Shinji Ozawa

Following vehicle detection using multiple cameras

In recent days, various in-vehicle camera systems have been proposed for detecting following vehicles. In this paper, we propose a vehicle detection method based on feature points. First, the feature points are detected from the image obtained from the camera and the optical flow is calculated by tracking the feature points across the image sequence. Then the feature points are assumed to be coplanar and to model the front of the following vehicle. This planes movement can be defined by an affine-transformation, and the optical flow of the plane is used to determine whether a section of the image is in the background or is part of the following vehicle. By extending previous detection systems based on edge models to include feature point tracking, our method is able to produce improved detection of following vehicles. To verify the accuracy of our method, we have performed experiments in a variety of different road conditions and situations. As a result, the proposed system is expected to be useful for reducing traffic accidents caused by rear- and/or side-located vehicles.

Effect Analysis of Intelligent Speed Adaptation (ISA) in Advisory Mode on Community Roads

Abstract ISA is considered as an effective measure to reduce traffic accidents. To make the possibility analysis, an experiment is conducted by using a driving simulator. The outputs from the simulator are analyzed combined with the ages and road conditions. The experiment shows that the ISA can improve recognition to speed limitation and drivers’ behavior. Furthermore, drivers react significantly to voice assisted ISA; audible advisories by the ISA such as reduction of speed are acknowledged by drivers concluding positive effects on traffic safety.

Performance evaluation of error-correcting scheme without redundancy code for noncoherent chaos communications

This paper considers a novel error-correcting scheme exploiting chaotic dynamics for noncoherent chaos communication. In our proposed system, two successive chaotic sequences are generated from the same chaotic map; the second sequence is generated with an initial value which is the last value of the first sequence. In this case, successive chaotic sequences having the same chaotic dynamics are created. This feature gives the receiver additional information to correctly recover the information data and thus improves the bit error performance of the receiver. Further, enhanced efficiency also comes from operating on successively modulated data; by involving less redundancy in the error correction system, it can be designed with high coding rate. In this paper, we analyze the schemes capability, by examining computational times and accuracy rates of error correction, bounds on its capability.

Following vehicle detection based on shift of feature plane using affine transform

This paper proposes a novel vehicle detection system based on shift of a feature plane, which consisted of feature points on a front surface of vehicle, using in-vehicle camera for following vehicles observation. We find that the feature plane of the vehicles front surface shifts in accordance with the affine transform. We perform experiments and evaluate performances of our system. As results, we confirm that our system can locate and track the rear and side vehicles accurately and robustly.

A study on motion analysis of an artistic gymnastics by using dynamic image processing - for a development of automatic scoring system of horizontal bar -

This research introduces an automatic scoring mechanism based on motion analysis of a player by video image processing and database of skills in gymnastics. The automatic scoring system will be made for the horizontal bar which is one of the gymnastics in particular. A scoring result is equivalent to scoring until now according to experience of a referee and the rulebook, or in order to perform highly precise scoring, it does not use the standard of scoring only with defined performance figure or a text. It is the new approach of this research to describe them as a program to be the databases which analyzed them. The result of this research considers scoring of a referee as a correct answer. Thereby, evaluation of a system can be performed, and if the system performance is enough, it will be considered to be useful that it can use for evaluation of a referee etc.

An Automatic Broadcast System for a Weather Report Radio Program

Here we describe a speech-synthesis method using templates that can generate recording-sentence sets for speech databases and produce natural sounding synthesized speech. Applying this method to the Japan Broadcasting Corporation (NHK) weather report radio program reduced the size of the recording-sentence set required to just a fraction of that needed by a comparable method. After integrating the recording voice of the generated recording-sentence set into the speech database, speech was produced by a voice synthesizer using templates. In a paired-comparison test, 66% of the speech samples synthesized by our system using templates were preferred to those produced by a conventional voice synthesizer. In an evaluation test using a five-point mean opinion score (MOS) scale, the speech samples synthesized by our system scored 4.97, whereas the maximum score for commercially available voice synthesizers was 3.09. In addition, we developed an automatic broadcast system for the weather report program using the speech-synthesis method and speech-rate converter. The system was evaluated using real weather data for more than 1 year, and exhibited sufficient stability and synthesized speech quality for broadcast purposes.

Effects of Intelligent Speed Adaptation on Elderly Drivers’ Driving Behaviors and Mental Workloads

This study investigates the potential impacts of implementing mandatory and advisory intelligent speed adaptation (ISA) for elderly drivers driving on neighborhood streets. Using a driving simulator, driving behaviors such as vehicle speed and position of the gas pedal were analyzed. In addition, the mental workloads that could be represented by pupil dilation were measured using an eye camera device. Because elderly drivers tended to drive below the speed limit, implementation of ISA had little effect on reducing the speed driven at on neighborhood streets by elderly drivers. However, the implementation of ISA did serve to significantly reduce the mental workload for elderly drivers.

Template-based methods for sentence generation and speech synthesis

Here we propose a sentence-generation method using templates that can be applied to create a speech database. This method requires the recording of a relatively small sentence set, and the resultant speech database can generate comparatively natural sounding synthesized speech. Applying this method to the Japan Broadcasting Corporation (NHK) weather report radio program reduced the size of the required sentence set to just a fraction of that required by comparable methods. We also propose a speech-synthesis method using templates. In an evaluation test, 66% of the speech samples synthesized by the proposed method using templates were preferred to those produced by the conventional concatenative speech-synthesis method.