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Can whole steps of grain production be outsourced? Empirical analysis based on the three provinces of Jiangsu,Jilin,and Sichuan in China

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Journal of Integrative Agriculture 2024年第1期23卷 336-347页

作者： Jiacheng Liu Shengzhi Mao Qiufen Zheng Zhigang Xu school of Finance and Taxation Nanjing University of Finance and EconomicsJiangsu 210023China school of economics Southwestern University of Finance and EconomicsSichuan 611130China school of economics and Management Nanjing Agricultural UniversityJiangsu 210095China

Certain outsourcing services for agricultural management in China,such as pest control in grain production,have experienced prolonged sluggishness,contrasting with the relatively high level of outsourcing services observed in harvesting,land preparation,and *** study examines the feasibility of implementing whole-step outsourcing in grain production by conducting a case study of rice and maize production in Jiangsu,Jilin,and Sichuan provinces in *** provision of outsourcing services hinges on two essential conditions:technological advancements fostering specialized production and economies of scale,coupled with a market size sufficient to realize the aforementioned potential economies of *** results showed that outsourcing pest control or harvesting services had varying economies of *** outsourcing services in pest control were less common than in harvesting services,and their marginal growth space of the economies of scale with technological change was also *** by the operational characteristics of pest control itself,the market scale of its professional services is ***,achieving the whole-step outsourcing of grain production necessitates not only technological innovation but also effective policy interventions to overcome the constraints of market *** interventions include(1)optimizing crop layouts between planning regions and reducing land fragmentation and(2)supplying timely and effective inter-regional agricultural information for service providers aided by information technology.

关键词： outsourcing services economy of scale technical conditions market scale

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Dynamic Development Characteristics and Driving Factors of High Quality Development Level in China’s Five Major Urban Agglomerations

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Chinese Geographical Science 2024年第5期34卷 777-790页

作者： ZOU Weiyong XU Lingli school of economics Guangdong Ocean UniversityZhanjiang 524088China school of economics Shanghai UniversityShanghai 200444China

High-quality development is the primary task of comprehensively building a socialist,modern country,as well as the primary task of building urban agglomerations in *** on the five development concepts,this paper used the entropy method to meas-ure the High Quality Development Index(HQDI)of the five major urban *** results showed that the HQDI of the five major urban agglomerations shows a fluctuating upward ***,using the Dagum Gini coefficient to explore the sources of HQDI development differences in urban agglomerations,we found that the main source of HQDI differences in urban agglomerations was inter-regional differences,while intra-regional differences were not ***,kernel density estimation was used to test the dynam-ic evolution trend of HQDI within urban *** was a polarisation phenomenon in the HQDI of urban agglomerations,such as the Pearl River Delta urban agglomeration and the Chengdu-Chongqing urban *** overall,the degree of imbal-ance had ***,using geographic detectors to examine the driving factors of HQDI in urban agglomerations,we found that the main driving forces for improving HQDI in urban agglomerations were economic growth,artificial intelligence technology and fisc-al *** the interaction factors had greater explanatory power for the spatial differentiation of HQDI,which can be di-vided into two types:two-factor improvement and non-linear *** study is conducive to improving and enriching the the-oretical system for evaluating the high quality development of urban agglomerations,and provides policy references for promoting the high quality development of urban agglomerations.

关键词： urban agglomeration High Quality Development Index(HQDI) spatio-temporal evolution driving factors

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Analyzing the Dissemination of News by Model Averaging and Subsampling

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Journal of Systems Science & Complexity 2024年第5期37卷 2104-2131页

作者： ZOU Jiahui school of Statistics Capital University of Economics and Business

The dissemination of news is a vital topic in management science, social science and data science. With the development of technology, the sample sizes and dimensions of digital news data increase remarkably. To alleviate the computational burden in big data, this paper proposes a method to deal with massive and moderate-dimensional data for linear regression models via combing model averaging and subsampling methodologies. The author first samples a subsample from the full data according to some special probabilities and split covariates into several groups to construct candidate models. Then, the author solves each candidate model and calculates the model-averaging weights to combine these estimators based on this subsample. Additionally, the asymptotic optimality in subsampling form is proved and the way to calculate optimal subsampling probabilities is *** author also illustrates the proposed method via simulations, which shows it takes less running time than that of the full data and generates more accurate estimations than uniform subsampling. Finally,the author applies the proposed method to analyze and predict the sharing number of news, and finds the topic, vocabulary and dissemination time are the determinants.

关键词： Asymptotic optimality dissemination of news linear regression models model averaging optimal subsampling

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Non-Convex Optimization of Resource Allocation in Fog Computing Using Successive Approximation

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Journal of Systems Science & Complexity 2024年第2期37卷 805-840页

作者： LI Shiyong LIU Huan LI Wenzhe SUN Wei school of economics and Management Yanshan UniversityQinhuangdao 066000China

Fog computing can deliver low delay and advanced IT services to end users with substantially reduced energy ***,with soaring demands for resource service and the limited capability of fog nodes,how to allocate and manage fog computing resources properly and stably has become the ***,the paper investigates the utility optimization-based resource allocation problem between fog nodes and end users in fog *** authors first introduce four types of utility functions due to the diverse tasks executed by end users and build the resource allocation model aiming at utility ***,for only the elastic tasks,the convex optimization method is applied to obtain the optimal results;for the elastic and inelastic tasks,with the assistance of Jensen’s inequality,the primal non-convex model is approximated to a sequence of equivalent convex optimization problems using successive approximation ***,a two-layer algorithm is proposed that globally converges to an optimal solution of the original ***,numerical simulation results demonstrate its superior performance and *** with other works,the authors emphasize the analysis for non-convex optimization problems and the diversity of tasks in fog computing resource allocation.

关键词： Fog computing non-convex optimization optimal resource allocation successive approximation method utility function

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Customer Joining Behavior and Regulation Strategy in Visible Multi-Server Queues with Synchronous Vacations of Partial Servers

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Journal of Systems Science & Complexity 2024年第3期37卷 1209-1232页

作者： SUN Wei WANG Hao XIE Xumeng LI Shiyong school of economics and Management Yanshan UniversityQinhuangdao 066004China

This paper studies customer joining behavior and system regulation strategy in nonexhaustive visible M/M/m queues with synchronous vacations of a part of the *** this part of the servers are idle,they take multiple vacations simultaneously(vacation period).Until there are customers waiting in the queue,they are reactivated and all servers are busy or idle(busy period).The authors call this part of the servers as“partial servers”.In view of the fully visible queue and the almost visible queue,the authors obtain customers’equilibrium joining threshold strategies and their socially optimal joining threshold strategies,respectively,and observe that customer joining behavior in equilibrium generally makes the system overcrowded,which makes the equilibrium social welfare lower than the optimal social *** regulation,interestingly,for optimizing social welfare,the system manager hopes not only customers arriving in vacation period pay attention to the number of partial servers,but also customers arriving in busy period should care about it rather than ***,arranging more servers for vacation does not necessarily lead to the decrease of social welfare on condition that the number of partial servers is close to *** for the information advantage of the fully visible case,it is not obvious for increasing social welfare and even unfavorable to servers’profit unless the number of partial servers is big ***,given the different composition of social welfare,there exists the optimal number of partial servers and the optimal arrival rate of customers for maximizing social welfare.

关键词： Customer behavior non-exhaustive service partial servers regulation strategy synchronous vacations visible queue

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A comprehensive framework for predicting public opinion by tracking multi-informational dynamics

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Frontiers of Computer Science 2024年第4期18卷 197-199页

作者： Mingtao SUN Yan WEI Shan JIANG Guozhu JIA school of economics and Management Beihang UniversityBeijing 100191China school of Software Beihang UniversityBeijing 100191China school of economics Wuhan University of TechnologyWuhan 430070China

1 Introduction In the digital landscape,trivial rumors can spark significant online reactions[1].Accurate prediction of public opinion is important for crisis management,misinformation mitigation,and fostering public ***,existing methods often fail to thoroughly investigate multiple informational factors and their timely interactions[2-4],thereby limiting their efficacy in analysing public opinion.

关键词： thereby thoroughly limiting

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Can Digital Transformation Definitely Improve Firms'Markups?

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China Finance and Economic Review 2024年第1期13卷 23-42页

作者： Xiang Dai Haowei Ma Erzhen Zhang school of economics Nanjing Audit University school of economics Nanjing University

In this paper,digital transformation is included in the heterogeneity model of *** on a general equilibrium analysis,we find that under the effect of diminishing marginal productivity,digital transformation does not always have a positive impact on firms'markups,but has an"inverted U-shaped"nonlinear influence,which first promotes and then inhibits *** innovation and firm productivity are the key micro-mechanisms for the above effects to play a *** on the analysis of typical facts and empirical data of listed companies,the measurement test yields the following ***,digital transformation can significantly improve firms'markups when it is below a specific threshold value,but it will have a negative impact when it exceeds this *** is,there is an"inverted U-shaped"nonlinear relationship between digital transformation and firms'***,the heterogeneity analysis shows that digital transformation has a greater effect on the markups of state-owned firms,export firms and technology-intensive firms than on the markups of other ***,digital transformation has an impact on firms'markups through two key mechanisms:firm innovation ability and production *** quantitative empirical results confirm the correctness of the theoretical ***,firms need to grasp the strategic opportunities brought by the progress of digital technology and accelerate the process of promoting the digital *** should make proper choices in the selection and arrangement of key areas,as well as avoid possible problems such as"too much".In this way,we can better consolidate the micro foundation of China's high-quality economic development.

关键词： digital transformation firm markup rate inverted U-shaped

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The Role of Consumer Privacy Concerns in Shaping Platform Strategy for Online Markets

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Journal of the Operations Research Society of China 2024年第2期12卷 363-386页

作者： Jin-Kun Yang Yong-Rui Duan Jia-Zhen Huo school economics and Management Tongji UniversityShanghai 200092China

We investigate the effects of consumer privacy concerns on the pricing and personal data collection strategy of an online *** online platform derives revenues from disclosing consumer information to *** compete for the information in order to enable them to price discriminate and thus derive revenues from consumer purchases.A novel aspect of our research is that we allow the online platform to sell only a subset of consumer *** develop analytical models where consumers can/cannot protect their *** analysis yields three main ***,in the monopoly case,we find that when the consumer privacy disclosure aversion cost is relatively low,it is optimal for the platform to sell all consumer information to the ***,in the duopoly case,we illustrate that when the consumer privacy disclosure aversion cost is relatively low,the platform will sell all consumer information to only one firm;when the cost is moderate,the platform will choose to sell the information of only some consumers and to only one firm;when the cost is relatively high,the platform will select only some of the consumers and sell their information to both ***,it will be better for the platform to provide the information protection service for free when the privacy cost is low.

关键词： Price discrimination User privacy Consumer information Two-sided market Privacy disclosure aversion cost

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Research on the Asymmetric Effect of Fixed-Asset Investment on China's Primary Energy Production in the Context of Energy Transformation

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Journal of Systems Science & Complexity 2024年第3期37卷 1163-1183页

作者： CHAI Jian HE Peng ZHANG Xiaokong HOU Yamin school of economics and Management Xidian UniversityXi'an 710126China

Under China’s“Dual Carbon”target(DCT),“clean replacement”on the energy supply side and“electric energy replacement”on the energy consumption side are the ways to achieve energy ***,energy projects have a long construction period,complex technology categories,and investment risks that greatly affect the development of energy *** judging the effect of investment changes on primary energy production is of great practical significance to the realization of the *** on this,NARDL and TVP-SV-VAR models are innovatively used to reveal the nonlinear effect of fixed-asset investment on China’s primary energy *** results show that the marginal effect of investment growth on coal production is about 1.44 times that of investment ***,the marginal effect of oil and gas investment growth is about 1.21times that of investment *** to the influence of resource constraints,China’s traditional fossil energy still has varying degrees of path dependence on the investment-driven development *** non-fossil energy,investment in hydropower and nuclear power has an inverse correlation with the change in *** marginal efficiency and diseconomies of scale have hindered the development of the hydropower and nuclear power *** addition,the asymmetric effect is not yet significant for the short development time and technical constraints of wind and solar *** the impulse response results,the impact curves of investment in wind and solar power are generally positive,and investment has different degrees of time-delay and time-varying effects on various energy production,which verifies the heterogeneity of investment adjustment mechanisms in different energy industries.

关键词： "Dual Carbon"target fixed-asset investment primary energy NARDL nonlinearity

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Dynamic Analysis of Incentive Policy Impacts on Recycling of Retired Batteries for Electric Vehicles

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Journal of Systems Science and Information 2024年第4期12卷 491-514页

作者： Cuixia WANG Lang WEI school of Information Management Jiangxi University of Finance and Economics school of economics and Management Hunan College of Information

Electric Vehicles(EVs), as a low-carbon means of transportation, have promptly become popular worldwide in the past decade. Since the lifespan of batteries is limited, massive of Electric Vehicle Batteries(EVBs) are being retired, resulting in a rapid increase in the demand for the recycling of retired EVBs in recent years. However, due to high recycling costs and immature recycling technologies, EV manufacturers are facing significant challenges in recycling retired EVBs. China, as the country with the largest number of EV users in the world, is exploring effective incentive policies for the recycling of retired EVBs. In this context, we developed a system dynamics model to analyze the impact of incentive polices such as, recycling subsidies, technological progress, and carbon trading on the retired EVBs recycling. Results show that: 1) recycling subsidies can improve the recycling ratios quickly in the short term, and dynamic subsidies are more efficient than static subsidies; 2) the policy of technological advancement can reduce the recovery and cascade utilization cost, thus having a positive impact on battery recycling, but the policy effect has a time-delay; 3) the carbon trading policy is unable to promote efficient recycling due to the current low carbon prices; 4) dynamic subsidy and technological advancement policies complement each other, therefore, the combination of these two policies is the best way to promote the recycling of retired EVBs and reduce carbon emissions. It is hoped that this study will contribute to the ongoing debate on policies for the industrialization of retired EVBs recycling.

关键词： electric vehicles retired battery recycling policy impact system dynamics

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