• 한국해양학회지
• /
• v.13 no.1
• /
• pp.1-8
• /
• 1978

A seismic reflection Survey was carried out in the offshere area between Geoje Island and Namhae Island, utilizing the echosounder with the frequency 28KHz and thd Uniboom with the filter band 800∼2000Hz. The results show the submarine topography, sedimentary layer structure and the depth distribution of the base rock. The water depth of the sea in the survey area is less than 80m; up to 40m contour line the sea bottom surface has a slight dip(about 1/1000), while in the zone deeper than 40m the bottom topography has a irregular relief. The thickness of the whole sedimentary deposit is about 20∼70m and divided into 3 layers: Upper layer(A layer) with horizontal laminae, intermediate layer(B layer) with cross-bedding and groove structure, and lower layer(C layer) not showing any sedimentary structure on the seismic reflection profile. The surface of the base rock is deeper gradually in the south-eastern part of the survey area and extends to 140m depth. The vertical sediments sequences, composed of B layer and A layer, show the type of transgressive sequences. It is interpreted that B layer was formed at one period when the sea level was lower 40∼60 than the present and ince then, following the rising of the sea level, A layer was deposited.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.12 no.3
• /
• pp.51-58
• /
• 1998

This paper deals with the power frequency electric and magnetic profiles from transformer and gas-insulated swichgear(GIS) perimeters in the indoor power substation. Measurements of electric and magnetic field magnitudes were carried out by using single axis and three axes field meters at a height of 1[m]. The resultant electric and magnetic field profiles measured in the vicinity of the transformer were displayed as a 2-dimensional plot. The electric fields intensity are relatively low value of about 2.3~9[V/m], and the magnetic fields intensity range from 0.3 to [$20.3\mu$T]. Also, in the GIS perimeter the electric fields intensity are in the range of 2.2~2.5[V/m], and the high magnetic fields are largely localized to the intermediate section of the GIS and their amplitudes are [$1.2~39.5\mu$T]. Metal enclosures of transform and GIS play a role in reducing the electric field, and the magnetic fields are characterized by a rapid decrease with distance from the transformer and GIS enclosures.

• Journal of Broadcast Engineering
• /
• v.15 no.4
• /
• pp.591-599
• /
• 2010

In this paper, we propose a disparity-adaptive filtering method to reduce view-aliasing and inter-perspective aliasing on auto-multiscopic 3D display. View aliasing by the subsampled multi-view images could happen if the resolution of an auto-multiscopic monitor is lower than that of the original multi-view images. Furthermore, multi-view images on auto-multiscopic monitor usually cause eye strain and fatigue because of inter-perspective aliasing by discontinuity that exists between viewpoints. The greater disparity value becomes, the stronger these types of aliasing could be. Thus, we design a lowpass filter whose cut-off frequency is determined adaptively to the number of intermediate reconstructed views and their disparity's strength. Though experimental results, we show that the proposed filtering algorithm could reduce the aliasing effect very efficiently by using DSCQS (double stimulus continuous quality scale method).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.13 no.3
• /
• pp.288-300
• /
• 2002

In this paper, a novel method of equalization of RF transceivers is suggested for MIMO(Multiple Input Multiple Output) antenna actively studied for high speed data transmission in the recent IMT-2000 system. The core of suggestion is in equalizing the transfer characteristics of multiple transceivers using feedback and memory during the predefined calibration time. This makes it possible to weight the signals in the intermediate frequency, which is easier in the application of recently developed DoA(Direction of Arrival) algorithms. In addition, the time varying optimum cell formation according to traffic is feasible by antenna beam-forming based on the DoA information. The suggested method of equalizing multiple transceivers are successfully verified using envelope simulation. two outputs. This paper is concerned with the diagnosis of multiple crosstalk-faults in OSM. As the network size becomes larger in these days, the convent.
nal diagnosis methods based on tests and simulation be.
me inefficient, or even more impractical. We propose a simple and easily implementable alg？ithm for detection and isolation of the multiple crosstalk-faults in OSM. Specifically, we develop an algorithm for isolation of the source fault in switc.
ng elements whenever the multiple crosstalk-faults are.
etected in OSM. The proposed algorithm is illustrated by an example of 16$\times$16 OSM.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.30 no.4
• /
• pp.45-61
• /
• 1988

The purpose of this study is to develop regression equations between annual specific sedi- ment of reservoirs and physiographic factors of watersheds. 122 irrigation reservoirs, which have irrigation areas equal to or larger than 200 ha, located in Korea except Cheju province are used in the analysis. Simple regression analyses between the specific annual sediment and each of the physical characteristic factors of the reservoirs are carried out at first. Then, multiple regression analyses between the annual specific sediment and the physical characteristic factors with high correlation coefficients in the simple regression analyses are made. The results obtained from this study are as follows : 1. The results of the sirnple regression analyses show that in each province the watershed area, the length of mainstream, the circumferential length of watershed have high cor- relation coefficients (R=0.814-0.986), and that drainage density, reservoir capacity per watershed area, drainage frequency, basin relief have low correlation coefficients (R=0. 387-0.955). 2. The purposed multiple regression equations between the annual specific sediment of reservoirs and three major characteritic factors of watersheds, namely, the watershed area, the circumferential length of watershed, and the length of mainstream, are proposed as given in Table 2. 3. The result of the simple regression analyses with respect to the reservoir elevation except Jeonnam province, which has very different characteristics comparing to other provinces, shows that watershed area, main stream length and circumferential length have high correlation coefficients (R=0.806-0.884) in low-elevation reservoirs and intermediate- elevation reservoirs, but low correlation coefficients (R=0.639-0.739) in high-elevation reservoirs. 4. With respect to the reservoir elevation, the proposed multiple regression equations bet- ween the annual specific sediment of reservoirs and the three major characteristic factors of watershed which have high correlation coefficients are proposed as given in Table 5.

• Journal of The Korean Astronomical Society
• /
• v.50 no.5
• /
• pp.151-155
• /
• 2017

We investigate the radio properties of the dwarf galaxy SDSS J133245.62+263449.3 which shows optical signatures of black hole activity. Dwarf galaxies are known to host intermediate mass black holes (IMBHs) with masses $M_{BH}{\sim}10^{4-6}M_{\odot}$, some of them being radio loud. Recently, Reines et al. (2013) found dwarf galaxy candidates which show signatures of being black hole hosts based on optical spectral lines. SDSS J133245.62+263449.3 is one of them; it shows a flux density of ~ 20 mJy at 1.4 GHz, which corresponds to $L_{1.4GHz}{\sim}10^{23}W\;Hz^{-1}$. This is much brighter than other black hole host dwarf galaxies. However, star formation activity can contribute to radio continuum emission as well. To understand the nature of the radio emission from SDSS J133245.62+263449.3, we imaged this radio loud dwarf galaxy at low frequencies (325 MHz and 610 MHz) using the Giant Metrewave Radio Telescope (GMRT). We present here the high resolution images from our GMRT observations. While we detect no obvious extended emission from radio jets from the central AGN, we do find the emission to be moderately extended and unlikely to be dominated by disk star formation. VLBI observations using the Korean VLBI Network (KVN) are now being planned to understand the emission morphology and radiation mechanism.

• Nuclear Engineering and Technology
• /
• v.5 no.4
• /
• pp.265-278
• /
• 1973

The incoherent neutron scattering cross section of molecular liquids is analyzed using a damping function model for correlation functions of molecular translations and rotations. The present approach is different from recent works in that the scattering function is evaluated directly, not through the intermediate scattering function. The damping fuction is determined from a simple relation between its long-wavelength limit and the generalized frequency distribution function, and translation-rotation couplings are assumed to be neglected. A physical model is used for the translational motions of center-of-mass of a molecule, including properly its short-time and long-time behaviors. A simple model for the rotational motions is suggested which relates the damping function to the Fourier transform of the dipole correlation function, or equivalently, the infrared vibrational absorption spectrum. Theoretical absolute scattering intensities are computed for liquid methane and shown to be in satisfactory agreement with both thermal and cold neutron measurements.

• Journal of Microbiology
• /
• v.38 no.2
• /
• pp.80-87
• /
• 2000

The nucleotide sequence of the luxC gene coding for lux-specific fatty acyl-CoA reductase and the upstream DNA (325bp)of the structural gene from bioluminescent bacterium, Photobacterium phosphoreum, has been deternubed. An open reading frame extending for more than 20 codons in 325 bp DNA upstream of luxC was not present in both directions. The lux gene can be translated into a polypeptide of 54 kDa and the amino acid sequences of lux specific reductases of P. phosphoreum shares 80, 65, 58, and 62% identity with those of the Photobacterium leiognathi, Vibrio fischeri, Vibrio harveyi, and Xehnorhabdus luminescenens reductases, respectively. Analyses of codon usage, showing that a high frequency (2.3%) of the isoleucine codon, AUA, in the luxC gene compared to that found in Escherichia coli genes (0.2%) and its absence in the luxA and B genes, suggested that the AUA codon may play a modulator role in the expression of lux gene in E. coli. The structural genes (luxC, D, A, B, E) of the P. phosphoreum coding for luciferase (${\alpha}$,${\beta}$) and fatty acid reductase (r, s, t) polypeptides can be expressed exclusively in E. coli under the T7 phage RNA polymerase/promoter system and identificationof the [35S]methionine labelled polypeptide products. The degree of expression of lux genes in analyses of codon usage. High expression of the luxC gene could only be accomplished in a mutant E. coli 43R. Even in crude extracts, the acylated acyl-CoA reductase intermediate as well as acyl-CoA reductrase activities could be readily detected.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.6 no.4
• /
• pp.389-396
• /
• 1994

We analyze existing time-dependent mild-slope equations, which were developed by Smith and Sprinks (1975) (or, equivalently, Radder and Dingemans (1985)) and Kubo et al. (1992), in terms of the dispersion relation and energy transport. One-dimensionally in the horizontal direction, we compare the modulation of wave amplitudes for the time-dependent mild-slope equations against the linear Scrodinger equation. In view of the dispersion relation and modulation of wave amplitudes, Smith and Sprinks' model is more accurate in shallower water (kh$\leq$0.2$\pi$) and satisfies the linear Scrodinger equation in very shallow water (kh>0.2$\pi$) and satisfies the linear Scrodinger equation at a point of intermediate water depth (kh=0.3$\pi$). In view of the energy transport, Kubo et al.'s model is more accurate but yields singular solutions at some higher frequency range.

• Proceedings of the KSRS Conference
• /
• 2002.10a
• /
• pp.587-592
• /
• 2002

A new digital correlator fur an airborne synthetic aperture radiometer was designed in order to replace the conventional analog correlator unit which will become very complicated while the number of channels is increasing. The digital correlator uses digital IQ demodulator instead of the intermediate frequency (IF) phase shifter to make the correlation processing performed digitally at base band instead of analogly at IF. This technique has been applied to the digital receiver in softradio. The down-converted IF signals from each pair of receiver channels become low rate base-band digital signals after under-sampled, Digitally Down-Converted (DDC), decimated and filtered by FIR filters. The digital signals are further processed by two digital multipliers (complex correlation), the products are integrated by the integrators and finally the outputs from the integrators compose of the real part and the imaginary part of a sample of the visibility function. This design is tested by comparing the results from digital correlators and that from analog correlators. They are agreed with each other very well. Due to the fact that the digital correlators are realized with the help of Analog-Digital Converter (ADC) chips and the FPGA technology, the realized volume, mass, power consumption and complexity turned out to be greatly reduced compared with that of the analog correlators. Simulations show that the resolution of ADC has an influence on the synthesized antenna patterns, but this can be neglected if more than 2bit is used.