Influence of the Agreement on Enhancing International Arctic Scientific Cooperation on the approach of non-Arctic states to Arctic scientific activities

As the third legally-binding instrument of the Arctic Council, the Agreement on Enhancing International Arctic Scientific Cooperation was signed in May 2017 and entered into force on 23 May 2018. The Agreement not only reduces obstacles to the international scientific cooperation and promotes the movement of people and equipment across borders for the effective and efficient development of Arctic scientific knowledge, but also provides an improved international Arctic legal environment for conducting Arctic scientific cooperation based on UNCLOS and institutional arrangements. However, the observer states, the NGOs and IGOs, as well as Permanent Participants are rarely mentioned in this Agreement. This article chooses one group, non-Arctic states, as a case in point in order to critically discuss the influence of this new Arctic scientific cooperation agreement. It argues that the non-Arctic states are left behind at the original legal situation and trapped in an inferior status in Arctic science. Under these circumstances, this article suggests that non-Arctic states, especially those with competitive research abilities, should appeal for amendment of the Agreement to allow wider access to research areas and data sharing, especially when cooperating with the eight-member states of the Arctic Council. Also, non-Arctic states should take the Agreement as the reference when signing bilateral agreements with Arctic states so as to safeguard their interests when conducting Arctic scientific activities. Moreover, the active participation in other fora as well as various bilateral scientific projects can assist non-Arctic states to strengthen the relations with the Arctic states and build trust in the Arctic Council.

反向散射NOMA赋能的混合多播-单播协作传输方案

针对协作中继通信系统频谱效率低和链路利用率低的问题,面向多播、单播业务共存场景,该文提出一种反向散射NOMA赋能的混合多播-单播协作传输方案。机会式选择一个多播用户作为协作节点,将其接收信号的一部分功率用于自身解码,剩余功率反向散射以增强其余用户的接收质量。为提升系统性能,通过联合优化基站功率分配系数、协作用户反向散射系数和协作节点选择变量,在保障多播服务质量的前提下,实现单播用户最小可达速率的最大化。为解决上述高度非凸联合优化问题,该文设计一种协作用户选择准则并提出了一种迭代算法来获取原问题的最优解。仿真结果验证了所提迭代算法的快速收敛性,相较于传统非协作传输方案,所提方案可将单播用户最小可达速率提升11.5%,有效保证多业务服务质量。

博弈视角下电-气互联综合能源系统多目标协同优化

考虑到现有综合能源系统多目标优化存在主观性,文中提出一种基于非合作博弈理论的单主体多目标协同优化方法。首先,建立耦合配电网络、配气网络和能源站的电-气互联综合能源系统模型。为使优化调度结果更贴近现实,在配气网模型中采用可变压缩比的压缩机模型,并考虑其非线性耗量特性。其次,基于非合作博弈理论,将能源站单一利益主体的经济性目标和环保性目标视为完全平等且理性的虚拟博弈者,其策略空间由系统内各设备约束组成。再次,为确保博弈模型存在纳什均衡解,在新增辅助变量和约束作用下将收益函数(目标函数)转为拟凸的可微函数。采用凸松弛方法处理模型中非凸非线性约束,并提出非线性迭代策略加速松弛收紧。为便于求解出纳什均衡,使用Nikaido-Isoda函数重构收益函数,将原模型转变为全局最优问题。最后,通过算例验证了所提方法的有效性。

Game theoretic analysis for pricing-based incentive mechanism in non-dedicated cooperative relay networks

In non-dedicated cooperative relay networks, each node is autonomous and selfish in nature, and thus spontaneous cooperation among nodes is challenged. To stimulate the selfish node to participate in cooperation, a pricing-based cooperation engine using game theory was designed. Firstly, the feasible regions of the charge price and reimbursement price were deduced. Then, the non-cooperative and cooperative games were adopted to analyze the amount of bandwidth that initiating cooperation node(ICN) forwards data through participating cooperation node(PCN) and the amount of bandwidth that PCN helps ICN to relay data. Meanwhile, the Nash equilibrium solutions of cooperation bandwidth allocations(CBAs) were obtained through geometrical interpretation. Secondly, a pricing-based cooperation engine was proposed and a cooperative communication system model with cooperation engines was depicted. Finally, an algorithm based on game theory was proposed to realize the cooperation engine. The simulation results demonstrate that, compared with the system without pricing-based incentive, the proposed system can significantly improve the ICN's metric measured by bit-per-Joule and increase the PCN's revenue.

Design of a Non-cooperative Target Capture Mechanism

A passive compliant non-cooperative target capture mechanism is designed to maintain the non-cooperative target on-orbit. When the relative position between capture mechanism and satellite is confirmed,a pair of four-bar linkages lock the docking ring,which is used for connecting the satellite and the rocket. The mathematical model of capture mechanism and capture space is built by the Denavit-Hartenberg(D-H)method,and the torque of each joint is analyzed by the Lagrange dynamic equation. Besides,the capture condition and the torque of every joint under different capture conditions are analyzed by simulation in MSC. Adams. The results indicate that the mechanism can capture the non-cooperative target satellite in a wide range. During the process of capture,the passive compliant mechanism at the bottom can increase capture space,thereby reducing the difficulty and enhance stability of the capture.

基于Lyapunov-MPC方法的非合作目标近距离抵近控制

针对航天器近距离视线抵近同时存在轨道与姿态机动的非合作目标特定方位控制问题,提出了一种基于控制Lyapunov函数(CLF)的模型预测控制方法 (LMPC)。首先,根据视线坐标系下的轨道动力学方程,建立了满足视线指向要求的航天器相对轨道动力学模型,并推导了期望轨道的解析表达式。其次,利用MPC方法设计控制器进行在线优化控制,并通过纳入基于李雅普洛夫方法的非线性反步控制的显式特征,构建收缩约束式,以确保闭环稳定性。接着,对基于LMPC的控制方法的递归可行性和闭环稳定性进行了证明。最后,仿真结果证明了所设计的LMPC轨迹跟踪方法的有效性和鲁棒性。

基于N-EKF的非合作低轨目标双星无源定位跟踪算法

针对两颗天基光学卫星对低轨非合作目标进行无源定位跟踪的问题,提出了一种基于Newton迭代与扩展卡尔曼滤波(Newton iteration and extended Kalman filter,N-EKF)的定位跟踪算法。首先,将基于角度测量信息的双星观测模型转化为双直线公垂线中点问题,并进一步转化为非线性方程问题,使用Newton迭代算法得到非合作目标的初始定位信息。然后,采用扩展卡尔曼滤波(extended Kalman filter,EKF)方法,在初始定位信息基础上,结合近地轨道动力学模型,实现对非合作在轨目标的精确跟踪滤波。最后,通过仿真验证了所提方法的可行性及优势。

基于DB-YOLO的双基地雷达弱运动目标检测方法

非合作双基地雷达因其特殊的探测方式,致使回波中目标信噪比较低,特别是海上运动目标,在雷达扫描周期的帧与帧之间探测并不稳定,会对后续目标跟踪造成较大困难。本文首先采用低门限恒虚警率(CFAR)检测器将雷达距离-多普勒维和距离-方位维的检测结果匹配,得到相应掩码图,筛选出潜在的运动目标;然后提出一种融合多维特征信息的双主干YOLO(DB-YOLO),该网络采用双主干结构,同时提取动目标掩码图和其映射下相同尺度P显图的特征,并采用深度可分离卷积模块降低网络的模型参数。将该模型与Faster RCNN、YOLOv5及其常见变种YOLOv5-ConvNeXt进行对比,实验表明,DB-YOLO有效提高了目标检测性能并保证了推理速度,为非合作双基地雷达的目标跟踪奠定了基础。

Non-cooperative game for network access selection in heterogeneous integrated networks

The integration of different heterogeneous access networks is one of the remarkable characteristics of the next generation network,in which users with multi-network interface terminals can independently select access network to obtain the most desired service.A kind of unified quantification model of non-monotone quality of service(QoS) and a model of non-cooperative game between users and networks are proposed for heterogeneous network access selection.An optimal network pricing mechanism could be formulated by using a novel strategy which is used in this non-cooperative game model to balance the interests of both the users and the networks.This access network selection mechanism could select the most suitable network for users,and it also could provide the basis when formulating QoS standards in heterogeneous integrated networks.The simulation results show that this network selection decision-making algorithm can meet the users' demand for different levels service in different scenes and it can also avoid network congestion caused by unbalanced load.

QoS awared power and admission controls based on non-cooperative game theory in wireless networks

In order to better accommodate heterogeneous quality of service (QoS) in wireless networks, an algorithm called QoS-aware power and admission controls (QAPAC) is proposed. The system is modeled as a non-cooperative game where the users adjust their transmit powers to maximize the utility, thus restraining the interferences. By using adaptive utility functions and tunable pricing parameters according to QoS levels, this algorithm can well meet different QoS requirements and improve system capacity compared with those that ignore the QoS differences.

Removal of jamming using independent component analysis in non-cooperative passive detection system

Due to electronic jamming transmitted by hostile electronic jamming equipments and unintentional jamming from other illuminating sources in the complex electromagnetic environment,the performance of non-cooperative passive detection systems may degrade it significantly.To solve the problem,a receiving frame with multiple channels for signal preprocessing is designed and a theoretical analysis to the received signals in the complex electromagnetic environment is provided.Furthermore,a scheme for jamming removal using independent component analysis is proposed.Simulation results demonstrate the proposed scheme appears as a very appealing solution for removal of jamming and an approximate 10 dB signal to distortion ratio over traditional schemes is obtained.

Cause Analysis of "Non-agricultural Trend" of Credit Cooperatives and Reversion Approaches

"Non-agricultural trend" of credit cooperatives is demonstrated as outflow of substantial contribution, application of credit fund in "non-agricultural sectors" and downsizing outlets. As a result, rural financial exclusion and insufficient effective supply of rural finance have been aggravated, and most rural households have been excluded from the service range of credit cooperatives. Major causes for such a trend were summarized as: (a) profit-driven nature of credit cooperatives; (b) conditionality of "agriculture, rural area and peasant" economy; (c) influence of macro-environment. It is proposed that credit cooperatives would only revert their focus to "agriculture, rural area and peasant" economy only if rural financial exclusion and economic restrictions on the development of credit cooperatives were removed, and the macro-environment was optimized.

Multi-Feature Fusion Based Relative Pose Adaptive Estimation for On-Orbit Servicing of Non-Cooperative Spacecraft

On-orbit servicing, such as spacecraft maintenance, on-orbit assembly, refueling, and de-orbiting, can reduce the cost of space missions, improve the performance of spacecraft, and extend its life span. The relative state between the servicing and target spacecraft is vital for on-orbit servicing missions, especially the final approaching stage. The major challenge of this stage is that the observed features of the target are incomplete or are constantly changing due to the short distance and limited Field of View (FOV) of camera. Different from cooperative spacecraft, non-cooperative target does not have artificial feature markers. Therefore, contour features, including triangle supports of solar array, docking ring, and corner points of the spacecraft body, are used as the measuring features. To overcome the drawback of FOV limitation and imaging ambiguity of the camera, a "selfie stick" structure and a self-calibration strategy were implemented, ensuring that part of the contour features could be observed precisely when the two spacecraft approached each other. The observed features were constantly changing as the relative distance shortened. It was difficult to build a unified measurement model for different types of features, including points, line segments, and circle. Therefore, dual quaternion was implemented to model the relative dynamics and measuring features. With the consideration of state uncertainty of the target, a fuzzy adaptive strong tracking filter( FASTF) combining fuzzy logic adaptive controller (FLAC) with strong tracking filter(STF) was designed to robustly estimate the relative states between the servicing spacecraft and the target. Finally, the effectiveness of the strategy was verified by mathematical simulation. The achievement of this research provides a theoretical and technical foundation for future on-orbit servicing missions.

Non-professional Agricultural Production Villages Establishing a New Rural Cooperative

The article analyzes problems in the agricultural development of non-professional agricultural production villages of Fenghua City.Firstly,low technical and scientific content of production and low standardization level.Secondly,scattered sales and non-fixed marketing channels.Thirdly,difficulties in group cooperation of farm crops with special benefits.Fourthly,imperfect service of rural committees of non-professional agricultural production villages in Fenghua City.A new rural cooperative is to be founded to help villagers in non-professional agricultural production villages of Fenghua City to be engaged in agricultural production and management activities,and to improve their overall incomes.On the one hand,a perfect and scientific cooperative operating system is to be built specifically including three functions.Firstly,fully playing the leading and bridging role of rural primary organizations.Secondly,fully carrying out the pushing role of capable persons in the administrative village.Lastly,fully playing the role of active participation and cooperation of villagers.On the other hand,constructions of normalization,standardization and brand orientation with special emphasis should be achieved under the guidance of local governments.The key of building a cooperative of non-professional agricultural production villages in Fenghua City is discussed.One is that rural cadres should have strong awareness of serving the people.The other is that governments at all levels should energetically support the establishment and management of rural cooperatives.

A Method to Obtain the Moving Speed of Uncooperative Target Based on Only Two Measurements

The existing research results show that a fixed single station must conduct three consecutive frequency shift measurements and obtain the target’s moving speed by constructing two frequency difference equations. This article proposes a new method that requires only two consecutive measurements. While using the azimuth measurement to obtain the angular difference between two radial distances, it also conducts two consecutive Doppler frequency shift measurements at the same target azimuth. On the basis of this measurement, a frequency difference equation is first constructed and solved jointly with the Doppler frequency shift equation. By eliminating the velocity variable and using the measured angular difference to obtain the target’s lead angle, the target’s velocity can be solved by using the Doppler frequency shift equation again. The new method avoids the condition that the target must move equidistantly, which not only provides an achievable method for engineering applications but also lays a good foundation for further exploring the use of steady-state signals to achieve passive positioning.

肥胖儿童non-HDL-C、remnant cholesterol与亚临床动脉粥样硬化的关系

目的:了解non-HDL-C和remnant cholesterol与肥胖儿童亚临床动脉粥样硬化(AS)的关系。方法:根据甘油三酯(TG)水平将65例肥胖儿童(肥胖组)分为I组(TG≥2.3 mmol/L)32例,II组(TG<2.3 mmol/L)33例,与肥胖组儿童性别年龄相匹配的正常体质量儿童30例为III组(对照组)。比较3组儿童血脂指标,对肥胖组各项血脂指标与血浆致动脉粥样硬化指数(AIP)进行相关性分析,肥胖患儿体质指数、血脂指标与颈动脉内径、内膜-中层厚度(c-IMT)、血流参数进行相关性分析。结果:I组、II组的TG、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、non-HDL-C、remnant cholesterol、AIP均较对照组升高,高密度脂蛋白胆固醇(HDL-C)较对照组降低,且I组的remnant cholesterol、AIP均较II组升高。肥胖组儿童AIP与TG、non-HDL-C、remnant cholesterol呈正相关,与HDL-C呈负相关。37例行颈动脉超声检查的肥胖儿童的c-IMT较正常儿童的增厚。结论:non-HDL-C、remnant cholesterol在肥胖儿童亚临床AS中有重要作用,在肥胖儿童血脂异常的治疗中应关注non-HDL-C、remnant cholesterol的变化。

基于α-CIS值的非合作-合作双型博弈的求解

本文研究了非合作-合作双型博弈模型求解的问题.首先利用于α-CIS值,求解非合作-合作双型博弈中的合作博弈阶段,再对非合作博弈阶段求其纯策略纳什均衡,获得了基于α-CIS值的双型博弈的一种新的求解方法.推广了原始双型博弈模型的求解方法并证明其可行性.

Non-contact angle measurement based on parallel multiplex laser feedback interferometry

We present a novel precise angle measurement scheme based on parallel multiplex laser feedback interferometry （PLFI）, which outputs two parallel laser beams and thus their displacement difference reflects the angle variation of the target. Due to its ultrahigh sensitivity to the feedback light, PLFI realizes the direct non-contact measurement of non- cooperative targets. Experimental results show that PLFI has an accuracy of 8＂ within a range of 1400＂. The yaw of a guide is also measured and the experimental results agree with those of the dual-frequency laser interferometer Agilent 5529A.