工学部紀要理工編 抄録（Vol.23 No.1）

Much attention has been paid to synthesis of inorganic compounds by a material processing utilizing various kinds of concerted amplification. The author review mechanochemical process as one of the physical methods which activate the chemical reaction. Carbides, silicides, nitrides and borides were recently synthesized by ball-milling of the elemental powder mixtures without external heat application. The mechanochemical syntheses of these compounds can be divided into ； (1) direct formation of the compounds by instantaneous reaction in case of TiC, TiB2, MoSi2, ZrSi2, Ti5Si3, etc.；or, (2) formation of fine powder mixture by which diffusion process is promoted, followed by annealing at relatively low temperature in case of CrB2, CrSi2, WSi2, SiC, etc. The exothermic nature of the reaction system determines the reaction route for the formation of a compound. Mechanochemical synthesis of nitrides were also reported for TiN, BN, Si3N4, β-C3N4, etc. Furthermore, the mechanochemical synthesis of the high melting compounds such as WC, TiB2 and TiC by the reducion of oxides have been examined.

The purpose of our study is to improve our architectural design education using digital tools and computer network by recording educational process on web pages and sharing it among students.
In this paper, we report last year's attempt to improve Architectural DesignV of third year later term which we took charge of, using computer network and multimedia equipment that was installed in every booth of the drawing room.
First, in addition to the conventional drawing course, we set up another course of which final presentations were made on web pages. Both courses have the same subject conditions and they are made to coexist. Secondly, in the programming process, the record of every week's presentations and the summary of all member's workshop about planning subject, such as the way of thinking and ideas were presented in the homepage, and they were shared by students. Finally, inter-school design review of the final presentation using drawings and models was held with video conferencing system. And now by way of the bulletin board with images we intend to record the design process also of the conventional drawing course and exchange opinions through www, aiming at network design collaboration this coming term.

The development and the diffusion of the personal computer have opened new possibilities in the field of education. The computer simulations enable the student to understand the essence of the phenomenon visually and intuitively. Video clips that represent the demonstration experiments will attract the interest of the student for the natural phenomenon. Multimedia and Internet will also give a great contribution to the field of education.
We have produced a hypertext of physics for freshmen. The text is written in Html (Hyper Text Markup Language) and can be seen by using an internet browser Netscape, Internet Explore and so on. The hypertext consists of not only a text including figures and photos but also simulations and video clips. The simulation programs are described with Java and they also can be operated on the internet browsers.

In this note, the dynamics of real biquadratic polynomials is investigated. Especially, in the parameter space, landing and non-landing of stretching rays on the parabolic arc is studied. It turns out that the stretching ray with Böttcher vector 1/2 lands at (1/4,1/4).

A binary computer generated hologram (CGH) and a Fourier transform hologram (FTH) with gray level/quasi-colors are similar to all appearance in the structure of hologram cell. However, they are wholly distinct each other in display techniques. We directly take a picture of reduced size of FTH displayed on a standard color LCD/CRT using a special negative film with high contrast in this study. A few examples of optical diffractive images are demonstrated for the comparison of the proposed FTH techniques with the classic binary CGH techniques from the viewpoint of visual appearance and image quality.

In this article we shall investigate the H-T conjectures for algebraic cycles on projective smooth varieties and give an observation, proofs and its application to some conjectures for the motivic theory.

The purposes of this paper are to point out the problems of the Basic Education of Information Technology for Faculty of Engineering and to develop a new concept useful in future. A new subject on Information literacy will begin in 2002 for primary and secondary education, and then "Information Study" for high schools in 2003. As a result the Information Study for University will necessarily have to be changed. In this paper, the basic Education of Information Technology in Faculty of Engineering based on their trends is proposed, and at the next step of this course it will be important to teach the techniques of computer programming and the fundamental theory of system engineering.

This paper proposes a suitable switching pulse pattern generating algorithm for a high-frequency link soft-switching converter which has been previously proposed by the authors. The target converter is characterized by its totally soft-switched operation, isolated output stage and bidirectional power flow. Therefor it is suited for interfacing a new energy system such as a PV system having a battery with ac system line. In applying the instantaneous space vector modulation scheme to generate the switching patterns for its three-phase output stage, the transition between output voltage vectors is restricted in order to realize soft switching operation. This paper firstly discuses on the restriction, and then, proposes a suitable switching pattern which satisfies the soft switching operations. To confirm the validity, a simplified simulation study has been carried out by using general purpose circuit simulator PSIM.

In order to estimate the legibility of elderly people, we tested reading speed of characters on a CRT display. The subjects put on the special glasses simulating the age-related transmittance reduction of the eye lens. There found no significant influence on reading speed whether the subjects put on the glasses or not. However, subjective rating of legibility was significantly lower with the glasses in the case of dark color characters on a blue background. These results indicate that dark color characters on a blue background should be avoided for elderly computer users.

Mamakodate is a Japanese traditional game. It was already known in early Kamakura period. The rule is similar to that of the problem of Josephus in the Western sphere, but there are some characteristic properties not common in the western culture. Because of the difference of the rules, Mamakodate has some superficially probabilistic feature compared to Josephus' problem, which is a simple deterministic game. This paper examines these features of Mamakodate in the light of cultural history of mathematics.

Teaching materials for chemistry education have been compared between Japan and United States with a special reference to the application of multi-media. At the same time, circumstances of chemical education have been compared between the two countries. United States has an overwhelming power in the scientific research, and it must be based on the excellent education. The key factors,　which differentiate the two countries, are discussed.

Admission decisions are based on applicants' high school records, their entrance examination scores, interview to them, and others. For future admission decisions, the relationship between the evaluation of applicants and their grades in undergraduate course should be investigated. We collected various data of all the students who entered the university from 1991 to 1995. The main results are:
1. The students' high school records and their grades in undergraduate course correlate to some extent.
2. There is no correlation between students' high school ranks with their grades in undergraduate course. But it is effective to add their high school ranks to correlation models of their grades in undergraduate course by their high school records.
3. Students' scores of entrance examinations and their grades in undergraduate course are correlated. This correlation is confirmed when we combine them with the students' high school records and their high school rank.