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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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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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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 measure 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 dynamic 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 imbalance 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 fiscal *** the interaction factors had greater explanatory power for the spatial differentiation of HQDI,which can be divided into two types:two-factor improvement and non-linear *** study is conducive to improving and enriching the theoretical 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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Evaluation of the efficiency of urban solid waste management in Brazil by data envelopment analysis and possible variables of influence

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Waste Disposal and Sustainable Energy 2024年第2期6卷 283-295页

作者： Isabel das Merces Costa Marta Ferreira Dias Margarita Robaina GOvCOPP-Research unit on Governance Competitiveness and Public Policies and Analyst of UniversidadeEstadual de Feira de SantanaUniversidade de AveiroAveiroPortugal GOvCOPP-Research unit on Governance Competitiveness and Public PoliciesDEGEIT-Department of EconomicsManagementIndustrial Engineering and TourismUniversidade de AveiroAveiroPortugal

This article has the general objective of estimating the efficiency of urban solid waste management in 940 Brazilian munici-palities through Data Envelopment Analysis(DEA)technique and has specific objectives:(i)to estimate efficiency scores;(ii)to compare the performance between different groups of municipalities;and(ii)to analyze the profile of efficient munici-palities from the perspective of the guidelines of Law 12,305/2010 and socio-economic and environmental *** technique used was DEA with output-oriented and variable scale to return *** results showed higher efficiency scores in the municipalities with populations above 500,000 *** score variation ranged from 0.5(municipalities with populations<10,000 inhabitants)to 0.9(municipalities with more than 500,000 inhabitants).Of the sample set,only 12.34%of the municipalities were considered efficient,and when analyzing the efficient group,it was found that adherence to legislation was not a major factor in achieving efficiency.

关键词： Urban solid waste management Data envelopment analysis Efficiency Brazil Municipalities

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Women’s empowerment and food consumption:Evidence from female-headed households in Tanzania

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Journal of Integrative Agriculture 2024年第2期23卷 457-467页

作者： Mosses Lufuke Xu Tian College of economics and Management Nanjing Agricultural UniversityNanjing 210095China Department of economics The University of DodomaDodoma 41218Tanzania College of economics and Management China Agricultural UniversityBeijing 100083China Academy of Global Food economics and Policy China Agricultural UniversityBeijing 100083China

Despite the growing recognition of women’s increasing role in the household and corresponding empowerment programs in sub-Saharan Africa,intensive research on the relationship between women’s influence and household food consumption is *** the most recent(2017-2018)national household survey data from Tanzania,this study examined the influence of women’s empowerment on household food ***,we compared the monthly consumption of eight food categories between female-headed households(FHHs)and male-headed households(MHHs)using both descriptive statistics and the propensity score matching(PSM)***,we adopted the two-stage Linear Expenditure System and Almost Ideal Demand System model(LES-AIDS)to estimate income and price elasticities for the two household *** results show that FHHs consume bread and cereals,fish,oils and fats,vegetables,and confectionery(sugar,jam,honey,chocolate,etc.)more than ***,FHHs have a significantly higher income elasticity of demand for all food groups than *** are also more price elastic than MHHs in meat,fish,oils,fats,sugar,jam,honey,chocolate,etc.

关键词： women’s empowerment food consumption income elasticity price elasticity

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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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On the Pathwise Uniqueness of Solutions of One-dimensional Reflected Stochastic Differential Equations with Jumps

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 149-163页

作者： Hua Zhang School of Statistics and Data Science&Key Laboratory of Data Science in Finance and economics Jiangxi University of Finance and EconomicsNanchang330013China

In this paper, we are concerned with the problem of the pathwise uniqueness of one-dimensional reflected stochastic differential equations with jumps under the assumption of non-Lipschitz continuous coefficients whose... 详细信息

关键词： reflected diffusion processes with jumps pathwise uniqueness local time Meyer It?'s formula

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The Mechanism and Empirical Testing of the Impact of Cultural and Tourism Integration on Common Prosperity

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Journal of Resources and Ecology 2024年第4期15卷 1027-1038页

作者： PENG Yaping LIU Weizhong XIONG Changjiang BAI Xiang College of economics and Management Xinjiang Agricultural UniversityUrumqi 830052China Institute of Finance and economics Shanghai University of Finance and EconomicsShanghai 200434China

Achieving common prosperity is the essential requirement of Chinese modernization,and the integration of culture and tourism is of great significance as an important path to narrow the regional gap,and effectively“improve quality”and“increase income”.This study used the panel data of 30 provinces in China from 2010 to 2019,and conducted empirical tests by using the panel fixed effects model and the mediation effects *** results indicated that the integration of culture and tourism can significantly promote the realization of common *** integration can promote common prosperity by increasing the income and consumption level of urban and rural residents,the degree of equalization of basic public services and the capacity for sustainable *** analysis shows that there are regional differences in the promotion of common prosperity by cultural and tourism integration,which is particularly obvious in ethnic and non-ethnic ***,in response to the existing problems identified in the above analyses,countermeasure recommendations that align with the actual development are put forward.

关键词： cultural and tourism integration common prosperity urban-rural income gap mediating effect

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Climbing the Export Quality Ladder:Role of Human Capital

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China & World Economy 2024年第2期32卷 125-159页

作者： Xiaogang He Ruifeng Teng Dawei Feng School of Applied economics Jiangxi University of Finance and EconomicsChina

This study assesses the effect of human capital expansion on China's export product *** employs the difference-in-differences(DID)framework based on a quasi-natural experiment investigating the 1999 higher education enrollment expansion as the exogenous policy *** empirical results confirm that human capital expansion appreciably improved the quality of China's export *** capital expansion promoted the transformation and upgrading of old products and the development of new products in term of intensive margin;it strengthened the endowment advantages of incumbent high-quality export enterprises while preventing low-quality enterprises from entering the market through price competition on the extensive *** prevented quality ***,the study reveals that the improvement effect driven by human capital came from both innovation-induced and managerial efficiency improvement channels and was more prominent for large or foreign-funded enterprises in the eastern *** findings highlight the role of human capital in China's remarkable export performance from an endogenous growth perspective.

关键词： endogenous growth export product higher education expansion human capital quality improvement

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