Hiroshima Institute of Technology Academic Repository
Not a member yet
1155 research outputs found
Sort by
A study on slip-load subjected to cyclic loading of large displacement
Full text linkapplication/pdfThe authors propose a rotational mechanism, referred to as a Beam-Joint-Plastic-Hinge, utilizing the sliding behavior of a high-strength bolt friction joint shown in Figure 1, aiming to improve
the accuracy of plastic hinge evaluation. Beam- Joint-Plastic-Hinge results in repeated large sliding displacements during repetitive joint plastic rotations.
As shown in Figure 2, the contact between solid bodies, including the base material and the splice plate, is established by the contact of tiny surface asperities（hereafter referred to as "true contact"）. In high-strength bolt friction joints, contact pressure acts on the true contact area, and
relative displacement between the base material and splice plate occurs as surface asperities are destroyed（sliding behavior）. In cases of repeated large displacements, achieving a stable sliding load
with small variations（refer to Figure 2）could simplify the bending strength of Beam-Joint-Plastic- Hinge, leading to an expected improvement in evaluation accuracy.
Therefore, to track the conditions for achieving a stable sliding load, sliding element experiments were conducted using frictionally joined steel plates. In this paper, we summarize these results and present insights gained regarding sliding loads under repeated large displacements.departmental bulletin pape
Research of visualization of complex eigenvectors in the phase plane of vehicle (a linear bicycle model) dynamics
Full text linkapplication/pdfIn a linear bicycle model, for the Under Steer（US）vehicle, the eigenvalues and eigenvectors of the A matrix in the state equation are conjugate complex numbers. Therefore, they cannot be visualized by drawing them on a two-dimensional plane, as is the case with real eigenvalues and real eigenvectors. Similar studies of such visualization have been conducted in automotive and control engineering, where state trajectories are drawn in the phase state plane, but there appears to be no research on the visualization of complex eigenvectors. Eigenvectors, whether real or complex, are added to the phase state plane to visualize the relationship between the state and the eigenvector. The visualization of states and eigenvectors allows to determine the degree of convergence or divergence of states. Furthermore, if there are multiple eigenvectors, it is possible to know which eigenvector to converge
to and to understand the state flow.
We report the results of our research on a method to reveal the relationship between states, eigenvalues and eigenvectors by quasi-visualizing the complex eigenvectors of the Under Steer vehicle.departmental bulletin pape
A study on development and implementation of teaching materials for structural mechanics considering career development and survey of their attitudes
Full text linkapplication/pdf本論では、一級建築士試験を視野に入れた構造力学の計算問題に関する教材開発、および授業での実践について論じる。受講生を対象に建築士資格に関するアンケート調査を実施し、受験に対する意識・認識等を分
析・考察する。さらに、開発した教材を用いて講義した後に再度アンケート調査を実施し、意識・認識等の変化を分析・考察する。受講前アンケート調査の結果、回答者の90％は一級建築士の取得を目指しているが、回答者の93％は現状の実力では合格点に達しないと認識していることが分かった。開発した教材を用いて講義し、アンケート評価のフィードバックを行い、受講後アンケート調査を行ったところ、一級建築士から二級建築士試験にキャリアプランを変更した者がいることが分かった。その一方で、現状の実力で解けそうな構造力学の問題数は増えており、確実にボトムアップされたことが数値的に明らかになった。departmental bulletin pape
A study on the teaching of Ohm’s law in lower secondary school － IV graph or VI graph ？－
Full text linkapplication/pdfオームの法則の指導に苦労した教育実習生の疑問，「なぜ教科書はIV グラフなのだろうか」「VI グラフの指導ではいけないのだろうか」の問いに対し，日本の中学校，高等学校の教科書，フランスの中学校の教科書におけるオームの法則の扱いの比較を行い諸視点からの考察を加え，本学での教育実習前後の指導方法を検討した。日本の教科書では中学校から高等学校まで全てIV グラフであり，中学校の実験はすべて帰納的であるのに対し，高等学校では検証実験としての位置づけがされていた。一方，フランスの教科書では全てがVI（電圧−電流）グラフであり，V=RI の式を用い，R を比例定数として扱っていた。また，抵抗に関する具体的なイメージを与えた後にオームの法則を扱い，R をV とI の関係からも理解させる流れであった。一部の教科書では検証実験として扱っていた。日本の場合，学習指導要領解説に沿って金属線（電熱線）の実験が前提とされ，独立変数と従属変数の指導の文脈などからもIV グラフを必然とする理由があった。そして、諸視点を踏まえるなら，VI グラフの指導はあってもよいと結んだ。学生が教育実習から戻り，他の学生と共有する際のディスカッションを深める教材として，本報告を用いることとした。departmental bulletin pape
Materials to Learn Cutting-Edge Data Science in English for Students Science in Science and Engineering
Full text linkapplication/pdfTo prepare for diverse career paths, students have to learn diverse fields of science and engineering. Education a student receives in a Japanese university, however, is limited to what the faculty and the department he/she belongs to offer. The number of instructors belonging to one faculty or one department is quite limited in most Japanese universities, when compared to those in the US or in Europe. This shortcoming has been preventing students to learn and be trained in emerging new fields in the neighboring fields.
Among leading universities there is another implicit pressure among students studying mathematics a nd physics t hat t he “ best” m athematics a nd physics t ake t he “pure a nd simple” forms. This way of thinking has been formed in the earlier half of the 20th century when several revolutionary ideas have been proposed. For example, the 4-color theorem in mathematics was proven by the team who had better access to multiple IBM-370, the super-computers in mid 1970s
than competitors1 ). The dream proof of Fermer’s theorem took hundreds of pages（. 1: Robin Wilson: Illinois Journal of Mathematics Vol 60（2016）, pp 149-178）
In particle physics the super-string theory has been attracting many talented scientists worldwide.
No body yet sees the ultimate theory.
Meanwhile, fields including astrophysics, medicine, molecular and biological sciences have become to rely heavily on data analyses. The data come either from observations, measurements, or simulations.
Many developments in data science came out of physics: the famous Fermi-Pasta-Ulam note led to the theory of solitons, the KAM theory and machine learning algorithms. Feynman-Kac formalism is based on the path-integral in quantum mechanics. It finds hundreds application in the fintech field. Sadly, many physicists and mathematicians do not know about these developments.
The teaching material have been prepared to catch attention of students and instructors in the fields of science.departmental bulletin pape
Study of human behavior in the waterside space in urban area Focus on the Motomachi Bank of the Ota River
Full text linkapplication/pdfThe Motomachi Environmental Embankment is located upstream from Karasaya Bridge in the Motomachi district on the left bank of the old Ota River, and was completed in 1983. It is characterized by the poplar trees that stand on the embankment. It is a highly hydrophilic, open space with a beautiful view, and is loved by local residents as a place to relax and also used as a venue for holding
events.
The author used a human flow survey to clarify how this waterfront space is used and whether there are any changes in usage due to the development of surrounding facilities.departmental bulletin pape
Method for Deriving the Position Coordinates of the Contact Point between a Celt and a Table in a Celt-Fixed Coordinate System
Full text linkapplication/pdfA celt, a type of boat-shaped top, rotates while rapidly changing the position of the contact point with the table. In this paper, we propose a method to derive the coordinates of the contact point between the celt and the table in a celt-fixed coordinate system from the Euler angles obtained by an IMU. The author confirmed that when a spin rotation is given in the strong reversal direction, a large elliptical contact point trajectory is drawn in the section from after release to the maximum spin angular velocity, and a linear contact point trajectory is drawn after the maximum spin angular velocity. We were able to directly observe from the sensor's angle data that roll vibration is dominant in the section from the first maximum spin angular velocity to the minimum spin angular velocity, and that pitch vibration is dominant in the section after the minimum spin angular velocity.departmental bulletin pape
Verification of the necessity for a remedial mathematics program on proportions
Full text linkapplication/pdf数学リメディアル教育における「割合」の単元の必要性について、地方私立大学と日本の教育の現状に基づいて検討する。割合の単元は小学校算数においても教育が困難な単元であることが認識されており、大学の理工系教育にも影響を与えている。割合をリメディアル教育として取り扱うことの是非を検討することそのものも重要であるが、なぜ学生たちが割合を苦手としているのかを検証し、大学生の数学基礎力向上への糸口を探る。本研究では大学において割合をどの程度学び直す必要があるのかをまず明らかにするため、割合に関する理解度の調査と解説授業の作成を行った。調査の結果、大学生の基礎的な割合の問題の正答率は高いものの、読解を必要とする問題や単位変換などの応用問題への対応に課題のある現状が明らかになった。解説授業は公式暗記に基づく知識を図解に基づく理解に切り替えることに重点をおいて実施し、事後の確認テストにおいて割合に対する理解度の向上を暫定的に確認した。departmental bulletin pape
EdTech Trends and Prospects at the BETT Asia2023 Conference
Full text linkThis study examines the trends and prospects for BETT Asia, a conference for EdTech products and
services in the Asian region. In total, there were 22 sessions. Both the primary and higher education
sessions had the most content on innovation. There were 48 exhibitors. The overall trend was to offer
more management systems than new hardware. Generative AI was already being implemented as
part of services. Many companies are selling EdTech products and services globally, offering services
to visualise different types of educational data in schools. There is little new hardware available
for coding and teaching STEAM. However, companies are expanding their educational content and
curricula to include robotics. In Japan, the issue is how to effectively handle learning data as a means
for personalized and optimal learning. Therefore, the dashboard functionality and system design of
the companies exhibiting at the conference will serve as a reference for research targeting education
in Japan.departmental bulletin pape
High school-university collaboration based on STEAM education —Generation of beautiful geometric shapes using Python—
Full text linkapplication/pdfSTEAM教育に基づく高大連携において、Pythonプログラムを用いたコンピュータグラフィックスにより美しい幾何学図形を生成する授業教材を開発し、授業とグループワークを実施した。幾何学図形は、定規と歯車を使って美しい図形を描く子供用玩具のスピログラフをコンピュータ化し、複数の歯車を自由な回転スピードで連結して図形を生成できるようにしたものである。教材の中には、三角関数に基づく図形生成原理、Pythonプログラミング、パラメータの変更による様々な形の生成に関する内容が盛り込まれている。受講した生徒へのインタビュー、生徒が作成した発表会用ポスタの内容、発表会での発表者の発言内容から、美しい図形の創作を通じてコンピュータグラフィックスの技術を学ぶことに対して非常に成功した。幾何学図形と数学との関係を理解させることに対して、やや成功した。departmental bulletin pape