S.I.S.向量随机测度在弱拓扑及相容拓扑下的收敛性

本文主要研究ｓ．ｉ．ｓ．向量随机测度在弱拓扑及相容拓扑下的收敛性,给出了ｓ．ｉ．ｓ．向量随机测度在弱拓扑 容拓扑下的Ｖｉｔａｌｉ－Ｈａｌｍ－Ｓａｋｓ定理,作为应用,我们建立了Ｒ＾１－值有界可测函数关于Ｂａｎａｃｈ空间值ｓ．ｉ．ｓ．向量随机测度的随机积分的收敛定理,并得到了具ｔｙｐｅｐ的Ｂａｎａｃｈ空间中ｓ．ｉ．ｓ．向量随机测度的大数定律及中心极限定理。     

Hydrodynamic effects in low-grazing angle backscattering from theocean

Time series of returned power, Doppler spectra and range versus time intensity (RTI) images collected from low-grazing angle radar backscattering from the ocean present features which cannot be explained solely within the framework of resonant Bragg scattering. We propose that most of the observed characteristics are a consequence of the way in which waves evolve on the surface of the ocean. We have built a model consisting of a hydrodynamic module and a radar response module. The hydrodynamics module includes most of the physics thought to be relevant to the evolution of a wavefield (i.e., nonlinear interactions, wind, and wavebreaking). The radar module computes the backscattering as the accumulation of Bragg response from every tilted facet of the reconstructed surface, except for those locations where hydrodynamic conditions leading to wavebreaking are detected. Facets involved in wavebreaking are assumed to contribute to the backscattering in a quasi-specular polarization independent fashion. The hydrodynamics module is used to simulate the evolution of a nonlinear wave field, starting from essentially monochromatic conditions. The evolution reproduces known characteristics of these systems, including the generation of sideband instabilities and downshifting. The radar response module is then exercised on the resulting surface at various stages of development. Simulated RTIs at very low-grazing angles reproduce the observed polarimetric characteristics, as well as their behavior when the grazing angle is increased. Simulated Doppler spectra reproduce the peak separation phenomenon observed in field measurements at very low-grazing angles and also show a behavior similar to that shown by field data when the grazing angle is increased     

红外图像增强技术在TMS320DM642上的应用

针对红外图像普遍存在目标与背景对比度差、边缘模糊、信噪比低和灰度层次差等缺陷,提出了一种改进的直方图均衡红外图像增强算法。首先通过自适应地选择合适的灰度阈值,在图像直方图中将像素所占比例小于阈值的冗余灰度级完全压缩,并对大于阈值的有效灰度级进行基于一种非常合理的对数函数的拉伸变换;然后对拉伸后的灰度级进行常规的直方图均衡处理;最后在整个灰度范围内对经过均衡处理的图像灰度级进行等间距排列。为了满足算法的实时性,设计了一种以TMS320DM642高性能DSP芯片为核心处理器的红外图像增强系统平台。实验结果表明,采用该算法增强后的图像质量明显优于采用直方图均衡算法增强后的图像质量,图像的目标与背景的对比度和图像的清晰度都得到了提高,边缘细节也得到了保留;同时,采用该算法处理一帧320×256×8bits的红外图像仅仅用时16．73ms,完全满足实时图像处理的要求。     

红外透镜组中心偏差低温测试研究

红外透镜组的中心偏差是影响光学系统成像质量的重要因素之一。当红外探测器组件在低温环境中工作时,预先常温装配和测试的红外透镜组将产生装配精度失准现象。提出了一种在低温环境中测试红外透镜组中心偏差的方法。通过设计的低温测试系统解决了透镜组低温位置精度测量困难的问题。测试结果表明,该方法可以有效实现红外透镜组中心偏差的低温测试且测试误差优于2 μm。此研究对于高性能红外探测器组件研制具有一定的实际意义。     

A MODEL FOR ESTIMATING PREMIUMS TO REDUCE IRRIGATION ON FARMS

Abstract This paper aims to determine the minimum agri‐environmental premium per hectare that farmers should receive to reduce crop irrigation. To this end, the authors develop a mixed‐integer quadratic model using a new methodology based on traditional positive mathematical programming, which allows the inclusion in the model of crop variants that are not present in the baseline situation of the farms. What is shown is that the results obtained with this new methodology, using the cost average approach of calibration, are the same as those obtained with an empirical method, when there is no change of crop distribution after the changeover from irrigated to nonirrigated farms. The theoretical results are compared with those obtained using the calibration with exogenous elasticities and are illustrated numerically for a representative farm of an area around Spain's Tablas de Daimiel in which the use of groundwater for crop irrigation has led to the ongoing deterioration of wetlands that depend on the same source of water, endangering the region's environmental sustainability.     

Nature-Inspired Routing and Wavelength Assignment Algorithms for Optical Circuit-Switched Polymorphic Networks

Polymorphic optical networks simultaneously support several optical switching paradigms over a single physical network. In this way, they provide service differentiation at the optical layer by employing the most appropriate paradigm for each service. One type of such architecture is the optical circuit-switched polymorphic network (OCSPN), which combines optical circuit switching paradigms with different grades of dynamism. The performance of this network relies on the utilization of efficient routing and wavelength assignment (RWA) algorithms. In this article, we review the fundamentals of OCSPNs and present a set of efficient RWA algorithms based on ant colony optimization and genetic algorithms.     

Heart rate characteristics monitoring for neonatal sepsis

While heart rate variability has been measured in many clinical settings and has offered insights into how HR is controlled, rarely has it offered unique information that has led to changes in patient management. We review our experience in developing continuous HR characteristics monitoring to aid in the early diagnosis of sepsis in premature infants in the neonatal intensive care unit. A predictive algorithm, developed at one center and validated at another, has led to diagnosis and treatment of this subacute and potentially catastrophic illness prior to appearance of symptoms of severe illness.     

The Quantum and Classical Capacitance Limits of InSb and InAs Nanowire FETs

A comparison of nanowire FETs (NWFETs) of identical geometries but operating in two different regimes, namely, the quantum capacitance (QC) and classical capacitance (CC) regimes, is presented. n-type InSb and InAs NWFETs up to ~50 nm in diameter operate in the QC limit (QCL), and the corresponding p-type NWFETs operate in the CC limit. Drive currents at a fixed gate overdrive for the n- and p-type devices are found to be well matched. Nevertheless, the p-type devices have twice the delay times, half the intrinsic cutoff frequencies, twice the power-delay products, and four to five times the energy-delay products of the n-type devices, assuming transport is ballistic. Analytical expressions are derived for the QC, the current, the charge, the power-delay product, the energy-delay product, the gate delay time, and the cutoff frequency for a single-moded device operating in the QCL. The expressions for the power-delay product, energy-delay product, and the cutoff frequency are fundamental limits for such devices.