Interference Mitigation in D2D Communication Underlying Cellular Networks:Towards Green Energy

Device to Device(D2D)communication is emerging as a new participant promising technology in 5G cellular networks to promote green energy networks.D2D communication can improve communication delays,spectral efficiency,system capacity,data off-loading,and many other fruitful scenarios where D2D can be implemented.Nevertheless,induction of D2D communication in reuse mode with the conventional cellular network can cause severe interference issues,which can significantly degrade network performance.To reap all the benefits of induction of D2D communication with conventional cellular communication,it is imperative to minimize interference’s detrimental effects.Efficient power control can minimize the negative effects of interference and get benefits promised by D2D communication.In this work,we propose two power control schemes,Power Control Scheme 1(PCS 1)and Power Control Scheme 2(PCS 2),to minimize the interference and provide performance analysis.Simulation results observe improvements with PCS 1 and PCS 2 as compared to without using any power control scheme in terms of data rate in both uplink and downlink communication modes of Cellular User Equipment(CUE).

Traffic prediction enabled dynamic access points switching for energy saving in dense networks

To meet the ever-increasing traffic demand and enhance the coverage of cellular networks,network densification is one of the crucial paradigms of 5G and beyond mobile networks,which can improve system capacity by deploying a large number of Access Points(APs)in the service area.However,since the energy consumption of APs generally accounts for a substantial part of the communication system,how to deal with the consequent energy issue is a challenging task for a mobile network with densely deployed APs.In this paper,we propose an intelligent AP switching on/off scheme to reduce the system energy consumption with the prerequisite of guaranteeing the quality of service,where the signaling overhead is also taken into consideration to ensure the stability of the network.First,based on historical traffic data,a long short-term memory method is introduced to predict the future traffic distribution,by which we can roughly determine when the AP switching operation should be triggered;second,we present an efficient three-step AP selection strategy to determine which of the APs would be switched on or off;third,an AP switching scheme with a threshold is proposed to adjust the switching frequency so as to improve the stability of the system.Experiment results indicate that our proposed traffic forecasting method performs well in practical scenarios,where the normalized root mean square error is within 10%.Furthermore,the achieved energy-saving is more than 28% on average with a reasonable outage probability and switching frequency for an area served by 40 APs in a commercial mobile network.

5G Green Mobile Communication Networks

With the popularization of wireless multimedia communications,the wireless traffic is predicated to be increased more than 1000time in the next decade.Some new technologies,e.g.,massive multi.input multi.output antennas,millimeter wave and small

Project of “Three Networks Greening” based on optimal allocation in the Yellow River Delta,China (Dongying section)

We have used the Yellow River Delta （Dongying section） as our study area to address the project of ＂Three Networks Greening＂ （TNG）. With the use of GIS technology and from an ecological point of view, an optimal allocation scheme of land resources is constructed and applied to guide the adjustment of land resources. Given this scheme, we have calculated that the area of land suitable for forest and shrubs without greening is 2256 km^2. Simultaneously, acting on the layout of the TNG project, afforestation site types are prepared and improved. Soil types, microrelief, salinity and underwater levels are combined as major classification factors and irrigation conditions as a reference to classify sites into eight types. In this way, land suitable for forest and grass is afforested given particular planting patterns. Finally, by overlaying this forestry site type map with the TNG plan map, some suggestions and strategies are proposed and used to direct the TNG project. An ecological oasis of the Yellow River Delta should be the result.

Construction of Ecological Network for Urban Green Space System from the Perspective of Landscape Ecology:A Case Study of Wanzhou District, Chongqing Municipality

Green spaces in Wanzhou District, Chongqing Municipality were not closely linked and failed to form an integrated ecological network, this paper analyzed and assessed current situation of green spaces in the local area from the perspective of landscape ecology, and then established the landscape ecology-oriented ecological network construction, restructured green paces in Wanzhou District using the landscape composition of "patch–corridor–matrix", and connected the scattered green patches using green corridors, so as to form a reasonable ecological network of green spaces.

Optimal Cost-Aware Paradigm for Off-Grid Green Cellular Networks in Oman

Green wireless networks or energy-efficient wireless networks have gained popularity as a research topic due to the ecological and economic concerns of cellular operators.The specific power supply requirements for the cellular base station,such as cost-effectiveness,efficiency,sustainability,and reliability,can be met by utilizing the technological advances in renewable energy.There are numerous drivers for the deployment of renewable energy technologies and the transition towards green energy.Renewable energy is free,clean,and abundant in most locations throughout the year.Accordingly,this work proposes a novel framework for energy-efficient solar-powered base stations for the Oman site,specifically for off-grid locations where fuel transportation for diesel generator(DG)is a serious concern.To demonstrate the effectiveness of the proposed system for off-grid sites,the Hybrid Optimization Model for Electric Renewables optimization software is adapted by considering real-time conditions and its technical feasibility.Different cost factors such as capital cost,salvage cost,replacement cost,operational,and maintenance cost of PV panels,inverters,and batteries also undergo extensive analysis.From the observed results,the total net present cost(NPC)of the proposed system is$27,887,while the net NPC of the DG is estimated at$32,900.Remarkably,the proposed scheme can potentially achieve considerable savings in the operational expenditure at approximately 15.24%.Indeed,these outcomes can provide profound economic,technical,and ecological benefits to the cellular operators of Oman.It also ensures a sizeable reduction in greenhouse gas that supports sustainable green wireless network deployment in remote areas.

Powering Mobile Networks with Optimal Green Energy for Sustainable Development

Green wireless networking is an emerging area for many societies,especially academia and industry,in light of economic and ecological perspectives.Empowering wireless infrastructures exploiting green power sources can enhance sustainability due to the adverse effects of conventional power sources and atmospheric circumstances.Moreover,the specific power supply requirements for a base station(BS),such as cost effectiveness,efficiency,sustainability,and reliability,can be met by utilizing technological advances in renewable energy.Numerous drivers and motivators are involved in the deployment of renewable energy technologies and the transition toward green energy.Renewable energy is free,clean,and abundant in most locations throughout the year.In this work,a sustainable optimal stand-alone solarpowered model envisioning green cellular BSs for urban locations in Oman is proposed.This model can extend 24 h uninterrupted power supply support to a cellular BS that fully utilizes an integrated storage device.The system analysis is conducted using a hybrid optimization model for electric renewables(HOMER)based on actual prevailing conditions of the regions and their technical feasibility.The results showed can be achieved operational expenditure savings up to 16%.These outcomes provide a huge benefit to the cellular operators of Oman economically,technically,and ecologically.

Green Multicast Grooming Based on Cross-Shared Protection in Optical WDM Networks

Currently,multicast survivability in optical network obtains more attention.This paper focuses on the field of multicast grooming shared protection in green optical network and designs a novel auxiliary graph and a shared matrix to address the survivable multicast resource consumption.This paper also proposes a new heuristic called Green Multicast Grooming algorithm based on spanning path Cross-Shared protection(GMGCSP),in which network reliability,energy efficiency and resource utilization are jointly considered.Simulation results testify that,compared to other algorithms,the proposed GMG-CSP not only has lower blocking probability and higher bandwidth utilization ratio,but also saves more energy.

Green Architecture for Dense Home Area Networks Based on Radio-over-Fiber with Data Aggregation Approach

The high-density population leads to crowded cities. The future city is envisaged to encompass a large-scale network with diverse applications and a massive number of interconnected heterogeneous wireless-enabled devices. Hence, green technology elements are crucial to design sustainable and future-proof network architectures. They are the solutions for spectrum scarcity, high latency, interference, energy efficiency, and scalability that occur in dense and heterogeneous wireless networks especially in the home area network （HAN）. Radio-over-fiber （ROF） is a technology candidate to provide a global view of HAN＇s activities that can be leveraged to allocate orthogonal channel communications for enabling wireless-enabled HAN devices transmission, with considering the clustered-frequency-reuse approach. Our proposed network architecture design is mainly focused on enhancing the network throughput and reducing the average network communications latency by proposing a data aggregation unit （DAU）. The performance shows that with the DAU, the average network communications latency reduces significantly while the network throughput is enhanced, compared with the existing ROF architecture without the DAU.

碳市场建立对非控排企业绿色创新的影响研究

以尚未纳入碳交易体系的上市公司为样本,基于溢出效应框架分析碳市场建立对非控排企业环保决策的影响。研究发现,客户被纳入碳市场交易促进了非控排供应商企业的绿色创新。其作用机制在于,碳交易下的控排企业绿色创新具有基于生产网络的压力效应和动力效应,能够激发关联非控排企业的绿色创新意愿,并助推其绿色创新能力提升。这一溢出效应有助于实现非控排企业绿色创新增量提质,且该过程具有方向性,碳市场建立并不存在基于生产网络“自上而下”的治理效果外溢,相关影响在非控排企业客户集中度较高、绿色创新基础较好及环境不确定性较高时更加明显。此外,碳市场建立的绿色创新溢出效应对于推动非控排企业可持续发展具有积极作用。研究结论为高效发挥碳市场绿色治理效果、深化环保改革以促进经济高质量发展提供了管理启示。

外部技术网络嵌入、知识重组能力与制造企业节能减排

在加快发展方式绿色转型的战略部署下,作为绿色转型的关键实施主体,制造企业不断利用网络嵌入和知识重组以促进其在能源消耗和污染排放工作的平稳、有序推进。本文以中国制造业A股上市公司为研究对象,收集整理企业联合申请发明专利数据,采用社会网络分析软件对外部技术网络嵌入的技术网络地位和网络有效规模进行测算,基于“外部合作-知识重组-节能减排”的逻辑思路分别探索外部技术网络嵌入对制造企业节能减排的直接效应,以及从知识重组视角探讨知识再创造和知识再利用在其中的中介作用。结果表明:技术网络地位和网络有效规模显著有利于降低合作企业的能源消耗和污染排放,知识重组能力在技术网络地位与网络有效规模对节能减排的影响中存在显著中介作用。据此提出相应的管理启示以提高制造企业节能减排成效,为推进“统筹发展与绿色低碳转型,深入实施绿色制造”提供一定的经验证据。

基于“生态-气候适应性-游憩”多功能耦合的复合绿地生态网络格局优化

城市生态环境问题日益突出,如何构建多功能耦合的绿地生态网络格局是促进人居环境可持续发展的重要议题。以成都市为研究区,基于“源-汇”理论,综合运用形态学空间格局分析(Morphological Spatial Pattern Analysis,MSPA)、景观连通性指数、电路理论等方法对生物多样性保护、热环境改善、游憩服务构建单因子网络,分析源地、廊道、生态战略点等空间要素特征,形成基于“生态-气候适应性-游憩”多层级、多功能复合生态网络优化格局。结果表明:(1)筛选出“源”-“汇”景观(生态159—29个,气候适应性30—14个,游憩208—40个)。生物迁徙廊道在研究区中部、西南部呈团簇状分布;气候适应性廊道呈中部集聚、东西稀疏的分布特征;游憩廊道相对密集,以中心城区为核心向四周扩散。(2)多层级“源-汇”景观网络中,总长度上,游憩廊道>生物迁徙廊道>气候适应性廊道;总面积上,生物迁徙廊道>游憩廊道>气候适应性廊道。一、二级廊道的适宜宽度为生态廊道200、100m,气候适应性廊道100、60m;游憩廊道60、30m。(3)叠加多目标廊道获得生态关键点753个,干扰点2371个。游憩源地中8.18%的面积应退让给生态廊道和气候适应性廊道。多功能耦合的生态网络优化格局可激活不同景观资源的潜在价值,对协调生态保护与城市发展的双向需求,实现绿地资源在城市空间中的最优配置具有重要意义。

铁路网络联系对城市土地绿色利用效率的影响研究——以长三角地区为例

研究目的:探究铁路网络联系对城市土地绿色利用效率的影响及空间溢出效应,为依托铁路交通发展促进土地绿色利用效率提升提供科学依据。研究方法:超效率SBM模型,社会网络分析方法,空间面板模型。研究结果:(1)长三角城市铁路联系强度和土地绿色利用效率均呈现显著的增长趋势,土地绿色利用效率存在着较为明显的区域差异。(2)铁路联系强度的提高促进了本城市土地绿色利用效率的提升,与综合铁路联系相比,高铁联系对本城市土地绿色利用效率的提升作用更加明显。(3)铁路联系的加强促进了本城市产业结构合理化水平的提升和创新产出的增长,进而对土地绿色利用效率产生影响。高铁联系在促进本城市产业结构合理化水平提升和创新产出增长方面的作用更加明显。(4)城市对外铁路联系强度的提高产生了负向的空间溢出效应,抑制了邻近城市土地绿色利用效率的提升。研究结论:应充分发挥铁路建设在优化产业结构、促进创新方面的作用,依托铁路网络加强区域内经济技术合作、发挥各城市比较优势,以推动区域土地绿色利用效率的整体性提升。

Optimization of the Conceptual Model of Green-Ampt Using Artificial Neural Network Model (ANN) and WMS to Estimate Infiltration Rate of Soil (Case Study: Kakasharaf Watershed, Khorram Abad, Iran)

Determination of the infiltration rate in a watershed is not easy and in empirical and theoretical point of view, it is important to access average value of infiltration. Infiltration models has main role in managing water sources. Therefore different types of models with various degrees of complexity were developed to reach this aim. Most of the estimating methods of soil infiltration are expensive and time consuming and these methods estimate infiltration with hypothesis of zero slope. One of the conceptual and physical models for estimating soil infiltration is Green-Ampt model which is similar to Richard model. This model uses slope factor in estimating infiltration and this is the power point of Green-Ampt model. In this research the empirical model of Green-Ampt was optimized with integrating artificial neural network model (ANN) and a model of geographical information system WMS to estimate the infiltration in Kakasharaf watershed. Results of the comparison between the output of this method and real value of infiltration in region (through multiple cylinders) showed that this method can estimate the infiltration rate of Kakasharaf watershed with low error and acceptable accuracy (Nash-Sutcliff performance coefficient 0.821, square error 0.216, correlation coefficient 0.905 and model error 0.024).

中国绿色创新效率空间关联网络特征及其驱动因素研究

运用基于序列DEA的SE-U-SBM模型测度我国30个省份2007—2019年绿色创新效率,利用修正的引力模型和社会网络分析方法解构了我国省际绿色创新效率的空间关联特征,并借助QAP方法探讨了绿色创新效率空间关联网络的驱动因素。研究结果显示:(1)我国省际绿色创新效率上升趋势明显,呈现东部>中部>西部的空间分布格局。(2)中国绿色创新效率的空间关联呈现出复杂的多线程空间网络关联关系,省际绿色创新效率的关联性不断加强,空间关联网络稳定性进一步增强,东部省份大多属于净溢出板块,中西部省份为相对受益板块。(3)地理距离、城镇化水平差异、人力资本差异、财政分权差异、相近的R&D投入强度和资源禀赋差异是影响我国绿色创新效率空间关联网络形成与发展的重要驱动因素,对绿色创新效率空间关联网络具有显著的促进作用。应着力推动要素市场化改革,破除区域市场分割和行政壁垒,加强区域政策协调性,实现绿色创新效率协同提升。

贸易自由化、企业生产网络与绿色贸易

本文研究了在具有企业间生产网络的背景下,贸易自由化对绿色贸易的影响规模及机制。本文采用HITS算法创新地构建了中国企业的生产网络中心度指标数据,建立了包含中间品进口、最终品出口和污染排放的生产网络理论模型,并进行理论与实证分析。研究发现:贸易自由化有利于企业降低出口排放强度,实现绿色贸易的发展,并且该促进作用随着企业网络中心度的上升而不断增强,主要影响渠道来自规模效应、结构效应和技术效应。区分行业上游度来看,处于最上游位置行业的生产网络调节作用不明显,处于最下游位置行业的网络中心度对出口贸易自由化的调节作用较为显著,而居中行业的网络中心度对进口中间品贸易自由化的调节作用较为显著,区分地区来看,生产网络的调节作用对东部企业显著,而对中西部企业不显著.

数字化环境监测与企业绿色创新——基于环境监测网络建设的准自然实验

数字化环境监测将数字技术应用于环境监测领域,旨在提升政府环境治理决策的科学性,而实现海量监测数据互联互通的关键是构建生态环境监测网络。本文基于2013—2020年沪深A股上市公司的绿色专利数据,利用各省份陆续出台生态环境监测网络建设方案事件构建强度双重差分模型,检验数字化环境监测的微观创新效应及其机制。研究发现,环境监测网络建设能够促进企业绿色创新,且政府环境执法和环保补贴的效率优化是实现环境监测效应的有效路径。进一步检验发现,对于政府数字化水平较高、联网监控的重点排污单位占比较高的省份、环境规制强度较高的地市以及研发投入较高的企业,环境监测效应更明显。此外,环境监测网络建设对企业绿色创新的数量和质量均有显著的提升作用。本文从微观层面提供数字化环境监测促进企业绿色创新的积极证据,拓展了环境监测效应及企业绿色创新影响因素相关文献,对新时期推动数字政府建设和实现经济绿色发展具有一定启示。

基于街区小气候环境冬夏协同优化的城市绿地生态网络精准修复

越来越多城市绿地生态网络建设进入存量更新和结构性优化并存发展的阶段,生态安全优先基础上如何进一步提升城市绿地生态网络的多种生态系统服务功能是当前风景园林实践研究的重要议题。应对全球气候变化、极端天气多发导致的人居环境宜居性下降问题,目前基于气候适应的城市绿地生态网络规划关注促进自然通风以缓解夏季热岛效应,尚忽视了其冬季可能带来的负效应。从气候调节视角切入,探讨城市绿地生态网络在协同冬夏季小气候环境中的低效空间识别与精准修复技术方法。以江苏省昆山市密集城区的189个街区单元为研究对象,通过遥感反演的方法对其冬、夏季小气候环境进行分析,聚类获得7类小气候特征街区。之后,叠加现状绿地生态网络与计算流体力学模拟风环境结果,提取现状适于通风的生态廊道,从宽度、方向、类型等方面分析其潜在通风效能,耦合街区冬夏小气候环境特征,识别研判现状绿地生态网络在冬夏温湿环境调节上存在的低效问题,并提出冬夏协同的精准修复策略,为优化人居环境宜居性、提升城市绿地生态网络生态系统服务综合效能提供技术参考。

基于生境网络构建优化的生物多样性保护规划途径研究

城市绿色空间是承载生物多样性的关键,以其为基础构建生境网络有助于整合破碎绿地斑块,促进物种交流与迁徙,为生物多样性保护提供基础。现有生境网络构建过程中存在依赖单一模型、忽略区域实际物种情况、网络构建的工作路径尚未统一、输出成果难以与上位规划衔接并在规划层面进行实践应用等问题。在明确生物多样性保护规划工作内容与目标的基础上,综合运用生境质量分析、地理探测器、最小累积阻力模型等模型方法,识别区域生境源地和廊道,并在考虑区域指示物种的基础上补充重要生境节点,构建面向生物多样性保护的生境网络,系统优化了“源地识别-廊道模拟-节点提取-网络构建”的网络构建方法;以对接国土空间规划下的绿地系统专项规划为目标,将生境网络构建结果通过红线比对、绿地分类匹配等途径,从空间管控角度提出保护措施,实现与绿地系统规划的有效衔接,构建统一规范的生物多样性保护规划工作路径,以通城县为例验证工作路径的可行性,优化面向生物多样性保护的生境网络构建方法,为县域绿地系统规划与生物多样性保护规划提供科学依据。