Previous work has shown that left atrial pressure can be non-invasively measured from mitral regurgitation velocity at the onset of left ventricular ejection. Here, the authors introduce a computer assisted approach t...
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Previous work has shown that left atrial pressure can be non-invasively measured from mitral regurgitation velocity at the onset of left ventricular ejection. Here, the authors introduce a computer assisted approach to computing left atrial pressure based on this technique which reduces the need for manual measurement of times and velocities from the Doppler spectra. This process includes the creation of a signal-averaged mitral regurgitation Doppler spectrum that combines data from multiple beats into a single, more coherent spectrum, with a more clearly delineated velocity envelope.
We present a pulse-driven asynchronous logic gate family based on a high-speed, low-power Josephson-junction device of rapid single-flux-quantum (RSFQ) circuits. Dual-rail logic is used and clock-free operation is rea...
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We present a pulse-driven asynchronous logic gate family based on a high-speed, low-power Josephson-junction device of rapid single-flux-quantum (RSFQ) circuits. Dual-rail logic is used and clock-free operation is realized. The proper operation of the circuits is confirmed by the numerical simulation which shows logic delays are about 60 ps for an AND and about 80 ps for an XOR. Power consumption is estimated to be 10 /spl mu/W/gate.
Harder, new requirements are appearing in the area of database systems. The popularity reached by parallel database systems during the past decade, due to their high performance and scalability characteristics, should...
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Harder, new requirements are appearing in the area of database systems. The popularity reached by parallel database systems during the past decade, due to their high performance and scalability
Harder, new requirements are appearing in the area of database systems. The popularity reached by parallel database systems during the past decade, due to their high performance and scalability
Proper distribution of operations among parallel processors in a large scientific computation executed on a distributed-memory machine can significantly reduce the total computation time. In this paper, we propose an ...
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Proper distribution of operations among parallel processors in a large scientific computation executed on a distributed-memory machine can significantly reduce the total computation time. In this paper, we propose an operation called simultaneous parallel reduction(SPR), that is amenable to such optimization. SPR performs reduction operations in parallel, each operation reducing a one-dimensional consecutive section of a distributed array. Each element of the distributed array is used as an operand to many reductions executed concurrently over the overlapping array's sections. SPR is distinct from a more commonly considered parallel reduction which concurrently evaluates a single reduction. In this paper we consider SPR on Single Instruction Multiple Data (SIMD) machines with different interconnection networks. We focus on SPR over sections whose size is not a power of 2 with the result shifted relative to the arguments. Several algorithms achieving some of the lower bounds on SPR complexity are presented under various assumptions about the properties of the binary operator of the reduction and of the communication cost of the target architectures.
Guaranteeing reproducibility and minimizing probe effects are major issues in the parallel program debugging. The paper suggests a new debugging method, called the Detect and Reproduce method, for message-based parall...
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Guaranteeing reproducibility and minimizing probe effects are major issues in the parallel program debugging. The paper suggests a new debugging method, called the Detect and Reproduce method, for message-based parall...
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ISBN:
(纸本)0818671718
Guaranteeing reproducibility and minimizing probe effects are major issues in the parallel program debugging. The paper suggests a new debugging method, called the Detect and Reproduce method, for message-based parallel programs. The proposed method is designed to guarantee the reproducible behaviors of a target program and to alleviate probe effects by reducing both the number of the probes to be inserted into a program and the amount of information gathered by those probes. The proposed method achieves such effects by employing a static analysis technique to detect nondeterminacy. By detecting nondeterminacy before running the program, only a small number of probes are required to assure reproducibility. To analyze message-based programs statically, an MHB (minimal happened before) model is designed to catch the synchronization structures and algorithms have been developed to locate nondeterminacy based on the MHB model. Utilizing the analysis results, probes are inserted only into the places where nondeterminacy is likely to take place.
The article discusses various reports published within the issue, including one by James B. Baty, II and Ronald M. Lee on electronic commerce and another by Minder Chen on executive information systems.
The article discusses various reports published within the issue, including one by James B. Baty, II and Ronald M. Lee on electronic commerce and another by Minder Chen on executive information systems.
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