Chiba Institute of Technology

About: Chiba Institute of Technology is a education organization based out in Narashino, Japan. It is known for research contribution in the topics: RNA & Magnet. The organization has 2663 authors who have published 4999 publications receiving 56870 citations. The organization is also known as: Chiba kōgyō daigaku & Kōa Institute of Technology.

Role of Emoticons for Multidimensional Sentiment Analysis of Twitter

Abstract: Microblogging systems such as Twitter and Facebook have become popular. People can easily post their sentiments to the Internet in real time using such microblogging systems. Twitter is a text-based communication tool. Users cannot use non-verbal communication tools such as gestures and eye contact on Twitter. Users sometimes use emoticons as an alternative non-verbal communication tool to tweet delicate sentiments. In this paper, we propose a method of determining sentiment of a tweet based on the emoticon role. Specifically, we propose the following: (1) compilation of a sentiment lexicon and an emoticon lexicon; (2) emoticon roles can be classified into four types showing "Emphasis", "Assuagement", "Conversion", and "Addition", with roles determined based on a relation between sentiments of sentences and emoticons; and (3) the relation can be formalized using regression analysis in all roles excepting for "Addition".

Novel straight road driving control of power assisted wheelchair based on disturbance estimation and minimum jerk control

Abstract: Power assisted wheelchair which assists the driving force by electric motors is expected to be widely used as a mobility support system for elderly people and disabled people. In the practical driving condition, the straight driving can be prevented by the road conditions such as branches, grass and carpets because the right and left wheels drive independently. This paper proposes a novel straight road driving control system based on the disturbance torque estimation. The proposed system estimates the driving torque difference between the right and left wheels by disturbance observer and compensates to one side of the wheels. This paper also describes a minimum jerk trajectory control for power assisted wheelchair to improve the ride quality and safety. Some practical experiments on the various practical roads show the effectiveness of the proposed control systems and the possibility for the multi purpose and high performance system of power assisted wheelchair.

Loss Analysis of Permanent Magnet Motors with Concentrated Windings - Variation of Magnet Eddy Current Loss Due to Stator and Rotor Shapes

Abstract: In this paper, we investigate losses including magnet eddy current loss of permanent magnet synchronous motors with concentrated windings. The 3-D finite element method considering the carrier harmonics of PWM inverters is utilized to calculate the losses in each part of the motor separately. A simple linear magnetic circuit modeling is also introduced to understand the mechanism of the magnet eddy current loss generation. First, the measured and calculated results are compared to verify the validity of the analysis. Next, the variation of the losses due to the stator and rotor shapes are investigated, for instance, concentrated and distributed stator windings, interior and surface mounted permanent magnets. It is clarified that the eddy current loss of the permanent magnet in the concentrated winding motor is much larger than the distributed winding motor. The difference of the loss generation mechanism due to the rotor shape is also clarified.