• Journal of Korean Physical Therapy Science
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• v.11 no.3
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• pp.38-48
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• 2004

The purpose of present study is to examine the relative efficacy of active exercise programs for work-related chronic low back pain and to figure out how much they affect mechanical stability of lumbar. Subjects are 43 employees with work-related chronic low hack pain, and they were randomly divided into two groups with general physiotherapy groups and thoracic exercise groups for increasing thoracic mobility. Active exercise programs were done 3 times a week, for 6 months, and the subjects were tested for Pain intensity(VAS), the Oswestry Disability Index, Maximal stretching with both hands in the overhead direction and the lumbar region angle of inclination. All subjects were reassessed with same measurement with Pre-study and 6 months after study After applying active exercise programs, pain intensity didn't show any significant difference between two groups. The Oswestry Disability Index showed significant difference between two groups and thoracic exercise groups decreased significantly compare to general physiotherapy group(p<0.05). Maximal stretching with both hands in the overhead direction showed significant difference between two groups and thoracic exercise group increased significantly more than general physiotherapy groups(p<0.05). The lumbar region angle of inclination showed significant difference between two groups and thoracic exercise group decreased significantly more than general physiotherapy groups (p<0.05). According to the results above, exercise for increasing thoracic mobility has an effect on lumbar stability. For the work-related chronic lower hack pain workers, it is far more effective for lumbar stabilization than general physiotherapy.

• Korean Journal of Optics and Photonics
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• v.10 no.3
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• pp.248-253
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• 1999

In this paper, we have investigated a fiber type active coupler which utilizes the mode coupling between the side polished single mode optical fiber and the active multimode planar waveguide. The proposed device can be used for not only tunable wavelength filter or optical intensity modulator but also a tool for measuring optical properties of guiding material such as refractive index, birefringence, electro-optic coefficient, and thermo-optic coefficient. We gave designed and optimized a coupler structure using the BPM and fabricated the device using thermo-optic polymer as active planar waveguide overlay. The device showed that insertion loss was less then 0.5 dB, extinction ratio was -13 dB at the resonance wavelength, and the wavelength tunablity due to thermo-optic effect was -1.5 nm/$^{\circ}C$. The active coupler using thermo-optic effect can be used as a wavelength tunable filer, an optical intensity modulator and an optical sensor. pulses that are subsequently compressed by a dispersive optical fiber. Experimental results show that $sech^2$ shape pulses with a pulse width of ~14 ps and a time bandwidth product of ~0.34 are successfully generated at 10 GHz repetition rate. In contrast to other methods, such as higher order soliton compression, this approach does not depend on the optical power and thus shows promise for application to low-power lasers.

• Journal of KSNVE
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• v.4 no.2
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• pp.231-238
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• 1994

This paper presents an experimental method to find the vibrational transmission characteristics of structures by using the structural intensity method which is used as the important techniques of active vibration control method. Experimental results are obtained from measurements performed on a structure beam by 2, 3 and 4 position linear accelerometr array (2, 3 and 4 structural intensity : 2, 3 and 4 S.I.) methods at near and farfield conditions. These results are compared with the measurement values of conventional power flow measurement method called input power measurement in order to verify the accuracy of structural intensity methods. To minimize the errors associated with 2, 3 and 4 S.I. methods, the measurement locations were selected by the result of modal analysis and the averaged data by the inter-change of accelerometer array was utilized. In 3 and 4 S.I. methods measured wavenumber instead of theoretical wavenumber was used. This paper shows that measurements of bending wave power flow by using 2, 3 and 4 S.I. methods can give accurate values under general field conditions in structural beam and the accuracy of 2, 3 S.I. methods is higher than 4 S.I. methods. Finally, 2 position linear accelerometer array method is suggested as the practical structural intensity technique.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.11
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• pp.2944-2953
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• 1994

Active range finders using laser beam have been widely used for the factory automation and quality assurance, but they may be unreliable if the object' slope is steep or its surface is specular. The reliability of an active range finder was analyzed for the variation of the reflected laser beam intensity. First, the properties of the object's reflection were modeled by using the bidirectional reflectance-distribution function(BRDF), and then the variation of the laser beam brightness was formulated for the different configuratioin of the object and sensor. The experimental data of the laser beam reflection were obtained for two materials, mild steel and stainless steel. The parameters of the proposed model were obtained by fitting the data of the mild steel to the model and it was found that the results calculated from the proposed model were in good agreement with the experimental data.

• Journal of International Academy of Physical Therapy Research
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• v.8 no.1
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• pp.1071-1076
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• 2017

The purpose of this study was to determine if a gentle form of manual lumbar traction could reduce painful lumbar motions associated with lumbar disc degeneration (LDD). This clinical trial incorporated 134 participants with painful active lumbar motion. Participants were randomly assigned to an experimental treatment or sham group. 67 participants received sidelying manual lumbar traction while the other 67 participants received a sham treatment. Pre and post treatment NPRS values for the painful active lumbar motion were recorded for each group. There was a statistically significant improvement (P=0.00) for decreased pain intensity during active lumbar motion in the experimental group as compared to the sham treatment group. The average percent decrease in numeric pain rating scale (NPRS) values was 52.1% for the experimental treatment group and 8.1% for the sham group. The results of the study suggest that side-lying manual lumbar traction can improve painful lumbar motion in patients with LDD.

• Korean Journal of Optics and Photonics
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• v.11 no.6
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• pp.423-428
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• 2000

We have demonstrated a -8 dB additional reduction in the intensity sidelobe of an apodized-interaction-strength guide-wave acousto-optic filter with a center passband of 1551.6 nm. Acoustic-intensity weighting was achieved by launching a surface acoustic wave (SAW) beam in a straight acoustic waveguide, and gradually transferring this SAW intensity to the active device, and back out, by evanescent-wave coupling across a 50 !lm barrier over a 19 rom interaction length. The intensity sidelobe was -4.27 dB for an unapodized filter with abmpt onset and cutoff of the interaction, but sidelobes were reduced to at most -12.68 dB for a SAW intensity with raised-cosine weighting. The RF driving power was 17.78 mW. A linear tuning rate of 8.86 nmIMHz and a spectral width of -1.7 nm were demonstrated. rated.

• KSTLE International Journal
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• v.1 no.1
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• pp.8-11
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• 2000

A surface crack in a semi-infinite body under Hertzian contact was considered. The simplified method used to estimate stress intensity factor K for specimen was extended to the model which is chosen in this paper. Very satisfactory results are obtained comparing with those known and it is proved that the method is more convenient than other methods. The results of the analysis show that due to the presence of $K_I$ for unlubricated condition, mode I fracture is active in the field below the surface and the maximum $K_{I}$ is obtained when the trailing edge of Hertzian contact reaches a position over the crack. The magnitudes of stress intensity factors $K_I$ and $K_Il$ increase with increasing friction forces. For a surface crack perpendicular to the contact surface, the stress intensity factor $K_I$ reaches its maximum value at a depth very close to the surface. Driving forve fer crack initiation and propagation is $K_I$ for unlubricated condition and $K_Il$ for both fluid and boundary lubricated condition.n.

• Applied Chemistry for Engineering
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• v.19 no.2
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• pp.236-241
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• 2008

The possibility of silicon oxidation through the aerial-diffusion of active oxygen species has been evaluated. The species originate from the surface of $TiO_2$ exposed by UV. Among process parameters such as UV intensity, substrate temperature and chamber pressure with oxygen, UV intensity was a major parameter to the influence on the oxide growth rate. When 1 kW high pressure Hg lamp was used as a UV source, the growth rate of silicon oxide was 8 times as faster as that of a 60 W BLB lamp. However, as the chamber pressure increased, the growth rate was declined due to the suppression of aerial diffusion of active oxygen species. According to the results, it could be confirmed that the aerial-diffusion of active oxygen species from UV-irradiated photocatalytic surface can be applied to a new method for preparing an ultra-thin silicon oxide at the range of relatively low temperature.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.4
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• pp.1064-1071
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• 1994

There are three active radicals which become to the scale of flame diagnostics at the flame front. They are OH, CH and $C_2$ radical. For this, optical measurement system which could monitor simultaneously the luminous waves of three radicals, was constructed. These were analyzed statistically into the cross correlation, coherence and phase. Through such an statistical treatment, combustion characteristics was investigated at the primary zone of gas turbine combustor. The local equivalence ratio was predicted with the ratio of luminuous intensity between CH and $C_2$ radical. This result was matched up to the equivalence ratio calculated from gas composition within 5% error. In general, equivalence ratio was said to be 1.0 at flame front, but it could be increased up to about 1.2 depending on the degree of swirl intensity in case of changing properly the air amount of primary zone.

• Food Science and Biotechnology
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• v.14 no.5
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• pp.689-693
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• 2005

Different masking materials were evaluated for their ability to ameliorate odor of model poultry manure solution by assessing their effects on sensory pleasantness and odor intensity. Results indicated extracts from Eastern red cedar leaves, Loblolly pine needles', and commercial masking agents such as pine extract and odor neutralizer were effective (p<0.05) for masking odor of model poultry manure solution by increasing (p<0.05) pleasantness (82 and 86% increases in pleasantness using red cedar and pine needle extracts, respectively) and decreasing (p<0.05) odor intensity (odor intensity reduction by 66 and 76% using red cedar pine needle extract). The most odor-active compound in Loblolly pine needle extract was ${\alpha}$-terpineol (1,573.8 ug/g) which is responsible for aroma of pine trees (piney) and effective for ameliorating agricultural odors.