Propagation Characteristics of Elevation Angles and Three Dimensional Fading Channel Model with Angle Offset

Three dimensional(3D)Multiple Input and Multiple Output(MIMO)is one of the most promising techniques for the 5th generation(5G)mobile communication system.To support its research,the property of elevation angle in 3D channel model should be accurately modeled.Conventionally,3D channel is modeled with an assumption that the mean elevation angle of multipaths is coincided with the line-of-sight(LOS)direction.In order to investigate its authenticity and give the reliable 3D channel model,extensive 3D multiple antenna field channel measurements with 100 MHz bandwidth are conducted in three typical scenarios,including outdoor to indoor(O2I),urban microcell(UMi)and urban macrocell(UMa).The statistical characteristics and parameters are extracted and analyzed based on the measurement data.It is found that the assumption holds in the LOS condition.However,for non-line-of-sight(NLOS)condition,a difference exists between the mean elevation angle and the direction connecting transmitter and receiver,which is defined as the elevation angle offset.Then,the eigenvalue distribution and capacity are compared between the reconstructed 3D channels with and without elevation angle offset.Results show that the performance of 3D channel with angle offset fits the measurement data better whereas that without angle offset is underestimated.

On the Innovation of Marketing Channel Modes of China's Seed Industry

In China,the seed industry has fierce competition. The situation of homogeneous management and homogeneous products is serious. A key problem is simple and outmoded marketing channel of seed. It threatens sustainable development of seed enterprises. At present,the two-level distribution channel of seed industry has problems of similarity,low access threshold,and unfair benefit distribution,and thus urgently needs innovation. The innovation of distribution channel is inevitable requirement for promoting reorganization of China's seed industry and building of new order,is necessary weapon for dealing with trans-national seed industry competition,is essential measure for lifting the overall service level of seed industry,and is also essential means for conforming to stage development of China's agriculture. The innovation of seed marketing channel should consider changes of future agricultural development,deep-level demand of industrial market and services,scitech development level,fair distribution of industrial profit,and differentiated competition. It is recommended that channel innovation should follow the flat principle,have new and unique conception,give full play connection advantage of marginal industry,realize complementary advantages and mutual promotion,strengthen service awareness,combine with agricultural development trend,and seek sci-tech innovation of channel carrier- variety.

Vortex Channel Modelling for the Radio Vortex System

In this paper, a free-space vortex channel model of the radio vortex system is proposed to describe the propagation characteristics of vortex signals over the vortex channel. The key idea is to combine the Laguerre-Gaussian(LG) modes in the optical field with the free-space propagation model in the radio field. The proposed free-space vortex channel model is derived from the electric field expression of the LG modes and the freespace channel transfer function of the freespace propagation model theoretically. Simulation results verify that the proposed model could reflect the vortex channel characteristics better than the currently used free-space propagation model.

Mode Selection Strategy of Dual Distribution Channel Based on Revenue Analysis

Within the scope of dual distribution channel(DDC)modes—ME&T-C and M-T&E-C,a game model designed for channel members was proposed.Based on this game model,the game equilibrium under both centralized and decentralized decisionmaking situations was analyzed,the channel members' and overall revenues of two modes under the same decision-making situation are compared,and the influence of demand shift coefficient to the overall and members' revenue was also studied through example analysis.Based on the comparison and analysis of the revenue yielded from the two DDC modes,it's discovered that within a certain hypothetical range,the M-T&E-C mode seems to be a better option for the manufacturer than the ME&T-C mode.Therefore,this discovery can be served as a theoretical reference for manufacturers when choosing the optimal DDC mode in real life.

STABILITY ANALYSIS IN SPATIAL MODE FOR CHANNEL FLOW OF FIBER SUSPENSIONS

Different from previous temporal evolution assumption, the spatially growing mode was employed to analyze the linear stability for the channel flow of fiber suspensions. The stability equation applicable to fiber suspensions was established and solutions for a wide range of Reynolds number and angular frequency were given numerically . The results show that, the flow instability is governed by a parameter H which represents a ratio between the axial stretching resistance of fiber and the inertial force of the fluid. An increase of H leads to a raise of the critical Reynolds number, a decrease of corresponding wave number, a slowdown of the decreasing of phase velocity , a growth of the spatial attenuation rate and a diminishment of the peak value of disturbance velocity. Although the unstable region is reduced on the whole, long wave disturbances are susceptible to fibers.

New Channel-Aware Modes for VoIP in 3GPP EVS Codec

Aiming at improving rate flexibility of the enhanced voice services (EVS) channel-aware mode for various VoIP applications, two new bit-rate channel-aware modes are proposed in this paper in addition to the existing 13.2 kbit/s mode. Channel-aware mode uses forward error correction by transmitting re-encoded information redundantly for use when the original information is lost or discarded due to late arrival to the receiver. The primary frame bit rate is reduced for the redundant accommodation. A modified quantization scheme is proposed for core encoding regarding the quality degradation. Partial redundant coding is a simplification of that in the existing 13.2 kbit/s channel-aware mode due to the bit constraint. The objective evaluation results of PESQ show that the additional channel-aware modes achieve similar performance in improving the error robustness against missing packets as that of the existing 13.2 kbit/s mode. Multiple bit-rate modes can be dynamically selected in the communication system for more voice services in different bandwidths. On the other hand, optimal allocation based on real-time feedback can adapt to the rapidly-changing network environment as well as possible.

Role of the Oceanic Channel in the Relationships between the Basin/Dipole Mode of SST Anomalies in the Tropical Indian Ocean and ENSO Transition

The relationships between the tropical Indian Ocean basin （IOB）/dipole （IOD） mode of SST anomalies （SSTAs） and ENSO phase transition during the following year are examined and compared in observations for the period 1958-2008. Both partial correlation analysis and composite analysis show that both the positive （negative） phase of the lOB and IOD （independent of each other） in the tropical Indian Ocean are possible contributors to the E1 Nino （La Nifia） decay and phase transition to La Nifia （El Nifio） about one year later. However, the influence on ENSO transition induced by the IOB is stronger than that by the IOD. The SSTAs in the equatorial central-eastern Pacific in the coming year originate from subsurface temperature anomalies in the equatorial eastern Indian and western Pacific Ocean, induced by the IOB and IOD through eastward and upward propagation to meet the surface. During this process, however the contribution of the oceanic channel process between the tropical Indian and Pacific oceans is totally different for the IOB and IOD. For the IOD, the influence of the Indonesian Throughflow transport anomalies could propagate to the eastern Pacific to induce the ENSO transition. For the IOB, the impact of the oceanic channel stays and disappears in the western Pacific without propagation to the eastern Pacific.

Dissipation of a two-mode squeezed vacuum state in the single-mode amplitude damping channel

We explore how a two-mode squeezed vacuum state sechθeab tanh θ[00） evolves when it undergoes a single- mode amplitude dissipative channel with rate of decay k. We find that in this process not only the squeezing parameter decreases, tanhθ → e-kt tanh θ, but also the second-mode vacuum state evolves into a chaotic state exp{bbln[（1 - e-2kt） tanh2 θ]}. The outcome state is no more a pure state, but an entangled mixed state.

Groove-type channel enhancement-mode Al GaN/GaN MIS HEMT with combined polar and nonpolar AlGaN/GaN heterostructures

A novel groove-type channel enhancement-mode AlGaN/GaN MIS high electron mobility transistor（GTCE-HEMT）with a combined polar and nonpolar AlGaN/GaN heterostucture is presented. The device simulation shows a threshold voltage of 1.24 V, peak transconductance of 182 m S/mm, and subthreshold slope of 85 m V/dec, which are obtained by adjusting the device parameters. Interestingly, it is possible to control the threshold voltage accurately without precisely controlling the etching depth in fabrication by adopting this structure. Besides, the breakdown voltage（VB） is significantly increased by 78% in comparison with the value of the conventional MIS-HEMT. Moreover, the fabrication process of the novel device is entirely compatible with that of the conventional depletion-mode（D-mode） polar AlGaN/GaN HEMT. It presents a promising way to realize the switch application and the E/D-mode logic circuits.

小浪底水库减淤调度模式探讨

小浪底水库在黄河中下游防洪格局中发挥着重要作用,长期保持库区较大库容、延长拦沙运用期,对黄河防洪保安具有重大意义。基于小浪底水库运用以来入库水沙条件变化以及调度实践分析,提出了近期小浪底水库减淤调度模式:前汛期洪水期考虑下游河道淤积和主槽过流能力,尽量利用大流量过程开展降低水位排沙运用,冲刷库区河槽新增淤积物,以恢复河槽过流能力,保持库区高效输沙通道;水库排沙运用过后,运用水位宜不高于库区较大滩地滩面,利用河槽输沙调沙能够有效减缓滩面淤积;后汛期在保证防洪安全的前提下,根据上游来沙情况择机开展水库回蓄,尽早将库水位蓄至HH37断面附近滩面以上,利用HH37断面以上库段临时调沙,减缓滩面淤积。

考虑绿色研发结果不确定性的供应链渠道模式选择研究

本文研究了绿色技术研发结果不确定时制造商与零售商在传统线上平台以及区块链平台进行销售时的渠道模式选择问题。同时考虑服务水平差异性和营销努力水平,运用斯塔克伯格博弈和卡特尔模型,分析了研发结果不确定时基于传统线上平台和区块链平台四种不同决策模式下的最优绿色技术研发水平、营销水平、服务水平、定价与利润,并对四种情形进行了比较分析。研究结果表明:(1)不论是传统线上平台还是区块链平台,绿色技术研发成功时的制造商与零售商的利润均高于研发失败时的利润。(2)制造商与零售商选择何种渠道模式主要取决于区块链平台带来的间接收益水平。(3)零售商的利润随着区块链平台带来的间接收益的下降而下降,当间接收益下降到一定程度时,零售商倾向于采取传统线上平台。

主要国际大通道形成模式、运维经验及对中国的启示

国际大通道内涵丰富,形成模式多样,融合性强,目前学界、业界尚无统一定义;但其在全球化持续深入背景下,对国家、地区乃至全球发展的基础性、战略性作用日益突出。马六甲海峡、苏伊士运河等主要国际大通道的稳定发展,得益于相关政府的科学规划、协同联动,以及企业主体的国际化运作和绿色、数字实践等。我国对现代国际大通道的建设、研究等起步晚、基础弱,应深入研究国际大通道发展情况,借鉴相关国家政府、企业的经验做法,提升国际大通道建设、维护和把控能力,充分利用国际大通道促进高水平对外开放,推动共建“一带一路”高质量发展,保障我国全球利益和发展安全,推动构建国内国际双循环新发展格局。

双渠道供应链两类退货模式的比较研究

研究双渠道供应链的两类退货模式:传统渠道退货(消费者通过购买渠道实施退货)和上门退货模式(线下上门退货、线上退货补偿)。通过刻画交叉收益(零售商因消费者退货时的额外购买行为所得收益)等因素,构建两类退货模式下的双渠道决策模型并实施比较研究。研究发现:合适的交叉收益和退货服务费是两类退货模式得以实施的条件;传统退货模式下,线下退货产生的交叉收益可弥补退货服务给双渠道零售商带来的损失;上门退货模式下,合理的交叉收益依然是保证双渠道零售商总利润的重要因素。数值分析显示,消费者对线上渠道产品的认知度不会影响两类退货模式下总利润的对比结果;只有当交叉收益较大且退货服务费较小时,上门退货模式的双渠道总利润才优于传统退货模式。

基于双模式分解多通道输入的VSC-STATCOM逆变器故障诊断模型

针对传统电压源型静止同步补偿器中逆变器故障诊断存在的信号特征提取不充分,深度学习网络识别能力不足以及高噪声情况下识别率较低等问题,提出了一种基于双模式分解、多通道输入(MCI)、并行卷积神经网络(PCNN)、双向长短时记忆(BiLSTM)网络和自注意力(SA)机制组合的逆变器故障诊断方法。首先利用变分模态分解和时变滤波经验模态分解对逆变器输出的三相电流进行分解,降低原始信号复杂程度,实现不同模态分量间的规律互补;其次,利用MCI-PCNN-BiLSTM-SA组合模型对特征矩阵进行深层特征提取、学习和识别;最后,通过仿真进行验证,结果表明所提方法特征提取能力较强,在无噪声情况下平均识别率高达99.48%,在高噪声情况下平均识别率达95.59%。

特色农产品全渠道模式下供应链协同发展路径探究

全渠道模式下供应链协同发展是企业在多渠道销售环境下的重要路径。该模式要求企业整合线上线下渠道资源,建立数据共享与分析平台,加强供应链伙伴关系,优化物流网络以及提升顾客体验与服务水平,实现供应链各环节的协同发展,增强运营效率和顾客满意度,提高整体竞争力和市场占有率。由此,特色农产品应重视全渠道模式发展,促进产业供应链的协同,完善产业供应链运营管理。

不锈钢槽式预埋组件受剪性能研究

为研究不锈钢槽式预埋组件在剪力作用下的破坏模式和承载性能,完成了3组9个带混凝土基材的不锈钢槽式预埋组件试件的受剪试验。试验结果表明,平行受剪工况下破坏模式为齿牙剪切破坏,垂直受剪工况下破坏模式为混凝土边缘破坏及槽道卷边受弯破坏。在试验的基础上,通过ABAQUS软件建立了有限元分析模型,并验证了模型的准确性。通过数值分析研究了齿牙尺寸、混凝土强度、边缘距离、锚件中心线间距及预埋槽道有效埋深等参数对极限承载力的影响。结果表明,平行受剪工况下,平齿型槽道的齿牙数量、宽度及厚度的增加均可提高极限承载力,齿牙高度对极限承载力影响较小;垂直受剪工况下,平齿型和燕尾型槽道的混凝土强度及边缘距离的增加均可提高极限承载力,而锚件中心线间距的增加则使极限承载力降低,预埋槽道有效深度对极限承载力影响较小。给出了不同破坏模式下的受剪承载力计算公式,通过试验结果与有限元模拟结果的对比,验证了承载力计算公式的有效性。

高速公路监控网络可补偿信道增益系统设计

为解决高速公路监控图像与信道组织内数据增量值不匹配的问题,从而提升监控信息的实时传输速率,设计高速公路监控网络的可补偿信道增益系统。在可调式VGA结构体系中,连接增益放大器、峰值检测器与视频车辆检测器,完成可补偿信道增益系统的硬件设计。建立Flex服务模式,并以此为基础,定义完整的Access数据库表,实现高速公路监控网络中的GIS数据准备,联合相关硬件结构,完成高速公路监控网络可补偿信道增益系统的设计。实验结果表明,该系统可将监控图像补偿残差与信道组织内数据增量之间的差值控制在0~2.5×10^(9) bit的数值范围内,能够有效解决图像与增量值不匹配的问题,符合提升高速公路监控信息实时传输速率的实际应用需求。