小方 博之

Abstract The injection molding market is expected to grow with the increasing demand from various industries, such as automotive and furniture. However, weld lines in the injection molded part reduce the structural strength and affects its appearance. This study evaluates the effect of the weld line on the structure by shifting the position of the weld line outside the area where the load is applied by manipulating the opening time of the injection gates. We examined the effect of weld lines on the strength of a chair through coupled resin flow and structural analyses. The analysis revealed that the position of the weld lines is crucial for structural strength if the knockdown factor (KDF) is low. Additionally, controlling the opening time of the gate and shifting the position of the weld line improved the structure's appearance, number of weld line and avoid the lower meeting angle. However, depending on the material, the effect may be weak. For example, when the weld line location did not change much despite changing the gate timing, little change was observed in the number of weld lines. Hence, the improvement strategy of weld line should be considered for material types and strength. Highlights Injection molding growth driven by automotive, packaging, furniture demand. Weld lines impact structural strength and appearance. Shifting weld line position outside load area improves the structural appearance and strength. Effects of shifting weld line position depended on the material types. Weld line position is crucial for low knockdown factor and affects strength.

農地内で様々な植物種を混生密生状態で生育させる協生農法環境下では植物同士の区別が難しく，管理のための自動化が課題となっている．本プロジェクトでは，協生農法の鍵である植生の多様性を維持するために，特定の植物が他の植物種に対して過度に繁茂している状態を優勢状態と呼び，優勢状態の植物は剪定する．本論文では，農園の俯瞰カメラから取得した RGB 画像を用いて特定の植物種を対象に，優勢状態の推定を行うことを目的とする．本研究の提案手法としてはまず，RGB 原画像を分割小領域に分割し，各分割小領域内の植物種数を，VGG16 を用いて推定する．植物種数が“2 種類以下”と推測された分割小領域の数の合計が閾値を超えた場合，原画像は優勢状態の候補と判断する．優勢状態の候補とされた場合，“2 種類以下”と推測された分割小領域間でAKAZE 特徴量を用いて類似度を求め，それらが類似している場合は，同じ植物が繁茂しているとみなして優勢状態と判定する．本手法によって優勢状態の推定では高精度の結果を得ることができ，有効性を確認した．

スキーは時期や場所の制限が厳しく, 転倒などの怪我のリスクが高いため, 他のスポーツと比べて初心者が始めるにはハードルの高いスポーツである. そこで本研究では VR とハードウェア技術を統合したスキーのトレーニングシステムを開発し,その有効性を実験により評価する. 具体的には「体性感覚の変化を VR 映像としてフィードバックするシステム」「体性感覚の変化をゲージの増減によりフィードバックするシステム」のフィードバック手段が異なる 2 つのシステムのトレーニング効果を検証, 比較することにより，スキーの学習システムにVR 技術を組み合わせる方法の有効性の見通しを得た.

The current stage of the development of academic systems for education in robotics may be considered to be at a threshold. In order to formulate academic systems for robotics education, researchers need to evaluate the effectiveness and influence of robotics education, objectively or quantitatively, in their research studies. In this study, the authors quantitatively evaluated the educational effects of a robotics classroom for elementary school children in the 5th and 6th grades using psychological measure and statistical analysis. Pre- and post-questionnaire surveys were conducted using a questionnaire that had been used and validated in other studies, and two-factor analysis of variance was applied to the results of the questionnaire. From the results, the following findings are reported. (1) The interest in making things by the group who had little experience making things increased more than the group who did have such experience. (2) The boys group generally had more interest in making things than the girls group. (3) Participants in the 5th grade had greater willingness to do something creative, and in acquiring the skill to use a tool, than did those in the 6th grade. (4) Participants in the 6th grade wanted to create something more specific than did those in the 5th grade. Overall, it was quantitatively shown that the children participating in the robotics classroom originally had a high interest in making things. Moreover, their interest in making things improved through their participation in the robotics classroom.

This paper discusses on a scoring method of list response question of which response is a list of elements, and the elements are completely ordered. List response questions include questions such as sequencing and application-operation type. Few papers focus attention on efficient scoring method when the correct answers are combinationally redundant, or on scoring method considering seriousness of mistakes. This paper deals with these problems in the case that the dissimilarity criterion is used for scoring. To realize an efficient scoring when plural correct answers exist, a method to construct a scoring operation graph from the correct answers and the examinee's answer, and to reduce it to solve the minimal cost problem is proposed. A heuristic function to solve the minimal cost problem using A* algorithm is also presented. When considering the seriousness of mistakes, deciding the degrees of penalty is an important problem. Here, we consider estimating the degrees from human scores, and decided them using regression model. A cooking task is taken for an example to verify the validity of our method.

CBTシステムの研究・実用化が進展するにつれ,自宅受験も技術的に可能になってきている.しかし,自宅受験の場合は,試験監督の監視が行き届かない.そのため,会場受験と比較した場合,受験者にとって不正行為が容易であり,それが自宅受験実現の阻害要因となっている.そこで,本論文では,不正行為の一つである替え玉受験の防止に向けて,ペン持ち方認証におけるなりすまし耐性の強化を図り,その評価を行う.本研究では,替え玉防止のために,筆記時のペンの持ち方が個人ごとに異なることを利用した個人認証法に着目する.具体的には,試験実施中の受験者のペンの持ち方をカメラで撮影し,そこから抽出した複数の特徴を用いて個人認証を行う.替え玉は個人認証を突破するため,正規受験者と協力しながらその持ち方を意図的に模倣して試験に臨むと考えられる.そこで,本論文ではそれを踏まえて実際に替え玉役の被験者に,正規受験者役の被験者の持ち方を練習してもらうことで,協力関係による強い攻撃を考慮したデータを新たに収集した.そして,なりすまし耐性を強化した手法を提案するとともに,既存手法との比較によりその耐性の評価を行ったので報告する.

Project based learning (PBL) is an effective method for education to make students put their knowledge into practice or to train solving problem by themselves. PBL is also recognized to be effective and popular in robotics and manufacturing educations. However, it is not guaranteed that traditional scoring methods, like final exam, are proper to assess students' activity in PBL. One of the noteworthy methods that may be suitable to assess their activity there is the peer assessment. The benefit of carrying out peer assessment is that it has effects on building students' motivation, making feedback, and grading reliably. The author conducted peer assessment in a mobile robot development project in his own laboratory, and in a certain class where students are requested to make a paper bridge as light as possible but can support a 300[g] weight. In this paper, the data of peer assessment in those projects are analyzed to verify its effectiveness.

Recently, e-assessment has become popular, and it is now technically possible for people to take exams at home. However, because the testing environment is dramatically different from the traditional one, new technologies are required to prevent cheating. Many studies have addressed testing environments where a keyboard and mouse are used as input devices, but few have focused on an environment using tablet computers, which are widespread nowadays. The aim of our study is to develop a method of detecting impersonation using touch gestures on a tablet computer. We verified that tap gestures performed by different people on a tablet computer can be distinguished by extracting some features from finger tapping images. An experiment using 30 subjects was conducted for verification. © 2013 IEEE.

Writing is one of a behavior that can be used for biometric person authentication. A popular modality associated with writing is online signature verification. Online signature verification makes use of a trajectory of pen movement as a feature of writing. Though the trajectory is useful to verify signature, it occupies only a small part of writing features. In this paper, we propose a person authentication method using features extracted from pen holding style, which represents another aspect of writing. The features of pen holding style extracted in this paper are derived from both the hand's behavior and the hand's nature. Pen holding style is captured by a camera, and those features are extracted from the captured image. Dissimilarity scores are calculated from the features, and then combined in score level. In order to evaluate accuracies of proposed pen holding style verification, data from 30 persons are collected. The experimental results show that the proposed algorithm achieves the equal error rate (EER) of 2.7% against others' data, and EER of 4.1% against impersonation data.

The manner of holding a pen is distinctive among people. Therefore, pen holding style is useful for person authentication. In this paper, we propose a biometric person authentication method using features extracted from images of pen holding style. Images of the pen holding style are captured by a camera, and several features are extracted from the captured images. These features are compared with a reference dataset to calculate dissimilarity scores, and these scores are combined for verification using a three-layer perceptron. Preliminary experiments were performed by using a private database. The proposed system yielded an equal error rate (EER) of 2.6%.

人は筆記する際にペンを持つが,ペンの持ち方には個人性が現れると考えられる.そこでペンの持ち方特徴に注目し,これらを用いた個人認証手法の可能性について検討する.本速報では10人から取得したデータを用いた初期実験結果を報告する.

The progress of information technology and the popularization of the personal computer brought the growth of computer-based testing (CBT), which utilizes computer to hold an exam and rate examinees. Most of the current CBT can be regarded as an extension of the paper-and-pencil exam, and aim to assess the knowledge or the achievement of the examinees. On the other hand, very few CBT systems address assessing examinees' skill in sports or manufacturing. This paper discusses a method to evaluate examinees' physical skill from their motion data, taking golf putt swing as an example. The motion data is generally represented as a vector time series. The recurrent neural network is introduced to deal with such data. We verified the effectiveness of the proposed method by collecting actual examinees' motion data and assess them using the proposed method.

Generating motion is important for the robots over doing some kind of task. Especially, generating motion to cover certain area utilizing the size of the robot is used to realize robotic tasks, such as sweeping floors. Most of these robots generate their motion by reactive algorithm with easy sensors mounted. However, with these algorithms, the sweeping task would be done uneven to the sweepable areas. So, there are still rooms for developing a more efficient algorithm. To develop an efficient algorithm, evaluation method is in need. However, the methodology to evaluate the efficiency of state informed algorithm has not yet established. Cleaning robots do not always clean the same environment so, the difficulty of this research is that consideration of various kinds of environments is needed. The chapter develops sweeping robot simulator to analyze the existing sweeping algorithms and reveal their inefficient features to improve the existing algorithms. The algorithms that commercial robot cleaners install are analyzed, and those efficiencies are estimated. © 2006 Elsevier Ltd. All rights reserved.