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1.
The problem of determining the maximum mean response level crossing rate of a linear system driven by a partially specified Gaussian load process has been considered. The partial specification of the load is given only in terms of its total average energy. The critical input power spectral (PSD) function, which maximizes the mean response level crossing rate, is obtained. The critical input PSD turns out to be highly narrow-banded which fails to capture the erratic nature of the excitation. Consequently, the trade-off curve between the maximum mean response level crossing rate and the maximum disorder in the input process, quantified in terms of its entropy rate, has been generated. The method of Pareto optimization is used to tackle the conflicting objectives of the simultaneous maximization of the mean response level crossing rate and the input entropy rate. The non-linear multi-objective optimization has been carried out using a recently developed multi-criteria genetic algorithm scheme. Illustrative example of determining the critical input of an axially vibrating rod, excited by a partially specified stationary Gaussian load process, has been considered.  相似文献   
2.
Pad effects on material-removal rate in chemical-mechanical planarization   总被引:1,自引:0,他引:1  
The role of a porous pad in controlling material-removal rate (MRR) during the chemical-mechanical planarization (CMP) process has been studied numerically. The numerical results are used to develop a phenomenological model that correlates the forces on each individual abrasive particle to the applied nominal pressure. The model provides a physical explanation for the experimentally observed domains of pressure-dependent MRR, where the pad deformation controls the load sharing between active-abrasive particles and direct pad-wafer contact. The predicted correlations between MRR and slurry characteristics, i.e., particle size and concentration, are in agreement with experimentally measured trends reported by Ouma1 and Izumitani.2  相似文献   
3.
Abhijit Datta 《Cities》1985,2(1):72-75
Early in 1983 the Indian Planning Commission appointed four Task Forces on Housing and Urban Development to review existing urban policies and to recommend appropriate action starting from the Seventh Plan (1985–1989). The Task Forces covered four areas of major concern: (1) urban planning, (2) urban finance, (3) urban organizations, and (4) urban shelter. They submitted their reports by the end of 1983, and taken together these constitute the most significant review of urban policy ever undertaken in India. 1 The Task Forces had distinguished urban experts, both officials and academics, as members, with a common Member-Secretary from the Planning Commission. The common theme in all four reports is a plea for a decentralized and equitable approach towards urban development in the country.  相似文献   
4.
Microsystem Technologies - A physics-based Quantum-Modified CLassical Drift–Diffusion (QMCLDD) non-linear mathematical model has been developed for design and characterisation of GaN/AlGaN...  相似文献   
5.
Carbon nitride films have been deposited by dielectric barrier discharge with a CH4/N2 gas mixture at different conditions. Fourier Transform Infrared (FTIR) spectroscopy, X-ray photo electron spectroscopy (XPS), Raman spectroscopy, Atomic force microscopy (AFM) and ellipsometry were used to systematically study chemical composition, bond structure and surface morphology of deposited films. Various bonds between carbon, nitrogen, hydrogen, and also oxygen were observed.  相似文献   
6.
In this Account, we explore the role constant curvature structures play in amphiphilic small molecule crystals and extended coordination solids. A constant curvature structure is one in which there is a surface or interface that has the same curvature throughout its surface. Simple examples of such structures contain spheres (micelles), columns, or layers. Yet another family are cubic as is found in the gyroid topology. For amphiphilic systems, there are two domains, one generally hydrophobic and the other hydrophilic. We find that the interfaces between these two domains in small molecule structures resemble those in larger scale systems and adopt topologies related to constant curvature structures. The hydrophobic-to-total volume ratio, a molecular parameter, can be used to predict which type of constant curvature structure is adopted. In the case of three coordinate extended solids, constant curvature plays a role both in the extended net topology and in the hydrophobic-to-hydrophilic interface.  相似文献   
7.
Model accuracy plays a key role in the performance of advanced, model predictive control algorithms. Model fidelity is usually affected by routine operating condition changes, which necessitate reidentification. From several theoretical and practical considerations, it is recommended that such re-identification be performed under closed-loop conditions. The direct approach for closed-loop identification, owing to its simplicity, is better suited for MPC. In order to yield unbiased and consistent parameter estimates, however, this approach requires the noise model to be sufficiently parameterized. Towards this objective, high order ARX models are the most suitable candidates from the viewpoint of ease of parameter estimation. For multivariable systems, however, the identification of high order ARX models would require longer experiments to be performed. This being undesirable from a practical viewpoint, there is a need for a parsimonious parameterization that would retain the benefits of high order ARX models. In this work, we propose to use generalized orthonormal basis filters (GOBFs) to achieve this parsimonous parameterization. Further, we propose an approach to obtain reduced order models by emphasizing important frequencies so as to suitably shape the bias. We also show that the choice of the GOBF parameterization has another important merit, viz. their ability to perform well even with minimal perturbation data or short experiment times. The efficacy of the proposed approach is demonstrated via simulations on the benchmark Shell Control Problem and a laboratory quadruple tank setup.  相似文献   
8.
Purpose: In (hemoglobin, Hb) HbEβ‐thalassemia, HbE (β‐26 Glu→Lys) interacts with β‐thalassemia to produce clinical manifestation of varying severity. This is the first proteomic effort to study changes in protein levels of erythrocytes isolated from HbEβ‐thalassemic patients compared to normal. Experimental design: We have used 2‐DE and MALDI‐MS/MS‐based techniques to investigate the differential proteome profiling of membrane and Hb‐depleted fraction of cytosolic proteins of erythrocytes isolated from the peripheral blood samples of HbEβ‐thalassemia patients and normal volunteers. Results: Our study showed that redox regulators such as peroxiredoxin 2, Cu‐Zn superoxide dismutase and thioredoxin and chaperones such as α‐hemoglobin stabilizing protein and HSP‐70 were upregulated in HbEβ‐thalassemia. We have also observed larger amounts of membrane associated globin chains and indications of disruption of spectrin‐based junctional complex in the membrane skeleton of HbEβ‐thalassemic erythrocytes upon detection of low molecular weight fragments of β‐spectrin and decrease in β‐actin and dematin content. Conclusion and clinical relevance: We have observed interesting changes in the proteomic levels of redox regulators and chaperons in the thalassemic hemolysates and have observed strong correlation or association of the extent of such proteomic changes with HbE levels. This could be important in understanding the role of HbE in disease progression and pathophysiology.  相似文献   
9.
The temporal scale effect of loading data on nitrate-nitrogen load computation was examined using outputs of watershed modeling tool Hydrologic Simulation Program-FORTRAN (HSPF) for the Amite River in Louisiana, USA. The daily nitrate-nitrogen concentrations simulated using the HSPF were employed first to obtain daily, weekly, bi-weekly, and monthly average data and then to develop load duration curves for the data with four different temporal scales. The duration curves exhibited high variability in the load estimated using daily data as compared with those based on bi-weekly and monthly data. According to daily data, the nitrate-nitrogen load in the winter was found to be 2,780 kg. The nitrate-nitrogen load decreased with increasing temporal (daily, weekly, bi-weekly, and monthly) scale (commonly used in water quality monitoring) of the data. The coefficient of variation, used to quantify the effect of temporal scale on the load, was found to be linearly and inversely correlated with the logarithm of the time scale. Based on the finding, empirical equations were proposed to extrapolate near real-time data for flow and nitrate-nitrogen, greatly simplifying nutrient monitoring and reducing the cost involved in water quality monitoring.  相似文献   
10.
ExpressCard模块是由PCMCIA推出的一种更薄、更快、更轻的抽屉式插卡,用以取代现有的PC卡和CardBus模块,主要用于笔记本计算机后继市场中的功能性升级和扩展.同样,ExpressCard模块最初旨在服务于笔记本计算机后继市场(图1a).  相似文献   
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