• Korean Journal of Plant Taxonomy
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• v.32 no.3
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• pp.301-338
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• 2002

Morphological characters of sections Rhomboidales (four taxa) and Digitatae (seven taxa) of the subgen. Eucarex (genus Carex, Cyperaceae) were reexamined. The epidermal patterns of perigynium, achene and leaf were investigated by SEM and LM. Morphological characters such as length and width of stem, leaf, bract, spike, scale, perigynium and achene, and shape of cross-sectioned stem, spike, scale, apex of scale, perigynium, beak and base of perigynium, achene, hair present or absent in perigynium, number of involucre and epidermal pattern of perigynium, achene and leaf(shape of fundamental epidermal cell and cell wall, type of silica body, shape of beak epidermal cell and cell wall in perigynium, subsidiary cell shape, size and frequency of stomatal complex of leaf) were useful for the identification of the observed 11 taxa. According to the current study, examined 11 taxa of sections Rhomboidales and Digitatae were distinct from each other regarding by length of leaf, stem, pistillate scale and perigynium, shape and epidermal cell of perigynium beak. C. lanceolata and C. humilis have been confused due to similar morphological characters. C. lanceolata and C. humilis were distinct, however with respect to from length of stem, leaf ligule present or absent, shape of cross-sectioned stem, epidermal patterns of perigynium, achene and leaf. And C. lanceolata could be distinguished from C. pediformis by shape of perigynium and achene, shape of cross-sectioned of stem, epidermal pattern of perigynium, achene and leaf.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.32-39
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• 2021

Recently, necessities of steel form for reinforced concrete beam and girder have been emphasized in building structures for the reduction of the construction period and the labor cost. SY Beam was developed for the these purposes and is roll-formed using thin steel plate. On this research, we tried to evaluate and verify the performance and behavior of SY Beam under construction loading stage as like pouring in situ concrete. For the standard shape of SY beam, structural modelling with various steel thicknesses has carried out using MIDAS GEN program. From results of modelling, the width and height of SY Beam were determined 600mm and 400mm respectively. For 3 SY Beams, the loading experiment was performed to measure vertical and horizontal displacement under stacking sand, concrete block, and bundle of rebar. As a result, the vertical deflection showed a tendency to decrease as the thickness increased. In the horizontal displacement, the trend according to the thickness was not clearly observed. From the evaluation on the loading experiment, it is considered that the SY Beam can secure both workability and structural safety. In particular, the SY Beam(1.2mm) hardly generates horizontal displacement, so it has excellent load-bearing capacity. So, we judged that the SY Beam with 1.2mm steel plate has excellent performance and consider to be immediately commercially available.

• The Journal of the Acoustical Society of Korea
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• v.38 no.3
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• pp.352-362
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• 2019

The old residences and shops in the backside blocks are affected by the traffic noises from the main road. The noise of the backside roads is affected by the following factors such as the height of the roadside buildings, the distance between the road and the backside streets, distance among adjacent roadside buildings, and the difference of the adjacent building heights. The both noise levels on the road and the backside street were measured simultaneously in 15 urban blocks of a city which can be categorized into two types of roadside building plans ; 1) one single building along the street, 2) buildings arranged on one axis beside the road. As the results, there is no significant noise reduction due to the width of the buildings in general. However, in the cases of buildings arranged on one axis beside the road, it was found that the average noise reduction was 12 dB(A) on the basis of the building height of 4 m. Also, it was analysed that for each 4 m increase in the building height, noise reduction occurred by 2 dB(A) beyond building height of 4 m. In general, it was proved that the noise of the back streets is mainly affected by the lowest height of the roadside buildings. It was found that noise is increased by 1 dB(A) for each 4 m increase of the height difference between adjacent buildings. Also, It was revealed that for each 0.5 m increase in the distance between roadside building, noise reduction decreased by 1 dB(A).

• Korean Journal of Environmental Biology
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• v.39 no.1
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• pp.55-67
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• 2021

A 210-day experiment was conducted to examine the effects of starvation on survival, external morphometric traits, and sectioned morphometric traits in Far Eastern catfish(Silurus asotus). The survival rate decreased to 92.2±0.47% in the fed group and to 74.4±2.59% in the starved group. Eight dimensions of Ls, DALPO/Ls, DADOP/Ls, ED/Ls, CH/Ls, BDAA/Ls, BDMA/Ls, and BWAA/Ls showed significant differences (p<0.05), and 16 other dimensions of DALAD/Ls, DPDPL/Ls, HPLAA/Ls, HALAV/Ls, HALOP/Ls, DAUPO/Ls, DADAV/Ls, DADAA/Ls, Max BL/Ls, Man BL/Ls, LD/Ls, HWOP/Ls, DAUF/HL, DAUS/HL, IW/HL, and DAUE/HL were not significantly different among the initial, fed, and starved groups (p>0.05). The fed group showed higher total height (THX), wider width (WX), and larger area (AX) than those of the starved group in each body section. This research provides information on the morphometric traits and body sections of starved Far Eastern catfish. These results can be used as a basic guide to indicate nutritional status and assist in aquaculture methods for Far Eastern catfish. Moreover, the methods used in this study were considered helpful because the survey analysis method can be used to investigate information on the nutritional status of other fish species.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.197-204
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• 2021

This study relates to a device that increases efficiency by reducing air bubbles in a hydraulic system used in hydraulic machinery. The reverse design and product production of the bubble reduction device, which is a commercial product overseas, was carried out. Overseas commercial products were set as the base model, a rotary rotor and an inclined rotor were added to increase the surface area of the fluid, and an annular equal distribution part with a slot in the lower part was additionally applied to distribute the fluid evenly. In addition, internal flow trends were analyzed and a system that evenly distributes the linear flow of fluid was selected as the first improvement model. Based on the first improvement model, a case where the angle of the inclined rotor is 45° was selected as the second improvement model. Based on this, as a result of setting the exit width of the annular equally distributed part as a variable, the bubble reduction efficiency was highest when the lower slot diameter of the annular part was 10mm. Finally, the system in which the average cross-sectional flow velocity decreased by 147% compared to the Base Model was derived as the final improved model.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.6
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• pp.533-544
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• 2021

Ion exchange (IX) performance on the exchanger bed is essentially evaluated for the generation of ultrapure water in electronics and chemical industries and for the corrosion control in nuclear power plants. The breakthrough characteristics of IX bed with multi-component were investigated with both cation- and mixed-IX beds of H- and ETAH-form for four kinds of cation exchange resins by using the combined solution of ethanolamine (ETA) and ammonia (NH₃) at trace NaCl. Unlike major components (ETAH⁺ and NH₄⁺ ), the phenomena of breakthrough and overshooting at bed outlet were not observed by Na⁺ over the test period (> 3 times theoretical exchange capacity of IX bed). The breakthrough from H-form resin bed was sequentially reached by ETAH⁺ and NH₄⁺, while the overshooting was observed for ETAH⁺ at the breakthrough of NH₄⁺. NH₄⁺ was 51.5% higher than ETAH⁺ in terms of the relative selectivity determined with the width of breakthrough zone. At the increased concentration of Na⁺ at bed inlet, the selectivity and the overshooting were decreased and increased, respectively. Na⁺ leakage was higher from ETAH-form resin bed and was not identical for four kinds of cation-exchange resins, which may be reduced by improving the intrinsic property of IX resin.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.1
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• pp.15-25
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• 2020

The aim of this study was to evaluate the change of phenolic compounds after lime-sulphur mixture treatment on Cheorwon onion. Onion is a perennial plant belonging to the lily family. It is native to Persia of Southwest Asia. It is cultivated much in the temperate regions of the world. Onion is a good name for the 'Okchong' to drop blood cholesterol and cardiovascular blood flow to increase the prevention of adult diseases. Cheorwon area is inland, but it has high continental climate due to its high altitude. After the treatment with lime-sulphur mixture, the weight, width and plant height of the onion were not affected. In the phenolic compounds, caffeic acid, ferulic acid, rutin, p-coumaric acid and kaempferol except benzoic acid and quercetin were similar to or less than the control. Therefore, it was concluded that the treatment with lime-sulphur mixture had some effect on phenolic compound contents, benzoic acid and qurercetin.

• Korean Journal of Optics and Photonics
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• v.33 no.4
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• pp.177-186
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• 2022

The performance of a surface plasmon resonance sensor is evaluated based on the sensitivity (nm/RIU) and sharpness from the full width at half maximum (FWHM) and the peak depth of a resonance peak. These factors are determined by the materials and conformational properties of the sensing structure. In this paper, we investigated an optimized insulator-metal-insulator (IMI) multilayer-based surface plasmon resonance sensor structure to simultaneously achieve high sensitivity, narrow FWHM, and deep peak depth while using gold for the metallic film layer which occurs peak broadening. By adopting the optimized structure, sensitivity of 8,390 nm/RIU, FWHM of 11.92 nm, and a resonance peak depth of 93.1% were achieved for 1.45-1.46 refractive index variation of the sensing layer. With the suggested structure conformation, high sensitivity and resolution of sensing performance can be achieved.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.5
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• pp.775-782
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• 2022

In this paper, a novel small-diameter cylindrical post capacitor inserted into an evanescent-mode rectangular waveguide (EMRWG) is proposed for easier tuning. In order to feed the EMRWG, the proposed structure uses a single ridge rectangular waveguide with the same width and height as the waveguide at the input and output ends. The inserted post capacitor are made up a circular groove formed in the center of the lower part of the broad wall of the EMRWG, and a concentric cylindrical post inserted into the upper part. First, the equivalent circuit model for the proposed structure is presented. When the EMRWG and the single ridge waveguide are combined, the joint susceptance and the turns ratio of the ideal transformer are calculated by two simulations using HFSS (3d fullwave simulator, Ansoft Co.) respectively. The susceptance and resonance characteristics of the inserted post were analyzed by using the obtained parameters and the characteristics of the EMRWG. A 2-post filter with a center frequency of 4.5 GHz and a bandwidth of 170 MHz was designed using a WR-90 waveguide, and the simulation results by using the HFSS and CST, equivalent circuit model were in good agreement.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.1
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• pp.20-32
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• 2022

For this study, 313 pedestrians, including students, from two schools participated in the greening project of the school commuting roads in Seoul. These schools were compared to two without street greenspaces to analyze the effects of the green areas on pedestrian satisfaction and the future direction of creation. As a result of the greenspace satisfaction analysis of schools with greenspace, the items that had the greatest effect on overall satisfaction were 'Width of the sidewalk' (37%), 'Harmony with the surrounding landscape' (24.97%), 'The arrangement of trees, grass, and flowers' (18.30%) and 'Overall management' (10.44%). In other words, the item that satisfies most is securing the appropriate width of the sidewalk where the greenspace is located. It is necessary to re-considered creating greenspaces in existing sidewalk spaces and secure a sidewalk width for pedestrian convenience. As a result of the analysis on the direction of greenspace creation, the respondents who experienced greenspaces through the greenspaces on school commuting routes recognized natural features, such as grass and flowers as more important elements as well as noting that landscape and harmony are important. In addition, respondents interested focusing on functionality recognized the need for greenspaces and highly recognized the importance of arranging natural materials, such as trees, grasses, and flowers. This group also recognized the advantages of functionality and the effectiveness of green spaces. Therefore, it is necessary to expand awareness of the effectiveness of greenspaces through environmental education, publicity, and the provision of information boards. More effort will be needed to apply regional and school characteristics rather than uniform composition to the development of greenspaces.