• Journal of Advanced Marine Engineering and Technology
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• v.8 no.2
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• pp.25-38
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• 1984

Since the energy shock in 1973, there have been wide studies for the developments of the alternative energy source, the rationalization of the energy utilization and the energy economy because of the recognition of the limitation of energy source all over the world. This study is experimentally examined in and compared with the engine performance of output, torque and fuel consumption rate, and the exhaust emissions with the change of engine rmp in the cases of using water-gashol blends, gashol and gasoline as a fuel in a conventional 4 cycle 4 cylinder gasoline engine. In the case of using water-gashol blends, it is installed by the exhaust manifold pipe into the intake manifold, and water is injected from nozzle fitted up the air horn of the carburetor. The results are obtained as follows; 1. In the case of an addition with water, the engine output and the torque are little difference with the case of gasoline. 2. The fuel consumption rate is decreased as compared with the case of gasoline. Especially, the decrease in quantity is remarkable at the low rpm. 3. The exhaust emissions are remarkably decreased as compared with the case of gasoline. Especially, decreases of CO and HC in quantity are remarkable at the low rpm, and a decrease of No/sub x/ in quantity is remarkable at the high rpm. 4. There is a moderate condition of operation because the producing factors of NO/sub x/ and CO, HC are contrary to each other.

• Proceedings of the Safety Management and Science Conference
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• 2013.04a
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• pp.655-668
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• 2013

In this study, a combination of the plasma discharge in the reactor by the reaction surface discharge reactor complex catalytic reactor and air pollutants, hazardous gas SOx, change in frequency, residence time, and the thickness of the electrode, the addition of simulated composite catalyst composed of a variety of gases, including decomposition experiments were performed by varying the process parameters. 20W power consumption 10kHz frequency decomposition removal rate of 99% in the decomposition of sulfur oxides removal experiment that is attached to the titanium dioxide catalyst reactor experimental results than if you had more than 5% increase. If added to methane gas was added, the removal efficiency increased decomposition, the oxygen concentration increased with increasing degradation rate in the case of adding carbon dioxide decreased.

• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.560-564
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• 2013

${\small{D}}$-Ribose is a value-added five-carbon sugar used for riboflavin production. To investigate the effects of oxygen supply and mixed sugar concentration on microbial production of ${\small{D}}$-ribose, a transketolase-deficient Bacillus subtilis SPK1 was cultured batch-wise using xylose and glucose. A change of agitation speed from 300 rpm to 600 rpm at 1 vvm of air supply increased both the xylose consumption rate and ${\small{D}}$-ribose production rate. Because the sum of the specific consumption rates for xylose and glucose was similar at all agitation speeds, metabolic preferences between xylose and glucose might depend on oxygen supply. Although B. subtilis SPK1 can take up xylose and glucose by the active transport mechanism, a high initial concentration of xylose and glucose was not beneficial for high ${\small{D}}$-ribose production.

• Journal of Environmental Science International
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• v.22 no.7
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• pp.915-923
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• 2013

Decomposition of non-biodegradable contaminants such as phenol contained in water was investigated using a dielectric barrier discharge (DBD) plasma reactor in the aqueous solutions with continuous oxygen bubbling. Effects of various parameters on the removal of phenol in aqueous solution with high-voltage streamer discharge plasma are studied. In order to choose plasma gas, gas of three types (argon, air, oxygen) were investigated. After the selection of gas, effects of 1st voltage (80 ~ 220 V), oxygen flow rate (2 ~ 7 L/min), pH (3 ~ 11), and initial phenol concentration (12.5 ~ 100.0 mg/L) on phenol degradation and change of $UV_{254}$ absorbance were investigated. Absorbance of $UV_{254}$ can be used as an indirect indicator of phenol degradation and the generation and disappearance of the non-biodegradable organic compounds. Removal of phenol and COD were found to follow pseudo first-order kinetics. The removal rate constants for phenol and COD of phenol were $5.204{\times}10^{-1}min^{-1}$ and $3.26{\times}10^{-2}min^{-1}$, respectively.

• Solar Energy
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• v.19 no.4
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• pp.11-20
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• 1999

The study on ice thermal storage system is to improve total system performance and increase the economical efficiency in actual air-conditioning facilities. To obtain the high charging and discharging efficiencies in ice thermal storage system, the improvement of thermal stratification is essential, therefore the process flow must be piston flow in the cylindrical type. In the influence of the inlet port type, the inflowing water in the distributor type diffuses through the whole storage tank more than in the slot type. In case of the flow process in the ice storage tank, the upward flow type in the charging process and the downward flow type in the discharging process make the stratification well, thereby the loss of energy wored be smaller. The influence of the inlet temperature difference and the change of the inlet flow rate is intensive when the temperature difference is larger, the flow rate is smaller in case of charging and the results are opposite in case of discharging with the reason that the good coduction condition. The total effeciency of the ice thermal storge system is 73% on condition that the porosity in the thermal storage tank is 0.55. This result shows that cylinderical ice storage tank has better storage capacity than rectangular type in case of the same porosity.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.4
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• pp.708-716
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• 1989

The purpose of this study is to investigate the breakup mechanism of a liquid jet in a coaxial air flow. By using the high speed camera, measured were the instantaneous change of the wave length, amuplitude of disturbance, propagation velocity of wave and breakup length, and the relationships between those data were examined. The shape of the surface of the liquid jet appeared to be rather complicated and irregular. The growth rate of disturbance was not constant, and was changed at the moment of 3ms prior to the disintegration of the liquid jet. Simultaneously at this moment, the propagation velocities of the sequential waves were reversed and the wave length was rapidly decreased.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.773-778
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• 2006

Velocity profiles inside a partially filled pipline have been investigated experimentally. To measure the velocity fields, a particle image velocimetry (PIV), which is a recent quantitative visualization technique, is applied. The velocity profile inside a circular pipe is well known, but if the pipe is partially filled, the problem is entirely different in the sense that the velocity distribution is significantly affected by the slope of pipe and filled water level, and so on. In order to calculate exact flow rate in the open channel or partially filled pipeline, three-dimensional velocity distributions at a given cross-sectional area are measured and compared the flow rates with the previously known empirical formula of Manning equation. The results show that the velocity profiles at center plane is considerably different from each other when the slope and water level change. Thus, The three-dimensional velocity profile can be the most plausible estimate for the exact flow rate.

• Journal of Animal Science and Technology
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• v.65 no.6
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• pp.1254-1269
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• 2023

This study aims to predict the change in corn share according to the grazing of 20 gestational sows in a mature corn field by taking images with a camera-equipped unmanned air vehicle (UAV). Deep learning based on convolutional neural networks (CNNs) has been verified for its performance in various areas. It has also demonstrated high recognition accuracy and detection time in agricultural applications such as pest and disease diagnosis and prediction. A large amount of data is required to train CNNs effectively. Still, since UAVs capture only a limited number of images, we propose a data augmentation method that can effectively increase data. And most occupancy prediction predicts occupancy by designing a CNN-based object detector for an image and counting the number of recognized objects or calculating the number of pixels occupied by an object. These methods require complex occupancy rate calculations; the accuracy depends on whether the object features of interest are visible in the image. However, in this study, CNN is not approached as a corn object detection and classification problem but as a function approximation and regression problem so that the occupancy rate of corn objects in an image can be represented as the CNN output. The proposed method effectively estimates occupancy for a limited number of cornfield photos, shows excellent prediction accuracy, and confirms the potential and scalability of deep learning.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.1931-1936
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• 2007

The application of high velocity air jets to heat transfer surface has tremendous engineering potential in various industries. The impinging jets are therefore widely used for their enhanced transport characteristics, especially for drying of continuous materials such as sheet, film, carpets, forming materials and pallets. This paper presents the drying characteristics of plate type material and performs the test with the change of operating conditions in conveyer band dryer using the impinging jet nozzles. The factors influencing drying rate were confirmed, also the design data of band dryer using the impinging jet was obtained.

• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.195-197
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• 2001

The shorted-turn sensor for generator's field winding has been developed. The sensor, installed in the generator air-gap, senses the slot leakage flux of field winding and produces a voltage waveform proportional to the rate of change of the flux. For identification of reliability for sensor, a shorted-turn test was performed at the Seoinchon & Sininchon combined cycle power plant on gas turbine generator. This sensor will be used as a detecting of shorted-turn for generator's field winding.