期刊文献+
共找到78,036篇文章
< 1 2 250 >
每页显示 20 50 100
Corporate Social Responsibility and Green Innovation-The Mediating Effect of Financing Constraints
1
作者 SONG Xiaowen YANG Cunbo ZHAO Mengqi 《Journal of Modern Accounting and Auditing》 2023年第2期36-52,共17页
Green innovation has become a strategic direction for the country and enterprises,and it is an important facet in achieving high-quality economic development.Whether corporate social responsibility(CSR),as a key compe... Green innovation has become a strategic direction for the country and enterprises,and it is an important facet in achieving high-quality economic development.Whether corporate social responsibility(CSR),as a key competitive strategy for achieving sustainable economic development,can promote corporate green innovation and the path of evolution has become a hot topic of current research.This paper takes Chinese manufacturing A share listed companies as its sample and uses Stata sofware to conduct regression analysis to test the relationship between CSR,financing constraints,and green innovation,respectively.It further distinguishes the sample into different technological properties and different regions to study the degree of differentiation of the mediating effect on financing constraints.The results show that CSR can not only directly promote corporate green innovation,but that it also can further positively influence corporate green innovation by alleviating financing constraints.Financing constraints play a mediating role in the relationship between CSR and green innovation,especially in enterprises with strong innovation demand and in regions with high levels of regional economic development.The findings enrich the research perspective on the relationship between CSR and green innovation and provide realistic data support for subsequent studies. 展开更多
关键词 corporate social responsibility fnancing constraints green inovation stakeholder theory signaling theory
下载PDF
An Empirical Study on CEO’s Academic Experience and Financing Constraints-Taking Shanghai and Shenzhen A-Share Listed Companies as Samples
2
作者 Qirun Zhang Xuan Liu 《Management Studies》 2021年第4期270-279,共10页
Taking A-share listed companies in Shanghai and Shenzhen from 2007 to 2018 as samples,this paper analyzes the influence of CEO’s academic experience on corporate financing constraints.The empirical results show that ... Taking A-share listed companies in Shanghai and Shenzhen from 2007 to 2018 as samples,this paper analyzes the influence of CEO’s academic experience on corporate financing constraints.The empirical results show that there is a negative correlation between CEO’s academic experience and enterprise financing constraint level.Compared with state-owned enterprises,the academic experience of CEO in private enterprises is significantly negatively correlated with the level of corporate financing constraints.It also suggests that CEO’s academic experience can significantly reduce the level of financing constraints in the company samples audited by accounting firms(not Big 4).The conclusion of this paper is helpful to enrich the research of manager characteristics and corporate governance.At the same time,the research in this paper has reference significance for enterprises to ease the level of financing constraints. 展开更多
关键词 CEO academic experience enterprise financing constraints nature of property rights big four audit firms
下载PDF
Financing constraints and corporate investment:an empirical analysis of china’s manufacturing firms
3
作者 孔煜 《Journal of Chongqing University》 CAS 2005年第3期170-174,共5页
With the measurement of dividend payout ratio, logistic regression index value and the firm size financing constraints, this paper investigated the investment behavior of China’s manufacturing firms over the period f... With the measurement of dividend payout ratio, logistic regression index value and the firm size financing constraints, this paper investigated the investment behavior of China’s manufacturing firms over the period from 1998 to 2003, and the relationship between financing constraints and corporate investment using the OLS regression method. The empirical evidence shows that there are certain extent financing constraints in China’s manufacturing firms, but the results are different with different variables to measure the financing constraints. 展开更多
关键词 融资约束 社团投资 中国 制造业 投资策略
下载PDF
Adaptive H_(∞)Filtering Algorithm for Train Positioning Based on Prior Combination Constraints
4
作者 Xiuhui Diao Pengfei Wang +2 位作者 Weidong Li Xianwu Chu Yunming Wang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第2期1795-1812,共18页
To solve the problem of data fusion for prior information such as track information and train status in train positioning,an adaptive H∞filtering algorithm with combination constraint is proposed,which fuses prior in... To solve the problem of data fusion for prior information such as track information and train status in train positioning,an adaptive H∞filtering algorithm with combination constraint is proposed,which fuses prior information with other sensor information in the form of constraints.Firstly,the train precise track constraint method of the train is proposed,and the plane position constraint and train motion state constraints are analysed.A model for combining prior information with constraints is established.Then an adaptive H∞filter with combination constraints is derived based on the adaptive adjustment method of the robustness factor.Finally,the positioning effect of the proposed algorithm is simulated and analysed under the conditions of a straight track and a curved track.The results show that the positioning accuracy of the algorithm with constrained filtering is significantly better than that of the algorithm without constrained filtering and that the algorithm with constrained filtering can achieve better performance when combined with track and condition information,which can significantly reduce the train positioning error.The effectiveness of the proposed algorithm is verified. 展开更多
关键词 Train positioning combination constraint adaptive H_(∞)filter
下载PDF
Dynamic characteristics of multi-span spinning beams with elastic constraints under an axial compressive force
5
作者 Xiaodong GUO Zhu SU Lifeng WANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第2期295-310,共16页
A theoretical model for the multi-span spinning beams with elastic constraints under an axial compressive force is proposed.The displacement and bending angle functions are represented through an improved Fourier seri... A theoretical model for the multi-span spinning beams with elastic constraints under an axial compressive force is proposed.The displacement and bending angle functions are represented through an improved Fourier series,which ensures the continuity of the derivative at the boundary and enhances the convergence.The exact characteristic equations of the multi-span spinning beams with elastic constraints under an axial compressive force are derived by the Lagrange equation.The efficiency and accuracy of the present method are validated in comparison with the finite element method(FEM)and other methods.The effects of the boundary spring stiffness,the number of spans,the spinning velocity,and the axial compressive force on the dynamic characteristics of the multi-span spinning beams are studied.The results show that the present method can freely simulate any boundary constraints without modifying the solution process.The elastic range of linear springs is larger than that of torsion springs,and it is not affected by the number of spans.With an increase in the axial compressive force,the attenuation rate of the natural frequency of a spinning beam with a large number of spans becomes larger,while the attenuation rate with an elastic boundary is lower than that under a classic simply supported boundary. 展开更多
关键词 multi-span spinning beam elastic constraint improved Fourier series free vibration semi-analytical solution
下载PDF
Dynamic Constraint-Driven Event-Triggered Control of Strict-Feedback Systems Without Max/Min Values on Irregular Constraints
6
作者 Zhuwu Shao Yujuan Wang +1 位作者 Zeqiang Li Yongduan Song 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第3期569-580,共12页
This work proposes an event-triggered adaptive control approach for a class of uncertain nonlinear systems under irregular constraints.Unlike the constraints considered in most existing papers,here the external irregu... This work proposes an event-triggered adaptive control approach for a class of uncertain nonlinear systems under irregular constraints.Unlike the constraints considered in most existing papers,here the external irregular constraints are considered and a constraints switching mechanism(CSM)is introduced to circumvent the difficulties arising from irregular output constraints.Based on the CSM,a new class of generalized barrier functions are constructed,which allows the control results to be independent of the maximum and minimum values(MMVs)of constraints and thus extends the existing results.Finally,we proposed a novel dynamic constraint-driven event-triggered strategy(DCDETS),under which the stress on signal transmission is reduced greatly and no constraints are violated by making a dynamic trade-off among system state,external constraints,and inter-execution intervals.It is proved that the system output is driven to close to the reference trajectory and the semi-global stability is guaranteed under the proposed control scheme,regardless of the external irregular output constraints.Simulation also verifies the effectiveness and benefits of the proposed method. 展开更多
关键词 Adaptive control dynamic constraint-driven event-triggered control irregular output constraints nonlinear strict-feed-back systems
下载PDF
State-Owned Capital Participation in Private Enterprises:A Perspective of Debt Financing
7
作者 He Dexu Zeng Min Zhang Shuonan 《China Economist》 2024年第1期14-42,共29页
This study takes debt financing as the entry point and explores the impact of state-owned capital participation in private enterprises from the perspectives of“unarticulated rules”and“articulated rules”.The study ... This study takes debt financing as the entry point and explores the impact of state-owned capital participation in private enterprises from the perspectives of“unarticulated rules”and“articulated rules”.The study finds that state-owned capital participation significantly reduces the debt financing costs of private enterprises and expands the scale of their debt financing.This conclusion remains valid after a series of endogeneity and robustness tests.Further analysis of the mechanism reveals that state-owned capital participation improves the debt financing of private enterprises through multiple channels:Enhancing their social reputation,mitigating the“statistical bias”they face,optimizing their information quality,and reducing the“shareholder-creditor”agency problems.This paper conceptualizes these benefits as the“complementary advantages of heterogeneous shareholders”.This not only constructs a theoretical framework for“reverse mixed-ownership reform”but also better narrates the Chinese story of“mixed-ownership reform”by adopting a more universally applicable theory of equity structure.Additionally,the paper supplements existing research on the macro-and meso-level relationship between the government and the market by exploring the government’s positive role at the micro-level. 展开更多
关键词 Mixed-ownership reform reverse mixed-ownership reform state-owned capital debt financing heterogeneous shareholders
下载PDF
An intelligent automatic correlation method of oilbearing strata based on pattern constraints:An example of accretionary stratigraphy of Shishen 100 block in Shinan Oilfield of Bohai Bay Basin,East China
8
作者 WU Degang WU Shenghe +1 位作者 LIU Lei SUN Yide 《Petroleum Exploration and Development》 SCIE 2024年第1期180-192,共13页
Aiming at the problem that the data-driven automatic correlation methods which are difficult to adapt to the automatic correlation of oil-bearing strata with large changes in lateral sedimentary facies and strata thic... Aiming at the problem that the data-driven automatic correlation methods which are difficult to adapt to the automatic correlation of oil-bearing strata with large changes in lateral sedimentary facies and strata thickness,an intelligent automatic correlation method of oil-bearing strata based on pattern constraints is formed.We propose to introduce knowledge-driven in automatic correlation of oil-bearing strata,constraining the correlation process by stratigraphic sedimentary patterns and improving the similarity measuring machine and conditional constraint dynamic time warping algorithm to automate the correlation of marker layers and the interfaces of each stratum.The application in Shishen 100 block in the Shinan Oilfield of the Bohai Bay Basin shows that the coincidence rate of the marker layers identified by this method is over 95.00%,and the average coincidence rate of identified oil-bearing strata reaches 90.02% compared to artificial correlation results,which is about 17 percentage points higher than that of the existing automatic correlation methods.The accuracy of the automatic correlation of oil-bearing strata has been effectively improved. 展开更多
关键词 oil-bearing strata automatic correlation contrastive learning stratigraphic sedimentary pattern marker layer similarity measuring machine conditional constraint dynamic time warping algorithm
下载PDF
A Dimensional Reduction Approach Based on Essential Constraints in Linear Programming
9
作者 Eirini I. Nikolopoulou George S. Androulakis 《American Journal of Operations Research》 2024年第1期1-31,共31页
This paper presents a new dimension reduction strategy for medium and large-scale linear programming problems. The proposed method uses a subset of the original constraints and combines two algorithms: the weighted av... This paper presents a new dimension reduction strategy for medium and large-scale linear programming problems. The proposed method uses a subset of the original constraints and combines two algorithms: the weighted average and the cosine simplex algorithm. The first approach identifies binding constraints by using the weighted average of each constraint, whereas the second algorithm is based on the cosine similarity between the vector of the objective function and the constraints. These two approaches are complementary, and when used together, they locate the essential subset of initial constraints required for solving medium and large-scale linear programming problems. After reducing the dimension of the linear programming problem using the subset of the essential constraints, the solution method can be chosen from any suitable method for linear programming. The proposed approach was applied to a set of well-known benchmarks as well as more than 2000 random medium and large-scale linear programming problems. The results are promising, indicating that the new approach contributes to the reduction of both the size of the problems and the total number of iterations required. A tree-based classification model also confirmed the need for combining the two approaches. A detailed numerical example, the general numerical results, and the statistical analysis for the decision tree procedure are presented. 展开更多
关键词 Linear Programming Binding constraints Dimension Reduction Cosine Similarity Decision Analysis Decision Trees
下载PDF
On Enforcing Dyadic-type Homogeneous Binary Function Product Constraints in MatBase
10
作者 Christian Mancas 《Journal of Computer Science Research》 2024年第1期31-42,共12页
Homogeneous binary function products are frequently encountered in the sub-universes modeled by databases,spanning from genealogical trees and sports to education and healthcare,etc.Their properties must be discovered... Homogeneous binary function products are frequently encountered in the sub-universes modeled by databases,spanning from genealogical trees and sports to education and healthcare,etc.Their properties must be discovered and enforced by the software applications managing such data to guarantee plausibility.The(Elementary)Mathematical Data Model provides 17 types of dyadic-based homogeneous binary function product constraint categories.MatBase,an intelligent data and knowledge base management system prototype,allows database designers to simply declare them by only clicking corresponding checkboxes and automatically generates code for enforcing them.This paper describes the algorithms that MatBase uses for enforcing all 17 types of homogeneous binary function product constraint,which may also be employed by developers without access to MatBase. 展开更多
关键词 Database constraints Homogeneous binary function products Dyadic relations Modelling as programming The(Elementary)Mathematical Data Model MatBase
下载PDF
Does green governance affect financing constraints?Evidence from China's heavily polluting enterprises
11
作者 Pei Jose Liu Congjing Song Jiayuan Xin 《China Journal of Accounting Research》 2022年第4期22-46,共25页
Given the increasing focus on global sustainable development, many enterprises in developing countries such as China participate in green governance and scale up their green investment;however, many enterprises still ... Given the increasing focus on global sustainable development, many enterprises in developing countries such as China participate in green governance and scale up their green investment;however, many enterprises still experience financing difficulties. Our study investigates whether green governance can mitigate corporate financing constraints. Using a sample of Chinese, A-share listed, high-pollution enterprises from 2013 to 2018, we find that corporate green governance practices, including environmental performance and information disclosure, ease corporate financing constraints. This effect is pronounced in areas with high levels of financial development and for stateowned enterprises. This paper not only proposes a channel for alleviating enterprises’ financing constraints but also reveals the importance of industrial transformation and emissions reduction for energy-intensive industries in emerging markets. 展开更多
关键词 Green governance financing constraints Heavily polluting enterprises
原文传递
Financing Constraints and the Mode of Outward Foreign Direct Investment:Cross-Border Mergers and Acquisitions or Greenfield Investment
12
作者 Guanhong Jiang Jing Zeng 《China Finance and Economic Review》 2020年第4期46-66,共21页
In this paper,two investment modes,greenfield investment and cross-border mergers and acquisitions,are introduced on the basis of Manova(2008),and it is found that enterprises with less financing constraints tend to c... In this paper,two investment modes,greenfield investment and cross-border mergers and acquisitions,are introduced on the basis of Manova(2008),and it is found that enterprises with less financing constraints tend to choose cross-border mergers and acquisitions.Therefore,this paper takes Chinese industrial enterprises that conducted cross-border mergers and acquisitions and greenfield investment in 2003−2010 as examples to test the above hypothesis.The result shows that enterprises with lower financing constraints are more likely to choose cross-border mergers and acquisitions,while those with stronger constraints choose greenfield investment.More specifi cally,a 1%reduction in financing constraints raises the probability of choosing cross-border mergers and acquisitions by 2.51%.The authors also find that the influence of financing constraints varies under different investment motivation.For business service and production-related investment,enterprises with lower financing constraints tend to choose cross-border mergers and acquisitions;while for R&D investment,financing constraints have no impact on the choice of investment mode. 展开更多
关键词 financing constraints outward foreign direct investment cross-border mergers and acquisitions greenfield investment
下载PDF
Government Subsidy,Investment and Financing Constraints,and the Formation of Zombie Companies
13
作者 Jianbo Song Zihao Su Dehong Wang 《China Finance and Economic Review》 2019年第3期40-58,共19页
Zombie companies have serious adverse effects on economic development.The relationship between government subsidies and zombie companies is a focus in China’s supply-side structural reform.In this paper,we classify c... Zombie companies have serious adverse effects on economic development.The relationship between government subsidies and zombie companies is a focus in China’s supply-side structural reform.In this paper,we classify companies into two categories:investment-constrained companies lacking investment opportunities,and fi nancing-constrained companies with limited sources of capital.Based on data of A-share listed companies from 2007 to 2016,this paper examines the relationship between government subsidies and the zombification of companies subject to different types of constraints.We find that more government subsidies have been allotted to investment-constrained companies than financing-constrained ones;government subsidy is one of the various factors that have contributed to company zombification,but the correlation is only significant for investment-constrained companies;financing subsidy dedicated to expanding corporate financing is more effective in helping investment-constrained companies than government subsidies in general,but neither government subsidies nor financing subsidies are effective in preventing investment-constrained companies from turning into zombies.In the robustness test that controls the endogeneity problem of reverse causality,replaces proxy variables,lags subsidy variables and discusses the zombification of loss-making enterprises,the results are still valid.This paper provides a heterogeneous perspective to study the connection between government subsidies and the formation of zombie companies,and in view of subsidy mismatch,puts forward recommendations regarding the use of government subsidies. 展开更多
关键词 zombie company government subsidy financing subsidy investment constraints fi nancing constraints
下载PDF
UAVs cooperative task assignment and trajectory optimization with safety and time constraints 被引量:1
14
作者 Duo Zheng Yun-fei Zhang +1 位作者 Fan Li Peng Cheng 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第2期149-161,共13页
This paper proposes new methods and strategies for Multi-UAVs cooperative attacks with safety and time constraints in a complex environment.Delaunay triangle is designed to construct a map of the complex flight enviro... This paper proposes new methods and strategies for Multi-UAVs cooperative attacks with safety and time constraints in a complex environment.Delaunay triangle is designed to construct a map of the complex flight environment for aerial vehicles.Delaunay-Map,Safe Flight Corridor(SFC),and Relative Safe Flight Corridor(RSFC)are applied to ensure each UAV flight trajectory's safety.By using such techniques,it is possible to avoid the collision with obstacles and collision between UAVs.Bezier-curve is further developed to ensure that multi-UAVs can simultaneously reach the target at the specified time,and the trajectory is within the flight corridor.The trajectory tracking controller is also designed based on model predictive control to track the planned trajectory accurately.The simulation and experiment results are presented to verifying developed strategies of Multi-UAV cooperative attacks. 展开更多
关键词 MULTI-UAV Cooperative attacks Task assignment Trajectory optimization Safety constraints
下载PDF
Modeling and Adaptive Neural Network Control for a Soft Robotic Arm With Prescribed Motion Constraints 被引量:1
15
作者 Yan Yang Jiangtao Han +2 位作者 Zhijie Liu Zhijia Zhao Keum-Shik Hong 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第2期501-511,共11页
This paper presents a dynamic model and performance constraint control of a line-driven soft robotic arm.The dynamics model of the soft robotic arm is established by combining the screw theory and the Cosserat theory.... This paper presents a dynamic model and performance constraint control of a line-driven soft robotic arm.The dynamics model of the soft robotic arm is established by combining the screw theory and the Cosserat theory.The unmodeled dynamics of the system are considered,and an adaptive neural network controller is designed using the backstepping method and radial basis function neural network.The stability of the closed-loop system and the boundedness of the tracking error are verified using Lyapunov theory.The simulation results show that our approach is a good solution to the motion constraint problem of the line-driven soft robotic arm. 展开更多
关键词 Adaptive control cosserat theory prescribed motion constraints soft robotic arm
下载PDF
Anti-Disturbance Control for Tethered Aircraft System With Deferred Output Constraints 被引量:1
16
作者 Mengshi Song Fan Zhang +1 位作者 Bingxiao Huang Panfeng Huang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第2期474-485,共12页
In this paper,we investigate the peaking issue of extended state observers and the anti-disturbance control problem of tethered aircraft systems subject to the unstable flight of the main aircraft,airflow disturbances... In this paper,we investigate the peaking issue of extended state observers and the anti-disturbance control problem of tethered aircraft systems subject to the unstable flight of the main aircraft,airflow disturbances and deferred output constraints.Independent of exact initial values,a modified extended state observer is constructed from a shifting function such that not only the peaking issue inherently in the observer is circumvented completely but also the accurate estimation of the lumped disturbance is guaranteed.Meanwhile,to deal with deferred output constraints,an improved output constrained controller is employed by integrating the shifting function into the barrier Lyapunov function.Then,by combining the modified observer and the improved controller,an anti-disturbance control scheme is presented,which ensures that the outputs with any bounded initial conditions satisfy the constraints after a pre-specified finite time,and the tethered aircraft tracks the desired trajectory accurately.Finally,both a theoretical proof and simulation results verify the effectiveness of the proposed control scheme. 展开更多
关键词 Anti-disturbance control deferred output constraint extended state observer shifting function tethered aircraft system(TAS)
下载PDF
Trade credit financing for supply chain coordination under financial challenges:a multi‑leader–follower game approach
17
作者 Faranak Emtehani Nasim Nahavandi Farimah Mokhatab Rafiei 《Financial Innovation》 2023年第1期131-169,共39页
This study is designed to solve supply chain inefficiencies caused by some members’financial problems,such as capital shortages and financing restrictions in a stochastic environment.To this end,we have established a... This study is designed to solve supply chain inefficiencies caused by some members’financial problems,such as capital shortages and financing restrictions in a stochastic environment.To this end,we have established a supply chain finance framework by designing two novel coordinating contracts based on trade credit financing for different problem settings.These contracts are modeled in the form of multi-leader Stackelberg games that address horizontal and vertical competition in a supply chain consisting of multiple suppliers and a financially constrained manufacturer.However,previous studies in the trade credit literature have addressed only simple vertical competition,that is,seller-buyer competition.To solve the proposed models,two algorithms were developed by combining population-based metaheuristics,the Nash-domination concept,and the Nikaido-Isoda function.The results demonstrate that the proposed supply chain finance framework can eliminate supply chain inefficiencies and make a large profit for suppliers,as well as the financially constrained manufacturer.Furthermore,the results of the contracts’analysis showed that if the manufacturer is required to settle its payments to suppliers before the end of the period,the trade credit contract cannot coordinate the supply chain because of a lack of incentive for suppliers.However,if the manufacturer is allowed to extend its payments to the end of the period,the proposed trade credit financing contract can coordinate the supply chain.Finally,the sensitivity analysis results indicate that the worse the financial status of the manufacturer,the more bargaining power suppliers have in determining the contract parameters for more profit. 展开更多
关键词 Supply chain coordination Financial constraint Multi-leader–follower Stackelberg game Trade credit financing Population-based metaheuristics
下载PDF
Moult intensity constraints along the complete moult sequence of the House Sparrow(Passer domesticus)
18
作者 Santi Guallar Javier Quesada 《Avian Research》 SCIE CSCD 2023年第3期394-404,共11页
Sequence and intensity are two essential components of bird moult.While the moult sequences of remex tracts are highly homogenous across passerines,other tracts apparently show a high variability.Moreover,order of mou... Sequence and intensity are two essential components of bird moult.While the moult sequences of remex tracts are highly homogenous across passerines,other tracts apparently show a high variability.Moreover,order of moult activation among tracts are insufficiently known.Likewise,dynamics of moult intensity as moult progresses remains poorly known.Here,we provide detailed quantitative description of moult sequence and intensity in the House Sparrow(Passer domesticus).To understand their role,we tested two hypotheses on the:1) protection function of moult sequence,and 2) aerodynamic and physiological constraints on moult intensity.We scored percentage growth of 313 captured sparrows using the mass of the feathers of each tract(also length for remiges)to monitor moult intensity throughout the complete moult progress,which is defined as the fraction of new and growing feathers in a moulting bird relative to the total plumage.Moult sequence was highly variable both within wing coverts and among feather tracts,with moult sequence differing among all birds to some degree.We only found support for the protection function between greater coverts and both tertials and secondaries.Remex-moult intensity conformed to theoretical predictions,therefore lending support to the aerodynamic-constraint hypothesis.Furthermore,remex-moult speed plateaued during the central stages of moult progress.However,overall plumage-moult speed did not fit predictions of the physiological-constraint hypothesis,showing that the remex moult is only constrained by aerodynamics.Our results indicate that aerodynamic loss is not simply the inevitable effect of moult,but that moult is finely regulated to reduce aerodynamic loss.We propose that the moult of the House Sparrow is controlled through sequence and intensity adjustments in order to:1) avoid body and wing growth peaks;2) fulfil the protection function between some key feather tracts;3) reduce detrimental effects on flight ability;4) keep remex sequence fixed;and 5) relax remex replacement to last the whole moult duration. 展开更多
关键词 Functional constraints Local polynomial regression Passerine moult Physiological constraints Raggedness
下载PDF
Resource constraints and firm innovation:When less is more?
19
作者 Shuxing Chen Tao Shen 《Chinese Journal of Population,Resources and Environment》 2023年第3期172-180,共9页
This paper explores the relationship between resource constraints and innovation of new firms.Drawing upon the relevant literature,we incorporate resource constraints as the antecedent to the bricolage-innovation link... This paper explores the relationship between resource constraints and innovation of new firms.Drawing upon the relevant literature,we incorporate resource constraints as the antecedent to the bricolage-innovation link.Compared to prior studies that treated resource constraints as a one-dimensional variable,we operationalize it along two dimensions:knowledge constraints and financial constraints.Our argument posits that knowledge constraints and financial constraints act as catalysts for innovation in new firms,with bricolage serving as a mediating role.To test our hypotheses,we conducted a survey involving 183 entrepreneurs in the United States.The data analysis demonstrates that bricolage fully mediates the relationship between knowledge con‐straints and innovation and partially mediates the relationship between financial constraints and innovation.Theoretical and practical implications are discussed. 展开更多
关键词 Resource constraints Knowledge constraints Financial constraints BRICOLAGE Firm innovation
下载PDF
Fixed-Time Neural Control of a Quadrotor UAV With Input and Attitude Constraints
20
作者 Benke Gao Yan-Jun Liu Lei Liu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第1期281-283,共3页
Dear Editor, This letter is concerned with the attitude control of a quadrotor unmanned aerial vehicle(UAV) subject to the input constraint, attitude constraint and model uncertainty. Firstly, we construct an auxiliar... Dear Editor, This letter is concerned with the attitude control of a quadrotor unmanned aerial vehicle(UAV) subject to the input constraint, attitude constraint and model uncertainty. Firstly, we construct an auxiliary system to eliminate the adverse impact of the input saturation.Secondly, we introduce the nonlinear state-dependent function to deal with the attitude constraint directly. Thirdly, the neural network is utilized to identify the unknown terms in the system. Finally. 展开更多
关键词 ATTITUDE CONSTRAINT eliminate
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部