• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.8
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• pp.735-741
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• 2016

Increasing the total length of waveguide-below-cutoff array(WBCA) as it is used to the duct in order to enhance shielding effectiveness, the design could cause higher cost, higher levels of difficulties in construction and the interruption a flow velocity. The multi-layered WBCA can compensate for this problem, which can be designed by crossing each waveguide layer. By conducting simulations from 2-layer to 8-layer structure, it can be observed that the shielding effectiveness increases from 52 dB to 75 dB. Comparing with the original WBCA in a shape of mono layer rectangular, our proposed waveguide becomes similar with the original value as the number of crossing layer increases. In addition, the analysis with the flow of fluid in the duct installed multi-layered WBCA are required. We demonstrate this analysis by doing the flow of fluid simulation, and concluded that the multi-layered WBCA has loss of flow of fluid less than unit rectangular WBCA.

• Journal of Bio-Environment Control
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• v.11 no.2
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• pp.81-87
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• 2002

This study was conducted to investigate the cooling efficiency and growth of tomatoes by root zone cooling device using a pad-box and cultivated system. The structure of the root zone cooling system using a pad-box was four piece of pads bonded an the side and a fan set at the bottom. Cool wind was generated by the outside air which was punched at intervals of 10 cm along three rows. Cold wind flowed to the root zone in the culture medium. The root zone cooling efficiency of cold wind generation by using a pad-box flowing through a wet-pad was determined. Major characteristic of this cuttural system consist of bed filled with a perlite medium and a ventilation pipe using PVC. The cold wind generation by a pad box (CWP) was compared to that of cold wind generation by a radiator (CWR), cold water circulation using a XL-pipe (CWX) and the control (non-cooling). When the temperature of water supplied was 16.2-18.4$^{\circ}C$, temperatures in the medium were 20.5~23.2$^{\circ}C$ for CWP 22.7~24.2$^{\circ}C$ for CWR, 22.8~24.27$^{\circ}C$ for CWX and 23.1~-29.6$^{\circ}C$ for the control. The results show that the cold wind temperature using the pad-box was lower by 1~2$^{\circ}C$ than that of cold water circulation in the XL-pipe and lower by 5~6$^{\circ}C$ than that of the control. Growth such as leaf length, leaf width, fresh weight and dry weight, was greater in three root zone cooling methods than in the control. Root activity was higher in the rat zone cooling methods than in the control. However, there was no significant difference among root zone cooling methods.

• Journal of Bio-Environment Control
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• v.18 no.3
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• pp.185-191
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• 2009

The construction of experimental greenhouses, operating test, and analysis on variation of different environment factors were conducted to provide fundamental data for design of Korean style air-inflated double-layer plastic greenhouse. The development of technology of attaching plastic to the structure and fasteners to be able to keep airtight was required in order to maintain proper static pressure in air space of double layer coverings. The insulation effect of air inflated greenhouse was better than conventional type. The temperature of arch type roof was greater about $2^{\circ}C$ than peach type roof in air inflated greenhouse. It was recommended that the plastic should be attached at the edges without clearance length in order to ease installation and raise airtightness of double layer coverings. The transmittance of arch type roof was greater than peach type in air inflated one span greenhouse. The transmittance of air inflated greenhouse was greater than conventional type due to frame ratio and distance between double layers in three span greenhouse. The condensation occurred on conventional type greenhouse was more than air inflated type. It was required to examine for a long time in order to analyze it quantitatively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1B
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• pp.47-55
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• 2011

This study suggests new synthetic unit hydrograph method considering hydrodynamic characteristic on the basin. The suggested method based on width function GIUH, and the procedure is summarized as follows; 1) Draw up a travel distance distribution map (width function) which is raster of length between from center of individual cells to the outlet by GIS. 2) Calculation of travel time distribution map (rescaled width function) by hydrodynamic parameters and travel distance distribution map. 3) Derivation of IUH and Duration UH from rescaled width function. 4) Comparison of shape of UH between suggested method and existing synthetic unit hydrograph methods. The target basins are selected Ipyeong and Tanbu subwatershed in the Bocheong Basin. The target basins are similar scale (watershed area), but different drainage structure (drainage density et al.). Therefore we anticipate that there are different hydrologic response functions because different hydrodynamic characteristics. As a result of derivation of UH, existing synthetic unit hydrograph methods are similar shape of UHs about Ipyeong and Tanbu watersheds, but the suggested method is different shape of ones. As a result of application to observed data, the peak discharge by suggested method is similar to existing synthetic unit hydrograph methods, but the peak time is well correspondence between those. Henceforth, if the suggested method combines with the rational velocity estimation method, it is useful method for synthetic of UH in ungauged watershed.

• Composites Research
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• v.29 no.5
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• pp.282-287
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• 2016

p-DCPD (poly dicyclopentadiene) is the resin that the versatile mechanical properties can be changeable via the control of inner monomer and catalysts. In this work, to improve the strength of composites, surface treated MGF (milled glass fiber) was used as an reinforcement in p-DCPD by molybdenum (Mo) catalyst matrix. The optimum concentration of surface treatment was obtained and the cohesion of MGF themselves increased with concentration. In case of 0.2 wt% silane concentration, the maximized mechanical properties of MGF/p-DCPD composite exhibited because of minimized MGF cohesion. When butyl silane showing minimizing cohesion was used as the optimized alkyl length, high tensile and flexure strength exhibited due to the steric hindrance effect among MGFs. Mechanical and their fractured surfaces of MGF/p-DCPD composites was compared for 4 different chemical functional groups. Norbornene functional groups containing similar chemical structure to DCPD matrix exhibited higher interfacial adhesion between MGFs and DCPD matrix.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.5
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• pp.1193-1198
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• 2009

Pulse diagnosis is a central diagnosis method used in traditional Oriental medicine. To standardize and modernize the pulse diagnosis method, it is essential to develop an instrument-based reinterpretation of the clinically used pulse images in terms of the physical quantities such as the strength, period, width, length, and depth of the pulse. As a step towards such standardization, we conducted a clinical study on the floating/sinking pulses based on an automated palpation instrument (3D-MAC, Daeyo Medi, Korea) for 213 female subjects in their 20s and 174 female subjects in their 60s. The floating/sinking pulses are the two representative pulse images depending only on the depth of the pulse, and can be conveniently scaled by the coefficient of the floating-sinking pulse ($C_{fs}{\in}(0,1)$), which represents how strong one should apply the hold-down pressure to obtain the maximal pulse strength. As a result, primarily we found that it tends to appear more floating-like pulse ($C_{fs}{\rightarrow}0$) at Gwan and more sinking-like pulse ($C_{fs}{\rightarrow}1$) at Cheek, at both age groups and at both wrists. This result is consistent with a previous study on the geometrical structure of the blood vessel by an ultrasonograph. Second, the pulse tends to be more sinking-like in the age group of 60s than 20s. Finally, the pulses at the right palpation positions were found to be more sinking-like than the left, at both age groups.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.3
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• pp.160-180
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• 2012

We have studied the eukaryotic plankton species diversity to compare the community structure of fresh and brackish waters in the lower reaches of the Nakdong River using metagenomic methods. We constructed 18S rDNA clone libraries of total DNAs extracted from environmental water samples collected at Mulgeum (MG100929, fresh) and Eulsukdo bridge (ES, brackish). Through the steps of colony PCR, PCR-RFLP, sequencing and similarity analysis, we discovered the diverse species composition of eukaryotic plankton. Total 338 clones (170 at MG100929 and 168 at ES) were analyzed, and then we found 74 phylotypes (49 for MG100929 and 25 for ES). From the phylogenetic analysis, we confirmed various eukaryotic plankton of broad range of taxonomic groups, including Stramenopiles, Cryptophyta, Viridiplantae, Alveolata, Rhizaria, Metazoa, and Fungi. We also found several unreported species in Korea and candidates of new taxonomic entities at levels higher than genus. Especially, the cryptic species diversity including unreported phylotypes of Pirsonia (Stramenopiles) and Perkinsea (Alveolata) suggests that the molecular monitoring method can produce new informative biological data in monitoring the changes in the Nakdong River Mouth ecosystem.

• Applied Chemistry for Engineering
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• v.27 no.3
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• pp.291-298
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• 2016

In this study, zwitterionic surfactants were added to liposome systems at different pH conditions to understand the effect of surfactants on liposome characteristics. For this purpose, amine oxide surfactants having different hydrocarbon chain lengths were synthesized and the structure of the resulting product was elucidated by using $^1H$ NMR, $^{13}C$ NMR, and FT-IR. In addition, the physical properties of newly synthesized surfactants such as critical micelle concentration (CMC), surface tension and isoelectric point were measured. The stability characteristics of liposome systems including average particle sizes and zeta potentials were measured by varying pH and hydrocarbon chain lengths of an amine oxide surfactant. Effects of the pH and hydrocarbon chain length of an amine oxide surfactant on fluidity of a liposome membrane were also examined by measuring the deformability and the binding degree between the surfactant and liposome.

• Journal of Life Science
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• v.25 no.11
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• pp.1304-1310
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• 2015

The period circadian clock gene 3 (PER3) plays a role in the mammalian circadian clocksystem. A regular exercise regime may affect the PER3 transcription in skeletal muscle. Although the effects of day length on circadian and circannual processes are well established in humans and mice, the influence of exercise on these processes in the horse has not been investigated. The present study investigated the expression of the PER3 gene following exercise in a thoroughbred breed of Korean horse. In addition, a comprehensive in silico nonsynonymous single nucleotide polymorphism (nsSNP) analysis of the horse PER3 gene and predicted effects of nsSNPs on proteins were examined. The expression of PER3 in skeletal muscle was significantly upregulated after exercise. Four nsSNPs were functionally annotated and analyzed by computational prediction. The total free energy and RMSD values of PER3 gene showed causative mutations. The results showed that nsSNP s395916798 (G72R) was associated with residues that have stabilizing effects on structure and function of PER3 gene. This study documented role of PER3 gene in phenotypic adaptation related to exercise in skeletal muscle. Further, the SNPs in PER3 could serve as useful biomarkers of early recovery after exercise in racehorses.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.10
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• pp.39-50
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• 1998

Wide-band sharp-transition filters are widely used in applications such as wireless CODEC design or medical systems. Since these filters suffer from large sensitivity and roundoff noise, large word-length is required for the VLSI implementation, which increases the hardware size and the power consumption of the chip. In this paper, a low-power implementation technique for digital filters with wide-band sharp-transition characteristics is proposed using CPL (Complementary Pass-Transistor Logic), LWDF (Lattice Wave Digital Filter) and a modified DIFIR (Decomposed & Interpolated FIR) algorithm. To reduce the short-circuit current component in CPL circuits due to threshold voltage reduction through the pass transistor, three different approaches can be used: cross-coupled PMOS latch, PMOS body biasing and weak PMOS latch. Of the three, the cross-coupled PMOS latch approach is the most realistic solution when the noise margin as well as the energy-delay product is considered. To optimize CPL transistor size with insight, the empirical formulas for the delay and energy consumption in the basic structure of CPL circuits were derived from the simulation results. In addition, the filter coefficients are encoded using CSD (Canonic Signed Digit) format and optimized by a coefficient quantization program. The hardware cost is minimized further by a modified DIFIR algorithm. Simulation result shows that the proposed method can achieve about 38% reductions in power consumption compared with the conventional method.