• KIPS Transactions on Software and Data Engineering
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• v.9 no.2
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• pp.69-76
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• 2020

In this paper, we introduce a method to visualize the contrast diffusion patterns and the dynamic vascular patterns in a contrast-enhanced ultrasound image sequence. We present an imaging technique to visualize parameters such as contrast arrival time, peak intensity time, and contrast decay time in contrast-enhanced ultrasound data. The contrast flow pattern and its velocity are important for characterizing focal liver lesions. We propose a method for representing the contrast diffusion patterns as an image. In the methods, respiratory motion may degrade the accuracy of the parametric images. Therefore, we present a respiratory motion tracking technique that uses dynamic weights and a momentum factor with respect to the respiration cycle. Through the experiment using 72 CEUS data sets, we show that the proposed method makes it possible to overcome the limitation of analysis by the naked eye and improves the reliability of the parametric images by compensating for respiratory motion in contrast-enhanced ultrasonography.

• Journal of Korea Water Resources Association
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• v.45 no.12
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• pp.1227-1241
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• 2012

In this study, a novel water surface detection method was proposed. In the method water surface is detected by analysis on correlation coefficients obtained from rectangular control areas of the same vertical position in two successive images including both water surface and staff gauge. Four methods respectively based on threshold, peak, slope and variance ratio, are used to identify water surface from vertical distribution of correlation coefficient. In addition, swaying correction algorithm and statistical filtering are applied to minimize outliers caused by positional image mismatch. Images taken from 28 different sites during low flow were tested to evaluate the method. Mean relative error to eye measurement was approximately from 3.4 to 5.7 cm. As long as water surface moves, this method can be used to improve image stage gauge by supplementing the previous water surface detection method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.1
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• pp.89-99
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• 2014

This paper presents the experimental torque disturbance analysis of a missile hatch system by spline backlash. The missile hatch system uses a spline and gear train for vertical elevation of the heavy hatch. The spline used for the rotation shaft of the hatch is generally used for automotive driving parts that transmit high amounts of power. It has an angular backlash, which results in jerks. Backlash of the hatch spline influences hatch swinging. The spline backlash and hatch swing are experimentally analyzed by measuring the hatch's rotation angle and acceleration. Hatch swing is visually observable for a short period, and it is measured by measuring the rotation angle variation and hatch acceleration. The shape of fluctuation and duration time of hatch angle variation are similar to those of torque. This shows that the hatch swing due to spline backlash generates torque disturbances.

• Journal of Broadcast Engineering
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• v.18 no.6
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• pp.795-807
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• 2013

In recent years, 2D-to-3D conversion techniques have gained much attraction. Most of conventional methods focused on natural images such as movie, animation and so forth. However, it is difficult to apply these techniques to window images mixed with text, image, logo, and icon. Also, different depth values of text pixels will cause distortion and a proper 3D image can not be delivered in some situations. To solve this problem, we propose a method to classify a given image into either a window or a natural image. For the window image, only rectangular image regions (RIR) are detected and converted in 3D. Other text and background are displayed in 2D. The proposed method was performed on more than 10,000 test images. In the experimental results, the detection ratio of window image reaches 97% and RIR detection ratio is 87%.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.2
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• pp.59-66
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• 2014

AGV is most often used for the automation of freight transportation in the manufacturing industry or the distribution warehouses. AGV is fairly costly and used in goods transport between the determined location. The main control device dedicated to AGV is often autonomously developed for simplification using PLC in industry field. However, AGV developed for simplification makes many errors in traffic because it is developed for the limited simple function. Control device dedicated to AGV has been developed to solve the problem but it is almost impossible to revise the device according to the character and structure of every manufacturing industry. The purpose of this study is to propose the design method of the control system interlocked with PLC and dedicated to AGV. The control system should be to improve the problem of traffic rolling and possible to be revised according to the character of factory. It is apparent the proposed AGV system is efficient in operation in the result of several traffic performance analysis through the tests.

• Applied Microscopy
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• v.34 no.1
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• pp.51-59
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• 2004

The high acceleration voltage system used in scanning electron microscope were designed and manufactured to test its stability. The Cockcroft-Walton circuits are used both in the cathode voltage up to -30 kV and in the Wehnelt cylinder of -2 kV. The operating voltage of 6 V was applied to the heating of the filament. The wave forms which are formed in the second leg of the high voltage transformer were observed in the oscilloscope with 2 V of DC input. When the high voltages were in the range between 5 kV and 12 kV, the highest value of the stabilities of the generated voltages was obtained as 0.002%.

• Fire Science and Engineering
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• v.33 no.5
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• pp.140-148
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• 2019

In line with the "mandatory seismic design of fire protection facilities," development of design automation software is indispensable for improving the reliability and efficiency of seismic design. The seismic design automation software developed in this study is an automated S/W for seismic design of fire-fighting facilities, and functions such as automatic arrangement of anti-shake braces according to Korea National Fire Agency's Seismic Design Standards for fire-fighting facilities, output of seismic bracing calculation bills and automatic quantities counting. In addition, the seismic design automation software not only reduces the work speed by three times compared to the manual design of the designer, but also improves the reliability of the design by reducing the human error related to the design quantity such as the brace. In addition, in the seismic design method of fire protection facilities that have been approached conservatively, it was possible to perform the optimal seismic design by using computer algorithms for at least in the use of braces.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.1
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• pp.24-30
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• 2011

We have developed a hand-held probe for an ophthalmic OCT system. The hand-held probe for imaging was designed to be compact and portable. The cornea and retinal images were acquired by replacing the objective lens at the front of the probe. To verify the performance of the hand-held OCT probe, we acquired two dimensional OCT image of the rat eye in vivo and reconstructed three dimensional rat eye rendering images. In vivo 3D OCT images were showed distinct structural information in the posterior and anterior chamber with minimal motion artifacts. Thereby, OCT imaging speed is suitable for an dynamic in vivo experiment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.40-48
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• 2018

This paper proposes a license-plate recognition algorithm for automobile black-box image which is obtained from the camera moving with the automobile. The algorithm intends to increase the overall recognition-rate of the license-plate by increasing the Korean character recognition-rate using multi-stage neural network for automobile black-box image where there are many movements of the camera and variations of light intensity. The proposed algorithm separately recognizes the vowel and consonant of Korean characters of automobile license-plate. First, the first-stage neural network recognizes the vowels, and the recognized vowels are classified as vertical-vowels('ㅏ','ㅓ') and horizontal-vowels('ㅗ','ㅜ'). Then the consonant is classified by the second-stage neural networks for each vowel group. The simulation for automobile license-plate recognition is performed for the image obtained by a real black-box system, and the simulation results show the proposed algorithm provides the higher recognition-rate than the existing algorithms using a neural network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.6B
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• pp.859-866
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• 2010

Digital vessels can occur large a disaster at sea because vessels in fire and collision in case of certain unforeseen circumstances. In this paper, We propose digital vessel context monitoring system through risk analysis. We propose environment information analysis system using wireless sensor that have to acquire marine environment and context of marine digital vessel. For conducting simulation, we chose 300 data sets to train the neural network. As a result, we obtained about 96% accuracy for fire risk context and we obtained 88.7% accuracy for body of vessel risk context. To improve the accuracy of the system, we implement a FEC (Forward Error Correction) block. We implemented digital vessel context monitoring system that transmitted to diagnosis result in CDMA.