Jerome J. Tiemann

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This paper presents a new distributed multifrontal sparse matrix decomposition algorithm suitable for message passing parallel processors. The algorithm uses a nested dissection ordering and a multifrontal distribution of the matrix to minimize interprocessor data dependencies and overcome the communication bottleneck previously reported for sparse matrix(More)
A theory is provided for the detection efficiency of diffuse light whose frequency is modulated by an acoustical wave. We derive expressions for the speckle pattern of the modulated light, as well as an expression for the signal-to-noise ratio for the detector. The aim is to develop a new imaging technology for detection of tumors in humans. The acoustic(More)
Two-dimensional echocardiography has been used to image the left main coronary artery. We have successfully imaged the left main coronary artery in 16 of 19 patients with left main coronary artery disease (LMCAD) and in 14 of 18 control patients using a dynamically focused 3-1/2 MHz experimental phased array sector scanner. Images were displayed with(More)
New military communications require increased versatility for the transmission of a wide range of data, voice and images. There are many algorithms needed for communication like FFT (Fast Fourier Transform), DCT (Discrete Cosine Transforms), Viterbi coders and decoders, trellis techniques etc. Advances in VLSI technology continue to improve the quality of(More)
The analysis and processing of biological signals is often hampered by the contamination of these low frequency, often low amplitude waveforms by motion artifact in fluid-filled catheter systems and skin electrodes, power line hum, and so on. Although noise suppression techniques have relied upon low pass filtration of the analog signals with active or(More)
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