• The Journal of Engineering Geology
• /
• v.7 no.2
• /
• pp.101-112
• /
• 1997

Gravity and electrical resistivity surveys were carried out across the Kwangju fault in the downstream area of the Jangsung Lake, to investigate the location and geometrical feature of the fault. In the resistivity survey, dipole - dipole array method was adopted for 3 survey lines of which length and electrode spacing are 500m and 25m, respectively. Resistivity data are interpreted with aid of computer program "RESIS" which is widely used in resistivity data analysis and two dimensional resistivity profiles are obtained for 3 survey lines. Two large fracture zones relevant to the Kwangju fault are identified in the resistivity profiles. The total of 80 gravity data are observed with the mean spacing of 40 m and the exact leveling is accompanied to obtain more precise gravity anomalies. The subterranean density discontinuities calculated from the inverse method are appeared at the depths of 650rn and 120m. It is considered that the deep discontinuity indicates boundary between Jurassic granites and oveflying Cretaceous tuff formation. while, the shallow discontinuity is interpreted to be a boundary between alluvial deposits and basements. The subsurface geological structure to satisfy the observed Bouguer anomaly is determined from the iterative forward method in which results from existing surface geological informations, the inverse method, and from the resistivity interpretations are employed as an iuitial model. In conclusion, Kwangju fault is appeared to be a high angle normal fault mainly formed in tension stress filed.

• Journal of the Korean earth science society
• /
• v.33 no.7
• /
• pp.608-617
• /
• 2012

The symbiotic nova Z Andromedae (And) was investigated, using the high dispersion spectra of spectral resolution, ${\Delta}{\lambda}{\sim}-0.1{\AA}$. The spectral observations were done with (1) the Hamilton Echelle Spectrograph (HES) and the high resolution spectra (exposures=1800s and 3600s) were obtained at Lick Observatory in 2001 August $30^{th}$ (phase ${\Phi}$=0.77), and 2002 August $12^{th}$ (phase ${\Phi}$=0.22), (2) with the Bohyunsan Echelle Spectrograph (BOES) at Bohyunsan Optical Astronomy Observatory and the high resolution spectra (exposure=1200s) were secured in 2009 October $21^{st}$ (phase ${\Phi}$=0.70). From both the HES and BOES spectral data in the $3600{\AA}-9500{\AA}$ wavelengths, we extracted the emission lines of HI, HeI, and HeII, which have been decomposed into double or triple Gaussian components for 3 consecutive phases. The emission zones responsible for these components appear to be closely related with the orbital motion of a white dwarf or a giant star. The presence of the Raman scattering $H{\alpha}$ broad wing feature and the kinematic characteristics of the line profile observed in each phase imply that the Z And emission lines are mostly from two Lagrangian points, $L_1$ and $L_2$, and the accretion disk around the white dwarf star. The Z And was most active in 2009 and 2001 during the outburst phase, while it remained quiescent in 2002 in spite of the complex line profiles.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2011.05a
• /
• pp.185-185
• /
• 2011

Mapping of artificial levee lines, one of major tasks in river zone mapping, is critical to prevention of river flood, protection of environments and eco systems in river zones. Thus, mapping of artificial levee lines is essential for management and development of river zones. Coastal mapping including river zone mapping has been historically carried out using surveying technologies. Photogrammetry, one of the surveying technologies, is recently used technology for national river zone mapping in Korea. Airborne laser scanning has been used in most advanced countries for coastal mapping due to its ability to penetrate shallow water and its high vertical accuracy. Due to these advantages, use of LiDAR data in coastal mapping is efficient for monitoring and predicting significant topographic change in river zones. This paper introduces a method for construction of a 3D artificial levee line using a set of LiDAR points that uses normal vectors. Multiple steps are involved in this method. First, a 2.5-dimensional Delaunay triangle mesh is generated based on three nearest-neighbor points in the LiDAR data. Second, a median filtering is applied to minimize noise. Third, edge selection algorithms are applied to extract break edges from a Delaunay triangle mesh using two normal vectors. In this research, two methods for edge selection algorithms using hypothesis testing are used to extract break edges. Fourth, intersection edges which are extracted using both methods at the same range are selected as the intersection edge group. Fifth, among intersection edge group, some linear feature edges which are not suitable to compose a levee line are removed as much as possible considering vertical distance, slope and connectivity of an edge. Sixth, with all line segments which are suitable to constitute a levee line, one river levee line segment is connected to another river levee line segment with the end points of both river levee line segments located nearest horizontally and vertically to each other. After linkage of all the river levee line segments, the initial river levee line is generated. Since the initial river levee line consists of the LiDAR points, the pattern of the initial river levee line is being zigzag along the river levee. Thus, for the last step, a algorithm for smoothing the initial river levee line is applied to fit the initial river levee line into the reference line, and the final 3D river levee line is constructed. After the algorithm is completed, the proposed algorithm is applied to construct the 3D river levee line in Zng-San levee nearby Ham-Ahn Bo in Nak-Dong river. Statistical results show that the constructed river levee line generated using a proposed method has high accuracy in comparison to the ground truth. This paper shows that use of LiDAR data for construction of the 3D river levee line for river zone mapping is useful and efficient; and, as a result, it can be replaced with ground surveying method for construction of the 3D river levee line.

• Conservation Science in Museum
• /
• v.20
• /
• pp.13-30
• /
• 2018

Ancient metal objects with inlaid designs were mainly decorated using the wire inlay technique in which "V"- or "U"-shaped grooves were cut in a metal object and then filled with gold or silver. Previous studies on ancient metal objects featuring wire inlay generally attempted to ascertain the inlay techniques applied by examining photomicroscopes acquired during conservation treatment. However, they had limitations when examining wire inlay technique to the minute details. Wire inlay technique can be better investigated by enlarging X-ray films of relics using stereoscopic microscopy under transmitted light. The core processes of the wire inlay technique involve cutting grooves using a chisel and creating the inlay wires, but researchers hold varying opinions about the two processes. This study analyzed the entirety of the materials able to shed light on the main processes applied in Baekje wire inlay by examining X-ray films of relics through stereoscopic microscopy. This exhaustive research revealed that two types of techniques were used for wire inlay during the Baekje period. One is a plastic process of engraving dotted lines using a chisel and is found mostly in objects from the Cheonan and Gongju areas. The other is a cutting process that incises fine lines and was used mostly in relics from the Osan, Seosan, and Wanju areas. It is likely that the Baekje wire inlay techniques feature regional differences because the respective techniques were used or introduced by different groups of people.

• Journal of Advanced Navigation Technology
• /
• v.22 no.6
• /
• pp.642-647
• /
• 2018

In this paper, an unequal power divider based on adjusting electrical length of uniform transmission line is presented. This divider consists of three uniform transmission lines and one isolation resistor and have the different port impedances of input and output. The feature of proposed divider can changed the power dividing ratio to adjust only electrical length of uniform transmission lines. To verify the feasibility of proposed power divider, two divider circuits are designed, one is 1:2 power dividing ratio divider with $60{\Omega}$ uniform transmission line and $40{\Omega}$ input port impedances and $45{\Omega}$ output port impedances, the performance data were measured the insertion losses of 1.7 dB/ 5.0 dB, return losses of more than -30 dB and isolation of more than -35 dB. The other is 1:4 power dividing ratio divider with $40{\Omega}$ uniform transmission line and $50{\Omega}$ input port impedances and $75{\Omega}$ output port impedances, the performance data were measured the insertion losses of 1.3 dB/ 6.8 dB, return losses of more than -12 dB and isolation of more than -19 dB. The measured performance data agreed well with the simulated results.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.66 no.1
• /
• pp.37-71
• /
• 2021

Rapeseed is a typical winter crop, and its freezing stress tolerance is a major feature for winter survival. Therefore, it is important to comprehend clearly the physical and molecular mechanisms of rapeseed under freezing stress conditions. This study investigates the physical and transcriptome changes of two rapeseed lines, 'J8634-B-30' and 'EMS26', under cold acclimation and freezing temperature treatments. The proline content of 'J8634-B-30' at 5 ℃ increased 8.7-fold compared to that before treatment, and there was no significant change in that of 'EMS26' RNA-sequencing analysis revealed 5,083 differentially expressed genes (DEGs) of 'J8634-B-30' under cold acclimation condition. Among the genes, 2,784 (54.8%) were up-regulated and 2,299 (45.2%) were down-regulated. The DEGs of 'EMS26' under cold acclimation condition were 5,831 genes, and contained 2,199 up-regulated genes (37.7%) and 3,632 down-regulated genes (62.3%). Among them, only DEGs annotated in the cold response-related signaling pathways were selected, and their expression in the two rapeseed lines was compared. Comparative DEGs analysis indicated that cold response related signaling pathways are proline metabolism and ABA (Abscisic acid) signaling. And ICE (Inducer of CBF expression) - CBF (C-repeat-binding factor) - COR (Cold-regulated) signaling were the significantly differentially expressed transcripts in the two rapeseed lines. The major induced transcripts of 'J8634-B-30' induced P5CS (Δ'-pyrroline-5-carboxylate synthetase), which is related to proline biosynthesis, PYL (pyrabactin resistance-like protein, ABA receptor) and COR413 (cold-regulated 413 plasma membrane 1). In conclusion, these result provide a foundation for understanding the mechanisms of freezing stress tolerance in rapeseeds. Further functional studies should be performed on the freezing stress-related genes identified in this study, which can contribute to the transgenic and molecular breeding for freezing stress tolerance in rapeseed.

• The Bulletin of The Korean Astronomical Society
• /
• v.38 no.2
• /
• pp.71.1-71.1
• /
• 2013

Among quadruples or higher multiplicity stars, only a few binary systems have been discovered. They are important targets to understand the formation and evolution of multiple stellar systems because we can obtain accurate stellar parameters from photometric and spectroscopic studies. We present the observational results of this kind of rare object 1SWASP J093010.78+533859.5, for which the doubly eclipsing feature had been detected previously from the SuperWASP photometric archive. Individual PSF photometry for two objects with a separation of about 1.9 arcsec was performed for the first time in this study. Our time-series photometric data show that the brighter object A is an Algol-type detached eclipsing binary with an orbital period of 1.3 days and the fainter B is a W UMa-type contact eclipsing binary with a period of 0.23 days. Using the high-resolution optical spectra, we obtained well-defined radial velocity variations of the system A. Furthermore, stationary spectral lines were detected and should have originated from the other stellar component, which was confirmed by the third object contribution from the light curve analysis. No spectral feature of the system B was detected, probably due to its faintness. We obtained the binary parameters and the absolute dimensions from each light curve synthesis. The primary and secondary components of the system A have a spectral type of K1 and K5 main sequences, respectively. Two components of system B have nearly the same type of K3 main sequence. Light variations at out of eclipses were appeared in both systems, interpreting as the effect of stellar spots on these late spectral type stars. We estimated the distances to the systems A and B individually. They may have similar distances of about 70 pc and seem to be gravitationally bound with a separation of about 130 AU. In conclusion, we suggest that 1SWASP J093010.78+533859.5 is a quintuple stellar system with a hierarchical structure of a triple system A(ab)c and a binary system B(ab).

• Journal of Broadcast Engineering
• /
• v.17 no.5
• /
• pp.838-850
• /
• 2012

In this paper, we propose a novel algorithm that generates multi-view images by using various image features obtained from the given stereoscopic images. In the proposed algorithm, we first create an intensity gradient saliency map from the given stereo images. And then we calculate a block-based optical flow that represents the relative movement(disparity) of each block with certain size between left and right images. And we also obtain the disparities of feature points that are extracted by SIFT(scale-invariant We then create a disparity saliency map by combining these extracted disparity features. Disparity saliency map is refined through the occlusion detection and removal of false disparities. Thirdly, we extract straight line segments in order to minimize the distortion of straight lines during the image warping. Finally, we generate multi-view images by grid mesh-based image warping algorithm. Extracted image features are used as constraints during grid mesh-based image warping. The experimental results show that the proposed algorithm performs better than the conventional DIBR algorithm in terms of visual quality.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.30 no.9
• /
• pp.558-565
• /
• 2017

Hybrid insulators that have the advantages of both porcelain (high mechanical strength and chemical stability) as well as polymer (light weight and high resistance to pollution) insulators, can be used in place of individual porcelain and polymer insulators that are used for both mechanical support as well as electrical insulation of overhead power transmission lines. The most significant feature of hybrid insulators is the presence of porcelain/polymer interfaces where the porcelain and polymer are physically bonded. Individual porcelain and polymer insulators do not have such porcelain/polymer interfaces. Although the interface is expected to affect the mechanical/electrical properties of the hybrid insulator, systematic studies of the adhesion properties at the porcelain/polymer interface and the effect of the interface on the insulation characteristics and electric field distribution of the hybrid insulator have not been reported. In this study, we fabricated small hybrid insulator specimens with various types of interfaces and investigated the effect of the porcelain/polymer interface on the microstructure, insulating characteristics, and electric field distribution of the hybrid insulators. It was observed that the porcelain/polymer interface of the hybrid insulator does not have a significant effect on the insulating characteristics and electric field distribution, and the hybrid insulator can exhibit electrical insulating properties that are similar or superior to those of individual porcelain and polymer insulators.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.43 no.3 s.309
• /
• pp.67-77
• /
• 2006

This thesis proposes an effi챠ent method for extracting a prostate volume from 3D ultrasound image by using wavelet transform and SVM classification. In the proposed method, a modulus image for each 2D slice is generated by averaging detail images of horizontal and vertical orientations at several scales, which has the sharpest local maxima and the lowest noise power compared to those of all single scales. Prostate contour vertices are determined accurately using a SVM classifier, where feature vectors are composed of intensity and texture moments investigated along radial lines. Experimental results show that the proposed method yields absolute mean distance of on average 1.89 pixels when the contours obtained manually by an expert are used as reference data.