摘要 :
We present a novel technique called probing cluster terrain(PCT)useful for exploring the terrain(shape and size) of individual clusters contained in input X={x_i, i= 1,. . ., n}, even if X was not previously partitioned. A covaria...
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We present a novel technique called probing cluster terrain(PCT)useful for exploring the terrain(shape and size) of individual clusters contained in input X={x_i, i= 1,. . ., n}, even if X was not previously partitioned. A covariance matrix C(訽j) is employed as an explorer to probe the terrain of the cluster centered at υ_j. Associated with C~t(υ_j)is a ring formed with the formula for Mahalanobis distance. The kernel of PCT is an alternating process that minimizes a well- defined objective function J. The most intriguing behavior of PCT is that the ring actually expands to discover data points of the cluster in the course of minimizing J.
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摘要 :
We propose a simple distance-vector protocol for routing in networks having unidirectional links. The protocol can be seen as an adaptation for these networks of the strategy as used in the popular RIP protocol. The protocol compr...
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We propose a simple distance-vector protocol for routing in networks having unidirectional links. The protocol can be seen as an adaptation for these networks of the strategy as used in the popular RIP protocol. The protocol comprises two main algorithms, one for collecting "from" information, and the other one for generating and propagating "to" information. Like the RIP protocol, this one can handle dynamic changes and tolerate node and link failures in the network.
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摘要 :
The ultra-fine HNS (2,2',4,4',6,6'-hexanitrostilbene) with desired properties is needed for military and civilian applications because of its reliable threshold energy to short impulse shock waves and its excellent thermal and sho...
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The ultra-fine HNS (2,2',4,4',6,6'-hexanitrostilbene) with desired properties is needed for military and civilian applications because of its reliable threshold energy to short impulse shock waves and its excellent thermal and shock stability. This paper reports on prefilming twin-fluid nozzle assisted precipitation (PTFN-P) to obtain ultra-fine HNS explosive with high specific surface area (SSA), high purity, and narrow particle size distribution. The properties of ultra-fine HNS have been confirmed by SEM, BET, HPLC, XRD, DSC and TGA-SDTA. SEM photograph revealed that the PTFN-P process offers ellipsoid crystalline morphology with particle size of 90-150 nm. The BET and Langmuir SSA of nanocrystalline HNS with purity of 99.44 wt.% were determined to be 19.28 m~2/g and 29.26 m~2/g, respectively. The XRD peaks of nanocrystalline HNS seemed to have similar diffraction angles as those of synthesized HNS, and the weakening of peak strength was observed apparently. DSC results of the nanocrystalline HNS showed that the exothermic decomposing at the temperature range of 323-398 ℃. Furthermore, HNS samples were submitted to impact and small scale gap test and the results indicated that nanocrystalline HNS is less sensitive than synthesized HNS (50 μm) to impact and shock stimuli.
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摘要 :
The applicability of the current LWR core analysis method to C5G7 2D and 3D problems is studied. It is found that the conventional two group homogenization method does not work. However surprisingly good results can be obtained if...
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The applicability of the current LWR core analysis method to C5G7 2D and 3D problems is studied. It is found that the conventional two group homogenization method does not work. However surprisingly good results can be obtained if two-group collapsing is not done in the conventional homogenization process. With a minor modification of the homogenization process to address the reflector influence, results comparable to 3D transport calculation can be obtained. Considering its simplicity and much faster speed compared to whole core transport calculation, the proposed method is of good potential.
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摘要 :
Organic matter based battery materials have attracted large
interest due to their inherent ability to provide an environmentally
benign alternative to inorganic batteries because organic materials
can be produced from renewable re...
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Organic matter based battery materials have attracted large
interest due to their inherent ability to provide an environmentally
benign alternative to inorganic batteries because organic materials
can be produced from renewable resources via eco-efficient
processes. The development of organic battery materials rely on
several key factors that need to be resolved, the most important being
dissolution problems, limited electronic conductivity, degradation of
active material and slow redox kinetics. Conducting polymers are
insoluble in most electrolytes, they are electronically conducting and
show fast redox conversion but are, to some extent, unstable and
have insufficient charge capacities for battery applications.
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