• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.4
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• pp.15-25
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• 2022

In this study, the efficiency of treatment of moisture and organic matter in food waste was analyzed according to the air blast volume and preheating using the bio-drying method. Te mount of air blast volume and preheating were determined by the evaluation of temperature and CO2 during food waste treatment using the bio-drying method. As a results, the increase in the air blast volume increased the moisture removal efficiency and removal rate, but, lowered the temperature inside the bio-drying by the decease in microbial activity. In order to maintain the activity of microorganisms, it was estimated that it was necessary to inject an appropriate air blast rate according th the properties of the food waste. In this study, the injection of air blast volume at 15L/min was optimal. It was evaluated that the organic matter and water removal rates according to the presence or absence of air preheating, the organic matter removal rate and water removal rate increased by 3-5% when air preheating was not performed. Also, there was no internal aggregation caused by the generation of condensate inside the bio-drying. Therefore, for effective bio-drying of food waste, it is necessary to maintain an appropriate air blast volume to maintain microbial activity, and it is considered that injection through preheating of air is required.

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.312-320
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• 2011

In order to estimate a better methodological factor to understand phytoplankton ecology between abundance and bio-volume of phytoplankton, each 1,160 phytoplankton data, including abundance, classification and chlorophyll $a$ concentration were collected in Korean coastal waters of Incheon (Yellow sea), Tongyeong (South sea), and Ulsan (East sea). Based on these data, phytoplankton bio-volume can be calculated through a geometric model. The correlation coefficient between abundance and chlorophyll $a$ concentration was higher than the coefficient between biovolume and chlorophyll $a$ concentration, because a small size phytoplankton has relatively dense chlorophyll contents compared with the proportion of chlorophyll in a large size phytoplankton. Thus, the interpretation using abundance to understand phytoplankton ecology in Korean coastal waters may be more effective than that using bio-volume.

• Korean Journal of Environmental Biology
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• v.30 no.1
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• pp.1-8
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• 2012

To understand growth characteristics of eight dominant red tide species ($Prorocentrum$ $minimum$, $Heterocapsa$ $triquetra$, $Scrippsiella$ $trochoidea$, $Akashiwo$ $sanguinea$, $Chattonella$ $marina$, $Heterosigma$ $akashiwo$, $Amphidinium$ $carterae$ and $Rhodomonas$ $salina$) in the Korean coastal water, the growth rates were examined in relation with the impacts of water temperature and bio-volume. Of these, $P.$ $minimum$, $C.$ $marina$, $H.$ $akashiwo$, $A.$ $carterae$ and $R.$ $salina$ were eurythermal species with relatively high growth rates in a borad ranges (15 to $25^{\circ}C$) of water temperature. On the other hand, the growth rate of $H.$ $triquetra$, $S.$ $trochoidea$ and $A.$ $sanguinea$ were high in relatively mid temperature (optimum: $25^{\circ}C$) condition. In particular, $H.$ $triquetra$ was well adapted in low temperature of 5 to $15^{\circ}C$, implying that the species can survive and grows even at very low temperature. Based on results of our experiment, the growth characterestics of five eurythermal species and three mid temperature species may have dominated in Korean coastal water during summer season and fall season, respectively. Contrastively, the growth characteristics of $H.$ $triquetra$ make a consistently dominant during the cold winter season. In addition, the growth rates of large bio-volume species were lower than those of small bio-volume species, indicates that growth of single cells of several flagellates might be depended on the cells sizes.

• Journal of the Semiconductor & Display Technology
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• v.18 no.4
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• pp.129-133
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• 2019

In this paper, we developed a system to monitor the storage capacity of suction-type device such as vacuum cleaner or crop harvesters. The monitoring system consists of load cells and a differential pressure sensor which simultaneously monitor the weight and volume of the stock. Since weighing objects stored in storage containers alone cannot fully monitor the level of filling, more accurate monitoring can be achieved by monitoring volume and fusion with weight information. The volume was monitored using a phenomenon in which the flow rate of the inhaled air varies depending on the volume of the object filled in the storage container. In this paper, we developed a system to monitor the storage in three stages: low, medium and high.

• Journal of ILASS-Korea
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• v.13 no.4
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• pp.206-211
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• 2008

In this research, combustion and spray characteristics were investigated experimentally in a constant volume chamber by applying bio-diesel fuel to a common-rail system in which precise control is available for utilizing environmentally friendly properties of bio-diesel fuel. The experiment was conducted at fuel temperatures $20^{\circ}C$ and $-20^{\circ}C$ to investigate combustion characteristics of bio-diesel fuel provoking problems in fluidity specially in a low temperature. For the visualization, the experiment was carried out under various conditions of ambient pressure, injection pressure and fuel temperature. The test was made by three different types of diesel fuels, conventional diesel, BD20 and BD100. In summary, this research aims to investigate combustion characteristics in the application of bio-diesel fuels and compare the results with performance of conventional diesel fuel. This experimental data may provide fundamentals of spray and combustion of bio-diesel fuels at a low temperature and contribute to the development of bio-diesel engines in future.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.365-366
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• 2013

• Journal of the Korean Society of Industry Convergence
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• v.22 no.1
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• pp.1-9
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• 2019

In electric agricultural machine the gearbox is used to increase torque and lower the output speed of the motor shaft. The gearbox consists of several shafts, helical gears and spur gears works in series. Optimization plays an important role in gear design as reducing the weight or volume of a gear set will increase its service life and improve the bearing capacity. In this paper the basic design parameters for gear like shaft diameter and face width are considered as the input variables. The bending stress and material volume is considered as the objective function. ANSYS was used to investigate the bending stress when the variable was changed. Artificial Neural Network (ANN) was used to obtain the mathematical model of the system based on the bending stress behaviour. The ANN was used since the output system is nonlinear. The Genetic Algorithm (GA)　technique of optimization is used to obtain the optimized values of shaft diameter and face width on the pinion based on the ANN mathematical model and the results are compared as that obtained using the traditional method. The ANN and GA were performed using MATLAB. The simulation results were shown that the proposed algorithm was successfully calculated the value of shaft diameter and face width to obtain the minimal bending stress and material volume of the gearbox.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.5
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• pp.665-671
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• 2012

The purpose of this study is to examine the effect of Vigna angularis ethanol extract (VA-E) on papain induced arthritis in C57BL/10 mice. The C57BL/10 mice were injected with papain and oral administration of Vigna angularis ethanol extract (VA-E) at different doses (100 and 200 mg/kg) once a day for 42 days and compared with untreated mice. Histological examination and the measurement of inflammatory cytokine release were performed. The results showed that comparing with untreated mice, the treatment with Vigna angularis ethanol extract (VA-E) decreased the pathological changes of knee joint tissue. The level of inflammatory cytokine secreted from the tissues, such as IL-$1{\beta}$ (interleukin-$1{\beta}$), IL-6 (interleukin-6), TNF-${\alpha}$ (Tumor Necrosis Factor-${\alpha}$), were decreased. These results were confirmed by the quantification of cartilage volume using micro CT scanning. Consequently, Vigna angularis ethanol extract (VA-E) has a therapeutic potential in inflammatory joint diseases such as osteoarthritis.

• Korean Journal of Agricultural Science
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• v.44 no.4
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• pp.487-494
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• 2017

Spinosad and spinetoram are widely used insecticides for the control of lepidopteran larvae, leaf miners, and thrips; however, they might also have low toxicity toward beneficial insects like bees. Because these pesticides are easily photolyzed by ultraviolet radiation, the QuEChERS method, with its simple pretreatment procedure, is often used for analyzing residues of spinosad and spinetoram. The present study performed a residue analysis using a modified QuEChERS method by pretreating with ammonium salt. The limit of detection (LOD) of the modified method was 0.05 mg/kg and the limit of quantification (LOQ) was 0.25 mg/kg. The coefficient of determination ($R^2$) for the calibration curve was 0.999. Also, we examined any change in the adhesion of spinosad and spinetoram on the plants depending on a spray volume. The adhesion was approximately 70% when the spray volume was increased from 60 L to 120 L per 10 a whereas the adhesion was approximately 37% when the spray volume was increased from 125 L to 250 L. This showed that the amount of adhesion decreased with the higher spray volume. The efficacy result of spinetoram was that over 90% of Frankliniella occidentalis was controlled with the application volume of 125 L per 10 a. Therefore, the result of this study indicates that control of insects is effective and sufficient with a spray volume of 125 L per 10 a in paprika cultivation facilities.

• Journal of Sensor Science and Technology
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• v.21 no.1
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• pp.53-58
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• 2012

Biological and chemical assays(e.g., clinical tests for medical diagnosis) are needed to handle small liquid volume with high accuracy and high reliability. Many micro-dispensing systems using various actuation methods have been developed and applied. In this research, we confirm repeatability of the cartridge-type dispensing system with various measuring methods for guarantee of an acceptable reliability. We systematically examine the dispensed volume variation and dispense rate during 500,000 shots of sequential actuation. Using the same method, we confirm the repeatability of dispensed volume while varying operating conditions and design parameter(i.e., outlet size) of the dispensing system. Also, we examine the consistency of the dispensed volume of droplet while varying the operating pressures. Furthermore, we repeatedly measure differences between an actual dispensed volume and a target volume. According to our results, it is expected that the stable and reliable performance of our dispensing system can effectively be used in various applications containing bio-solutions.