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排序方式: 共有96条查询结果,搜索用时 46 毫秒
1.
An application of data envelopment analysis (DEA) for measuring and evaluating the operating efficiency of power plants in the Israeli Electric Corporation (IEC) is presented. Emphasis is placed on the process of screening the list of potential input and output factors and determining the most relevant ones. Special attention is given to the qualitative factor concerning air pollution, which is treated as a categorical variable. The incorporation of `standard data' is examined and the results are analyzed  相似文献   
2.
Roll G  Kaiser T  Schweiger G 《Applied optics》1998,37(12):2483-2492
In the framework of Mie theory the involved electromagnetic fields are expanded in an infinite series of multipoles. In numerical computations the summation has to be terminated after a finite number of terms (the expansion order N), which unavoidably produces errors. On the other hand, it is known that the contributions of terms of order l with x 相似文献   
3.
Kaiser T  Roll G  Schweiger G 《Applied optics》1996,35(30):5918-5924
Single optically levitated microparticles were investigated by Raman spectroscopy. The particles were composed of di-octyl-phthalate (DOP) and glycerol; these substances are not mixable and form a two-phase droplet. Measurements of the Raman spectrum confirm the formation of droplets containing both chemical species. The spectra show strong input and output structural resonances as expected. If the particle is in resonance, the field inside the particle is enhanced, and most of the inelastically scattered light is emitted from molecules close to the droplet rim. If the particle does not fulfill the resonance condition, the contribution of an individual molecule to the Raman scattering does not depend strongly on the radial position of this molecule. On this basis, the radial distribution of the two components inside the evaporating droplet was determined by time-dependent measurements of the Raman spectrum. Furthermore, elastic-light scattering and the evaporation characteristics of the particles were investigated.  相似文献   
4.
This study is the conclusion of an exploratory cross-cultural investigation of dream content and organization. Following our report in "Ego Modalities in the Manifest Dreams of Male and Female Chicanos," (Brenneis and Roll, 1975), this paper examines differences in the organization and content of dreams: (1) between Anglo men and women; (2) between Anglo and Chicano men and Anglo and Chicano women; and (3) between Anglos and Chicanos.  相似文献   
5.
This paper addresses the problem of identification of hybrid dynamical systems, by focusing the attention on hinging hyperplanes and Wiener piecewise affine autoregressive exogenous models, in which the regressor space is partitioned into polyhedra with affine submodels for each polyhedron. In particular, we provide algorithms based on mixed-integer linear or quadratic programming which are guaranteed to converge to a global optimum. For the special case where the estimation data only seldom switches between the different submodels, we also suggest a way of trading off between optimality and complexity by using a change detection approach.  相似文献   
6.
Nonlinear system identification via direct weight optimization   总被引:2,自引:0,他引:2  
A general framework for estimating nonlinear functions and systems is described and analyzed in this paper. Identification of a system is seen as estimation of a predictor function. The considered predictor function estimate at a particular point is defined to be affine in the observed outputs and the estimate is defined by the weights in this expression. For each given point, the maximal mean-square error (or an upper bound) of the function estimate over a class of possible true functions is minimized with respect to the weights, which is a convex optimization problem. This gives different types of algorithms depending on the chosen function class. It is shown how the classical linear least squares is obtained as a special case and how unknown-but-bounded disturbances can be handled.Most of the paper deals with the method applied to locally smooth predictor functions. It is shown how this leads to local estimators with a finite bandwidth, meaning that only observations in a neighborhood of the target point will be used in the estimate. The size of this neighborhood (the bandwidth) is automatically computed and reflects the noise level in the data and the smoothness priors.The approach is applied to a number of dynamical systems to illustrate its potential.  相似文献   
7.
Microscopic studies on non-pressed chips glued with polymeric diphenylmethane diisocyanate (MDI) and on some particleboard cross-sections showed that due to its good wetting properties this glue effects a good thin-layer spread on the surface of the wooden chips. Due to capillar action MDI completely penetrates cracks in the chips. Moreover, there was evidence that MDI is capable of penetrating the cell walls. Particleoboard cross-sections showed that most of the earlywood portion in chip mixes was evidently completely saturated with MDI.  相似文献   
8.
In this work, we present a fiber-delivered and fiber-detected, 3-DOF optical probe concept for measuring optical components to be used in conjunction with an optical coordinate measuring machine (OCMM). The optical probe uses a Michelson interferometer to produce carrier fringes and a high density fiber bundle to transmit interferograms that are recorded away from the probe head in a remote imaging system. We compare several different signal FFT processing techniques (parabolic interpolation, windowing, and zero padding) and a single-bin DFT technique to compute and enhance the resolution of the displacement, tip, and tilt of a moving mirror. We simulated varying signal-to-noise ratios and interference fringe contrast ranges to determine the algorithms’ sensitivity to those parameters and compare our simulated values to measured SNR and fringe values. Based on this work, it should be possible to use a carrier fringe algorithm for fiber probing applications if the interferogram can be transmitted through the fiber bundle with sufficient contrast (40%) and SNR (30 dB).  相似文献   
9.
Interpersonal intimacy is more difficult to achieve for American men than women. Research has shown that men disclose less, have fewer close friendships, and are viewed by their wives as low in intimacy. Among the barriers to intimacy among men, Tognoli (1980) suggested that homophobia is the most powerful. The present study tested this idea by asking men to disclose a personal secret to either a male confidant, a female confidante, or by writing the secret. It was expected that the presence of a male confidant would stimulate homophobic feelings and inhibit disclosure, while the other two conditions would result in more personal disclosure. A correlation between intimacy of disclosure and level of homophobia was also expected. Subjects were 75 heterosexual men, 31 to 50 years of age, randomly assigned to one of the three conditions. They also completed the Miller Social Intimacy Scale, the Jourard Self-Disclosure Questionnaire, the Index of Homophobia, and the Marlowe-Crowne Social Desirability Scale. Results showed that homophobia was inversely related to level of social intimacy. There was some indication that homophobia does relate to less intimate disclosure to other males. Thus this study found some support for the idea that homophobia is an obstacle to intimacy for men.  相似文献   
10.
OBJECTIVE: To determine whether screening for the presence of multiple antibody markers for IDDM is effective at identifying individuals with high risk for disease development. RESEARCH DESIGN AND METHODS: Antibodies to GAD and the tyrosine phosphatase-like protein 1A-2 were determined in sequential serum samples from 44 first-degree relatives of IDDM patients, identified as possessing islet cell antibody (ICA) and/or insulin autoantibody (IAA), who were followed prospectively for IDDM development, ICA, IAA, and antibodies to GAD and 1A-2 were also determined in 93 cases of new-onset nonfamilial IDDM. RESULTS: The presence of two or more antibodies in addition to ICA or IAA conferred high risk (61%) for development of IDDM within 5 years of entry into the study and identified 89% of those who have developed IDDM on current follow-up. None of the relatives positive for ICA or IAA alone, in the absence of other antibody markers, have developed IDDM. Antibodies to islet antigens could both appear and disappear in follow-up samples obtained after entry into the study. The majority (60%) of young (< 16 years), sporadic cases of IDDM had multiple antibodies to islet antigens, but this proportion was lower in older patients (37%). CONCLUSIONS: A screening strategy based on the analysis of antibodies to multiple islet antigens can predict IDDM at high sensitivity and specificity in families, and such a strategy may also be applicable to identify young individuals in the general population with high disease risk. Since appearance of antibodies to different antigens occurs sequentially rather than simultaneously, accurate assessment of diabetes risk based on the presence of multiple antibodies will require follow-up over a number of years after the first evidence of islet autoimmunity.  相似文献   
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