• 제목/요약/키워드: modem times

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The Performance Test Effected by SDS Traffic in TETRA Network (TETRA 무선 기간망에서 SDS(Short Data Service)트래픽에 따른 성능 평가)

  • Song, Byeong-Kwon;Hwang, Gyu-Bin;Jeong, Tae-Eui;Kim, Gun-Woong;Kim, Jin-Chul;Kim, Young-Eok
    • Proceedings of the KIEE Conference
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    • 2008.11a
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    • pp.376-378
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    • 2008
  • This paper covers that modem performance test is effected by traffic and analysis of the result in TETRA network. The SDS is a method of the between PEIs transmission. And only SDS message type-4 is used to test. The range of the SDS message data length is from 10 to 140 bytes with an increment of 10 bytes. For each length transmitted 1000 times for each delay of inter-transmissions 0.5 second, 1.0 second and 1.5 second. The modem used in the test is the Unimo MU-1000MD by UNIMO Corp.

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Development and Utilization of Digital Telesounder System (디지털 원격 어군 정보 관측시스템의 개발과 이용)

  • 황두진;김동수;백광흠;노천희;정기철
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2000.10a
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    • pp.602-605
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    • 2000
  • This paper describes the development and utilization of digital telesounder system. The digital telesounder system consists of two parts. The one is sea station part, which consist of power, single board computer, A/D converter, and RF modem. The two is land station part, which consist of RF modem, color display, memory system and printer. We obtained good results at the two times of sea experiments. The digital telesounder system is sufficiently good and clear to color display the information of fish school in setnet.

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Design and Implementation of DSP-based Satellite Modem Unit (DSP 기반 위성 모뎀의 설계 및 구현)

  • Cho, Yong-Hoon;Ahn, Jae-Young;Kim, Won-Ho
    • Journal of the Institute of Electronics Engineers of Korea TE
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    • v.37 no.5
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    • pp.93-102
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    • 2000
  • This paper describes the architecture and characteristics of the satellite modem unit (SMU) developed for the DAMA-SCPC Ground System(DGS), which is a Demand Assignment Multiple Access-Single Channel per Carrier (DAMA-SCPC) satellite network. There are several requirements for the SMU from the system architecture and design concept. To meet these requirements the SMU was designed and implemented by extensively applying digital signal processing (DSP) technique and field programmable gate array (FPGA). The developed SMU met the functional and performance requirements, and has been working well. The measured BER was about 1 $\times$10E-4 in continuous mode(at Eb/No=4.7, FEC=3/4).

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Development of Fast Internet based TelePAGS using Satellite Channel (위성 통신을 이용한 고속 인터넷 기반의 원격 PACS 개발)

  • Choi, I.K.;Kim, S.J.;Lee, J.Y.;Hwang, S.C.;Lee, M.H.
    • Proceedings of the KIEE Conference
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    • 1999.07g
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    • pp.3249-3252
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    • 1999
  • In this paper, we present the Tele-PACS of radiology, which uses the communication network as asymetric satellite data communication system. The asymetric satellite data communication system uses receive-only satellite links for data delivery and PSTN(Public Switched Telephone Network) modem or N-ISDN(Integrate Services Digital Network) for communication. The satellite communication linking shows the very high-speed performance than terrestial linking such as 28.8 kbps modem linking and 56Kbps linking. The satellite linking is 5 - 10 times faster than the 56Kbps linking. We conclude that 1) Satellite networking is currently the cheapest and fastest solution for internet access. 2) Web-based Image-Viewer enables small size hospitals in rural area to connect to central PACS easily and to retrieve the image data reliably. 3) The suggested teleradiology system using satellite networking could be adequate to fast telemedicine and telecare for rural hospitals especially located in geographically isolated areas such as islands.

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A CMOS Intermediate-Frequency Transceiver IC for Wireless Local Loop (무선가입자망용 CMOS 중간주파수처리 집적회로)

  • 김종문;이재헌;송호준
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.8A
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    • pp.1252-1258
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    • 1999
  • This paper describes a COMS IF transceiver IC for 10-MHz bandwidth wireless local loops. It interfaces between the RF section and the digital MODEM section and performs the IF-to-baseband (Rx) and baseband-to-IF (Tx) frequency conversions. The chip incorporates variable gain amplifiers, phase-locked loops, low pass filters, analog-to-digital and digital-to-analog converters. It has been implemented in a 0.6 -${\mu}{\textrm}{m}$ 2-poly 3-metal CMOS process. The phase-locked loops include voltage-controlled oscillators, dividers, phase detectors, and charge pumps on chip. The only external complonents are the filter and the varactor-tuned LC tank circuit. The chip size is 4 mm $\times$ 4 mm and the total supply current is about 57 mA at 3.3 V.

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The Performance Comparison Of FSK, BPSK, DPSK In Underwater Communication Channel (수중통신채널에서 FSK, BPSK, DPSK의 성능비교)

  • 박지현;백승관;노용주;윤종락
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2001.05a
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    • pp.359-362
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    • 2001
  • Analog communication systems using AM, FM modem have been developed. Digital communication systems using digital modems, which is by expansion of digital hardware skill have been recently developed. In order to accomplish a reliable communication it is important to overcome ocean environmental channel characteristics such as transmission loss, ambient noise and multipath effect etc. Specially, the effect of multipath is the most important element that determines the performance of underwater communication system in shallow water. Multipath channel can be divided a vertical and horizontal channel. the former is defined the channel to have large path-delay times between a direct wave and reflected waves. The latter shows relatively small path-delay times between a direct and reflected waves in compared with a vertical channel. In this paper, The performance of FSK, PSK and DPSK modem with respect to the vertical and horizontal multipath communication channels it described and compared.

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A Study on the Transition of the Perspective connected with Visual Modality (시각양식과 관련한 투시도법의 변천에 관한 연구)

  • 곽기표
    • Korean Institute of Interior Design Journal
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    • no.38
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    • pp.48-56
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    • 2003
  • This study is purposed to find the transition of the perspective connected with visual modality. The perspective based on Greek optics and euclidean geometry and rediscovered in Renaissance represents the object according to the particular moment and the point of view, is a principal fact which affect architecture, the form of a city and the spatial organization and symbolizes an ideal of the times. It embodied perception which treats the space rationally on the basis of realism and became visual modality based on the separation of the seeing subject and the world of the object. The point of view became one with the vanishing point which made up the shape and after Renaissance for four hundred years a straight line, a right angle and a circle got to be favorite geometrical choices in architecture. A fixed point of view of the subject is getting to change and break up fundamentally by the new visual technologies of the modem times.

A Comparative Study of the Foreign Trade Strategies of Gaisong Merchants and Modern Companies in Korea. (현대기업과 개성상인의 해외진출전략의 비교분석)

  • Park, Sang-Gyu
    • Korean Business Review
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    • v.17
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    • pp.153-183
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    • 2004
  • The Gaisong Merchants can be regarded to playa pioneering role to activate the Korea's trade with foreign countries. In the early period of Yi-Dynasty, the Gaisong Merchants focused on personal trade, but in the middle period of Yi-Dynasty, they entered to the realm of governmental trade. Furthermore, their business activities widened to various forms of trades, for example, smuggling. Utilizing accumulated capital, Gaisong merchants expanded their trading activities to their neighboring countries such as Japan and China. In recent times, it is necessary for modem Korean companies to diversify risks through the establishment of corporations for production, marketing and R&D abroad or through joint venture, M&A and strategic alliance with foreign companies in order to reduce the risks originated from volatile economic and political situations. In this study, we utilize tools of comparative study to compare Gaisong Merchants' foreign trade strategies with those of modem companies such as AMOREPACIFIC, HANILCEMENT and SHINDORICO. The purpose of the paper is to test the hypothesis that modem Korean companies grew up by following the cases of Gaisong Merchants' business activities. We summarize our main findings as follows. First, both Gaisong Merchants and modem Korean companies have common functional core capability in the field of marketing, manufacturing technology, R&D, and human resources development. Second, both Gaisong Merchants and modem Korean companies have common organizational core capability. Third, both Gaisong Merchants and modem Korean companies have common infrastructures such as planning, finance, accounting and MIS. It constitutes the infrastructure of Korea's foreign trade sector. Fourth, both Gaisong Merchants and modem companies have common organizational culture in the field of management policy and philosophy. Actually, those factors are evaluated to be driving forces of Koera's success in foreign trade. In conclusion, the business activities of Gaisong Merchants who represented the peculiarity of Korean business spirit are partially inherited to current Korean business management. The value system and behavior pattern of modern Korean companies is succeeded from the spirit of Gaisong Merchants and it playa major role to specify the identity of Korean business administration.

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Comparison of the Quality Characteristics and Aroma of M. Longissimus from Korean Native Black Pigs and Modem Genotype Pigs during Vacuum Packaged-Chilling (재래종 및 개량종 돼지 등심의 진공포장 냉장중 품질특성 및 향기비교)

  • Kang, Sun-Moon;Lee, Sung-Ki
    • Food Science and Preservation
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    • v.14 no.3
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    • pp.247-255
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    • 2007
  • This study compared the quality characteristics, including aroma, of M. longissimus from five Korean native black barrows(64 kg, KNP) and five modem genotype barrows($Landrace{\times}Yorkshire{\times}Duroc$, 114 kg, MGP), during vacuum packaged-chilling. The samples were vacuum packaged, stored at $2{\pm}0.3^{\circ}C$ for 12 days, and then subjected to quality measurement. The KNP had higher fat content than did MGP(p<0.05), but KNP contained lower C14:0, C18:3 and C20:5 concentrations than did MGP(p<0.05). The KNP showed lower pH values(p<0.05) and water-holding capacities than did MGP, and were redder in color than MGP during storage. The TBARS increased more quickly in KNP than in MGP samples during storage. In texture, KNP showed firmer muscle tone than did MGP during storage(p<0.05). Various aroma compounds including 3-methyl-l-butanol, 2-ethyl hexanol and m-xylene were detected with SPME-GC/MS after 12 days of storage, and aroma patterns of KNP and MGP, obtained with an electronic nose, differed during storage.

Advances in blue and white Light Emitting Diode using AlInGaN mesa structure and Display Module

  • Park, Book-Sung;Kim, Sung-Woon;Jung, In-Sung;Lee, Seon-Gu;Son, Sung-Il;Lee, Jee-Myun;Kim, Eun-Tae;Kim, Chul-Ju
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.347-348
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    • 2008
  • The main goal of this work is advances in 1.0mm $\times$ 0.5mm light emitting diode using AlInGaN cell structure and display module. In the first place, we proposed $200{\mu}m{\times}200{\mu}m$ cell structure using AlInGaN. Secondly, we describe new type 1.0mm $\times$ 0.5mm blue and white LED fabrication procedure and results of an examination include mobile application.

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