• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2002년도 추계학술발표논문집 (중)
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• pp.1371-1374
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• 2002

본 논문에서는 내장형 리눅스를 기반으로 무선 네트웍과 실시간 음성처리 VoIP 와의 연동시스템을 설계 구현한다. 설계 구현하는 시스템의 하드웨어 스펙은 Motorola-XPC860 프로세서를 기반으로 설계되었으며, 음성 코덱칩을 사용하여 실시간으로 음성데이터를 처리하도록 설계하였다. 또한 2.4GHz 무선 통신 규약인 Bluetooth 를 무선 네트웍 인터페이스로 사용하였다. 실시간 음성데이터의 효과적인 처리를 위하여 실시간 운영 체제인 RTLinux 를 사용하였으며, 무선 네트워크의 동시다중 서비스 지원을 위해 커널레벨의 문자 디바이스 형태로의 Bluetooth 인터페이스 구현에 대해 살펴보도록 하겠다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제5권3호
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• pp.189-195
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• 2005

One of the major components of any pervasive system is its proactive behavior. Various models have been developed to provide system wide changes which would enable proactive behavior. A major drawback of these approaches is that they do not address the need to make use of existing applications without modifying the applications. To overcome this drawback, a middleware architecture called 'Concord' is proposed. Concord is based on a simple model which consists of Lookup Server and Database. The rewards for this simple model are many. First, Concord uses the existing computing infrastructure. Second, Concord standardizes the interfaces for all services and platforms. Third, new services can be added dynamically without any need for reconfiguration. Finally, Concord consists of Database that can maintain and publish the active set of available resources. Thus Concord provides a solid system for integration of various entities to provide seamless connectivity and enable proactive behavior.

• 전자통신동향분석
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• 제19권5호통권89호
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• pp.87-94
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• 2004

기존의 통신 시스템에 비해 매우 넓은 대역폭을 사용하는 UWB 시스템은 기존의 유선장치를 무선장치로대치할 수 있는 유일한 고속 무선 전송기술로서 가정내 멀티미디어 데이터 전송을 위한 근거리 무선 홈네트워크 기술로 부각되고 있다. 현재 IEEE802.15의 TG3a에서는 UWB 기술을 이용한 고속 WPAN의 물리계층에 대한 표준화가 진행되고 있으며, MBOA에서 주도하고 있는 MB-OFDM 시스템과 Motorola에서 주도하고 있는 DS-UWB 시스템의 2가지 제안서로 압축되어 표준화가 진행되고 있다. 본 논문에서는 현재까지의 표준화 진행 상황 및 양측에서 제안된 UWB 물리계층 표준화 기술 동향에 관하여 살펴본다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.417-420
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• 2002

In this paper, we implemented a SDH synchronous network system based on ITU-T recommendation G.707 - Network node interface for the synchronous digital archy(SDH). For the system, we used signal processing SDH ASIC, and designed a FPGA_Control chip for various signal control and a FPGA_Alignment cllip for data alignment using YHDL(Very high speed integrated circuit Hardware Description Language). For system monitoring, an operation system was developed using ANSI C and executed in CPU (Motorola MPC-860). The system was evaluated by using ANT-20 for data transmission error defection, jitter detection, pointer chocking, and overhead determination.

• 산업경영시스템학회지
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• 제30권4호
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• pp.1-12
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• 2007

Motorola developed the framework of six sigma in 1987. In these days, many companies adapt this powerful tool. In 1996, six sigma was introduced to the Korean companies as a management innovation tool. This study shows case study of 'Champion Project' which was adopted on one Korean company. The champion project is directed by the leader who has a champion belt. The project focus on the processes optimization problem or resource concentration problem to solve critical issues inside of the process. This case study shows the result of champion project. The effect was encouraging in the aspect of effectiveness and efficiency. The most important point of this study is an introduction of the third generation six sigma which was successively adopted on the Korean company.

• Journal of Communications and Networks
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• 제8권3호
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• pp.297-305
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• 2006

High-rate wireless personal area network (HR-WPAN) has been standardized by the IEEE 802.15.3 task group (TG). To support multimedia services, the IEEE 802.15.3 TG adopts a time-slotted medium access control (MAC) protocol controlled by a central device. In the time division multiple access (TDMA)-based wireless packet networks, the packet scheduling algorithm plays a key role in quality of service (QoS) provisioning for multimedia services. In this paper, we propose an adaptive cross-layer packet scheduling method for the TDMA-based HR-WPAN. Physical channel conditions, MAC protocol, link layer status, random traffic arrival, and QoS requirement are taken into consideration by the proposed packet scheduling method. Performance evaluations are carried out through extensive simulations and significant performance enhancements are observed. Furthermore, the performance of the proposed scheme remains stable regardless of the variable system parameters such as the number of devices (DEVs) and delay bound.

• Journal of information and communication convergence engineering
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• 제2권2호
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• pp.76-79
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• 2004

The DS-SS (Direct Sequence Spread Spec1nun) transmitter is part of a low data rate (∼150 kbps - burst rate and 64 bps - average data rate) wireless communication system. It is traditionally implemented using Digital Signal processing chip (DSP). However, with rapid increase in variety of services through cell phones, such as, web access, video transfer, online games etc. demand for higher rate is increasing steadily. Since the chip rate and thereby the sampling rate requirements of the system are fairly high, the transmitter should implemented using Field programmable Gate Arrays FPGAs instead of a DSP. This paper shows the steps taken to get a working prototype of the transmitter unit on a FPGA based platform.

• 소음진동
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• 제9권2호
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• pp.265-272
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• 1999

A LMS algorithms has been widely used for an adaptive filter algorithm in active noise control systems. But this algorithm has poor convergence and it is very difficult to select optimal convergence parameters in this algorithm. In this paper, a fuzzy LMS algorithm where the convergence parameters are computed using a fuzzy logic controller was proposed. A proposed algorithm was applied to active noise control system in HVAC(central Heating Ventilation and Air Conditioning) ducts. The experimental ducts and experimental apparatus were designed and manufactured for experiments, and the modelling of the experimental ducts was also performed for computer simulations. Computer simulations and experiments were performed to show the effectiveness of a proposed algorithm.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2009년도 춘계학술발표대회
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• pp.706-709
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• 2009

The informatization of Korea is accompanied by the great growth of new strategic export industry, as of mobile phone or semiconductor LCD. Speaking to the situation of mobile phone, Motorola swept over the American domestic market in the beginning of 1990s, digital mobile communication as CDMA developed swiftly in Korea. In 1996, the first year's CDMA users of Samsung were merely one million, nevertheless, the world's sales in the first half of this year is up to 92 million. In this p aper I design 3D application based on J2ME and implement a freely removable 3D object which happened in a 3D scen e by receiving the keyboard response of mobile device with WTK (Wireless ToolKit) simulator. It contains benefits of improvement of relative speed and high-level functionality such as scene graph, keyframe animation, etc.

• 한국정보통신학회논문지
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• 제3권3호
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• pp.517-531
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• 1999

본 논문에서는 INMARSAT-M형 송신기에 사용되는 L-BAND(1626.5-1646.5 MHz)용 2단 가변이득 전력 증폭기를 연구 개발하였다. 2단 가변이득 전력증폭기는 구동증폭단과 전력증폭단에 의해 고출력 모드일 때 +42 dBm, 저출력 모드일 때는 +36 dBm의 전력으로 증폭되며, 각각에 대해 상한 +1 dBm과 하한 -2 dBm의 오차를 허용한다. 제작의 간편성 때문에 전체 2단 가변이득 전력증폭기를 크게 구동증폭단과 전력증폭단 두 부분으로 나누어 구현하였으며, 전력증폭부를 구동하기 위한 구동단은 HP사의 MGA-64135와 Motorola사의 MRF-6401을 사용하였으며, 전력증폭단은 ERICSSON사의 PTE-10114와 PTF-10021을 사용하여 RF부, 온도보상회로 및 출력 조절회로를 함께 집적화 하였다. 이득조절은 구동증폭단의 MGA-64135의 바이어스 전압을 조절하는 방법을 제시하였으며, 실험 결과와 잘 일치하였다. 제작된 2단 가변이득 전력증폭기는 20 MHz대역폭 내에서 소신호 이득이 42 dB와 36 dB 이상, 입ㆍ출력 정재파비는 1.5:1 이하, 5 dBm의 $P_{1dB}$. $P_{ldB}$출력레벨에서 3 dB Back off 시켰을 때 32.5 dBc의 I $M_3$를 얻었다. 1636.5 MHz 주파수에 대해 출력전력은 43 dBm과 37 dBm으로서 설계시 목표로 했던 최대 출력전력 20 Watt를 얻었다.다.다.