• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.11
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• pp.1090-1099
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• 2004

In this paper a novel design of equilateral-triangular microstrip antenna using PIN diode fur switching the resonant frequency is presented and experimentally studied. The proposed antenna has changed the resonant frequency by length of spur-lines on the patch, and PIN diodes are utilized to switch the spur-line on and off. The shape of the spur-line is changed according to the on and off states of PIN diode and the equilateral triangular microstrip antenna has different resonant frequencies in accordance with them. The resonant frequency is 1.22 GHz with off states since the surface currents flow the periphery of T shape spur-lines, while the resonant frequency is 1.82 GHz with on states since the surface currents are little effect with the conventional equilateral triangular microstrip antenna. The radiation pattern of the proposed antenna has a good linear polarization with the cross polarization of -20 dB both with on and off states.

• KIISE Transactions on Computing Practices
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• v.23 no.2
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• pp.110-115
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• 2017

We propose a new indoor positioning algorithm named Cut-off algorithm. This algorithm cuts off candidates of beacons and reference points in advance, before looking for K neighbor reference points which are guessed to be closest to the user's actual location. The algorithm consists of two phases: off-line phase, and on-line phase. In the off-line phase, RSSI and UUID data from beacons are gathered at reference points placed in the indoor environment, and construct a fingerprint map of the data. In the on-line phase, the map is reduced to a smaller one according to the RSSI data of beacons received from the user's device. The nearest K reference points are selected using the reduced map, which are used for estimating user's location. In both phases, relative ranks of the peak signals received from each beacon are used, which smoothen the fluctuations of the signals. The algorithm is shown to be more efficient in terms of accuracy and estimating time.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1832-1835
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• 1997

Off-line programming systems are widely spread in assembly lines of minute electronic products to huge offshore structures. Any OLP system has to be calibrated before the on-line robot tasks are performed because there are inherent differences between the CAD model on OLP and the real robot workspace. This paper uses simple geometric expressions to propose a calibration method applicable to an OLP for SCARA robots. A positioning task on the two-dimensional horizontal surface was used in the error analysis of a SCARA robot and the anaysis shows that the inaccuracy results from the two error sources non-zero offset angles of two rotational joints at the zero return and differences in link lengths. Pen marks on a sheet of plotting paper are used to determine the accurate data on the joint centers and link dimensions. The calculated offset angles and link lengths are fed back to the OLP for the calibration of the CAD model of the robot and task environments.

• Journal of the Korean Graphic Arts Communication Society
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• v.13 no.1
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• pp.93-104
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• 1995

Liquid crystal-polymer composite(LCPC) films promising new materials for both projection displays and vision product. LCPC films consist of a continous liquid crystal phase embedded in a three- dimensional network of polymer matrix. The liquid crystal in these LC phases can be elecrtrically switched giving rise to an opaque scattering off-stats and a transparent, non-scatting on- stats. In this work. a premixture is composed of LC, UV-curable monomer and photonitiator. LCPC films are formed by photopolymerization induced phase separation from this premixture. In conclusion, structure and electro-optical properties of LCPC films strongly depends on the selection of monomer, LC content and curing rate.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.10
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• pp.982-987
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• 2009

On the controller switching time, even though on-line/off-line controller outputs are the same, a problem which deteriorates the performance of bumpless transfer can happen in case that any discrepancy between the two controller inputs is transferred directly to the controller output. In this paper, we analyze the cause of that phenomenon in existing research results and propose a new method which improves that problem. In order to solve this problem, the off-line controller is augmented to an anti-windup structure and an improved bumpless transfer method is derived by using the changed input of the off-line controller instead of the plant input. We exemplify the performance of the proposed method by comparing with the performance of the existing method via numerical examples.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.4
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• pp.289-295
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• 2008

In this paper, we designed the off-line PWM(Pulse width modulation) control IC for flyback type power converter to reduce the standby power consumption. In normal state, this off-line PWM IC generates the output pulse with $40\sim60kHz$ frequency and duty ratio of $20\sim88%$. When SMPS operates in standby mode, this IC generates the output pulse with 33kHz frequency and duty ratio of 1 %. SPICE simulation was performed to verify the standby power consumption of the power converter with designed of-line PWM IC. Power converter with designed off-line PWM IC consumes less than 0.3W when it operates in standby mode condition.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.4
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• pp.553-557
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• 1996

Heat cycle aging of insulating materials in large generator stator winding has been investigated using both on-line and off-line test methods. On this study, principally, off-line test against actual generator in service was carried out to acquire information about polarization index(PI) and dissipation factor, dissipation factor tip-up, maximum partial discharge for the purpose of remnant breakdown voltage and life assessment. It was found from the tests that both dissipation factor and maximum partial discharge decreased with the increase of operating hours and starting numbers. It was found from off-line tests that the remnant breakdown voltage had a strong relationship with both dissipation factor and maximum partial discharge the remnant breakdown voltage as a results of both operating hours and starting number and the nondestructive tests were proposed as parameters which can predict the remnant lifetime of insulating materials in large generator stator windings. (author). 8 refs., 8 figs., 2 tabs.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.677-678
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• 2009

USB메모리의 분실 및 도난을 통하여 개인정보 유출 사건이 증가함에 따라 보안USB 솔루션이 개발되어 사용자들에게 제공되고 있다. 이러한 보안USB 솔루션은 비밀번호를 기반으로 사용자 인증을 제공 하고 있어 비밀번호 분실 시 보안영역에 접근할 수 없는 불편함을 가지고 있다. 이를 해결하기 위해 여러 보안USB 솔루션에서 서버를 이용한 비밀번호 백업/복구 서비스를 제공하지만 이 또한 네트워크에 연결되어 있지 않은 클라이언트에서 비밀번호를 변경 시 변경된 비밀번호가 서버에 동기화 되지 못하는 문제가 발생되고 있다. 따라서 본 논문은 Off-Line 환경에서 변경된 비밀번호를 USB메모리에 안전하게 저장한 뒤 On-Line 환경으로 변경 시 변경된 비밀번호를 서버와 동기화 하는 방법을 제시한다.

• Journal of Digital Contents Society
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• v.4 no.1
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• pp.57-66
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• 2003

This paper presents the content regarding electronic medical examination chart and data treatment for efficient medical examination and prompt treatment by realizing mutual conversation type remote medical examination system among 3 parties(patient, doctor, pharmacist) on internet base. This is an intelligence type remote medical examination system for both on-line and off-line mode to transcend time and space on the web being participated by anybody, which is cheap type to solve problems in existing remote medical examination system such as high price based on hardware, incompatibility, and so on. By interconnecting ASP and SQL on IIS 4.0 web server, database enables system integration for efficient data processing, on-line consultation between patient and doctor, medical examination on off-line, transmission of medical prescription to pharmacist designated by patient and preparation of medicine, semi-eternal storage of medical examination data owing to storage and search of medical examination data, exact medical examination and prescription using this medical examination data by patient and doctor, and so on.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.3
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• pp.105-115
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• 2008

Urbanization results in increased runoff volume and peak flowrate and shortening in time of concentration, which may cause frequent flooding downstream. There are various types of flow retardation methods including detention ponds, retention ponds, and infiltration ponds. In general, hydrologic models to design the detention pond are classified into planning model and design model. This study is comparing and analyzing of planning model to design the detention pond in urban area. Detention ponds data of Disaster Impact Assessment Report on 22 sites were analyzed to investigate proper planning models in this study. From this research, following conclusions are derived, 1) In case of on-line detention pond, Lee model(1991) is the best planning model and similar to real storage volume. 2) In case of off-line detention pond, Abt and Grigg model is much more proper model compared to other models.