• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.7
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• pp.16-22
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• 2012

With the increase of consumption of new renewable energy, the use of Electric Double Layer Capacitor(EDLC) is being gradually widened as the next generation energy storage device. In order to expand the market of EDLC which is recently receiving a lot of attraction as a new promising area, development of a charge/discharge cycle tester to measure and test performance, is essential. Therefore, this research designed a circuit to measure capacity and internal resistance and a circuit to measure voltage maintenance properties, based on EDLC's basic charging/discharging properties so it is able to measure the state of charge and discharge at high speed. When evaluating performance characteristics, the 5[V]/100[A] prototype-EDLC charge/discharge testing system developed for this research showed ${\pm}0.1$[%] of accuracy of voltage and current measurement. It was also proved that the developed charge/discharge testing system for EDLC can be applied to the actual industry, when testing the entire system using a program produced for data monitoring and acquisition.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.3
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• pp.398-403
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• 2009

The recent trend of logistics demands for improved monitoring system of the inside of containers including current temperature and other environmental conditions. This paper presents an information processing technique with fuzzy logic that recognizes the current situations inside the target container and can be implemented on intelligent container systems. The ZigBee modules are used to collect information such as temperature, humidity, and shock inside the container in ubiquitous environment. The information processing system using fuzzy logic and the InTouch, one of SCADA(Supervisory Control and Data Acquisition) systems, is implemented to monitor the inside of the container and predict the emergency state.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.2
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• pp.62-69
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• 2009

For the fault diagnosis of power transformer, we develop a diagnosis algorithm based on support vector machine. The proposed fault diagnosis system consists of data acquisition, fault/normal diagnosis, and identification of fault. In data acquisition part, concentrated gases are extracted from transformer for data gas analysis. In fault/normal diagnosis part, KEPCO based decision rule is performed to separate normal state from fault types. The determination of fault type is executed by multi-class SVM in identification part. As the simulation results to verify the effectiveness, the proposed method showed more improved classification results than conventional methods.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.6
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• pp.497-503
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• 2011

Currently in Korea, the simple catenary type overhead contact line system is being applied to both conventional lines and high speed lines of electric railway, and circulation current flowing into the catenary system frequently bring undesirable consequences. Namely, the connector wire has many problems according to a flow of excessive circulation current and arc current on catenary when an electric train runs at high speed. This paper presents the development and application of a real-time data acquisition system designed to measure the electrical characteristics of an overhead catenary system in electric railways. The developed system is capable of storing data of a 25 kV power source in a live wire state through a telemetry environment. The field test results show that the proposed technique and the developed system can be practically applied to measure characteristics of current of an overhead catenary system.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.5
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• pp.99-109
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• 2022

The main reason for the increase in cross-border mergers and acquisitions in developed and emerging countries is globalization and growing economic interdependence across countries. The state of the economy has a significant impact on whether cross-border mergers and acquisitions are encouraged or discouraged by international strategic capital market changes. This study empirically evaluates the influence of determinants of economic development on the scale effect of Cross Border M&As separately on emerging and developed nations as a research gap. We first separated the small and large scale firms based on companies' worth and used panel regression to analyze the impact of GDP, employment rate, and market capitalization on cross-border merger & acquisition deals over the period of 2008-2018. Results indicate that GDP and market capitalization have a positive effect on CBM&A, whereas employment rate has a negative effect on CBM&A deals in large-scale firms of both emerging and developed countries. This study results offer the implication for the potential investors and policymakers to strategically analyze the implementation of cross-border mergers & acquisitions.

• Journal of Korea Multimedia Society
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• v.10 no.6
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• pp.726-736
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• 2007

In this paper, real-time image scanning system using linescan cameras is designed. The system is specially designed to diagnose and analyse the conditions of tunnels such as crack widths through the captured images. The system consists of two major parts, the image acquisition system and the image merging system. To save scanned image data into storage media in real-time, the image acquisition system has been designed with two different control and management modules. The control modules are in charge of controlling the hardware device and the management modules handle system resources so that the scanned images are safely saved to the magnetic storage devices. The system can be mounted to various kinds of vehicles. After taking images, the image merging system generates extended images by combining saved images. Several tests are conducted in laboratory as well as in the field. In the laboratory simulation, both systems are tested several times and upgraded. In the field-testing, the image acquisition system is mounted to a specially designed vehicle and images of the interior surface of the tunnel are captured. The system is successfully tested in a real tunnel with a vehicle at the speed of 20 km/h. The captured images of the tunnel condition including cracks are vivid enough for an expert to diagnose the state of the tunnel using images instead of seeing through his/her eyes.

• Korean Journal of Cognitive Science
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• v.16 no.4
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• pp.351-368
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• 2005

The manual construction of the knowledge-base takes much time and effort, and it is hard to adjust intelligence systems to dynamic and flexible environment. Thus mental development in those systems has been investigated in recent years. Autonomous mental development is a new paradigm for developing autonomous machines, which are adaptive and flexible to the environment. Learning conversation, a kind of mental development, is an important aspect of conversational agents. In this paper, we propose a learning conversation method for conversational agents which uses several promising techniques; speech-act templates and genetic programming. Knowledge acquisition of conversational agents is implemented by finite state machines and templates, and dynamic sentence generation is implemented by genetic programming Several illustrations and usability tests how the usefulness of the proposed method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.5A
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• pp.267-275
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• 2003

In UMTS terminal modem uses 3 step search procedure for initial cell search, which comprises 1) slot synchronization, 2) code group identification and frame synchronization, and 3) scrambling-code identification. The performance of initial cell search procedure depends on search parameters like observation time and threshold. The purpose of this paper is to get the optimal observation time and threshold of each step for minimum mean acquisition time. In this paper we induce mean detection time of each step and mean acquisition timefrom the model of 3 step search procedure using state diagram. Also we propose initial cell search algorithm which utilize window search method against initial oscillator error, and select an appropriate observation time and threshold of each step by the analysis of simulation and induced result. It is shown that the mean acquisition time in multipath fading channel can be shorter than 500ms by using the determined observation time and threshold of each step.

• Journal of electromagnetic engineering and science
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• v.14 no.4
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• pp.329-331
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• 2014

A simple realization of an alignment-free wireless power transmission (WPT) system is presented in this letter. The WPT system consists of a transmitter with three reconfigurable modes corresponding to various controllable magnetic field directions in the azimuthal plane and an algorithm for the optimum mode selection carried by sensing the reflected voltage of the system. Twelve light emitting diodes (LEDs) are used to confirm the on- and off-state of LEDs powered wirelessly by the transmitter at every $15^{\circ}$ of the azimuthal plane. A criterion voltage from the reflected power of the system is found by using the correlation between the reflected voltage and the on- and off-state of the LEDs. Simply by continuous; monitoring of the voltage from the system, the system maintains power to the LEDs. The system is realized by MATLAB/Simulink and a National Instrument data acquisition device (DAQ) board. Measurements using the system show on-state LEDs in the azimuthal plane except at the angles of $60^{\circ}$, $75^{\circ}$, $180^{\circ}$, and $300^{\circ}$.

• International Journal of Knowledge Content Development & Technology
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• v.10 no.3
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• pp.7-20
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• 2020

This study examined the awareness and use of cloud computing services by librarians in selected universities in Edo State. A descriptive survey research design was employed and the instrument used was questionnaire. The population of the study was 132 professional and Para-professional librarians. The total enumeration technique was used to select the entire population because the size was manageable. Simple percentage, frequency count, and mean were used to analyze the data collected. From the analysis of data gathered, it was found that the librarians are aware of the use of OCLC, world cat, and Google docs to a very high extent. It was found that the librarians used cloud computing services and technologies for collection development functions and cataloging. Based on the findings it was recommended that management of the libraries should support librarians by providing adequate funding to the library in order to support the acquisition and maintenance of infrastructure for cloud computing.