• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.3
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• pp.26-33
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• 2014

The gas-centerd swirl injectors are widely used on the main combustor of large liquid propellant rocket engines. Since the gas-liquid propellants, such as kerosene and oxygen-rich gas combination, are mixed and burned in the high pressure condition over the critical pressure point, the cold-flow spray test in the atmospheric condition can not represent the actual spray pattern. To observe the near actual spray patterns of gas-centered swirl injector, the high pressure spray chamber and the control system were constructed. The operating sequence was controlled precisely to obtain clear visualization images.

• IEMEK Journal of Embedded Systems and Applications
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• v.9 no.3
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• pp.145-150
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• 2014

This paper presents an effective vision based method for LED traffic light detection at the daytime. First, the proposed method calculates horizontal coordinates to set region of interest (ROI) on input sequence images. Second, the proposed uses color segmentation method to extract region of green and red traffic light. Next, to classify traffic light and another noise, shape filter and haar-like feature value are used. Finally, temporal delay filter with weight is applied to remove blinking effect of LED traffic light, and state and weight of traffic light detection are used to classify types of traffic light. For simulations, the proposed method is implemented through Intel Core CPU with 2.80 GHz and 4 GB RAM, and tested on the urban and rural road video. Average detection rate of traffic light is 94.50 % and average recognition rate of traffic type is 90.24 %. Average computing time of the proposed method is 11 ms.

• Publications of The Korean Astronomical Society
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• v.32 no.3
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• pp.421-438
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• 2017

Through the short-period variability survey program, we obtained time-series BV CCD images for $1.5^{\circ}{\times}1.0^{\circ}$ region around the young open cluster NGC 457. As a result, we have detected 61 variable stars including 31 new ones after checking light curves of all stars by eyes. The 61 variable stars were included 14 ${\delta}$ Scuti variable stars, a ${\beta}$ Cephei variable star, 10 variable Be and slowly pulsating B stars, 13 eclipsing binary stars, 21 semi-long periodic or slow irregular variables and an RR Lyrae variable star, respectively. Many variable B-type stars were known through a well-defined zero-age main sequence to the ${\beta}$ Cepheid region of NGC 457. Most of the variable B-type stars found this paper were known variable stars. But, 11 out of 14 ${\delta}$ Scuti variable stars were newly discovered. The new variable stars except for ${\delta}$ Scuti stars were 4 variable B-type stars, 5 eclipsing binaries and 11 semi-long periodic or slow irregular variables. We have performed frequency analysis for all ${\delta}$ Scuti stars, a ${\beta}$ Cepheid star and an RR Lyrae star.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.143-143
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• 2008

Nanowires are promising options for building nanoscale electronic structures coming from high conductivity of nanowires. In particular, Deoxyribonucleic acid (DNA), which is structurally nanowire, can obtain highly ordered electronic components for nanocircuitry and/or nanodevices because of its very flexible length controllability, nanometer-size diameter, about 2 nm, and self-assembling properties. In this work, we used the method to form DNA-Nanowires (NWs) by using chemical treatment on Silicon (Si) surface, and Aminopropyl-triethoxysilane (APTES) was used as inducer of DNA sequence to modify the characteristics of Si surface. Moreover, we performed tilting technique to align DNA by the direction of flow of DNA solution. We investigated the assembly process between DNA molecules and APTES - coated Si surface according to the APTES concentration, from $1.2{\mu}\ell$ to $120{\mu}\ell$. Atomic Force Microscopy (AFM) images showed the combination rate of DNA molecules by the change of APTES concentration. As APTES concentration becomes thicker, aggregation of DNA molecules occurs, and this makes a kind of DNA networks. In this respect, we confirmed that there's a positive relationship between the concentration of APTES and the formation rate of DNA nanowires. Since there have been lots of research preceded to utilize DNA nanowires as template, so by using this positive relationship with proper alignment technique, realization of nano electronic devices with DNA nanowires might be feasible.

• Genomics & Informatics
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• v.12 no.4
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• pp.289-292
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• 2014

Next-generation sequencing (NGS) is widely used to identify the causative mutations underlying diverse human diseases, including cancers, which can be useful for discovering the diagnostic and therapeutic targets. Currently, a number of single-nucleotide variant (SNV)-calling algorithms are available; however, there is no tool for visualizing the recurrent and phenotype-specific mutations for general researchers. In this study, in order to support defining the recurrent mutations or phenotype-specific mutations from NGS data of a group of cancers with diverse phenotypes, we aimed to develop a user-friendly tool, named mutation arranger for defining phenotype-related SNV (MAP). MAP is a user-friendly program with multiple functions that supports the determination of recurrent or phenotype-specific mutations and provides graphic illustration images to the users. Its operation environment, the Microsoft Windows environment, enables more researchers who cannot operate Linux to define clinically meaningful mutations with NGS data from cancer cohorts.

• Proceedings of the KSMRM Conference
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• 2002.11a
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• pp.78-78
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• 2002

Purpose： The purpose of this study is to describe a distributed circuit approach to high frequency volume coil design illustrated with specific coils built accordingly and results obtained from animal studies at 3.0 tesla. Method： All experiments were conducted on 3T MRI system (Medinus Co., Ltd. Korea). The tuned TEM resonator measures 15cm outer diameter. by 10cm inside diameter by 30cm in length. The inside diameter and length were determined by animals body or head size (eg. rats or small dogs, etc.) while the outer diameter was chosen for compactness with some sacrifice of the optimal coil Q predicted for a larger cavity. A spin echo sequence with a TR/TE/flip angle=500/12.4ms/$75^{\circ}$was used to check image qualities with phantom. The breed of rat which used for animal images was Sprague-dawley(SD) and was anesthetic using ketamin hydrochloride 75mg/kg.

• Journal of the Semiconductor & Display Technology
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• v.12 no.2
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• pp.27-32
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• 2013

Shape From Focus (SFF) is a passive optical technique to recover 3D structure of an object that utilizes focus information from 2D images of the object taken at different focus levels. Mostly, SFF methods use a single focus measure to compute image focus quality of each pixel in the image sequence. However, it is difficult to recover accurate 3D shape using a single focus measure, as different focus measures perform differently in diverse conditions. In this paper, a nonlinear Total Variation (TV) based approach is proposed for 3D shape recovery. To improve the result of surface reconstruction, several initial depth maps are obtained using different focus measures and the resultant 3D shape is obtained by diffusing them through TV. The proposed method is tested and evaluated by using image sequences of synthetic and real objects. The results and comparative analysis demonstrate the effectiveness of our method.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.38 no.6
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• pp.46-56
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• 2001

In this paper we propose an efficient approach for real-time eye-gaze tracking from image sequence and magnetic sensory information. The inputs to the eye-gaze tracking system are images taken by a camera and data from a magnetic sensor. The measuring data are sufficient to describe the eye and head movement, because the camera and the receiver of a magnetic sensor are stationary with respect to the head. Experimental result shows the validity of real time application aspect of the proposed system and also shows the feasibility of the system as using a new computer interface instead of the mouse.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.85.2-85.2
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• 2012

The interstellar medium (ISM) of galaxies in the galaxy cluster can well be affected by the intracluster medium (ICM). Among many suggested environmental processes, ram pressure stripping can effectively remove gas through the interaction with the ICM. In fact, Cluster galaxies are lower in HI gas mass compared to their field counterparts, and in recent high resolution HI imaging studies, many galaxies in dense environments have been found to be ram pressure stripped in HI. However, it is still under debate whether the ICM pressure can also remove dense molecular gas from the galactic disk, which plays more important role in star formation and hence galaxy evolution. To answer this question, we have obtained high resolution 12/13 CO (2-1) data from the Sub Millimeter Array (SMA) of four galaxies at various HI stripping stages to study how the molecular gas properties change as the galaxy experiences the ICM pressure. We investigate the physical properties of molecular gas with 12/13 CO images. By comparing with other wavelength data, i.e. data(optical, HI, $H{\alpha}$, etc), we discuss how and in which timescale galaxies can migrate from the blue cloud to the red sequence due to ram pressure stripping.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1C
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• pp.62-67
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• 2008

In this paper, wavelet based blind watermarking using self-reference method is proposed. First, we process wavelet transform of original image. Then, we set all domain except for the low-frequency domain to zero and make self-reference image after wavelet reverse transformation. By choosing specific domain according to the pixel value difference between original image and self-reference image, we make random sequence, use as watermark and embed. The experimental results of the watermark embedding and extraction on various images show that the proposed scheme not only has good image quality, but also has stability on JPEG lossy compression, filtering, sharpening, blurring and noise.