• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.581-587
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• 2020

In this study, a new reaction system is proposed to solve the problems of the existing 2,3-Butanediol (2,3-BDO) dehydration reaction system. It was confirmed that the reaction system did not wok as it should operate properly when using a furnace, which is commonly used in commercial processes, to raise the reactant, 2,3-BDO, to the reaction temperature, 360 ℃, at near atmoshperic pressure. It is because of the substance considered to be oligomers of 2,3-BDO. It can lead to safety problems, such as blockages inside the furnace's tube and explosions, as well as tricky maintenance issues in the reaction system. To solve it, the temperature of reactant can be brought down by using a heat exchanger with High Pressure (HP) steam instead of the furnace, which has a hot spot problem through the vacuum operation and reduce the reaction temperature. It can be seen that the reactor performance is almost similar under the vacuum operation and the lower reaction temperature, 330 ℃, by using a reaction kinetics. This result explains why the new reaction system is proposed.

• Journal of the Korean Society for Railway
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• v.13 no.1
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• pp.92-98
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• 2010

Block system has been used to protect trains from occupying the same section of track at the same time so that only one train is permitted in each block at a time. Domestic driving regulations on the block system is divided into two classifications, such as regular block and substitute block. If it is impossible to use this regulation, the block applied method can be applied. However, domestic urban railway administrator has established his own operation rule within the regulation. Therefore, in order to assure continuous safety of train in operation, it is necessary to strengthen the regulation as can cope with the various block systems. In this study, domestic urban railway administration's own rules are examined and the appropriate driving regulation on the block system is proposed.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.2
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• pp.11-17
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• 2013

Nowadays 3D models are used in diverse sectors. The 3D maps provide better reality than existing plane maps as well as diverse pieces of information that cannot be expected from the limited plane maps. A process proposed in this paper enables easy and quick production by replacing the expensive laser scanners for modeling by an improved digital camera stereo matching algorithm. The algorithm used in this study was a SURF algorithm contained in the OpenCV library. The unconformity points of the algorithm were eliminated using the homography conversion and epipolar lines. In addition, the improved algorithm was compared with the commercial program, and it showed a better performance than the commercial program. It is expected that the proposed method can contribute to the digital maps and 3D virtual reality because it enables easy and quick 3D modeling provided that the stereo matching conditions are met.

• Korean Journal of Remote Sensing
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• v.27 no.4
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• pp.411-420
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• 2011

In this study, a digital elevation model (DEM) in tidal flat of Suncheon Bay, one of the most ecological preserved area in the world, was generated from digital aerial stereo-images. The focal lengths for the aerial stereo-images were adjusted using ground control points (GCPs) in order to improve the accuracy of camera parameters. We proposed matching sizes suitable for generating DEM in tidal flat and a method for eliminating excessive position errors using intersection-distance($P_R$) threshold value. The accuracies of the DEM generated from the proposed method as well as the commercial S/W were compared with the elevation profiles measured by Total Station in the filed. As the results, the DEM generated by the proposed method showed better result (maximum deviation is a -21 centimeters) with detailed topography than DEM by the commercial S/W in the region. These results suggest that the DEM of tidal flat, which hardly obtained with the traditional methods, can be generated from digital aerial images by applying the proposed method in this study. We believe that the generated DEM in tidal flat can be an essential data for monitoring the sediment erosion and deposit of the tidal flat.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.2
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• pp.102-108
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• 2009

DO, ORP and pH values measured during SBR operation can provide information about removal reaction of organic contaminants and nutrient materials in the reactor. It is already generalized control strategy to control reaction phase time using their special patterns indicating the end of the removal reactions. However, those informations are limited to point out the end time of oxidative reaction in the aerobic phase or reductive reaction in the anoxic phase without giving quantitative value of influent loading level. In this research, a diagnosis algorithm which can estimate the loading level of carbon and ammonia as high, medium and low was developed using the basic measurements like DO, ORP, and pH. It will be possible to know the level of influent loading rate from those online measurements without experimental analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.254-260
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• 2019

Recently, a self-camera that generates and distributes a large amount of moving images has been rapidly increasing due to the appearance of SNS such as Facebook, Instagram, and Tweet using mobile. In particular, the amount of SNS connections using mobile phones is significantly increasing in terms of usage, number of connections, and usage time. However, the use of a self-recording system using a smartphone by itself is extremely limited not only in terms of usage but also in frequency of use. In addition, the conventional unattended recording system is a very expensive system that automatically records and tracks an object to be photographed using an infrared signal. Therefore, this paper developed a low cost unmanned recording system using mobile phone. The system consists of a commercial mobile camera, a servomotor for moving the camera from side to side, a microcontroller for controlling the motor, and a commercial wireless Bluetooth earset for video audio input. And it is an unmanned automation system using mobile, and anyone can record image by self image tracking.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.6
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• pp.518-521
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• 2019

In this paper, an active antenna module operating in the 60 GHz band is designed and fabricated by combining a commercial transmitter chip and patch array antenna. The designed module is composed of an antenna PCB and a PCB with a transmitter chip. The frequency-control and bias-control signals are applied to the transmitter chip, using an Arduino kit. A baseband I/Q signal is also applied to the chip. A ring hybrid balun converts the output of the transmitter module to a single output, which is the output of the transmitter chip that outputs a differential output. The output is delivered to the $2{\times}4$ microstrip patch array antenna PCB as a micro-computer connector. The radiation pattern of the millimeter-wave signal of the final output is compared with the simulation results. The measured radiation patterns of the fabricated active antenna module confirm that the positions of the 3 dB beam width and null point agree well with the simulation results.

• Convergence Security Journal
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• v.18 no.1
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• pp.33-42
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• 2018

CFD analysis is an analytical technique that applies a computer to the design and development of products across the entire industry for heat or fluid flow. This technology is used to shorten the development period and reduce costs through computerized simulation. However, the software used for CFD analysis is now required to use expensive foreign software. The Opensource CFD analysis software used in the proposed system has reliability of commercial CFD analysis software and has various user groups. However, for users who have expert knowledge, Opensource CFD software which supports only text interface environment, We have developed an environment that enables the construction of a CFD analysis environment for beginners as well as professionals. In addition, the proposed system supports the pre-processing (design and meshing) environment for CFD analysis and the environment for post-processing (result analysis & visualization), enabling the integrated CFD analysis process in one platform.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.362-367
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• 2009

Recently, the use of formic acid as a fuel for direct liquid fuel cells has emerged as a promising alternative to methanol. In the work presented herein, we evaluated direct formic acid fuel cells(DFAFCs) with various components under operating conditions, for example, the thickness of the proton exchange membrane, concentration of formic acid, gas diffusion layer, and commercial catalyst. The thickness of the proton exchange membrane influenced performance related to the fuel cross-over. To optimize the cell performance, we investigated on the proper concentration of formic acid and catalyst for the formic acid oxidation. Consequently, membrance-electrode assembly(MEA) consisted of $Nafion^{(R)}$-115 and the Pt-Ru black as a anode catalyst showed the maximum performance. This performance was superior to the DMFCs' one.

• Journal of Digital Convergence
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• v.11 no.3
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• pp.115-126
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• 2013

The purpose of this study was to confirm the extent of the reduction in the total cost of ownership of the open source software in comparison to the commercial software installed for information system, PC and cloud computing. Accordingly, the actual reduction rates in the total cost of ownership, when open source software is installed in the information system, PC and cloud computing, were computed and analyzed for 51 companies in the area of information system, 18 companies in the area of PC and 6 companies in the area of cloud computing, which included government institution, educational institution and private enterprises. The results of expert survey illustrated that the reduction rates are (1)63.3% on the average for the 4areas of information system, namely, DBMS, WAS, Web and OS, (2) 59.4% on the average for the 6 areas of PC, namely, OS, Documentation Program, Back-up and Restoration, Screen Capture, Vaccine and Others and (3) 61.2% on the average for the 6 areas of cloud computing, namely, Virtualization, OS, WEM/WAS, DBMS, DFS and Cloud Management.