Statistical Mechanics of Time Domain Ensemble Learning

Conventional ensemble learning combines students in the space domain. On the other hand, in this paper we combine students in the time domain and call it time domain ensemble learning. In this paper, we analyze the generalization performance of time domain ensemble learning in the framework of online learning using a statistical mechanical method. We treat a model in which both the teacher and the student are linear perceptrons with noises. Time domain ensemble learning is twice as effective as conventional space domain ensemble learning.Comment: 10 pages, 10 figure

Adhesion, friction and micromechanical properties of ceramics

The adhesion, friction, and micromechanical properties of ceramics, both in monolithic and coating form, are reviewed. Ceramics are examined in contact with themselves, other harder materials, and metals. For the simplicity of discussion, the tribological properties of concern in the processes are separated into two parts. The first part discusses the pull-off force (adhesion) and the shear force required to break the interfacial junctions between contacting surfaces. The role of chemical bonding in adhesion and friction, and the effects of surface contaminant films and temperature on tribological response with respect to adhesion and friction are discussed. The second part deals with abrasion of ceramics. Elastic, plastic, and fracture behavior of ceramics in solid state contact is discussed. The scratch technique of determining the critical load needed to fracture interfacial adhesive bonds of ceramic deposited on substrates is also addressed

Fundamental tribological properties of ion-beam-deposited boron nitride films

The adhesion, friction, and micromechanical properties of ion-beam-deposited boron nitride (BN) films are reviewed. The BN films are examined in contact with BN metals and other harder materials. For simplicity of discussion, the tribological properties of concern in the processes are separated into two parts. First, the pull-off force (adhesion) and the shear force required to break the interfacial junctions between contacting surfaces are discussed. The effects of surface films, hardness of metals, and temperature on tribological response with respect to adhesion and friction are considered. The second part deals with the abrasion of the BN films. Elastic, plastic, and fracture behavior of the BN films in solid-state contact are discussed. The scratch technique of determining the critical load needed to fracture interfacial adhesive bonds of BN films deposited on substrates is also addressed

Effect of abrasive grit size on wear of manganese-zinc ferrite under three-body abrasion

Wear experiments were conducted using replication electron microscopy and reflection electron diffraction to study abrasion and deformed layers produced in single-crystal Mn-Zn ferrites under three-body abrasion. The abrasion mechanism of Mn-Zn ferrite changes drastically with the size of abrasive grits. With 15-micron (1000-mesh) SiC grits, abrasion of Mn-Zn ferrite is due principally to brittle fracture; while with 4- and 2-micron (4000- and 6000-mesh) SiC grits, abrasion is due to plastic deformation and fracture. Both microcracking and plastic flow produce polycrystalline states on the wear surfaces of single-crystal Mn-Zn ferrites. Coefficient of wear, total thickness of the deformed layers, and surface roughness of the wear surfaces increase markedly with an increase in abrasive grit size. The total thicknesses of the deformed layers are 3 microns for the ferrite abraded by 15-micron SiC, 0.9 microns for the ferrite abraded by 4-micron SiC, and 0.8 microns for the ferrite abraded by 1-micron SiC

Policy problems relating to the labor immigration control in Japan

This paper provides analyses of the following issues: i) The desirable Japanese admittance system of foreign workers, ii) The effects on the Japanese population structure and economy to which immigrants may have. The analyses insist that Japan should introduce the point system to examine the admittance of foreign workers, and grant permanent residence to them at the time of new entry, but the benefit from admitting immigrants would be small and diminish according to aging of the immigrants group.

Externalities and Taxation/Subsidization Policy of Vehicle Information and Communication System

Traffic congestion in urban areas has become serious both in Japan and European countries.This study aims to calculate the optimal penetration level and taxation/subsidization level of VICS. VICS(Vehicle Information and Communication System) is a digital data communication system which promptly provides the latest necessary road traffic information to drivers via car navigation equipment. Drivers can receive real-time road traffic information about congestion and regulation 24 hours a day, 7 days a week. The world's first VICS service started in Japan in April 1996. It is impossible to realize the optimal level of penetration in the market mechanism when a service has technological externalities. VICS must have two type of technological externality. One is positive one-way externality which implies that the higher the level of penetration of VICS, the lower the travel times to the non-equipped drivers because of congestion reducing. The other is negative network externality which implies that a marginal equipped driver adversely affects the already equipped driver by increasing the travel time on alternative routes. Hence taxation or subsidization must be necessary to realize the optimal penetration level of VICS. Many studies explored the effect of market penetrations of PRG(route planning and guidance) on overall system travel time(e.g. Emmerink et al.(1995)). These studies, however, considered market penetration as an exogenous parameter. Recently, Yang (1999) developed the model to calculate the market penetration level endogenously. Lo and Szeto (2002) provided the methodology to analyze penetration level which simultaneously satisfies the three objectives (service providersÂf objective, traffic management agency's objective and usersÂf objective). But there are no studies to explore the optimal penetration level at which the marginal social benefit is equal to marginal social cost. This study develops the partial equilibrium economic model to calculate the optimal penetration level and taxation/subsidization level of VICS and calculate them by applying this model to Kantou-Area where is the most congested area in Japan. The result of our analysis shows that it must be necessary to realize optimal level of penetration of VICS to impose a fixed charge per VICS unit except in the case where the effect of negative externality is very weak.

Storage Capacity Diverges with Synaptic Efficiency in an Associative Memory Model with Synaptic Delay and Pruning

It is known that storage capacity per synapse increases by synaptic pruning in the case of a correlation-type associative memory model. However, the storage capacity of the entire network then decreases. To overcome this difficulty, we propose decreasing the connecting rate while keeping the total number of synapses constant by introducing delayed synapses. In this paper, a discrete synchronous-type model with both delayed synapses and their prunings is discussed as a concrete example of the proposal. First, we explain the Yanai-Kim theory by employing the statistical neurodynamics. This theory involves macrodynamical equations for the dynamics of a network with serial delay elements. Next, considering the translational symmetry of the explained equations, we re-derive macroscopic steady state equations of the model by using the discrete Fourier transformation. The storage capacities are analyzed quantitatively. Furthermore, two types of synaptic prunings are treated analytically: random pruning and systematic pruning. As a result, it becomes clear that in both prunings, the storage capacity increases as the length of delay increases and the connecting rate of the synapses decreases when the total number of synapses is constant. Moreover, an interesting fact becomes clear: the storage capacity asymptotically approaches $2/\pi$ due to random pruning. In contrast, the storage capacity diverges in proportion to the logarithm of the length of delay by systematic pruning and the proportion constant is $4/\pi$. These results theoretically support the significance of pruning following an overgrowth of synapses in the brain and strongly suggest that the brain prefers to store dynamic attractors such as sequences and limit cycles rather than equilibrium states.Comment: 27 pages, 14 figure