• Proceedings of the Society of Korea Industrial and System Engineering Conference
• /
• 2002.05a
• /
• pp.445-454
• /
• 2002

This article explains the theory of multiple mode/physical coordinate synthesis method in order to analyze the dynamic characteristics for an huge marine engine. The theory leads to make a simulation code. The natural frequencies obtained from the simulation code is compared to those from a commercial analysis software, ANSYS. The simulation code is well reviewed.

• Proceedings of the Optical Society of Korea Conference
• /
• 2006.02a
• /
• pp.179-180
• /
• 2006

• Physical Therapy Rehabilitation Science
• /
• v.13 no.2
• /
• pp.205-212
• /
• 2024

Objective: The purpose of this study is to confirm the exercise effect when combining wearable exercise assist robot, Bot fit's resist mode (Samsung Electronics) and stair climbing. Design: Cross-section study Methods: Targeting 53 adults and seniors, foot pressure and muscle activity were measured when climbing 3-story stairs using foot pressure measurement equipment (W-insole Science System) and surface muscle activity measurement equipment (sEMG; FreeEMG, BTS Bioengineering, Italy) using Bot Fit's resist mode. All subjects were measured without wearing Bot Fit, and the data between the two conditions were compared and analyzed. Results: The front area(p<0.01) and middle area(p<0.05) foot pressures of adults significantly increased when wearing the Bot fit. Frontal area foot pressure significantly increased in elderly people with knee arthritis and obesity(p<0.05). The gastrocnemius activity in all subjects significantly decreased after wearing Bot Fit(p<0.01). In elderly people with knee arthritis, the muscle activity of the rectus femoris was significantly reduced(p<0.05)., and in obese elderly people, the muscle activity of the gastrocnemius muscle was significantly reduced(p<0.05). Conclusions: Based on the results of this study, it is possible to induce correct stair climbing posture when climbing stairs using Bot fit resistance mode. In particular, it is expected to be an effective exercise for strengthening muscle endurance by increasing the activity of the rectus femoris muscle.

• Korean Chemical Engineering Research
• /
• v.57 no.2
• /
• pp.289-300
• /
• 2019

We have conducted a preliminary numerical analysis to understand the effects of double-diffusive convection on the molar flux at the crystal region during the growth of mercurous bromide ($Hg_2Br_2$) crystals in 1 g and microgravity (${\mu}g$) conditions. It was found that the total molar fluxes decay first-order exponentially with the aspect ratio (AR, transport length-to-width), $1{\leq}AR{\leq}10$. With increasing the aspect ratio of the horizontal enclosure from AR = 1 up to Ar = 10, the convection flow field shifts to the advective-diffusion mode and the flow structures become stable. Therefore, altering the aspect ratio of the enclosure allows one to control the effect of the double diffusive natural convection. Moreover, microgravity environments less than $10^{-2}g$ make the effect of double-diffusive natural convection much reduced so that the convection mode could be switched over the advective-diffusion mode.

• Structural Engineering and Mechanics
• /
• v.24 no.4
• /
• pp.493-508
• /
• 2006

Vibration mode localization and frequency loci veering in disordered coupled beam system are studied in this paper using finite element analysis. Two beams coupled with transverse and rotational springs are examined. Small disorders in the physical parameters such as Young's modulus, mass density or span length of the substructure are introduced in the investigation of the mode localization and frequency loci veering phenomena. The effect of disorder in the elastic support on the mode localization phenomenon is also discussed. It is found that an asymmetric disorder in the weakly coupled system will lead to the occurrence of mode localization and frequency loci phenomena.

• Journal of the Korean Academy of Clinical Electrophysiology
• /
• v.4 no.1
• /
• pp.49-61
• /
• 2006

This study conducted the following experiment to examine and compare transdermal permeation effects according to parameters of ultrasound and physiochemical characteristics of meloxicam. Permeation by ultrasound among these experimental drugs was relatively higher and it was involved in COX-2 inhibition unlike other drugs. Recently use of oral agents has been rapidly increased, but it was not generalized to transdermal agent and this study selected meloxicam that transdermal permeation research using ultrasound was not performed and conducted transdermal permeation experiment with skin of hairless mouse and analyzed permeation with HPLC. It made gel first and analyzed permeation depending on frequency and intensity of ultrasound of meloxicam with the same experimental procedures as the above experiment. The results of this study can be summarized as follows. Transdermal permeation by ultrasound frequency was higher in 1.0 MHz and it was higher as intensity increased. In comparison by parameters of ultrasound, there was similar permeation in $1.0\;W/cm^2$ of continuous mode and $3.0\;W/cm^2$ of pulsed mode and it was effective to high intensity for using pulsed mode. It was found that duty cycle of ultrasound affected transdermal permeation in meloxicam gel used in this experiment and transdermal permeation was higher in used ultrasound as phonophoresis than non-ultrasound for anti-inflammatory effects.

• Journal of Korean Physical Therapy Science
• /
• v.9 no.4
• /
• pp.7-14
• /
• 2002

The drug therapy for rheumatoid arthritis must be maintained constantly or for the whole life but is apt to induce the adverse effects in gastrointestinal or renal system. Therefor, newer methods are paid attention to reduce adverse effects. The thirty-two rat female separated into seven groups depending on the therapy or Freund's adjuvant applied: Normal group(n=8) not received anything, Positive control group(n=8) only received adjuvant, USC group(n=8) received continuous US, USP group(n=8) received pulsed US. The physical and radiological findings by thermal and non-thermal effects of ultrasound were evaluated in groups with continuous mode at 1 MHz, $0.5\;W/cm^2$ for 6 minutes and with pulsed mode (duty cycle 1:9) at 1 MHz, $0.5\;W/cm^2$ for 6 minutes. The result summarized followings. 1. Swelling of forepaw and hindpaw was significantly reduced in USP. 2. Arthritis indices in USP group were significantly reduced than those in PCG. 3. In naked eye and radiologic findings, swelling was significantly prevented in USP group but not in PCG. The change of swelling, arthritis index, gross feature in naked eye, radiologic finding were significantly improved in all groups except for USC group, taking care for using its continuous mode.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.20 no.3
• /
• pp.125-132
• /
• 2010

For typical governing dimensionless parameters of Ar = 5, Pr = 1.16, Le = 0.14, Pe = 3.57, Cv = 1.02, $Gr_s=2.65{\times}10^6$, the effects of thermo physical properties such as a molecular weight, a binary diffusivity coefficient, a partial pressure of component B on solutally buoyancy-driven convection (solutal Grashof number $Gr_s=2.65{\times}10^6$) are theoretically investigated for further understanding and insight into an essence of solutal convection occurring in the vapor phase during the physical vapor transport of a $Hg_2Cl_2-N_2$ system. The solutally buoyancy-driven convection is significantly affected by any significant disparity in the molecular weight of the crystal components and the impurity gas of nitrogen. The solutal convection in a vertical orientation is found to be more suppressed than a tenth reduction of gravitational accelerations in a horizontal orientation. For crystal growth parameters under consideration, the greater uniformity in the growth rate is obtained for either solutal convection mode in a vertical orientation or thermal convection mode in horizontal geometry. The growth rate is also found to be first order exponentially decayed for $10{\leq}P_B{\leq}200$ Torr.

• Advances in nano research
• /
• v.5 no.1
• /
• pp.13-25
• /
• 2017

We examine the total optical dielectric function (TODF) of impurity doped GaAs quantum dot (QD) from the viewpoint of anisotropy, position-dependent effective mass (PDEM) and position dependent dielectric screening function (PDDSF), both in presence and absence of noise. The dopant impurity potential is Gaussian in nature and noise employed is Gaussian white noise that has been applied to the doped system via two different modes; additive and multiplicative. A change from fixed effective mass and fixed dielectric constant to those which depend on the dopant coordinate manifestly affects TODF. Presence of noise and also its mode of application bring about more rich subtlety in the observed TODF profiles. The findings indicate promising scope of harnessing the TODF of doped QD systems through expedient control of site of dopant incorporation and application of noise in desired mode.

• Journal of the Optical Society of Korea
• /
• v.20 no.6
• /
• pp.733-738
• /
• 2016

We calculate optical properties of guided modes of a hybrid-guiding photonic crystal fiber. The design and modeling of such hybrid-guiding PCF is made by replacing air holes with inserts of high refractive index material layer by layer in order. The optical properties such as mode intensity profile, mode dispersion, optical birefringence, confinement loss, and chromatic dispersion during transition of the guiding mechanism are analyzed and discussed. The guided modes in the hybrid-guiding region are also compared with those of reference index-guiding and bandgap-guiding photonic crystal fibers.