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Design of Smart Cold Chain Application Framework Based on Hadoop and Spark
Daesik Ko,Yoonsik Kwak,Dojin Choi,Seokil Song 보안공학연구지원센터 2015 International Journal of Software Engineering and Vol.9 No.12
A smart cold chain management is an information system which monitors and maintains the proper temperature of the products during whole cold chain, and analyzes data to report abnormal environmental status and risks to producers and consumers. In this paper, we propose an application framework for smart cold chain management system based on Hadoop, Spark and IoT (Internet of Things) techniques. The proposed application framework for smart cold chain provides PaaS (Platform as a Service) and IaaS (Infra as a Service) so as that smart cold chain management systems can be developed and operated with low cost and in short time. Also, the proposed application framework for smart cold chain allows the heterogeneous IOT devices such as RFID tags, WSN sensor nodes, BLE (Bluetooth Low Energy) sensor nodes and so on. We design PaaS and IaaS based on Hadoop and Spark to store the large amount of data stream on salable storage and process stream data in real time to detect events and assess risks in cold chain. Through generalizing the functions of existing cold chain management systems, common components in smart cold chain management systems are drawn.
Resolution Enhancement of Scanning Tomographic Acoustic Microscope System
Ko, Daesik The Acoustical Society of Korea 1996 韓國音響學會誌 Vol.15 No.e1
We proposed to use shear waves instead of longitudinal waves in a STAM (scanning tomographic acoustic microscope system) in which the specimens are solid. For any specimen with a shear modulus, mode conversion will take place at the water-solid interface. Some of the energy of the insonifying longitudinal waves in the water will convert to shear wave energy within the specimen. The shear wave energy is detectable and can be used for tomographic reconstruction. The resolution limitation of STAM depends on the available angular view and the acoustic wavelength. While wave transmission in most solid specimens is limited to about 20°for longitudinal waves, we show that it is about twice that high for shear waves. Since the wavelength of the shear wave is shorter than that of the longitudinal wave, we are able to achieve the high resolution. In order to compare the operation of a shear-wave STAM with that of the conventional longitudinal-wave STAM we have simulated tomographic reconstruction for each. Our simulation results with aluminum specimen and back-and-forth propagation algorithm showed resolution of a shear-wave STAM is better than that of a longitudinal-wave STAM.
Photon Multiplier Tube 의 디지털 동작을 위한 구동회로 설계
고대식(Daesik Ko) 한국정보기술학회 2009 Proceedings of KIIT Conference Vol.2009 No.-
본 연구에서는 구동회로에서 측정출력인 전류를 전압으로 변환시킨 후 이를 증폭하여 디지털시스템으로 동작하기 위해 필요한 증폭기를 설계하고 그 효과를 디지털 영상처리 시스템을 이용하여 분석하였다 . 본 연구에서는 제안된 PMT 와 증폭기의 성능을 분석하기 위하여 제안된 PMT 구동회로를 Bio-chip 분석장치에 적용하여 Chip 이미지를 읽어내는 장치를 구성하였다. 실험결과, DNA chip 이미지 처리에 필요한 충분한 S/N 특성을 나타내었으며 제안된 증폭기의 피드백 저항에 의하여 증폭기의 응답속도를 조절하여 이미지의 성능을 조절할 수 있도록 있음을 확인하였다.