Research Reports :
Kushiro National College of Technology
No.32(1998) Abstracts

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Microstructure and Mechanical Properties of Stir-Cast Al-Mg Alloy

Abstract- The effect of stirring on the solidification process, the structure and the mechanical properties of Al-15%Mg alloy was investigated. Stirring speed was varied from 0 to 1500 r.p.m. in its solidification range. The fraction of secondary particles, which were formed by the fragment of the primary dendrite due to stirring, were increased with the increase of stirring speed. Homogeneous hardness distribution was obtained in stir-cast alloys comparing no-stirred alloy with its change at the top- bottom direction. Tensile fracture strength was increased and its fluctuation fell within small range with the increase of stirring speed.
Keywords : stir-casting, rheocasting, solidification, secondary solid particle, dendrite,

Making and EValuation for Experimenta| Apparatus of Friction Loss in Pipe Flow

Abstract- Experimental apparatus to measure friction loss in pipe flow was designed and made. It makes use of mechanical engineering experiment curriculum for students, and was devised deepen student's understanding of fluid phenomenon relate pipe flow. It's able to measure friction loss in straight pipe and pressure loss of a few piping items(bend, valve etc.), and observe flow state by visualization. Result of the evaluation were : 1. Friction factorλwere good agreement with theory and Brasiu's equation range Re=300~19000. 2.Loss coefficient of the piping items were a little different with general value on handbook. 3.Characterristic flow pattern of laminar, transition and turbulent were observed respectably by flow visualization.
Key Words : Friction factor, Pipe Flow, Flow Visualization

A Development of Material for CAD Education by using lnternet Browser

Abstract- In the many industries, the CAD (Computer Aided Design) system is being used for the design works that are effective at the new product development and the labor saving. So, the CAD training is being carried out in many industry educational institutions. However, the training method which used in these institutions was never effective and easy method.
This paper proposes a new training method for the CAD education. The proposing method uses WWW Browser for the CAD Training of operations and commands that is learning usually by the textbook. The students can learn the CAD operation easily by seeing Browser and the CAD window alternately. When it was actually used for the CAD exercise of our college, it showed a good result that the student's understanding was early.
In this paper, it examines the elements which is necessary for the CAD training, and explains about the constructions of Browser to learn the CAD operation.

Analysis of Electromagnetic Fields in an Anisotropic Medium by a FDTD Method

Abstract- In this paper, a FDTD method(finit-difference time-domain method) for solving two- dimensional electromagnetic field problems in a waveguide filled with an anisotropic medium is described. The method is applied to the electromagnetic field problem of a ferrite loaded rectangular waveguide. The electromagnetic field generatd by a magnetic current source in a parallel-plate plasma waveguide is also obtained by using the FDTD method. The numerical electromagnetic fields are compared with other theoretical values. We can conclude that the FDTD method is usefull for the analysis of electromagnetic fields in a waveguide filled with an allisotropic mediium.
Key words : anisotropic medium,waveguide,FDTD method

Study on DC Servo Motor Position Control (2)

Abstract- In this paper, simulation studis are carried out for brushless type DC moter positioning system with application of digital optimal preview control method.
Considerable reduction in peformance index value, lowering of input peak value and improvement of the tracking performance to reference under the disturbance are obtained by applying the digital optima1 preview control method.
Key words : Brushless type linear DC moter, Position control, Digital optima1 preview control

New Educational Computer System in Kushiro Nationa| College of Technology

Abstract- In March,1998, Educational Computer System was renewed in our college. The system consists of 50 personal computers, 2 workstations and 3 page printers, is connected with LAN in the campus. Using the operating system, we can use Windows NT and UNIX. We will report the use of the system and the problem of it.
Key words : Educationa1 Computer, personal computers, LAN, Windows NT, UNIX

Education for lnformation Processing with lntelligentPad System

Abstract- This paper describes a new learning environment to aid the information processing edcation. The learning method proposed here is using lntelligentPad system. The programs of objective are programmed by composing the basic parts which has the function prepared for in advance and the parts which can be defined newly (i.e.Pad). By using this system, the students can study to learn the program architecture purely. Some practices and lessons are carried out and the students show the good understanding to the programming at these results.

The lnfluence of a Process to Make a Thermoelectromotive Force of FeSi2 Heat Electricity Conversion Element

Abstract- By paying attention to the concentration of impurities at the measuring process to make FeSi2 Heat Electricity Conversion Element, it has been researched how much influence the concentration of impurities have on a Thermoelectromotive Force and also how long the most suitable heat treatment time is.
This paper is the report confirming that the Thermoelectromotive Force increases when the concentration of impurities is higher than the standard and the heat treatment time is longer.
Key words : Thermoelectromotive Force, FeSi2

Automatic lndexing Service on the World Wide Web

Abstract- We started an automatic indexing service for scientific documents on the World Wide Web. This system fetches a specified text file over the Internet and automatically adds HTML markup tags for indexing. Users can easily access to the system with WWW browsers and simply input the URL specifying the target file. Soon the indexed file appears on WWW browsers and users can browse and save the file.
Key words : automatic indexing, hypertext markup language, world wide web, technical term, scientific document

An Optimal Parallel Algorithm for Constructing a Spanning Forest on lnterval Graphs

Abstract- Let G =(V,E) be a simple graph with n vertices, m edges and p connectedcomponents. The problem of constructing a spanning forest is to find a spanning tree foreach connected component of G. For a simple graph, Chin et al.[4] demonstrated that a spanning forest can be found in O (log 2 n) time using O (n 2/log 2 n) processors. In this paper, we propose an O (log n) time optimal parallel algorithm withO (n /log n) processors on the EREW PRAM for constructing a spanning tree on Interval graphs.
Key words : Parallel algorithms, Interval graphs, Spanning tree

The Study of the Two-layer RBF Network for Recognition Visual Patterns

Abstract- This report presents the result of applying the two-layer RBF network to visual pattern recognition.This experiment is intended to build visual pattern recognition system which can distinguish eye,nose and mouth,We developed the network using 18 types of graphic data and the system recognized them, Study results indicated that the network which has 3‐node at output-layer and 8 or more nods at input-layer can ensure 100% recognition rate.

Resistance of Specia| Light Weight Mortar against Freezing and Thawing

Abstract- The following results were obtained by our experiment.
(1) Established mortar was not affected by the too cruel examination condition of freezing and underwater thawing, and with no deterioration the mortar showed high numerical value of adhesion strength up to 100 cycles. But a sudden fall of distortion due to axis distortion flattery was observed to some extent. Paying attention is needed with respect to durability.
(2) We got no good result with the strength of special mortar, but flattery for distortion and tenacity were confirmed by the experiment of axis distortion flattery. Its effectiveness was recognized with respect to the protection against tile exfoliation.

Mesurement of Natural Room Temperature of the Solar System Model with Thermal Storage Floor (2)

Abstract- We have done some experiments by using small passive solar system models with thermal storage floor for last several years. This time experiment was done by measuring globe temperature and floor surface temperature in 2 cubic house models. By results of experiment, we found proper azimuth of window surface and effect of insulating door for night thermal condition in the model house.

A Study on Village Park Planning with Workshop Style by Residents' Participation

Abstract- The present writer was concerned in Village Park Planning with workshop at Nishiensyubetu in Hamanaka. A purpose of this Study is to evaluate workshop by residents' participation and to search for a problem to be solved.
A method of this Study is to send out questionnaires to a participant of workshop and to analyze them.

On Effective Ways to Have Students Memorize the Meanings of English Words

Abstract- We memorize the meanings of English words in many ways, such as spelling them, associating them with something, pronouncing them and so on. This paper sets out to examine what way is the most effective in learning words by heart for a period of seven days.
Key words : short-term memory, memory strategy, recognition