• Journal of Advanced Marine Engineering and Technology
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• v.23 no.6
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• pp.778-784
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• 1999

In this study both the experimental and the analytic approach to find load characteristics on the cam-valve mechanism for matrine diesel engine were demonstrated. The experiment was per-formed with a test rig consisted of real engine components for cam-valve mechanism of overhead valve type. The 9-degree of freedom lumped mass model was developed to simulate cam-valve motion throughly. Behavior of the load acting on the cam-valve mechanism was estimated for the various cam speed. The load variation was getting deeper with the higher cam speed and the jumping of the follower was shown both in the experiment and in the simulation.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.2 s.191
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• pp.64-72
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• 2007

Many human-body motions such as walking, running, jumping, etc. require a significant amount of power. To achieve a high power-to-weight ratio of the humanoid robot system, this paper proposes a new design of the bio-mimetic leg mechanism resembling musculoskeletal system of the human body. The hip joints of the system considered here are powered by 5 human-like bi-and mono-articular muscles, and the joints of knee and ankle are redundantly actuated by both bi-articular muscles and joint actuators. The kinematics for the leg mechanism is derived and a kinematic index to measure force transmission ratio is introduced. It is demonstrated through simulation that incorporation of redundant muscles into the leg mechanism enhances the power of the mechanism approximately 2 times of the minimum actuation.

• Korean Journal of Applied Biomechanics
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• v.21 no.2
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• pp.197-205
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• 2011

Various jumping and landing motions are shown during sports event. But most previous studies have not considered landing height and distance simultaneously. The purpose of this study was to identify the effects of landing height and distance on knee injury mechanism. Fourteen male(age: $28.86{\pm}1.99$ yrs, height: $177.00{\pm}4.69$ cm, weight: $76.50{\pm}6.41$ kg) participated in this study. The subjects attempted drop landing task onto the ground from 30 cm to 45 cm heights and to 20 cm to 40 cm distances. The results were as follows. First, higher drop landing height and longer distance showed greater degree of maximal knee flexion and valgus. Second, higher drop landing height and longer distance showed greater maximal knee extension moment and varus moment. Third, higher drop landing height and longer distance showed larger maximal knee absorption power. Lastly, higher drop landing height showed increased Peak GRF. Landing height was more related to the cause of injury, which was indicated by increased maximal knee extension moment, peak GRF and maximal knee absorption power. Landing distance was also associated with increased knee valgus moment and absorption power during landing. These results suggest that landing height and distance may be the cause of injury.

• Journal of Ginseng Research
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• v.32 no.1
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• pp.1-7
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• 2008

Ginseng saponin has been shown to inhibit the development of dependence on morphine, cocaine, methamphetamine, but the antinarcotics effects of ginseng on nalbuphine remains still largely unknown. Ginseng administration attenuated the naloxone-induced jumping behavior on nalbuphine dependent mice. The development of morphine dependence was mediated through ${\mu}-opioid$ receptor, however, development of nalbuphine dependence was mediated through ${\kappa}-opioid$ receptor. However, it was found that the efficacy of analgesic antagonism of GTS was mediated through the serotonergic mechanism, not mediated through the opioid receptor. In addition, ginseng administration modulated cellular signal transduction in the brain. The increased NMDA receptor subunit (NR1, pNR1), phosphate extracellular signal regulated protein kinase (pERK), phosphate cAMP response element binding protein (pCREB) expression by nalbuphine was decreased by the administration of ginseng powder in cortex, hippocampus, striatum of rat brain. These results suggest that ginseng could be one of the targets of antinarcotic therapies to reduce the development of tolerance and dependence on nalbuphine as well as morphine.

• Korean Journal of Computational Design and Engineering
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• v.13 no.2
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• pp.77-88
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• 2008

Nowadays personal users create a variety of multi-media contents and share them with others through various devices over the Internet since the concept of user created content (UCC) has been widely accepted as a new paradigm in today's multi-media market, which has broken the boundary of contents providers and consumers. This paradigm shift has also introduced a new business model that makes it possible for them to create their own multi-media contents for commercial purpose. This paper proposes a tangible virtual studio using augmented reality to author multi-media contents easily and intuitively for personal broadcasting and personal content generation. It provides a set of tangible interfaces and devices such as visual markers, cameras, movable and rotatable arms carrying cameras, and miniaturized set. They can offer an easy-to-use interface in an immersive environment and an easy switching mechanism between tangible environment and virtual environment. This paper also discusses how to remove inconsistency between real objects and virtual objects during the AR-enabled visualization with a context-adaptable tracking method. The context-adaptable tracking method not only adjusts the locations of invisible markers by interpolating the locations of existing reference markers, but also removes a jumping effect of movable virtual objects when their references are changed from one marker to another.

• YAKHAK HOEJI
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• v.56 no.4
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• pp.236-239
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• 2012

The aim of present study was to investigate the possible influence and the related mechanism of Cinnamomum cassia derived-cinnamaldehyde on the inflammation or nociception. Cinnamomum cassia was referred to be treated for common cold or dyspepsia in the traditional medicine. However, there are no reports on the antinociceptive or anti-inflammatory properties of cinnamaldehyde, the primary ingredient of Cinnamomum cassia. We hypothesized that cinnamaldehyde would play a role in the modulation of inflammation or nociception evoked by carrageenan, acetic acid or heat. Male Institute of Cancer Research mice were used and the size of edema, frequency of writhing and latency of abnormal behaviors such as licking, flicking, shaking or jumping were measured and recorded. The present study was carried out to evaluate the antiinflammatory and antinociceptive effects of cinnamaldehyde. The administration of cinnamaldehyde (30 and 100 mg/kg) inhibited carrageenan-induced paw edema only at the final phase, suggesting the blockade of synthesis or release of prostaglandins. It also reduced the frequency of the acetic acid-induced writhing reflex in mice. In addition, the administration of cinnamaldehyde prolonged the latency for extraordinary reaction at the hot plate in mice. In conclusion, cinnamaldehyde has anti-inflammatory and analgesic properties and is a potential therapeutic for inflammation and nociception.

• Journal of Magnetics
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• v.10 no.4
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• pp.157-162
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• 2005

We report the magnetic-field dependence of the irreversible magnetization of binary superconductor $MgB_2$. For the temperature region of $T\;<\;0.9T_c$, the contribution of the bulk pinning to the magnetization overwhelms that of the surface pinning. This was evident from the fact that the magnetization curves, M(H), were well described by the critical-state model without considering the reversible magnetization and the surface pinning effect. It was also found that the M(H) curves at various temperatures scaled when the field and the magnetization were normalized by the characteristic caling factors H$\ast$(T) and M$\ast$(T), respectively. This feature suggests that the pinning mechanism determining the hysteresis in M(H) is unique below $T\;=\;T_c$.

• Biomolecules & Therapeutics
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• v.21 no.4
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• pp.307-312
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• 2013

Quetiapine is an atypical or second-generation antipsychotic agent and has been a subject of a series of case report and suggested to have the potential for misuse or abuse. However, it is not a controlled substance and is not generally considered addictive. In this study, we examined quetiapine's dependence potential and abuse liability through animal behavioral tests using rodents to study the mechanism of quetiapine. Molecular biology techniques were also used to find out the action mechanisms of the drug. In the animal behavioral tests, quetiapine did not show any positive effect on the experimental animals in the climbing, jumping, and conditioned place preference tests. However, in the head twitch and self-administration tests, the experimental animals showed significant positive responses. In addition, the action mechanism of quetiapine was found being related to dopamine and serotonin release. These results demonstrate that quetiapine affects the neurological systems related to abuse liability and has the potential to lead psychological dependence, as well.

• Korean Journal of Materials Research
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• v.26 no.12
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• pp.721-725
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• 2016

This work focuses on the electrical conduction mechanism in a lead free ($Na_{0.5}K_{0.5}NbO_3$ ; NKN) ceramics system with $LiNbO_3$ content of approximately critical concentration $x{\geq}0.2$. Lead free $(1-x)(Na_{0.5}K_{0.5})NbO_3-x(LiNbO_3)$, $NKN-LN_x$ (x = 0.1, 0.2) ceramics were synthesized by solid-state reaction method. Crystal structures are confirmed by X-ray diffraction. The electric-mechanical bond coefficient $k_p$ decreases and the phase transition temperature $T_c$ increases with increasing x content, as determined by dielectric and piezoelectric measurements. The value of the real dielectric constants ${\varepsilon}^{\prime}$ and $k_BT{\varepsilon}^{\prime\prime}$ showed anomalies around $T_c$ ($462^{\circ}C$ in the NKN-LN0.1 and $500^{\circ}C$ in the NKN-LN0.2). For the ionic conduction of mobile ions, the activation energies are obtained as $E_I=1.76eV$ (NKN-LN0.1) and $E_I=1.55eV$ (NKN-LN0.2), above $T_c$, and $E_{II}=0.78$ (NKNL-N0.1) and $E_{II}=0.81$ (NKN-LN0.2) below $T_c$. It is believed that the conduction mechanisms of NKN-LNx ceramics are related to ionic hopping conduction, which may arise mainly due to the jumping of $Li^+$ ions.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.1
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• pp.1-9
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• 2013

This study examined the effects of the occlusal stability and a partial coverage mouthguard on physical fitness and motor capacity to determine the importance of the occlusal stability as a possible action mechanism of mouthguards on physical performance. Twenty physical education students were included for measurements of their handgrip strength, back strength, whole body reaction time, flexibility, sidestep test, stork stand test and jumping test according to the following 5 different occlusal conditions: mouth closed position without a mouthguard, with a full coverage mouthguard, with a right partial coverage mouthguard, with a left partial coverage mouthguard and with anterior partial mouthguard. The results revealed no significant difference in any of the measured physical factors between the occlusal conditions with and without a full-coverage mouthguard. On the other hand, a significant difference was observed in whole body reaction between the occlusal conditions with and without the partial coverage mouthguards. Therefore, isokinetic muscle tests on both knee joints and the Wingate anaerobic power test should be performed under the following five occlusal conditions: with or without full-coverage maxillary custom-made mouthguard, with a unilateral right or left partial-coverage maxillary mouthguard and with an anterior partial-coverage maxillary mouthguard. These results suggest that the partial coverage mouthguard had a short-term beneficial effect on agility rather than full coverage mouthguard.