition in the rectifier stage are proposed. An open-switch fault in the rectifier stage of a reverse matrix converter causes current distortions and voltage ripples in the system. Therefore, fault-tolerant control for open-switch faults is required to improve the reliability of a system. The proposed strategy determines the appropriate switching stages from among the remaining healthy switches of the converter. This is done based on reference currents or voltages. The performance of the proposed strategy is experimentally verified.

• Smart Structures and Systems
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• v.23 no.6
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• pp.553-564
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• 2019

Modeling of magnetorheological (MR) dampers for cable vibration control to facilitate the design of even more effective and economical systems is still a challenging task. In this study, a parameter-adaptive three-element model is first established for a full-scale MR damper based on laboratory tests. The parameters of the model are represented by a set of empirical formulae in terms of displacement amplitude, voltage input, and excitation frequency. The model is then incorporated into the governing equation of cable-damper system for investigation of open-loop vibration control of stay cables in a cable-stayed bridge. The concept of optimal voltage/current input achieving the maximum damping for the system is put forward and verified. Multi-mode suboptimal and Single-mode optimal open-loop control method is then developed. Important conclusions are drawn on application issues and unique characteristics of open-loop cable vibration control using MR dampers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.327-329
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• 2019

In this paper, we propose an automatic attendance management system for classrooms using OpenCV and machine learning technology. When a face photograph is input at the entrance of the classroom using a general purpose camera for PC, the attendance is checked by comparing the similarity of the face of the already stored student. In this study, the prototype was implemented using the machine learning library dlib, and about 10% of the students had a recognition rate of about 70%.

• International Journal of Railway
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• v.5 no.4
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• pp.135-138
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• 2012

The article suggests criteria of dividing transport systems into systems of limited and open access. Possibilities of implementing principles of the open access in conjunction with the adaptive control at the railway transport have been analyzed. The author makes a grounded conclusion that the development of transport systems based on the open access and adaptive control can play a positive role in overcoming the global instability of the economy and form prerequisites of its stable grows.