A general evaluation system for optimal selection performance of radar clutter model

The optimal selection of radar clutter model is the premise of target detection,tracking,recognition,and cognitive waveform design in clutter background.Clutter characterization models are usually derived by mathematical simplification or empirical data fitting.However,the lack of standard model labels is a challenge in the optimal selection process.To solve this problem,a general three-level evaluation system for the model selection performance is proposed,including model selection accuracy index based on simulation data,fit goodness indexs based on the optimally selected model,and evaluation index based on the supporting performance to its third-party.The three-level evaluation system can more comprehensively and accurately describe the selection performance of the radar clutter model in different ways,and can be popularized and applied to the evaluation of other similar characterization model selection.

Growth characteristics of spherical titanium oxide nanoparticles during the rapid gaseous detonation reaction

The nanosize grain growth characteristics of spherical single-crystal titanium oxide （TiO2） during the rapid gaseous detonation reaction are discussed. Based on the experimental conditions and the Chapman-Jouguet theory, the Kruis model was introduced to simulate the growth characteristics of spherical TiO2 nanoparticles obtained under high pressure, high temperature and by rapid reaction. The results show that the numerical analysis can satisfactorily predict the growth characteristics of spherical TiO2 nanoparticles with diameters of 15-300 nm at different affecting factors, such as concentration of particles, reaction temperature and time, which are in agreement with the obtained experimental results. We found that the increase of the gas-phase reaction temperature, time, and particle concentration affects the growth tendency of spherical nanocrystal TiO2, which provides effective theoretical support for the controllable synthesis of multi-scale nanoparticles.

Fine-scale hydrologic modeling for regional landscape applications:the California Basin Characterization Model development and performance

Introduction:Resource managers need spatially explicit models of hydrologic response to changes in key climatic drivers across variable landscape conditions.We demonstrate the utility of a Basin Characterization Model for California(CA-BCM)to integrate high-resolution data on physical watershed characteristics with historical or projected climate data to predict watershed-specific hydrologic responses.Methods:The CA-BCM applies a monthly regional water-balance model to simulate hydrologic responses to climate at the spatial resolution of a 270-m grid.The model has been calibrated using a total of 159 relatively unimpaired watersheds for the California region.Results:As a result of calibration,predicted basin discharge closely matches measured data for validation watersheds.The CA-BCM recharge and runoff estimates,combined with estimates of snowpack and timing of snowmelt,provide a basis for assessing variations in water availability.Another important output variable,climatic water deficit,integrates the combined effects of temperature and rainfall on site-specific soil moisture,a factor that plants may respond to more directly than air temperature and precipitation alone.Model outputs are calculated for each grid cell,allowing results to be summarized for a variety of planning units including hillslopes,watersheds,ecoregions,or political boundaries.Conclusions:The ability to confidently calculate hydrologic outputs at fine spatial scales provides a new suite of hydrologic predictor variables that can be used for a variety of purposes,such as projections of changes in water availability,environmental demand,or distribution of plants and habitats.Here we present the framework of the CA-BCM model for the California hydrologic region,a test of model performance on 159 watersheds,summary results for the region for the 1981–2010 time period,and changes since the 1951–1980 time period.

A Form Evaluation System and Its Data Structure for Brush-Written Chinese Characters

A form evaluation system for brush-written Chinese characters is developed.Calligraphic knowledge used in the system is represented in the form of ruleswith the help of a data structure proposed in this paper. Reflecting the spe-cific hierarchical relations among radicals and strokes of Chinese characters,the proposed data structure is based upon a character model that can generatebrush-written Chinese characters on a computer. Through evaluation experi-ments using the developed system, it is shown that representation of calligraphicknowledge and form evaluation of Chinese characters can be smoothly realizedif the data structure is utilized.

Characterizing drought in California:new drought indices and scenario-testing in support of resource management

Introduction:California’s recent drought(2012–2016)has implications throughout the state for natural resource management and adaptation planning and has generated many discussions about drought characterization and recovery.This study characterizes drought conditions with two indices describing deficits in natural water supply and increases in landscape stress developed on the basis of water balance modeling,at a fine spatial scale to assess the variation in conditions across the entire state,and provides an in-depth evaluation for the Russian River basin in northern California to address local resource management by developing extreme drought scenarios for consideration in planning and adaptation.Methods:We employed the USGS Basin Characterization Model to characterize drought on the basis of water supply(a measure of recharge plus runoff)and landscape stress(climatic water deficit).These were applied to the state and to the Russian River basin where antecedent soil moisture conditions were evaluated and extreme drought scenarios were developed and run through a water management and reservoir operations model to further explore impacts on water management.Results:Drought indices indicated that as of the end of water year 2016 when reservoirs were full,additional water supply and landscape replenishment of up to three average years of precipitation in some locations was needed to return to normal conditions.Antecedent soil conditions in the Russian River were determined to contribute to very different water supply results for different years and were necessary to understand to anticipate proper watershed response to climate.Extreme drought scenarios manifested very different kinds of drought and recovery and characterization helps to guide the management response to drought.Conclusions:These scenarios and indices illustrate how droughts differ with regard to water supply and landscape stress and how long warm droughts recover much more slowly than short very dry droughts due to the depletion of water in the soil and unsaturated zone that require filling before runoff can occur.Recognition of ongoing conditions and likelihood of recovery provides tools and information for a range of resource managers to cope with drought conditions.

Approximating interior bounded box of 3D character mesh model based on its skeleton and symmetry

Purpose – In the process of robot shell design, it is necessary to match the shape of the input 3D originalcharacter mesh model and robot endoskeleton, in order to make the input model fit for robot and avoidcollision. So, the purpose of this paper is to find an object of reference, which can be used for the process ofshape matching.Design/methodology/approach – In this work, the authors propose an interior bounded box (IBB)approach that derives from oriented bounding box (OBB). This kind of box is inside the closed mesh model.At the same time, it has maximum volume which is aligned with the object axis but is enclosed by all the meshvertices. Based on the IBB of input mesh model and the OBB of robot endoskeleton, the authors can completethe process of shape matching. In this paper, the authors use an evolutionary algorithm, covariance matrixadaptation evolution strategy (CMA-ES), to approximate the IBB based on skeleton and symmetry of inputcharacter mesh model.Findings – Based on the evolutionary algorithm CMA-ES, the optimal position and scale informationof IBB can be found. The authors can obtain satisfactory IBB result after this optimization process.The output IBB has maximum volume and is enveloped by the input character mesh model as well.Originality/value – To the best knowledge of the authors, the IBB is first proposed and used in the field ofrobot shell design. Taking advantage of the IBB, people can quickly obtain a shell model that fit for robot.At the same time, it can avoid collision between shell model and the robot endoskeleton.

On the Characterization and Fault Identification of Sequentially t-Diagnosable System Under PMC Model

Sequential diagnosis is a very useful strategy for system-level fault identification because of its lower cost of hardware.In this paper,the characterization of sequentially t-diagnosable system is given,and a tmiversal algorithm to seek faulty units in the system is developed.

圣人与圣徒——晚清时期亚伯拉罕形象的重写

引论哈佛大学韩南(Patrick Hanan,1927-2014)在《中国19世纪的传教士小说》一文中最先关注到,晚清来华传教士创作了众多讲述亚伯拉罕、约瑟、保罗等圣经人物生平故事的传记作品,如《摩西言行全传》(1836)、《约瑟言行全传》(1861)、《保罗言行》(1900)等,提出"圣经里的人物传记"这一概念。①在《1867年以前来华基督教传教士列传及著作目录》《中华基督教文字索引》《基督圣教出版各书书目汇纂》等资料中也有数量颇丰的此类"圣经人物传记"。②传教士们以《圣经》为主要依据、以传记为写作体式,用汉语所书写的圣经人物生平,塑造这些圣经人物的生平,试图塑造基督徒典范,向世人展现基督教图景。