Transversality Conditions for Higher Order Infinite Horizon Discrete Time Optimization Problems

In this paper, we examine higher order difference problems. Using the "squeezing" argument, we derive both Euler's condition and the transversality condition. In order to derive the two conditions, two needed assumptions are identified. A counterexample, in which the transversality condition is not satisfied without the two assumptions, is also presented

Heterogeneous impacts of COVID-19 on trade : evidence from China\u27s province-level data

This study investigates how the extent of COVID-19 damage affected China’s province-level trade with foreign countries and reports the heterogeneous effects of these damages. Using monthly trade data for January–August 2019 and 2020 and the number of confirmed COVID-19 cases, in a gravity equation, we measure the damage extent on exports and imports separately. The results show that a provincial rise in the confirmed cases decreases exports and imports, especially until March. The larger negative effects of COVID-19 are more prominent on the processing than ordinary trade; these effects are smaller in provinces with a larger number of deaths during the severe acute respiratory syndrome outbreak. However, urbanization and mobile phone diffusion exhibit a potential to mitigate these effects on trade

Hydrogen assisted growth of high quality epitaxial graphene on the C-face of 4H-SiC

We demonstrate hydrogen assisted growth of high quality epitaxial graphene on the C-face of 4H-SiC. Compared with the conventional thermal decomposition technique, the size of the growth domain by this method is substantially increased and the thickness variation is reduced. Based on the morphology of epitaxial graphene, the role of hydrogen is revealed. It is found that hydrogen acts as a carbon etchant. It suppresses the defect formation and nucleation of graphene. It also improves the kinetics of carbon atoms via hydrocarbon species. These effects lead to increase of the domain size and the structure quality. The consequent capping effect results in smooth surface morphology and suppression of multilayer growth. Our method provides a viable route to fine tune the growth kinetics of epitaxial graphene on SiC.Comment: 9 pages, 4 figure

ネガティブショックが企業行動に与える影響に関する理論的分析

2020南山大学ネガティブショックが企業行動に与える影響に関する理論的分析2017～2020年度科学研究費助成事業 (基盤研究 (C) (一般)) 研究成果報告

Constructing the Optimal Solutions to the Undiscounted Continuous-Time Infinite Horizon Optimization Problems

We aim to construct the optimal solutions to the undiscounted continuous-time infinite horizon optimization problems, the objective functionals of which may be unbounded. We identify the condition under which the limit of the solutions to the finite horizon problems is optimal for the infinite horizon problems under the overtaking criterion