In this paper, we propose a method for presenting surface shapes, including curve-shaped asperity and textures of objects. In our previous research, we focused on the surface shape and texture of objects and proposed a method for presenting surface shape with polygon-shaped asperity and texture; therefore, this earlier method cannot represent surface shapes with curve-shaped asperity. To represent such asperity, a virtual surface is constructed by combining multiple sinusoidal waveforms. By tracing the constructed virtual surface using a haptic interface, a user can feel various types of reaction force based on defined parameters of the sinusoidal waveforms, skin friction, and stiffness of the virtual surface. Furthermore, we develop a system for Kansei evaluation that presents a user with a virtual tactile sense based on reaction force using the proposed method. Evaluating Kansei from tactile feelings using the developed system is beneficial in developing products touched by humans. Experimental results indicate the effectiveness of the proposed method and the potential of the developed system for Kansei evaluation.
Families of t-norm based histogram intersections and a corresponding content-based image retrieval system are proposed. It is shown that the retrieval performance varies depending on the semantic category of the image and the usage of different t-norms results in a performance increase. Computational costs are determined as both the complexity and the average of 106 calculation times needed to calculate each similarity on a personal computer. To evaluate retrieval performance, precision and recall on the Corel image databases are determined, and Friedman test and Scheffe′s method are used to find difference between similarity measures. The results suggest that the proposals have the best average Friedman ranks in some categories (implying improved precision) having only 125 ms overhead when compared to the basic histogram intersection. Due to observed performance of families of t-norm based histogram intersection, system performing boosting of such norms could increase the overall accuracy in content-based image retrieval.
Recent commercial products tend to have various appearances with curved surfaces. This is because attractive outer designs stimulate consumers' motivation for purchasing. This paper attempts to study how the bottle shapes affect our impression. The approach consists of three parts. First, three-dimensional models are fabricated to imitate shapes of widely circulated PET bottles, and thirty five examinees rate their impression by answering questionnaires. Measured objects have nine different bottle shapes with specific features. Twelve adjective pairs are chosen for the use in questionnaires to describe model features. Then, the results from the questionnaires are studied by the analysis of variance to clarify the significant differences among impressions caused by variously curved shapes. Finally, the results are analyzed by using the factor analysis to get the factor scores.
Shadow letters refer to subjectively-perceived letters that lack actual contours, but have illusory contours acquired as a result of shading. This study aims to examine the colorimetric factors affecting the evaluation of impressions of chromatic shadow letters on the basis of the corresponding relationship between psychological evaluation and colorimetric values. In the impression rating experiment, twenty participants rated the impressions of - conspicuousness, legibility, and three dimensionality - of each letter string on a 7-point scale. It was inferred that the rating values increased when the participants observed differences in hues or tones between the colors of the shadow and background. Further, the colorimetric values of the stimuli between the colors of the shadow and background were evaluated based on the color measurement. An analysis of the correlation between the psychological rating values and the colorimetric values of the stimuli revealed that the impression strength of the shadow letter strings was largely dependent on the color difference.
This paper proposes a new method for presenting force feedback based on virtual reality in human-machine systems, such as knobs, to evaluate the usability of knobs for manipulating devices. If the force feedback is known, a user can detect features such as the mass of the knob, friction of the shaft, and so on. Furthermore, the conditions for designing virtual knobs are utilized evaluation of the usability of knobs based on users' affections. Experimental results indicate that particular relationships exist among some Kansei words. In addition, the effectiveness of Kansei evaluation using the proposed system is confirmed through a comparison of evaluation result of virtual knob and real knob.
Impression of silhouette of products which can be divided into an upper and a lower parts is discussed. In this paper, it is assumed that an upper and a lower parts of products can be approximated to two rectangles, and experiments were carried out in order to verify the impressions of figures which consist of two rectangles. Various combinations of rectangles were shown to the subjects and the impressions were measured. As a result, the relations between the combinations and impressions, i.e. warm-cool, hard-soft, urban-country, luxury-cheap, friendly-not friendly, and simple-complex, have become clear.