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91.
为了判断二维非对称受限编码的信道容量是否为正,提出了扫描方法.若满足限制(d1,k1,d2,k2)矩阵中的每个位置都可以通过已知的标志来决定并且被扫描,则限制(d1,k1,d2,k2)的信道容量为0.通过对特定二维受限编码信道容量的证明,验证了扫描方法比代数与组合方法更为有效.同时采用证明信道容量大于零常用的技术,找到满足(d1,k1,d2,k2)受限的两个m×n矩阵,若两矩阵在各种变形下都满足(d1,k1,d2,k2)限制,则信道容量Cd1,k1,d2,k2≥1/mn.这一方法对信道容量为正的区域进行扩展. 相似文献
92.
93.
We study the biaxial stress state conditions in landing gear fuse pins in the fuse groove. This biaxial state comprises a
combination of shear stresses which are usually the largest stresses in the fuse pin by design, and compressive stresses which
keep the half-section of the fuse pin in equilibrium. Conventional fatigue analysis techniques use an equivalent uniaxial
stress, based on the Mises stress of a pure-shear condition. The respective predicted fatigue damages are much higher than
those obtained from fuse pin cyclic tests. A new equivalent uniaxial fatigue stress model is proposed that includes the additional
compressive stress as a relief on the fatigue damage in the fuse groove, thereby explaining the observations from fuse pin
tests. The model is used in conventional uniaxial strain-life fatigue software (Goodrich Aerospace’s Fatigue Life V2) to predict
the fatigue damage on a landing gear fuse pin with a sample load spectrum. The results are then compared to the pure shear
model, and to a biaxial finite element fatigue analysis. As compared to the equivalent Mises model, the proposed model provides
less conservative estimation of the fuse pin fatigue life, the latter value being higher than that provided by the two-dimensional
finite element calculation.
__________
Translated from Problemy Prochnosti, No. 3, pp. 85–98, May–June, 2006. 相似文献
94.
A model is presented for determining porosity from a two-dimensional gas flow model. A device is described for determining
the porosity parameters. Experimental curves are given relating the porosity parameters to the thickness.
__________
Translated from Izmeritel’naya Tekhnika, No. 12, pp. 53–57, December, 2006. 相似文献
95.
96.
在三维计算机研究中,三维数据的输入是个复杂的问题。大量的数据处理也会带来大的障碍,使得计算机速度较慢。不仅如此,这对于计算机辅助设计,以及计算机艺术等领域更会带来很多的不便。故针对以上问题文中提出了基于二维图像来进行三维的转换,从而得到三维图像效果,将复杂问题变得简单化。采用了四叉树分割技术对计算机输入的二维图形进行三维转换,通过用这种方法找到二维图形的几何信息和拓扑信息进行几何造型,再将图形的结构信息输入给OpenGL,OpenGL对数据进行处理,通过投影变换将二维图形转换为三维图像。 相似文献
97.
98.
The way we look at problems affects how we study them and try to solve them. Different interventions become salient depending on whether we focus on individuals perceived to have the problem, on the social setting that fosters it, or on an interaction of the two. As psychologists, our training is conducive to thinking on the individual rather than on the system level. When we employ research strategies that personalize the political, we risk being complicit with conservative political agendas that avoid social change by focusing on individual dysfunction. Even community psychologists, despite dealing in system-level theories, too often transform these into individual-level research. I will use, as examples, poverty, drugs, homelessness, resilience, and empowerment. I argue that since our research can provide a justification for either changing or maintaining the status quo, it has ethical implications. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
99.
To date, few studies have sought to investigate the effects of child maltreatment and processes influencing maladaptation and resilience in Latino children. In the current investigation, multiple aspects of functioning, personal resources, and relationship features were examined in school-age maltreated and nonmaltreated Latino children. Maltreated Latino children were found to have fewer areas of resilient functioning. Ego-resiliency and ego-control, as personal resources, and the ability to form a positive relationship with an adult figure outside of the immediate family predicted resilience. However, certain aspects of interpersonal functioning were differentially related to resilience for maltreated and nonmaltreated Latino children. These findings have implications for understanding how resilience can be promoted in maltreated and nonmaltreated Latino children. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
100.
Ferris Patricia A.; Sinclair Christina; Kline Theresa J. 《Canadian Metallurgical Quarterly》2005,10(3):225
In a cross-sectional sample of 428 employees, the job demand-control-support and effort-reward imbalance job stress models were amalgamated and expanded to include modifiable risk factors and noncontrollable genetic factors related to cardiovascular disease (CVD) risk. With structural equation modeling, the constructs of lack of job resilience, lack of personal resilience, and job demand were used to examine how employer and employee factors related to psychosomatic strain and risk indicators of CVD. Negative perception of job demand predicted perception of lack of job resilience but not lack of personal resilience. Lack of job and personal resilience predicted strain. Women reported greater strain than men. CVD risk was predicted by strain, age, sex, and family history. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献