A Simplified Approach to Analyzing Multi-regional Core-Periphery Models

This paper shows that the evolutionary process of spatial agglomeration in multi-regional core-periphery models can be explained analytically by a much simpler method than the continuous space approach of Krugman (1996). The proposed method overcomes the limitations of Turing's approach which has been applied to continuous space models. In particular, it allows us not only to examine whether or not agglomeration of mobile factors emerges from a uniform distribution, but also to trace the evolution of spatial agglomeration patterns (i.e., bifurcations from various polycentric patterns as well as from a uniform pattern) with decreases in transportation cost.agglomeration; core-periphery model; multi-regional; stability; bifurcation

Experimental and Theoretical Evaluation of the Effect of Panel Geometry on the Failure of Corrugated Board Panel

McKee’s formula is widely used to predict the compression strength (CS) of corrugated boxes and panels. It can accurately estimate the compression strength of boxes that are within a practical size range, but recently, larger and smaller corrugated boxes than before have been extensively developed. Therefore, there is a need for a CS prediction formula that works beyond the application range of McKee’s formula. Recent researches consider the failure mode as a combination of collapsing and buckling failure and remove the constraints and the assumptions associated with McKee’s formula. This makes it possible to more accurately estimate the CS of boxes that are not covered by McKee’s formula. Many CS formulae are derived logically from material mechanics, but doing so can make it difficult to account for various actual behaviors in detail up to when the box fails. Instead, by analyzing the behavior up to failure in detail, we explored relationships that could account for the CS consistently based on its behavior

Digital-twin-compatible Optimization of Switching Characteristics for SiC MOSFETs using Genetic Algorithm

Active gate drive (AGD) is one of the key techniques to utilize SiC power devices' fast-switching capability without compromising the drawbacks. However, the increasing complexity in the circuit design makes it hard to have an optimized operation without expert know-hows or considerable design efforts. This paper demonstrates a digital-twin-compatible metaheuristic optimization system for a digital AGD. It offers a totally-digital control of switching characteristics of power devices through genetic-algorithm-based optimization. An individually developed digital AGD is adopted to generate a genetically expressed gate-voltage waveform by a multi-bit gate signal sequence. The optimization system is verified in simulation and experiment by successfully obtaining the optimum Pareto-front solutions, which clarify the relationship between the selected gate voltage levels and the device characteristics. The optimization is also performed for variable operating conditions and for different SiC MOSFETs. The results of this paper offer feasibility for a software-based optimization of gate drive design

An application of differential game theory to a dynamic duopoly problem with maximum production constraints / BEBR No. 360

Includes bibliographical references (leaves 21-22)

Periostin Associates with Notch1 Precursor to Maintain Notch1 Expression under a Stress Condition in Mouse Cells

BackgroundMatricellular proteins, including periostin, modulate cell-matrix interactions and cell functions by acting outside of cells.Methods and FindingsIn this study, however, we reported that periostin physically associates with the Notch1 precursor at its EGF repeats in the inside of cells. Moreover, by using the periodontal ligament of molar from periostin-deficient adult mice (Pn−/− molar PDL), which is a constitutively mechanically stressed tissue, we found that periostin maintained the site-1 cleaved 120-kDa transmembrane domain of Notch1 (N1™) level without regulating Notch1 mRNA expression. N1™ maintenance in vitro was also observed under such a stress condition as heat and H2O2 treatment in periostin overexpressed cells. Furthermore, we found that the expression of a downstream effector of Notch signaling, Bcl-xL was decreased in the Pn−/− molar PDL, and in the molar movement, cell death was enhanced in the pressure side of Pn−/− molar PDL.ConclusionThese results suggest the possibility that periostin inhibits cell death through up-regulation of Bcl-xL expression by maintaining the Notch1 protein level under the stress condition, which is caused by its physical association with the Notch1 precursor

Origin of power laws and their spatial fractal structure for city-size distributions

City-size distributions follow an approximate power law in various countries despite high volatility in relative city sizes over time. Our empirical evidence for the United States indicates that the scaling law stems from a spatial fractal structure owing to the coordination of industrial locations. While the locations of individual industries change considerably over time, there is a persistent pattern in that the localized industries at a given time are found only in larger cities. The spatial organization of cities exhibits a stable hierarchical structure in which larger cities are spaced apart to serve as centers for surrounding smaller cities, generating a recursive pattern across different spatial scales. In our theoretical replication of the observed regularities, diversity in scale economy among industries induces diversity in their location pattern, which translates into diversity in city size via spatial coordination of industries and population. The city-size power law is a generic feature of Monte-Carlo samples of stationary states resulting from the spontaneous spatial fractal structure in the hypothetical economy. The identified regularities reveal constraints on feasible urban planning at each regional scale. The success or failure of place-based policies designed to take advantage of individual cities' characteristics should depend on their spatial relationships with other cities, subject to the nationwide spatial fractal structure

A Simplified Approach to Analyzing Multi-regional Core-Periphery Models

This paper shows that the evolutionary process of spatial agglomeration in multi-regional core-periphery models can be explained analytically by a much simpler method than the continuous space approach of Krugman (1996). The proposed method overcomes the limitations of Turing's approach which has been applied to continuous space models. In particular, it allows us not only to examine whether or not agglomeration of mobile factors emerges from a uniform distribution, but also to trace the evolution of spatial agglomeration patterns (i.e., bifurcations from various polycentric patterns as well as from a uniform pattern) with decreases in transportation cost

A Simplified Approach to Analyzing Multi-regional Core-Periphery Models

This paper shows that the evolutionary process of spatial agglomeration in multi-regional core-periphery models can be explained analytically by a much simpler method than the continuous space approach of Krugman (1996). The proposed method overcomes the limitations of Turing's approach which has been applied to continuous space models. In particular, it allows us not only to examine whether or not agglomeration of mobile factors emerges from a uniform distribution, but also to trace the evolution of spatial agglomeration patterns (i.e., bifurcations from various polycentric patterns as well as from a uniform pattern) with decreases in transportation cost

Hemodynamic Changes in the Brachial Artery Induced by Acupuncture Stimulation on the Lower Limbs: A Single-Blind Randomized Controlled Trial

Acupuncture is commonly performed at acupoints. No comparisons of quantitative physiological alterations in the brachial artery (BA) induced by the stimulation of different acupoints in the lower limbs have been performed in humans. Therefore, we investigated changes in blood flow volume (BFV) in the BA as an indicator of the physiological effects induced by stimulation at 3 points. Seventy-five healthy participants aged 33 ± 9 years (mean ± SD) were enrolled and randomly assigned to 3 groups; they received stimulation at 3 different points located on the lower limbs: ST36, LR3, and a non-acupoint. Stimulation was performed bilaterally with manual rotation of the needles. Using ultrasonography, BFV was measured continuously from rest to 180 seconds after stimulation. LR3 stimulation significantly increased BFV compared to that before needle insertion. Meanwhile, stimulation at ST36 and the non-acupoint significantly decreased BFV compared to that before needle insertion. Stimulation at LR3 elicited a significant increase in BFV compared to that at ST36 and the non-acupoint. The results suggest that the stimulation of different points on the lower limbs causes distinct physiological effects on BFV in the BA