• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.1 s.256
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• pp.36-42
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• 2007

This paper presents mechanical design, fabrication and test of a biomimetic fish robot actuated by a unimorph piezoceramic actuator, LIPCA(Lightweight Piezo-Composite curved Actuator.) We have designed a linkage mechanism that can convert bending motion of the LIPCA into the caudal fin movement. This linkage system consists of a rack-pinion system and four-bar linkage. Four types of artificial caudal fins that resemble caudal fin shapes of ostraciiform subcarangiform, carangiform, and thunniform fish, respectively, are attached to the posterior part of the robotic fish. The swimming test under 300 $V_{pp}$ input with 0.6 Hz to 1.2 Hz frequency was conducted to investigate effect of tail beat frequency and shape of caudal fin on the swimming speed of the robotic fish. At the frequency of 0.9 Hz, the maximum swimming speeds of 1.632 cm/s, 1.776 cm/s, 1.612 cm/s and 1.51 cm/s were reached for fish robots with ostraciiform, subcarangiform carangiform and thunniform caudal fins, respectively. The Strouhal number, which means the ratio between unsteady force and inertia force, or a measure of thrust efficiency, was calculated in order to examine thrust performance of the present biomimetic fish robot. The calculated Strouhal numbers show that the present robotic fish does not fall into the performance range of a fast swimming robot.

• Journal of Pharmacopuncture
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• v.22 no.2
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• pp.68-74
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• 2019

Objectives: Cultivated wild ginseng (cWG), called SanYangSanSam, has been used clinically in patients with chronic fatigue in Korea. Little is known about effects of the ginseng distilled (volatile) components produced during evaporizaiton. Recently, we first identified one major component from cWG distilled extract, panaxydol, by using mass spectrometry. However, functional properties of cWG distilled extract and panaxydol remains elusive. Therefore, the present study evaluated the effect of cWG distilled extract or panaxydol on exercise-induced fatigue in rats. Methods: Fatigue was induced by forced swimming and the immobility time was analyzed in male Sprague-Dawley rats. The animals received intraperitoneally either vehicle, cWG distilled extract, or panaxydol 10 min prior to beginning of the forced swimming test (FST) once daily for 5 days. After the FST on day 5, we also analyzed fatigue-related biochemical levels including blood urea nitrogen (BUN), lactate acid (LAC), and lactate dehydrogenase (LDH) in serum and levels of glycogen in liver and soleus muscle. Results: The forced swimming time in cWG distilled extract (0.6 mL/kg)-treated group was significantly longer than that of control group on day 4 and 5. Panaxydol (0.1 and 0.25 mg/kg)-treated groups showed significantly enhanced performance in the forced swimming, compared to control. In addition, a significant decrease in serum LDH level was found in panaxydol-treated group, while there were no alternations in levels of serum BUN and LAC and glycogen in liver or soleus muscle. Conclusion: The present study demonstrated cWG distilled extract and its active component panaxydol have a function of anti-fatigue.

• Smart Structures and Systems
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• v.10 no.6
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• pp.501-515
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• 2012

We design and test a shape memory alloy (SMA)-based actuation system that can be used to propel a fish robot. The actuator in the system is composed of a 0.1 mm diameter SMA wire, a 0.5 mm-thick glass/epoxy composite strip, and a fixture frame. The SMA wire is installed in a pre-bent composite strip that provides initial tension to the SMA wire. The actuator can produce a blocking force of about 200 gram force (gf) and displacement of 3.5 mm at the center of the glass/epoxy strip for an 8 V application. The bending motion of the actuator is converted into the tail-beat motion of a fish robot through a linkage system. The fish robot is evaluated by measuring the tail-beat angle, swimming speed, and thrust produced by the tail-beat motion. The tail-beat angle is about $20^{\circ}$, the maximum swimming speed is about 1.6 cm/s, and the measured average thrust is about 0.4 gf when the fish robot is operated at 0.9 Hz.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.5
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• pp.219-224
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• 2015

In this paper, the designed fish robots DOMI ver1.0 is researched and development for aquarium underwater robot. The presented fish robot consists of the head, 1'st stage body, 2nd stage body and tail, which is connected two point driving joints. The model of the robot fish is analysis to maximize the momentum of the robot fish and the body of the robot is designed through the analysis of the biological fish swimming. Also, Lighthill was applied to the kinematics analysis of robot fish swimming algorithms, we are applied to the approximate method of the streamer model that utilizes techniques mimic the biological fish. The swimming robot has two operating mode such as manual and autonomous operation modes. In manual mode the fish robot is operated to using the RF transceiver, and in autonomous mode the robot is controlled by microprocessor board that is consist PSD sensor for the object recognition and avoidance. In order to the submerged and emerged, the robot has the bladder device in a head portion. The robot gravity center weight is transferred to a one-axis sliding and it is possible to the submerged and emerged of DOMI robot by the breath unit. It was verified by the performance test of this design robot DOMI ver1.0. It was confirmed that excellent performance, such as driving force, durability and water resistance through the underwater field test.

• Science of Emotion and Sensibility
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• v.10 no.2
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• pp.243-252
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• 2007

Anti-depressant and anti-anxiety effects of Saccharomyces cerevisiae extract and its hydrolyzed fraction. The purpose of the present study was to examine the effect of Saccharomyces cerevisiae extract (SCE) and its hydrolyzed fraction (SCE-40) on depression and anxiety-related behaviors in mice. Actions of SCE and SCE-40 on serotonin, norepinephrine and GABAergic systems in the rat cerebral cortex membranes were also examined. SCE and SCE-40 significantly reduced the immobility time in the forced swimming and tail suspension test in mice. Duration time of the open arms in the elevated plus maze test was significantly increased in the SCE and SCE-40-treated groups, compared with the saline-treated control group. SCE and its fraction SCE-40 significantly inhibited serotonin and norepinephrine transporter and GABA receptor binding, compared to the saline-treated group. In addition, serotonin and norepinephrine reuptake were significantly suppressed by SCE and SCE-40. These results demonstrate that SCE and SCE-40 produce anti-depressant and anti-anxiety effects through enhancing central serotonin, norepinephrine and GABAergic transmissions. These results suggest that SCE and SCE-40 as functional food might prove to be an effective antidepressant and anti-anxiety agent.