• Journal of the Korea Institute of Building Construction
• /
• v.17 no.6
• /
• pp.545-557
• /
• 2017

The study is about the efficient alternative to concrete surface in the field of visual inspection technology for deteriorated infrastructure. By combining industrial drones and deep learning based image analysis techniques with traditional visual inspection and research, we tried to reduce manpowers, time requirements and costs, and to overcome the height and dome structures. On board device mounted on drones is consisting of a high resolution camera for detecting cracks of more than 0.3 mm, a lidar sensor and a embeded image processor module. It was mounted on an industrial drones, took sample images of damage from the site specimen through automatic flight navigation. In addition, the damege parts of the site specimen was used to measure not only the width and length of cracks but white rust also, and tried up compare them with the final image analysis detected results. Using the image analysis techniques, the damages of 54ea sample images were analyzed by the segmentation - feature extraction - decision making process, and extracted the analysis parameters using supervised mode of the deep learning platform. The image analysis of newly added non-supervised 60ea image samples was performed based on the extracted parameters. The result presented in 90.5 % of the damage detection rate.

• Journal of Pharmaceutical Investigation
• /
• v.36 no.5
• /
• pp.331-338
• /
• 2006

A rapid, selective and sensitive reverse-phase HPLC methods for the determination of atenolol and chlorthalidone in human serum and whole blood were validated, and applied to the pharmacokinetic study of atenolol and chlorthalidone combination therapy. Atenolol and an internal standard, pindolol, were extracted from human serum by liquid-liquid extraction, and analyzed on a $\mu$-Bondapak C18 $10-{\mu}$ column in a mobile phase of methanol-0.01 M potassium dihydrogenphosphate(30:70, v/v, adjusted to pH 3.5) and fluorescence detection(emission: 300 nm, excitation: 224 nm). Chlorthalidone and an internal standard, probenecid, were extracted form human whole blood by liquid-liquid extraction, and analyzed on a Luna C18 $5-{\mu}$ column in a mobile phase of acetonitrile containing 77% 0.01 M sodium acetate and UV detection at 214 nm. These analysis were performed at three different laboratories using the same quality control(QC) samples. The chromatograms showed good resolution, sensitivity, and no interference by human serum and whole blood, respectively. The methods showed linear responses over a concentration range of 10-1,000 ng/mL for atenolol and 0.05-20 ${\mu}g/mL$ for chlorthalidone, with correlation coefficients of greater than 0.999 at all the three laboratories. Intra- and inter-day assay precision and accuracy fulfilled international requirements. Stability studies(freeze-thaw, short-, long-term, extracted sample and stock solution) showed that atenolol and chlorthalidone were stable. The lower limit of quantitation of atenolol and chlorthalidone were 10 ng/mL and 0.05 ${\mu}g/mL$, respectively, which was sensitive enough for pharmacokinetic studies. These methods were applied to the pharmacokinetic study of atenolol and chlorthalidone in human volunteers following a single oral administration of Hyundai $Tenoretic^{\circledR}$ tablet(atenolol 50 mg and chlorthalidone 12.5 mg) at three different laboratories.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.35 no.10
• /
• pp.948-956
• /
• 2007

It is important during FSD(Full Scale Development) period to verify whether the aircraft system function meets the aircraft requirements and functional performance. Especially, the functionality of the integrated propulsion system should be verified to evaluate the compatibility with aircraft. Various flight tests such as the engine airstart test, the engine horsepower extraction test, the backup throttle functionality test had been performed to evaluate the engine/aircraft compatibility with T-50 during FSD period. Through such flight tests, it was confirmed that the propulsion system of T-50 was properly designed and installed to the aircraft. This paper shows description on each flight test item, test procedure and test results. It is expected that this paper could be a reference for preparing the propulsion flight test in other aircraft developments.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 1999.11a
• /
• pp.194-204
• /
• 1999

The use of genetically cloned xylanase acquired from Bacillus strearthermophillus improves bleachability for oak kraft pulps. Combination of xylanase(X). oxygen(O), ozone(Z). peroxide(P), alkaline extraction(Eo. Eop), and chlorination(C/D, D) have been tested in a variety of bleaching sequences. The effectiveness of xylanase pre-treatment(XO) and post-treatment(OX) in oxygen bleaching is mainly compared. With xylanase treatment the brightness increase by 1.5-2.1% ISO in OZEP, OZEoP, OZEopP and OPZP sequences. There is only numerically difference of brightness gains between OX and XO sequences. With xylanase treatment chemical requirements for bleaching decrease by 42.6-48.6% in OC/DEoD sequence and 47.9-54.7% as active chlorine in OC/DEopD sequence at the same brightness. the reduction of bleaching chemicals is higher in XO sequence than those in OX sequence. Following xylanase treatment the viscosity increases from 11.7-12.0 mPa·s to 12.4-13.5 mPa·s and the brightness stability is considerably improved however the difference of effectiveness between XO and OX sequence is not present. Compared to tensile index vs tear index, the physical properties are similar for TCF bleaching sequences with and without xylanase treatments. However in OC/DEoD and OC/DEopD sequences the physical properties decrease with xylanase treatment. There is no difference in the physical properties between XO and OX sequences. COD, BOD and color of bleaching effluents increase slightly with xylanase treatment, however the discharge of COD end-load into environmental impact decrease.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.4
• /
• pp.2124-2148
• /
• 2017

Accurate facial expression recognition (FER) requires reliable signal filtering and the effective feature extraction. Considering these requirements, this paper presents a novel approach for FER which is robust to noise. The main contributions of this work are: First, to preserve texture details in facial expression images and remove image noise, we improved the anisotropic diffusion filter by adjusting the diffusion coefficient according to two factors, namely, the gray value difference between the object and the background and the gradient magnitude of object. The improved filter can effectively distinguish facial muscle deformation and facial noise in face images. Second, to further improve robustness, we propose a new feature descriptor based on a combination of the Histogram of Oriented Gradients with the Canny operator (Canny-HOG) which can represent the precise deformation of eyes, eyebrows and lips for FER. Third, Canny-HOG's block and cell sizes are adjusted to reduce feature dimensionality and make the classifier less prone to overfitting. Our method was tested on images from the JAFFE and CK databases. Experimental results in L-O-Sam-O and L-O-Sub-O modes demonstrated the effectiveness of the proposed method. Meanwhile, the recognition rate of this method is not significantly affected in the presence of Gaussian noise and salt-and-pepper noise conditions.

• Journal of the Korea Convergence Society
• /
• v.8 no.11
• /
• pp.77-83
• /
• 2017

For efficient predictive analysis, self-healing research is needed that enables the system to recover autonomously by self-cognition and diagnosing system problems. However, software development does not provide formal contextual information analysis and appropriate presentation structure according to external situation. In this paper, we propose a prediction analysis method based on the change contents by applying the extraction rule to the functions that can act, data, and transaction based on the new Goal-scenario. We also evaluated how well the predictive analysis met through the performance indicators for achieving the requirements goal. Compared with the existing methods, the proposed method has a maximum 32.8% higher matching result through performance measurement, resulting in a 28.9% error rate and a 45.8% reduction in the change code. This shows that it can be processed into a serviceable form through rules, and it shows that performance can be expanded through predictive analysis of changes.

• Journal of the Microelectronics and Packaging Society
• /
• v.21 no.1
• /
• pp.19-23
• /
• 2014

For the application of light-emitting diodes (LEDs) for general illumination, the development of high power LEDs chips became more essential. For these reasons, recently, modified vertical LEDs have been developed to meet various requirements such as better heat dissipation, higher light extraction and less cost of production. In this research, we investigate the effect of Size and Array of N-GaN contact on operation voltage with new structured padless vertical LED. We changed the size and array of N-electrodes and investigated how they affect the operation voltage of LEDs. We simulated the current crowding and expected operation voltage for different N-contact structures with commercial LED simulator. Also, we fabricated the padless vertical LED chips and measured the electrical property. From the simulation, we could know that the larger size and denser array of n-electrodes could make operation voltage decrease. These results are well in accordance with those measured values of real padless vertical LED chips.

• Nuclear Engineering and Technology
• /
• v.36 no.4
• /
• pp.357-363
• /
• 2004

A prototype long pulse ion source was developed, and the beam extraction experiments of the ion source were carried out at the Neutral Beam Test Stand (NBTS) of the Korea Superconducting Tokamak Advanced Research (KSTAR). The ion source consists of a magnetic bucket plasma generator, with multi-pole cusp fields, and a set of tetrode accelerators with circular apertures. Design requirements for the ion source were a 120kV/65A deuterium beam and a 300 s pulse length. Arc discharges of the plasma generator were controlled by using the emission-limited mode, in turn controlled by the applied heating voltage of the cathode filaments. Stable and efficient arc plasmas with a maximum arc power of 100 kW were produced using the constant power mode operation of an arc power supply. A maximum ion density of $8.3{\times}10^{11}\;cm^{-3}$ was obtained by using electrostatic probes, and an optimum arc efficiency of 0.46 A/kW was estimated. The accelerating and decelerating voltages were applied repeatedly, using the re-triggering mode operation of the high voltage switches during a beam pulse, when beam disruptions occurred. The decelerating voltage was always applied prior to the accelerating voltage, to suppress effectively the back-streaming electrons produced at the time of an initial beam formation, by the pre-programmed fast-switch control system. A maximum beam power of 0.9 MW (i.e. $70\;kV{\times}12.5\;A$) with hydrogen was measured for a pulse duration of 0.8 s. Optimum beam perveance, deduced from the ratio of the gradient grid current to the total beam current, was $0.7\;{\mu}perv$. Stable beams for a long pulse duration of $5{\sim}10\;s$ were tested at low accelerating voltages.

• Korean Journal of Computational Design and Engineering
• /
• v.10 no.6
• /
• pp.444-454
• /
• 2005

Recently, the requirements of multi-resolution models of a solid model, which represent an object at multiple levels of feature detail, are increasing for engineering tasks such as analysis, network-based collaborative design, and virtual prototyping and manufacturing. The research on this area has focused on several topics: topological frameworks for representing multi-resolution solid models, criteria for the level of detail (LOD), and generation of valid models after rearrangement of features. As a solution to the feature rearrangement problem, the new concept of the effective zone of a feature is introduced in the former part of the paper. In this paper, we propose a feature-based non-manifold modeling system to provide multi-resolution models of a feature-based solid or non-manifold model on the basis of the effective feature zones. To facilitate the implementation, we introduce the class of the multi-resolution feature whose attributes contain all necessary information to build a multi-resolution solid model and extract LOD models from it. In addition, two methods are introduced to accelerate the extraction of LOD models from the multi-resolution modeling database: the one is using an NMT model, known as a merged set, to represent multi-resolution models, and the other is storing differences between adjacent LOD models to accelerate the transition to the other LOD. We also suggest the volume of the feature, regardless of feature type, as a criterion for the LOD. This criterion can be used in a wide range of applications, since there is no distinction between additive and subtractive features unlike the previous method.

• International Journal of Internet, Broadcasting and Communication
• /
• v.7 no.1
• /
• pp.15-19
• /
• 2015

The depth information of an image is used in a variety of applications including 2D/3D conversion, multi-view extraction, modeling, depth keying, etc. There are various methods to acquire depth information, such as the method to use a stereo camera, the method to use the depth camera of flight time (TOF) method, the method to use 3D modeling software, the method to use 3D scanner and the method to use a structured light just like Microsoft's Kinect. In particular, the depth camera of TOF method measures the distance using infrared light, whereas TOF sensor depends on the sensitivity of optical light of an image sensor (CCD/CMOS). Thus, it is mandatory for the existing image sensors to get an infrared light image by bundling several pixels; these requirements generate a phenomenon to reduce the resolution of an image. This thesis proposed a measure to acquire a high-resolution image through gradual area movement while acquiring a low-resolution image through pixel bundling method. From this measure, one can obtain an effect of acquiring image information in which illumination intensity (lux) and resolution were improved without increasing the performance of an image sensor since the image resolution is not improved as resolving a low-illumination intensity (lux) in accordance with the gradual pixel bundling algorithm.