• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1231-1236
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• 2004

In the present work, the practical thermal design process of 1 DIN car DVD receiver described. In the course of its efficient design, CAE technique was essentially used. CAE technique has reduced research period, man power and material cost but has increased research convenience, organized results and persuasive power. CAE technique helped to study parameters such as vent, fan and heat sink. Using these elements, it tried to meet optimal thermal solution. But safety standard, printed circuit board and framework mechanism should be considered as the constraint. To overcome these constraints, we tried to communicate and compromise with projectors in charge. After all, the price of those efforts has made the most competitive heat sink for heat dissipation in the 1 DIN car DVD receiver market. Moreover, we are trying to save $3 per product by removing fan. This paper is supposed to show an example of the CAE technique and help thermal designers to make electronic packaging goods.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.317-320
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• 2006

Ships and their cargos have been managed safely by positioning report system. However, little attention has been paid to safety of crew's works with danger. The attempt that used PHS inboard was before by the present authors. However, the functions were just voice call and mail exchange. The data acquisition from the terminal by proper control was not possible. Thus the position of the terminal was not available. As for the cell phone of next generation, GPS receiver and wireless LAN are installed by manufacturers. Therefore, we propose a system which uses a cell-phone with GPS receiver on a ship in order to promote the safety of ship's crew. We checked the availability of cell-phone GPS receiver at thirty different points inboard. The positioning was not possible in the areas further than 4m from the window. Then, we proposed the system which follows the positions of the crews and confirms their safety inboard by using the VoIP (Voice over Internet Protocol) function by wireless LAN.

• ETRI Journal
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• 제36권5호
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• pp.799-807
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• 2014

In this paper, we design a rake-based cellular radar receiver (CRR) scheme to detect a moving target located in a multipath environment. The modules of Doppler filter banks, threshold level test, and target detection module are newly introduced into the conventional rake receiver so that it can function as a radar system. The proposed CRR tests the Doppler-shift frequency and signal-to-noise ratio of the received signal against predefined threshold levels to determine detection and then calculates target velocities and ranges. The system performance is evaluated in terms of detection probability and the maximum detection range under a Nakagami-n channel that reflects the multipath environment.

• JSTS:Journal of Semiconductor Technology and Science
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• 제4권3호
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• pp.168-173
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• 2004

A low power CMOS receiver baseband analog circuit based on alternating filter and gain stage is reported. For the given specifications of the baseband analog block, optimum allocation of the gain, IIP3 and NF of the each block was performed to minimize current consumption. The fully integrated receiver BBA chain is fabricated in $0.18\;{\mu}m$ CMOS technology and IIP3 of 30 dBm with a gain of 55 dB and noise figure of 31 dB are obtained at 4.86 mW power consumption.

• 전자통신동향분석
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• 제33권2호
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• pp.39-47
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• 2018

The fundamental problem of communication is that of transmitting a message from a source to a destination over a channel through the use of a transmitter and receiver. To derive a theoretically optimal solution, the transmitter and receiver can be divided into several processing blocks, with each component analyzed and optimized. The idea of machine learning (or deep learning) communications systems goes back to the original definition of the communi-cation problem, and optimizes the transmitter and receiver jointly. Although today's systems have been optimized over the last decades, and it seems difficult to compete with their performance, deep learning based communication is attractive owing to its simplicity and the fact that it can learn to communicate over any type of channel without the need for mathematical modeling or analysis.

• Journal of Positioning, Navigation, and Timing
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• 제5권1호
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• pp.29-36
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• 2016

In this paper, performance on receivers of multilateration (MLAT) system that uses ADS-B signal, which is recently becoming popular, was analyzed to overcome shortcomings of existing aircraft flight control systems or reinforce the capabilities. A link budget was analyzed using a channel model in the airport environment with regard to Local Area Multilateration (LAM) for ground-controlled landing around the airport. In order to detect signals that arrived at the receiver successfully, sensitivity of receiver was analyzed using a signal-to-noise ratio (SNR) worksheet, and a method that improves accuracy of the distance measurement was proposed by adopting a peak estimation using sampling signals. Through simulations, optimum specifications of receivers were analyzed to have high precision positioning of LAM, and accuracy of LAM distance measurements was presented.

• 지구물리
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• 제9권3호
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• pp.241-248
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• 2006

In this study, we applied the teleseismic receiver function technique to determine the crustal thicknesses and ratios for 31 broadband stations of the Korean Peninsula and map out the lateral variation of Moho depth in the Peninsula. The estimated depths to Moho range from 26 to 35 km except for an island station ULL (17 km). The Moho is turned out to be deeper in the south-western part of the Peninsula and western Gyeongsang basin, and shallower in the off-shore region close to East Sea (Sea of Japan). The ratio varies from 1.69 to 1.89 with the average of 1.77, which is close to global average (1.78) in the crust.

• Journal of Positioning, Navigation, and Timing
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• 제13권2호
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• pp.149-158
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• 2024

Global Navigation Satellite System (GNSS) receivers are becoming increasingly sophisticated, equipped with advanced features and precise specifications, thus demanding efficient and high-performance hardware platforms. This paper presents the design and implementation of a Field-Programmable Gate Array (FPGA)-based GNSS receiver development platform for multi-band signal processing. This platform utilizes a FPGA to provide a flexible and re-configurable hardware environment, enabling real-time signal processing, position determination, and handling of large-scale data. Integrated signal processing of L/S bands enhances the performance and functionality of GNSS receivers. Key components such as the RF frontend, signal processing modules, and power management are designed to ensure optimal signal reception and processing, supporting multiple GNSS. The developed hardware platform enables real-time signal processing and position determination, supporting multiple GNSS systems, thereby contributing to the advancement of GNSS development and research.

• ETRI Journal
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• 제36권2호
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• pp.188-196
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• 2014

This paper describes a simple delay diversity technique for terrestrial digital multimedia broadcasting (T-DMB) and digital audio broadcasting in a single-frequency network (SFN). For the diversity technique, a delay diversity scheme is adopted. In the delay diversity scheme, a non-delayed signal is transmitted in the first antenna, and delayed versions of the signal are transmitted in each additional antenna. For an SFN environment with multiple transmitters, delay diversity can be executed by controlling the emission times of the transmitters. This SFN delay diversity scheme does not require any hardware changes in either the transmitter or receiver, and perfect backward compatibility can be acquired. To evaluate the performance improvement, laboratory tests are executed with various types of commercial T-DMB receivers as well as a measurement receiver. The improvement in the bit error rate performance is evaluated using a measurement receiver, and an improvement of the threshold of visibility value is evaluated for commercial receivers. Test results show that the T-DMB system can obtain diversity gain using the described technique.

• Journal of Information Science Theory and Practice
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• 제7권2호
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• pp.6-22
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• 2019

The paper explores how information science knowledge can be used systematically in digital, interdisciplinary research settings and gives a conceptual analysis of the relationship between information science knowledge as donor and other research as receiver in an interdisciplinary project environment. The validity of the approach is demonstrated by the author's work on the project "The Primacy of Tense: A. N. Prior Now and Then." The study proposes a hybrid approach, combining analysis and synthesis. The analytical component identifies information systems, assigns an information system type to them, and accesses the information science knowledge associated with that type. The synthetic part focuses on the connections between information systems according to the receiver discipline's practices. The paper makes explicit the actions of experienced information professionals, thereby making their expertise accessible to others. The analytical and synthetic strategies are explained by linking them to two modes of researchers in the receiver discipline, how they act as researchers and what they know about it. The paper offers information professionals concrete assistance with identification of the appropriate strategy for accessing professional knowledge and taking appropriate actions and development decisions.