• 제목/요약/키워드: multi-modem

검색결과 121건 처리시간 0.021초

An Integrated Evaporation Intenna used sputtering technology for Wireless Microsystems

  • Park, Book-Sung;Jung, In-Sung;Kwon, Sung-Hun;Lee, Seon-Gu;Lee, Jee-Myun;Son, Sung-Il;Kim, Eun-Tae;Kim, Chul-Ju
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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    • pp.158-158
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    • 2008
  • In general, a wireless communication device has employed a whip antenna or a stubby antenna. Recently, wireless communication device is increasingly employing an embedded antenna, Intenna, for the sake of miniaturization. Further, it may employ both external and embedded antennas. Examples of the embedded antenna include a multi-band monopole antenna, which radiates uniformly in all directions when viewed from above, and a planar inverted F antenna (PIFA), which is a variation of the monopole antenna. However, since the conventional antenna is mounted in a finished state on the mobile communication terminal, there is a limitation of space required for providing the antenna. According to the present study, there is provided an Intenna that is deposited on a front or back case of the mobile communication terminal by a sputtering method. Accordingly, it is possible to overcome a limitation of space required for providing the Intenna and to improve the performance of the Intenna formed on the front or back case of the mobile communication terminal.

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Ambient Intelligence in Distributed Modular Systems

  • Ngo Trung Dung;Lund Henrik Hautop
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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    • pp.421-426
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    • 2004
  • Analyzing adaptive possibilities of agents in multi-agents system, we have discovered new aspects of ambient intelligence in distributed modular systems using intelligent building blocks (I-BLOCKS) [1]. This paper describes early scientific researches related to technical design, applicable experiments and evaluation of adaptive processing and information interaction among I-BLOCKS allowing users to easily develop ambient intelligence applications. The processing technology presented in this paper is embedded inside each DUPLO1 brick by microprocessor as well as selected sensors and actuators in addition. Behaviors of an I-BLOCKS modular structure are defined by the internal processing functionality of each I-Blocks in such structure and communication capacities between I-BLOCKS. Users of the I-BLOCKS system can do 'programming by building' and thereby create specific functionalities of a modular structure of intelligent artefacts without the need to learn and use traditional programming language. From investigating different effects of modem artificial intelligence, I-BLOCKS we have developed might possibly contain potential possibilities for developing applications in ambient intelligence (AmI) environments. To illustrate these possibilities, the paper presents a range of different experimental scenarios in which I-BLOCKS have been used to set-up reconfigurable modular systems. The paper also reports briefly about earlier experiments of I-BLOCKS in different research fields, allowing users to construct AmI applications by a just defined concept of modular artefacts [3].

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Survey of Acoustic Frequency Use for Underwater Acoustic Cognitive Technology

  • Cho, A-ra;Choi, Youngchol;Yun, Changho
    • 한국해양공학회지
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    • 제36권1호
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    • pp.61-81
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    • 2022
  • The available underwater acoustic spectrum is limited. Therefore, it is imperative to avoid frequency interference from overlapping frequencies of underwater acoustic equipment (UAE) for the co-existence of the UAE. Cognitive technology that senses idle spectrum and actively avoids frequency interference is an efficient method to facilitate the collision-free operation of multiple UAE with overlapping frequencies. Cognitive technology is adopted to identify the frequency usage of UAE to apply cognitive technology. To this end, we investigated two principle underwater acoustic sources: UAE and marine animals. The UAE is classified into five types: underwater acoustic modem, acoustic positioning system, multi-beam echo-sounder, side-scan sonar, and sub-bottom profiler. We analyzed the parameters of the frequency band, directivity, range, and depth, which play a critical role in the design of underwater acoustic cognitive technology. Moreover, the frequency band of several marine species was also examined. The mid-frequency band from 10 - 40 kHz was found to be the busiest. Lastly, this study provides useful insights into the design of underwater acoustic cognitive technologies, where it is essential to avoid interference among the UAE in this mid-frequency band.

고 해상도 VCO 튜닝 기법을 이용한 MB-OFDM UWB용 주파수 합성기 (A Frequency Synthesizer for MB-OFDM UWB with Fine Resolution VCO Tuning Scheme)

  • 박준성;남철;김영신;부영건;허정;이강윤
    • 대한전자공학회논문지SD
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    • 제46권8호
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    • pp.117-124
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    • 2009
  • 본 논문에서는 UWB용 송수신기에서 LO 주파수를 생성해주는 주파수 합성기의 설계 결과를 보여주고 있다. 빠른 채널 스위칭 시간을 만족하기 위해서 1개의 PLL 과 여러 개의 분주기들과 SSB 믹서를 이용한 Sub-Band Generator로 구성하였으며, 전류 소모 및 면적을 최소화 하도록 설계하였다. 또한, 효과적인 주파수 플래닝을 통하여, 1개의 PLL로부터 생성된 636 MHz의 단일 주파수를 입력으로 받아 UWB Band Group 1 에 해당하는 3432 MHz, 3960 MHz, 4488 MHz의 중심 주파수를 발생시키는 Sub-Band Generator를 설계하였다. VCO의 튜닝 범위를 넓히면서도, 해상도를 높이기 위하여 MIM 커패시터, Varactor, DAC를 이용한 새로운 고 해상도 VCO 튜닝 기법을 제안하였다. 또한 본 논문에서 제안한 주파수 합성기의 구조는 기저 대역 모뎀의 ADC를 위한 클록을 공급하기 때문에 모뎀에서 ADC에 클록을 공급하기 위한 PLL을 제거할 수 있는 장점이 있다. VCO의 튜닝 범위는 1.2 GHz이며, 6336 MHz의 출력 주파수에서의 위상 잡음은 1 MHz 옵셋에서 -112 dBc/Hz 로 측정 되었다. UWB용 PLL 및 Sub-Band Generator는 0.13 ${\mu}m$ CMOS 공정으로 설계하였으며, 전체 Chip 면적은 2 ${\times}$ 2 mm2 이다. 전력 소모는 1.2 V 의 공급 전원에서 60 mW이다.

차세대 이동통신 시스템에 PAPR 감소기법을 적용한 다항식 사전왜곡 기법에 관한 연구 (A Study on Polynomial Pre-Distortion Technique Using PAPR Reduction Method in the Next Generation Mobile Communication System)

  • 김완태;박기식;조성준
    • 한국항행학회논문지
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    • 제14권5호
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    • pp.684-690
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    • 2010
  • 차세대 이동통신 시스템은 다양한 서비스의 융합과 멀티모드를 지원하기 위한 구조로 연구되고 있다. 또한 다양한 서비스를 제공받기 위한 사용자의 요구는 점차 증가되고 있으며, 서비스 지원을 위한 대용량 데이터 전송을 위한 많은 통신방식들이 출현하고 있다. 그 중 대표적인 시스템으로 OFDM(Orthogonal Frequency Division Multiplexing) 방식을 이용하는 WiBro(Wireless Broadband), WLAN(Wireless Local Area Network) 등이 있다. 하지만 차세대 이동통신 시스템에서는 하나의 단말로 OFDM 방식을 이용한 통신방식 이외 CDMA(Code Division Multiple Access), WCDMA(Wideband CDMA) 방식을 동시에 지원 받고자한다. 통합된 시스템은 SoC(System on Chip) 기술 적용으로 빠른 발전을 이루고 있지만, 무선통신 시스템에서 필수적으로 요구되는 요소 중 전력 증폭기의 비선형 특성으로 인한 신호의 왜곡을 유발시켜 인접채널 간섭을 성화 시키고 시스템의 효율을 떨어뜨리는 문제를 해결해야 한다. 전력증폭기의 문제점을 해결하기 위해 많은 선형화 기법들이 제시되었으며, 다항식 사전왜곡 기법은 증폭기로 입력되는 신호가 증폭기의 역 특성을 갖도록 하는 기법으로 다항식을 통하여 증폭기를 모델링하기 때문에 수렴 속도가 빠르고 다른 기법들과 비교하여 우수한 성능을 보인다. 본 논문에서는 차세대 이동통신 서비스를 위한 모뎀 구조를 제시하고 OFDM 방식 사용에 있어 발생 되는 PAPR(Peak-to-Average Power Ratio) 감소 기법을 적용한 후 다항식 사전왜곡 기법을 적용하여 차세대 이동통신 시스템을 분석하였다.

3D 위상 배열 안테나를 이용한 DoA 추정과 빔 형성시 각도 퍼짐에 의한 BER 성능 분석 (BER performance analysis by angle spreading effect in the DoA estimation and beam-forming using 3D phase array antenna)

  • 임승각;강대수
    • 한국인터넷방송통신학회논문지
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    • 제9권2호
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    • pp.137-144
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    • 2009
  • 본 논문은 GPS 신호를 기반으로하여 3D 배열 안테나를 사용한 전파의 도래각 (DoA : Direction of Arrival)을 추정한 후 빔 형성시의 재머 신호의 각도 퍼짐에의한 성능 비교에 관한 것이다. 배열 안테나를 사용하여 도래각을 추정한 후 공간 필터링에의해 도래 방향으로 빔을 형성하고, 다른 방향으로는 널링시킴으로서 수신 신호의 강도와 품질을 개선할 수 있지만 이 과정에서 다중 재머 신호에의한 각도 퍼짐으로 열화되는 성능이 얻어진다. 논문에서는 열화되는 성능의 비교를 위해 5 가지의 3D 배열 안테나를 제안하였고 도래각 추정은 MUSIC 알고리즘을, 빔 형성은 LCMV 알고리즘을 이용하였다. 또한 도래되는 재머 신호의 방위각과 앙각을 변화시키면서 BPSK 모뎀을 적용할 때 비트 오율을 계산하여 성능 비교를 하였다. 시뮬레이션 결과 Curved (B) 7-Element 형 3D 배열 안테나가 다른 안테나보다 성능이 가장 우월함을 알 수 있었다.

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당재길 걷고싶은 녹화거리 설계 (The Walkable Green Street Design for "Dangjae-Gil")

  • 김성균
    • 한국조경학회지
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    • 제30권1호
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    • pp.52-60
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    • 2002
  • This paper presents a streetscape design for "Dangiae-Gil"which is located at 126-1 Yangpyung-2dong, Yeongdeungpo-gu, Seoul and is about 500m in length and about 24m in width. The design goals are to make a green street on which people want to walk and people can walk and rest safely and pleasantly. To achieve these goals, concepts of environmentally-friendliness, placeness, safety, amenity, vitality, connectivity, and democracy are developed. For pedestrian safety, shared street concepts, such as crank, slalom etc. are adopted. The site is divided into 5 thematic spaces, such as "Village Entrance Space", "Culture Street", "Dangsan Park", "Nature Street", and "Ferry Space". The Village Entrance Space, which is an entrance of the Dangjae-Gil and a welcoming space, is for communicating information about the area. "Dangnamu"(zelkova tree) and signs are introduced here. The Culture Street is for experiencing past and present culture of the area. Colored tiles and plant boxes attached to benches are introduced. The Dangsan park is a sacred space where modem people can feel the sacredness of nature arid of being in a refuge. Dangjib, Dangnamu, multi-purpose plaza, athletic facilities, and playground for infants are introduced. The Nature Street is a space for feeling and teaming nature which has disappeared from the area leading to the river and a space for community participation. The elementary school walls were demolished and nature education spaces, such as butterfly and dragonfly garden, ecological pond, wildflower garden, etc., which are related to school education, are introduced. The Ferry Space is a space symbolizing a old ferry crossing and an entrance plaza to a bridge for "Sunyu-do\" . A boat-shaped deck, an elevator for handicap people, and parking space are introduced. In conclusion, sustainable management schemes for the site are suggested.sted.

보행 장애인을 위한 능동형 보행훈련 시스템 개발 및 평가 (The Development and Evaluation of the Active Gait Training System for the Patients with Gait Disorder)

  • 황성재;태기식;강성재;김정윤;황선홍;김한일;박시운;김영호
    • 대한의용생체공학회:의공학회지
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    • 제28권2호
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    • pp.218-228
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    • 2007
  • Modem concepts of gait rehabilitation after stroke favor a task-specific repetitive approach. In practice, the required physical effort of the therapists limits the realization of this approach. Therefore, a mechanized gait trainer enabling nonambulatory patients to have the repetitive practice of a gait-like movement without overstraining therapists was constructed. In this study, we developed an active gait training system for patients with gait disorder. This system provides joint movements to patients who cannot carry out an independent gait. It provides a normal stance-swing ratio of 60:40 using an eccentric configuration of two gears. Joint motions of the knee and the ankle were evaluated with using the 3D motion analysis system and compared with the results from the multi-body dynamics simulation. In addition, clinical investigations were also performed for low stroke patients during the 6-week gait training. Results from the dynamics simulation showed that joint movements of the knee and the ankle were affected by the gear size, the step length and the length of the foot plate, except the radius of curvature of the foot guide plate. Also, the 6-week gait training revealed relevant improvements of the gait ability in all low subjects. Functional ambulation category levels of subjects after training were 2 in three patients and 1 in a patient. The developed active gait trainer seems feasible as an adjunctive tool in gait rehabilitation after stroke.

농촌마을내부도로 수행가능 이용실태 분석 (Analysis on the Residents' Attitude to Rural Village Road's Functions)

  • 조은정;최수명;양소열;양원식;박용진
    • 농촌계획
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    • 제16권3호
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    • pp.131-141
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    • 2010
  • As a basic life-supporting infra in modem life, road should carry out various functions; transport, public linear network service, open activity space. Case study villages were divided into plan-based improved one(3 subtypes) and not one(4 subtypes). On total 21 case study villages($3{\times}7$ subtypes), questionnaire surveys were performed. Villagers' satisfaction level to road conditions in the plan-based improved villages showed much higher than not improved ones, which means that improvement of village roads be a vital subject in level-up of quality of rural life. Traffic function of village roads was responded as a principal one, while other various functions as between-villagers communication, car-parking and accommodation of public utilities were also required. In this viewpoint, village roads should be multi-purposedly developed in future. So, it was concluded that the road improvement strength would vary with geographical and topographical conditions of each village. Although villagers' unsatisfaction level on road service was very high, their demand level of and supporting will toward road improvement works have continuously increased, so, it would be considered to be the very time that full-fledged village road improvement policy be initiated.

2005년 S/S Trend에 나타난 Jeans의 패션경향과 패션상품 개발을 위한 디자인 연구 (A Study On Trend of S/S Jeans in 2005 by Using Fashion-ware Development Design)

  • 김영란;김병미
    • 한국의상디자인학회지
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    • 제8권2호
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    • pp.17-26
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    • 2006
  • As fashion is a reflection of a way of life, jean fashion seems to be a reflection of the background and process of social-human psychology. Modern jeans reflect personality and trend rather than traditional practicality as indicated by the concept and emphasis of fashion. Since the early 1990s, practical use of jeans has appeared consistently in products for interior use, various kinds of fashion-ware and fashion properties, as well as in fashion that is a conversion and interpretation of an outstanding fashion trend. And the search, providing that various symbols of jeans are sensualism, deviation, ostentation, amusement and multi-culture, shows that jeans represent the multifarious aspects of fashion culture. For the purpose and necessity of this search to meet different consumers' desires by the practical use of jeans and the development of fashion-ware. First, investigate the trend of jeans in 2005. Second, try to change the various uses of jeans by reflecting the trend of jeans. Finally, extend the range of choice by developing various goods. As a result, basic jeans have the strength of function, activity, and originality. Use of ornamental jeans can fully show their value as well as their emphasis of individuality in beauty. If we consider these points, we can minimize the limitations of jeans and make a practical use of the fashion trend, If we make the function of jeans stand out through the use of varieties of materials, the modem characteristic consumption will be met by the various change of use as well as by the clothes.

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