• Journal of the Korean Society for Precision Engineering
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• v.26 no.5
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• pp.142-149
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• 2009

This paper proposes and demonstrates novel flexible contact force sensing devices for 3-dimensional force measurement. To realize the sensor, polyimide and polydimethylsiloxane are used as a substrate, which makes it flexible. Thin-film metal strain gauges, which are incorporated into the polymer, are used for measuring the three-dimensional contact forces. The force sensor characteristics are evaluated against normal and shear load. The fabricated force sensor can measure normal loads up to 4N. The sensor output signals are saturated against load over 4N. Shear loads can be detected by different voltage drops in strain gauges. The device has no fragile structures; therefore, it can be used as a ground reaction force sensor for balance control in humanoid robots. Four force sensors are assembled and placed in the four corners of the robot's sole. By increasing bump dimensions, the force sensor can measure load up to 20N. When loads are exerted on the sole, the ground reaction force can be measured by these four sensors. The measured forces can be used in the balance control of biped locomotion system.

• Biomolecules & Therapeutics
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• v.13 no.3
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• pp.165-173
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• 2005

The main aim of this study was to investigate stress related activities of ginsenosides and their action mechanism. Control group and ginsenoside supplemented groups were exposed to stress while no-stress group was not done. Animals of each group (n=$8\~10$) were orally administerd 100 mg red ginseng extract (R-G), or 10 mg ginsenosides/kg body weight once a day. Animals were given materials for 5 days without stress, and then were given supplements for 5 days with restraint and electroshock stress. Mice were given materials for 5 days for experiments on anti-fatigue effect. After loading final stress, stress-related behavioral changes of experimental animals were examined and plasma corticosterone levels were measured. R-G and ginsenoside $Rb_{1}$ supplementation partially blocked the stress effects on locomotion and elevated plus-maze test in rats and mice. They also partially blocked stress induced behavioral changes such as freezing, smelling, face-washing, rearing behavior in rats. R-G and $Rb_{1}$ decrease adrenal gland size and plasma corticosterone level, which were increased by stress in rats. R-G increased enduring time on the Rota rod, cold water and horizontal wire, but $Rb_{1}$ didn't. Effects of $Rb_{1}$ on plusmaze test were inhibited by administration of flumazenil. These results suggest that $Rb_{1}$ is the main antistress principle in ginseng and it's effect is modulated by GABAnergic nervous system.

• Korean Journal of Applied Biomechanics
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• v.21 no.2
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• pp.215-222
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• 2011

The purpose of this study was to analyze the effects of the use of the lower extremity supporter to ground reaction force(GRF) & EMG in women. Five women participated in the experiment conducted in the study(age: $46.7{\pm}3.5$ yrs, weight: $52.3{\pm}2.2$ kg, lower extremity height: $74.1{\pm}0.9$ cm, knee height: $40.7{\pm}1.4$ cm). The Ground reaction force was measured by AMTI ORG-6 and the Muscle activity of the lower extremity was measured by an 8-channel surface EMG system(Noraxon Myoresearch, USA, 1000Hz). We statistically compared muscle activity and ground reaction force with and without the lower-extremity supporter by one-way repeated ANOVA. The results were as follows. First, the use of the lower extremity supporter affects the ground reaction force along the anterior-posterior axis(Y). Second, the vertical(Z-axis) reaction force on the upper part of the lower extremity supporter increase because of the difference between the interval of vertical movement. Third, the muscle activity of the lateral gastrocnemius and rectus femoris was higher in the upper part of the lower extremity supporter. Further research for example, on a comparative analysis of joint moments, the effects of direct stressor on joints. and the relationship between muscle activity and joint movement, is necessary for a better understanding of the effects of the lower-extremity supporter.

• Korean Journal of Pharmacognosy
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• v.2 no.1
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• pp.23-28
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• 1971

This study was planned to see whether the Panax Ginseng root has any influence upon the emotionality in rats exposed to a novel open-field and induced by a grid shock. Sixty four male albino rats whose body weight ranged from 130 to 180 gm were used. They were divided into four groups, i.e., placebo control group, 5mg/kg Ginseng ext. group, 10mg/kg Ginseng ext. group, and 20mg/kg Ginseng ext. group. Sixteen rats were subjected in each group. Open-field activity was measured in a $2.20m\;{\times}\;2.20m$ open-field that was divided into 15cm squares. Four novel objects and food pellets were put with an equal distance in the open-field. Locomotion was recorded by entering the number of squares traversed for 4 min. and behaviors which were shown at the 10-sec. period were checked by a modified Jarrad and Bunnel's observation procedure. Sensitivity to the grid shock was measured in a compartment of shuttle box. 10, 20, 30, 40, 50, 60 and 70 volt ac. 2 sec., electric shock were delivered in each subject by the grid to animal's feet. Flinch, vocalization and jumping responses were rated in each shock level. The results obtained were as follows: 1.) 5mg/kg and 10mg/kg Ginseng ext. groups were tended to increase the ambulation and exploration compared with placebo control. 2.) All Ginseng extract groups were defecated significantly less often than placebo control in the open-field and shock situation. 3.) Thresholds to the electric shock were tended to elevate in all Ginseng groups. 4.) These results suggest that Ginseng extract has a stimulant action in open-field and a tranqulizing action in feared situation.

• Journal of Convergence for Information Technology
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• v.10 no.4
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• pp.1-10
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• 2020

The performance of the personalized product recommendation system for offline shopping malls is poor compared with the one using online environment information since it is difficult to obtain visitors' characteristic information. In this paper, a mobile robot platform is suggested capable of recommending personalized advertisement using customers' sex and age information provided by Face API of MS Azure Cloud service. The performance of the developed robot is verified through locomotion experiments, and the performance of API used for our robot is tested using sampled images from open Asian FAce Dataset (AFAD). The developed robot could be effective in marketing by providing personalized advertisements at offline shopping malls.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.2
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• pp.108-115
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• 2009

Thanks to the development of computer graphics, Animation can be easily accessed through movies or games. The users can meet various contents and are asking for high quality animations that resembles reality to a near perfection. The research is proceeded to observe the fish shapes and swimming movements through cyber aquariums, fish ecology museums and fish encyclopedias. The core of expressing undersea scenery is the natural and dynamic movements of the fish. In this thesis in order to achieve the natural shape of fish swimming, it is necessary to design a fish growth process system based on environmental factors and apply different standard points depending on the various swimming types of fish species to express the fish as near reality as possible. And by calculating the different swimming velocities of different standard points, a natural swimming shape will be achieved.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.9
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• pp.926-934
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• 2006

This paper proposes intelligent control of a virtual walking machine that can generate infinite floor for various surfaces and can provide proprioceptive feedback of walking to a user. This machine allows users to participate in a life-like walking experience in virtual environments with various terrains. The controller of the machine is implemented hierarchically, at low-level for robust actuator control, at mid-level fur platform control to compensate the external forces by foot contact, and at high-level control for generating walking trajectory. The high level controller is suggested to generate continuous walking on an infinite floor for various terrains. For the high level control, each independent platform follows a man foot during the swing phase, while the other platform moves back during single stance phase. During double limb support, two platforms manipulate neutral positions to compensate the offset errors generated by velocity changes. This control can, therefore, satisfy natural walking conditions in any direction. Transition phase between the swing and the stance phases is detected by using simple switch sensor system, while human foot motions are sensed by careful calibration with a magnetic motion tracker attached to the shoe. Experimental results of walking simulations at level ground, slope, and stairs, show that with the proposed machine, a general person can walk naturally on various terrains with safety and without any considerable disturbances. This interface can be applied to various areas such as VR navigations, rehabilitation, and gait analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.344-349
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• 2017

Wall-climbing robots have been developed for various purposes, such as cleaning skyscraper windows, maintaining large structures, and welding vessels. Conventional wall-climbing robots use movement systems based on wheels or legs. However, wheeled robots suffer from slipping effects, while legged systems require many actuators and control systems for the complex linkage structure, which also increases the weight of the robot. To overcome these disadvantages, we propose a new wall-climbing robot that walks based on gorilla locomotion. The proposed robot consists of a DC drive motor, a vacuum pump for adsorption, and a micro controller for controlling the system. The performance of the robot was experimentally verified on vertical and horizontal flat surfaces. The robot could be used for various functions in industrial sites or disaster areas.

• Journal of Preventive Medicine and Public Health
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• v.55 no.4
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• pp.334-341
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• 2022

Objectives: This study was conducted to develop the Mobility to Participation Assessment Scale for Stroke (MPASS) and assess its content validity, internal consistency, inter-rater and intra-rater reliability, and convergent validity in people with stroke living in the community. Methods: The MPASS was developed using published data on mobility-related activity and participation timing in elderly individuals, and then reviewed by community physical therapists. Content validity was established by reaching a consensus of experienced physical therapists in a focus group. The MPASS was scored for 32 participants with stroke (mean age 61.75±4.92 years) by 3 individual testers. Reliability was examined using the intraclass correlation coefficient (ICC), internal consistency using the Cronbach alpha coefficient (α), and convergent validity using the Pearson correlation coefficient (r) to compare the MPASS to the Modified Rivermead Mobility Index as a referent test of mobility. Results: The MPASS consists of 8 items, and its scoring system provides information on the ability of people with stroke to reach a movement level enabling them to live in society, including interactions with other people and safe living in the community. The interrater and intra-rater reliability were excellent (ICC, 0.948; 95% confidence interval [CI], 0.893 to 0.982 and ICC, 0.967; 95% CI, 0.933 to 0.989, respectively). Internal consistency was good (α=0.877). The convergent validity was moderate (r=0.646; p<0.001). Conclusions: The newly developed MPASS showed acceptable construct validity and high reliability. The MPASS is suitable for use in people with stroke, especially those who have been discharged and live in the community with the ability to initiate sitting.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.10
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• pp.1512-1518
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• 2015

This experiment was conducted to assess the welfare and productivity of gestating gilts in groups with the electronic sow feeding (ESF) system compared to conventional stalls. A total of 83 gilts ($Yorkshire{\times}Landrace$) were housed into individual stalls to be artificially inseminated. Gilts confirmed pregnant were introduced to their treatment, conventional stalls (ST) or groups with the ESF system. All gilts were taken to the farrowing crates one week prior to their expected farrowing date. In the gestation period, there were no significant differences between gilts allocated to ST and ESF on growth performance. However, backfat thickness gain (p = 0.08) and body condition score (BCS) at 110 days of gestation (p = 0.10) tended to be higher in ESF gilts than ST. Likewise, gilts housed in group showed significantly higher estimated body muscle contents at 110 days of gestation (p = 0.02) and body muscle change during gestation (p = 0.01). There was a trend for a shorter parturition time in ESF gilts (p = 0.07). In the lactation period, group housed gilts showed a tendency to increased BCS changes (p = 0.06). Reproductive performance did not differ with the exception of piglet mortality (ST = 0.2 no. of piglets vs ESF = 0.4 no. of piglets; p = 0.01). In blood profiles, ST gilts showed a higher cortisol level at 110 days of gestation (p = 0.01). Weaning to estrus interval was shorter in gilts housed in ESF than ST (p = 0.01). In locomotory behaviors, ESF gilts recorded a tendency to elevate locomotion score at 36, 70, and 110 days of gestation (p = 0.07, p = 0.06, and p = 0.06, respectively). Similarly, ESF gilts showed significantly higher incidence of scratches at 36, 70, and 110 days of gestation (p = 0.01). Moreover, farrowing rates were higher in stall treatment (97.6%) compare to group housing treatment (95.2%). In conclusion, while group housed gilts with ESF system positively affected welfare status in combination with less physiologically stressful environments and activity, it negatively effects piglet mortality, farrowing rates and injuries of gilts.