• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1795-1801
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• 2009

In this study, a portable flashlight which can manually generate the electricity by using sunlight was developed so that it can be used in the extreme environmental condition such as no-electricity condition. Battery is charged by using solar battery during the day, but when sunlight is not avalible during the night or rainy day, a handle is rotated to generate the electricity in order to charge the battery manually. To improve the brightness of the light, light is concentrated by using the optical lens. Low electric consumption circuit is used for the longer operating time by suppress electrical consumption while lamp is discharged. A circuit is designed and used for steady electrical curris dand voltage to insure steady battery charging. Super-discharge circuit and protection circuit are used for the super discharge of battery when it is not used for a long time. Also the constant charge is possible by using houseware adapter. As a result, a portable flashlight is designed to charge with sunlight during day, and with houseware adapter during night. A portable flashlight is also designed to irradiate longer distances by improvement of the brightness of the light using the optical lens. Thus, it forms white natural ray of light making possible for night reading.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.2
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• pp.148-154
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• 2014

Photoelasticity is a useful technique for obtaining the differences and directions of principal stresses in a model. In conventional photoelasticity, the photoelastic parameters are measured manually point by point. Identifying and measuring photoelastic data is time-consuming and requires skill. The fringe phase shifting method was recently developed and has been found to be convenient for measuring and analyzing fringe data in photo-mechanics. This paper presents an experimental study on the stress distribution along a horizontal line that passes the central point of a rhombus plate made of Photoflex (i.e., type of urethane rubber). The isoclinic fringe and/or principal stress direction is constant on this horizontal line, so a four-bucket phase shifting method can be applied. The method requires four photoelastic fringes that are obtained from a circular polariscope by rotating the analyzer at $0^{\circ}C$, $45^{\circ}C$, $90^{\circ}C$ and $135^{\circ}C$. Experimental measurements using the method were quantitatively compared with the results from FEM analysis; the results from the two methods showed comparable agreement.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.380-385
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• 2016

This study analyzed changes in ${\beta}$-glucan content in Agaricus blazei Murill concentrates according to extrusion and extraction conditions. Screw speed and feed rate were fixed to 250 rpm, and 100 g/min, respectively. Moisture contents (20 and 30%) and barrel temperature (130 and $140^{\circ}C$) were adjusted. ${\beta}$-Glucan content of the extruded sample at a moisture content of 20% and barrel temperature of $130^{\circ}C$ was higher compared to other extrusion conditions. ${\beta}$-Glucan content of the extruded sample at a moisture content of 20% and barrel temperature of $130^{\circ}C$ treated with Rohament CL enzyme was higher compared to Viscozyme L, and Plantase TL enzyme treatments under the same extrusion conditions. In conclusion, extrusion and pretreatment with Rohament CL enzyme enhanced yield of ${\beta}$-glucan extract.

• Journal of Korean Medicine Rehabilitation
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• v.29 no.4
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• pp.81-88
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• 2019

Objectives This study is a preliminary study for safe and accurate cervical Hyeopcheok acupuncture by comparing the depth of cervical Hyeopcheok acupoint with cervical spine rotation. Methods Researchers took ultrasonographic images of cervical Hyeopcheok acupoint during full rotation of cervical spine, 45 degree rotation and neutral condition in a prone position. 4 healthy volunteers were recruited. Results No significant difference in needling depth of cervical Hyeopcheok acupoint was observed. However, there were a differences in anatomical structures' shape such as muscles. Conclusions There are no significant difference in needling depth, but anatomical structures' shape were changed. This result mean that if patient rotate cervical spine during acupuncture treatment, it can occur complications. Thus, when acupuncture treatment on cervical Hyeopcheok acupoint, practioner should make subject's cervical spine alignment corrected and be careful not to change posture during the procedure.

• Food Engineering Progress
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• v.21 no.2
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• pp.150-157
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• 2017

The objective of this study was to determine the effect of moisture contents (40, 50, 60%) and $CO_2$ gas injection (0 and 800 mL/min) on physicochemical properties of extruded soy protein isolate (SPI). The expansion ratio and the specific length increased, but piece density decreased with the increase in $CO_2$ gas injection from 0 to 800 mL/min at both 40 and 50% moisture contents. On the contrary, the expansion ratio and the specific length decreased, but piece density increased with the increase in $CO_2$ gas injection from 0 to 800 mL/min at 60% moisture content. Extruded SPI with $CO_2$ gas injection at 800 mL/min had small cell size and higher amount of cell than extruded SPI without $CO_2$ gas injection. The water holding capacity and nitrogen solubility index increased, and the integrity index and the texture decreased with the increase in $CO_2$ gas injection from 0 to 800 mL/min. In conclusion, extruded SPI with the $CO_2$ gas injection at 800 mL/min showed better expansion properties and cell formation than extruded SPI without the $CO_2$ gas injection.

• Food Engineering Progress
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• v.23 no.2
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• pp.118-124
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• 2019

This study aims to investigate the physical properties of extruded psyllium husk upon the addition of emulsifiers. Three different emulsifiers-glycerol monostearate (GMS), polyglycerol ester (PGE), and sugar ester (SE)-were added to the mixture of psyllium husk and rice powder before extrusion. Extrusion was performed using a twin-screw extruder at 140℃ die temperature, 200 rpm screw speed, and 16% feed moisture content. The physical properties of psyllium husk extrudates including expansion ratio, specific length, piece density, texture profile, color properties, water soluble index, and water absorption index were evaluated. It was observed that the expansion ratio was the highest while the specific length and piece density were the lowest in the control which had no emulsifiers. Texture profile analysis showed that the apparent elastic modulus and breaking strength were highest in the extrudate with a PGE of 0.1%. The adhesiveness was found to be lowest in the extrudates with an SE of 0.1% and GMS of 0.5%. Lightness value was highest in the extrudate with a PGE of 0.1%. Color difference, water soluble index, and water absorption index were highest in the control. The results reveal that some physical properties of extruded psyllium husk were improved with the addition of emulsifiers. This finding provides useful information for the development of psyllium snacks with good physical characteristics.

• Food Engineering Progress
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• v.23 no.4
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• pp.283-289
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• 2019

This study was performed to determine the effect of psyllium husk addition on the physical properties of rice extrudates. Rice-based formulations mixed with psyllium husk (0, 7, 14 and 21%) were extruded at a die temperature of 140℃, screw speed of 200 rpm, and moisture content of 20%. As the content of psyllium husk increased, expansion ratio decreased, while piece density and specific length increased. Apparent elastic modulus, breaking strength, adhesiveness, and hardness augmented with an elevation in psyllium husk content. Lightness declined as psyllium husk content furthered, while redness, yellowness, and color difference intensified. Water soluble index and water absorption index increased with an increased amount of psyllium husk. In conclusion, the addition of psyllium affected the expansion of extruded rice snack possessing hard texture, small cells, and sticky texture due to higher water absorption during hydration.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1207-1217
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• 2022

Vegetation indices using the reflectance of selected wavelength, associating with the monitoring purpose such as identifying the progress of crop growth, on the vegetation canopy surface is widely used in the digital agriculture technology. However, the surface reflectance anisotropy can distort the true value of vegetation index related to the condition of surface, even though the surface property be unchanged. That causes difficulty to observe accurately crop growth on the monitoring system. In this study, a simple type goniometer was designed to measure the reflectance from the anisotropic surface according to various zeniths and azimuths of sun and viewing sensor in the field. On the tarp like as Lambertian surface, the reflectance of Blue, Green, Red, Near-Infrared band was similar to the tarps' reflectance properties. However, the reflectance was slightly overestimated in the cloudy day. The relative difference values of vegetation indices on grass were overestimated for the forward viewing and underestimated for the backward viewing. In addition, enhanced vegetation index (EVI) showed less sensitive according to the positions of sun and sensor viewing. Field observation with a goniometer will be helpful to understand the anisotropy characteristics on the vegetation surface.

• Journal of the Korean Society of Radiology
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• v.16 no.4
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• pp.435-442
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• 2022

The heel effect creates a density difference in the X-ray images because the intensity of the anode and cathode side of the X-ray tube is not equal. The purpose of this study is to evaluate the density difference due to the heel effect by rotating the step wedge by 180 degrees and then changing the distance. After fixing the tube voltage and tube current to 72 kVp and 10 mAs, the forward and reverse directions were taken using a step wedge. At this time, the distance (80 cm ~ 130 cm) was taken at 10 cm intervals, and the density value was measured by setting the region of interest for each step of the step wedge through the M6 program. First, the difference in intensity between the anode and the cathode was confirmed through the radiation exposure test. In addition, when the distance (from 80 cm to 130 cm) was changed, the difference in density between the cathode and the anode decreased as the projection distance increased. As a result, images of uniform density can be obtained as the projection distance increases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1848-1856
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• 2013

This study is designed to examine the change in physical properties of extruded brown rice-vegetable mix at different temperatures and $CO_2$ gas injections. Moisture content and screw speed were fixed to 27% and 100 rpm respectively. Die temperatures and $CO_2$ gas injections were adjusted to 60, 80, $100^{\circ}C$ and 0, 150 mL/min, respectively. The ratio of ${\alpha}$-brown rice, brown rice and sugars (oligosaccharides and palatinose) was fixed to 25, 50 and 16%, respectively. Green tea, tomato and pumpkin powder were blended individually at 9%. Specific mechanical energy (SME) input decreased as die temperature for each vegetable addition increased. All extrudates decreased in density and breaking strength, but increased in specific length and water soluble index as $CO_2$ gas injection increased. Elastic modulus decreased as the die temperature and $CO_2$ gas injection increased. Extruded green tea mix with $CO_2$ gas injection at 150 mL/min was larger pore size and higher amount of pore than the tomato and pumpkin extrudates with $CO_2$ gas injection. Cold extrusion with $CO_2$ gas injection at $60^{\circ}C$ die temperature could be applicable for making Saengsik (uncooked food).