English summary of the 3 number of volume 43 publishing paper

Original Paper

Title: The Development of a Stirling Engine as a Teaching Material for Making-Things
Author: Hiroshi OKURA, Naobumi SUMI

題目：ものづくり教材としてのスターリングエンジンの開発
著者：大倉宏之・須見尚文

Abstract

The Stirling Engine, which was invented by Robert Stirling in 1816, is an external combustion engine. The structure and mechanism are very simple because it does not need any other assistant mechanism to operate. The engine can also use many types of fuel including solar energy and hot spring heat source. Therefore, the engine is considered to have many advantages and possibilities as the teaching material for making-things of technological education at junior high school.
This paper is concerned with the development and application of the Stirling engine as the teaching material for making-things of technological education. The engine is invented so that the students can easily mike this engine. In designing the engine, it is initiated to use many kinds of materials including empty can from the aspects of processing learning and effective use of resources. Moreover, many kinds of work elements are included to learn the processing technique.
We also contrived many processing devices in order to shorten times necessary for students to mike parts of the engine.
The students can learn the mechanism, the concept of energy conversion, and the processing skill of materials by making this engine by themselves. Therefore, the engine developed in this study is considered to be an excellent teaching material for making-things of technological education.

Key words: teaching material for making-things, Stirling engine, energy conversion, skill study, environmental education

Title: A Structural Analysis of Students' Thinking at the Design stage in Manufacturing Class
Author: Chikahiko YATA, Koichi MURATA, Kunio UEDA

題目：｢ものづくり学習｣の設計段階における中学生の思考活動の構造把握
著者：谷田親彦・村田耕一・上田邦夫

Abstract

The purpose of this research is to analyze students' thinking at the design stage in manufacturing class in order to better lessons. A questionnaire, made up of 35 questions, was conducted on 777 students. The thinking structure at the design stage was made clear by using factor analysis and cluster analysis. The results are summarized as follows:
(1) Students' thinking at the design stage are composed of five factors named 'examination of material and processing methods' 'examination of use condition' 'consideration to the production and use stage' 'examination of processing degree of difficulty' and 'examination of the value added'
(2) Examination of material and processing methods' factor is composed of a combination of the examination of processing methods it from explicit and implicit condition of the material, and strength and durability of material. 'Examination of use condition' factor is organized into two clusters: the concrete function and the abstract function.
And, 'consideration to the production and use stage' is considered to be constituted of decision of product's attribute, try to devise and draw lines of the parts on the material efficiently.

Key words: manufacturing class, design stage, junior high school students, thinking, factor analysis, cluster analysis.

Title: A Study of the Formation of Students' Plans in the Process of Designing for Thing-Making
Author: Kimihito TAKENO

題目：ものづくりの構想段階における生徒の計画作成に関する基礎的研究
著者：岳野公人

Abstract

This paper examines the importance of plans for thing-making, and investigates how students make their own plans for production. To analyze the students' plans, I gave them a situation test at the process of design stage for thing-making. The following results were obtained from the analyses:
1) The differences in their planning are roughly classified into two groups: the itemization of the purposes of their production, and diagrams illustrating the changing appearance of their production.
2) The students' production plans consist of such items as designing, preparation, programs, control of the outcome, and self-motivation for production.

Key words: Thing-Making, Designing, planning, Factor of a Plan

Practical Paper

Title: Development of Report Reception System with Use of Web
Author: Minoru MATSUYAMA, Katsumi YAMAGUCHI, Hiroyuki YASUI

題目：Web機能を利用したレポート受付システムの開発
著者：松山　実・山口勝己・安井浩之

Abstract

In Informatics Education, it is important from the viewpoint of effective study for students to submit reports. However, this makes for a substantial workload for the instructor. The mind of studying may decline in case that students cannot submit reports due to the complicated operation. Furthermore, increasing is the necessity of reception of reports from a distant area because of the credit exchange between different faculties and different universities. To overcome these issues, a report reception system was developed in the present study exploiting the function of the Web. Throughout the two years operation of the system, it is confirmed that the system gives a minimal workload to both students and instructors, and works with a response time short enough even when the submission concentrates just before the deadline. The paper also presents the function of the system and discusses the associated problems and possible solutions.

Keywords: Report Reception System, web, Internet, CGI

Title: Experimental Evaluations of the Electrical Characteristics of Electricity-Made
Hotcake, or 'Denki-Pan' Experiment and its Safety as Food
Author: Mamoru MATSUOKA, Hitoshi IWASE, Yoshikazu TESHIMA,
Hitomi HAYAKAWA, Keizou WAKITA, Yasuaki OMOTO,
Hiroyuki KAWAGUCHI, Yuuichi HIRAYAMA, Kazutoshi MATSUMURA,
Kei MIYAMA, Motoichi KAWAGUCHI

題目：｢電気パン｣実験に対する電気的特性の実験的評価と食品としての安全性
著者：松岡　守・岩瀬仁志，手嶋由和・早川ひとみ・脇田圭造・尾本保明・川口博之・平山雄一・松村和俊・宮間　敬・川口元一

Abstract

The conditions for baking hotcakes well and their safety as food were experimentally tested for the so-called 'Denki-Pan' experiment, where hotcake paste was introduced into a milk pack and then baked by 100V AC applied through a pair of electrodes immersed in the paste. We found insulation layers were formed when a pair of aluminum electrodes was used and the hotcakes were not baked well. When a pair of stainless steel electrodes was used, such layers were not formed. We concluded that hotcakes can always be baked well if stainless steel electrodes are used with appropriate relation between electrode spacing and electric conductivity of hotcake paste. We also found that some unexpected materials were formed by electrochemical reactions and mixed in the baked hotcakes. Therefore, we concluded that the baked hotcakes should not be treated as a food, though 'Denki-Pan' experiment is an interesting material in elementary and middle education.

Key words: Denki-Pan, hotcake, safety as food, electrochemical reaction

Technical Information

Title: Using a One Chip Microcomputer to Control a Three Phase Bridge Rectifier with a Frequency Multiplier
Author: Haruyoshi AKIBA

題目：ディジタル周波数マルチプライヤを用いた三相ブリッジ整流回路のワンチップマイコン制御
著者：秋葉治克

Abstract

This paper describes a new digital control system adopted for a one chip microcomputer for a three phase bridge rectifier circuit. In this system, the author tried to make the circuit compact by combining both a PLL circuit and a phase control circuit, employing a one chip microcomputer and a programmable interval timer. The programmable interval timer is a timer chip containing three 16 bit counters which can operate in a number of different modes as determined by the program. Under this system, each counter is used in the following manner. The first counter generates a reference signal synchronized with the line. The second counter generates controlling pulse trains having a frequency six times as high as a conventional reference frequency locked into a reference signal by creating a new digital frequency multiplier. The third counter starts counting a precise phase control angle 1243 using the moment when the pulse trains are generated as a reference time. The characteristics of this one chip microcomputer such as low price, compactness and convenience, are fully demonstrated. Finally, a thyristor phase control system of highly precise digital type was possible to construct in this study.

Key words: PLL, frequency multiplier, three phase bridge rectifier circuit, phase control