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Big Earth Data 2023年第4期7卷 937-960页

作者： Sarvarbek Eltazarov Ihtiyor Bobojonov Lena Kuhn Thomas Glauben department of Agricultural Markets Marketing and World Agricultural TradeLeibniz Institute of Agricultural Development in Transition Economies(IAMO)HalleGermany

Open-access gridded climate products have been suggested as a potential source of data for index insurance design and operation in data-limited ***,index insurance requires climate data with long historical records,global geographical coverage and fine spatial resolution at the same time,which is nearly impossible to satisfy,especially with open-access *** this paper,we spatially downscaled gridded climate data(precipitation,temperature,and soil moisture)in coarse spatial resolution with globally available longterm historical records to finer spatial resolution,using satellite-based data and machine learning *** then investigated the effect of index insurance contracts based on downscaled climate data for hedging spring wheat *** study employed countylevel spring wheat yield data between 1982 and 2018 from 56 counties overall in Kazakhstan and *** results showed that in the majority of cases(70%),hedging effectiveness of index insurances increases when climate data is spatially downscaled with a machine learning *** improvements are statistically significant(p≤0.05).Among other climate data,more improvements in hedging effectiveness were observed when the insurance design was based on downscaled temperature and precipitation ***,this study highlights the reasonability and benefits of downscaling climate data for insurance design and operation.

关键词： Climate risk management risk reduction extreme weather random forest ESA parametric insurance

STUDY ON THE CENTRALIZATION STRATEGY OF THE BLOOD ALLOCATION AMONG DIFFERENT departmentS WITHIN A HOSPITAL

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Journal of Systems Science and Systems Engineering 2018年第4期27卷 417-434页

作者： Jingnan Duan Qiang Su Yanhong Zhu Yuanshan Lu School of economies and Management Tongii University Shanghai 200092 China Shanghai General Hospital Shanghai 200080 China

By far, the researches on how to distribute blood products among different departments in hospital have not been further studied, though the problem of blood shortage and wastage that caused by improper blood allocation is severe, which may endanger patient＇s lives and impose considerable costs on hospitals. In order to solve this problem, this paper mainly studies on how to distribute the blood items among different departments within a hospital and investigates the allocation approach with the novel management method by centralizing the inventory of several different departments. By integrating the blood inventory requirements of some departments, the hospital could reduce the rate of blood shortage and wastage effectively, release the pressure of the occupancy of resources and reduce the bullwhip effect of blood products. This paper illustrates the centralization principle in hospital and formulates the mixed integer programming model to work out the optimal allocation network scheme and the optimal inventory setting for every department. And the results of the numerical example demonstrate that this centralization method could considerably reduce blood shortage and wastage in hospital by about 72% and 90% respectively. Furthermore, it could decrease the total cost by about 108,540 RMB a month on blood supply chain management in the hospital and improve the effect of some certain surgeries by transfusing the fresh blood to patients.

关键词： Blood allocation inventory management centralization strategy bullwhip effect

Productivity and Export Performance: Micro-Level Evidence from the Manufacturing Sector in Nigeria

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2019年第3期14卷 428-460页

作者： Kanang Amos Akims Dianah Mukwate Ngui department of Economics University of JosJos 930001Nigeria School of economies Kenyatta UniversityNairobiKenya

This paper investigates how productivity influences firms' *** finn characteristics are employed to test the self-selection hypothesis alongside the effects of firms' productivity on their share of exports in total *** a pseudo-panel data set constructed from the firm-level data for the manufacturing sector in Nigeria,we find no evidence that higher productivity influences the decision on whether or not a firm would participate in ***,it is established that higher productivity increases the share of exports in total sales of firms that are already participating in foreign markets.A policy implication of our result is that Nigeria can realize a larger share of manufactured exports in total merchandise exports by directing efforts towards improving primarily the productivity of firms that are already involved in exports.

关键词： productivity self-selection export performance manufacturing sector

City Size,Population Concentration and Productivity: Evidence from China

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China & World Economy 2019年第1期27卷 110-131页

作者： Jie Shen Chunlai Chen Mengyu Yang Keyun Zhang department of International economies University of International RelationsChina Crawford School of Public Policy Australian National UniversityAustralia School of economies Yunnan UniversityChina Institution of Regional and Urban Economics Renmin UniversityChina

This paper investigates the impact of China's city size and urban population concentration on city productivity by developing a distinctive index based on global nighttime light *** the panel data of 280 prefecture cities from 2004 to 2013 and employing dynamic system generalized method of moments and panel threshold model regression techniques,our results show that city size has a positive impact on city productivity;therefore,cities in China still have the potential to *** moderate urban population concentration can benefit city productivity,excessively concentrated urban population distribution may impede the growth of city *** also find that the level of labor income significantly affects the impacts of urban agglomeration on labor ***,our results imply that city development policies should focus more on how to appropriately allocate economic activities and adjust population distribution in urban areas according to different stages of economic development.

关键词： city size nighttime light data population concentration productivity

Do credit constraints affect households'economic vulnerability?Empirical evidence from rural China

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Journal of Integrative Agriculture 2021年第9期20卷 2552-2568页

作者： PENG Yan-ling Yanjun REN LI Hou-jian College of Economics Sichuan Agricultural UniversityChengdu 611130P.R.China department of Agricultural Markets Leibniz Institute of Agricultural Development in Transition EconomiesHalle(Saale)06120Germany

Poverty alleviation is still one of the major challenges in developing countries,especially in transitional economy like *** the perspective of anti-poverty,this paper examines the impact of formal credit constraints(FCCs)and informal credit constraints(IFCCs)on economic vulnerability(EV)using the data from the China Household Income Project(CHIP)survey for 2013(CHIPs 2013)of rural *** potential endogeneity problem of credit constraints(CCs)is addressed by applying the control function approach within an ordered probit *** results show that both FCCs and IFCCs have a robust positive and significant impact on the EV of rural households and that the impact of FCCs is greater than that of *** identify the potential mechanisms through which CCs affect EV,the seemingly unrelated regressions are used and the potential intercorrelation among these mechanisms is *** find that the impact of CCs on EV is partly mediated by health,trust,per capita financial assets and per capita income,whereby health and per capita income contribute to most of the total indirect ***,policies focus on supply-side and demand-side to improve credit accessibility could reduce rural households'EV,especially through its positive effect on health and per capita income.

关键词： credit constraints economic vulnerability causal mediation mechanisms rural China

Quasi-Networks in Social Relational Systems

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Systems Science and Systems Engineering 1992年第1期2卷 25-33页

作者： Robert P.Gilles Pieter H.M.Ruys department of economies Virginia Polytechnic Institute & State UniversityDepartment of Econometrics Tilburg University Blacksburg Virginia USATilburgthe Netherlands

In social sciences it is more or less generally acknowledged that (social) networks seem to be the natural tool in the organization of social activity. In the liteature on the mathematical description of social phenomena the concept of a network is hardly *** this paper we focus on the development of a’possible mathematical formualtion of the properties of a social network and a minimal and nearly complete social relational subsystem as a quasi-network within the setting of an economic trade system.

关键词： social relational system quasi-network.

FINITE DIFFERENCE APPROXIMATION FOR PRICING THE AMERICAN LOOKBACK OPTION

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Journal of Computational Mathematics 2009年第4期27卷 484-494页

作者： Tie Zhang Shuhua Zhang Danmei Zhu department of Mathematics School of Information Science and Engineering Northeastern University Shenyang 110003 China Research Center for Mathematics and economies Tianjin University of Finance and Economics Tianjin 300222 China department of Mathematics School of Information Science and Engineering Northeastern University Shenyang 110004 China

In this paper we are concerned with the pricing of lookback options with American type constrains. Based on the differential linear complementary formula associated with the pricing problem, an implicit difference scheme is constructed and analyzed. We show that there exists a unique difference solution which is unconditionally stable. Using the notion of viscosity solutions, we also prove that the finite difference solution converges uniformly to the viscosity solution of the continuous problem. Furthermore, by means of the variational inequality analysis method, the O（△t ＋ △x^2）-order error estimate is derived in the discrete L2-norm provided that the continuous problem is sufficiently regular. In addition, a numerical example is provided to illustrate the theoretical results.

关键词： American lookback options Finite difference approximation Stability andconvergence Error estimates.

A numerical local orthogonal transform method forstratified waveguides

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第12期11卷 998-1008页

作者： Peng LI Wei-zhou ZHONG Guo-sheng LI Zhi-hua CHEN School of economies and Finance Xi'an Jiaotong University Xi'an 710061 China department of Mathematics North China University of Water Conservancy and Electric Power Zhengzhou 450045 China department of Mathematics Zhongyuan University of Technology Zhengzhou 450007 China Science department Zhijiang College of Zhejiang University of Technology Hangzhou 310027 China

Flattening of the interfaces is necessary in computing wave propagation along strati?ed waveguides in large range step sizes while using marching methods. When the supposition that there exists one horizontal straight line in two adjacent interfaces does not hold, the previously suggested local orthogonal transform method with an analytical formulation is not feasible. This paper presents a numerical coordinate transform and an equation transform to perform the transforms numerically for waveguides without satisfying the supposition. The boundary value problem is then reduced to an initial value problem by one-way reformulation based on the Dirichlet-to-Neumann (DtN) map. This method is applicable in solving long-range wave propagation problems in slowly varying waveguides with a multilayered medium structure.

关键词： Helmholtz equation Local orthogonal transform Dirichlet-to-Neumann (DtN) reformulation Marching method Internal interface

Contribution of Lake Victoria Small-scale Fisheries to Poverty Alleviation： A Case Study of Tanzania Small-scale Fisheries

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Journal of Agricultural Science and Technology(B) 2012年第12期2卷 1268-1278页

作者： Odass Bilame department of economies St. Augustine University of Tanzania Mwanza Tanzania

This paper has attempted to show the contribution of Lake Victoria small-scale fisheries to poverty alleviation. Two districts in Mwanza region in the Lake Victoria Zone were identified for a field research. The two districts are Sengerema and Ilemela. The results show that during high catch season both fishers and fishing gear owners generated high incomes, although gear owners were relatively far better than fishers. This was true for both Sardines and Nile perch fisheries. For instance, during high catch season, 39 sardine fishers each generated monthly income that ranged between $300 and $1,100, and 18 further fishers each generated income that was below $300. However, during low catch season, the incomes generated were very low for both fishers and gear owners to an extent of not even recovering the variable costs. The scenario was different with Nile perch fishers, out of 53 fishers that were sampled, 44 fishers each generated net monthly income that was below $400 during high catch season and during low catch season, 46 out of 53 fishers each generated net monthly income that was below $200. Fishers were the hardest hit during low catch season.

关键词： Fisheries small-scale fisheries fishers and gear owners poverty alleviation.

Corporate Social Responsibility： An Analysis on Consumer Perception

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Journal of Agricultural Science and Technology(A) 2012年第9期2卷 1119-1125页

作者： Flavio Boccia Virginia Samo department of Economics Faculty of Economies "Parthenope "" University of Naples Naples 80133 Italy

The purpose of this paper is to consider and analyze the profile of modem consumer （careful to consequences of its purchasing decisions in terms of social, ethical and environmental aspects）, in order to identify the role of corporate social responsibility （CSR） for consumer through a study on critical, ethical and responsible purchase of food products. The problem is investigated empirically through a choice experiment method, which is a stated preference method based on a household survey, and through the analysis of the survey on consumer perception. In the food industry, the choice of goods and services requires the consumer decisions that seem to be increasingly dependent on factors not attributable only to the quality/price relationship, instead, they also involve issues directly related to ethics, environment and protection of labor. Today, companies do not limit themselves to undertake CSR, but often they choose to bring the stakeholders aware of such conduct, in an attempt to improve corporate reputation and business results. Therefore, it is to outline a synergy between companies＇ businesses and consumer＇s choice. The findings are based on data from an Italian region, and as such are not directly extendable elsewhere, although they may result to be of interest to other industrialized areas. The paper offers a comprehensive view of relationship between consumers and theme of social responsibility, and how they interface with firms （especially agri-food big companies） and their products; role that CSR plays in relation to the impact it can have on the consumption of food products from buyers; importance that the consumer gives to CSR when purchasing a food product and consumers＇ receptiveness towards sustainable strategies; knowledge degree of particular food categories; consumer willingness to purchase ethically oriented companies＇ products.

关键词： Choice company consumption food responsibility.