• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1436-1442
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• 2015

In recently the world trend of security system for shipping transport is much more important and stronger, so following the world trend, there is development to security system of shipping transport for national security logistics system construction. it is still ongoing. For the world trend of security system, there is attempt of portable radiation detection, which is possible to get detection of nuclide in south Korea.

• Journal of the Korean Society for information Management
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• v.9 no.1
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• pp.131-164
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• 1992

In this study. a technical report management system using optical technology is described in detail. This management system is designed for both bibliographic (character) and full-text (image) information. Several optical filing systems already on the Korean market are scrutinized and compared with standard functions in order to build a more efficient management system for technical reports which can be easily integrated into existing KRISS library automation system. For that purpose, up-to-date technologies (i.e., digital image PI-ocessing (DIP), MARC standards, and optical character recognition (OCR), etc.) are applied to this system.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.129-130
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• 2010

For the high power demand and N+1 redundancy, this paper presents the digital load share (LS) controller design and the implementation of paralleled phase-shifted full-bridge converters (PSFBC) used in distributed power systems. By adopting the digital control strategy, separately used ICs for PSFBC and LS control functions in analog systems can be merged into a cost-effective digital controller. To compensate and stabilize both PSFBC and LS loops with the direct digital design approaches, small-signal model of the system is derived in discrete-time domain. The steady-state and dynamic load sharing performances are also investigated. Experimental results from two 1.2 kW paralleled PSFBC modules are shown to verify the proposed work.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.9
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• pp.2142-2153
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• 1995

A digital preview controller using optimal LQ control theory is suggested for tandem cold mills to achieve a remarkable improvement of the thickness accuracy. Optimal preview control system is constructed for each rolling stand of tandem cold mills for which the blocked noninteracting control is carried out, and it is compared with the optimal LQ control system which has only feedback control. And in the cases that all/some of disturbance inputs are previewable, full and partial preview controllers are designed, and their performance effects are compared and discussed. The simulation results show that the performance of tandem cold mills can be improved largely through partial preview control.

• Journal of Advanced Marine Engineering and Technology
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• v.17 no.5
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• pp.99-111
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• 1993

In this paper, the current waveform and dynamic characteristics of the proposed system which is composed of a full bridge inverter and low pass LC filter is investigated through the results of computer simulation and experiment to find out the good performance of variable speed AC motor. By the experiment results, it is confirmed that the load current of pseudo sine waves is to be got by the proposed low pass LC filter and the speed of single phase AC motor driven by a full bridge inverter can be smoothly controlled by use of digital PID controller.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.4
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• pp.538-550
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• 1998

The variable frequency and variable voltage AC source made by a conventional inverter which is composed of power semi-conductors includes much noises in sine wave due to high frequency switching of DC source. In this paper the 3rd low pass LC filter for a variable speed 3 phase induction motor driven by a full bridge inverter is introduced to solve the EMI problem by serious noise current. The utility of a modified 3rd order Butterworth LC filter is confirmed through FFT analysis of sine waves and noiseless ACsource can be obtained by the proposed LC filter. The speed of a 3 phase induction motor driven by a full bridge inverter with a LC filter is satisfactorily controlled by a digital PID controller under the condition of stepwise load and setpoint changes.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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• pp.357-364
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• 2003

National Geography Institute(NGI, National mapping agency) has been producing national basemap in automated process since middle of 1980's toward the systematic and efficient management of national land. In 1995, Korean government initiated a full-scale implementation of the National Geographic Information System(NGIS) Development Plan. Under the NGIS Development Plan, NGI began to produce digital maps in the scales of 1:1,000, 1:5,000, 1:25,000. However, digital maps of 1:250,000 or less scale, which are currently used for national land planning, were not included in NGIS Development Plan. Also, the existing laws and specifications related to digital maps of 1:250,000 or less scale are not clearly defined. Therefore this study proposed a feature classification system, which defines features that should be represented in digital map of 1:250,000 or less scale.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4578-4589
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• 2011

The technologies of image acquisition, display, and storage of the breast have been developed in their specialized fields in recent years. The image acquisition system is a device that absorbs and stores images after examining breast tissue using X-ray. Due to the specificity and sensitivity of imaging, the early detection of breast cancer is feasible. In this paper, the current technologies for digital mammography are reviewed, and we propose a digital mammography and evaluate the performance of the implemented system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.3
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• pp.331-337
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• 2016

In this paper, we analyze performances of in-band full-duplex communication system and self-interference (SI) suppression methods in environment where there exists the SI signal. The SI has to be removed to achieve required error rate performance of the system in order - propagation domain, analog domain and digital domain. In propagation domain, the SI signal is attenuated by separating transmitted and received beams physically. In analog and digital domain, after reconstruction of the SI signal using channel estimates and transmit signal, the SI signal can be cancelled from the desired signal. In this paper, assuming that the SI signal can be sufficiently reduced in propagation domain, we demonstrate that the in-band full-duplex communication system can achieve the target error rate by suppressing the SI signal in order - analog and digital domain, based on channel estimates that can be obtained by the method of Least squares.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.656-662
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• 2016

We have provided a variety of domestic construction technology related full-text services through the Construction Technology Digital Library system since 2001. CODIL is a system that services the database related to construction technology data. On the other hand, there is growing demand for DB every year, but the required budget is shrinking. Therefore, this study investigated the satisfaction to effectively service the construction technique-related full-text with a limited budget. The monetary value of full-text to express satisfaction with the quantified value was estimated using the Tobit model. The Tobit model is used as a contingent valuation method to estimate the value of non-market goods. This model is the limited dependent variable regression model to observations by censoring the limit of the left side or right side so that a biased outlier is not reflected in the willingness to pay. A survey was conducted by sampling 312 respondents. The mean, median, truncating the willingness of payment were calculated for the six types of the full-text services using the Tobit model. The statistically significant variables affecting the willingness to pay for the full-text services were identified. The mean value of per the full-text service was estimated to be 46,530 won. The significance of this study was to use the Tobit model to estimate the value of the construction technology-related full-text services for the first time in Korea.