Pricing Based Power Control for Inter-Cell UAV-Assisted Vehicle-to-Vehicle Underlay Communication

The high-capacity vehicle-to-vehicle(V2 V) communication provides a promising solution to support ubiquitous media streaming and content sharing among vehicles.To extend the V2 V links to multiple cells and manage the inter-cell interference,we proposed an UAV-assisted inter-cell V2 V communication model,in which a shared UAV node is placed in the center of V2 V users.By charging the V2 V users underlay spectrum access fee,the cellular network earn profit at the cost of encountering co-channel interference from V2 V links.A Stackelberg game is formulated to model the interactions between the V2 V links and the cellular links,which are the game follower and the leader respectively.Their utility functions are maximized in terms of accessing price as well as transmit power of V2 V users and UAV relays.Simulation evaluations verify that the power-price tradeoff between V2 V network and cellular network has significant potentials to enhance their utility.

COOPERATIVE DIRECTIONAL INTER-CELL HANDOVER SCHEME IN HIGH ALTITUDE PLATFORM COMMUNICATIONS SYSTEMS

A novel Cooperative Directional inter-cell Handover Scheme(CDHS) for High Altitude Platform(HAP) communications systems is proposed,in which the handover target cell and the two cells adjacent to this handover target cell work cooperatively to exploit the traffic fluctuation to improve handover performance.Users in the overlap area of the overloaded handover target cell will be forced to handover directionally before their optimal handover boundary in order to free up resources for the handover calls which would otherwise be dropped due to the shortage of resources and queue time out.Simulation results show that the handover call dropping probability is greatly reduced(at least 60%) compared with the general queue handover scheme,with little performance reduction to the call blocking probability,and the Not in the Best Cell(NBC) average time is only increased moderately.Moreover,an optimal cell radius can be achieved for a specific platform speed by minimizing the unified system performance,which is the linear combination of the handover call dropping probability and the NBC average time.

Congestion Relief in Downlink OFDMA Cellular System Using Inter-Cell Relay

This paper proposes the concept of inter-cell relay for downlink orthogonal frequency division multiple access(OFDMA) cellular systems, which uses multi-hop to relay calls from overloaded cells to light-load neighboring cells. It is shown that when using inter-cell relay, the number of calls in the congestion cell can be significantly increased. The congestion cell is divided into two parts. One is called non-relay area(NRA), in which a call directly communicates with the base station(BS) of a congested cell. The other is called relay area(RA), in which a call communicates with the BS of a neighboring cell through a relay station(RS). The two parts have different user-call densities. By adjusting the densities of two parts, we will maximize the number of supported calls inside a congested cell. The results show the benefits gained from inter-cell relay in congestion relief, which can reduce cell congestion by fully utilizing the available resources in the neighboring cells.

Inter-Cell Interference Cancellation Algorithm for Reverse Link TDD-CDMA Systems

This paper proposes a new inter-cell interference cancellation algorithm called subspace projection in order to eliminate the stronger inter-cell interference. This algorithm is designed for the reverse link of time division duplex-code division multiple access systems. The algorithm works by projecting desired users＇ signal vector onto the subspace orthogonal to the subspace that inferrers the users＇ signal. Link-level simulation results show that the scheme eliminates the inter-cell interference efficiently, improves the receiver performance, and increases the system capacity.

Multicell power allocation method based on game theory for inter-cell interference coordination

As a new technology, coordinated multipoint （CoMP） transmission is included in LTE-Advanced study item. Moreover, the network architecture in LTE-Advanced system is modified to take into account coordinated transmission. Under this background, a novel power allocation game model is established to mitigate inter-cell interference with cellular coordination. In the light of cellular cooperation relationship and centralized control in eNodeB, the power allocation in each served antenna unit aims to make signal to interference plus noise ratio （SINR） balanced among inter-cells. Through the proposed power allocation game algorithm, the users＇ SINR can reach the Nash equilibrium, making it feasible to reduce the co-frequency interference by decreasing the transmitted power. Numerical results show that the proposed power allocation algorithm improves the throughput both in cell-center and cell-edge. Moreover, the blocking rate in cell-edge is reduced too.

Performance of power control in inter-cell interference coordination for frequency reuse

To mitigate inter-cell interference in 3G evolution systems, a novel inter-cell interference coordination scheme called soft fractional frequency reuse is proposed in this article, which enables to improve the data rate in cell-edge. On this basis, an inter-cell power control is presented for the inter-cell interference coordination, and the inter-cell balanced signal to interference plus noise ratio （SINR） among users is established for power allocation, which enables mitigation of inter-cell interference. Especially, the power control is based on a novel exponential kernel arithmetic kernel equations. Numerical results show that the proposed rate compared to the existing power control algorithms. equation at higher convergence speed than the traditional scheme improves the throughput and reduces the blocking

Approximate inter-cell interference modeling for cellular network

In this paper, we develop and analyze several inter-cell interference modeling methods for cellular network. The models can analyze multiple interfering signals under different fading scenarios. Incoherent addition of summing multiple interfering signals is assumed. We propose an approximate method that uses the generalized Gram-Charlier series to analyze the error of the reference model. The approximate method is not only simple but also with neglectable errors. The methods proposed could be very useful in practical system design and analysis.

基于K-means聚类的超启发式跨单元调度方法

结合我国制造业实际生产状况,针对柔性作业车间跨单元调度问题,提出一种基于K-means聚类的超启发式算法。应用K-means聚类算法将相近属性的实体划入相应“工件簇”决策块中,采用蚁群算法为每个决策块选择启发式规则;对每个决策块内的实体运用相应的启发式规则产生调度解。仿真结果表明:该算法以决策块的形式适度增大了计算粒度,有效降低了算法时间复杂度,以聚类的方式将具有相近属性的被加工实体进行聚集,有利于为不同属性的实体选择合适的规则。该算法提高了计算效率,具有较好的优化性能,是解决柔性跨单元调度的一种有效算法。

帝迈DM79x血细胞分析仪的精密度和准确度情况分析

目的通过比对室内质控数据,评估4台DM79x血细胞分析仪在医院检验科每日室内质量控制中最宜工作状态下的精密度和准确度水平,提高检验结果准确性和一致性。方法统计2023年2月份(28天)实验室4台仪器使用原装低、中、高定值质控品以及每日检测一份随机门诊新鲜患者样本的室内质控数据,项目包括:白细胞(WBC)、红细胞(RBC)、血红蛋白(HGB)、血细胞比容(HCT)、血小板(PLT)、平均红细胞体积(MCV)、平均红细胞血红蛋白量(MCH)、平均红细胞血红蛋白浓度(MCHC),计算平均值(-X)、标准差(S)和变异系数(CV),以变异系数指数(CVI)和标准差指数(SDI)分别作为精密度和准确度评价指标。结果DM79x 4台仪器间室内质控比对,统计分析发现仪器对血细胞分析包括WBC、RBC、HGB、PLT、HCT、MCV、MCH、MCHC 8项参数,每台仪器的CVI不一,SDI室内质控测定结果<2.0,新鲜样本比对数据CVI、SDI的测定值均在要求范围内。结论医院检验科4台DM79x型全自动血细胞分析仪通过比对实验室间室内质量控制数据,具有良好的精密度和高准确度,仪器性能可满足临床实验室的工作需求,且通过患者新鲜样本比对,确保结果在不同仪器的准确性和一致性。

血清ITIH4和MCL-1水平与急性缺血性脑卒中患者病情程度及预后的关系

目的探究急性缺血性脑卒中(AIS)患者血清间α胰蛋白酶抑制因子重链4(ITIH4)、髓样细胞白血病因子-1(MCL-1)表达与病情程度及预后的关系。方法纳入2019年7月—2022年7月河南科技大学附属黄河医院神经内科诊治AIS患者128例为AIS组。根据入院时美国国立卫生研究院卒中量表(NIHSS)评分,分为轻度亚组(NIHSS<6分,n=42)、中度亚组(NIHSS 6~<14分,n=52)和重度亚组(NIHSS≥14分,n=34)。根据出院3个月时AIS患者改良Rankins评分,分为预后不良亚组(mRS评分>2分,30例)和预后良好亚组(mRS评分≤2分,98例)。另选取同期医院体检的健康人70例为健康对照组。酶联免疫吸附试验检测血清ITIH4、MCL-1水平。Pearson相关分析血清ITIH4、MCL-1水平与病情程度及预后的相关性;多因素Logistic回归分析影响AIS患者预后的因素;受试者工作特征曲线分析血清ITIH4、MCL-1对AIS患者预后的预测价值。结果AIS组患者血清ITIH4、MCL-1水平显著低于健康对照组(t/P=43.211/<0.001,43.191/<0.001);病情程度越重,AIS患者血清ITIH4/MCL-1水平越低(F/P=107.796/<0.001,297.976/<0.001);预后不良亚组梗死面积、入院24 h NIHSS评分高于预后良好亚组(t/P=9.637/<0.001,9.752/<0.001),血清ITIH4、MCL-1水平及出院3个月简易智能状态量表(MMSE)评分、蒙特利尔认知评估量表(MoCA)评分低于预后良好亚组(t/P=26.723/<0.001,11.709/<0.001,13.674/<0.001,10.782/<0.001);AIS患者血清ITIH4、MCL-1与梗死面积、入院24 h NIHSS评分呈负相关(r/P=-0.705/<0.001,-0.685/<0.001;-0.761/<0.001,-0.619/<0.001),与出院3个月MMSE评分、MoCA评分呈正相关(r/P=0.656/<0.001,0.632/<0.001;0.751/<0.001,0.789/<0.001);出院3个月MMSE评分高、出院3个月MoCA评分高是影响AIS患者预后不良的独立保护因素[0.622(0.446~0.868),0.606(0.427~0.861)],血清ITIH4低、MCL-1低、梗死面积大、入院24 h NIHSS评分高是危险因素[OR(95%CI)=1.467(1.150~1.870),1.415(1.094~1.829),1.605(1.168~2.205),1.765(1.233~2.526)];血清ITIH4、MCL-1及两项联合预测AIS预后不良的AUC分别为0.811、0.835、0.923,两项联合预测AIS预后不良的AUC大于单一指标,差异具有统计学意义(Z=4.258、4.119,P均<0.001)。结论AIS患者血清ITIH4、MCL-1表达下调,两者表达水平与病情严重程度有关,两者联合对AIS患者预后具有较高的预测价值。

5G抗干扰技术综述

5G技术不仅在以蜂窝网络为代表的移动互联网中占据主要角色,还正在积极地为工业场景提供技术变革的契机.目前,国内外已经开展了大量和5G抗干扰技术相关的工作,但仍缺乏对5G在授权和非授权频谱下抗干扰技术的系统性综述.本文分析了5G无线干扰的主要来源,指出了抗干扰研究的技术难点,并以授权频段5G蜂窝网络干扰与非授权频段异构系统间干扰两个关键问题为例,对现有的无线抗干扰方案进行了具体分析和归纳对比,最后对5G技术在授权频段和非授权频段抗干扰技术的未来研究方向进行了展望.

面向5G毫米波通信中基于深度图搜索的波束干扰协调

在毫米波(Millimeter Wave,mmWave)通信中,波束成形(Beam Forming,BF)技术使得小区间的干扰模型不同于工作在低频带的情况,小区间干扰(Inter-Cell Interference,ICI)的影响随着小区密度的增加而增加.为了解决毫米波小区间波束干扰研究中较多的信道状态信息反馈的开销和较高的计算复杂度问题,以时隙调度波束为基础设计了多个小区的波束调度算法.首先针对相邻的毫米波小区在同一时隙向同一边缘用户进行服务会产生较差的传输质量这一特征,构建了波束冲突矩阵.其次充分考虑用户需求的不同服务时隙数量,不同的小区波数数量,小区链路数有限等限制条件,提出了一种基于深度图搜索的波束干扰协调算法.仿真结果表明:所提算法能够明显降低波束碰撞的数量,提高信噪比,改善网络和速率.

聚光光伏系统太阳能电池散热技术及发展现状

低碳政策下新能源的高效利用势在必行,有效利用太阳能聚光光伏技术的核心为太阳能电池,太阳能电池对温度的变化非常敏感,高温会大幅降低太阳能电池的性能及寿命,因此,太阳能电池的有效散热是限制该技术发展的瓶颈。本文首先介绍了聚光太阳能电池散热的必要性及散热难题,随后根据电池结构和热沉装置之间是否存在壁面,从间壁式冷却和直接接触式冷却两个角度回顾了近年来国内外在电池冷却技术方面的研究现状及最新进展。最后,通过各冷却技术的冷却效果和电池性能增益对比分析了各冷却方式的优缺点和未来的研究重点,为聚光光伏系统太阳能电池的有效散热提供了参考与借鉴。

长链非编码RNA HOX转录反义RNA靶向miR-206对结直肠癌细胞迁移、侵袭的影响

目的探讨长链非编码RNA(lncRNA)HOX转录反义RNA(HOTAIR)靶向miR-206对结直肠癌细胞侵袭和迁移的影响。方法常规培养人结直肠癌HT-29细胞,将合成的HOTAIR si RNA和siRNA control转染于HT-29细胞,设置为si-HOTAIR组、si-con组,未进行转染的HT-29细胞设置为空白组。实时荧光定量聚合酶链反应测定转染效果,Transwell和划痕愈合实验检测HT-29细胞侵袭和迁移情况。生物信息学软件分析HOTAIR与miR-206区域结合位点,构建突变型(HOTAIR 3’UTR mut)和野生型(HOTAIR 3’UTR wt)萤光素酶报告载体,将HOTAIR 3’UTR wt、HOTAIR 3’UTR mut与miR-206 mimic或miR-NC载体共转染至HT-29细胞中,设为HOTAIR 3’UTRwt/miR-NC组、HOTAIR3’UTRwt/miR-206组、HOTAIR3’UTRmut/miR-NC组,HOTAIR3’UTRmut/miR-206组,培养48 h后检测萤光素酶活性。将HOTAIR si RNA和miR-206 inhibitor共转染于HT-29细胞,设置si-HOTAIR+anti-NC组和si-HOTAIR+anti-miR-206组,用Transwell和划痕愈合实验分析细胞侵袭、迁移水平。结果空白组与si-con组HT-29细胞中HOTAIR m RNA的表达水平比较,差异无统计学意义(P>0.05);与si-con组比较,si-HOTAIR组HT-29细胞中HOTAIR m RNA的表达水平降低(P<0.01)。空白组与si-con组HT-29细胞侵袭数目、细胞划痕愈合率比较,差异无统计学意义(P>0.05);与si-con组比较,si-HOTAIR组HT-29细胞侵袭数目减少,细胞划痕愈合率降低(P<0.01)。与HOTAIR 3’UTR wt/miR-NC组比较,HOTAIR 3’UTR wt/miR-206组中HOTAIR wt的萤光素酶活性下降(P<0.01);而HOTAIR 3’UTR mut/miR-NC组与HOTAIR 3’UTR mut/miR-206组萤光素酶活性比较,差异无统计学意义(P>0.05)。与si-HOTAIR+anti-NC组比较,si-HOTAIR+anti-miR-206组中miR-206的表达水平降低(P<0.01)。与si-HOTAIR+anti-NC组比较,si-HOTAIR+anti-miR-206组中HT-29细胞的侵袭和迁移率增加(P<0.01)。结论HOTAIR通过负调控miR-206促进HT-29细胞的侵袭和迁移能力。

基于深度强化学习的无人机小区间干扰抑制技术研究

无人机(UAV)辅助蜂窝网络的空中基站工作在频谱高度拥挤的场景中,会造成严重空中小区间干扰(Inter-Cell Interference, ICI)而大大降低网络性能。为解决该问题,研究了基于深度强化学习的无人机辅助蜂窝网络小区间干扰抑制技术。首先建立了无人机辅助蜂窝网络中基于联合波束成形与功率控制(Joint Beamforming and Power Control, JBPC)的抗干扰优化模型。然后提出了基于置信区间上界(Upper Confidence Bound, UCB) Dueling深度Q网络(Deep Q Network, DQN)的深度强化学习求解算法,并利用该算法设计了联合波束成形和功率控制的ICI抑制技术。仿真结果表明,基于UCB Dueling DQN学习的JBPC干扰抑制技术的收敛性优于DQN和Dueling DQN算法,且能达到穷举法的最优容量,有利于提高无人机辅助蜂窝网络性能。

大型基础设施项目融资风险动态评价体系研究

提出以＂融资风险阶段划分—分担—评价＂为主线的融资风险评价体系。基于＂新两阶段论＂把融资风险划分为缔约阶段融资风险和履约阶段融资风险;针对划分后的融资风险,构建灰色关联度和TOPSIS法相结合的分担模型;利用遗传算法优化支持向量机,在融资风险分担完成后,对融资风险展开评价;以青岛胶州湾海底隧道为例进行实证研究。研究表明：该评价体系实现了＂动态性＂＂针对性＂和＂准确性＂,是科学合理的,可以为大型基础设施项目中各利益攸关方及时准确地掌握各自的融资风险状况提供帮助。

LTE-A中继网络中基于小区间干扰协调的分布式资源分配

针对LTE-A(long term evolution-advanced)中继系统存在的干扰问题,提出一种基于小区间干扰协调(inter cell interference coordination,ICIC)的资源分配算法。该算法利用LTE-A网络里各个小区基站之间的交互信息,得到邻小区资源块(resource block,RB)的使用状况,将空闲率最大的资源块分配给信道增益最大的用户,从而在满足用户业务需求的前提下提高小区吞吐量。仿真结果表明,该算法优于传统的SSA(separate and sequential allocation)算法,系统整体性能得到提升。

一种柔性路径下的跨单元调度方法

针对单元制造系统(Cellular manufacturing system,CMS)中需要多个单元协作完成的特殊工件,提出柔性路径下跨作业(Job shop)单元的特殊工件调度方法—基于信息素的方法(Pheromone-based approach,PBA).基于多Agent对单元制造系统建立模型,提出了冗余单元的概念,建立了多Agent之间的协商机制.同时通过建立Agent联盟,减少通信量的同时增强系统的鲁棒性和调度优化的全局性.实验结果表明,与常见的组合调度规则相比,本文提出的方法在5种性能指标上具有显著优势.

LTE系统自适应软频率复用技术研究

提高小区边缘用户性能是蜂窝移动通信系统的经典难题.下一代蜂窝移动通信系统3GPP LTE通过有效的小区间干扰协调以及频率资源分配来改善小区边缘用户性能.提出一种自适应软频率复用算法,根据系统负载情况自适应地为各小区分配主、副载波及其发射功率,在实现系统吞吐量优化的同时保证小区中心和边缘区域速率需求.算法首先通过穷尽搜索和贪婪递减策略,获得单小区最优资源分配,然后在不同小区间迭代执行单小区算法直到系统吞吐量不变为止.仿真结果表明,算法通过多次迭代后,系统吞吐量保持不变并输出一种优化的资源分配方案.与同类频率分配算法相比,可以有效提升小区边缘用户的吞吐量,同时获得更高的系统容量,更适用于高速率的LTE系统.

一种基于动态决策块的超启发式跨单元调度方法

对运输能力受限条件下的跨单元调度问题进行分析,提出一种基于动态决策块和蚁群优化(Ant colony optimization,ACO)的超启发式方法,同时解决跨单元生产调度和运输调度问题.在传统超启发式方法的基础上,采用动态决策块策略,通过蚁群算法合理划分决策块,并为决策块选择合适的规则.实验表明,采用动态决策块策略的超启发式方法比传统的超启发式方法具有更好的性能,本文所提的方法在最小化加权延迟总和目标方面有较好的优化能力并且具有较高的计算效率.