• Journal of the Korean School Mathematics Society
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• v.24 no.1
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• pp.151-172
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• 2021

In this study, I investigated prospective mathematics teachers' perceptions of activities using Wax-paper, a hands-on material (manipulatives), and GeoGebra, a technological tool, in teaching quadratic curves. Twenty prospective mathematics teachers in the Mathematics Education Department of a local university participated in a survey on their perception of the use of hands-on materials and technological tools in teaching quadratic curves. According to the results of this study, prospective mathematics teachers generally preferred the use of technological tools for learning and teaching quadratic curves. Additionally, mathematics teachers thought that the tool helped students develop intuitive thinking through visualizing quadratic curves, enabling the exploration of various mathematical properties, assisting the comprehension of various concepts, and increasing students' interest levels. However, they were concerned about the immature use of technological tools by students or teachers, and recognized that the advantages and disadvantages of using hands-on material and technological tools were complementary. Based on these findings, it is suggested that hands-on material and technological tools should be used complementally in mathematics classes, and the development and dissemination of class materials that are not affected by students' or teachers' ability to use technological tools is important.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.9
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• pp.68-76
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• 1997

This paper presents a system which recognizes dynamic hand gestures for virtual reality(VR). A dynamic hand gesture is a method of communication for a computer and human who uses gestures, especially both hands and fingers. Since the human hands and fingers are not the same in physical dimension, the same form of a gestrue produced by two persons with their hands may not have the same numerical values which are obtained through electronic sensors. In this paper, we apply a fuzzy min-max neural network and feature analysis method using fuzzy logic for on-line pattern recognition.

• Journal of Industrial Technology
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• v.16
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• pp.71-81
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• 1996

This paper discusses a physiological approach motivated by the study of human hands for robot hand force control. It begins with an analysis of the human's grasping behavior to see how humans determine the grasp forces. The human controls the grasp force by sensing the friction force, that is, the weight of the object which is felt on his hand, but when slip is detected by sensing skin acceleration, the grasp force becomes much greater than the minimum force required for grasping by adding the force which is proportional to the acceleration. And two methods that can predict when and how fingers will slip upon a grasped object are considered. To emulate the human's capabilities, we propose a method for determination of as grasp force, which uses the change in the friction force. Experimental results show that the proposed method can be applied to control of robot hands to grasp objects of arbitrary weight stably without skin-like slip sensors.

• Physical Therapy Korea
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• v.25 no.3
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• pp.51-59
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• 2018

Background: Despite muscle latency times and patterns were used as broad examination tools to diagnose disease and recovery, previous studies have not compared the dominant arm to the non-dominant arm in muscle latency time and muscle recruitment patterns during reaching and reach-to-grasp movements. Objects: The present study aimed to investigate dominant and non-dominant hand differences in muscle latency time and recruitment pattern during reaching and reach-to-grasp movements. In addition, by manipulating the speed of movement, we examined the effect of movement speed on neuromuscular control of both right and left hands. Methods: A total of 28 right-handed (measured by Edinburgh Handedness Inventory) healthy subjects were recruited. We recorded surface electromyography muscle latency time and muscle recruitment patterns of four upper extremity muscles (i.e., anterior deltoid, triceps brachii, flexor digitorum superficialis, and extensor digitorum) from each left and right arm. Mixed-effect linear regression was used to detect differences between hands, reaching and reach-to-grasp, and the fast and preferred speed conditions. Results: There were no significant differences in muscle latency time between dominant and non-dominant hands or reaching and reach-to-grasp tasks (p>.05). However, there was a significantly longer muscle latency time in the preferred speed condition than the fast speed condition on both reaching and reach-to-grasp tasks (p<.05). Conclusion: These findings showed similar muscle latency time and muscle activation patterns with respect to movement speeds and tasks. Our findings hope to provide normative muscle physiology data for both right and left hands, thus aiding the understanding of the abnormal movements from patients and to develop appropriate rehabilitation strategies specific to dominant and non-dominant hands.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.117-122
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• 2019

This study aimed to provide the basic data for the prevention of carpal tunnel syndrome by measuring and comparatively analyzing the changes in muscular strength, grasping force, and agility of hands before/after practice, targeting the dental hygiene students taking the scaling practice course. Targeting total 15 students(4th-year) of Dental Hygienics who had no problems with anatomical structure, muscular strength, grasping force, and senses of hands, the muscular strength, grasping force, and agility of hands were measured before/after the scaling practice. The collected data was processed by using the PASW Statistics 18.0(SPSS) Program. In the results of this study, the muscular strength and grasping force of hands were decreased after the practice compared to the ones before the practice. The agility of hands was increased after the practice compared to the one before the practice. Based on such results of this study, it would be necessary to avoid such exhausting hand gestures for scaling, and also to develop the preventive exercise to build up the strength of hands like stretching before/after scaling.

• Journal of the Korean Dietetic Association
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• v.4 no.2
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• pp.235-244
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• 1998

Hand washing is an important component of hygiene program for food handlers. Hands can be a source of direct or indirect contamination of foods with pathogenic microorganisms. In this study, the effectiveness of hand washing methods and the use of 70% alcohol solution against transient skin bacteria was tested in an university foodservice facility. 70% alcohol solution is sprayed for 5 seconds automatically when hands are placed in the dispenser. Samples were taken using swab technique in meat cutting area, vegetable trimming area, and vegetable cutting area: before and after washing hands according to planned methods, and after being sprayed with 70% alcohol solution after washing hands. The bacteriological analysis of total plate counts, coliform, fecal coliform of food handlers' hands was done. Statistical data analysis was completed with Mann-Whitney U test and Kruskal-Wallis model using the SPSS program. The levels of initial contamination of workers' hand were significantly different by the work areas($x^2$=9.156, p<0.01). Workers in the vegetable trimming area had more heavily soiled hands than in the other work areas. Mean of TPC counts and coliform was 8.97×$10^5$ CFU/12.4$cm^2$, 2.93×$10^2$ MPN/12.4$cm^2$ respectively, but fecal coliform was not detected. Transient bacteria were removed from hands after washing and using 70% alcohol solution but were not removed completely. Mean reduction percentage in TPC varied among work areas and ranged from 93.19% to 94.99%, and in coliforms from 97.31% to 100%. A significant difference in TPC was found between before and after hand disinfection (Z=-2.714, p<.01) and between standardized hand washing procedures and un-standardized hand washing procedures(z=-2.301, p<.01). Subjects using the hand sanitizer showed a great elimination of TPC(99.45% reduction), but this effect was valid only after following proper washing procedures. Based on the results, the most effective hand washing method was recommended as the combination of the standardized hand washing procedure with warm-water and use of the 70% alcohol solution. The results can be used to develop hand hygiene programs and training strategies for enhancing hand hygiene practices for food handlers in foodservice operations.

• The Research Journal of the Costume Culture
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• v.22 no.5
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• pp.702-711
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• 2014

This study was performed to investigate the hand size growth of Korean adolescents boys. Subjects were between 14 and 19 years (n=352). We collected the right hand size data of 19 measurements from each subject using 3D hand scanner. The total 26 hand measurements were analyzed including seven calculated measurements. Subjects were divided into three age groups (early, middle and late). Their hand size were compared. The results showed that all hand length measurements were significantly difference among age groups. Adolescent boys hands were sharply grown at age 16 years old. The hand dimensions of middle age group were compared with twenties men (n=215). There were significant differences between two groups. The middle age adolescents' hands were shorter and thicker than twenties men. Subjects were also divided by weight and height. Weight and height was closely related to hand size. The heavier and taller subjects had the thicker hand. Their fingers were longer than others. The adolescent boys and twenties men who were taller than the twenties' average height (173.4cm) were compared. Twenties men's hands were longer and thinner than that of adolescent boys. These results imply that the male adolescent hands grow short and thick in the adolescent period. Fingers continuously grow up as a long and thin shape after adolescent period.

• Journal of Korean society of Dental Hygiene
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• v.13 no.3
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• pp.449-456
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• 2013

Objectives : The objectives of this study were to investigate the handwashing and practice of health science college students and emphasize the importance of handwashing and infection control precaution to the students. Methods : This study was conducted by 586 health science college students through self-reported survey. All data were analyzed using SPSS/PC 13.0 program. Results : 1. Female students washed hands more frequently(7 times per day) than male students(6 times per day). Female students washed hands for 39 seconds in the meanwhile male students washed hands for 28 seconds. 2. Handwashing after using toilet accounted for 79.6% and 72.0% in female and male students, respectively. 3. Most of the handwashing was performed with faucet water (82.1%). The others were tepid water (54.3%), running water (98.1%) and water with soap bar (66.7%). 4. The reason for not practicing handwashing was due to annoyingness (36.3%). Conclusions : Health science college students' tended to wash their hands frequently. However, there existed a gap between the handwashing perception and practice in the previous reports because the observed practice was different from self-estimated perception.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.7
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• pp.568-577
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• 2000

In this paper for an object grasped by a robot hand to work in stiffness control domain we first investigate the number of fingers for successful stiffness modulation in the object operational space. Next we propose a new compliance control method for robot hands which consist of two steps. RIFDS(Resolved Inter-Finger Decoupling Solver) is to decompose the desired compliance characteristic specified in the op-erational space into the compliance characteristic in the fingertip space without inter-finger coupling and RIJDS(Resolved Inter-Joint Decoupling Solver) is to decompose the fingertip space without inter-finger coupling and RIJDS(Resolved inter-Joint Decoupling Solver) is to decompose the compliance characteristic in the finger-tip space into the compliance characteristic given in the joint space without inter-joint coupling. Based on the analysis results the finger structure should be biominetic in the sense that either kniematic redundancy or force redundancy are required to implement the proposed compliance control scheme, Five-bar fingered robot hands are used as an illustrative example to implement the proposed compliance control method. To show the effectiveness of the proposed compliance control method simulations are performed for two-fingered and three-fingered robot hands.

• Journal of Food Hygiene and Safety
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• v.25 no.2
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• pp.133-142
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• 2010

This study was performed to investigate awareness of hand washing, hand washing behavior, and the levels of indicator microorganisms on hands of food handlers who work in the food court and cafeteria of a university campus. The three methods used were questionnaire survey by interview, direct observation in restrooms, and microbiological examination according to the Food Code of Korea. A positive attitude toward hand washing compliance was reported by the responded food handlers; however, improper hand washing and poor hand hygiene of the food handlers were recognized by the unnoticed direct observation. Significant differences were found between the questionnaire survey and the direct observation (p < 0.05) in hand washing compliance after using the toilet, duration of hand washing, use of hand washing agent, washing different parts of the hands, hand-drying method, temperature of water, and method of turning off the water. Samples taken from their hands before work showed higher level of standard plate count, total and fecal coliforms, and Escherichia coli than those taken after washing with water. After washing hands with antiseptic liquid soap, the bacterial populations including Staphylococcus aureus on hands were dramatically reduced. This study indicates that there is a remarkable difference between the food handlers' awareness of hand washing and their hand washing behavior. Poor hand washing compliance and hand hygiene were indicated by the positive results of total and fecal coliforms, E. coli, and S. aureus on hands of some food handlers. The findings of this study suggest that the hand hygiene of the food handlers need to be improved. More training/education on hand washing and hand hygiene of the food handlers should be necessary.