• 디지털산업정보학회논문지
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• 제14권3호
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• pp.39-44
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• 2018

Communication in real-time distributed system should have high reliability. To develop group communication Protocol with high reliability, potential fault should be known and when fault occurs, it should be detected and a necessary action should be taken. Existing detection method by Ack and Time-out is not proper for real time system due to load to Ack which is not received. Therefore, group communication messages from real-time distributed processing systems should be communicated to all receiving processors or ignored by the message itself. This paper can make be sure of transmission of reliable message and deadline by suggesting and experimenting fault detection technique applicable in the real time distributed system based on ring, and analyzing its results. The experiment showed that the shorter the cycle of the heartbeat signal, the shorter the time to propagate the fault detection, which is the time for other nodes to detect the failure of the node.

• 전기전자학회논문지
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• 제20권3호
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• pp.209-219
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• 2016

영상처리에 쓰이는 기계학습 방법 중 하나인 SVM은 일반화 능력이 뛰어나 객체를 분류하는 성능이 뛰어나다. SVM을 이용하여 객체를 분류하기 위해서는 여러 번의 MAC 연산을 반복해서 수행해야 한다. 하지만 영상의 해상도가 늘어남에 따라 분류를 해야 하는 개체가 늘어나게 되면 연산 시간이 증가하게 되어 실시간 처리를 요하는 고속 시스템에 사용하기 어렵다. 본 논문에서는 실시간 처리를 요하는 고속 시스템에서도 사용이 가능한 SVM 분류기 하드웨어 구조를 제안한다. 실시간 처리를 하는데 제한 요소가 되는 반복 연산은 병렬처리를 통하여 동시에 계산할 수 있게 하였고 다양한 종류의 특징점 추출기와도 호환이 가능하도록 설계하였다. 하드웨어 구현에 사용한 커널은 RBF 커널이며 커널 사용으로 생기는 지수 연산은 식을 변형하여 고정소수점 연산이 가능하도록 하였다. 제안한 하드웨어의 성능을 확인하기 위해 Xilinx ZC706 보드에 구현하였고 $1360{\times}800$ 해상도 이미지에 대한 수행 시간은 동작 주파수 100 MHz에서 약 60.46 fps로 실시간 처리가 가능함을 확인했다.

• Agricultural and Biosystems Engineering
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• 제7권1호
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• pp.8-12
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• 2006

This study was conducted to develop a real-time internal quality evaluation technique for Korean red ginseng using NIR spectroscopy while they were moving to be graded. Internal qualities of Korean red ginseng were defined by color, amount of white core and cavity in the red ginseng. To evaluate the internal quality, PLS (Partial Least Square) model was developed. Spectrum saturation can be occurred when most red ginseng has a sound internal quality expressed by higher light transmittance ratio, but that could not found in the ginseng of internal white core under the same light situation. And, if spectrum saturation is obtained, it is hard to identify the exact information of internal quality. In order to evaluate of the internal quality regardless of having internal normal core or white core, an integral time controlled method was used to obtain traditional spectrum. This procedure was applied in real-time process when red ginseng was moving to be graded in the line. Among the 450 samples including 223 internal normal ginsengs and 227 internal white core ginsengs, 315 ginsengs (70%) were used to develop a calibration model and 135 ginsengs were spent to validate the model. The result of quality evaluation by the model was very good showing SEP and bias were 0.3573 and 0.0310, respectively, and the accuracy was 95.6%.

• 한국기계가공학회지
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• 제9권3호
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• pp.76-82
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• 2010

A laborer always watched a process of production carefully but defective manufactures were inspected after press process. These inspections made a waste of human power and defective manufactures could make a serious damage of press mold. Therefore, AE(Acoustic Emission) system was introduced to prevention of the damage of the press molds, to a real time detection of defective manufactures and to save human power. AE system was introduced to solve this problem which is a detecting defective manufacture on real time and to prevent the damage of the press mold. In this research we get acoustic emission signal in accordance with weight and processing method of press by using AE sensor, Preamplifier, AE board signal board which occurs press processing and it analyzed various signal through using CMD8 software on the time. From the result, we found that the intensity and shape of the signal were changed according to the weight and processing type of the press. By using this special algorithm, it can judge the acoustic signal which occurs from press on real time.

• 한국공작기계학회논문집
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• 제15권4호
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• pp.44-48
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• 2006

Recently, demand the ultra precision product which is increasing rapidly is used extensively frontier industry field such as semi-conductor, computer, aerospace, precision machine. Ultra precision processing is the portion that is very needed to NT in the field of mechanical engineering. The latest date, together with radical advancement of electronic and photonics industry, necessity of ultra precision processing is on the increase for the manufacture of various kernel parts those are connected with these industrial fields. Specially, require motion accuracy of high resolution of nm order in stroke of hundreds millimeters according as diameter of processing object great and processing accuracy rises. In this case ,the response speed absolute delay because inertial mass of moving part is very large. Therefore, real time motion error compensation becomes very hardly. In this paper, we used ultra precision cutting unit(UPCU) to cope such problem. a UPCU is designed and tested to obtain sub-micrometer from accuracy in diamond turning of flat surfaces. The thermal growth spindle error is compensated for real time using a UPCU driven by piezoelectric actuator along with a laser encoder displacement sensor.

• 한국염색가공학회지
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• 제20권1호
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• pp.48-56
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• 2008

A real-time inspection system has been developed by combining CCD based image processing algorithm and a standard lighting equipment. The system was tested for defective fabrics showing nozzle contact scratch marks, which are one of the frequently occurring defects. Two algorithms used were compared according to both their processing time and detection rate. First algorithm (algorithm A) was based on morphological image processing such as dilation and opening for effective treatment of defective printing areas while second one (algorithm B) mainly employs well-defined edge detection technique based on canny detector and Zermike moment. It was concluded' that although both algorithms were quite successful, algorithm B showed relatively consistent performance than algorithm A in detecting complex patterns.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.619-621
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• 2013

본 논문은 TCP/IP 환경에서 서버-클라이언트(Server-Client)를 구축하고 이를 이용하여 실시간으로 음성 데이터를 처리하는 시스템을 제안한다. 서버에서는 음성 데이터를 재생하는 동시에 일정 간격으로 패킷(Packet)을 구성하여 클라이언트로 송신하고, 클라이언트는 수신받은 음성 데이터 패킷을 받아 재생한다. 일반적으로 TCP/IP 환경에서는 재생하는 속도보다 패킷을 수신하는 속도가 빠르기 때문에, 수신하는 음성 데이터를 단일로 재생할 경우 원활하지 않은 재생 현상을 보인다. 이를 해결하기 위해 본 논문에서는 더블 버퍼링(Double Buffering) 기법을 사용하였고, 이를 활용하여 실시간 음성 처리 및 재생을 가능하게 하였다.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제3권6호
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• pp.173-178
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• 2014

제시된 스케줄링 기법은 병렬처리 기법을 활용하여 실시간 작업들의 데드라인 제약과 결함 포용 제약을 만족하면서 멀티코어 프로세서의 에너지 소모 효율성을 향상시켰다. 최소 에너지 소모량 스케줄을 찾는 것은 NP-hard 문제이므로, 제시된 기법은 다항식의 시간 내에 최소 에너지 소모량에 근접하는 스케줄을 찾는다. 제시된 기법은 연관된 최신 기법과 비교하여 높은 병렬처리 속도는 물론 낮은 병렬처리 속도에서도 에너지 소모량이 현격하게 낮았으며, 에너지 소모량을 최대 86% 줄였다.

• Current Optics and Photonics
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• 제2권5호
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• pp.453-459
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• 2018

We have developed a high-performance signal-processing and image-rendering heterogeneous computation system for optical coherence tomography (OCT) on mobile processor. In this paper, we reveal it by demonstrating real-time OCT image processing using a Snapdragon 800 mobile processor, with the introduction of a heterogeneous image visualization architecture (HIVA) to accelerate the signal-processing and image-visualization procedures. HIVA has been designed to maximize the computational performances of a mobile processor by using a native language compiler, which targets mobile processor, to directly access mobile-processor computing resources and the open computing language (OpenCL) for heterogeneous computation. The developed mobile image processing platform requires only 25 ms to produce an OCT image from $512{\times}1024$ OCT data. This is 617 times faster than the naïve approach without HIVA, which requires more than 15 s. The developed platform can produce 40 OCT images per second, to facilitate real-time mobile OCT image visualization. We believe this study would facilitate the development of portable diagnostic image visualization with medical imaging modality, which requires computationally expensive procedures, using a mobile processor.

• Journal of Positioning, Navigation, and Timing
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• 제12권1호
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• pp.75-81
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• 2023

In this study, we design an optimized Graphics Processing Unit (GPU)-based GNSS signal processing technique with the goal of designing and implementing a GNSS Software Defined Receiver (SDR) that can operate in real time all-in-view mode under multi-constellation and multi-frequency signal environment. In the proposed structure the correlators of the existing GNSS SDR are processed by the GPU. We designed a memory structure and processing method that can minimize memory access bottlenecks and optimize the GPU memory resource distribution. The designed GNSS SDR can select and operate only the desired GNSS or desired satellite signals by user input. Also, parameters such as the number of quantization bits, sampling rate, and number of signal tracking arms can be selected. The computing capability of the designed GPU-based GNSS SDR was evaluated and it was confirmed that up to 2400 channels can be processed in real time. As a result, the GPU-based GNSS SDR has sufficient performance to operate in real-time all-in-view mode. In future studies, it will be used for more diverse GNSS signal processing and will be applied to multipath effect analysis using more tracking arms.