• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.7
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• pp.92-101
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• 1993

This paper describes algorithms to extract license plates in vehicle images. Conventional methods perform preprocessing on the entire vehicle image to produce the edge image and binarize it. Hough transform is applied to the binary image to find horizontal and vertical lines, and the license plate area is extracted using the charateristics of license plates (the boundary information of license plates). Problems with this approach are that real-time processing is not feasible due to long processing time and that the license plate area is not extracted when lighting is irregular such as at night or when the plate boundary does not show up in the image. This research uses the gray level transition characteristics of license plates to verify the digit area by examining the digit width and the gray level difference between the background area the digit area, and then extracts the plate area by testing the distance between the verified digits. This research solves the probelm of failure in extracting the license plates due to degraded plate boundary as in the conventional methods and resolves the provlem of the time requirement by processing in real time such that practical application is possible.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.162-165
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• 2017

The proposed paper extracts the region of interest from the x-lay input image and compares it with the reference image. The x-ray image has the same shape, but the size, direction and position of the object are photographed differently. In this way, we measure the erection difference of darkness and darkness using the similarity measurement method for the same object. Distance measurement also calculates the distance between two points with vector coordinates (x, y, z) of x-lay data. Experimental results show that the proposed method improves the accuracy of ROI extraction and the reference image matching time is more efficient than the conventional method.

• The KIPS Transactions:PartB
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• v.10B no.1
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• pp.81-86
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• 2003

In this paper, we propose the tracking method of moving object which use extracted object by difference between background image and target image in fixed domain. As a extraction method of object, calculate not pixel of full image but predefined some edge pixel of image to get a position of new object. Since the center area Is excluded from calculation, the extraction time is efficiently reduced. To extract object in the predefined area, get a starting point in advance and then extract size of width and height of object. Central coordinate is used to track moved object.

• Journal of Korea Multimedia Society
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• v.10 no.2
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• pp.187-199
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• 2007

The purpose of painterly rendering is to express real painting work from input image. For expression of real pain ting impression, drawing condition is one of main element. In this paper, we propose new algorithm for using density of edges. Drawing condition of new algorithm uses color difference and density of edges. And for finding next position from current position, we used dynamic grid. We did direction interpolation for coherence direction. Also using various texture brush, we express the feel of a material effective. We show results of images rendered more realistic oil painting effect, and discuss long-term goals for more effective result.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.489-494
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• 2006

The strain distribution in the vicinity of a hole in a tensile strip was measured using an image correlation method. The objective of this study is to evaluate the capability of predicting the strain component response using a constitutive model that was developed for use with paper materials. The need for a special constitutive model for paper derives from the characteristics of pronounced anisotropy and the fact that the material behaves differently under compressive loading than it does under tensile loading. The results of the simulation showed that predictions of strain distribution around the hole were in agreement with the experimental result trends, however, the agreement deteriorated as the edge of the hole was reached. It was observed that there is extensive inelastic strain that takes place around the hole prior to failure of the tensile strip. The simulation results showed that any difference between tensile and compressive behavior that may exist for paper material does not have any significant effect for the problem of this study because the level of compressive stress is quite low in comparison with compressive failure values.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.136-142
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• 2008

The influence of different grids on numerical prediction of subsonic compressor performance and stall was investigated. Two types of grids were examined, structured H type grid and structured O-H type grid. Evaluations were conducted by comparing the numerical results with experimental results obtained from a low-speed single-stage rig test for a new concept compressor, called diffuser passage compressor, aiming at improving tip clearance sensitivity. At low mass flow operating conditions, the numerical calculation with O-H type grid showed that the lowest mass flow operating point for which the calculation was able to converge was almost the same as the lowest steady mass flow obtained from the rig test. On the other hand, the numerical calculation with structured H type grid diverged at higher mass flow operating point. It was found that this difference was attributed to the effect of double-valuedness of H type grid that existed at leading edge on the boundary layer development on the blade surface.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.1
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• pp.93-100
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• 2019

The cavitation of a turbopump inducer develops from the inception to a critical point, and encounters breakdown finally. In this study, we evaluated the characteristics and predictions of cavitation inception for the turbopump inducer using empirical equations. The empirical equation for the elliptical plate predicted the generation of cavitation inception of the turbopump inducer relatively well. However, in case of the marine propeller, it showed a considerable difference owing to the Reynolds number of the operating point. The cavitation inception occurred earlier as the number of blades increased. However, the solidity had no major impact on the cavitation inception because the cavitation occurred locally at the tip of the leading edge.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.11
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• pp.137-146
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• 2019

Recently, the Near-Surface-Mounting method using Fiber reinforced polymer (FRP) has been developed and applied to the reinforcement of many concrete structural members. However, as a part of the fire resistance design, there is a lack of research related to fire insulation for the areas reinforced with FRP. In case of NSM reinforcement, there is a difference in the transferred temperature from the external surface to the groove corresponding to the location of the groove where the FRP is embedded, and the effect of this should be reflected in the fireproof insulation design. Therefore, in this study, after forming grooves for surface embedding in concrete blocks, fireproof insulation reinforcement was performed using Calcium Silicate (CS) fireproof board and an experiment to evaluate the temperature transfer was performed. By observing the temperature at these groove positions, the reduction of temperature transfer according to fireproof insulation detail was studied. As a result, when the NSM-FRP is properly fire-insulated using the CS-based fireproof board, the epoxy inside the groove does not reach its glass transition temperature until the external temperature reaches $800^{\circ}C$.

• Current Applied Physics
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• v.18 no.11
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• pp.1225-1229
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• 2018

In this paper, we investigated the electronic structures and defect states of $SrLaMgTaO_6$ (SLMTO) double perovskite structures by using resonant inelastic x-ray scattering. Recently, $Eu^{3+}$ doped SLMTO red phosphors have been vigorously investigated due to their higher red emission efficiency compared to commercial white light emitting diodes (W-LED). However, a comprehensive understanding on the electronic structures and defect states of host SLMTO compounds, which are specifically related to the W-LED and photoluminescence (PL), is far from complete. Here, we found that the PL spectra of SLMTO powder compounds sintered at a higher temperature, $1400^{\circ}C$, were weaker in the blue emission regions (at around 400 nm) and became enhanced in near infrared (NIR) regions compared to those sintered at $1200^{\circ}C$. To elucidate the difference of the PL spectra, we performed resonant inelastic x-ray spectroscopy (RIXS) at Ta L-edge. Our RIXS result implies that the microscopic origin of different PL spectra is not relevant to the Ta-related defects and oxygen vacancies.

• Journal of Korean Neurosurgical Society
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• v.65 no.4
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• pp.591-597
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• 2022

Objective : Pituitary adenomas frequently extend into the suprasellar space. After a suprasellar tumor is removed, the superiorly extended arachnoid becomes redundant and sinks down into the intrasellar space which often hiders visualization and accessibility to the hidden space behind the evaginated arachnoid. We introduced arachnoid remodeling by clipping technique, and evaluated its usefulness and safety during TSS. Methods : Total 223 patients who underwent arachnoid remodeling with our new clipping technique were included. Redundant arachnoid was clipped along the dural edge with multiple 2.6-mm titanium clips until the redundant arachnoid membrane no longer blocked the surgical route. To check for possible deterioration of hormonal function by this technique, we assessed anterior pituitary function of 166 patients who underwent arachnoid remodeling by clipping and compared this with those of other 429 control patients. Results : Our technique greatly enhanced the accessibility and visualization of intrasellar and parasellar spaces, both of which are generally hindered by redundant arachnoid during transsphenoidal surgery (TSS). We found no difference in anterior pituitary function between a clip-assisted arachnoid remodeling group and the control group, implying that this technique does not result in hypopituitarism. Conclusion : During TSS for pituitary adenomas with suprasellar extension, arachnoid remodeling by clipping technique is very useful and convenient for the management of the redundant arachnoid membrane to enhance visualization and surgical accessibility.