窄带干扰下MIMO系统的特征域传输方案

该文提出一种特征域的传输方案(ETS),用以提高窄带干扰下MIMO系统的容量。首先,发射端在特征域产生N路发射信息,然后根据窄带干扰信号的统计特征,通过预编码将发射信息从特征域变换至时域进行传输。在接收端,时域的接收信号再次被变换为N路特征域信号。据此,期望信道被划分为N路并行子信道,根据各子信道的干扰分布采用相对应的传输方案,以最大化干扰场景下信道的利用率。由计算机仿真可得,当系统容量为15 bit/(s·Hz)时,该文所提特征域传输方案相对于传统干扰抑制算法在2×2 MIMO系统中取得了约10 d B的性能增益。

2004北京国际通信展城域MSTP方案一瞥

思科:把多业务网络从城网核心扩展到客户端 思科是业界最早提出多业务传输平台(MSTP)概念并开发出相应产品的厂商之一,目前思科拥有完整的光网多业务边缘到核心的传输(COMET系列产品,包括ONS 15454 SONETSDH多服务供应平台(MSPP)、带集成DWDM功能的ONS 15454SONET/SDH MSPP、ONS 15600多服务交换平台(MSSP),以及ONS 15302和ONS 15305第二代多业务接入/汇聚平台等.可以将多业务网络从城域网核心一直扩展到客户端,从而让电信运营商可以更经济有效地支持数据业务和现有的语音业务.

Bayesian prestack seismic inversion with a self-adaptive Huber-Markov random-field edge protection scheme

Seismic inversion is a highly ill-posed problem, due to many factors such as the limited seismic frequency bandwidth and inappropriate forward modeling. To obtain a unique solution, some smoothing constraints, e.g., the Tikhonov regularization are usually applied. The Tikhonov method can maintain a global smooth solution, but cause a fuzzy structure edge. In this paper we use Huber-Markov random-field edge protection method in the procedure of inverting three parameters, P-velocity, S-velocity and density. The method can avoid blurring the structure edge and resist noise. For the parameter to be inverted, the Huber- Markov random-field constructs a neighborhood system, which further acts as the vertical and lateral constraints. We use a quadratic Huber edge penalty function within the layer to suppress noise and a linear one on the edges to avoid a fuzzy result. The effectiveness of our method is proved by inverting the synthetic data without and with noises. The relationship between the adopted constraints and the inversion results is analyzed as well.

电子政务MPLS VPN网的MD组播及应用

结合组播业务在电子政务中的应用,通过对电子政务MPLS VPN组网和VPN组播MD方案进行研究,提出了一种可普遍应用于电子政务MPLS VPN网络的组播解决方案,MD组播方案配置简单,对原有网络改造小,可控性高,扩展性强,在电子政务MPLS VPN网络中推广价值极大。

SM4抗差分功耗分析轻量级门限实现

针对SM4门限实现(TI)面积大、随机数消耗多的问题,提出一种SM4门限实现的改进方案。在满足门限实现理论的情况下,对S盒非线性求逆进行了无随机共享,并引入面向域的乘法掩码方案,将S盒随机数消耗减少至12 bit;基于流水线思想,设计了新的8 bit数据位宽的SM4串行体系结构,复用门限S盒,并优化SM4线性函数,使SM4门限实现面积更加紧凑,仅6513 GE,相较于128 bit数据位宽的SM4门限实现方案,所提方案的面积减小了63.7%以上,并且更好地权衡了速度和面积。经侧信道检验,所提出的改进方案具备抗一阶差分功耗分析(DPA)能力。

CWRF-based ensemble simulation of tropical cyclone activity near China and its sensitivity to the model physical parameterization schemes

To evaluate the downscaling ability with respect to tropical cyclones(TCs)near China and its sensitivity to the model physics representation,the authors performed a multi-physics ensemble simulation with the regional Climate-Weather Research and Forecasting(CWRF)model at a 30 km resolution driven by ERA-Interim reanalysis data.The ensemble consisted of 28 integrations during 1979-2016 with varying CWRF physics configurations.Both CWRF and ERA-Interim can generally capture the seasonal cycle and interannual variation of the TC number near China,but evidently underestimate them.The CWRF downscaling and its multi-physics ensemble can notably reduce the underestimation and significantly improve the simulation of the TC occurrences.The skill enhancement is especially large in terms of the interannual variation,which is most sensitive to the cumulus scheme,followed by the boundary layer,surface and radiation schemes,but weakly sensitive to the cloud and microphysics schemes.Generally,the Noah surface scheme,CAML(CAM radiation scheme as implemented by Liang together with the diagnostic cloud cover scheme of Xu and Randall(1996))radiation scheme,prognostic cloud scheme,and Thompson microphysics scheme stand out for their better performance in simulating the interannual variation of TC number.However,the Emanuel cumulus and MYNN boundary layer schemes produce severe interannual biases.Our study provides a valuable reference for CWRF application to improve the understanding and prediction of TC activity.

Some Secret Sharing Schemes Based on the Finite Fields

A （t, n）--secret sharing scheme is a method of distribution of information among n participants such that t 〉 1 can reconstruct the secret but （t - 1） cannot. We explore some （k, n）--secret sharing schemes based on the finite fields.

IEEE 1588精密时钟同步协议测试技术

介绍了IEEE 1588PTP精密时钟同步协议的原理、同步流程、测试方法、测试流程和测试结果,以及IXIA全面的城域以太网测试方案。

Application of different clustering approaches to hydroclimatological catchment regionalization in mountainous regions, a case study in Utah State

With respect to the different hydrological responses of catchments, even the adjacent ones, in mountainous regions, there are a great number of motivations for classifying them into homogeneous clusters. These motivations include prediction in ungauged basins(PUB), model parameterization, understanding the potential impact of environmental changes, transferring information from gauged catchments to the ungauged ones. The present study investigated the similarity of catchments through the hydro-climatological pure time-series of a 14-year period from 2001 to 2015. Data sets encompass more than 13,000 month-station streamflow, rainfall, and temperature data obtained from 27 catchments in Utah State as one of the eight mountainous states of the USA. The identification, analysis, and interpretation of homogeneous catchments were investigated by applying the four approaches ofclustering, K-means, Ward, and SOM(Self-Organized Map) and a newly proposed Wavelet-Entropy-based(WE-SOM) clustering method. By using two clustering evaluation criteria, 3, 5, and 6 clusters were determined as the best numbers of clusters, depending on the method employed, where each cluster represents different hydro-climatological behaviors. Despite the absence of geographic characteristics in input data matrix, the results indicated a regionalization in agreement with topographic characteristics. Considering the dependency of the hydrological behavior of catchments on the physiographic field aspects and characteristics, WE-SOM method demonstrated a more acceptable performance, compared to the other three conventional clustering methods, by providing more clusters. WE-SOM appears to be a promising approach in catchment clustering. It preserves the topological structure of data which can, as a result, be proofed in a greater number of clusters by dividing data into higher numbers of distinct clusters withsimilar altitudes of catchments in each cluster. The results showed the aptitude of wavelets to quantify the time-based variability of temperature, rainfall and streamflow, in the way contributing to the regionalization of diverse catchments.

Dynamic Cell Range Expansion-based Interference Coordination Scheme in Next Generation Wireless Networks

Deploying Picocell Base Station(PBS) throughout a Macrocell is a promising solution for capacity improvement in the next generation wireless networks.However,the strong received power from Macrocell Base Station(MBS) makes the areas of Picocell narrow and limits the gain of cell splitting.In this paper,we firstly propose a Dynamic Cell Range Expansion(DCRE) strategy.By expanding the coverage of the cell,we aim to balance the network load between MBS and PBS.Then,we present a cooperative Resource block and Power Allocation Scheme(coRPAS)based on DCRE.The objective of coRPAS is to decrease interference caused by MBS and Macrocell User Equipments,by which we can expand regions of Picocell User Equipments.Simulation results demonstrate the superiority of our method through comparing with other existing methods.

A novel cell search scheme for OFDM cellular systems

A novel cell search scheme for OFDM cellular systems is proposed. It is based on one OFDM symbol with several identical slots as preamble, the time domain repetition structure of which can be utilized to accomplish OFDM timing/frequency synchronization. The cell ID is comprised of two parts: a sub-carrier mask index g and a sequence index x. Each sub-carrier mask activates or deactivates some of the sub-carriers, after which a differentially coded sequence is loaded on pairs of the adjacent active sub-carriers. The user equipment (UE) recognizes the mask with index g via power detection of the received frequency domain signal. Then it estimates the index x from differential demodulation followed by detection of the frequency domain se-quence. In order to improve the performance, a method of jointly estimating g and x is devised. Simulation results showed that the proposed scheme is able to support a very large number of cell IDs while maintaining a good performance even in bad multi-cell environment.

Intensity Allocation Criteria of Carbon Emissions Permits and Regional Economic Development in China——Based on a 30-Province/Autonomous Region Computable General Equilibrium Model

The intensity allocation criteria of carbon emissions permits and its influence on China＇s regional development are analyzed through the 30-province/autonomous region computable general equilibrium （CGE） model. Simulation results show that： industrial intensity criteria without taking regional economic development into account deepen the unbalance of regional economic development; regional intensity criteria without taking industrial properties into account exert little negative impact on regional harmonious development, but relatively high negative influence on high-carbon emission industries. The two-step allocation scheme that the central government allocates emissions permits to provincial governments based on regional economic development and then provincial governments allocate emissions permits to emission resources or entities based on industrial properties is a feasible and operable choice.

Analysis of the therapeutic effect of surgical treatment for the gastrointestinal tumor

The gastrointestinal tumor is a disease with the high incidence in our country, and the researches in our country currently on the treatment of the disease are increasingly deep-going. The disease has gradually received widespread attention in the medical field, and the treatment program of the disease and the operational program also made a lot of experts devoted into the relevant researches. This paper cites some practical examples to briefly elaborate the curative effect of the surgical operations on the gastrointestinal tumors and has carried out the summary, hoping to provide certain references for the related researches.

A New Approach for Impulsive Stabilization of Liu's System

An impulsive control scheme of Liu＇s system is presented in this paper. Some less conservative conditions with impulses at fixed times are provided, which can guarantee the global asymptotical stability and global exponential stability for the impulsive control of Liu＇s systems. We also present the estimate of the stable region for the equidistance impulsive interval. Furthermore, an illustrative example is given to show the effectiveness of the proposed results.

Comparative Mountain Hydrology: A Case Study of Wis?ok River in Poland and Chaohe River in China

Hydrological processes in river basins of similar size and morphology may differ significantly due to different climatic conditions. This paper presents a comparative analysis of hydrological characteristics of two river basins located in different climatic zones: the Wisok River Basin in the south-eastern Poland and the Chaohe River Basin in the northern China. The criteria of their choice were similarities in the basin area, main river length and topography. The results show that climate plays a key role in shaping fluvial conditions within the two basins. It is concluded that: 1) precipitation in the Wisok River Basin is more evenly distributed in the yearly cycle, while in the Chaohe River Basin it is highly concentrated in the few summer months; 2) spring snowmelt significantly contributes to runoff in the Wisok River Basin, while its role in the Chaohe River Basin is negligible; 3) in the Wisok River Basin, besides the peak flow in spring, there is also a period of high water in summer resulting from precipitation, while in the Chaohe River Basin there is only one high water period in summer; 4) the Wisok River Basin shows relatively higher stability in terms of the magnitude of intra- and inter-seasonal discharges; 5) during the multi-year observation period, a decrease in both precipitation and runoff was recorded in the two river basins.

Regionalization Methodology Systems of Aquatic Ecosystems in China and the Case Study of Huaihe River Basin

本文提出的水生态区划方法体系包括指导思想、基本原则、分区方法、命名与编码规则几个部分。其核心指导思想是科学发展观及人与自然和谐的理念;基本原则有区域相关性原则、协调原则、主导功能原则和分及区划原则;分区方法、命名与编码规则则随分区等级和研究尺度而异。本文采用2级分区的思路,提出了全国水生态区划分方案,包括6个水生态一级区和34个水生态二级区。基于以下3类7种水生态服务功能:水生态保育类(包括水源涵养、水土保持和物种保护),水生态调控类(包括洪水调蓄和生境维持),水生态服务类(包括产品提供和景观保障),以淮河流域为例,将3级水生态区划方法应用于流域尺度。在实例区共划分出2个水生态一级区、3个水生态二级区和21个水生态三级区。

系统需求视角下的工程变更应对策略研究

工程变更是拟建系统在其项目实施的各个阶段相对于项目基准线的偏差变化。变更对项目的影响不容忽视。基于系统需求域和系统方案域,提出系统需求“之”字形分解模型,作为相关分析的基本工具和思路;对变更应对问题进行系统性梳理,以需求在系统层面的分解应用为核心策略,以时间、逻辑、知识三个维度为划分主线,参考工程实践与理论研究的成果,形成整体的基于系统需求视角的变更应对策略清单,为后续相关方法工具的研究开发打下理论基础。

An upgraded scheme of surface physics for Antarctic ice sheet and its implementation in the WRF model

Regional climate models often lack detailed description of ice sheet surface and, as a result, are limited in their capability to provide useful information for Antarctic climate research and field campaigns. In this study, an upgraded scheme of surface physics for Antarctic ice sheet(IST) is developed to improve the surface temperature simulations in Antarctica. Through stand-alone simulations, IST shows advantages over the Noah glacial module, a commonly utilized scheme in the widely used Weather Research and Forecasting(WRF) model. These improvements are mainly attributed to the incorporation of detailed snow physics and optimized surface layer parameterization, which results in better simulations of both the surface albedo in summer and the turbulent sensible heat flux in winter. When coupled with IST instead of Noah,WRF models show improved simulation of surface temperatures throughout the year. The bias and root-meansquare-error of annual mean surface temperatures are reduced from 5.7 and 6.0 to 0.2 and 2.7 K.

A code-based approach for labeling in complex irregular regions

Labeling information in a complex irregular region is a useful procedure occurring frequently in sheet metal and the furniture industry which will be beneficial in parts management.A fast code-based labeler(FCBL) is proposed to accomplish this objective in this paper.The region is first discretized,and then encoded by the Freeman encoding technique for providing the 2D regional information by 1D codes with redundancies omitted.We enhance the encoding scheme to make it more suitable for our complex problem.Based on the codes,searching algorithms are designed and can be extended with customized constraints.In addition,by introducing a smart optimal direction estimation,the labeling speed and accuracy of FCBL are significantly improved.Experiments with a large range of real data gained from industrial factories demonstrate the stability and millisecond-level speed of FCBL.The proposed method has been integrated into a shipbuilding CAD system,and plays a very important role in ship parts labeling process.