Byungki Jin

The morphology of the polyhedra of a host range-expanded recombinant baculovirus and its parents

SummaryThe host range-expanded recombinant baculovirus, RecB-8 was isolated from BmN-4 cells coinfected with Autographa californica and Bombyx mori nuclear polyhedrosis viruses. Its genome was compared with those of its parents by restriction endonuclease digestion and their polyhedra compared in an electron microscope. Interestingly, the polyhedra of RecB-8 were tetrahedral although the polyhedrin gene was the same as that of the BmNPV parent which has icosahedral polyhedra. Thus the morphology of the RecB-8 polyhedra resulted from host cell factors and/or another viral genome in the host cells.

A Research on Curved Display Comparing to Flat Display Regarding Posture, Tilt Angle, Focusing Area and Satisfaction

Objective: This study is conducted on the differences between flat and curved displays with respect to location of focused points, posture and satisfaction as well as preferred tilt angles. Background: In order to avoid physical and eye fatigue caused by misplayed sitting posture, many studies have asserted that the display requires appropriate location, size and tilt angle as well as curvature. However, most studies have focused on the work environment and the results are varied in the extent. Method: Eye height data in sitting posture were collected from 30 participants. Participants selected the most comfortable viewing angle within the range from 0° to 12° while watching videos for both curved and flat display. Then, physical and eye fatigue and overall satisfaction were subjectively evaluated. Lateral diagram describing viewing display condition was set and used to develop linear models for expecting the preferred tilt angle. Results: Due to sitting in the natural viewing posture rather than upright, the eye height is lowered to about 4.6 centimeters, on average, for both displays showing no significant differences. In contrast, preferred angles for the two displays are significantly different and this can be interpreted that curvature vary the points focused. Two linear models as functions of sitting eye height are developed to expect preferred tilt angle for each display. Based on the result of overall satisfaction evaluation, curved display is statistically better than flat display. Conclusion: The results show that flat and curved displays are significantly different expect for the viewing posture. However, reasons for preferring curved display are not accurately factorized and the linear models are limited in the experiment condition such as size of display, distance between display and viewer and other physical environmental factors. Further studies on curved displays under more various conditions are required. Application: This study can contribute to use of the curved display in various way.

Effects of Grip Curvature and Size of Hand on Comfort for the Unimanual Operation of Handheld Touchscreen Device

This study aims to investigate the effect of size of a hand and curvature of handheld touchscreen devices on comfort when unimanually using the devices. By rated subjectively and recording EMG, comfort was measured for the use of three mock-ups of the device with different curvatures; one had flat surface and the others had curvatures of 400R and 100R for each. During the experiment, tapping, typing and dragging tasks were performed and the participants evaluated comfort subjectively and objectively. A difference among curvatures was analyzed as well as a difference among participant groups classified by size of their preferred hand. The results indicated that curvature of the handheld touchscreen devices affected neither muscle activities nor subjective comfort level. Moreover, size of hand was found to affect comfort objectively measured, but not the one subjectively rated. Overall, this study suggests that comfort measured subjectively does not consistent with comfort measured by objective data. Also, users’ hand size may be more critical factor than curvature of handheld touchscreen determining comfort of touch screen use.

Generating a research keyword structure on human haptic interaction using a social network analysis tool

The field of haptic interaction is inherently multidisciplinary and adopts knowledge from many areas, including robotics, experimental psychology, biology, computer science, systems and control, and others. It is an important first step in research reviewing overall areas of hap-tic related researches, as well as reviewing the specific area of focus. For this purpose, it is important to ensure objective research direction based on the clear and enlightening analysis of the research trends in this field. This study aims to identify the relationship among overall areas of haptic related researches using a network analysis technique. We collected keywords of haptic related researches from several journals and used those as an input for conducting network analysis. Then, we also classified the areas of haptic researches by analyzing the relationship among keywords. From the network analysis, we found that haptic related researches could be classified into two areas; (1) Technology perspectives related to the application of haptic technology and (2) User perspectives related to the perception of haptic sensation. The keyword structure generated from this study is expected to provide basic knowledge on the trend and current status of researches in human haptic inter-action.

Anthropometric Classification of Human Hand Shapes in Korean Population

Hand tools designed without the anthropometric perspective lead to lower performance and safety. This study suggests a statistical hand shape classification with Korean anthropometric data. A total of 321 anthropometric data were used for this study. To investigate hand types, 27 anthropometric hand variables normalized by the stature of each participant and factor analysis and cluster analysis were conducted. As a result, three major factors were deduced: factors of hand breadth, palm length, and finger length. Additionally, four hand types were determined: (a) a spacious hand with short fingers, (b) a hand with short palm with above average fingers, (c) a long palm and fingers, and (d) a narrow hand and short fingers. In the male population, the spacious hand with short fingers type was dominant while the narrow hand and short fingers type was dominant in the female population. These results are expected to be preliminarily utilized in design for the Korean population.

Effect of Automobile Exterior Panel Stiffness on Customers` Affect : Focused on Hood and Door of Mid-Size Passenger Cars

This study attempted to identify the effect of the panel stiffness on the customers’ affect, which was not addressed in the research field of affective engineering. For this, this study derived four affects related to the panel stiffness from literature and pre-experiment: hardness, deform consistency, thickness and satisfaction and prepared a questionnaire to evaluate the affects of the panel. In the experiment, 100 adults in the age of 20-50 participated and evaluated the affects of hood, front and rear door for nine full size and luxury sedans by pressing the panels with their hands. As results, participants’ affect for the panels were significantly different depending on the force-deflection curves of them, and the subjects’ satisfaction of the panels increased as the slope of the curve (stiffness) increases. In addition, it was found that the subjects evaluated the panel with the pressing force up to 14 kgf. The findings of the study can used to increase and control the affective quality of exterior panels on passenger cars.

A study on affective feeling evaluation for automotive wiper switch based on multiple regression model

Recently, newly launched vehicles have been more luxurious than past cars. Also, these cars will be simultaneously satisfied between functional operation and aspect of affective feelings. Accordingly, when developing auto parts, many suppliers should consider between functional operation and affectiveness for drivers. Affective engineering in nowadays is studied to evaluate drivers affective feeling by parts suppliers. Regarding automotive business trends, emotional feeling studies have been increasing. This studys aim is to analyze operational feeling for wiper switch in automotive combination switch module. According to this study, its possible to attract design variables to improve feeling based on various factors. Consequently, its available to confirm feeling improvement through the statistic analysis based on significance probability and measured data of 15 samples. From now on, result of this study will be applied for development of more satisfiable switch after considering evaluation and factors for consumers.