• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.947-948
• /
• 2006

This paper proposes a robust posture stabilization control method for wheeled mobile robots. To solve the robust posture stabilization, we introduce reference generation mode, reference tracking mode, and reference regulation mode. In reference generation mode, a kinematic time-invariant controller is used to generate the reference trajectory which starts from the initial posture of the actual robot to the desired posture. In reference tracking mode, a sliding mode position controller is employed in such a way that the actual robot can follow the reference trajectory in the desired forward or backward moving direction, even in the presence of the disturbances in the dynamics. In reference regulation mode, a sliding mode heading direction controller is used such that the actual robot can maintain the desired posture against the disturbances. In this way, robust posture stabilization can be achieved at almost all global regions.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.10
• /
• pp.180-189
• /
• 2014

For a autonomous parking of unmanned car, this paper proposes a posture regulation algorithm of a car-like mobile robot, which is supported by a docking formation and a feedback linearization control law. Unlike the previous researches based on a path-planning and optimization algorithms, the autonomous car implemented the proposed autonomous parking algorithm can be parked without much computational burden and a high performance processor. Stability of the proposed docking formation and feedback linearization control law are analyzed and performance of the proposed algorithm is shown by implementing to the simulations with six scenarios and an actual car in the experiment place.

• Journal of the Korean Society for Precision Engineering
• /
• v.24 no.5
• /
• pp.110-117
• /
• 2007

According to the pedestrian protection regulations of Europe and Japan, the head injury must not exceed a limitation in the defined test condition for the protection of pedestrians from a vehicle crash. However, it is difficult to evaluate the performance of protection because each regulation has different test conditions such as dummy, impact speed and so on. This circumstance needs the development of a model that describes the anthropometry of the crash victim with a sufficient accuracy. We constructed scaled pedestrian dummies using MADYSCALE. Simulations were performed for various crash speeds and pedestrian postures. The scaled Korean dummies and HybridIII dummies were used to compare the pedestrian dynamic behaviors and head injury criteria during the collision. The HIC values of scaled korean dummies were found to be higher than those of Hybrid III dummies. The impact for gait posture was less than that for standing.

• Journal of the Korean Society of Safety
• /
• v.18 no.3
• /
• pp.149-153
• /
• 2003

Recently, work-related musculoskeletal disorders(WMSDs) are one of major issues in occupational safety and health in Korea. Main risk factors of WMSDs include manual handling of heavy weight loads, awkward posture, repetitive tasks, Prolonged static muscle contraction, and so on. The number of injured workers has rapidly increased and the related regulation was amended to improve the work conditions and environments. And demands for workers' compensation and improvement of work conditions and environment to prevent WMSDs have increasingly been raised. This study focused on managerial system to prevent WMSDs. Literal survey and questionnaire survey were accomplished to propose a management system in Korea for preventing WMSDs.

• Korean Journal of Applied Biomechanics
• /
• v.26 no.3
• /
• pp.243-248
• /
• 2016

Objective: The aim of this study was to determine the kinematical characteristics of somersault with twist in the Lou Yun and Akopian motions and to provide useful information to gymnastic athletes in men's vault. Method: The study subjects were 12 male adult top athletes. After 12 trials (7 Lou Yun and 5 Akopian trials) filmed by using two digital high-speed camcorders set at 90 frames/sec, kinematical data were collected through the direct linear transformation (DLT) method. The mean differences in biomechanical variables were compared during the second flight upward phase. The kinematic characteristics of somersault with twist in the Lou Yun and Akopian motions were identified. Results: In Lou Yun motion, the vertical release velocity through horse breaking was not difficult to obtain, so the athletes had enough time to prepare for the twist. Therefore, the Lou Yun motion has an advantage to make a cat twist in the pike posture. In the Akopian motion, obtaining the horizontal velocity through horse pushing was so easy that the Akopian athletes attained a large angular impulse and angular momentum. Therefore, the Akopian motion has an advantage to making a tilt twist in the body tilting posture. Conclusion: This study suggests that gymnastic athletes should control their body segment movements in order to increase the twisting angular velocity of the whole body, which requires regulation of the longitudinal moment of inertia of the body. Moreover, athletes should prepare for the shoulder and hip twists early in order to make the landing position in advance.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.22 no.7
• /
• pp.963-968
• /
• 1998

A study was conducted to investigate the effect of cooling hands of feet on human thermoregulation in the cold. Eight young (22$\pm$1 yr) and eight aged (69$\pm$4 yr) men volun-teered as subjects They stayed at 1$0^{\circ}C$ in the supine posture during the experiment which included hands or feet exposure to the air for 20 minutes. Hand Exposure (HE) and Foot Exposure (FE) were conducted in radomized order and the baseline was kept before HE and FE. Core temperatures, limb skin temperatures adn thermal sensations were measured. Obtained data were analyze using t-test and correlation. Rectal and esophageal tem-peratures increased in the young (YG) and in aged (AG). Change rate of esophageal temperature (Tes) was maintained higher during FE than HE while rectal temperature showed no differences between YG and AG, and between HE and FE. Hand and foot skintemperature in YG and AG decreased similarly during HE and Fe. Forearm skin temperature during HE decreased while leg skin temperature during FE showed no change HE and Fe. It was concluded that the lower cooling. Furthermore, the increase of Tes was greater in young men than aged men. It is also suggested that the wearing behavior can be differently modified between young and aged men.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.43 no.3
• /
• pp.405-415
• /
• 2019

This study examined the physiological and psychological effects of wearing a winter cap at rest in a cold environment. Seven older males participated in two separate trials: wearing a winter cap (CAP) and non-wearing a winter cap (CON). The experiment was conducted for 60 min in a climatic chamber (air temperature $7.8{\pm}0.3^{\circ}C$ with $43{\pm}2%RH$) with sedentary posture. Microclimate temperature at the vertex of the head was $6.88^{\circ}C$ higher in CAP compared to CON (p<.01). Microclimate humidity at the vertex was lower in CAP than in CON only during the last 5 min (p<.01). Skin temperature at the forehead in CAP was higher than in CON (p<.01). During the last 5 min, rectal temperature was higher in CAP than that in CON (p<.05). Unlike CAP, the heart rate in CON during the last 5 min decreased significantly compared to the initial 5 min (p<.05). Subjects also felt less cold on the head/face in CAP than that in CON (p<.01). The results indicate that wearing a cap for elderly males positively affected body temperature regulation and cardiovascular response in cold environments. The importance of wearing warm hats for elderly males in winter should be emphasized.

• Research in Community and Public Health Nursing
• /
• v.9 no.1
• /
• pp.40-63
• /
• 1998

A long life is the desire of many people. The purpose of this study was to describe long life factors for people aged one hundred and above on Chju island. The research was conducted using a phenomenological method to add understanding to this subject. The field work for this study was done from July, 1997 to February, 1998 on Cheju island. The sample consisted of 10 persons of one hundred or above and 12 families. They were audio-recorded and analyzed using Colaizzi's (1978) method. The results of the present study shows the following: The thoughts of the persons one hundred and above showed ten important concepts; 'dietary regimen', 'mental regimen', 'sleep regimen', 'residence regimen', 'health regimen', 'labor regimen', 'exercise regimen', 'being born', 'filial piety and posterity', 'attachment to life'. Concerning 'Dietary Regimen': Dietary regulation, Preferential food intake, Living on vegetables, Light eating, and concern for longevity in food intake were important. Concerning 'Mental Regimen' : Harmony, Clearheadedness, Mildness, Abstinence, Generosity, Relaxation, Gaiety, Inspiration and Strength were important. Concerning 'Sleep Regimen'; Enough sleeping hours, Sound sleep, Curved sleeping posture, and Comfortable bedding were important. Concerning 'Residence Regimen' ; Clean dwelling, Pleasant surroundings, Thatched house life, Living in the village with good-hearted people, and Regular life were important. Concerning 'Health Regimen'; Temperance of drug, use Proper temperature, Proper humidity, and a Clean body were important. Concerning 'Labor Regimen'; Agricultural labor, Diligence, and Domestic labor were important. Concerning Exercise Regimen': Proper exercise, and Sunbathing were important. Concerning 'Being Born' ; Strong physical constitution, Longevity lineage, and Destiny were important. Concerning 'Filial Piety and Posterity' : Showing respect to a long-lived elder and Reducing anxiety were important. Concerning 'Attachment to Life' ; The desire to live long was important. The following conclusion was made from the above results. Human beings cannot avoid death, but the span of life can be prolonged to the maximum span of human life by wisdom, health care, and proper environmental conditions. As a result, a health regimen must be imposed for longevity such as controling food intake, having positive thoughts, being relaxed, sleeping enough, clean dwelling, taking care of oneself which can improve immunity and resistance to decrease, as well as proper labor and exercise. In addition, when filial piety is served, the desire of longevity and retaining one's youthfulness for a long time can be achieved. These should be done to live long and lead a qualitative life. By the results of this research, the following is suggesed for nursing. To satisfy the basic nursing principle that nursing must be practiced to help people live long, education must be spread to people who are nursed and their family so that they can lead a healthy life. And in nursing elders, nurses must recognize that elders have a strong desire for life, even though they may have negative thoughts about life at times. Therefore nurses have to respect the elders' value of life, and help them improve their self-esteem and self -fulfilment.

• Journal of Korean Home Economics Education Association
• /
• v.10 no.2
• /
• pp.29-42
• /
• 1998

The purpose of this study was to identify the contents that students want to learn the most on Home-Economics. Participants were 710 middle school students(359 boys and 351 girls) from 9 schools located in 4 cities and 5 counties in CholaBukDo. The results are as follows: 1. Of 32 contents on Family life, boys were interested in 'the puberty', 'pregnancy and the ethics on sex', 'social needs', 'the importance of family relationship', and 'adolescents' physical development'. On the other hand, girls were more intered in 'pregnancy' and 'the ethics on sex', 'the puberty', 'development of career consciousness' and 'career preparation', 'the adolescents' physiolosical and physical development', and 'the importance of family relationship'. 2. Of 37 contents of Managing home resource and Consumer life subarea, boys showed their interests on 'environmental problems', 'environmental conservation', 'environmental pollution', 'management of time and work', 'knowledge', 'management of their abilities'. And girls were more interested in 'environmental conservation', 'environmental pollution', 'environmental problems', 'adolescents life', and 'management of time and work'. 3. Of 49 contents on Dietary life, boys were more interested in 'puberty and the development', 'importance of nutriment', 'nutrition and health' and 'smoking and the health'. However, girls were more interested in 'smoking and health', 'puberty and the development', 'the importance of nutriment', 'nutrition and health', 'a realistic plan to reduce the food-based environmental pollution'. 4. Of 40 contents on Clothing life subarea, while boys were interested in 'the suitable cloths on oneself', 'clothing design', 'regulation of temparature', physical protection' 'merchandising for ready-made clothing'. On the other hand, girls were mostly interested in 'the suitable cloths on oneself', and next 'the clothing design', 'merchandising for ready-made clothes','physical protection', and 'the appropriate posture and physical adornment'. 5. Of 18 contents on Residence life subarea, teachers emphasized the importance of ventilation for adjusting the room environment and students were more interested in the effective use of the residing space. In general, those middle school students in Cheolabukdo showed the biggest interest on 'Clothing life', 'Residence life' the second, 'Eating life' the third, 'Human development and Family relationship' the fourth, and Management of family resource and Consuming life' was their fifth interest. Such result was consistent with Ⅱ-Rok Park's previous research(1997). Since the participants for this study were sampled form 9 schools located in CheolaBukDo, it is not suitable to apply the results nationwide. The restricted sampling must be considered and further studies are needed to make comparisons among areas.

• Convergence Security Journal
• /
• v.22 no.4
• /
• pp.3-9
• /
• 2022

Recently, as the environment of the 4th industrial revolution has arrived, the opening, sharing and convergence of data are actively being achieved in any organization. However, the opening and sharing of data inevitably leads to security vulnerability and there is ambivalence that is a threat that can affect the existence of an organization operated in the 4th industrial revolution environment. Especially security issues in the organization of the military can be a threat to the state, not the military itself, so it is always necessary to maintain a high level of security discipline. In this paper, 14 variables were selected through structural equation model applying theory of planned behavior, deterrence and protection motivation to find out the security level development measures by extracting factors that can affect security level. As a result, the theory of planned behavior that the security knowledge embodied through the usual security regulation education and evaluation affects the behavior was adopted, and the theory of deterrence and protection motivation showed the significance of the rejection level. In addition, it was confirmed that the variables that have the greatest impact on the military security level through the measured values of the three-year security audit were commanders and mental security. In conclusion, in order to improve the security level, it is suggested that security education, definite reward and punishment, and security system upgrading should be firmly established and mental security posture should be secured.