• Journal of Institute of Control, Robotics and Systems
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• v.21 no.12
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• pp.1100-1108
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• 2015

A camera-based real-time hand posture and gesture recognition system is proposed for controlling various devices inside automobiles. It uses an imaging system composed of a camera with a proper filter and an infrared lighting device to acquire images of hand-motion sequences. Several steps of pre-processing algorithms are applied, followed by a background normalization process before segmenting the hand from the background. The hand posture is determined by first separating the fingers from the main body of the hand and then by finding the relative position of the fingers from the center of the hand. The beginning and ending of the hand motion from the sequence of the acquired images are detected using pre-defined motion rules to start the hand gesture recognition. A set of carefully designed features is computed and extracted from the raw sequence and is fed into a decision tree-like decision rule for determining the hand gesture. Many experiments are performed to verify the system. In this paper, we show the performance results from tests on the 550 sequences of hand motion images collected from five different individuals to cover the variations among many users of the system in a real-time environment. Among them, 539 sequences are correctly recognized, showing a recognition rate of 98%.

• Journal of the Korean Home Economics Association
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• v.43 no.8 s.210
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• pp.115-122
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• 2005

The hand performs functions such as grabbing and other movements. In order to accomplish these movements in various kinds of operational environments, appropriate gloves must be worn to protect your hands. Choosing the appropriate type of glove is very important when wearing gloves in these types of operational environments. The reasons one wears gloves varies depending on age and gender. Unmarried women in their early twenties, for example, occasionally wear gloves for decoration rather than for functional reasons. However, previous studies examined a range of topics, and as such investigations dealing with specific body shape and demands of consumer are needed. Therefore in this study, the hands of unmarried women ranging in age from 20 to 24 were measured and hand shape types were analyzed in order to present basal data which can be used to help design improved glove patterns and produce appropriate, functional gloves. A total of 261 Korean women were measured. Fifty-seven right hand dimensions were measured and five dimensions from both hands were measured. Six factors were identified through factor analysis and those factors constituted $73.259\%$ of total variance. Two clusters of hand shapes were categorized using 6 factor scores by cluster analysis. Type 1 hand shape is defined as long hands with small width, girth, and thickness, long and thin fingers, and high vertical palm height. Type 2 hand shape is defined as short hands with large width, girth and thickness, short fingers, thick knuckles, and short vertical palm height. The characteristics of type 1 and 2 hand shapes are similar to women's hand type classification results from previous reports, but there was a significant difference in subject distribution by type. Therefore, standard data on hand shapes should be produced by developing measuring instruments and selling more accurate standard measuring points. By doing this it could help in the development of improved glove patterns, and also aid in planning production based on hand type.

• Journal of the Ergonomics Society of Korea
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• v.27 no.3
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• pp.1-6
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• 2008

Individual finger/total grip forces, and subjective preferences for various individual finger grip spans (i.e., four fingers had identical grip spans or different grip spans) were evaluated by using an "Adjustable Multi-Finger Force Measurement (MFFM) System". In this study, three grip spans were defined as follows: a 'favorite grip span' which is the span with the highest subjective preference; a 'maximum grip span' which is the span with the highest total grip force; a 'maximum finger grip span' which is a set of four grip spans that had maximum finger grip forces associated with the index, middle, ring, and little fingers, respectively. Ten males were recruited from university population for this study. In experiment I, each participant tested the maximum grip force with five grip spans (45 to 65mm) to investigate grip forces and subjective preferences for three types of grip spans. Results showed that subjective preferences for grip spans were not coincidence with the performance of total grip forces. It was noted that the 'favorite grip span' represented the lowest total grip force, whereas the 'maximum finger grip span' showed the lowest subjective preferences. The individual finger forces and the average percentage contribution to the total finger force were also investigated in this study. The findings of this study might be valuable information for designing ergonomics hand-tools to reduce finger/hand stress as well as to improve tool users' preferences and performance.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.53-60
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• 2019

Objective: The purpose of this study was to investigate the differences of smoothness and coordination of the fingers and upper extremities between skilled and non-skilled players during receiving the basketball. Method: Ten male recreational basketball players (age: $23.2{\pm}2.7yrs.$, career: $8.6{\pm}1.6yrs.$, height: $177.3{\pm}6.0$, weight: $72.9{\pm}8.5kg$) careering over five years and ten non-skilled males (age: $27.3{\pm}1.5yrs.$, height: $173.7{\pm}5.6$, weight: $73.2{\pm}12.6kg$) were participated in this study. Then, participants were asked to perform basketball receiving movement for ten times. The receiving movements were recorded by eight infrared cameras (Oqus 300, Qualisys, Sweden). The collected rad data were calculated to duration of basketball receiving, Jerk-Cost, CRP and CRP variability. Results: The CRP of MCP-Wr, Wr-El in skilled group were greater than non-skilled group (p<.05). The CRP variability of El-Sh in non-skilled group was greater than skilled group (p<.05). Conclusion: These results suggest that skilled players perform more effective movement for impact absorption from the basketball. Moreover, the skilled players have consistent movement patterns during basketball performance. Lastly, it is important to train finger sensation and cognitive ability of thrown basketball from the passer.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1285-1288
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• 1997

The basic technology of virtual reality can be described as the cognition of the condition change in virtual world by stimulating the visual, auditory, kinesthetic and tactile sensation. Among these, the kinesthetic and tactile sensation is one of the most important things to recognize the interaction. In this paper, it is addressed the haptic device which help the human feel the sense of the operator, and is designed in modular type to expand for five fingers later. the haptic device is driven by tendon and ultrasonic motors located in the wrist part. Each joint is actuated by coupled tendons and adopts more actrator by one than the number of the joints, called 'N+1 type'. The haptic device adopts metamorphic 4-bar linkage structure and the length of linkages, shape and the location of joint displacement sensor are optimized through the analysis.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.9
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• pp.720-726
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• 2003

A virtual keyboard may be efficient as a new mobile input device supporting QWERTY keyboard layout. As a preliminary study for developing a virtual keyboard, the typing pattern of a skilled human is investigated. In the study the touch-positions of the fingers are measured with a touchscreen while five skilled typists perform typing of long sentences. From these measurements it can be observed that the groups of touch-positions are classified into alphabetic characters. Though there are some mismatches, we can find constant distances capable of being discriminated among the groups. Based on the analysis the prediction algorithm of the constant distance is proposed and evaluated, which is useful for realization of a portable virtual keyboard.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.138-141
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• 2002

In this paper, we developed a Master Hand which has 20 potentiometer for getting grasping data of human hands, a Slave Hand which has 20 DOF and five fingers with servo-motors, and a controller for the 7 DOF Arm with Multi-fingered hands. And, we programmed a 3D simulation S/W which controls a Robot System with Multi-fingered hands. A developed Robot System showed good performance in the grasping of an object with known position and shape.

• Journal of Biosystems Engineering
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• v.25 no.1
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• pp.19-24
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• 2000

This study was carried out to develop gripper which to adaptive variable tray and to develop automatic transplanting system for seedling-production system between tray. This system consisted of five set of gripper and end-effector, a planting-width control unit, a tray transfer unit, and gripper moving device which move gripper between nursing tray and growing tray. This system used push-out rod to grasp plant instead of pull-out end -effector. Several types of fingers, which physically grip seedlings, were also developed and tested to ensure reliable transplanting operation of the gripper. The transplanting system detaches seedlings from a tray with push-o0ut rods, which were installed under the tray transfer unit. The performance of the transplanting system was evaluated by successive transplanting experiments. Using the best type of finger , the transplanting system produced 94.6% of transplanting success rate.

• Journal of Preventive Medicine and Public Health
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• v.27 no.4 s.48
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• pp.763-776
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• 1994

Recent studies reveal that grip forces during the hand-arm vibration are most significant for the genesis of vibration-induced white linger syndrome. Therefore, exerted grip forces and skin temperatures of fingers were regarded as dependent variables in experiments and the effects of grip temperature, noise, pushing force, vibration and the combined effect of vibration and pushing force were studied. The objectives of the present study were, first, to varify and compare the changes of grip force affected by grip temperature, noise, pushing force, vibration and the combined effect of vibration and pushing force and, second, to observe the reaction of finger skin temperature affected by above factors. Forty-six healthy male students ($25.07{\pm}2.85$) participated in five systematically permuted trials, which endured 4 minutes each other. Experiments were executed in a special chamber with an air temperature of 21C. In each experiments, the subjects were exposed to five experiment types: (1) grip force of 25N only, (2) pushing force of 50N, (3) acceleration of vibration $7.1m/sec^2(z-direction)$, (4) pink noise of 95 dB (A) and (5) combination of pushing force 50N and acceleration of vibration $7.1m/sec^2$. A repeated-measures analysis of variance (ANOVA) was performed on the grip force to test whether it was affected by noise, pushing force, vibration and pushing force. The present results show that vibration was significantly related to the increase of grip force, but the other factors, such as pushing force, noise and grip temperature had no signigicant influence on the increase of grip force, and that the reaction of finger skin temperature were significantly affected by the skin temperature at start of experiment and grip temperature, not grip force and other experimental conditions. Therefore, we suggest that the management for decreasing the grip force is meaningful to prevent the occurrence of Hand-arm vibration syndrome (HAVS).

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.6
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• pp.807-815
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• 2015

The present study aimed at evaluating the intensity of Tifton 85 conditioning using a mower conditioner with free-swinging flail fingers and storage times on dehydration curve, fungi presence, nutritional value and in vitro digestibility of Tifton 85 bermudagrass hay dry matter (DM). The dehydration curve was determined in the whole plant for ten times until the baling. The zero time corresponded to the plant before cutting, which occurred at 11:00 and the other collections were carried out at 8:00, 10:00, 14:00, and 16:00. The experimental design was randomised blocks with two intensities of conditioning (high and low) and ten sampling times, with five replications. The high and low intensities related to adjusting the deflector plate of the free iron fingers (8 and 18 cm). In order to determine gas exchanges during Tifton 85 bermudagrass dehydration, there were evaluations of mature leaves, which were placed in the upper middle third of each branch before the cutting, at every hour for 4 hours. A portable gas analyser was used by an infrared IRGA (6400xt). The analysed variables were photosynthesis (A), stomatal conductance (gs), internal $CO_2$ concentration (Ci), transpiration (T), water use efficiency (WUE), and intrinsic water use efficiency (WUEi). In the second part of this study, the nutritional value of Tifton 85 hay was evaluated, so randomised blocks were designed in a split plot through time, with two treatments placed in the following plots: high and low intensity of cutting and five different time points as subplots: cutting (additional treatment), baling and after 30, 60, and 90 days of storage. Subsequently, fungi that were in green plants as well as hay were determined and samples were collected from the grass at the cutting period, during baling, and after 30, 60, and 90 days of storage. It was observed that Tifton 85 bermudagrass dehydration occurred within 49 hours, so this was considered the best time for drying hay. Gas exchanges were more intense before cutting, although after cutting they decreased until ceasing within 4 hours. The lowest values of acid detergent insoluble nitrogen were obtained with low conditioning intensity after 30 days of storage, 64.8 g/kg DM. The in vitro dry matter of Tifton 85 bermudagrass did not differ among the storage times or the conditioning intensities. There was no fungi present in the samples collected during the storage period up to 90 days after dehydration, with less than 30 colony forming units found on plate counting. The use of mower conditioners in different intensities of injury did not speed up the dehydration time of Tifton 85.