The developmental process of flood shoals based on observations in Toufutsu lake, Japan

Recently, the flood tidal sand bars have been developed at the entrance channel of Toufutsu Lake located along Okhotsk Sea in Hokkaido, and they affect flood control, inland water fisheries in lake, and so forth. In this study, we aimed to reveal the developmental process of sand bars by observations, which are velocity observation, water level observation, bed material investigation and video monitoring. Followings were major accomplishments of this study. (1) The maximum magnitude of reverse velocity at St.400 in the entrance channel during the periods of flood-tide was faster than that of normal velocity during the periods of ebb-tide. (2) The relationship between velocity at SP400 and friction velocity at SP400 during the periods of flood-tide is different from that during the periods of ebb-tide. (3) The\ud flood tidal sand bars at the entrance channel of Toufutsu Lake were developed by not only sea waves, but also adverse tidal current in the spring-tide

Groundwater management based on monitoring of land subsidence and groundwater levels in the Kanto Groundwater Basin, Central Japan

Over 40 million people live on and exploit the groundwater resources of the Kanto Plain. The Plain encompasses metropolitan Tokyo and much of Chiba Prefecture. Useable groundwater extends to the base of the Kanto Plain, some 2500 to 3000 m below sea level. Much of the Kanto Plain surface is at sea level. By the early 1970s, with increasing urbanization and industrial expansion, local overdraft of groundwater resources caused major ground subsidence and damage to commercial and residential structures as well as to local and regional infrastructure. Parts of the lowlands around Tokyo subsided to 4.0 m below sea level; particularly affected were the suburbs of Funabashi and Gyotoku in western Chiba. In the southern Kanto Plain, regulations, mainly by local government and later by regional agencies, led to installation of about 500 monitoring wells and almost 5000 bench marks by the 1990's. Many of them are still working with new monitoring system. Long-term monitoring is important. The monitoring systems are costly, but the resulting data provide continuous measurement of the "health" of the Kanto Groundwater Basin, and thus permit sustainable use of the groundwater resource

Performance Analysis of 6 Slot 8 Pole Permanent Magnet Linear Motor

Currently, palm oil is the mostconsumedvegetable oilin the world. Therefore, an increment in its productivity is essential to ensure its sustainability in the market. One option is through the mechanization of the tools used to harvest it. In this paper, the design of the actuator for mechanized oil palm harvesting tools was discussed. A 3 phase permanent magnet linear motor with a 6 slot 8 pole structure topology known as 3PhSTLOA was used as the actuator structure. The structure of 3PhSTLOA has been optimized. The aim of the optimization is to allow the 3PhSTLOA to produce at least 200 N of average thrust at a total weight of under 2.0 kg. As a result of optimizing the 3PhSTLOA produced about 202 N of average thrust at 1.8 kg of its total weight. The performance of 3PhSTLOA is then compared with the previous type of actuator in mechanized harvesting tools

Boolean Dynamics with Random Couplings

This paper reviews a class of generic dissipative dynamical systems called N-K models. In these models, the dynamics of N elements, defined as Boolean variables, develop step by step, clocked by a discrete time variable. Each of the N Boolean elements at a given time is given a value which depends upon K elements in the previous time step. We review the work of many authors on the behavior of the models, looking particularly at the structure and lengths of their cycles, the sizes of their basins of attraction, and the flow of information through the systems. In the limit of infinite N, there is a phase transition between a chaotic and an ordered phase, with a critical phase in between. We argue that the behavior of this system depends significantly on the topology of the network connections. If the elements are placed upon a lattice with dimension d, the system shows correlations related to the standard percolation or directed percolation phase transition on such a lattice. On the other hand, a very different behavior is seen in the Kauffman net in which all spins are equally likely to be coupled to a given spin. In this situation, coupling loops are mostly suppressed, and the behavior of the system is much more like that of a mean field theory. We also describe possible applications of the models to, for example, genetic networks, cell differentiation, evolution, democracy in social systems and neural networks.Comment: 69 pages, 16 figures, Submitted to Springer Applied Mathematical Sciences Serie

Constitution of an Approximate Equation of Demagnetizing Factors for Cylinder Using Multiple Regression Analysis

An approximate equation is constituted for a cylinder as a function of the aspect ratio of its length to diameter and its normalized axial position. In order to create reference points for the approximate equation, the demagnetizing factor distribution of the cylinder, which has several ratios in a uniform applied field, is computed using a finite element method. From the results of the computations, an approximate equation at an arbitrary Z value along the axial direction of the cylinder is constituted from a multiple regression analysis.ArticleJournal of the Japan Society of Applied Electromagnetics and Mechanics. 17(3):449-452 (2009)journal articl

Characteristics of bottom surface sediments in relation to wind and wave action in Lake Kitaura, central Japan

ArticleThe Journal of the Geological Society of Japan. 110(1): 1-10 (2004)journal articl