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71.
A planar monotone circuit (PMC) is a Boolean circuit that can be embedded in the plane and that contains only AND and OR
gates. A layered PMC is a PMC in which all input nodes are in the external face, and the gates can be assigned to layers in
such a way that every wire goes between gates in successive layers. Goldschlager, Cook and Dymond, and others have developed
NC
2
algorithms to evaluate a layered PMC when the output node is in the same face as the input nodes. These algorithms require
a large number of processors (Ω(n
6
), where n is the size of the input circuit).
In this paper we give an efficient parallel algorithm that evaluates a layered PMC of size n in time using only a linear number of processors on an EREW PRAM. Our parallel algorithm is the best possible to within a polylog
factor, and is a substantial improvement over the earlier algorithms for the problem.
Received April 18, 1994; revised April 7, 1995. 相似文献
72.
73.
74.
The authors describe the development of critical pathways for ambulatory obstetric case management. When case management was identified as needed, but published work in outpatient obstetrics could not be found, four nurses used this opportunity to design a cost-effective system leading to quality outcomes. The driving force was the need for a format that directed comprehensive consistent care delivered by a large multidisciplinary health care team. Design issues included capturing leading edge standards of care and user friendly formats for all caregivers. Throughout a period of 2 years, a trifold format was developed for all obstetric patients, and 15 bifold formats were developed for patients with specific high-risk diagnoses. The format design facilitated cost-effective quality care and is expected to improve patient outcomes. A research study has been initiated to measure effectiveness of the design. 相似文献
75.
R Vijaya R Gupta G Panda K Ravishankar G Kumaramanickavel 《Canadian Metallurgical Quarterly》1997,52(6):427-431
When oxygen delivery (DO2) critically decreases, oxygen consumption (VO2) becomes supply dependent. We examined whether end-tidal PCO2 (PetCO2) would identify supply dependency during shock. Five dogs (Group I) underwent progressive hemorrhage to decrease DO2 until they could no longer maintain a stable blood pressure. Five additional animals (Group II) were bled until VO2 decreased to 70% of baseline, followed by resuscitation. The PetCO2 versus time inflection point was compared with the DO2 at onset of supply dependency (DO2crit). DO2crit for Groups I and II were 6.9 +/- .4 and 8.1 +/- 1.3, respectively (p = NS), and not statistically different from the DO2 values at which PetCO2 decreased (6.6 +/- .7 and 6.3 +/- .7 mL/kg per min, respectively). AT constant minute volume, PetCO2 effectively indicated the onset of supply dependency and rapidly increased during resuscitation, paralleling the changes in VO2 in this model of hemorrhagic shock. 相似文献
76.
Multistoreyed building frames are analysed in a single step on the assumption that the frame is subjected to design load once the whole frame is constructed completely. In fact the dead load due to the various members and finishing items are imposed in stages as the frame is constructed storey by storey.In this paper, a model of the sequence of construction has been assumed and two multistoreyed frames of different configurations have been analysed. The results of analyses along with a comparison with conventional one step analysis have been presented. The effect of sequence of construction due to the self-weight of members has been studied and its effect on the overall design forces has also been highlighted. 相似文献
77.
Ribosomal RNA (rRNA) synthesis, the initiation of which is an early major event during the transformation of iris into lens in the newt, was characterized in the TVI cell-line derived from the eastern North-American newt Notophthalmus viridescens. Employing the technique of polyacrylamide gel electrophoresis, molecular-weight measurements were made on newt rRNAs using Xenopus laevis and E. coli rRNAs as standards. The molecular weights of N. viridescens 28S and 18S rRNA were found to be 1.4 X 10(6) and 0.7 X 10(6) respectively. The precursor to these RNAs had a molecular weight of 3.1 X 10(6). Three probable intermediates in the processing of precursor to mature rRNA were also identified. On the basis of the molecular weights of all species of RNA identified, a processing pathway, similar to that of Xenopus, has been suggested. Some unusual features in the kinetics of precursor rRNA labelling and processing suggest the possibility that newt-cell rRNA synthesis may be controlled by the availability of essential amino acids in a manner similar to that observed in mammalian cells. A possible relationship between the availability of essential amino acids, the initiation of rRNA synthesis in the newt iris, and the control of lens regeneration is discussed. 相似文献
78.
Face recognition on mobile devices, such as personal digital assistants and cell phones, is a big challenge owing to the limited computational resources available to run verifications on the devices themselves. One approach is to transmit the captured face images by use of the cell-phone connection and to run the verification on a remote station. However, owing to limitations in communication bandwidth, it may be necessary to transmit a compressed version of the image. We propose using the image compression standard JPEG2000, which is a wavelet-based compression engine used to compress the face images to low bit rates suitable for transmission over low-bandwidth communication channels. At the receiver end, the face images are reconstructed with a JPEG2000 decoder and are fed into the verification engine. We explore how advanced correlation filters, such as the minimum average correlation energy filter [Appl. Opt. 26, 3633 (1987)] and its variants, perform by using face images captured under different illumination conditions and encoded with different bit rates under the JPEG2000 wavelet-encoding standard. We evaluate the performance of these filters by using illumination variations from the Carnegie Mellon University's Pose, Illumination, and Expression (PIE) face database. We also demonstrate the tolerance of these filters to noisy versions of images with illumination variations. 相似文献
79.
Sharon M Pradhan D Zacharia R Puri V 《Journal of nanoscience and nanotechnology》2005,5(12):2117-2120
Microwave absorption (8 GHz to 12 GHz) studies have been made with carbon nanomaterials for the first time. Carbon nanomaterials are synthesized by the pyrolysis of camphor. It is observed that film of carbon prepared under certain synthetic condition, can absorb microwave of either some specific wavelengths e.g., 9.5 GHz and 11.5 GHz or full range from 8-12 GHz to the extent of 20 dB depending upon their preparation condition. Carbon nanobeads seems to absorb the microwave in the range of 8-12 GHz. 相似文献
80.
A modification has been suggested to the reduction technique of Thomas Case [1], whereby it is easier to reduce less number-of-failure terms rather than more number-of-success terms. 相似文献