• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.3
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• pp.260-268
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• 2013

Based on classical Berotti discrete iron loss calculation model, the iron loss analysis mathematical model of alternator was proposed in this paper. Considering characteristics of high speed and changing frequency of the alternator, Maxwell 3-D model was built to analyze iron loss corresponding to each running speed in alternator. Based on iron loss model of alternator at rated speed, the rotor claw pole size was made an optimization design. The optimization results showed that alternator's output performance had been improved. A new idea was explored in size optimization design of claw pole alternator.

• Journal of the Korea Society of Computer and Information
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• v.4 no.3
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• pp.121-129
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• 1999

The purpose of this study is to examine the effects of Critical Factors in the use of Personal Computer, Office Automation Information Technology. The author presents a therortical model related Office Automation Information Technology by end-users and suggests how this model should be conceptualized. A model was estimated with data from 98 end-users. The results revealed that degree of organizational support. demographic charateristic, and useful to the task was positively related to usage of Office Automation Information Technology.

• Journal of Power Electronics
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• v.16 no.1
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• pp.310-318
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• 2016

This paper presents a new orthogonal signals generator (OSG) with DC Offset rejection for implementing a phase locked loop (PLL) in single-phase grid-connected power systems. An adaptive filter (AF) based on the least mean square (LMS) algorithm is used to constitute the OSG in this study. The DC offset in the measured grid voltage signal can be significantly rejected in the developed OSG technique. This generates two pure orthogonal signals that are free from the DC offset. As a result, the DC offset rejection performance of the presented single-phase phase locked loop (SPLL) can be enhanced. A mathematical model of the developed OSG and the principle of the adaptive filter based SPLL (AF-SPLL) are presented in detail. Finally, simulation and experimental results demonstrate the feasibility of the proposed AF-SPLL.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.846-851
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• 2000

4-state 바코드의 정보는 우편번호, 배달순서코드, 고객 정보 등을 수록되며, 판독율 향상을 위한 오류정정 코드워드를 적용할 수 있다. 이 4-state 바코드는 우편물 자동구분처리의 효율화 및 우편물류의 정보표현, 전달, 처리를 효율적으로 지원되도록 개발하고 있다. 본 논문은 우편물 접수 및 처리과정에서 필요로 하는 4-state 고객 바코드 인쇄규격 검증 및 판독시스템 개발에 관한 것으로 4개의 높이로 구성된 바들의 특성과 바의 두께 및 공간 값이 균일한 간격으로 바가 인쇄되는 특징을 고려하여 Laser Diode 배열방법을 적용하였다. 또한, 우편물을 자동으로 이송시키고, 일정한 영역에 배열한 Laser Diode에 의하여 바의 두께, 공간, 높이 값을 정확하게 판독될 수 있도록 한 것이다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.4
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• pp.2113-2128
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• 2019

Image thresholding techniques introducing spatial information are widely used image segmentation. Some methods are used to calculate the optimal threshold by building a specific histogram with different parameters, such as gray value of pixel, average gray value and gradient-magnitude, etc. However, these methods still have some limitations. In this paper, an entropic thresholding method based on Gabor histogram (a new 2D histogram constructed by using Gabor filter) is applied to image segmentation, which can distinguish foreground/background, edge and noise of image effectively. Comparing with some methods, including 2D-KSW, GLSC-KSW, 2D-D-KSW and GLGM-KSW, the proposed method, tested on 10 realistic images for segmentation, presents a higher effectiveness and robustness.

• International Journal of Computer Science & Network Security
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• v.23 no.8
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• pp.107-112
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• 2023

World is moving towards digitization at a rapid pace, so the enterprises have developed information systems for management of their business. Empowering educational institutes with information systems are become very important and vital. Doing everything manually is very difficult for students, teachers and staff. Information system can enhance their efficiency and save a lot of time; this research proposed system will solve this issue by providing services like class room reservation, e-library facility, online submission etc. in a secured environment. Up till now limited attention has been paid to utilize robots and drones for automation inside educational institutes. Our proposed system incorporates robots and drones to fill this gap in automation being used in institutes. Through this research, the aim is to improve the efficiency of learning and services in educational institutions or universities.

• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1677-1688
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• 2020

In the sodium-cooled fast reactor, the steam generator is a heat exchange device between sodium and water, which may cause leakage, resulting in a sodium-water reaction accident, which in turn affects the safe operation of the entire nuclear reactor. To this end, the electromagnetic vortex flowmeter is used to detect leakage of the steam generator and its signal processing method is studied in this paper. The hydraulic experiment was carried out by using water instead of liquid sodium, and the sensor output signal of the electromagnetic vortex flowmeter under different gas injection volumes was collected. The bubble noise signal is reflected by the base line of the sensor output signal. According to the relationship between the proportion of the bubble noise signal in the sensor output signal and the gas injection volume, a signal processing method based on the energy ratio calculation is proposed to detect whether the water contains bubbles. The gas injection experiment of liquid sodium was conducted to verify the effectiveness of the signal processing method in the detection of bubbles in sodium, and the minimum detectable leak rate of water in the steam generator was detected to be 0.2 g/s.

• Journal of Power Electronics
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• v.17 no.6
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• pp.1535-1544
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• 2017

Advances in FPGA technology have enabled fast real-time simulation of power converters, filters and loads. FPGA based HIL (Hardware-In-the-Loop) simulators have revolutionized control hardware and software development for power electronics. Common time step sizes in the order of 100ns are sufficient for simulating switching frequency current and voltage ripples. In order to keep the time step as small as possible, ideal switching function models are often used to simulate the phase legs. This often produces inferior results when simulating the discontinuous conduction mode (DCM) and disabled operational states. Therefore, the corresponding measurement and protection units cannot be tested properly. This paper describes a new solution for this problem utilizing a discrete-time PI controller. The PI controller simulates the proper DC and low frequency AC components of the phase leg voltage during disabled operation. It also retains the advantage of fast real-time execution of switch-based models when an accurate simulation of high frequency junction capacitor oscillations is not necessary.

• Journal of the Korean Home Economics Association
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• v.43 no.12 s.214
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• pp.29-41
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• 2005

The purpose of this study was to define the residents' current uses and satisfaction of a home automation system. The data were collected from 85 residents living in a selected intelligent apartment, from whom 72 were used for the final analysis. The results were as follows: 1) The educational background was the most significant variable affecting differences among the groups in terms of use of the home automation system. 2) Even though the over 50 years age group showed a tendency toward lower technology acceptance, their utilization rates of the home automation system were higher than those of the under 40 years age group. 3) The respondents with dual income showed higher rates of utilization of the home automation system than the single income group. 4) In spite of positive satisfaction level for the home automation system, many improvements were still requested.

• Journal of the Korea Safety Management & Science
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• v.26 no.1
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• pp.25-30
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• 2024

Considering the difficulties of the manufacturing industry by improving production efficiency in the era of high wages and aging in domestic automation facilities, automation facilities are considered an irreversible trend, but many serious related disasters are occurring due to the problems of increasing automation facilities due to the enlargement of manufacturing processes, line-up, and automation. The purpose of this study is to review the usage conditions and safety measures for industrial robots that are experiencing serious industrial accidents and are expected to continue to increase in facilities among automation facilities at the automation industrial site and propose ways to ensure the fundamental safety of the facilities at all times The suggestions are as follows. The purpose is to prevent safety accidents in advance by applying safety door aids to industrial sites and installing additional safety devices in safety slide door lock systems applied to safety fence doors of new and already installed facilities to detach safety keys and ensure that workers carry them at all times.