Hyperspectral sensors acquire images in many, very narrow, contiguous spectral bands throughout the visible, near-infrared (IR), mid-IR and thermal IR portions of the spectrum, thus requiring large data storage on board the satellite and high bandwidth of the downlink transmission channel to ground stations. Image compression techniques are required to compensate for the limitations in terms of on-board storage and communication link bandwidth. In most remote-sensing applications, preservation of the original information is important and urges studies on lossless compression techniques for on-board implementation. This article first reviews hyperspectral spaceborne missions and compression techniques for hyperspectral images used on board satellites. The rest of the article investigates the suitability of the integer Karhunen-Loève transform (KLT) for lossless inter-band compression in spaceborne hyperspectral imaging payloads. Clustering and tiling strategies are employed to reduce the computational complexity of the algorithm. The integer KLT performance is evaluated through a comprehensive numerical experimentation using four airborne and four spaceborne hyperspectral datasets. In addition, an implementation of the integer KLT algorithm is ported to an embedded platform including a digital signal processor (DSP). The DSP performance results are reported and compared with the desktop implementation. The effects of clustering and tiling techniques on the compression ratio and latency are assessed for both desktop and the DSP implementation.
Vibration are found almost everywhere in rotating machines. Solving or reducing vibration in rotating machinery is difficult engineering task. The impact of exposure to the vibration operating the coconut scraper machine at conventional method will affected the health, exposure to the physical injury and exposure to the Hand-Arm Vibration Syndrome (HAVS). Basically, Vibration-induced White Finger (VWF) is the most condition the user will suffer when operating the vibration tools. The aim of this study was to measure the level of hand-arm vibration when operating using conventional method at coconut scraper machine and to analyse hand-arm vibration level during operating while using proposed adapter. During measurement, spindle speed of coconut scraper machine operating with 1485 RPM. In this study, for the first measurement between conventional method (free hand) and using glove (latex and leather glove) shows leather glove is better compared with others (free hand and latex glove). The reduction of hand-arm vibration in orthogonal direction (X, Y and Z- axis) are X-axis is 33%, Yaxis is 38% and Z-axis is 8%. The second measurement is using the proposed adapter that was designed and fabricated. The percentages reduction of the proposed adapter as compared to conventional method are X-axis is 38.3%, Y-axis is 51.9% and Zaxis is 25.5%
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