• 융합신호처리학회논문지
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• 제10권2호
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• pp.100-105
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• 2009

방송용 디지털 콘텐츠의 저작권 보호를 위한 워터마킹은 실시간 처리가 가능하도록 만들어져야한다. 본 논문에서는 HD/SD 디지털 방송의 저작권 보호를 위한 실시간 비디오 워터마킹 칩 및 시스템을 제안한다. 제안한 칩은 ALTERA사의 STRATIX칩을 사용하여 하드웨어에 최적화된 워터마크 삽입 알고리듬을 이용하여 구현하였고, HD/SD 비디오 신호처리를 위한 시스템은 GENNUM사의 GS1560A와 GS1532를 사용하여 구현하였다. 구현 결과 원본 비디오와 워터마크 삽입된 비디오의 주관적인 화질에 대한 측정을 하였을 경우 워터마킹 때문에 약간의 인위적 화질 열화가 나타났다. 삽입된 워터마크는 A/D 변환과 같은 자연적인 비디오 공격 그리고 MPEG 압축 공격과 같은 강인성 실험 후에도 모두 추출되었다. 구현된 워터마킹 하드웨어 시스템은 고화질의 실시간 처리가 필요한 저작권 보호 시스템이 적용되는 방송국, 영화제작 환경에서 유용하게 사용될 것이다.

• Elastomers and Composites
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• 제52권4호
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• pp.266-271
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• 2017

This study describes the influence of the amount of curing agent and curing temperature on the kinetics of polyurethane elastomers. The urethane prepolymer series was prepared by reacting toluene diisocyanate with polytetramethylene ether glycol at $80^{\circ}C$ for 1 h, and 4,4'-methylene bis(2-chloroaniline) was used as the curing agent. The ratio of the amine group of the curing agent to the isocyanate group of the urethane prepolymer was controlled from 0.85 to 1.05 at curing temperatures ranging from 80 to $120^{\circ}C$. The curing rate of the urethane prepolymer was monitored by observing the change in heat flow during the curing process using differential scanning calorimetry (DSC). As either the content of curing agent or the curing temperature was higher, the conversion rate to the polyurethane elastomer was high. The DSC results were compared with those obtained from using real-time FT-IR.

• 방송공학회논문지
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• 제18권3호
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• pp.362-371
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• 2013

본 논문에서는 스테레오 카메라 추적을 이용한 모바일 3차원 디스플레이 상의 실시간 증강현실 프레임웍에 대하여 기술한다. 모델 기반 추적 방법에 기초하여 카메라 포즈는 스테레오 카메라 간의 기하 관계를 만족하도록 동시 추정된다. 동시 추정된 카메라 포즈를 통해 가상 콘텐츠는 교정된 스테레오 영상에 올바르게 증강된다. 스테레오 카메라 추적과 스테레오 영상 교정은 서로 다른 쓰레드에서 수행하고, 영상 형식 변환 및 스테레오 영상 교정은 GPU로 고속으로 처리함으로써 실시간으로 수행된다. 제안된 프레임웍은 스테레오 카메라와 3차원 디스플레이가 장착된 스마트폰에서 구현되었다.

• 전기전자학회논문지
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• 제17권4호
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• pp.550-558
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• 2013

본 논문에서는 다중 프로토콜 기반의 효율적인 하이브리드 조명관리 시스템 구현을 제안한다. 제안된 하이브리드 조명관리 시스템은 조명기기의 관리 및 제어를 위한 데이터 표시부와 데이터 변환 및 처리부, 게이트웨이의 통신부로 구성하여 설계하였다. 데이터는 실시간으로 저장이 가능하도록 DB를 설계하였고, 실시간 무선 원격제어 및 스케줄을 설정하여 관리하도록 구현하였다. 본 논문에서 제안된 효율적인 하이브리드 조명관리 시스템의 효율성 검증결과, 스마트 기기 및 포터블 PC 등과 연동하여 실시간 모니터링 및 원격 조명제어가 가능하였고, 결과적으로 에너지 절감 및 전기료 감소, 통신비용 감소 효과를 얻을 수 있었다.

• 한국전기전자재료학회논문지
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• 제29권5호
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• pp.284-288
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• 2016

Among the various physiological information that could be obtained from human body, heartbeat rate is a commonly used vital sign in the clinical milieu. Photoplethysography (PPG) sensor is incorporated into many wearable healthcare devices because of its advantages such as simplicity of hardware structure and low-cost. However, healthcare device employing PPG sensor has been issued in susceptibility of light and motion artifact. In this paper, to develop the real-time heart rate measurement device that is less sensitive to the external noises, we have fabricated an ultra-small wireless LC resonant pressure sensor by MEMS process. After performance evaluation in linearity and repeatability of the MEMS pressure sensor, heartbeat waveform and rate on radial artery were obtained by using resonant frequency-pressure conversion method. The measured data using the proposed heartbeat rate measurement system was validated by comparing it with the data of an commercialized heart rate measurement device. Result of the proposed device was agreed well to that of the commercialized device. The obtained real time heartbeat wave and rate were displayed on personal mobile system by bluetooth communication.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.410-413
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• 2007

Water vapor in the atmosphere is an influential factor of the hydrosphere cycle, which exchanges heat through phase change and is essential to precipitation. Because of its significance in altering weather, the estimation of water vapor amount and distribution is crucial to determine the precision of the weather forecasting and the understanding of regional/local climate. It is shown that it is reliable to measure precipitable water (PW) using long baseline (500-2000km) GPS observations. However, it becomes infeasible to derive absolute PW from GPS observations in Taiwan due to geometric limitation of relatively short-baseline network. In this study, a method of deriving Near-Real-Time PW from short baseline GPS observations is proposed. This method uses a reference station to derive a regression model for wet delay, and to interpolate the difference of wet delay among stations. Then, the precipitable water is obtained by using a conversion factor derived from radiosondes. The method has been tested by using the reference station located on Mt. Ho-Hwan with eleven stations around Taiwan. The result indicates that short baseline GPS observations can be used to precisely estimate the precipitable water in near-real-time.

• Journal of Electrical Engineering and Technology
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• 제1권4호
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• pp.409-413
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• 2006

This paper deals with the design and testing of a simulator system for microgrids with distributed generations. This system is composed of a Real Time Digital Simulator (RTDS) and a power amplifier. The RTDS parts are operated for real time simulation for the microgrid model and the distributed generation source model. The power amplifiers are operated fur amplification of the RTDS's simulated output signal, which is a node voltage of the microgrid and distributed generation source. In this paper, we represent an RTDS system design, specification and test results of a power amplifier and simulation results of a PV (Photovoltaic) system and wind turbine system. The proposed system is applicable for development and performance testing of a PCS (Power Conversion System) for renewable energy sources.

• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3417-3422
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• 2023

Recently, as the clinically positive biological effects of ultra-high dose rate (UHDR) radiation beams have been revealed, interest in flash radiation therapy has increased. Generally, FLASH preclinical experiments are performed using UHDR electron beams generated by linear accelerators. Real-time monitoring of UHDR beams is required to deliver the correct dose to a sample. However, it is difficult to use typical transmission-type ionization chambers for primary beam monitoring because there is no suitable electrometer capable of reading high pulsed currents, and collection efficiency is drastically reduced in pulsed radiation beams with ultra-high doses. In this study, a monitoring method using bremsstrahlung photons generated by irradiation devices and a water phantom was proposed. Charges collected in an ionization chamber located at the back of a water phantom were analyzed using the bremsstrahlung tail on electron depth dose curves obtained using radiochromic films. The dose conversion factor for converting a monitored charge into a delivered dose was determined analytically for the Advanced Markus® chamber and compared with experimentally determined values. It is anticipated that the method proposed in this study can be useful for monitoring sample doses in UHDR electron beam irradiation.

• 전기전자학회논문지
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• 제15권1호
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• pp.10-14
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• 2011

In this paper, we present an efficient hardware architecture of unrolling image mapper of catadioptric omnidirectional imaging systems. The catadioptric omnidirectional imaging systems generate images of 360 degrees of view and need to be transformed into panorama images in rectangular coordinate. In most application, it has to perform the panorama unrolling in real-time and at low-cost, especially for high-resolution images. The proposed hardware architecture adopts a software/hardware cooperative structure and employs several optimization schemes using look-up-table(LUT) of coordinate conversion. To avoid the on-line division operation caused by the coordinate transformation algorithm, the proposed architecture has the LUT which has pre-computed division factors. And then, the amount of memory used by the LUT is reduced to 1/4 by using symmetrical characteristic compared with the conventional architecture. Experimental results show that the proposed hardware architecture achieves an effective real-time performance and lower implementation cost, and it can be applied to other kinds of catadioptric omnidirectional imaging systems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.172-174
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• 2004

This paper proposes an integerized approach to solve PCA(Principal Component Analysis) feature extract procedure mainly used for the face recognition. A simple conversion to integer values has the risk to reduce the precision compared to that of the floating points operations. We integerize the PC variables by normalizing with the maximum of them, and show the efficiency of the proposed scheme by comparing the results to those of the float/double precisions. The integerized scheme is expected to be an efficient way for the real-time implementation of PCA's recognition stage, because integer operator is more desirable than floating point ones. Further research is to find a way to implement face detection and to measure the distances from the stored PCs for the full real-time face recognition.