In this paper, we establish properties for the switch-when-safe mean-variance strategies in the context of a Black-Scholes market model with stochastic volatility processes driven by a continuous-time Markov chain wit...In this paper, we establish properties for the switch-when-safe mean-variance strategies in the context of a Black-Scholes market model with stochastic volatility processes driven by a continuous-time Markov chain with a finite number of states. More precisely, expressions for the goal-achieving probabilities of the terminal wealth are obtained and numerical comparisons of lower bounds for these probabilities are shown for various market parameters. We conclude with asymptotic results when the Markovian changes in the volatility parameters appear with either higher or lower frequencies.展开更多
This article focuses on the challenges of rural economic development under the strategy of rural revitalization,and deeply analyzes the current situation of rural economic development.Research has found that although ...This article focuses on the challenges of rural economic development under the strategy of rural revitalization,and deeply analyzes the current situation of rural economic development.Research has found that although the rural revitalization strategy has achieved significant results in improving residents’quality of life,promoting agricultural modernization,it still faces challenges such as severe loss of human resources,insufficient agricultural technological innovation,and backward infrastructure construction.In response to these challenges,this paper proposes optimization strategies from three aspects:strengthening rural education and talent team construction,promoting agricultural technology innovation and achievement transformation,and increasing investment in rural infrastructure construction.展开更多
Ischemic stroke is a major cause of neurological deficits and high disability rate.As the primary immune cells of the central nervous system,microglia play dual roles in neuroinflammation and tissue repair following a...Ischemic stroke is a major cause of neurological deficits and high disability rate.As the primary immune cells of the central nervous system,microglia play dual roles in neuroinflammation and tissue repair following a stroke.Their dynamic activation and polarization states are key factors that influence the disease process and treatment outcomes.This review article investigates the role of microglia in ischemic stroke and explores potential intervention strategies.Microglia exhibit a dynamic functional state,transitioning between pro-inflammatory(M1)and anti-inflammatory(M2)phenotypes.This duality is crucial in ischemic stroke,as it maintains a balance between neuroinflammation and tissue repair.Activated microglia contribute to neuroinflammation through cytokine release and disruption of the blood-brain barrier,while simultaneously promoting tissue repair through anti-inflammatory responses and regeneration.Key pathways influencing microglial activation include Toll-like receptor 4/nuclear factor kappa B,mitogen-activated protein kinases,Janus kinase/signal transducer and activator of transcription,and phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathways.These pathways are targets for various experimental therapies aimed at promoting M2 polarization and mitigating damage.Potential therapeutic agents include natural compounds found in drugs such as minocycline,as well as traditional Chinese medicines.Drugs that target these regulatory mechanisms,such as small molecule inhibitors and components of traditional Chinese medicines,along with emerging technologies such as single-cell RNA sequencing and spatial transcriptomics,offer new therapeutic strategies and clinical translational potential for ischemic stroke.展开更多
We establish, through solving semi-infinite programming problems, bounds on the probability of safely reaching a desired level of wealth on a finite horizon, when an investor starts with an optimal mean-variance finan...We establish, through solving semi-infinite programming problems, bounds on the probability of safely reaching a desired level of wealth on a finite horizon, when an investor starts with an optimal mean-variance financial investment strategy under a non-negative wealth restriction.展开更多
Dove’s 2017 advertising incident,which sparked widespread debate regarding perceived cultural insensitivity,highlighted a disconnect between the brand’s“Real Beauty”positioning and public reception.In response,thi...Dove’s 2017 advertising incident,which sparked widespread debate regarding perceived cultural insensitivity,highlighted a disconnect between the brand’s“Real Beauty”positioning and public reception.In response,this study proposes a strategic digital recovery framework,including revised campaign content,transparent communication through social media,and data-driven customer segmentation based on diverse skincare needs and cultural backgrounds.A PESTLE analysis underscores the importance of digital transformation and rising social consciousness in brand management.Findings suggest that inclusive messaging,precision targeting,and omnichannel digital engagement are key to restoring brand trust and reputation in the digital landscape.展开更多
Neural injuries can cause considerable functional impairments,and both central and peripheral nervous systems have limited regenerative capacity.The existing conventional pharmacological treatments in clinical practic...Neural injuries can cause considerable functional impairments,and both central and peripheral nervous systems have limited regenerative capacity.The existing conventional pharmacological treatments in clinical practice show poor targeting,rapid drug clearance from the circulatory system,and low therapeutic efficiency.Therefore,in this review,we have first described the mechanisms underlying nerve regeneration,characterized the biomaterials used for drug delivery to facilitate nerve regeneration,and highlighted the functionalization strategies used for such drug-delivery systems.These systems mainly use natural and synthetic polymers,inorganic materials,and hybrid systems with advanced drug-delivery abilities,including nanoparticles,hydrogels,and scaffoldbased systems.Then,we focused on comparing the types of drug-delivery systems for neural regeneration as well as the mechanisms and challenges associated with targeted delivery of drugs to facilitate neural regeneration.Finally,we have summarized the clinical application research and limitations of targeted delivery of these drugs.These biomaterials and drug-delivery systems can provide mechanical support,sustained release of bioactive molecules,and enhanced intercellular contact,ultimately reducing cell apoptosis and enhancing functional recovery.Nevertheless,immune reactions,degradation regulation,and clinical translations remain major unresolved challenges.Future studies should focus on optimizing biomaterial properties,refining delivery precision,and overcoming translational barriers to advance these technologies toward clinical applications.展开更多
Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespr...Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespread attention for CO_(2)RR due to their high catalytic activity,selectivity,excellent stability,and low cost.However,they still need to be further improved to meet the needs of industrial applications.This review article comprehensively summarizes the recent advances in regulation strategies of Bi-based catalysts and can be divided into six categories:(1)defect engineering,(2)atomic doping engineering,(3)organic framework engineering,(4)inorganic heterojunction engineering,(5)crystal face engineering,and(6)alloying and polarization engineering.Meanwhile,the corresponding catalytic mechanisms of each regulation strategy will also be discussed in detail,aiming to enable researchers to understand the structure-property relationship of the improved Bibased catalysts fundamentally.Finally,the challenges and future opportunities of the Bi-based catalysts in the photoelectrocatalytic CO_(2)RR application field will also be featured from the perspectives of the(1)combination or synergy of multiple regulatory strategies,(2)revealing formation mechanism and realizing controllable synthesis,and(3)in situ multiscale investigation of activation pathways and uncovering the catalytic mechanisms.On the one hand,through the comparative analysis and mechanism explanation of the six major regulatory strategies,a multidimensional knowledge framework of the structure-activity relationship of Bi-based catalysts can be constructed for researchers,which not only deepens the atomic-level understanding of catalytic active sites,charge transport paths,and the adsorption behavior of intermediate products,but also provides theoretical guiding principles for the controllable design of new catalysts;on the other hand,the promising collaborative regulation strategies,controllable synthetic paths,and the in situ multiscale characterization techniques presented in this work provides a paradigm reference for shortening the research and development cycle of high-performance catalysts,conducive to facilitating the transition of photoelectrocatalytic CO_(2)RR technology from the laboratory routes to industrial application.展开更多
In this paper, we consider an insurance company which has the option of investing in a risky asset and a risk-free asset, whose price parameters are driven by a finite state Markov chain. The risk process of the insur...In this paper, we consider an insurance company which has the option of investing in a risky asset and a risk-free asset, whose price parameters are driven by a finite state Markov chain. The risk process of the insurance company is modeled as a diffusion process whose diffusion and drift parameters switch over time according to the same Markov chain. We study the Markov-modulated mean-variance problem for the insurer and derive explicitly the closed form of the efficient strategy and efficient frontier. In the case of no regime switching, we can see that the efficient frontier in our paper coincides with that of [10] when there is no pure jump.展开更多
Assuming the investor is uncertainty-aversion,the multiprior approach is applied to studying the problem of portfolio choice under the uncertainty about the expected return of risky asset based on the mean-variance mo...Assuming the investor is uncertainty-aversion,the multiprior approach is applied to studying the problem of portfolio choice under the uncertainty about the expected return of risky asset based on the mean-variance model. By introducing a set of constraint constants to measure uncertainty degree of the estimated expected return,it built the max-min model of multi-prior portfolio,and utilized the Lagrange method to obtain the closed-form solution of the model,which was compared with the mean-variance model and the minimum-variance model; then,an empirical study was done based on the monthly returns over the period June 2011 to May 2014 of eight kinds of stocks in Shanghai Exchange 50 Index. Results showed,the weight of multi-prior portfolio was a weighted average of the weight of mean-variance portfolio and that of minimumvariance portfolio; the steady of multi-prior portfolio was strengthened compared with the mean-variance portfolio; the performance of multi-prior portfolio was greater than that of minimum-variance portfolio. The study demonstrates that the investor can improve the steady of multi-prior portfolio as well as its performance for some appropriate constraint constants.展开更多
Social capital in the form of social resources or social networks is one of the most important livelihood capital of farmers, which can increase the labor productivity of poor households and increase income. It is imp...Social capital in the form of social resources or social networks is one of the most important livelihood capital of farmers, which can increase the labor productivity of poor households and increase income. It is important to explore the reasons underlying the livelihood strategy choices of farmers from the perspective of social capital under China’s rural revitalization strategy. In this study, the Liangshan Yi Autonomous Prefecture, a povertystricken mountainous area in southwestern China, was selected as the case study area, and multivariable linear regression models were constructed to analyze the influence of social capital on livelihood strategies.The results are as follows:(1) Individual social capital had a positive effect on non-agricultural livelihood strategies. On average, with a one-unit increase in individual social capital, the ratio of farmers’ nonagricultural income to total productive income(Income_Rto) increased by 0.002% and 0.062%,respectively. Collective social capital, with the Peasant Economic Cooperation Organization(PECO) as the carrier, had a negative effect on the non-agricultural livelihood strategies of farmers;on average, with a oneunit increase in PECO, Income_Rto decreased by approximately 0.053%. However, this effect was only significant in the river valley area.(2) The income differences among the different livelihood strategy types were explained by the livelihood strategy choices of farmers. As non-agricultural work can bring more benefits, the labor force exhibited one-way migration from villages to cities, resulting in a lack of the subject of rural revitalization. It is necessary to implement effective measures to highlight the role of PECO in increasing agricultural income for farmers. Finally,based on the above conclusions,policy recommendations with respect to livelihood transformation of farmers and rural sustainable development are discussed.展开更多
In this paper, we focus on a constant elasticity of variance （CEV） modeland want to find its optimal strategies for a mean-variance problem under two constrainedcontrols： reinsurance/new business and investment （n...In this paper, we focus on a constant elasticity of variance （CEV） modeland want to find its optimal strategies for a mean-variance problem under two constrainedcontrols： reinsurance/new business and investment （no-shorting）. First, aLagrange multiplier is introduced to simplify the mean-variance problem and thecorresponding Hamilton-Jacobi-Bellman （HJB） equation is established. Via a powertransformation technique and variable change method, the optimal strategies withthe Lagrange multiplier are obtained. Final, based on the Lagrange duality theorem,the optimal strategies and optimal value for the original problem （i.e., the efficientstrategies and efficient frontier） are derived explicitly.展开更多
This paper considered the problem of hedging a European call (put) option for a diffusion model where the asset price is influenced by n uncertain factors. The market is thus incomplete implying that perfect hedging i...This paper considered the problem of hedging a European call (put) option for a diffusion model where the asset price is influenced by n uncertain factors. The market is thus incomplete implying that perfect hedging is not possible. To derive a hedging strategy, it follows the approach based on the idea of hedging under a mean-variance criterion suggested by Schweizer. A very simple solution of this hedging problem by using the numeraire method was presented and some examples with explicit solutions were given.展开更多
Since confidence is fading and anxiety is increasing in the US,America’s China policy has become more radical. In the short term, the US has the upper hand and China is in a relatively passive position. In the medium...Since confidence is fading and anxiety is increasing in the US,America’s China policy has become more radical. In the short term, the US has the upper hand and China is in a relatively passive position. In the medium-and long-term, there will be more balance between them. This current strategic gambling between China and the US will be the major issue of international politics in the first half of the 21 st century and the most prominent external challenge China faces. China needs to make strategic adjustments but the gamble may be worthwhile in correcting imbalance in the international order and in the co-evolution of the two countries.展开更多
With the entry to WTO and development of IT, banks in China are adjusting their competitive strategies to meet the competition. Internet banking has become a kind of strategic choice to response to the entry to WTO. B...With the entry to WTO and development of IT, banks in China are adjusting their competitive strategies to meet the competition. Internet banking has become a kind of strategic choice to response to the entry to WTO. Based on relevantly selective reviews of literature of strategy theory and research, a model is developed to study banks' strategic response to entry to WTO. According to a survey of 192 sets of questionnaires, this study finds that external pressure, business strategy and perceived benefits of Internet banking would influence banks' perceived increase in Internet banking investment. And banks' perceived increase in Internet banking investment has no difference between big banks and small banks.展开更多
Building a technology alliance is the main strategy for the United States to maintain its scientific and technological hegemony under its technopolitical strategic framework.After Joe Biden took office,the United Stat...Building a technology alliance is the main strategy for the United States to maintain its scientific and technological hegemony under its technopolitical strategic framework.After Joe Biden took office,the United States implemented“small yard with high fences”strategy for scientific and technological competition,as the first step toward building a technology alliance.The main goal is to restrict the flow of strategic emerging technologies and factors of innovation to rival countries.展开更多
Aiming to reveal the university students＇ understanding in management as for the strategy and strategic management phenomena, this study accomplishes a phenomenographic research to assess the future managers＇ market...Aiming to reveal the university students＇ understanding in management as for the strategy and strategic management phenomena, this study accomplishes a phenomenographic research to assess the future managers＇ market perception. It was chosen university students in Management of a Portuguese University. We conclude that the strategy definitions obtained are an assembly of the diverse existing concepts. Concerning to strategic management it was perceived an approach with one of the main existing concepts. The findings raise interesting issues with respect to the difficulties felt by new managers in translating their theoretical definitions in real examples in the organizations.展开更多
The key argument of this conceptual paper is that the roots of a viable future for an organisation are found in a robust strategic architecture perspective.The theoretical baselines for the concepts associated with th...The key argument of this conceptual paper is that the roots of a viable future for an organisation are found in a robust strategic architecture perspective.The theoretical baselines for the concepts associated with this paper are linked to a variety of strategy theories.These include,but are not restricted to,institutional theory,strategic thinking relating to the positioning-based view(PBV)and resource-based view(RBV)respectively,entrepreneurial thinking,and innovation thinking.Strategy can be described as the collective,emerging pattern—based on strategic choices—an organisation consciously exhibits and executes over time to ensure its sustainable endurance by differentiating itself in unique ways to create and add value for stakeholders.Strategy is about explaining how an organisation wants to move forward and how it wants to advance the interests of stakeholders.A strategic landscape is the broad external and internal context of an organisation.An important part of strategy and the strategic landscape it operates in is how organisations define or“construct”their own“topography”or strategic architecture.A strategic architecture presents an organisation?s core logic for creating sustainable value,and therefore,forms the foundation of an organisation?s competitive potential in a specific context.This paper presents descriptions of the seven key buildings blocks that constitute a strategic architecture perspective for an organisation with an indication of strategy tools and frameworks that can be used to illuminate strategic possibilities,choices,and challenges to assist ongoing strategising praxis.The key features and assumptions associated with a strategic architecture perspective are discussed.A strategic architecture perspective assists leaders to work through the strategic complexity to arrive at simplicity in the form of clarity on external and internal strategic leverages,strategic aspirations,core strategic choices,plausible multiple scenarios,focused strategic goals,and success measurements to guide strategy execution and ongoing strategy renewal and innovations for proactive strategic decision-making through various dialogues with key stakeholders.展开更多
Present of wind power is sporadically and cannot be utilized as the only fundamental load of energy sources.This paper proposes a wind-solar hybrid energy storage system(HESS)to ensure a stable supply grid for a longe...Present of wind power is sporadically and cannot be utilized as the only fundamental load of energy sources.This paper proposes a wind-solar hybrid energy storage system(HESS)to ensure a stable supply grid for a longer period.A multi-objective genetic algorithm(MOGA)and state of charge(SOC)region division for the batteries are introduced to solve the objective function and configuration of the system capacity,respectively.MATLAB/Simulink was used for simulation test.The optimization results show that for a 0.5 MW wind power and 0.5 MW photovoltaic system,with a combination of a 300 Ah lithium battery,a 200 Ah lead-acid battery,and a water storage tank,the proposed strategy reduces the system construction cost by approximately 18,000 yuan.Additionally,the cycle count of the electrochemical energy storage systemincreases from4515 to 4660,while the depth of discharge decreases from 55.37%to 53.65%,achieving shallow charging and discharging,thereby extending battery life and reducing grid voltage fluctuations significantly.The proposed strategy is a guide for stabilizing the grid connection of wind and solar power generation,capability allocation,and energy management of energy conservation systems.展开更多
文摘In this paper, we establish properties for the switch-when-safe mean-variance strategies in the context of a Black-Scholes market model with stochastic volatility processes driven by a continuous-time Markov chain with a finite number of states. More precisely, expressions for the goal-achieving probabilities of the terminal wealth are obtained and numerical comparisons of lower bounds for these probabilities are shown for various market parameters. We conclude with asymptotic results when the Markovian changes in the volatility parameters appear with either higher or lower frequencies.
文摘This article focuses on the challenges of rural economic development under the strategy of rural revitalization,and deeply analyzes the current situation of rural economic development.Research has found that although the rural revitalization strategy has achieved significant results in improving residents’quality of life,promoting agricultural modernization,it still faces challenges such as severe loss of human resources,insufficient agricultural technological innovation,and backward infrastructure construction.In response to these challenges,this paper proposes optimization strategies from three aspects:strengthening rural education and talent team construction,promoting agricultural technology innovation and achievement transformation,and increasing investment in rural infrastructure construction.
基金supported by the National Natural Science Foundation of China,82471345(to LC)the Key Research and Development Program for Social Development by the Jiangsu Provincial Department of Science and Technology.No.BE2022668(to LC).
文摘Ischemic stroke is a major cause of neurological deficits and high disability rate.As the primary immune cells of the central nervous system,microglia play dual roles in neuroinflammation and tissue repair following a stroke.Their dynamic activation and polarization states are key factors that influence the disease process and treatment outcomes.This review article investigates the role of microglia in ischemic stroke and explores potential intervention strategies.Microglia exhibit a dynamic functional state,transitioning between pro-inflammatory(M1)and anti-inflammatory(M2)phenotypes.This duality is crucial in ischemic stroke,as it maintains a balance between neuroinflammation and tissue repair.Activated microglia contribute to neuroinflammation through cytokine release and disruption of the blood-brain barrier,while simultaneously promoting tissue repair through anti-inflammatory responses and regeneration.Key pathways influencing microglial activation include Toll-like receptor 4/nuclear factor kappa B,mitogen-activated protein kinases,Janus kinase/signal transducer and activator of transcription,and phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathways.These pathways are targets for various experimental therapies aimed at promoting M2 polarization and mitigating damage.Potential therapeutic agents include natural compounds found in drugs such as minocycline,as well as traditional Chinese medicines.Drugs that target these regulatory mechanisms,such as small molecule inhibitors and components of traditional Chinese medicines,along with emerging technologies such as single-cell RNA sequencing and spatial transcriptomics,offer new therapeutic strategies and clinical translational potential for ischemic stroke.
文摘We establish, through solving semi-infinite programming problems, bounds on the probability of safely reaching a desired level of wealth on a finite horizon, when an investor starts with an optimal mean-variance financial investment strategy under a non-negative wealth restriction.
文摘Dove’s 2017 advertising incident,which sparked widespread debate regarding perceived cultural insensitivity,highlighted a disconnect between the brand’s“Real Beauty”positioning and public reception.In response,this study proposes a strategic digital recovery framework,including revised campaign content,transparent communication through social media,and data-driven customer segmentation based on diverse skincare needs and cultural backgrounds.A PESTLE analysis underscores the importance of digital transformation and rising social consciousness in brand management.Findings suggest that inclusive messaging,precision targeting,and omnichannel digital engagement are key to restoring brand trust and reputation in the digital landscape.
基金the support from Base for Interdisciplinary Innovative Talent Training,Shanghai Jiao Tong UniversityYouth Science and Technology Innovation Studio of Shanghai Jiao Tong University School of Medicine。
文摘Neural injuries can cause considerable functional impairments,and both central and peripheral nervous systems have limited regenerative capacity.The existing conventional pharmacological treatments in clinical practice show poor targeting,rapid drug clearance from the circulatory system,and low therapeutic efficiency.Therefore,in this review,we have first described the mechanisms underlying nerve regeneration,characterized the biomaterials used for drug delivery to facilitate nerve regeneration,and highlighted the functionalization strategies used for such drug-delivery systems.These systems mainly use natural and synthetic polymers,inorganic materials,and hybrid systems with advanced drug-delivery abilities,including nanoparticles,hydrogels,and scaffoldbased systems.Then,we focused on comparing the types of drug-delivery systems for neural regeneration as well as the mechanisms and challenges associated with targeted delivery of drugs to facilitate neural regeneration.Finally,we have summarized the clinical application research and limitations of targeted delivery of these drugs.These biomaterials and drug-delivery systems can provide mechanical support,sustained release of bioactive molecules,and enhanced intercellular contact,ultimately reducing cell apoptosis and enhancing functional recovery.Nevertheless,immune reactions,degradation regulation,and clinical translations remain major unresolved challenges.Future studies should focus on optimizing biomaterial properties,refining delivery precision,and overcoming translational barriers to advance these technologies toward clinical applications.
基金supports from the National Natural Science Foundation of China(Grant Nos.12305372 and 22376217)the National Key Research&Development Program of China(Grant Nos.2022YFA1603802 and 2022YFB3504100)+1 种基金the projects of the key laboratory of advanced energy materials chemistry,ministry of education(Nankai University)key laboratory of Jiangxi Province for persistent pollutants prevention control and resource reuse(2023SSY02061)are gratefully acknowledged.
文摘Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespread attention for CO_(2)RR due to their high catalytic activity,selectivity,excellent stability,and low cost.However,they still need to be further improved to meet the needs of industrial applications.This review article comprehensively summarizes the recent advances in regulation strategies of Bi-based catalysts and can be divided into six categories:(1)defect engineering,(2)atomic doping engineering,(3)organic framework engineering,(4)inorganic heterojunction engineering,(5)crystal face engineering,and(6)alloying and polarization engineering.Meanwhile,the corresponding catalytic mechanisms of each regulation strategy will also be discussed in detail,aiming to enable researchers to understand the structure-property relationship of the improved Bibased catalysts fundamentally.Finally,the challenges and future opportunities of the Bi-based catalysts in the photoelectrocatalytic CO_(2)RR application field will also be featured from the perspectives of the(1)combination or synergy of multiple regulatory strategies,(2)revealing formation mechanism and realizing controllable synthesis,and(3)in situ multiscale investigation of activation pathways and uncovering the catalytic mechanisms.On the one hand,through the comparative analysis and mechanism explanation of the six major regulatory strategies,a multidimensional knowledge framework of the structure-activity relationship of Bi-based catalysts can be constructed for researchers,which not only deepens the atomic-level understanding of catalytic active sites,charge transport paths,and the adsorption behavior of intermediate products,but also provides theoretical guiding principles for the controllable design of new catalysts;on the other hand,the promising collaborative regulation strategies,controllable synthetic paths,and the in situ multiscale characterization techniques presented in this work provides a paradigm reference for shortening the research and development cycle of high-performance catalysts,conducive to facilitating the transition of photoelectrocatalytic CO_(2)RR technology from the laboratory routes to industrial application.
基金supported by National Basic Research Program of China(973 Program)(2007CB814905)the National Natural Science Foundation of China(10871102)the Research Fund for the Doctorial Program of Higher Education
文摘In this paper, we consider an insurance company which has the option of investing in a risky asset and a risk-free asset, whose price parameters are driven by a finite state Markov chain. The risk process of the insurance company is modeled as a diffusion process whose diffusion and drift parameters switch over time according to the same Markov chain. We study the Markov-modulated mean-variance problem for the insurer and derive explicitly the closed form of the efficient strategy and efficient frontier. In the case of no regime switching, we can see that the efficient frontier in our paper coincides with that of [10] when there is no pure jump.
基金National Natural Science Foundations of China(Nos.71271003,71171003)Programming Fund Project of the Humanities and Social Sciences Research of the Ministry of Education of China(No.12YJA790041)
文摘Assuming the investor is uncertainty-aversion,the multiprior approach is applied to studying the problem of portfolio choice under the uncertainty about the expected return of risky asset based on the mean-variance model. By introducing a set of constraint constants to measure uncertainty degree of the estimated expected return,it built the max-min model of multi-prior portfolio,and utilized the Lagrange method to obtain the closed-form solution of the model,which was compared with the mean-variance model and the minimum-variance model; then,an empirical study was done based on the monthly returns over the period June 2011 to May 2014 of eight kinds of stocks in Shanghai Exchange 50 Index. Results showed,the weight of multi-prior portfolio was a weighted average of the weight of mean-variance portfolio and that of minimumvariance portfolio; the steady of multi-prior portfolio was strengthened compared with the mean-variance portfolio; the performance of multi-prior portfolio was greater than that of minimum-variance portfolio. The study demonstrates that the investor can improve the steady of multi-prior portfolio as well as its performance for some appropriate constraint constants.
基金financial supports from the National Natural Science Foundation of China (Grant Nos. 41461040, 41601614, 41601176)the Fundamental Research Funds for the Central Universities (JBK2102018)the Sichuan Center for Rural Development Research (CR2107, Mechanism of Farmers’ Livelihoods on Ecological Security in Ethnic Regions in Sichuan Province)。
文摘Social capital in the form of social resources or social networks is one of the most important livelihood capital of farmers, which can increase the labor productivity of poor households and increase income. It is important to explore the reasons underlying the livelihood strategy choices of farmers from the perspective of social capital under China’s rural revitalization strategy. In this study, the Liangshan Yi Autonomous Prefecture, a povertystricken mountainous area in southwestern China, was selected as the case study area, and multivariable linear regression models were constructed to analyze the influence of social capital on livelihood strategies.The results are as follows:(1) Individual social capital had a positive effect on non-agricultural livelihood strategies. On average, with a one-unit increase in individual social capital, the ratio of farmers’ nonagricultural income to total productive income(Income_Rto) increased by 0.002% and 0.062%,respectively. Collective social capital, with the Peasant Economic Cooperation Organization(PECO) as the carrier, had a negative effect on the non-agricultural livelihood strategies of farmers;on average, with a oneunit increase in PECO, Income_Rto decreased by approximately 0.053%. However, this effect was only significant in the river valley area.(2) The income differences among the different livelihood strategy types were explained by the livelihood strategy choices of farmers. As non-agricultural work can bring more benefits, the labor force exhibited one-way migration from villages to cities, resulting in a lack of the subject of rural revitalization. It is necessary to implement effective measures to highlight the role of PECO in increasing agricultural income for farmers. Finally,based on the above conclusions,policy recommendations with respect to livelihood transformation of farmers and rural sustainable development are discussed.
基金The NSF(11201111) of ChinaHebei Province Colleges and Universities Science,and Technology Research Project(ZD20131017)
文摘In this paper, we focus on a constant elasticity of variance （CEV） modeland want to find its optimal strategies for a mean-variance problem under two constrainedcontrols： reinsurance/new business and investment （no-shorting）. First, aLagrange multiplier is introduced to simplify the mean-variance problem and thecorresponding Hamilton-Jacobi-Bellman （HJB） equation is established. Via a powertransformation technique and variable change method, the optimal strategies withthe Lagrange multiplier are obtained. Final, based on the Lagrange duality theorem,the optimal strategies and optimal value for the original problem （i.e., the efficientstrategies and efficient frontier） are derived explicitly.
基金National Natural Science Foundation ofChina( 10 1710 66) and Shanghai Key Project( 0 2 DJ14 0 63 )
文摘This paper considered the problem of hedging a European call (put) option for a diffusion model where the asset price is influenced by n uncertain factors. The market is thus incomplete implying that perfect hedging is not possible. To derive a hedging strategy, it follows the approach based on the idea of hedging under a mean-variance criterion suggested by Schweizer. A very simple solution of this hedging problem by using the numeraire method was presented and some examples with explicit solutions were given.
文摘Since confidence is fading and anxiety is increasing in the US,America’s China policy has become more radical. In the short term, the US has the upper hand and China is in a relatively passive position. In the medium-and long-term, there will be more balance between them. This current strategic gambling between China and the US will be the major issue of international politics in the first half of the 21 st century and the most prominent external challenge China faces. China needs to make strategic adjustments but the gamble may be worthwhile in correcting imbalance in the international order and in the co-evolution of the two countries.
基金This work was supported by National Natural Science Fund of China (70102007/G0202)
文摘With the entry to WTO and development of IT, banks in China are adjusting their competitive strategies to meet the competition. Internet banking has become a kind of strategic choice to response to the entry to WTO. Based on relevantly selective reviews of literature of strategy theory and research, a model is developed to study banks' strategic response to entry to WTO. According to a survey of 192 sets of questionnaires, this study finds that external pressure, business strategy and perceived benefits of Internet banking would influence banks' perceived increase in Internet banking investment. And banks' perceived increase in Internet banking investment has no difference between big banks and small banks.
文摘Building a technology alliance is the main strategy for the United States to maintain its scientific and technological hegemony under its technopolitical strategic framework.After Joe Biden took office,the United States implemented“small yard with high fences”strategy for scientific and technological competition,as the first step toward building a technology alliance.The main goal is to restrict the flow of strategic emerging technologies and factors of innovation to rival countries.
文摘Aiming to reveal the university students＇ understanding in management as for the strategy and strategic management phenomena, this study accomplishes a phenomenographic research to assess the future managers＇ market perception. It was chosen university students in Management of a Portuguese University. We conclude that the strategy definitions obtained are an assembly of the diverse existing concepts. Concerning to strategic management it was perceived an approach with one of the main existing concepts. The findings raise interesting issues with respect to the difficulties felt by new managers in translating their theoretical definitions in real examples in the organizations.
文摘The key argument of this conceptual paper is that the roots of a viable future for an organisation are found in a robust strategic architecture perspective.The theoretical baselines for the concepts associated with this paper are linked to a variety of strategy theories.These include,but are not restricted to,institutional theory,strategic thinking relating to the positioning-based view(PBV)and resource-based view(RBV)respectively,entrepreneurial thinking,and innovation thinking.Strategy can be described as the collective,emerging pattern—based on strategic choices—an organisation consciously exhibits and executes over time to ensure its sustainable endurance by differentiating itself in unique ways to create and add value for stakeholders.Strategy is about explaining how an organisation wants to move forward and how it wants to advance the interests of stakeholders.A strategic landscape is the broad external and internal context of an organisation.An important part of strategy and the strategic landscape it operates in is how organisations define or“construct”their own“topography”or strategic architecture.A strategic architecture presents an organisation?s core logic for creating sustainable value,and therefore,forms the foundation of an organisation?s competitive potential in a specific context.This paper presents descriptions of the seven key buildings blocks that constitute a strategic architecture perspective for an organisation with an indication of strategy tools and frameworks that can be used to illuminate strategic possibilities,choices,and challenges to assist ongoing strategising praxis.The key features and assumptions associated with a strategic architecture perspective are discussed.A strategic architecture perspective assists leaders to work through the strategic complexity to arrive at simplicity in the form of clarity on external and internal strategic leverages,strategic aspirations,core strategic choices,plausible multiple scenarios,focused strategic goals,and success measurements to guide strategy execution and ongoing strategy renewal and innovations for proactive strategic decision-making through various dialogues with key stakeholders.
基金supported by a Horizontal Project on the Development of a Hybrid Energy Storage Simulation Model for Wind Power Based on an RT-LAB Simulation System(PH2023000190)the Inner Mongolia Natural Science Foundation Project and the Optimization of Exergy Efficiency of a Hybrid Energy Storage System with Crossover Control for Wind Power(2023JQ04).
文摘Present of wind power is sporadically and cannot be utilized as the only fundamental load of energy sources.This paper proposes a wind-solar hybrid energy storage system(HESS)to ensure a stable supply grid for a longer period.A multi-objective genetic algorithm(MOGA)and state of charge(SOC)region division for the batteries are introduced to solve the objective function and configuration of the system capacity,respectively.MATLAB/Simulink was used for simulation test.The optimization results show that for a 0.5 MW wind power and 0.5 MW photovoltaic system,with a combination of a 300 Ah lithium battery,a 200 Ah lead-acid battery,and a water storage tank,the proposed strategy reduces the system construction cost by approximately 18,000 yuan.Additionally,the cycle count of the electrochemical energy storage systemincreases from4515 to 4660,while the depth of discharge decreases from 55.37%to 53.65%,achieving shallow charging and discharging,thereby extending battery life and reducing grid voltage fluctuations significantly.The proposed strategy is a guide for stabilizing the grid connection of wind and solar power generation,capability allocation,and energy management of energy conservation systems.
