Generation of optimal persistent formations for heterogeneous multi-agent systems with a leader constraint

In this study, we consider the generation of optimal persistent formations for heterogeneous multi-agent systems, with the leader constraint that only specific agents can act as leaders. We analyze three modes to control the optimal persistent formations in two-dimensional space, thereby establishing a model for their constrained generation. Then, we propose an algorithm for generating the optimal persistent formation for heterogeneous multi-agent systems with a leader constraint （LC-HMAS-OPFGA）, which is the exact solution algorithm of the model, and we theoretically prove its validity. This algorithm includes two kernel sub-algorithms, which are optimal persistent graph generating algorithm based on a minimum cost arborescence and the shortest path （MCA-SP-OPGGA）, and the optimal persistent graph adjusting algorithm based on the shortest path （SP-OPGAA）. Under a given agent formation shape and leader constraint, LC-HMAS-OPFGA first generates the network topology and its optimal rigid graph corresponding to this formation shape. Then, LC-HMAS- OPFGA uses MCA-SP-OPGGA to direct the optimal rigid graph to generate the optimal persistent graph. Finally, LC- HMAS-OPFGA uses SP-OPGAA to adjust the optimal persistent graph until it satisfies the leader constraint. We also demonstrate the algorithm, LC-HMAS-OPFGA, with an example and verify its effectiveness.

Cooperative task allocation for heterogeneous multi-UAV using multi-objective optimization algorithm

The application of multiple UAVs in complicated tasks has been widely explored in recent years.Due to the advantages of flexibility,cheapness and consistence,the performance of heterogeneous multi-UAVs with proper cooperative task allocation is superior to over the single UAV.Accordingly,several constraints should be satisfied to realize the efficient cooperation,such as special time-window,variant equipment,specified execution sequence.Hence,a proper task allocation in UAVs is the crucial point for the final success.The task allocation problem of the heterogeneous UAVs can be formulated as a multi-objective optimization problem coupled with the UAV dynamics.To this end,a multi-layer encoding strategy and a constraint scheduling method are designed to handle the critical logical and physical constraints.In addition,four optimization objectives:completion time,target reward,UAV damage,and total range,are introduced to evaluate various allocation plans.Subsequently,to efficiently solve the multi-objective optimization problem,an improved multi-objective quantum-behaved particle swarm optimization(IMOQPSO)algorithm is proposed.During this algorithm,a modified solution evaluation method is designed to guide algorithmic evolution;both the convergence and distribution of particles are considered comprehensively;and boundary solutions which may produce some special allocation plans are preserved.Moreover,adaptive parameter control and mixed update mechanism are also introduced in this algorithm.Finally,both the proposed model and algorithm are verified by simulation experiments.

Yielding and fracture behaviors of coarse-grain/ultrafine-grain heterogeneous-structured copper with transitional interface

Heterogeneous-structured Cu samples composed of coarse-grained(CG) and ultrafine-grained(UFG) domains with a transitional interface were fabricated by friction stir processing, in order to investigate the effect of interface constraint on the yielding and fracture behaviors. Tensile test revealed that the synergetic strengthening induced by elastic/plastic interaction between incompatible domains increases with increasing the area of constraint interface. The strain distribution near interface and the fracture morphology were characterized using digital image correlation technique and scanning electron microscopy, respectively. Fracture dimples preferentially formed at the interface, possibly due to extremely high triaxial stress and strain accumulation near the interface. Surprisingly, the CG domain was fractured by pure shear instead of the expected voids growth caused by tensile stress.

A trajectory shaping guidance law with field-of-view angle constraint and terminal limits

In this paper, a trajectory shaping guidance law,which considers constraints of field-of-view(FOV) angle, impact angle, and terminal lateral acceleration, is proposed for a constant speed missile against a stationary target. First, to decouple constraints of the FOV angle and the terminal lateral acceleration, the third-order polynomial with respect to the line-ofsight(LOS) angle is introduced. Based on an analysis of the relationship between the looking angle and the guidance coefficient,the boundary of the coefficient that satisfies the FOV constraint is obtained. The terminal guidance law coefficient is used to guarantee the convergence of the terminal conditions. Furthermore, the proposed law can be implemented under bearingsonly information, as the guidance command does not involve the relative range and the LOS angle rate. Finally, numerical simulations are performed based on a kinematic vehicle model to verify the effectiveness of the guidance law. Overall, the work offers an easily implementable guidance law with closed-form guidance gains, which is suitable for engineering applications.

Impact of product heterogeneity and soft budget constraint on excess capacity in Chinese energy industry based on the duopoly model

Chinese energy industries are facing serious problems such as excess capacity,homogeneous product,and soft budget constraint.This paper provides a duopoly model to investigate the influence of heterogeneity and soft budget constraint on production capacity decision and internal action mechanism,respectively,under Cournot and Bertrand competitions,which reveals the formation mechanism of excess capacity.We conclude that excess capacity would exist when the products are not wholly heterogeneous under Cournot competition,and the higher level of the soft budget constraint or the more homogeneous the products are,the worse the excess capacity will be.The insufficient capacity would exist provided that products are not wholly heterogeneous under Bertrand competition,and the higher level of soft budget constraint or the more homogeneous the products are,the more insufficient capacity will be.Both soft budget constraint and product heterogeneity mutually affect to decision-making of capacity and output.

战术网络中基于资源负载均衡和服务优先级的业务调度策略

针对战术网络环境的多样化业务和网络异构性、高动态特性导致的网络负载易失衡的问题,提出了一种基于资源负载均衡和服务优先级的业务调度策略。通过所承载业务类型的优先级感知,基于通信网络当时可用资源等约束,将业务按需调度到战术通信网络的通信资源池,达到通信网络的自动负载均衡和资源可靠合理利用,提高业务服务质量,并保证高优先级业务可靠传输。通过仿真,验证了该策略算法可大大提高网络吞吐量和资源利用效率。

数字化转型与企业新质生产力水平

本文选取2011~2022年我国A股上市公司年度数据为研究样本,考察数字化转型对企业新质生产力水平的影响,并探究两者之间的作用机制和异质性因素。实证发现:数字化转型能够显著提高企业新质生产力水平,机制检验表明数字化转型通过缓解资金约束、强化管理者能力和提高信息透明度,促进企业新质生产力水平上升。异质性分析显示,国有企业、技术密集型企业和处于数字基础设施水平较弱地区的企业,实施数字化转型对新质生产力水平的提升作用更为明显。本文结论为制定推进企业数字化转型和新质生产力建设的相关政策提供了有益参考。

异质机构投资者持股对企业ESG表现的影响研究

以2011—2021年A股上市公司为研究样本,分析了异质机构投资者持股对于企业ESG表现的影响,并进一步检验了压力抵抗型机构投资者的作用机制。研究发现,压力抵抗型机构投资者更能够显著提升企业的ESG表现,并且在非国有企业、高新技术企业中这种促进作用更强;进一步机制检验表明,压力抵抗机构投资者可以通过缓解企业融资约束、提升企业内部控制水平的作用渠道对企业ESG表现产生促进作用。

预算软约束对地区经济增长的影响及其门槛效应研究

在内外需求日益疲软以及地方债务规模较大的情况下,我国推出了一系列积极的财政措施,这要求政府增加举债规模。本研究从全国范围和东、中、西部地区出发,使用基准回归模型和门槛效应模型对地方政府预算软约束对经济增长的影响进行了实证检验。研究发现,地方政府财政预算软约束显著阻碍了地区经济增长,且二者之间存在显著的门槛效应。异质性分析表明,地方政府预算软约束对经济增长的负向作用会受到区域差异的影响。因此,地方政府应采取优化转移支付制度、促进融资平台的市场化转型、完善过度负债约束机制、转变官员政绩考核理念、因地制宜地制定差异性防范政策等措施稳定地区经济增长。

生态文明建设示范区对企业全要素生产率的影响研究——基于财政分权视角

生态文明建设示范区是中国政府推进生态文明建设的一项制度创新。本文以2011~2022年沪深A股制造业上市公司为研究样本,采用多期双重差分模型实证探究生态文明建设示范区对企业全要素生产率的影响。研究发现:(1)生态文明建设示范区提升了企业全要素生产率,且这一结果在经过一系列稳健性检验后仍然成立;(2)生态文明建设示范区对企业全要素生产率的促进作用随着财政分权程度的提高而降低;(3)进一步分析表明,生态文明建设示范区对企业全要素生产率的促进作用在非国有企业、东部企业和大规模企业中更显著。生态文明建设示范区主要是通过缓解企业面临的融资约束来促进企业全要素生产率的提升。本文的研究对于全面建设生态文明、促进企业转型、提升企业全要素生产率和经济的高质量发展具有一定的参考意义。

罕见灾难风险对小微企业冲击和影响分析:基于厂商异质性融资约束的DSGE模型

本文在新凯恩斯框架的DSGE模型中引入了劳动供给意愿和资本开工率的冲击,以反映罕见灾难发生导致的居民复工意愿下降和企业停工风险对经济发展,以及小微和大中型企业生产经营的异质性影响。模型的分析结果表明,在没有政策干预的情况下,罕见灾难冲击会导致总投资减少,失业率增加,通货膨胀上升,使得经济出现较大的下行压力。相较于大中型企业,具有融资约束的小微企业受灾难冲击的负面影响更大。本文从缓解小微企业融资约束和执行宽松货币政策着手,探讨了不同强度的救助措施对促进经济恢复的效果。小微企业融资约束的减弱可以增加社会总投资和就业。宽松的货币政策有助于对冲罕见灾难的负面影响,但不具备长期增长效应。本文从理论上分析了罕见灾难发生后国家和地方政府加大对小微企业的扶持力度的必要性和紧迫性。

设立产业转型升级示范区对企业融资约束的影响——基于交错双重差分模型

本文以产业转型升级示范区设立作为准自然实验,利用2010-2019年中国A股上市公司数据,采用交错双重差分模型考察了示范区政策对企业融资约束的影响及作用路径,并充分探讨了交错双重差分模型的处理效应异质性。研究发现,示范区设立以后,能够显著缓解辖区内企业的融资约束,并且政策效果具有持续性,上述结论在考虑交错双重差分模型的处理效应异质性以及一系列识别假定检验和稳健性检验后依然成立。机制分析表明,扩大企业融资来源和降低企业经营成本是示范区政策缓解企业融资约束的重要途径。宏观层面加强政府调节,坚持市场导向,进一步扩大开放,能够有效吸引金融机构和投资者参与示范区建设,助力示范区企业资金融通,对缓解示范区企业的融资约束具有积极作用。此外,示范区政策的实施,为企业发展创造了良好的营商环境,吸引大量新企业入驻,激发了企业创新转型发展的内生动力,提升了企业的全要素生产率水平,具有显著的经济效益。本文的结论有助于拓展宏观产业政策与企业行为的研究框架,对进一步完善示范区政策具有重要启示。

数字普惠金融、融资约束与中小企业投资效率

通过构建异质性随机前沿模型,利用北京大学数字普惠金融指数市级数据和上市公司财务数据,探究数字普惠金融对中小企业融资约束和融资不确定性的作用,从而估算出投资效率。研究发现:我国中小企业在投资时面临显著的融资约束,融资约束的存在使得实际投资水平比最优投资水平低了30%-40%,平均投资效率仅为64%,且投资效率存在明显的异质性特征。数字普惠金融的发展能缓解中小企业融资约束,提高投资效率,这一作用在东部地区和非国有企业样本中更加显著。但是,数字普惠金融的发展同时也增加了中小企业的融资不确定性,加剧了金融市场风险。研究为数字普惠金融的发展缓解中小企业融资约束,提升投资效率提供了经验证据,为如何更好地发挥金融市场对中小企业的支持作用,促进经济高质量发展提供了理论依据和政策启示。

数字金融对企业技术创新的作用机制及其异质性检验

为促进企业技术创新,本文以2012~2022年我国A股上市企业为研究对象,开展了数字金融对企业技术创新的作用机制及其异质性检验实证研究。具体地,运用研究对象的面板数据进行回归,以企业技术创新为被解释变量,数字金融为解释变量,企业数字化程度为调节变量,融资约束和融资成本为中介变量,企业规模、企业盈利能力、企业年限、企业成长性、高管激励、股权集中度、董事会独立性为控制变量,通过回归分析、调节作用检验、中介效应检验、异质性检验和稳健性分析,验证了被解释变量和解释变量之间的相关性。结果表明,数字金融促进企业技术创新,且对数字化程度高的企业技术创新促进作用更强;数字金融通过缓解企业融资约束、降低企业融资成本来促进企业技术创新;数字金融对非国有企业、高技术行业和成熟期企业的技术创新促进作用更显著。在此基础上,为进一步提高企业技术创新,分别从政府层面、金融监管部门层面和企业层面,提出了针对性建议与政策,以充分发挥数字金融对企业技术创新的促进作用。

企业ESG表现、融资约束与绿色创新绩效

以2017—2021年我国A股上市企业为研究样本,对其ESG表现与绿色创新绩效间的关系进行控制固定效应面板模型的实证研究,并通过中介效应模型检验融资约束在上述关系中的作用机制.研究结果表明,企业ESG表现及其3个维度(环境、社会、治理)均对绿色创新绩效有促进作用;融资约束在企业ESG表现与绿色创新绩效的关系中存在中介作用.上述结论在被解释变量被替换、滞后以后仍成立.此外,在异质性分析中发现,相较于非国有企业及中西部地区企业,国有企业及东部地区的企业ESG表现对绿色创新绩效的促进效用更明显.

考虑物品异质性的联合补货-配送集成优化模型与智能求解算法

多物品联合补货策略通过协调不同物品的补货周期实现规模效益,可以有效降低物流成本。在多物品联合补货系统中,物品异质性是一个难以忽视的问题。物品异质性常常导致物品损坏、质量损失、运输风险等问题。针对这一现象,构建一种考虑资源约束的异质品联合补货-配送模型。为求解该NP-hard问题,设计一种基于自适应重组与反向学习策略的骨干差分进化算法。实验结果表明,新算法在运算时间和运算精度上比几种对比算法都有明显提升;算法表现与主要订货成本存在明显相关性,将该参数引入自适应重组策略有望进一步改进算法性能。

A GMM approach in coupling internal data and external summary information with heterogeneous data populations

Because of advances in data collection and storage,statistical analysis in modern scientific research and practice now has opportunities to utilize external information such as summary statistics from similar studies.A likelihood approach based on a parametric model assumption has been developed in the literature to utilize external summary information when the populations for external and main internal data are assumed to be the same.In this article,we instead consider the generalized estimation equation(GEE)approach for statistical inference,which is semiparametric or nonparametric,and show how to utilize external summary information even when internal and external data populations are not the same.Our approach is coupling the internal data and external summary information to form additional estimation equations and then applying the generalized method of moments(GMM).We show that the proposed GMM estimator is asymptotically normal and,under some conditions,is more efficient than the GEE estimator without using external summary information.Estimators of the asymptotic covariance matrix of the GMM estimators are also proposed.Simulation results are obtained to confirm our theory and quantify the improvements by utilizing external data.An example is also included for illustration.

带有非一致约束和通讯时延的异构网络约束一致性

本文主要致力于研究一类具有非一致的凸位置约束、非凸速度约束和非一致的通信时延的异构多智能体网络的约束一致性问题,其中异构多智能体网络由一阶和二阶智能体构成.首先,为每个智能体设计了一个分布式控制算法,同时,引入了两类坐标变换,将带有时延的异构系统转化为带有异构非线性误差和无时延的线性时变系统.为了处理异构非线性误差,本文采用了一种几何学技巧,使组合变量的非线性动态可以被线性动态所控制.然后,通过投影算子和非负矩阵的性质,在一些弱的假设下,证明了随着时间的演进,非线性误差能收敛为零,从而达成系统的受限一致性.最后,本文给出两个数值算例验证了结果的正确性.

债务来源异质性会抑制企业超额现金持有水平吗?

以2009—2021年A股上市企业为样本,探讨债务来源异质性对企业超额现金持有水平的影响。研究发现:债务来源异质性显著降低了企业超额现金持有水平,且经过一系列稳健性检验后,上述结论依然成立。作用机理分析发现:债务来源异质性能够通过降低代理成本和缓解融资约束显著降低企业超额现金持有水平。异质性分析发现:债务来源异质性对企业超额现金持有水平的降低作用在市场竞争程度较低的地区、国有企业以及小规模企业中更明显;而机构投资者持股比例较高、媒体关注度较高、内部控制质量较高会削弱债务来源异质性对超额现金持有水平的抑制作用。经济后果研究发现:超额现金持有降低了企业的可持续发展能力,而债务来源异质性能够削弱这种消极影响。研究结论为充分发挥债务治理作用,提高企业资金配置效率提供了重要依据。

宏观经济环境对企业融资决策的动态影响研究

本文从总体视角研究了我国宏观经济环境变化对于企业融资决策的动态影响,从个体视角研究了这一影响的作用机制,进一步探讨了地区金融发展水平和融资约束带来的影响差异。研究结果表明:从总体视角,在宏观经济环境变化的恢复阶段,企业偏好内部融资;在扩张阶段,企业偏好债权融资;在衰退阶段,企业偏好股权融资;在紧缩阶段,企业偏好短期债权融资。从个体视角,宏观经济环境会通过影响企业的托宾Q和内部现金流来影响企业的债权和股权融资。宏观经济环境对于企业融资决策的影响也会因地区金融发展水平和融资约束的不同存在差异。本文提出,建立多层次的股票市场和债券市场、采取精准匹配的信贷政策、推出更多直达实体经济的货币政策工具对于推动金融供给侧结构性改革、支持实体经济高质量发展具有十分重要的意义。