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81.
82.
When planning an SDH network, explicit structure, such as rings or a network hierarchy, is often imposed to allow for easier network protection and management. Decisions on node connectivity are also heavily dependent on available transmission capacity and network geography, as well as the demands placed on the SDH transport layer. The strictly imposed structure therefore makes it unlikely for unplanned properties to appear but here we describe how the BT SDH network exhibits emergent power-law properties in a range of metrics. These properties are similar to those previously found in the Internet, but the Internet in contrast is not globally planned, has adaptive elements such as dynamic routing and peering agreements, lacks explicit imposed structure, and is less coupled to transmission topologies.This paper shows that even with a wide range of restrictions and controls the BT SDH network topology follows power-laws and we offer possible sources for them, concentrating on the possible effect of adjacent network layers. The existence of these properties has wide implications in network modelling, as well as network scaling, growth, and robustness analysis. 相似文献
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84.
T. Jacob and K. Leonard (1986) reported that children of alcoholic fathers were comparable to children of depressed fathers in their psychosocial functioning. These results, however, were based on a relatively homogeneous sample. In the current study, previous results were extended by examining a sample of alcoholic fathers who were not screened for additional paternal psychiatric disorders or for major maternal psychopathology. Children in the unscreened and screened samples could not be distinguished in their functioning, and the majority of children of alcoholic fathers were functioning in the normal range of the Child Behavior Checklist. Given the heterogeneous adjustment in children of alcoholic fathers, the authors examined a range of factors that might protect against or exacerbate the risk associated with paternal alcoholism. Maternal depression and certain demographic characteristics were associated with poorer child functioning, particularly for male children. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
85.
Designing circuits with partial scan 总被引:1,自引:0,他引:1
Agrawal V.D. Kwang-Ting Cheng Johnson D.D. Sheng Lin T. 《Design & Test of Computers, IEEE》1988,5(2):8-15
In this scan design methodology, only selected faults are targeted for detection. These faults are those not detected by the designer's functional vectors. The test generator decides exactly which flip-flops should be scanned using one of two methods. In the first method, all possible tests are generated for each target fault, and the set of tests requiring the fewest flip-flops is selected. In the second method, only one test is generated for each fault, and the use of flip-flops is avoided as much as possible during test generation. Examples of actual VLSI circuits show a savings of at least a 40% in full-scan overhead 相似文献
86.
J. D. Russell J. Mumley M. Spring A. Kutz R. N. Johnson 《Journal of Automated Methods and Management in Chemistry》1991,13(3):115-117
To measure the content uniformity of conjugated cestrogens tablets,
the USP XXII monograph specifies a capillary gas chromatographic method. This involves separation of the trimethylsilyl derivatives of the various oestrogens found in a typical conjugated oestrogens tablet using a fused-silica 0V 225 bonded phase column. Hydrogen is used as the carrier gas with FID detection. A more rapid spectrophotofluorometric method of analysis has been developed in which the oestrogens are extracted from the dosage form into water, then transferred into organic solvent as the dicyclohexylamine complex. Fluorescence is developed by heating the solution of the complex in the presence of 70% sulphuric acid. The chemistry and detection are carried out using a segmented-flow analyser.The spectrophotofluorometric method is preferred as a routine control for content uniformity because considerable time is saved during sample preparation and analysis compared to gas chromatography. Coefficients of variation show that both methods produce
acceptable results. These results fall well within the USP XXII [1] monograph, limits and also well within the tighter limits imposed by the USP XXII, section 905. 相似文献
87.
A system modeling technique, Rainbow Nets, is used to evaluate the availability and mean-time-to-interrupt of the VAXcluster. These results are compared to the exact analytic results showing that reasonable accuracy is achieved through simulation. The complexity of the Rainbow Net implemented for the VAXcluster does not increase as the number of processors increases, but remains constant. This is unlike a Markov model which increases in size exponentially. The constancy is achieved by using tokens with identity attributes (items) that can have additional attributes associated with them (features) which can exist in multiple states. The time to perform the simulation increases, but this is a polynomial increase rather than exponential. With Rainbow Nets, there is no restriction on distributions used for transition firing times. This freedom allows real situations to be modeled more accurately by choosing the distribution which best fits the system performance. This eliminates the need to make the many simplifying assumptions that are typically required to keep analytic calculations from becoming intractable 相似文献
88.
Tobin David L.; Johnson Craig; Steinberg Stacey; Staats Marian; Dennis Amy Baker 《Canadian Metallurgical Quarterly》1991,100(1):14
Investigated a multifactorial approach to the assessment of bulimia nervosa by means of hierarchical factor analysis. 245 bulimia nervosa patients and 68 patients with either anorexia nervosa or eating disorders not otherwise specified were administered a self-report battery that was organized into 21 dimensions relevant to eating disorder patients. When dimensions from this battery were subjected to hierarchical factor analysis, support for bulimia nervosa as a unique diagnostic category was obtained. However, the emergence of 3 secondary factors and 6 primary factors suggests that bulimia nervosa can also be described more complexly. The emergence of a multifactorial model of bulimia nervosa that incorporates several existing unidimensional models suggests the potential for both divergent and complicated clinical presentation in bulimia nervosa patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
89.
Very high-order microring resonator filters for WDM applications 总被引:6,自引:0,他引:6
B.E. Little S.T. Chu P.P. Absil J.V. Hryniewicz F.G. Johnson F. Seiferth D. Gill V. Van O. King M. Trakalo 《Photonics Technology Letters, IEEE》2004,16(10):2263-2265
High-order microring resonators having from 1 to 11 coupled cavities are demonstrated. These filters exhibit low loss, flat tops, and out-of-band rejection ratios that can exceed 80 dB. They achieve performance that is suitable for commercial applications. 相似文献
90.