• Journal of Hydrogen and New Energy
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• v.15 no.1
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• pp.39-45
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• 2004

A 12-cell PEMFC stack was fabricated using the TiN-coated 316 stainless steel bipolar plates as substitute for the expensive and brittle graphite bipolar plates. Open cirtuit voltage and the maximum power of the stack was 12.08 V and 1.197 kW (199.5 A @ 6 V), respectively. Volumetric and gravimetric power density of the stack was calculated to be 373 W/L and 168 W/kg, respectively. Performance of each cell was quite uniform initially while degraded at a singnificantly different rate. During the 1,000 hr-operation at a constant load of 48 A, stack voltage decreased from 9.0 to 7.98 V at a degradation rate of 11 %/1,000 hr. However, degradation rate of each cell was in the wide rage from 1.2 to 31 %/1,000 hr.

• The KIPS Transactions:PartB
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• v.16B no.3
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• pp.239-246
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• 2009

In this paper, we propose a Korean character recognition method from outboard signboard images. We have chosen 808 classes of Korean characters by an analysis of frequencies of appearance in a dictionary of signboard names. The proposed method mainly consists of three steps: feature extraction, rough classification, and coarse classification. The first step is to extract a nonlinear directional segments feature, which is immune to the distortion of character shapes. The second step computes an ordered set of 10 recognition candidates using a minimum distance classifier. The last step reorders the recognition candidates using a Fisher discriminant measure. As experimental results, the recognition accuracy is 80.45% for the first choice, and 93.51% for the top five choices.

• Journal of Chest Surgery
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• v.30 no.11
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• pp.1149-1153
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• 1997

Unilateral reexpansion pulmonary edema(RPE) is generally considered a rare complication occurring when a chronically atelectatic lung is rapidly reexpanded by tube thoracostomy or thoracentesis. It can also take place when the lung collapse is of short duration or when the lung is reexpanded without intrapleural sucti n. We experienced a case of RPE following surgical resection in mediastinal thymic cyst A 26 year old female patient suffered from long-standing atelectasis of the right lung due to a huge mediastinal cyst that was misrecognized as tuberculous pleural effusion. Empyema developed after iatrogenic rupture of mediastinal cyst by pig-tailed tube thoracostomy. We successfally managed the ruptured mediastinal thymic cyst, empyema and postoperatively developed RPE following reexpansion of the collapsed lung. The patient was treated with drugs and mechanical ventilation with positive end-expiratory pressure for RPE. The remainder of her hospital course was uneventful.

• Journal of Digital Convergence
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• v.14 no.4
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• pp.349-353
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• 2016

The studies on the human environment and ecosystem analysis is being actively researched. In recent years, The service of genome analysis has been offering the customized service to prevent the disease as reading an individual's genome information. The genome information by analyzing technology is being required accurate and fast analyses of ecosystem-dielectrics due to the spread of the disease, the use of genetically modified organism and the influx of exotic. In this paper the algorithm of K-Mean clustering for a new classification system was utilized. It will provide new dielectrics information as quickly and accurately for many biologists.

• Journal of Welding and Joining
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• v.25 no.5
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• pp.45-50
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• 2007

The Ni-base superalloy GTD111 DS is used in the first stage blade of high power land-based gas turbines. Advanced repair technologies of the blade have been introduced to the gas turbine industry over recent years. The effect of the filler metal powder on Transient Liquid Phase bonding phenomenon and tensile mechanical properties was investigated on the GTD111 DS superalloy. At the filler metal powder N series, the base metal powders fully melted at the initial time and a large amount of the base metal near the bonded interlayer was dissolved by liquid inter metal. Liquid filler metal powder was eliminated by isothermal solidification which was controlled by the diffusion of B into the base metal. The solids in the bonded interlayer grew from the base metal near the bonded interlayer inward the insert metal during the isothermal solidification. The bond strength of N series filler metal powder was over 1000 MPa. and ${\gamma}'$ phase size of N series TLP bonded region was similar with base metal by influence of Ti, Al elements. At the insert metal powder M series, the Si element fluidity of the filler metal was good but microstructure irregularity on bonded region because of excessive Si element. Nuclear of solids formed not only from the base metal near the bonded interlayer but also from the remained filler metal powder in the bonded interlayer. When the isothermal solidification was finished, the content of the elements in the boned interlayer was approximately equal to that of the base metal. But boride and silicide formed in the base metal near the bonded interlayer. And these boride decreased with the increasing of holding time. The bond strength of M series filler metal powder was about 400 MPa.

• Tuberculosis and Respiratory Diseases
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• v.67 no.5
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• pp.467-470
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• 2009

A traumatic pulmonary pseudocyst is a rare complication of blunt thoracic trauma. The clinical symptoms and signs are similar to other respiratory diseases, such as pulmonary tuberculosis. Therefore, a trauma history with the resulting radiologic and clinical findings is important for making a diagnosis. A 26-year-old male was admitted to our hospital due to cough for 3 days. The chest x-ray revealed diffuse infiltrations and a cavitary lesion at the left lung. His left chest had hit a tree as a result of motorcycle accident one day before admission. Initially, it was assumed that his symptoms and chest X-ray might be due to a tuberculosis infection. However, bronchoscopy revealed old blood clots at both lungs, particularly in the left lower lobe bronchus. A transbronchial lung biopsy showed alveolar hemorrhage. A traumatic pulmonary pseudocyst was diagnosed from his trauma history and these findings. Computed tomography of the chest performed 4 months later showed regression of the cavitary lesion.

• Journal of Broadcast Engineering
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• v.26 no.4
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• pp.453-462
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• 2021

A lot of license plate data is required for car number recognition. License plate data needs to be balanced from past license plates to the latest license plates. However, it is difficult to obtain data from the actual past license plate to the latest ones. In order to solve this problem, a license plate recognition study through deep learning is being conducted by creating a synthetic license plates. Since the synthetic data have differences from real data, and various data augmentation techniques are used to solve these problems. Existing data augmentation simply used methods such as brightness, rotation, affine transformation, blur, and noise. In this paper, we apply a style transformation method that transforms synthetic data into real-world data styles with data augmentation methods. In addition, real license plate data are noisy when it is captured from a distance and under the dark environment. If we simply recognize characters with input data, chances of misrecognition are high. To improve character recognition, in this paper, we applied the DeblurGANv2 method as a quality improvement method for character recognition, increasing the accuracy of license plate recognition. The method of deep learning for license plate detection and license plate number recognition used YOLO-V5. To determine the performance of the synthetic license plate data, we construct a test set by collecting our own secured license plates. License plate detection without style conversion recorded 0.614 mAP. As a result of applying the style transformation, we confirm that the license plate detection performance was improved by recording 0.679mAP. In addition, the successul detection rate without image enhancement was 0.872, and the detection rate was 0.915 after image enhancement, confirming that the performance improved.

• Journal of the Korean Chemical Society
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• v.36 no.4
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• pp.540-545
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• 1992

Kinetics and mechanism on the solvent extraction of nickel(Ⅱ) with 8-hydroxyquinoline (HOx) was studied spectrophotometrically. Absorbance variation was measured by changing the 8-hydroxyquinoline concentration in the chloroform organic phase and the pH values in the aquous phase. By analyzing absorbance data the reaction rate was found to be the first order for 8-hydroxyquinoline concentration and the inverse first one for [H$^+$]. Therefore the rate determining step of the extraction reaction is the formation of the one-to-one metal chelate NiOx$^+$ and the rate equation is as follows; -d[Ni$^{2+}$]/dt = k[Ni$^{2+}$][Ox$^-$] = k'[Ni$^{2+}$][HOx]$_0$/[H$^+$]. The value of k' was evaluated from the slope of plot of log [Ni$^{2+}$]$_0$/[Ni$^{2+}$]$_t$ versus time and the rate constant k was calculated according to the equation k' = k ${\times}$ K$_{HOx}$ / K$_{D,HOx}$. From the temperature dependence of the extraction rate, the activation energy E$_a$ = 6.26 kcal/mol is calculated, and activation parameters, ${\Delta}$G$^{\neq}_{298}$ = 6.59 kcal/mol, ${\Delta}$H$^{\neq}_{298}$ = 5.68 kcal/mol, ${\Delta}$S$^{\neq}_{298}$ = -3.09 eu/mol are estimated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.3
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• pp.255-263
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• 2014

Today, a number of CCTV on the highway is to observe the flow of traffics. There have been a number of studies where traffic data (e.g., the speed of vehicles and the amount of traffic on the road) are transferred back to the centralized server so that an appropriate action can be taken. This paper introduces a system that detects the changes of traffic flows caused by an accident or unexpected stopping (i.e., vehicle remains idle) by monitoring each lane separately. The traffic flows of each lane are level spacing curve that shows Wigner distribution for location vector. Applying calogero-moser system and Hamiltonian system, probability equation for each level-spacing curve is derived. The high level of modification of the signal means that the lane is in accident situation. This is different from previous studies in that it does more than looking for the signal from only one lane, now it is able to detect an accident in entire flow of traffic. In process of monitoring traffic flow of each lane, when camera recognizes a shadow of vehicle as a vehicle, it will affect the accident detecting capability. To prevent this from happening, the study introduces how to get rid of such shadow. The system using Basian network method is being compared for capability evaluation of the system of the study. As a result, the system of the study appeared to be better in performance in detecting the modification of traffic flow caused by idle vehicle.

• Tuberculosis and Respiratory Diseases
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• v.44 no.4
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• pp.942-948
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• 1997

Benign Tracheobroncheal tumor is a rare disease such as 1.9% of all tumor of pulmonary origin. Because clinical manifestation of benign tracheal tumor resembles that of broncheal asthma, these patients are usually treated in a way that used in broncheal asthma. Therefore, the diagnosis is delayed. We experienced a case of tracheal neurilemmoma that cured by bronchoscopic laser therapy. A 23-year-old woman visited our hospital because of progressing dyspnea especially during inspiration. She was treated with aminophylline and 2 agonist under the impression of bronchial asthma at a local clinic. But because the symptoms were not relieved and pulmonary function test revealed variable extrathoracic lesion, we conducted bronchoscopy and biopsy. There were $1.5{\times}2cm$ sized movable mass with stalk attached right anterior wall of bronchus. The biopsy result was neurilemmoma. Therefore we conducted bronchoscopic Laser therapy four times and the lesion disappeared in bronchoscopy and chest CT.