• Journal of the Korean Society of Physical Medicine
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• v.4 no.3
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• pp.165-174
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• 2009

Purpose：This study was performed for effects of gait training on treadmill and stable surface which influenced on the lower limbs muscular activity needed in gait, plantar foot pressure with hemiplegic patients caused by cerebrovascular accident. Methods：Two groups of adult hemiplegia(n=20) were allocated randomly in this study: treadmill gait training group and control group. The gait training program was provided to experimental groups for 8 weeks (5 times a week). Measurements of pre and post experiment were plantar foot pressure. For measuring muscular activation rectus femoris, biceps femoris, tibialis anterior, gastrocnemius were detected. Results：The results of this study showed that in comparison of pre and post changes of gait training, the treadmill gait training group has noticeable changes than other groups in activity of rectus femoris and tibialis anterior, the control group revealed statistically significant differences in plantar foot pressure Toe2-5, M1, M3, M5, MF area, activity of gastrocnemius. Conclusion：These results mean gait training resulted by treadmill, stable surface provides effective muscle activation and plantar foot pressure with stroke.

• The Korean Journal of Pain
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• v.4 no.2
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• pp.133-136
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• 1991

Stellate ganglion block was performed in 15 patients with intractable glaucoma by injection of 8 ml of 1y lidocaine. The followings are the changes of intraocular pressure(mmHg): Pre -block $32.26{\pm}4.44$ 10 minutes after block $36.80{\pm}4.60$ 20 minutes after block $32.61{\pm}4.41$ 30 minutes after block $28.87{\pm}4.30$ 60 minutes after block $24.73{\pm}4.37$ 120 minutes after block $26.87{\pm}3.18$ 180 minutes after block $31.40{\pm}3.76$ The pressure rose up to 10 minutes post block and significant pressure descent was noticed from 30 minutes post-block. Maximum descent was seen by 60 minutes post-block and pre-block pressure was restored by 180 minutes post-block. For the purpose of cheeking the treatment effect, similar blocks were performed in 15 patients, one time daily for 5~8 days 3 times every othor day.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.54-58
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• 2001

In recent years, hydroforming technology has been one of the most important technology in automotive industry in the points of weight saving, cost reduction and qualify improvement. However, compared with traditional metal forming technology, hydroforming has much fewer information in experience and empirical knowledge. But we don't have my sufficient time and money to produce hydroforming products using real blank directly Therefore Simulation is essential in hydrofonrung technology development. In this paper, we simulate the side member as the tubular hydroforming technology. The manufacturing process of side member' consists of pre_bending, pre_forming, and hydroforming of a thin tube. Variables such as internal pressure, end feeding, and tool geometry are optimized to improve the forming safety. And we simulate side member according to several lubricant conditions. from those simulations, we find that strain distributions can be reduced well by internal pressure and end feeding control, and lubrication is the most important thing in hydroforming process.

• Advances in aircraft and spacecraft science
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• v.1 no.1
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• pp.27-41
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• 2014

An active flow control technique based on "smart-tabs" is proposed to delay flow separation on a circular cylinder. The actuators are retractable and orientable multilayer piezoelectric tabs which protrude perpendicularly from the model surface. They are mounted along the spanwise direction with constant spacing. The effectiveness of the control was tested in pre-critical and in post-critical regime by evaluating the effects of several control parameters of the tabs like frequency, amplitude, height, angular position and plate incidence with respect to the local flow. Measurements of the mean static pressure distribution around the cylinder were used to estimate the pressure drag coefficient. The maximum drag reduction achieved in the pre-critical regime was of the order of 30%, whereas in the post-critical regime was about 10%, 3% of which due to active forcing. Furthermore, pressure fluctuation measurements were performed and spectral analysis indicated an almost complete suppression of the vortex shedding in active forcing conditions.

• PNF and Movement
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• v.19 no.3
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• pp.375-382
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• 2021

Purpose: The objectives of the present study were to investigate the disadvantages of tire pressure asymmetry of a wheelchair tire and recommend the criterion for appropriate tire pressure without generating negative changes in the musculoskeletal system in asymptomatic participants. Methods: Fourteen asymptomatic participants were asked to sit in pressure-controlled wheelchairs and perform desk work for 20 minutes in each tire condition. The asymmetry of the tire conditions was set as 0% difference, 25% difference, and 50% difference from the recommended pressure. The pelvic alignment and muscular recruitment represented as a flexion-relaxation ratio (FRR) were measured at pre-test, and after each condition of desk work. The displacement of the center of pressure (COP) was measured during the desk work. Results: The tire air pressure condition significantly affected the FRR and COP (P < 0.05). Both sides of the FRR values were significantly higher under the symmetrical tire conditions (0% difference) and pre-test, compared with the asymmetrical tire condition of 50% difference (P < 0.05). The mediolateral COP displacement of the asymmetrical tire conditions (25% and 50% difference) was significantly higher than that of the symmetrical tire conditions (0%) (P < 0.05). Conclusion: Asymmetrical tire conditions could cause changes in the muscle recruitment pattern of the erector spine and mediolateral COP displacement. Tire pressure asymmetry higher than 50% could be a risk factor for prevalence of back pain, so this level of asymmetry in tire pressures should be cautioned against for wheelchair users.

• Journal of the Korean Society of Combustion
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• v.2 no.1
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• pp.17-27
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• 1997

It is well known that NOx formation has a strong dependence on the maximum temperature and correspondingly with the maximum chamber pressure of a closed combustion system. However, in a case of impinging-jet-flame (IJF hereafter) combustion with opposed dual pre-chambers, low $NO_x$ formation with high pressure could be achieved, but its mechanism has not been clearly understood so far. In this study, a three-dimensional analysis is adopted to resolve time-variant local properties that might indicate the mechanism of IJF combustion. Numerical results are verified by comparing them with experiments. The IJF combustion in a vessel with no pre-chamber, with single pre-chamber, and with dual pre-chambers is studied. The orifice diameter and the volumetric ratio of pre-chamber are used as geometric parameters. The effects of main-chamber ignition delay time and combustion time of main-chamber, orifice exit velocity, orifice exit temperature, turbulent kinetic energy of main-chamber and spatial distribution of temperature in the latter stage of combustion are investigated. A longer main-chamber ignition delay and a shorter main-chamber combustion time suppress the formation of high temperature region with respect to mean temperature, which consequently results in less NO production.

• Journal of Korean Society on Water Environment
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• v.21 no.2
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• pp.196-204
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• 2005

The objective of this study is to evaluate the possibility to apply pre-ozone and membrane system for drinking water. This system is improved in fouling control by pre-ozone system. It is composed of ultrafiltration hollow fiber type membrane and ozone reactor. The result of this study is that the flux is increased about 10.7% and decreased in TMP by the pre-ozone. Also, backwashing pressure decreased about 18%. The optimum concentration of residual ozone is 0.3~0.5 ppm. During the period, the recovery ratio of this system was turned out to be 90% as the flowrate of effluent is $67.1m^3/day$. When the TMP and backwashing pressure was $0.85kg/cm^2$ and $1.10kg/cm^2$, this system was stable without sudden fouling. Finally, the quality of effluent is satisfied the guidelines for potable water quality such as turbidity, color, E.coli, Mn, Al, Fe and so on.

• Membrane Journal
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• v.9 no.4
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• pp.193-201
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• 1999

The object of study were the development of membrane process and the optimization of operation condition for membrane system, which was used the pre-treatment system of tap water treatment in steady of conventional process such as coagulation, sedimentation. The higher steady flux is very important factor, by a suitable pre-treatment and optimization of operating condition such as fouling control, crossflow and backwashing method, in membrane system. So, we were observed the effect of flux decline for membrane used by 4 type ultrafiltration(UF) membrane pre-treatment process, and optimized the operation condition of filtration system under various MWCO(Molecular weight cut-off), operation pressure, linear velocity and temperature to maintain higher flux. From these experiment, we were identified that UF process showed a slower flux decline rate and a higher flux recovery than microfiltration(MF) membrane. The water quality of UF permeate was better than that of MF, and was not effected pre-treatment process. In the operation condition, the rate of flux decline was diminished by a higher linear velocity and operation temperature, lower pressure.

• Journal of Acupuncture Research
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• v.25 no.5
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• pp.59-68
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• 2008

Objectives : The purpose of this study is to investigate the effects of $GB_{41}$ supplementation and $BL_{66}$ draining on changes in cerebral blood flow in normal rats. Methods : Regional cerebral blood flow(rCBF) and mean arterial blood pressure(MABP) in normal rats are observed, and those mechanisms were also investigated with pre-treatment of indomethacin(IDM) and methylene blue(MTB) each. Results : In this study, $GB_{41}$ supplementation and $BL_{66}$ draining elevated rCBF in time-dependent manner. Pre-treatment with indomethacin(IDM), an inhibitor of cyclooxygenase, inhibited increase of rCBF effectively. But pre-treatment with methylene blue(MTB), an inhibitor of guanylate cyclase, didn't affect rCBF levels. In addition, pre-treatment with IDM also decreased MABP levels. Conclusions : In conclusion, these results suggest that $GB_{41}$ supplementation and $BL_{66}$ draining is effective to increase rCBF, and the mechanisms are thought to be related to cyclooxygenase pathways.

• International Journal of Automotive Technology
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• v.7 no.1
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• pp.17-23
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• 2006

An experimental study was carried out to obtain the fundamental data about the effect of sub-chamber on pre-mixture combustion. A eve (constant volume combustor) divided into a sub-chamber and a main chamber was used in this experiment. The volume of the sub-chamber was varid trom $0.45\%$ to $1.4\%$ about the whole combustion chamber. The sub-chamber has twelve narrow radial passage holes and a spark plug to ignite the pre-mixture. As the ignition occurs in the sub-chamber by a spark discharge, burned and unburned gas including a great number of radicals is injected into the main chamber, then the multi-point ignition occurs in the main chamber. The combustion pressure is measured to calculate the burning velocity mainly as a function of the sub-chamber volume, the diameter of the passage holes, and the equivalence ratio. In the case of RI (radical ignition) methods, the overall burning time became very short and the maximum burning pressure was slightly increased as compared with that of SI (spark ignition) method. The optimum design value of the sub-chamber is near 0.11 $cm^{-l}$ in the ratio of total area of holes to the sub-chamber volume.