• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.2
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• pp.199-207
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• 2015

Solid materials of ammonia sources with SCR have been considered for the application of lean NOx reduction in automobile industry, to overcome complex problems of liquid urea based SCR. These solid materials produce ammonia gas directly with proper heating and can be packaged by compact size, because of high volumetric ammonia density. Among ammonium salts and metal ammine chlorides, calcium ammine chloride was focused on this paper due to low decomposition temperature. In order to make calcium ammine chloride in lab-scale, simple reactor and glove box was designed and built with ammonium gas tank, regulator, and sensors. Basic test conditions of charging ammonia gas to anhydrous calcium chloride are chosen from equilibrium vapor pressure by Van't Hoff plot based on thermodynamic properties of materials. Synthetic method of calcium ammine chloride were studied for different durations, temperatures, and pressures with proper ammonia gas charged, as a respect of ammonia gas adsorption rate(%) from simple weight calculations which were confirmed by IC. Also, lab-made calcium ammine chloride were analyzed by TGA and DSC to clarify decomposition step in the equations of chemical reaction. To understand material characteristics for lab-made calcium ammine chloride, DA, XRD and FT-IR analysis were performed with published data of literature. From analytical results, water content in lab-made calcium ammine chloride can be discovered and new test procedures of water removal were proposed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.9
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• pp.858-865
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• 2011

This paper describes the characteristics of hydrogen generation from solid-state $NaBH_4$ and fuel cell operation for fuel cell aircraft. The solid-state $NaBH_4$ was used for a high hydrogen storage density, and was reacted with hydrochloric acid to generate hydrogen. The hydrogen generation rate for the solid-state $NaBH_4$ reaction was measured at various conditions. As a result, the hydrogen generation rate was increased with the feed rate and concentration of hydrochloric acid, while not be affected by the reaction temperature. A fuel cell was connected with the solid-state $NaBH_4$ hydrogen generator. The stable power output was obtained at the gradual and sudden increases of electric loads.

• Journal of KIISE:Databases
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• v.31 no.2
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• pp.150-162
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• 2004

Moving objects have characteristics that they change continuously their positions over time. The movement of moving objects should be stored on trajectories for processing past queries. Moving objects databases need to provide spatio-temporal index for handling moving objects queries like combined queries. Combined queries consist of a range query selecting trajectories within a specific range and a trajectory query extracting to parts of the whole trajectory. Access methods showing good performance in range queries have a shortcoming that the cost of processing trajectory Queries is high. On the other hand, trajectory-based index schemes like the TB-tree are not suitable for range queries because of high overlaps between index nodes. This paper proposes new TR(Trajectory Riving)-tree which is revised for efficiently processing the combined queries. This index scheme has several features like the trajectory preservation, the increase of the capacity of leaf nodes, and the logical trajectory riving in order to reduce dead space and high overlap between bounding boxes of nodes. In our Performance study, the number of node access for combined queries in TR-tree is about 25% less than the STR-tree and the TB-tree.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.179-189
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• 2008

The performance of Lean NOx Trap (LNT) based on the catalysts of Pt/K/Ba/$\gamma-Al_2O_3$ with proprietary washcoat formulation is studied using a bench flow reactor system. To investigate the effect of temperature and gas hourly space velocity (GHSV) on the nitrogen oxides (NOx) trapping capacity as well as NOx breakthrough time and final ratio of $NO_2$ to NO of LNT, series of adsorption isotherms are carried out with simulated exhaust gases of the lean burn engines. Since typical operation of LNT requires periodic regeneration with a short rich excursion, where the stored or trapped NOx is released and subsequently reduced to $N_2$, the effect of the duration of lean and rich phase and type of reductants on the NOx conversion is investigated. NOx storage capacity and breakthrough time obtained from adsorption isotherms shows a volcano-type dependence on the temperature with a maximum NOx storage capacity occurring $350^{\circ}C$ and with a maximum breakthrough time occurring $400^{\circ}C$ at all GHSVs investigated in this study. Also, maximum ratio of $NO_2$ to NO is obtained at $400^{\circ}C$ with a GHSV of $75,000\;hr^{-1}$ Lean/rich cycle of 100 s lean and 5 s rich used with a concentration of 1.33% of $H_2$ and 4% of CO in the rich phase is found to be optimum at operating temperature of $350^{\circ}C$ and a GHSV of $50,000\;hr^{-1}$.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.2
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• pp.135-138
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• 1998

This paper describes the construction and experimetal results of prototype digital telesounder developed to monitor remotely the fish school entered in setnet. The telesounder consists of the sea station and land station. The former consists of an ultrasonic transceiving part of 50 KHz, a hand made 16 bits single board computer (SBC), and a RF MODEM of 9600 bps for data link. The SBC controls the trigger signal to transmit the ultrasonic pulse, maximum detection range, sampling rate in analog to digital converter and data link. The sampling rate of echo data was 80 ${\mu}$s. The later consists of a RF MODEM same as the former one and 486 notebook computer which displays the echogram and saves its raw data. The authors carried out some experiments to confirm the practical use of the telesounder. At results the echogram obtained on the land station is sufficiently good and clear to monitor the behavior of fish school in setnet.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.4
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• pp.16-21
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• 2001

In this paper a virtual form of 3 dimensional face is synthesized from the two sheets of 2 dimensional photographs In this case two sheets of 2D face photographs, the front and the side photographs are used First of all a standard model for a general face is created and from this model the feature points which represents a construction of face are densely defined on part of ears. eyes, a nose and a lip but the other parts. for example, forehead, chin and hair are roughly determined because of flat region or the less individual points. Thereafter the side photograph is connected symmetrically on the left and right sides of the front image and it is gradually synthesized by use of affine transformation method. In order to remove the difference of color and brightness from the junction part, a linear interpolation method is used. As a result it is confirmed that the proposed model which general model of a face can be obtain the 3D virtual image of the individual face.

• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.690-695
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• 1990

The adsorption characteristics of coffee were mvestigated at $5, 15, 25, and 35^{\circ}C$ under various water activities such as 11, 32, 57, 75 and 90% and prediction models were developed by optimization program. The moisture adsorption isotherm curves were similar to the typical sigmoid type. The values of equilibrium moisture content and the monolayer moisture content were highest in the Freeze Dried, which was due to porous structure by the drying method. In the result of adjusting the isotherm models in this paper, Halsey model generally gave the best fit for isotherms of coffee. Prediction model for equilibrium moisture content was established with water activity and temperature. Adsorption prediction models were also developed with water activity, with water activity and time, and with water activity, time and temperature, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10C
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• pp.813-819
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• 2008

In this paper, we implemented a real-time system which displays 3-dimensional (3D) stereoscopic image with stereo camera. The system consists of a set of stereo camera, FPGA board, and 3D stereoscopic LCD. Two CMOS image sensor were used for the stereo camera. FPGA which processes video data was designed with Verilog-HDL, and it can accommodate various resolutional videos. The stereoscopic image is configured by two methods which are side-by-side and up-down image configuration. After the left and right images are converted to the type for the stereoscopic display, they are stored into SDRAM. When the next frame is inputted into FPGA from two CMOS image sensors, the previous video data is output to the DA converter for displaying it. From this pipeline operation, the real-time operation is possible. After the proposed system was implemented into hardware, we verified that it operated exactly.

• Journal of Digital Convergence
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• v.14 no.1
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• pp.189-194
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• 2016

Recently, there is increasing demand for image processing technology while activated the use of equipments such as camera, camcorder and CCTV. In particular, research and development related to 3D image technology using the depth camera such as Kinect sensor has been more activated. Kinect sensor is a high-performance camera that can acquire a 3D human skeleton structure via a RGB, skeleton and depth image in real-time frame-by-frame. In this paper, we develop a system. This system captures the motion of a 3D human skeleton structure using the Kinect sensor. And this system can be stored by selecting the motion file format as trc and bvh that is used for general purposes. The system also has a function that converts TRC motion captured format file into BVH format. Finally, this paper confirms visually through the motion capture data viewer that motion data captured using the Kinect sensor is captured correctly.

• Journal of Chest Surgery
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• v.30 no.8
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• pp.815-818
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• 1997

Prosthetic valve endocarditis(PVE), although uncommon, is associated with significant mortality if the infection spreads into the paravavular structures with later abscess formation. However, combined antibiotic and surgical treatment is often successful. Accurate diagnosis by on echocardiography, effective myocardial protection during operation and increased surgical experience have improved the short-term and long-term outcomes for patients with PVE. A 35-year-old male had a history of replacement of aortic and mitral valve, and tricuspid annuloplasty on August 1994, was admitted due to sudden onset of aphasia, leftward deviation of both eyeballs and spiking fever and diagnosed of having PVE by echocardiography. Reoperation was done after 6weeks of antibiotic treatment. On the operative field, we could notice circumferential vegetation along aortic valve annulus, paravalvular leakage and abscess pocket. The mitral valve amlulus was healthy. The patient underwent redo aortic valve replacement using cryopreserved aortic homograft after radical debridement of infected issue. During the follow up of 7 months period the homograft was well functioning without recurrence of symptoms.