• 한국산업정보학회논문지
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• 제20권4호
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• pp.67-73
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• 2015

최근 재료의 물성평가에 있어 표면마찰 특성이 많이 요구되고 있는 바, 본 연구에서는 휴대 가능한 보급형 마찰계수 시험기의 개발을 다루며, 이는 기구 설계 및 적용, 측정회로의 설계 및 배치, 마이크로프로세서 기반 펌웨어의 구성을 포함한다. 또한 기존의 규격 시험기와 성능 비교를 통하여 본 휴대용 마찰계수 시험기의 실 적용성을 보였다.

• 한국통신학회논문지
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• 제33권5A호
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• pp.487-493
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• 2008

In this paper, we consider coded layered space-time architecture in MIMO-OFDM channels. Vertical Bell Lab Layered Space-Time(V-BLAST) scheme employing ordered successive interference cancellation(OSIC) algorithm provides very high spectral efficiency with low computational complexity. However, the error propagation is a major drawback constraining the overall performance of the V-BLAST system significantly. Based on this problem, we derive an improved detector using soft bit log-likelihood ratio(LLR) value. Simulation results show that the proposed detector outperforms the conventional V-BLAST scheme under spatially uncorrelated as well as correlated fading channels.

• Journal of Information Technology Applications and Management
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• 제13권4호
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• pp.257-271
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• 2006

Recently, flash memories are one of best media to support portable computer's storages in mobile computing environment. The features of non-volatility, low power consumption, and fast access time for read operations are sufficient grounds to support flash memory as major database storage components of portable computers. However, we need to improve traditional Indexing scheme such as B-Tree due to the relatively slow characteristics of flash operation as compared to RAM memory. In order to achieve this goal, we devise a new indexing scheme called F-Tree. F-Tree improves tree operation performance by compressing pointers and keys in tree nodes and rewriting the nodes without a slow erase operation in node insert/delete processes. Based on the results of the performance evaluation, we conclude that F-Tree indexing scheme outperforms the traditional indexing scheme.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 추계학술대회
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• pp.938-941
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• 2011

본 연구에서 디지털 방송 수신 및 저장을 위하여 이동식 멀티미디어 플레이어를 이용하여 도킹스테이션을 설계하였다. 디지털 방송 콘텐츠 수신 및 저장은 셋탑박스를 이용하며 이동식 미디어 플레이어와 탈부착 기능을 부가하였고, 이동식 미디어플레이어의 OS는 안드로이드를 사용하였다. 구현결과 이 시스템은 디지털방송, 지상파, 위성방송, DMB 등의 수신이 가능하며 비디오 영상은 실시간으로 저장된다.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.559-562
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• 2008

In this paper we propose a lock-in detection method for portable sensor systems and demonstrate with the portable detection module that has high sensitivity and robustness against the noise. The simple portable sensor module is manufactured using MCU(Micro Contorl Unit), OPAMP, MOSFET and a pair of infrared sensor. Manufactured sensor module is testified in the noisy environment caused by an external light and an white noise source. Without any type of band pass filters, we recover a signal of 33 $mV_{p-p}$ in 80 $mV_{p-p}$ white noise and get the DR(Dynamic Reserve) of 14 dB.

• Journal of Power Electronics
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• 제13권6호
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• pp.1051-1057
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• 2013

This paper proposes an implementable sun tracking algorithm for portable systems powered by alternative energy sources. The proposed system uses a 2-axis tilt sensor and a 3-axis magnetic sensor to measure the orientation and posture of the system, according to a horizon coordinates system, and compensate for tilt effects. Then, through an astronomical calculation, using the present time and position information obtained from GPS sensors, the azimuth and altitude of the sun in that location is calculated and converted to portable sun tracking system coordinates and used to control the A- and C-axes of the system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 심포지엄 논문집 정보 및 제어부문
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• pp.147-149
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• 2004

Although most of the people have studied English for a long time, their English conversation capability is low. When we provide them portable conversational-type English learners by the application of computer and information process technology, such portable learners can be used to enhance their English conversation capability by their conventional conversation exercises. The core technology to develop such learner is the development of a voice recognition and synthesis module under an embedded environment. This paper deals with voice recognition and synthesis, prototype of the learner module using a DSP(Digital Signal Processing) chip for voice processing, voice playback function, flash memory file system, PC download function using USB ports, English conversation text function by the use of SMC(Smart Media Card) flash memory, LCD display function, MP3 music listening function, etc. Application areas of the prototype equipped with such various functions are vast, i.e. portable language learners, amusement devices, kids toy, control by voice, security by the use of voice, etc.

• 한국정보기술학회 영문논문지
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• 제10권1호
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• pp.99-109
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• 2020

As environmental pollution has become severe due to the rapid increase in pollutant generation in the air, measurement, collection, and analysis of atmospheric environment information plays an important role. However, it is difficult to measure the high-resolution and real-time atmospheric environment of the cities and tourist spots with high population mobility only by measuring equipment of stationary measuring stations. Therefore, this paper proposes a portable atmospheric environment measurement system for real-time measurement and monitoring of atmospheric environment information. The proposed system is a portable client with a low-power wireless communication method. It is possible to reliably transmit and receive the measured data through a multi-threaded server to monitor the trend of pollutants in the air in real-time.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1989년도 추계 학술대회지
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• pp.42-43
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• 1989

• 방재와보험
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• 통권106호
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• pp.59-63
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• 2005

이 글에서는 ISO 11602-1, Fire Protection - Portable and Wheeled Fire Extinguishers - part 1 : Selection and installation(2000년판)과 NFPA 10, Standard for Portable Fire Extinguishers(2003년판)에 설명된 소화기 선택과 배치에 대한 개괄을 한다.