• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.6
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• pp.1323-1330
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• 2010

The amount of acoustic data gathered from the acoustic data gathering system is increased dramatically as the acoustic data gathering system become various and highly effective. It is needed to transmit this acoustic data to analysis environment for precise analysis. In this gathering/analysis system, it is also needed the stable transmitting as well as highly perfect security. But the existing system using the conveying method needs a lot of time. In case of using networks, the low speed networking vulnerable in the stable transmitting and the information security is impossible to materialize. In this paper, I would like to propose a transmitting and management system sending a massive gathering acoustic data in the unsecurity and low speed networking environment. The implemented system is to transmit the acoustic data safely in low speed networking environment and secure the acoustic data from various threats.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.3
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• pp.1-11
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• 1999

It is now common practice to utilize the quadrature RF coils to improve the signal-to-noise ratio (SNR) in the Magnetic Resonance Imaging (MRI) System. In addition, to make such an available SNR improvement, it is mandatory to use a well-designed quadrature coupler, which facilitates a perfect 3-dB coupling and quadrature-phase shift. However, the four ports matching condition has to be well considered during the RF excitation and the signal detection period. This work investigates the effects of such a mismatching condition (especially, due to patient) from the analysis, simulation, and real implementation and firstly proposes dynamic loading technique for a quadrature coupler and transmitting/receiving switch module to minimize a patient mismatching and enhance a system reliability. Also, we designed and implemented the quadrature coupler and transmitting/receiving switch module using microstrip. As a result, the SNR of our MRI system using the microstrip quadrature coupler and transmitting/receiving switch module with dynamic load increases 3 dB compared with the old one using USA quadrature switch. Also, the power capability of quadrature coupler and transmitting/receiving switch module is 5-kw peak power. Considering power loss and reduction of size, we used a RT/duroid 6010 substrate with high permittivity and for simulation we use Compact Software.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.4
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• pp.290-293
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• 2018

This paper proposes a new magnetic resonant wireless power transfer system. Two transmitters are arranged to secure a range wider than the existing one-to-one resonance, thereby enhancing the practicality of the system. Two identical transmission units are arranged to strengthen the magnetic field and to subsequently increase the magnitude and distance of the power transmitted to the reception unit. A constant power can be maintained in a wide range through the phase control of different output powers according to the positions of the transmitting and receiving coils. A constant power can also be obtained by transmitting to the receiver. The experiment results show that the proposed method outperforms the conventional method.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1006-1007
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• 2015

Recent improvement in semiconductor technology make efficient switching possible at higher frequencies, which benefits the application of wireless inductive energy transfer. However, a higher frequency does not alter the magnetic coupling between energy transmitter and receiver. Due to the still weak magnetic coupling between transmitting and receiving sides that are separated by a substantial air gap, energy circulates in the primary transmitting side without being transferred to the secondary receiving side. This paper proposes an analysis on the system efficiency to determine the optimal impedance requirement for coils, rectifier and DC-DC Converter. A novel Boost DC-DC Converter is designed to provide the optimal impedance matching in WPT(Wireless Power Transfer) system for various loads.

• Journal of the Korean Vacuum Society
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• v.21 no.1
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• pp.22-28
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• 2012

Transparent dye-sensitized solar cells have been widely investigated for the application to building integrated photovoltaic system. Thin film Si-based solar cells are emerging as a substitute for the dye-sensitized solar cells because their merits of well-established manufacturing processes. Since the selective transmitting layer transmits visible light and reflects infrared light, the solar cell efficiency increases with the introduction of the selective transmitting layer. In this work, AlTiO thin films were grown as the selective transmitting layer by cost-effective sputter deposition and their transmittances were improved by controlling deposition parameters.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.656-659
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• 2017

In this paper, we propose a digital method for transmitting audio signals using LED visible light communication system. In the proposed method, we compare the method for transmitting audio signal in analog signal and the method for transmitting by digital signal. When amplifying the audio sound and transmitting the analog signal using the LED visible light communication, attenuation corresponding to the transmission distance occurs, and there is a disadvantage that it is noisy. In order to overcome this, we propose a method for transmitting digital audio signals. The proposed method has the advantage of reducing the influence of noise, but it turned out that it is affected much by the LED blinking speed. Various methods to overcome this need to be continuously studied.

• Journal of Veterinary Clinics
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• v.13 no.2
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• pp.171-176
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• 1996

In this study, dldctronic identification system of individual dairy cow was developed for autocatization of stoxkvreeding management. To automize the breeding management, it is necessary to obtain and analyze the individual information distinguished from others perferentially. Electronic identification system can distinguish individual livestock from others with electromagnetic wave signal recognition system. Electoronic identification system consists of transmitter transmitting the oscillated signal and receiver set. The transmitted signal from transmitter clung to individual livestock is received from the receiving antenna and the signal in different according to the established value of the register. By distinct signal recieved from the reciever, wi can distinguish the identity of a livestock from others clearly. This system can manage $2^{12}$ individuals with a reciever theoretically. However in order to reduce the errors by analogous signal, this system uses only triple number and can manage 1365 individuals with a reciever practically. This system can be connevtted to Max 232 and microcomputer for the breeding management efficiently.

• Journal of Korea Society of Industrial Information Systems
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• v.6 no.2
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• pp.47-53
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• 2001

Real-time multimedia transmit services like internet broadcasting, web-based education, chatting, conference, circumference observation etc. by using internet are given a great deal of weight on most recently internet services. In these way, various internet services are presented and there applications are also gradually spreaded because of improvement MPEG and streaming processing techniques. But currently internet service is a development of system which has independent function of above services. And a research and development of system which have a multipurpose internet service are insufficiency. In this paper, we design and develop system(RealCam SUN A/V) for transmitting images and voices based on MPEG4 streaming. As a result of our research, it made possible to transmit images with 15 frame/sec in 160×120 frame size at 56Kbps and 30 frame/sec in 640×480 frame size at 512Kbps. And also we can apply this system as multipurpose function to circumference observation and internet broadcasting etc., by transmitting voices, images and control signal simultaneously.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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• pp.37-44
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• 2003

The aim of this research was performance of Web-based real time DGPS using MS visual basic 6.0 Active X control. This system supported the navigation of rover by transmitting the DGPS correction information of base station via internet and monitored the moving of rover by displaying the corrected results received from rover as well as permitting Web users monitoring for rover. The Web-based DGPS server and the client system using MS visual basic 6.0 Active X control for DGPS displayed on Web-browser with the pre analysis was constructed and the system loading test via Web-browser was performed after debugging this system through the static GPS test and publishing it on Web. Also, the wireless internet DGPS test on Web by changing the distance between a base station and a rover was carried out. As the result of the test, the real time DGPS could be performed by transmitting the correction message which calculated from the server system to the client system continually. The rover could be managed by displaying the location information which received from the client system. Other users also could monitor the rover by connecting with this system via internet in real time.

• Journal of Broadcast Engineering
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• v.15 no.1
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• pp.29-39
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• 2010

This paper presents and analyzes laboratory test results of distributed translator (DTxR) for distributed frequency network (DFN) in the ATSC (Advanced Television Systems Committee) terrestrial digital TV broadcasting system. The DTxR laboratory test is classified to receiving part test and transmitting part test. The receiving part test includes dynamic range, random noise, single echo, and adjacent channel interference. The transmitting part test includes quality of output signal (out-of channel emission, quality of transmitting signal, and phase noise), frequency synchronization among output signals, and TxID (Transmitter Identification) signal's affect to the legacy receiver. By the laboratory test results, the receiving part of DTxR eliminates average -2.5 dB of single echo and has average 17.5 dB at TOV (Threshold of Visibility) under random noise environment. In addition, the transmitting part of DTxR satisfies the specification of US FCC (Federal Communications Commission), and frequency difference among DTxR output signals is less than 0.001 Hz.