AIM:To analysis of research hotspots and trends on the application of premium intraocular lens(PIOLs)in the past 2 decades.METHODS:The literature search was performed on the Web of Science and included PIOLs studies p...AIM:To analysis of research hotspots and trends on the application of premium intraocular lens(PIOLs)in the past 2 decades.METHODS:The literature search was performed on the Web of Science and included PIOLs studies published between January 2000 and December 2022.The retrieved literature was collated and analyzed by R-tool’s Bibliometrix package,CitNetExplorer,CiteSpace and other software.RESULTS:A total of 1801 articles about PIOLs were obtained,most of which were published in Spain and the United States.The organization that published the most articles was the University of Valencia in Spain.Alió JL,and Montés-Micó R,from Spain were the most influential authors in this field.The Journal of Cataract and Refractive Surgery and Journal of Refractive Surgery were the core journals for this field;the top 10 cited articles mainly focus on postoperative satisfaction with multifocal intraocular lens(IOLs)and postoperative results of toric IOLs.Through the keyword analysis,we found that trifocal IOLs,astigmatism and extended depth of focus(EDoF)IOLs are the most discussed topics at present,and the importance of astigmatism and the clinical application of the new generation of PIOLs are the emerging research trends.CONCLUSION:Bibliometric analysis can effectively help to identify multilevel concerns in PIOLs research and the prevailing research trends in the realm of PIOLs encompass the adoption of EDoF IOLs,trifocal IOLs,and their respective Toric models.展开更多
BACKGROUND The role of physical activity in diabetes is critical,influencing this disease's development,man-agement,and overall outcomes.In China,22.3%of adults do not meet the minimum level of physical activity r...BACKGROUND The role of physical activity in diabetes is critical,influencing this disease's development,man-agement,and overall outcomes.In China,22.3%of adults do not meet the minimum level of physical activity recommended by the World Health Organization.Therefore,it is imperative to identify the factors that contributing to lack of physical activity must be identified.AIM To investigate the relationship among delay discounting,delay aversion,glycated hemoglobin(HbA1c),and various levels of physical activity in Chinese adults diagnosed with type 2 diabetes mellitus(T2DM).METHODS In 2023,400 adults with T2DM were recruited from the People's Hospital of Linxia Hui Autonomous Prefecture of Gansu Province.A face-to-face questionnaire was used to gather demographic data and details on physical activity,delay discounting,and delay aversion.In addition,HbA1c levels were measured in all 400 participants.The primary independent variables considered were delay discounting and delay aversion.The outcome variables included HbA1c levels and different intensity levels of physical activity,including walking,moderate physical activity,and vigorous physical activity.Multiple linear regression models were utilized to assess the relationship between delay discounting,delay aversion,and HbA1c levels,along with the intensity of different physical activity measured in met-hours per week.RESULTS After controlling for the sample characteristics,delay discounting was negatively associated with moderate physical activity(β=-2.386,95%CI:-4.370 to-0.401).Meanwhile,delay aversion was negatively associated with the level of moderate physical activity(β=-3.527,95%CI:-5.578 to-1.476)in the multiple linear regression model,with statistically significant differences.CONCLUSION Elevated delay discounting and increased delay aversion correlated with reduced levels of moderate physical activity.Result suggests that delay discounting and aversion may influence engagement in moderate physical activity.This study recommends that health administration and government consider delay discounting and delay aversion when formulating behavioral intervention strategies and treatment guidelines involving physical activity for patients with T2DM,which may increase participation in physical activity.This study contributes a novel perspective to the research on physical activity in adults with T2DM by examining the significance of future health considerations and the role of emotional responses to delays.展开更多
Reinsurance is an effective risk management tool for insurers to stabilize their profitability. In a typical reinsurance treaty, an insurer cedes part of the loss to a reinsurer. As the insurer faces an increasing num...Reinsurance is an effective risk management tool for insurers to stabilize their profitability. In a typical reinsurance treaty, an insurer cedes part of the loss to a reinsurer. As the insurer faces an increasing number of total losses in the insurance market, the insurer might expect the reinsurer to bear an increasing proportion of the total loss, that is the insurer might expect the reinsurer to pay an increasing proportion of the total claim amount when he faces an increasing number of total claims in the insurance market. Motivated by this, we study the optimal reinsurance problem under the Vajda condition. To prevent moral hazard and reflect the spirit of reinsurance, we assume that the retained loss function is increasing and the ceded loss function satisfies the Vajda condition. We derive the explicit expression of the optimal reinsurance under the TVaR risk measure and TVaR premium principle from the perspective of both an insurer and a reinsurer. Our results show that the explicit expression of the optimal reinsurance is in the form of two or three interconnected line segments. Under an additional mild constraint, we get the optimal parameters and find the optimal reinsurance strategy is full reinsurance, no reinsurance, stop loss reinsurance, or quota-share reinsurance. Finally, we gave an example to analyze the impact of the weighting factor on optimal reinsurance.展开更多
Traditional machine learning metrics(TMLMs)are quite useful for the current research work precision,recall,accuracy,MSE and RMSE.Not enough for a practitioner to be confident about the performance and dependability of...Traditional machine learning metrics(TMLMs)are quite useful for the current research work precision,recall,accuracy,MSE and RMSE.Not enough for a practitioner to be confident about the performance and dependability of innovative interpretable model 85%–92%.We included in the prediction process,machine learning models(MLMs)with greater than 99%accuracy with a sensitivity of 95%–98%and specifically in the database.We need to explain the model to domain specialists through the MLMs.Human-understandable explanations in addition to ML professionals must establish trust in the prediction of our model.This is achieved by creating a model-independent,locally accurate explanation set that makes it better than the primary model.As we know that human interaction with machine learning systems on this model’s interpretability is more crucial.For supporting set validations in model selection insurance premium prediction.In this study,we proposed the use of the(LIME and SHAP)approach to understand research properly and explain a model developed using random forest regression to predict insurance premiums.The SHAP algorithm’s drawback,as seen in our experiments,is its lengthy computing time—to produce the findings,it must compute every possible combination.In addition,the experiments conducted were intended to focus on the model’s interpretability and explain its ability using LIME and SHAP,not the insurance premium charge prediction.Three experiments were conducted through experiment,one was to interpret the random forest regression model using LIME techniques.In experiment 2,we used the SHAP technique to interpret the model insurance premium prediction(IPP).展开更多
The polynomial spline model, which belongs to the static term structure model of interest rates, is studied. Every cash flow of the project is discounted relatively accurately by obtaining the discount rate from the s...The polynomial spline model, which belongs to the static term structure model of interest rates, is studied. Every cash flow of the project is discounted relatively accurately by obtaining the discount rate from the static term structure model of interest rates. A simple basic model, which belongs to the dynamic term structure model, is studied, and the option pricing formula under changing risk-free rates is obtained by bringing it into the option pricing formula. Both dynamic and static term structure models are estimated by the use of the data of buy-back rates and the Shanghai Stock Exchange, and an example is given to compare the differences between the traditional method and the method under the changes in the interest rates and the discount rates.展开更多
This paper studied the effects of crop insurance on agricultural output with an economic growth model. Based on Ramsey-Cass-Koopmans (RCK) model, a basic model of agriculture economic growth was developed. Extending...This paper studied the effects of crop insurance on agricultural output with an economic growth model. Based on Ramsey-Cass-Koopmans (RCK) model, a basic model of agriculture economic growth was developed. Extending the basic model to incorporate uncertainty and insurance mechanism, a risk model and a risk-insurance model were built to study the inlfuences of risk and crop insurance on agricultural output. Compared with the steady states of the three models, the following results are achieved:(i) agricultural output decreases if we introduce uncertainty into the risk-free model;(ii) crop insurance promotes agriculture economic growth if insurance mechanism is introduced into the risk model;(iii) premium subsidy constantly improves agricultural output. Our contribution is that we studied the effects of crop insurance and premium subsidy from the perspective of economic growth in a dynamic framework, and proved the output promotion of crop insurance theoretically.展开更多
We consider a risk model with a premium rate which varies with the level of free reserves. In this model, the occurrence of claims is described by a Cox process with Markov intensity process, and the influence of stoc...We consider a risk model with a premium rate which varies with the level of free reserves. In this model, the occurrence of claims is described by a Cox process with Markov intensity process, and the influence of stochastic factors is considered by adding a diffusion process. The integro-differential equation for the ruin probability is derived by a infinitesimal method. Key words ruin probability - variable premium rate - diffusion process - Markov intensity CLC number O 211.9 Foundation item: Supported by the National Natural Science Foundation of China (10071058, 70273029)展开更多
In this present paper, a deterministic lot size model is developed for deteriorating items with incremental quantity discounts. It is assumed that shortages are permitted to occur and fully backlogged. A simple solut...In this present paper, a deterministic lot size model is developed for deteriorating items with incremental quantity discounts. It is assumed that shortages are permitted to occur and fully backlogged. A simple solution procedure is shown for determining the optimal order lot size and the optimal order cycle. A numerical example is used to illustrate how the solution procedure works.展开更多
Probability discounting is defined as the devaluation of outcomes as the probability of receiving or paying those decreases. A q-exponential probability discounting model based on Tsallis’ statistics has been propose...Probability discounting is defined as the devaluation of outcomes as the probability of receiving or paying those decreases. A q-exponential probability discounting model based on Tsallis’ statistics has been proposed in econophysics (Takahashi, 2007, Physica A). We examined (a) fitness of the models to behavioral data of probability discounting of both gain and loss;and (b) relationships between parameters in the q-exponential probability discounting model across gain and loss. Our results demonstrated that, for both gain and loss, the q-exponential model better fits the behavioral data than exponential and hyperbolic functions, and there is the sign effect in q-exponential probability discounting. Relationships between Kahneman-Tversky’s prospect theory in behavioral economics and the q-exponential probability discounting are high-lightened.展开更多
Social discounting has been attracting attention in behavioral psychology, econophysics, and neuroeconomics. Several mathematical models have been proposed for social discounting;exponential discounting, hyperbolic di...Social discounting has been attracting attention in behavioral psychology, econophysics, and neuroeconomics. Several mathematical models have been proposed for social discounting;exponential discounting, hyperbolic discounting, a q-exponential discounting model based on Tsallis’ statistics. In order to experimentally examine the mathematical characteristics of the q-exponential social discounting models for gain and loss in humans, we estimated the parameters of the q-exponential social discounting models by assessing the points of subjective equality (indifference points) at seven social distances. We observed that gain was more steeply social-discounted than loss. Usefulness of the q-exponential social discounting model in social physics, econophysics, and cultural neuroeconomics are discussed.展开更多
In order to analyze the sealing performance of a new designed premium threaded connection,this paper studies the sealing reliability and sensitivity of the premium threaded connection at its most dangerous load condit...In order to analyze the sealing performance of a new designed premium threaded connection,this paper studies the sealing reliability and sensitivity of the premium threaded connection at its most dangerous load condition based on Kriging model.The load condition of premium threaded connection in deep well is so complex that the most dangerous load point of premium threaded connection under the typical series loads is studied by finite element analysis(FEA) method firstly.Since the FEA of the premium threaded connection is too time-consuming,Kriging model which is accurate and efficient for multidimensional and highly nonlinear problems is built to calculate the sealing reliability of the premium threaded connection at the most dangerous load point.Finally,the sealing sensitivity analysis of the premium threaded connection is performed by the method of variance-based global sensitivity analysis.The work in this paper could contribute for the analysis and further improvement of the premium threaded connection.展开更多
This paper has organized and summarized the economic analysis on climate change from five angles,namely,connotation of discount rate,identification of and dispute about discount rate,discounting way,impact of the disc...This paper has organized and summarized the economic analysis on climate change from five angles,namely,connotation of discount rate,identification of and dispute about discount rate,discounting way,impact of the discount rate,and the integrated evaluation model of climate change impact and the discount evaluation.As the climate change economic analysis shows,there is a major dispute about discount rate between the market school and the ethic school.Rate of discount largely relates to the present value of potential loss attributable to climate change,and then influences the selection of policies for adapting and slowing down climate change.In the past,the constant index discount was adopted as the main way.But with the full understanding of discount rate,the uncertainty of loss attributable to climate change has been considered in the discount.展开更多
This study examines the pricing of municipal bonds before and after a currency shock in Switzerland.Two approaches are used to decompose the municipal to treasuries bond spreads into liquidity,maturity,and default ris...This study examines the pricing of municipal bonds before and after a currency shock in Switzerland.Two approaches are used to decompose the municipal to treasuries bond spreads into liquidity,maturity,and default risk premiums.The first approach is the model of the cross-sectional instrumental variables,and the second approach is the model of the instrumental variables with panel data.This study examines the composition of spreads for both approaches,in three scenarios:before,throughout,and after the currency shock.The study performed Durbin-Wu-Hausman tests for each decisive model to verify endogeneity issues,including the Lagrangian Multiplier test,the Cragg-Donald Wald F statistic to confirm the relationship of instrumental and endogenous variables,and the structural break test(Bai-Perron test)to determine the existence of structural breaks in bond distortions.This study finds that the currency price distortions of the Swiss franc in January 2015 made long-run changes in the composition of the municipal bond spreads.This research contributes to the understanding of municipal bond pricing by showing that default risk accounts for a large portion of the municipal bond spread,while maturity risk plays a lesser role.According to our empirical findings,unexpected large currency price shocks may have long-term implications on the municipal bond spreads.展开更多
Solving the dispute over historical greenhouse gases emission responsibility is critical for the future climate agreement.This article borrows the methodology from the carbon budget proposal,but further develops this ...Solving the dispute over historical greenhouse gases emission responsibility is critical for the future climate agreement.This article borrows the methodology from the carbon budget proposal,but further develops this approach by proposing discount of the historical responsibility due to the technology advance.Firstly,it studies the Annex I countries'mitigation and financial responsibilities of the historical emission in the carbon budget proposal;furthermore,it analyzes the results and implications of the discount approach.Results show that the discount method significantly reduces the burden of the mitigation and financial responsibilities of the Annex I countries.Thus,we claim that the discount approach is a systematic,pragmatic,and fair approach to solve the historical responsibility dispute and financial problems for the post-2020international climate institutions.展开更多
The quantity discount contracts are investigated for a one-supplier-one-retailer supply chain with asymmetric information when the retailer's cost is disrupted. While the retailer's cost structure is asymmetri...The quantity discount contracts are investigated for a one-supplier-one-retailer supply chain with asymmetric information when the retailer's cost is disrupted. While the retailer's cost structure is asymmetric information, two all-unit quantity discount contract models, fixed expected-profit percentage discount(FEPD) and fixed wholesale-pricing percentage discount(FWPD) under asymmetric information are proposed in a regular scenario. When the retailer's cost distribution fluctuates due to disruptions, the optimal emergency strategies of supply chains are obtained under asymmetric information. Using numerical methods, the impact of cost disruptions on decisions about the regular wholesale price, discount wholesale price, order quantity and expected profits of the retailer, the supplier as well as the total system are analyzed. It is found that the FEPD policy is more robust and adaptable than the FWPD policy in disruption circumstances.展开更多
Agriculture plays a vital role in the growth and development of the High Plains Region of the United States. With the development and adoption of irrigation technology, this region was transformed into one of the most...Agriculture plays a vital role in the growth and development of the High Plains Region of the United States. With the development and adoption of irrigation technology, this region was transformed into one of the most agriculturally productive regions in the world [1]. The primary source of irrigation in this region is the Ogallala Aquifer. Currently, water from the aquifer is being used at a much faster rate than natural recharge can occur, resulting in a high rate of depletion from this finite resource. Depletion of scarce water resources will have a significant economic impact on the long-term sustainability of the region. The objective of this study is to evaluate the impact alternative prices and discount rates have on groundwater policy recommendations. Deterministic models of groundwater withdrawals were developed and used in order to analyze and evaluate the impact of high, average, and low crop prices in a status quo scenario as well as a policy scenario reducing irrigated acreage allocation. Furthermore, this study analyzes the effects and associated consequences of alternative discount rates on net and total revenue. As indicated by results of this study, alternative prices, costs, and discount rates utilized in a model have an effect on policy effectiveness.展开更多
First,using the law of large numbers,I analyze the setting principle of agricultural insurance premium rate,and take the case of setting of adult sow premium rate for study,to draw the conclusion that with the continu...First,using the law of large numbers,I analyze the setting principle of agricultural insurance premium rate,and take the case of setting of adult sow premium rate for study,to draw the conclusion that with the continuous promotion of agricultural insurance,increase in the types of agricultural insurance and increase in the number of the insured,the premium rate should also be adjusted opportunely.Then,on the basis of Bayes' theorem,I adjust and calibrate the claim frequency and the average claim,in order to correctly adjust agricultural insurance premium rate;take the case of forest insurance for premium rate adjustment analysis.In setting and adjustment of agricultural insurance premium rate,in order to make the expected results well close to the real results,it is necessary to apply the probability estimates in a large number of risk units;focus on the establishment of agricultural risk database,to timely adjust agricultural insurance premium rate.展开更多
Anomalies in decision over time (e.g., “hyperbolic time discounting”) and under risk (e.g., Allais paradox and hyperbolic probability discounting) have been attracting attention in behavioral and neuroeconomics. We ...Anomalies in decision over time (e.g., “hyperbolic time discounting”) and under risk (e.g., Allais paradox and hyperbolic probability discounting) have been attracting attention in behavioral and neuroeconomics. We have proposed that psychophysical time commonly explains anomalies in both decisions (Takahashi, 2011, Physica A;Takahashi et al., 2012, J Behav Econ & Finance). By adopting the q-exponential time and probability discounting models, our psychophysical and behavioral economic experiment confirmed that nonlinear distortion of psychophysical time is a common cause of the anomalies in decision both over time and under risk (i.e., intertemporal choice and decision under risk). Implications for psychophysical neuroeconomics and econophysics are discussed.展开更多
Original equipment manufacturers(OEM) have never been so important and powerful as it is today in garment manufacturing industry.The OEMsupplier's production decisions always have a great impact on the market perf...Original equipment manufacturers(OEM) have never been so important and powerful as it is today in garment manufacturing industry.The OEMsupplier's production decisions always have a great impact on the market performance and the profits of a garment brand manufacturer.With constrained capacity and multiply buyers,howto make reasonable production decisions is an urgent problem for OEMsuppliers.A price discount model with a single OEMsupplier and two buyers is proposed to deal with the problem.Based on this model,the OEMsupplier could satisfy buyers' demands and guarantee their profits as well through adjusting price and delivery frequency.A numerical example validates the validity of the model.展开更多
With the gradual completion of the split-share structure reform,private placement has gradually become the mainstream of refinancing. One of the points that the practical and theoretical circles are widely concerned a...With the gradual completion of the split-share structure reform,private placement has gradually become the mainstream of refinancing. One of the points that the practical and theoretical circles are widely concerned about is that the private placement price is often higher than the market price at the time of the private placement. High discounts are often accompanied by the transmission of benefits,and the increase in insider information will lead to the risk of a stock market crash? This paper intends to use the data of A-share listed companies from 2006 to 2015 to empirically study the relationship between the discount on private placements and the risk of stock market crash. At the same time,this paper examines whether the degree of information asymmetry plays a regulatory role in the relationship between the discount on private placements and the risk of stock market crash. This paper provides a certain reference for the regulatory authorities to improve the relevant laws and regulations in the private placement,and to provide a certain reference for the protection of the interests of small and medium-sized investors.展开更多
基金Supported by the National Natural Science Foundation of China(No.82371033No.81970772)+1 种基金the Tianjin Natural Science Foundation(No.21JCZDJC01250)the Tianjin Key Medical Discipline(Specialty)Construction Project(No.TJYXZDXK-016A).
文摘AIM:To analysis of research hotspots and trends on the application of premium intraocular lens(PIOLs)in the past 2 decades.METHODS:The literature search was performed on the Web of Science and included PIOLs studies published between January 2000 and December 2022.The retrieved literature was collated and analyzed by R-tool’s Bibliometrix package,CitNetExplorer,CiteSpace and other software.RESULTS:A total of 1801 articles about PIOLs were obtained,most of which were published in Spain and the United States.The organization that published the most articles was the University of Valencia in Spain.Alió JL,and Montés-Micó R,from Spain were the most influential authors in this field.The Journal of Cataract and Refractive Surgery and Journal of Refractive Surgery were the core journals for this field;the top 10 cited articles mainly focus on postoperative satisfaction with multifocal intraocular lens(IOLs)and postoperative results of toric IOLs.Through the keyword analysis,we found that trifocal IOLs,astigmatism and extended depth of focus(EDoF)IOLs are the most discussed topics at present,and the importance of astigmatism and the clinical application of the new generation of PIOLs are the emerging research trends.CONCLUSION:Bibliometric analysis can effectively help to identify multilevel concerns in PIOLs research and the prevailing research trends in the realm of PIOLs encompass the adoption of EDoF IOLs,trifocal IOLs,and their respective Toric models.
基金Supported by the Natural Science Foundation of Gansu Province,No.22JR5RN1054.
文摘BACKGROUND The role of physical activity in diabetes is critical,influencing this disease's development,man-agement,and overall outcomes.In China,22.3%of adults do not meet the minimum level of physical activity recommended by the World Health Organization.Therefore,it is imperative to identify the factors that contributing to lack of physical activity must be identified.AIM To investigate the relationship among delay discounting,delay aversion,glycated hemoglobin(HbA1c),and various levels of physical activity in Chinese adults diagnosed with type 2 diabetes mellitus(T2DM).METHODS In 2023,400 adults with T2DM were recruited from the People's Hospital of Linxia Hui Autonomous Prefecture of Gansu Province.A face-to-face questionnaire was used to gather demographic data and details on physical activity,delay discounting,and delay aversion.In addition,HbA1c levels were measured in all 400 participants.The primary independent variables considered were delay discounting and delay aversion.The outcome variables included HbA1c levels and different intensity levels of physical activity,including walking,moderate physical activity,and vigorous physical activity.Multiple linear regression models were utilized to assess the relationship between delay discounting,delay aversion,and HbA1c levels,along with the intensity of different physical activity measured in met-hours per week.RESULTS After controlling for the sample characteristics,delay discounting was negatively associated with moderate physical activity(β=-2.386,95%CI:-4.370 to-0.401).Meanwhile,delay aversion was negatively associated with the level of moderate physical activity(β=-3.527,95%CI:-5.578 to-1.476)in the multiple linear regression model,with statistically significant differences.CONCLUSION Elevated delay discounting and increased delay aversion correlated with reduced levels of moderate physical activity.Result suggests that delay discounting and aversion may influence engagement in moderate physical activity.This study recommends that health administration and government consider delay discounting and delay aversion when formulating behavioral intervention strategies and treatment guidelines involving physical activity for patients with T2DM,which may increase participation in physical activity.This study contributes a novel perspective to the research on physical activity in adults with T2DM by examining the significance of future health considerations and the role of emotional responses to delays.
文摘Reinsurance is an effective risk management tool for insurers to stabilize their profitability. In a typical reinsurance treaty, an insurer cedes part of the loss to a reinsurer. As the insurer faces an increasing number of total losses in the insurance market, the insurer might expect the reinsurer to bear an increasing proportion of the total loss, that is the insurer might expect the reinsurer to pay an increasing proportion of the total claim amount when he faces an increasing number of total claims in the insurance market. Motivated by this, we study the optimal reinsurance problem under the Vajda condition. To prevent moral hazard and reflect the spirit of reinsurance, we assume that the retained loss function is increasing and the ceded loss function satisfies the Vajda condition. We derive the explicit expression of the optimal reinsurance under the TVaR risk measure and TVaR premium principle from the perspective of both an insurer and a reinsurer. Our results show that the explicit expression of the optimal reinsurance is in the form of two or three interconnected line segments. Under an additional mild constraint, we get the optimal parameters and find the optimal reinsurance strategy is full reinsurance, no reinsurance, stop loss reinsurance, or quota-share reinsurance. Finally, we gave an example to analyze the impact of the weighting factor on optimal reinsurance.
文摘Traditional machine learning metrics(TMLMs)are quite useful for the current research work precision,recall,accuracy,MSE and RMSE.Not enough for a practitioner to be confident about the performance and dependability of innovative interpretable model 85%–92%.We included in the prediction process,machine learning models(MLMs)with greater than 99%accuracy with a sensitivity of 95%–98%and specifically in the database.We need to explain the model to domain specialists through the MLMs.Human-understandable explanations in addition to ML professionals must establish trust in the prediction of our model.This is achieved by creating a model-independent,locally accurate explanation set that makes it better than the primary model.As we know that human interaction with machine learning systems on this model’s interpretability is more crucial.For supporting set validations in model selection insurance premium prediction.In this study,we proposed the use of the(LIME and SHAP)approach to understand research properly and explain a model developed using random forest regression to predict insurance premiums.The SHAP algorithm’s drawback,as seen in our experiments,is its lengthy computing time—to produce the findings,it must compute every possible combination.In addition,the experiments conducted were intended to focus on the model’s interpretability and explain its ability using LIME and SHAP,not the insurance premium charge prediction.Three experiments were conducted through experiment,one was to interpret the random forest regression model using LIME techniques.In experiment 2,we used the SHAP technique to interpret the model insurance premium prediction(IPP).
基金The Achievements of Young Fund Project of Humanitiesand Social Science of Ministry of Education(No.07JC790028)the NationalNatural Science Foundation of China (No.70671025).
文摘The polynomial spline model, which belongs to the static term structure model of interest rates, is studied. Every cash flow of the project is discounted relatively accurately by obtaining the discount rate from the static term structure model of interest rates. A simple basic model, which belongs to the dynamic term structure model, is studied, and the option pricing formula under changing risk-free rates is obtained by bringing it into the option pricing formula. Both dynamic and static term structure models are estimated by the use of the data of buy-back rates and the Shanghai Stock Exchange, and an example is given to compare the differences between the traditional method and the method under the changes in the interest rates and the discount rates.
文摘This paper studied the effects of crop insurance on agricultural output with an economic growth model. Based on Ramsey-Cass-Koopmans (RCK) model, a basic model of agriculture economic growth was developed. Extending the basic model to incorporate uncertainty and insurance mechanism, a risk model and a risk-insurance model were built to study the inlfuences of risk and crop insurance on agricultural output. Compared with the steady states of the three models, the following results are achieved:(i) agricultural output decreases if we introduce uncertainty into the risk-free model;(ii) crop insurance promotes agriculture economic growth if insurance mechanism is introduced into the risk model;(iii) premium subsidy constantly improves agricultural output. Our contribution is that we studied the effects of crop insurance and premium subsidy from the perspective of economic growth in a dynamic framework, and proved the output promotion of crop insurance theoretically.
文摘We consider a risk model with a premium rate which varies with the level of free reserves. In this model, the occurrence of claims is described by a Cox process with Markov intensity process, and the influence of stochastic factors is considered by adding a diffusion process. The integro-differential equation for the ruin probability is derived by a infinitesimal method. Key words ruin probability - variable premium rate - diffusion process - Markov intensity CLC number O 211.9 Foundation item: Supported by the National Natural Science Foundation of China (10071058, 70273029)
文摘In this present paper, a deterministic lot size model is developed for deteriorating items with incremental quantity discounts. It is assumed that shortages are permitted to occur and fully backlogged. A simple solution procedure is shown for determining the optimal order lot size and the optimal order cycle. A numerical example is used to illustrate how the solution procedure works.
文摘Probability discounting is defined as the devaluation of outcomes as the probability of receiving or paying those decreases. A q-exponential probability discounting model based on Tsallis’ statistics has been proposed in econophysics (Takahashi, 2007, Physica A). We examined (a) fitness of the models to behavioral data of probability discounting of both gain and loss;and (b) relationships between parameters in the q-exponential probability discounting model across gain and loss. Our results demonstrated that, for both gain and loss, the q-exponential model better fits the behavioral data than exponential and hyperbolic functions, and there is the sign effect in q-exponential probability discounting. Relationships between Kahneman-Tversky’s prospect theory in behavioral economics and the q-exponential probability discounting are high-lightened.
文摘Social discounting has been attracting attention in behavioral psychology, econophysics, and neuroeconomics. Several mathematical models have been proposed for social discounting;exponential discounting, hyperbolic discounting, a q-exponential discounting model based on Tsallis’ statistics. In order to experimentally examine the mathematical characteristics of the q-exponential social discounting models for gain and loss in humans, we estimated the parameters of the q-exponential social discounting models by assessing the points of subjective equality (indifference points) at seven social distances. We observed that gain was more steeply social-discounted than loss. Usefulness of the q-exponential social discounting model in social physics, econophysics, and cultural neuroeconomics are discussed.
文摘In order to analyze the sealing performance of a new designed premium threaded connection,this paper studies the sealing reliability and sensitivity of the premium threaded connection at its most dangerous load condition based on Kriging model.The load condition of premium threaded connection in deep well is so complex that the most dangerous load point of premium threaded connection under the typical series loads is studied by finite element analysis(FEA) method firstly.Since the FEA of the premium threaded connection is too time-consuming,Kriging model which is accurate and efficient for multidimensional and highly nonlinear problems is built to calculate the sealing reliability of the premium threaded connection at the most dangerous load point.Finally,the sealing sensitivity analysis of the premium threaded connection is performed by the method of variance-based global sensitivity analysis.The work in this paper could contribute for the analysis and further improvement of the premium threaded connection.
基金supported by NSFC National Outstanding Youth Science Foundation of China (Grant No.71103111)MOST Special Project of Innovative Methodology (Grant No.2012IM010300)Twelfth Five-Year National Science and Technology Support Program (Grant No.2012BAC20B01)
文摘This paper has organized and summarized the economic analysis on climate change from five angles,namely,connotation of discount rate,identification of and dispute about discount rate,discounting way,impact of the discount rate,and the integrated evaluation model of climate change impact and the discount evaluation.As the climate change economic analysis shows,there is a major dispute about discount rate between the market school and the ethic school.Rate of discount largely relates to the present value of potential loss attributable to climate change,and then influences the selection of policies for adapting and slowing down climate change.In the past,the constant index discount was adopted as the main way.But with the full understanding of discount rate,the uncertainty of loss attributable to climate change has been considered in the discount.
文摘This study examines the pricing of municipal bonds before and after a currency shock in Switzerland.Two approaches are used to decompose the municipal to treasuries bond spreads into liquidity,maturity,and default risk premiums.The first approach is the model of the cross-sectional instrumental variables,and the second approach is the model of the instrumental variables with panel data.This study examines the composition of spreads for both approaches,in three scenarios:before,throughout,and after the currency shock.The study performed Durbin-Wu-Hausman tests for each decisive model to verify endogeneity issues,including the Lagrangian Multiplier test,the Cragg-Donald Wald F statistic to confirm the relationship of instrumental and endogenous variables,and the structural break test(Bai-Perron test)to determine the existence of structural breaks in bond distortions.This study finds that the currency price distortions of the Swiss franc in January 2015 made long-run changes in the composition of the municipal bond spreads.This research contributes to the understanding of municipal bond pricing by showing that default risk accounts for a large portion of the municipal bond spread,while maturity risk plays a lesser role.According to our empirical findings,unexpected large currency price shocks may have long-term implications on the municipal bond spreads.
基金supported by the 12th Five Year National Key Technologies R&D Program of China[2012BAC20B05]
文摘Solving the dispute over historical greenhouse gases emission responsibility is critical for the future climate agreement.This article borrows the methodology from the carbon budget proposal,but further develops this approach by proposing discount of the historical responsibility due to the technology advance.Firstly,it studies the Annex I countries'mitigation and financial responsibilities of the historical emission in the carbon budget proposal;furthermore,it analyzes the results and implications of the discount approach.Results show that the discount method significantly reduces the burden of the mitigation and financial responsibilities of the Annex I countries.Thus,we claim that the discount approach is a systematic,pragmatic,and fair approach to solve the historical responsibility dispute and financial problems for the post-2020international climate institutions.
基金The National Natural Science Foundation of China (No.70671021)Jiangsu Postdoctoral Foundation (No.0601015C)
文摘The quantity discount contracts are investigated for a one-supplier-one-retailer supply chain with asymmetric information when the retailer's cost is disrupted. While the retailer's cost structure is asymmetric information, two all-unit quantity discount contract models, fixed expected-profit percentage discount(FEPD) and fixed wholesale-pricing percentage discount(FWPD) under asymmetric information are proposed in a regular scenario. When the retailer's cost distribution fluctuates due to disruptions, the optimal emergency strategies of supply chains are obtained under asymmetric information. Using numerical methods, the impact of cost disruptions on decisions about the regular wholesale price, discount wholesale price, order quantity and expected profits of the retailer, the supplier as well as the total system are analyzed. It is found that the FEPD policy is more robust and adaptable than the FWPD policy in disruption circumstances.
文摘Agriculture plays a vital role in the growth and development of the High Plains Region of the United States. With the development and adoption of irrigation technology, this region was transformed into one of the most agriculturally productive regions in the world [1]. The primary source of irrigation in this region is the Ogallala Aquifer. Currently, water from the aquifer is being used at a much faster rate than natural recharge can occur, resulting in a high rate of depletion from this finite resource. Depletion of scarce water resources will have a significant economic impact on the long-term sustainability of the region. The objective of this study is to evaluate the impact alternative prices and discount rates have on groundwater policy recommendations. Deterministic models of groundwater withdrawals were developed and used in order to analyze and evaluate the impact of high, average, and low crop prices in a status quo scenario as well as a policy scenario reducing irrigated acreage allocation. Furthermore, this study analyzes the effects and associated consequences of alternative discount rates on net and total revenue. As indicated by results of this study, alternative prices, costs, and discount rates utilized in a model have an effect on policy effectiveness.
基金Supported by National Excellent Doctoral Dissertation Cultivation Fund Project,Hunan Agricultural University (GYB201003)
文摘First,using the law of large numbers,I analyze the setting principle of agricultural insurance premium rate,and take the case of setting of adult sow premium rate for study,to draw the conclusion that with the continuous promotion of agricultural insurance,increase in the types of agricultural insurance and increase in the number of the insured,the premium rate should also be adjusted opportunely.Then,on the basis of Bayes' theorem,I adjust and calibrate the claim frequency and the average claim,in order to correctly adjust agricultural insurance premium rate;take the case of forest insurance for premium rate adjustment analysis.In setting and adjustment of agricultural insurance premium rate,in order to make the expected results well close to the real results,it is necessary to apply the probability estimates in a large number of risk units;focus on the establishment of agricultural risk database,to timely adjust agricultural insurance premium rate.
文摘Anomalies in decision over time (e.g., “hyperbolic time discounting”) and under risk (e.g., Allais paradox and hyperbolic probability discounting) have been attracting attention in behavioral and neuroeconomics. We have proposed that psychophysical time commonly explains anomalies in both decisions (Takahashi, 2011, Physica A;Takahashi et al., 2012, J Behav Econ & Finance). By adopting the q-exponential time and probability discounting models, our psychophysical and behavioral economic experiment confirmed that nonlinear distortion of psychophysical time is a common cause of the anomalies in decision both over time and under risk (i.e., intertemporal choice and decision under risk). Implications for psychophysical neuroeconomics and econophysics are discussed.
基金Innovative Methods of Science and Technology of China(No.SQ2015IM3600021)Tianjin Planning Office of Philosophy and Social Science,China(No.TJGL16-019)
文摘Original equipment manufacturers(OEM) have never been so important and powerful as it is today in garment manufacturing industry.The OEMsupplier's production decisions always have a great impact on the market performance and the profits of a garment brand manufacturer.With constrained capacity and multiply buyers,howto make reasonable production decisions is an urgent problem for OEMsuppliers.A price discount model with a single OEMsupplier and two buyers is proposed to deal with the problem.Based on this model,the OEMsupplier could satisfy buyers' demands and guarantee their profits as well through adjusting price and delivery frequency.A numerical example validates the validity of the model.
文摘With the gradual completion of the split-share structure reform,private placement has gradually become the mainstream of refinancing. One of the points that the practical and theoretical circles are widely concerned about is that the private placement price is often higher than the market price at the time of the private placement. High discounts are often accompanied by the transmission of benefits,and the increase in insider information will lead to the risk of a stock market crash? This paper intends to use the data of A-share listed companies from 2006 to 2015 to empirically study the relationship between the discount on private placements and the risk of stock market crash. At the same time,this paper examines whether the degree of information asymmetry plays a regulatory role in the relationship between the discount on private placements and the risk of stock market crash. This paper provides a certain reference for the regulatory authorities to improve the relevant laws and regulations in the private placement,and to provide a certain reference for the protection of the interests of small and medium-sized investors.