PERFORMANCE ANALYSIS OF TWO-WAY AMPLIFY-AND-FORWARD RELAYING SYSTEM WITH MULTIPLE INTERFERERS AT THE RELAY

In this paper,we investigate the performance of the two-way Amplify-and-Forward(AF) relaying systems in an interference-limited Rayleigh fading environment.More specifically,assuming the presence of Rayleigh faded multiple interferers at the AF relay and noisy sources,an approximate closed-form expression for the Overall Outage Probability(OOP) and an integral expression for the average Symbol Error Probability(SEP) are derived.The analysis results are verified through com-parison with the Monte Carlo simulation results.

An Investigation of the Illumination Effects on Pilling Evaluation

In this paper, a study of the illumination effects on the objective evaluation of fabric pilling was conducted for the purpose of optimization and validation of image analysis methods. A simple theoretical reflectance model of fabric surface with pills was presented in the consideration of its pill height, its pill width, and the incidence angle of illumination. Our investigation shows that the bi-directional illumination can achieve a better imaging result than one-side illumination, and it is reasonable to evaluate fabric pilling based on image analysis and template matching method.

Structured illumination microscopy based on principal component analysis

Structured illumination microscopy(SIM)is one of the powerful super-resolution modalities in bioscience with the advantages of full-field imaging and high photon efficiency.However,artifact-free super-resolution image reconstruction requires precise knowledge about the illumination parameters.The sample-and environment-dependent on-the-fly experimental parameters need to be retrieved a posteriori from the acquired data,posing a major challenge for real-time,long-term live-cell imaging,where low photobleaching,phototoxicity,and light dose are a must.In this work,we present an efficient and robust SIM algorithm based on principal component analysis(PCA-SIM).PCA-SIM is based on the observation that the ideal phasor matrix of a SIM pattern is of rank one,leading to the low complexity,precise identification of noninteger pixel wave vector and pattern phase while rejecting components that are unrelated to the parameter estimation.We demonstrate that PCA-SIM achieves non-iteratively fast,accurate(below 0.01-pixel wave vector and 0.1%of 2relative phase under typical noise level),and robust parameter estimation at low SNRs,which allows real-time super-resolution imaging of live cells in complicated experimental scenarios where other state-of-the-art methods inevitably fail.In particular,we provide the open-source MATLAB toolbox of our PCA-SIM algorithm and associated datasets.The combination of iteration-free reconstruction,robustness to noise,and limited computational complexity makes PCA-SIM a promising method for high-speed,long-term,artifact-free super-resolution imaging of live cells.

A Local Binary Pattern-Based Method for Color and Multicomponent Texture Analysis

Local Binary Patterns (LBPs) have been highly used in texture classification for their robustness, their ease of implementation and their low computational cost. Initially designed to deal with gray level images, several methods based on them in the literature have been proposed for images having more than one spectral band. To achieve it, whether assumption using color information or combining spectral band two by two was done. Those methods use micro structures as texture features. In this paper, our goal was to design texture features which are relevant to color and multicomponent texture analysis without any assumption. Based on methods designed for gray scale images, we find the combination of micro and macro structures efficient for multispectral texture analysis. The experimentations were carried out on color images from Outex databases and multicomponent images from red blood cells captured using a multispectral microscope equipped with 13 LEDs ranging from 375 nm to 940 nm. In all achieved experimentations, our proposal presents the best classification scores compared to common multicomponent LBP methods. 99.81%, 100.00%, 99.07% and 97.67% are maximum scores obtained with our strategy respectively applied to images subject to rotation, blur, illumination variation and the multicomponent ones.

A bibliometric analysis of research on nursing models in countries other than China

Objectives＂ To deepen our understanding of the status quo and to identify the hot topics and develop- mental trends of research on nursing models in countries other than China in the most recent decade. Methods： The study subjects were the publications retrieved from the PubMed database using the MeSH terms of ＂Models, Nursing＂. Bibliographic item co-occurrence mining system （BICOMS） software was used for conventional bibliometric analysis of publications during two time periods, 2005-2009 and 2010-2014. The number of published journal articles, journal distribution, authors of publications, country of origin of journals, and language of publications were analyzed to establish a high-frequency keyword profile and co-occurrence matrix. Graphical clustering toolkit （gCLUTO） software was applied for two-way clustering analysis and visualized analysis. Results： A total of 1472 journal articles with a key theme of nursing models were retrieved for final analysis, including 771 published during 2005-2009 and 701 during 2010-2014. The bibliometric analysis revealed that publications other than China concerning nursing models were mostly concentrated in the United States and the United Kingdom and that the number of relevant publications has been continuously decreasing. The two-way clustering analysis showed that there were mainly four types of research themes in the relevant publications in countries other than China during 2005-2009, i.e., nursing education and theoretical research, clinical nursing and psychological care, nursing administration, and models of nursing education, whereas there were five types during 2010-2014, i.e., nursing theories and clinical nursing practice, nursing administration models and assessments of nurses＇ knowledge and skills, community nursing administration models, nursing human resource management, and nursing education models and approaches. Conclusions： Research on nursing models in countries other than China is relatively mature and stable with a broader view, but it has shown a declining trend in recent years. It emphasizes both theory and practice, with research content tending to be structured into four modules, i.e., nursing education, administration, clinical practice, and theoretical research. Community nursing models may become a key research direction in the international research on nursing models in the future.

基于照明分析和偏移成像实验的主动震源探测系统设计——以朱溪矿区为例

为了探讨利用绿色环保的非炸药主动震源技术勘查我国西部、南部复杂山地深部矿产资源的可行性,并提出可行的探测方案,以景德镇朱溪矿区为例开展了基于照明分析和叠前深度域偏移成像实验的主动源地震探测系统设计研究。在现场踏勘和充分收集地质、钻探成果的基础上,根据矿区42号线钻孔联合剖面和相应的岩石物性测量成果建立了地球物理模型。由于后续地震数据采集工作主要利用单分量纵波检波器开展,在地震波的数值模拟方面选用了粘声波方程;工区崎岖地表所带来的不规则自由表面问题则通过Acoustic-Elastic boundary Approach(AEA)方案解决。进行了震源-检波器组双向照明分析,以及高信噪比(20db)和低信噪比(6db)两种情况下的地震波叠前深度域逆时偏移成像实验。研究结果表明,通过合理布设较为密集的主动震源激发-接收系统,采用环境友好的非炸药主动震源技术可以查明目标区地下主要地层,和断层、逆掩推覆体等主要控矿构造的空间展布。后续实际的地震数据采集工作在本次研究的基础上开展,取得的朱溪矿区第一手非炸药震源绿色勘查成像剖面证明了本次研究所提出的探测方案是可行的和有效的。通过不断完善技术体系,非炸药主动震源技术有望为我国深部矿产资源勘探、隐伏断裂勘查、城市地下空间探测等研究领域提供一种环保、高效的技术手段。本次研究所采用的基于照明分析和偏移成像实验的复杂山地主动震源探测系统设计、论证方法值得进一步研究和推广。

Assessment of plant diversity of endemic species of the Saharo-Arabian region in Egypt

Savanna, semi-deserts, and hot deserts characterize the Saharo-Arabian region, which includes Morocco, Mauretania, Algeria, Tunisia, Libya, Egypt, Palestine, Kuwait, Saudi Arabia, Qatar, Bahrain, the United Arab Emirates, Oman, Yemen, southern Jordan, Syria, Iraq, Iran, Afghanistan, Pakistan, and northern India. Its neighboring regions, the Sudano-Zambezian region belonging to the Paleotropical Kingdom and the Mediterranean and Irano-Turanian regions included in the Holarctic Kingdom, share a large portion of their flora with the Saharo-Arabian region. Despite the widespread acknowledgment of the region's global importance for plant diversity, an up to date list of the Saharo-Arabian endemics is still unavailable. The available data are frequently insufficient or out of date at both the whole global and the national scales. Therefore, the present study aims at screening and verifying the Saharo-Arabian endemic plants and determining the phytogeographical distribution of these taxa in the Egyptian flora. Hence, a preliminary list of 429 Saharo-Arabian endemic plants in Egypt was compiled from the available literature. Indeed, by excluding the species that were recorded in any countries or regions outside the Saharo-Arabian region based on different literature, database reviews, and websites, the present study has reduced this number to 126 taxa belonging to 87 genera and 37 families. Regarding the national geographic distribution, South Sinai is the richest region with 83 endemic species compared with other eight phytogeographic regions in Egypt, followed by the Isthmic Desert(the middle of Sinai Peninsula, 53 taxa). Sahara regional subzone(SS1) distributes all the 126 endemic species, Arabian regional subzone(SS2) owns 79 taxa, and Nubo-Sindian subzone(SS3) distributes only 14 endemics. Seven groups were recognized at the fourth level of classification as a result of the application of the two-way indicator species analysis(TWINSPAN) to the Saharo-Arabian endemic species in Egypt, i.e., Ⅰ Asphodelus refractus group, Ⅱ Agathophora alopecuroides var. papillosa group, Ⅲ Anvillea garcinii group, Ⅳ Reseda muricata group, V Agathophora alopecuroides var. alopecuroides group, Ⅵ Scrophularia deserti group, and Ⅶ Astragalus schimperi group. It's crucial to clearly define the Saharo-Arabian endemics and illustrate an updated verified database of these taxa for a given territory for providing future management plans that support the conservation and sustainable use of these valuable species under current thought-provoking devastating impacts of rapid anthropogenic and climate change in this region.

大功率LED灯的光学仿真设计

大功率LED灯具作为一种新型的照明产品,光学仿真设计是LED灯具设计过程中关键的环节之一,它能够模拟LED灯具的光学性能、发光特性、照度分布等重要参数,为灯具的优化设计和生产提供后期的指导和检验,有助于提高LED灯具的性能和质量,并促进其市场竞争力的提升。因此,研究目的在于探究大功率LED灯的光学仿真设计,为其质量提升、技术提升和应用推广提供重要支持。首先对大功率LED灯的光学特性进行了理论分析和计算,结合实际生产和应用需求,建立了一套基于光学仿真软件的LED灯光学仿真设计方案。

The Average Achievable Rate of Multi-Antenna Two-Way Relay Networks with Interference Alignment

The large system analysis(LSA)has recently been shown to be a very useful tool for computing the average achievable rate.In this paper,we use LSA to derive the users’average achievable rate of multi-antenna two-way relay networks with interference alignment(IA),and we then derive the rate expressions under both equal power allocation and optimal power allocation.It is shown that the obtained closed-form rate expressions are functions of the average signal-to-noise ratio(SNR)for each data stream.Extensive simulation studies show that the average achievable rate expressions derived through LSA provide accurate estimates of the average achievable rate for two-way relay networks with interference alignment.

Technology of shipboard two-way microwave time synchronization

For the high precision time synchronization demand of ships, advantages and disadvantages of the present time transfer methods are analyzed, the two-way microwave time transfer （TWMTT） method is adopted to resolve the time synchronization problem in the Naval Ship Formation. After expounding the principle and system composition of TWMTT method, the various factors influencing the synchronous precision are analyzed, such as time-interval measurement error, TWMTT equipment delay error, signal propagation error in air, and signal delay error caused by shipping. To improve the time synchronization precision, all the error sources above are deduced with mathematical measures to definite the critical one, and the signal processing measures such as Pseudo code spread spectrum time comparison signal generation technology, FFT fast acquisition technology and precise tracking technology are used into the modem which is the core equipment of the TWMTT. And, calibration method of TWMTT equipment delay are developed. Through theoretical a- nalysis and simulation verification, the precision of shipboard two-way microwave time synchroniza- tion can reach 1 ns.

Conversion of One- to Two-Way Streets in Birmingham, Alabama

This paper summarizes the approach, findings and evaluation methodology for a study that investigated the feasibility and potential impacts of street conversion options on traffic operations in downtown Birmingham, Alabama. Of particular interest were issues related to conversion of grid systems from one-way to two-way operations. Recommendations on the most promising design and control configurations for implementation are also provided. A literature review was performed that threw light on the issues and challenges associated with implementation of street conversions, and the available best practices. A comprehensive traffic impact analysis that ensued employed the SYNCHRO computer simulation model to represent current and future operations so as to assess the implications of two-way conversions at and around the test sites. Detailed realistic two-way operations scenarios were developed that considered geometric and right-of-way restrictions, the location of land uses that generate and/or attract vehicular and pedestrian traffic, connectivity with the street grid, and accessibility to nearby freeway facilities, as well as practical concerns.

Numerical Simulation Study of Vibration Characteristics of Cantilever Traffic Signal Support Structure under Wind Environment

Computational fluid dynamics(CFD)and the finite element method(FEM)are used to investigate the wind-driven dynamic response of cantilever traffic signal support structures as a whole.By building a finite element model with the same scale as the actual structure and performing modal analysis,a preliminary understanding of the dynamic properties of the structure is obtained.Based on the two-way fluid-structure coupling calculation method,the wind vibration response of the structure under different incoming flow conditions is calculated,and the vibration characteristics of the structure are analyzed through the displacement time course data of the structure in the crosswind direction and along-wind direction.The results show that the maximum response of the structure increases gradually with the increase of wind speed under 90°wind direction angle,showing a vibration dispersion state,and the vibration response characteristics are following the vibration phenomenon of galloping;under 270°wind direction angle,the maximum displacement response of the structure occurs at the lower wind speed of 5 and 6m/s,and the vibration generated by the structure is vortex vibration at this time;the displacement response of the structure in along-wind direction increaseswith the increase of wind speed.The along-wind displacement response of the structure will increase with increasing wind speed,and the effective wind area and shape characteristics of the structurewill also affect the vibration response of the structure.

Hydro-elastic computational analysis of a marine propeller using two-way fluid structure interaction

Marine propellers have complex geometry and their performance is determined by costly and time consuming open water experiments.Use of numerical techniques helps researchers in effective design of propellers.Several approaches are used that predicted either hydrodynamic and acoustic response or structural response.Two-way fluid-structure interaction(FSI)analysis is a very useful approach providing all three responses which helps in the design,analysis and optimization of a propeller.The objective of this paper is to predict the hydro-elastic response of a propeller using two-way FSI on a 0.2m diameter,DTMB-4119 propeller using ANSYS software.Two-way FSI analysis is carried out using system coupling approach that transfers the data between the structural and fluid solvers.The turbulence effects are captured using the large-eddy simulation(LES)model and the Ffowcs Williams Hawkings(FWH)acoustic model is used for evaluating the sound pressure level(SPL)generated by propeller.Analysis is extended to evaluate the hydro-elastic and acoustic response of the propeller after validating the hydrodynamic performance with the experimental result in the literature.The results from Two-way FSI analysis are in close agreement when compared with the one-way FSI analysis.Two-way FSI can accommodate the peak value of stress and deformation developed during the initial part of the transient solution which is important in the design of propeller.This study reveals that metallic(NAB)propeller can be replaced by a composite propeller.The acoustic response from two-way FSI analysis will be more realistic due to the consideration of hydro-elastic effect of propeller.

基于DIALuX的体育馆照明设计案例分析

利用DIALux仿真软件搭建体育馆模型,从灯具配光曲线、灯具布置、马道位置等方面考虑,在满足规范要求照明质量和检测标准的前提下,对实际工程中体育馆篮球场进行照明设计,并根据仿真结果验证设计质量,完整展示体育馆照明设计过程。

单次曝光的结构光显微三维测量方法

光切片结构光显微的三维测量速度一直是该技术应用方面的重要关注点。基于光切片的三维测量方法需要在同一个轴向位置进行至少两次曝光,才能获得该位置的光切片信息。文章提出一种单次曝光的结构光显微三维测量方法,在轴向扫描的每个位置只需拍摄一幅结构光显微图像,相邻轴向位置的条纹存在一定的相移;然后分析每个像素对应的轴向灰度曲线,计算轴向调制度并定位峰值;最后进行标定和换算,便可得到样品的三维重建结果。实验证明,所提方法可以得到与光切片方法相当的测量精度,测量效率和图像处理效率都比光切片法有很大提升。

插值法在热辐射类治疗设备紫外辐照度检测中的应用

随着热辐射类治疗设备在临床上的广泛应用,相应的行业标准也在不断完善。针对YY 0306-2018《热辐射类治疗设备安全专用要求》标准中有效紫外辐照度限值判定的问题,该研究运用不同插值法对紫外辐照度进行量值计算,得到更优的光化学紫外危害加权函数计算方法,并将该算法应用于热辐射类治疗设备紫外辐照度检测分析软件中,利用该分析软件可以达到增强检验方法的严谨性和普适性,提升检验效率及保证检验质量的目的。

正反向照明分析在高陡构造地震采集中的应用

川东南地区的构造复杂区地震资料品质较差,下伏地层成像不理想,为了解决这一难题,我们依据以往资料构建了二维地质模型,在高陡构造区域进行模拟激发接收,开展波动方程照明,进行最大偏移距和激发位置范围优化。本文通过正向照明分析技术,论证最佳的最大炮检距长度,利用反向照明分析技术确定特定目标体的优势激发点位,优选激发范围。通过调整地质目标体的照明能量属性,分析照明效果,进一步优化了高陡构造区野外采集观测系统,改善了地震采集资料品质,提高了地质勘探效果。

矿井低照度条件下广角摄像仪性能测试方法研究

研究矿井低照度条件下广角摄像仪的性能指标测试方法,对比分析常见的测试方法,以提高矿井内视频监控系统的可靠性和安全性。介绍了低照度环境下广角摄像仪的应用背景、发展趋势和相关标准要求,并且介绍了判断摄像仪成像质量的核心指标MTF调制传递函数(Modulation Transfer Function),以及常用测试图卡的原理和应用。然后,对比分析了两种测试方法,包括广角测试灯箱+SFRreg测试卡+图像质量分析软件和光学暗室+预畸变测试卡+SFRreg测试卡+图像质量分析软件测试方法。最后,结合实际应用,对广角摄像仪在矿井低照度环境下的测试方法进行了总结和评价,并提出了进一步研究的方向。为矿井内视频监控系统的测试提供理论和实践指导。

Spatial and environmental effects on plant communities in the Yellow River Delta, Eastern China

Types and structure of plant communities in the Yellow River Delta were investigated by using detrended canonical correspondence analyses （DCCAs） and a two-way indicator species analysis （TWINSPAN）. The distribution pattern and influential factors of the plant communities were also analyzed by testing elevation, slope, soil characteristics, longitude and latitude of 134 vegetation samples collected by representative plot sampling methods. Results showed that all the 134 vegetation samples could be divided into seven vegetation groups, separately dominated by Robinia pseucdoacacia, Imperata cylindrical, Miscanthus saccharifleus, Suaeda salsa, Aeluropus sinensis, Phragmites australis and Tamarix chinensis. The vegetation distribution pattern was mainly related to elevation, ground water depth and soil characteristics such as salinity and soluble potassium. Among the factors affecting distribution pattern of the plant communities, the species matrix explained by non-spatial environmental variation accounts for 45.2% of total variation. Spatial variation and spatial-structured environmental variation explain 11.8%, and 2.2%, respectively. Remained 40.8% of undetermined variation is attributed to biological and stochastic factors.

道路照明中视觉反应时间与光源光谱之间的关系研究

研究了道路照明光源的相对视觉反应时间、相对发光效率和乘法系数之间的关系 ,结果表明 ,它们均是光源光谱功率分布对视觉影响的不同表示形式。最后 ,为了便于在道路照明中运用 ,还给出了由相对发光效率计算相对视觉反应时间和乘法系数的表达式。