• Journal of Advanced Navigation Technology
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• v.18 no.6
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• pp.541-545
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• 2014

Rec. ITU-R M.1842-1 is international recommendation for VHF band communication guideline in maritime mobile service RR Appendix 18 channels. In this paper, we simulate 28.8 kbps VHF ${\pi}$/4-DQPSK digital baseband modem compatible with the recommendation, then it is designed and implemented with FPGA. Cazac sequence is used as a preamble since packet format is not defined untill now in the recommendation. Baseband modem is designed by VHDL language and implemented on NEXYS4 development platform having Atrix7 FPGA chip from Xilinx. For wireless communication test of total prototype system, ADC/DAC board is implemented and EV9730 RF module is utilized. From the experimental results, implemented FPGA modem shows spectral bandwidth of 25 kHz and successful data exchanges between tx and rx communication platform.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.8C
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• pp.806-813
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• 2009

This paper presents a modem chip design for high-speed wireless communications. Among the high-speed communication technologies, we design the UWB (Ultra-Wideband) modem SoC (System-on-Chip) Chip based on a MB-OFDM scheme which uses wide frequency band and gives low frequency interference to other communication services. The baseband system of the modem SoC chip is designed according to the standard document published by WiMedia. The SoC chip consists of FFT/IFFT (Fast Fourier Transform/Inverse Fast Fourier Transform), transmitter, receiver, symbol synchronizer, frequency offset estimator, Viterbi decoder, and other receiving parts. The chip is designed using 90nm CMOS (Complementary Metal-Oxide-Semiconductor) procedure. The chip size is about 5mm x 5mm and was fab-out in July 20th, 2009.

• Archives of design research
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• v.14 no.2
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• pp.225-234
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• 2001

Technically, the connotation of Typography is more than embodiments which are associated with records, keeping and expressions in languages. Therefore, it reflects a variety of social aspects based on cultures. The tendencies of modem Typography that have been confusing originate from the reaction caused by, what's called, cynical Rationalism - as a kind of characteristic. Nowadays, modem Typographic is required that it experience a new turning point with challenge and innovation. In association with the fact, it tends to be more local, compromised, dialectal, multi-cultural and anti-aesthetic. Moreover, there are multilateral tendencies concerned with generations and wealth & poverty. Consequently, the situation of modem Typographic which was regarded as an immovable role is now needed to change. The vernacular trends of Typographic changing with newer aspects is not always optimistic - it may be failure. However, at least, the experiments of it have expanded the range of modem Typographic. Therefore, the ultimate goal will be to obtain, what's called, potential data some of which are unknown to us.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.1
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• pp.110-115
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• 2006

STSAT-2 is the first satellite which will be launched by the first Korean Space Launch Vehicle(KSLV). Ground station Baseband Control system(GBC) is now developed for STSAT-2. GBC has two functions. One is control data path between satellite control computers and ground station antennas(1.5M, 3.7M, 13M) automatically. The other is sending and receiving data between ground station and satellite. GBC is implemented by FPGA(Field-Programmable Gate Array) which includes almost all logic(for MODEM, PROTOCOL and GBC system control). MODEM in GBC has two uplink FSK modulators(1.2[kbps], 9.6[kbps]) and six downlink FSK demodulators(9.6[kbps], 38.4[kbps]). In hardware, STSAT-2 GBC is smaller than STSAT-1 GBC. In function, STSAT-2 GBC has more features than STSAT-1 GBC. This paper is about GBC structure, functions and test results.

• Korean Institute of Interior Design Journal
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• v.16 no.3 s.62
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• pp.38-45
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• 2007

In the architectural space of modem age, expanding to the vertical and horizontal direction for the interaction between space and space is becoming an indispensable factor, and in this expansion, ramps are being positioned as one of the important factors. With an increased use of ramps, they show a variety of changes in types, functions and even concepts. The space where modem ramps are used exhibits a phenomenon that accommodates and expands many functions as well as the confined function of moving people, and is widening the scope of recognition on the functions of ramp. In addition, this phenomenon can be seen as an architectural reflection on the complexation trend of the modem society, the components comprising a ramp contact the body of experiencers closely and thus have a direct effect on their behavior or feeling, and owing to this, it is a space where new functions and meaning are highly likely to be derived. In this study, spaces where ramps are used stay away from an element of uniform vertical movement but have an independent environment within the entire space, thereby being used as a space dominating the nature of the building, not a subsidiary element of it. In this study, therefore, it could be known that spaces in which ramps are used are different in their meaning according to the patterns, not as an element of uniform vertical movement. In addition, these conclusions are the results by analyzing the patterns of ramps taking place in modem spaces and are thought to be helpful in understanding spaces where ramps are used.

• The Journal of Information Technology
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• v.7 no.3
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• pp.37-45
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• 2004

The representative communication method which is applied in the low-speed power line communication modem with 60bps is single carrier method. It has been used mainly for the control. The single carrier method is very sensitive to a power line communication channel environment. Specially, the severe attenuation of the transmission signal according to the notch characteristics of channel becomes the main cause of communication error. Domestic power line channel environment has this notable feature. In this paper, we implemented the low-speed power line communication system which used the chirp signal method to be strong in notch and noise characteristics. In this research, we proposed the method which transmits 1- '1 Unit symbol Chirp signal' with a 100${\mu}s$ time within 1ms for 1 bit. Also it applied for the Convolution code for an error correction and the Manchester code for a collision perception and an error detection. It used the method which uses the bit correlator for signal detection in the receiver parts. We confirmed that the communication method of the chirp method has a excellent performance compared to single carrier methods with a result of experiment of the low-speed power line communication system with the 60bps.

• Journal of the Korea Fashion and Costume Design Association
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• v.9 no.3
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• pp.167-180
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• 2007

This study analyzes the Asian, African and Latin American cultural hybrids in modem fashion, and offers a direction for desirable cultural hybrids in modem fashion. First, the cultural hybrids have been considered in two aspect: global hybrids and structural hybrids. Second, the trends of Asian, African and Latin American cultural hybrids have been interpreted differently depending on the cultural backgrounds of each area. However, the cultural hybrid representing the change of tradition in Asia, Africa and Latin America is a common trend, and is used to describe the social changes. Third, this study examines the global hybrid trend in modem fashion based on the hybrid trend of Asian, African and Latin American culture found in the four major collections from 2000 S/S to 2005 F/W. Until recently, the exotic images have been determined in the viewpoint of Western world, and utilization by the world-renowned designers in the four major collections plays the major role in converting the regional cultural elements into global ones. Fourth, this study also examines the structural hybrids in modem fashion based on the hybrid trend found in Asian, African and Latin American designer collections between 2000 S/S and 2005 F/W. The works which are connected to the world trend, but are also rooted from the cultural and regional traditions demonstrate the globalization of the Asian, African and Latin American fashion. Fashion is a messenger of a culture, and its importance as a symbol of a cultural trend is growing.

• Journal of the Korean Geographical Society
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• v.38 no.2
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• pp.224-236
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• 2003

This study tries to identify the terms which shared the same meaning with a present-day geographical concept region, or jibang(地方) in Korean, Prior to the initiation of modem geography. The analysis of the annals of the pre-modem political regimes and the earliest geography textbooks ends up with the terms oe(外), bang(方), oebang(外方), ji(地面). These terminologies, although having had almost similar meanings that region intends, nonetheless deliver somewhat different connotation depending on the context and times in and during which they were used. Another finding of significance is that region and jibang, both central .words in contemporary geography, began to be used only after the introduction, by way of Japan, of modem geography in the early 20th century. The colonial experience and subsequent political and social turmoil, however, results in careless uses of the terms in geography teaching and research. Efforts need to be continued to address the problems of misuse of these basic terms and, by doing so, to raise geographical pursuits on a right track.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.10C
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• pp.1433-1443
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• 2004

The power line modem proposed in this paper transmits the remote control signal using CSK(Code Shift Keying) and DS/SS method. The CSK technique provides the increased capacity of transmission and robustness towards noise. Besides, the DS/SS technique provides protection against narrow-band Gaussian interference and multi-path interference. The modem supports full-duplex communication using FDD(Frequency Division Duplex) and the modem structure for forward link is same with that for reverse link. To switch each sub-controlled unit smoothly, 4/$\pi$-DQPSK is adopted for noncoherent demodulation. The PN code for spreading spectrum seues to divide each group which consists of sub-controlled units and Walsh code is used for the M-ary CSK technique. Each block is designed and verified with TMS320C5402 DSP. We show the superiority of the proposed method by analyzing numerically the system performance for the factors of the DS/SS and CSK method ullder additive white Gaussian noise and PBI.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.10
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• pp.1858-1865
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• 2007

In this paper, we introduce the design and implementation of satellite IP modem. The designed satellite IP modem shows the performance of 0.2% overhead, BER=10-5 when Eb/No=6dB, frequency offset of 8KHz, data rate up to 1536Kbps, $F_{if}=140MHz$. The designed system is verified through software simulation and then implemented with MPC86x communication processor, TMS320C6416 DSP, and Altera FPGA. Since each hardware unit is implemented in daughter board for modularity, we can reduce the development time and easily improve the performance with using better processor. Linux is used for embedded OS because it shows better performance in IP manipulation multitask processing, and hardware control through device driver. The implemented system is tested and verified with channel simulator. Since the proposed IP modem shows small size and light weight, that can be used anywhere with easy if you need IP environment.