• Journal of Korean Society of Steel Construction
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• v.24 no.1
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• pp.129-136
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• 2012

This study seeks to evaluate the welding characteristics of SHN400 steel, which is suitable for the steel material used in building structures in KS. For this purpose, the Y-groove weld crack test and hardness, tensile, bending, cross tensile, and charpy V notch tests at the welding point were conducted with specimens taken from the highest, the thickest and the commonly used H-beams for girder or beam members. Each test was conducted under the KS test conditions. All tests results satisfied the requirements of KS and the welding requirements for the proper inelastic behavior of structure, indicating that SHN400 can be used for the building structure as a structural material.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.4
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• pp.634-639
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• 1997

In order to obtain the basic knowledges for the effective seed production of Perinereis aibuhitensis, sediment preference, burrow shape and behavior with in burrow were investigated in the laboratory. The highest value in both sediment preference and survival rate of P. aibuhitensis were shown at fine sand below 0.10 mm in the mean diameter. The worm made various types of burrows, such as J, L, O, Y and I shapes. Generally, only one individual inhabits in a burrow with head-up, but when excreting, it positions up-side down.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.3
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• pp.1-6
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• 1998

The purpose of this study was to investigate the scope of color perception for Japan standard color. In addition to, we compared the difference in the color perception between the Korean and the Japanese undergraduates. 140 male and 119 female Japanese undergraduates were selected as the random sample. Color perception was made with the naked eyes. Minolta Chroma Metre CR 300 was used for physical measurement of the color. The results were as follows, 1) Japanese students' perceived color perception was classified into four large groups: simple group includes Red, Yellow, Blue, White, Gray and Black, X(-axis)group includes Green, Red Purple, Y(-axis)group includes Green, complex group includes Blue Green, Purple, Purple Blue, Red Purple. 2) There is difference between Korean color perception and Japanese; for Yellow Red, Blue, Blue Green, Red Purple. 3) There is little difference between the values of standard color and mean percept color for Yellow while big difference for Blue. And as for as country was concerned, Korean is more accurate than Japanese in color perception.

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.41-48
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• 2009

This study was conducted to investigate optimum cultural conditions for Amanita hemibapha isolated in Korea and its hyphae characteristics. Micrographs shows the presence of clamp connection. A. hemibapha grows as mycelial form(M-phase) 2-4 ${\mu}m$ and yeast-like form(Y-phase) 7-8 ${\mu}m$. The fungal spores were broadly elliptical and papillate, 8-11 ${\times}$ 6-9 ${\mu}m$ in size. The nucleotide sequence analysis of the ITS of nuclear ribosomal DNA from sporocarps and in-vitro-grown mycelium supported the fungal species is Amanita hemibapha. A. hemibapha showed sequence similarity in the ITS rDNA with A. caesarea(97.5) and A. jacksonii(98.5%) which are morphologically similar species to A. hemibapha. The optimal pH and temperature for mycelial growth of A. hemibapha were pH 6.0 and $28^{\circ}C$, respectively. The fungal species showed best growth in SYP and GYS medium. A. hemibapha grew well with mannitol and glucose as carbon sources and peptone as a nitrogen source.

• Journal of the Korean Magnetics Society
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• v.6 no.2
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• pp.73-79
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• 1996

Y-type hexagonal ferrites$(Ba_{2}Me_{2}Fe_{12}O_{22}:Me=transition metal)$ have promising electromagnetic properties in GHz range. Co and Zn are good candidates for the transition metal. To understand their role on the properties, it is thus necessary to study the ion(s) distribution in that complex Y-type hexagonal ferrite structure. The authors report Mossbauer spectroscopic results from very reliable samples, which has been extensively characterized by chemical analysis, Rietveld analysis of X-ray diffraction patterns, and magnetic property measurements. Analyzing two samples, $Co_{2}Y$ and $Co_{1.6}Zn_{0.4}Y$, conclusions are made as follow: (1) Co ions prefer the tetrahedral interstitial sites in the S-block $(6c_{IV})$ and the octahedral sites $(18h_{VI})$ at the interface of S- and T-block. (2) Partial substitution of Co with Zn (within the experimental range) does not disturb the Fe distribution.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.2
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• pp.355-362
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• 2015

In this study, we have fabricated 9.385[GHz] circulator that is composed of WR112 waveguide and Ferrite for X-band radar. For designing Ferrite, B/R mode(Below Resonance mode) was used and calculated the condition of 120 degree rotation of the electric field in Ferrite and calculated internal DC magnetic field and external DC magnetic field. Also, dielectric materials of the same shape with Ferrite was filled between two Ferrite for improving the performance of the circulator, including impedance matching, bandwidth, quality factor, insertion loss. To obtain optimum shape of the Ferrite and dielectric material, we used CST MWS. Simulation result of the circulator is that 1.02 : 1 VSWR, -40dB isolation, 0.2dB insertion loss and measurement result is that 1.03 : 1, -38dB, 1.2dB at 9.385[GHz]. We can get good agreement at isolation and VSWR, but insertion loss was 1 dB great than simulation result.

• Journal of the Korean Institute of Gas
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• v.19 no.4
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• pp.55-61
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• 2015

In this paper, the displacement behavior characteristic of hollow rollers with various cross sectional area profiles and circular plate for load supporting capacity increment has been presented using a finite element method. The FEM results present that the hollow roller with X-shaped or Y-shaped columns between outer tube, middle tube and inner tube reduces a maximum displacement at the middle length of hollow rollers. And the circular plate, which is inserted at the middle of the hollow roller, is very useful to reduce the maximum displacement of hollow rollers with the plate thickness of 30~40mm. This paper presents the weight vs the maximum displacement ratio in which is represented for the optimized design as a function of a hollow roller total weight. The FEM analyzed results recommend the design model 4, 5 and 6 of hollow rollers for decreasing the ratio of maximum displacement and total weight of hollow rollers.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.7 no.4
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• pp.19-25
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• 1993

The purpose of this study was to investigate the scope of color perception for Korean standard color. 99 male and 126 female university students were selected as the random sample. Color perception was made with the naked eyes. Minolta Chroma Meter CR 300 was used for physical measurement of the color. The results were as follows, 1) Color perception was classified into four large groups: simple group includes Red, Yellow Red, Pale Red Yellow, Yellow, X( -axis)group includes Pale Yellow Red, Pale Green Yellow, Green Yellow, Purple, Pale Red Purple, Y( -axis)group includes Pale Blue Green, Blue Green, Pale Green Blue, Blue, Pale Ptuple Blue, complex group includes Pale Yellow Green, Green, Purple Blue, Pale Blue Purple, Red Purple, Pale Purple Red. 2) There is little difference between the values of standard color and mean percept color for Blue, Yellow, Pale Green Yellow, Green Yellow, Pale Yellow Green, Green, Pale Blue Green, Blue Green, Purple, while big difference for Blue, Pale Green Blue, Pale Red Purple, Pale Purple Red. 3) As for as sex was concerned, female is more accurate than male in color perception.

• Journal of Korean Society of Forest Science
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• v.85 no.1
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• pp.120-129
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• 1996

This study was carried out to investigate the hydraulic architecture such as relative hydraulic conductivity, Leaf specific conductivity(LSC), Huber value, Specific conductivity of the stem, branch and Junctions of stem-to-branch in Quercus mongolica trees. The hydraulic architecture of various hydraulic conductivities of stem and branch was described. The results obtained were summarized as follows : 1. The range of relative hydraulic conductivity was $2.5526{\times}10^{-12}$ to $1.2260{\times}10^{-10}m^2$ in stems, $1.6279{\times}10^{-11}$ to $6.8378{\times}10^{-11}m^2$ in branches. The relative hydraulic conductivities increased with decreasing diameter of stem and branch. The relative hydraulic conductivity of one-year-old terminal shoots were two times greater than that of the lateral shoots. 2. LSC value was larger at the top than at the base in stem. LSC is much smaller in branches than in stem ; especially smallest at branching part. 3. Hydraulic conductivities of the branching part appeared the different values with the 4 type and 4 type. Relative hydraulic conductivity, LSC, Specific conductivity and mean vessel diameter in type branching part were larger in stem than in branch part, but not found in the branching part of Y type. 4. LSC and Specific conductivity of stem increased with decreasing diameter, but Huber value slowly increased with decreasing diameter ; especially highest at less than 1cm diameter. 5. LSC, Huber value, and mean diameter of vessels were larger at 1-year-old leader shoots than at lateral shoots. 6. The mean vessel diameter in various parts of a tree decreased with decreasing diameter of stem, but the number of vessels per unit area($mm^{-2}$) increased reversely. Mean vessel diameter in stem decreased sharply at earlywood and slowly at latewood with decreasing diameter of stem.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.4
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• pp.449-456
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• 2015

In this paper, attaching various damping plates to the cylindrical structure and performing numerical simulations try to study heave RAO and natural period for cylinder. Most of all, we identified heave RAO of the cylinder by simulations of the motion and the wave. And then, we performed numerical simulations by changing the size and shape of heave damping plate attached to the cylinder and reviewed the heave RAO and natural period for each case. The conclusions of this research are as follows. Firstly, the natural period of cylindrical structure is increased by attached to the cylinder with heave damping plate and the heave RAO of cylindrical structure is reduced in the peak period for incident wave by attached to the cylinder with from the size of 1.30D for heave damping plate. Secondly, circular plate has long natural period than Y-type plate in all of these sections. Finally, the motion response spectrum considering the marine environment of Piranema field was identified as the heave motion of cylindrical structure is remarkably reduced with both circular plate and Y-type plate in the peak period for incident wave.