• Journal of the Korean Institute of Landscape Architecture
• /
• v.47 no.1
• /
• pp.88-103
• /
• 2019

This paper aims to identify planting design for the renewal of Okgu Park, located in Siheung, Gyeonggi-do. I designate planting concept fit spatial functions and also suggest planting designs that are proper for a growth environment. The spatial functions of the research site are divided on the basis of the park facilities, its surroundings, and usage. To understand the planting concept, this paper looks into the distribution of plant species and the precise planting structure. To understand the planting concept and the current usage of shade space in the park, I examine the distribution of plant species and the precise planting structure. There are 48 kinds of plants, with Zoysia japonica area (28.84%), Prunus yedoensis (8.0%), Pinus thunbergii (6.73%) and Zelkova serrata (6.38%) taking up the majority. 27 places were chosen for researching the precise planting structure. The research shows that the average green coverage ratio is 38.14% and the average green capacity coefficient is $0.72m^3/m^2$. The growth defective rate of trees in the shade areas is estimated by averaging the classified growth conditions of individual trees per block of shade areas. Areas with an inferior environment for growth and low spatial usage in Okgu Park are selected as subjects for planting design. After comparing the spatial functions with planting concepts and analyzing the growth of plants, I identify $36,236m^2$ areas with inferior growth condition. I also examine structures and the surrounding areas to find areas that require urgent planting improvement, specifically identifying landscape space and shade space around the fountain and the buffer space nearby the North gate. I rearrange spatial functions in the selected areas to devise a planting design considering the existing vegetation, layer structure, and its usage. I set the planting concept and direction to improve the landscape of the selected areas through implementing a planting design so the park users can be satisfied with each space.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.38 no.12
• /
• pp.8-13
• /
• 2001

Cerium oxide ($CeO_2$) thin film has been proposed as a buffer layer between the ferroelectric thin film and the Si substrate in Metal-Ferroelectric-Insulator-Silicon (MFIS) structures for ferroelectric random access memory (FRAM) applications. In this study, $CeO_2$ thin films were etched with $Cl_2$/Ar gas mixture in an inductively coupled plasma (ICP). Etch properties were measured for different gas mixing ratio of $Cl_2$($Cl_2$+Ar) while the other process conditions were fixed at RF power (600 W), dc bias voltage (-200 V), and chamber pressure (15 mTorr). The highest etch rate of $CeO_2$ thin film was 230 ${\AA}$/min and the selectivity of $CeO_2$ to $YMnO_3$ was 1.83 at $Cl_2$($Cl_2$+Ar gas mixing ratio of 0.2. The surface reaction of the etched $CeO_2$ thin films was investigated using x-ray photoelectron spectroscopy (XPS) analysis. There is a Ce-Cl bonding by chemical reaction between Ce and Cl. The results of secondary ion mass spectrometer (SIMS) analysis were compared with the results of XPS analysis and the Ce-Cl bonding was monitored at 176.15 (a.m.u). These results confirm that Ce atoms of $CeO_2$ thin films react with chlorine and a compound such as CeCl remains on the surface of etched $CeO_2$ thin films. These products can be removed by Ar ion bombardment.

• Journal of Life Science
• /
• v.26 no.4
• /
• pp.453-459
• /
• 2016

Agarases are classified into α-agarase and β-agarase that produce agarooligosaccharides and neoagarooligosaccharides, respectively. Neoagarooligosaccharides have whitening effect of skin, delay of starch degradation, and inhibition of bacterial growth etc. Hence, the object of this study was to isolate a novel agarase producing marine bacterium and characterization of its β-agarase. A novel agar-degrading bacterium was isolated from seashore of Namhae at Gyeongnamprovine, Korea and purely cultured with Marine agar 2216 media. The isolated bacterium was identified as Simiduia sp. SH-4 after 16S rRNA gene sequencing. The enzymatic sample was obtained from culture media of Simiduia sp. SH-4. Enzymatic activity was highly increased from 20(30% relative activity) to 30℃ (100%) and decreased from 30 to 40℃(75%) and so more. Relative activity was 100% at pH 6 while those were about 91% and 59% at pH 5.0 and 7.0, respectively, meaning the enzyme possesses narrow optimal pH range. Hence, the enzyme exhibited the maximal activity with 120.4 units/l at pH 6.0 and 30℃ in 20 mM Tris-HCl buffer. Thin layer chromatography (TLC) analysis showed that Simiduia sp. SH-4 produces β-agarase, which hydrolyze agarose to produce biofunctional neoagarooligosaccharides such as neoagarotetraose and neoagarobiose. Hence, broad applications would be possible using Simiduia sp. SH-4 and its enzyme in the food industry, cosmetics and medical fields.

• Journal of Korea Water Resources Association
• /
• v.53 no.1
• /
• pp.1-13
• /
• 2020

The most common approach for computing engineering flow problems at high Reynolds number is still the Reynolds-averaged Navier-Stokes (RANS) computations based on turbulence models with wall functions. The recently developed generalized wall functions blending between the wall-limiting viscous and the outer logarithmic relations ensure a smooth transition of flow quantities across two regions. The performances and convergence properties of widely used turbulence models with wall functions that are applicable for turbulence kinetic energy (TKE), turbulent and specific dissipation rates, and eddy viscosity are presented through a series of near wall flow simulations. The present results show that RNG k-𝜖 model should be carefully applied with small tolerance to get the stable solution when the first grid lies in the buffer layer. The standard k-𝜖 and RNG k-𝜖 models are not sensitive to the selection of wall functions for both TKE and eddy viscosity, while the k-ω SST model should be applied together with kL-wall function for TKE and nutUB-wall functions for eddy viscosity to ensure accurate and stable boundary conditions. The applications to a backward-facing step flow at Re=155,000 reveal that the reattachment length is reasonably well predicted on appropriately refined mesh by all turbulence models, except the standard k-𝜖 model which about 13% underestimates the reattachment length regardless of the grid refinement.

• Journal of the Korean Society of Physical Medicine
• /
• v.9 no.1
• /
• pp.45-53
• /
• 2014

PURPOSE: In this study, we tried to find out what kind of exercise was more effective in sleep disorder by comparing melatonin in blood after applying low intensity with high intensity exercise to sleep disordered rats induced by experiment. METHODS: We used male Sprague-Dawley rats which were 8weeks old and weighted 300g. They were supplied with water and food without any restriction. We kept the room temperature at $25^{\circ}C$ and controld the length of day and night in 12 hours blocks, respectively. We divided the rats 60 into 2 groups. To one group we applied low intensity exercise, and to the other we applied high intensity exercise for 15minutes per day over a period of 4 weeks. We extracted the blood from abdominal aorta before, after exercise, moved into EDTA tube, performed centrifugation. We decanted the serum $200{\mu}l$ from the blood into microcentrifuge tube by samples and moved into polypropylene culture tubes with micro pipette. We split enzyme solution $50{\mu}l$ into the tubes with melatonin direct kits and make them react at $37^{\circ}C$ for 2 hours. We split assay buffer $50{\mu}l$ into each tube and mixed melatonin tracer $50{\mu}l$ and melatonin antiserum $50{\mu}l$, respectively. After we made them react in room temperature, we decanted the superficial layer with a centrifuge and measured the activity for 1 minute by competitive method with ${\gamma}$-counter equipment. We draw a standard curve through logit-log graph with CPM(counts per minute) and counted the melatonin by B/B0. We conducted independent t-test to examine the homogeneous of melatonin value of before low-intensity and high-intensity exercise. We performed paired t-test to compare before and after low-intensity and high-intensity exercise, respectively. We carried out independent t-test to compare melatonin value after low-intensity and high-intensity exercise. Significance level was .05. RESULTS: The results were as follows; firstly melatonin was more increased in the group who was exposed to high intensity exercise when we compared before to after high and low intensity exercise, respectively. Secondly, high intensity exercise was more effective than low intensity exercise when we compared the two. CONCLUSION: In conclusion, secretion of melatonin which is the material of sleep improvement could be promoted by high intensity exercise. Low intensity exercise acted as a stress rather than improving sleep and had a negative effect on the secretion of melatonin because the melatonin was affected by stress.

• Journal of Wetlands Research
• /
• v.15 no.4
• /
• pp.543-553
• /
• 2013

In Korea, there have been many studies and progresses on various types of pilot scale or commercialized field scale Best Management Practices(BMP) during the last 10 years. Runoff characteristics of diffuse pollutants from different land uses are well identified and documented. However, for the coastal area connected directly with shoreline, runoff patterns and management schemes of non-point pollution were not fully studied. Recently, coastal area is emerging as a new development axis especially in west coast side of Korea such as Incheon city and Chungnam province, thus urbanized area rapidly increased but there are no buffer zones and BMP facilities to aim at preventing direct discharge of the first flush into coastal sea and beaches. In this study, parking area in Deacheon harbor, Boryeong City in Chungnam Province was selected and rainfall runoff was monitored for two year period in order to examine run-off features from which proper type of BMP suitable for coastal area is proposed. Coastal area usually has a low ground water level and consists of plain land, so that large scale BMP such as storm water retention pond and wetland requiring great excavation works is not best management plan. In addition, monitoring study shows that storm water from the paved parking area has a high salinity compared with those in storm water from the inland. High salinity is detrimental for the vegetation. Therefore, BMP employing least vegetative cover and also in terms of maintenance is a good option such as infiltration trench and porous pavement.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.6 no.1
• /
• pp.28-37
• /
• 1996

Benzidine, an aromatic amine used primarily in the manufacture of azo dyes, is recognized as a urinary bladder carcinogen in humans. In rats, mice, and hamsters, chronic exposure to benzidine resulted in tumors of the liver. The present study was undertaken to suggest analyzing the metabolites of benzidine with the optimal condition, identify the metabolites of benzidine, and observe time variance of the metabolites in the isolated perfusated rat liver. N-acetylbenzidine was synthesized by acetylation of benzidine with acetic anhydride and separated by thin layer chromatography(TLC) and high performance liquid chromatography(HPLC). To analysis benzidine and the metabolites of benzidine, HPLC operating condition has been optimized by means of preliminary experiment. The mobile phase consisted of acetonitrile(37%) in phosphate buffer, flow rate maintained at 1.0 ml/min. Optimal detective conditions were electrochemicaldetector(ECD) at 0.75 V for benzidine and N-acetylbenzidine and ultravioletdetector(UVD) at 287 nm for N,N'-diacetylbenzidine. The separation system was composed of a guard column and a separation column(Polymer C18, $4.6{\times}250cm$) at a temparature of $40^{\circ}C$. The perfusion system was equilibrated for 30 minutes before addition of benzidine to the perfusate. Samples of the perfusate were collected at time intervals(0, 10, 20, 30, 60, 90, 120 min) during the 2 hour perfusion. Before analyzing samples by HPLC/ECD/UVD, samples had been treated with sep-pak. Samples of perfusate analyzed by HPLC/ECD/UVD and the metabolites of benzidine in the isolated perfused rat liver were N-acetylbenzidine and N,N'-diacetylbenzidine. Benzidine metabolized over 60% during the initial 30 minutes of perfusion, extensively by 1 hour, and was undetectable in the perfusate. N-acetylbenzidine increased by 30 minutes of perfusion, declined. N,N'-diacetylbenzidine increased the 0-90 minutes period, remained constant during the 90-120 minutes period.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.342-343
• /
• 2013

AlSb is a promising material for optical devices, particularly for high-frequency and nonlinear-optical applications. And AlSb offers significant potential for devices such as quantum-well lasers, laser diodes, and heterojunction bipolar transistors. In this work we study molecular beam epitaxy (MBE) growth of an unstrained AISb film on a GaAs substrate and identify the real-time monitoring capabilities of in situ spectroscopic ellipsometry (SE). The samples were fabricated on semi-insulating (0 0 1) GaAs substrates using MBE system. A rotating sample stage ensured uniform film growth. The substrate was first heated to $620^{\circ}C$ under As2 to remove surface oxides. A GaAs buffer layer approximately 200 nm- thick was then grown at $580^{\circ}C$. During the temperature changing process from $580^{\circ}C$ to $530^{\circ}C$, As2 flux is maintained with the shutter for Ga being closed and the reflection high-energy electron diffraction (RHEED) pattern remaining at ($2{\times}4$). Upon reaching the preset temperature of $530^{\circ}C$, As shutter was promptly closed with Sb shutter open, resulting in the change of RHEED pattern from ($2{\times}4$) to ($1{\times}3$). This was followed by the growth of AlSb while using a rotating-compensator SE with a charge-coupled-device (CCD) detector to obtain real-time SE spectra from 0.74 to 6.48 eV. Fig. 1 shows the real time measured SE spectra of AlSb on GaAs in growth process. In the Fig. 1 (a), a change of ellipsometric parameter ${\Delta}$ is observed. The ${\Delta}$ is the parameter which contains thickness information of the sample, and it changes in a periodic from 0 to 180o with growth. The significant change of ${\Delta}$ at~0.4 min means that the growth of AlSb on GaAs has been started. Fig. 1b shows the changes of dielectric function with time over the range 0.74~6.48 eV. These changes mean phase transition from pseudodielectric function of GaAs to AlSb at~0.44 min. Fig. 2 shows the observed RHEED patterns in the growth process. The observed RHEED pattern of GaAs is ($2{\times}4$), and the pattern changes into ($1{\times}3$) with starting the growth of AlSb. This means that the RHEED pattern is in agreement with the result of SE measurements. These data show the importance and sensitivity of SE for real-time monitoring for materials growth by MBE. We performed the real-time monitoring of AlSb growth by using SE measurements, and it is good agreement with the results of RHEED pattern. This fact proves the importance and the sensitivity of SE technique for the real-time monitoring of film growth by using ellipsometry. We believe that these results will be useful in a number of contexts including more accurate optical properties for high speed device engineering.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.33 no.5 s.112
• /
• pp.43-56
• /
• 2005

This study was conducted to examine the inhabitation of wild birds at the World Cup Park and to offer the Park ecological management data. Land use md actual vegetation were examined to analyze the inhabitation of wild birds. Characteristics of bird communities were analyzed by dominance, density, diversity index and guild concept. You compare inhabitation before and after the Park was built. We classified the land use and actual vegetation into twenty-six types. Robinia pseudoacacia dominated the study area. Pyeonghwa Park and Nanji-cheon Park were simple-layer structures composed of alien woody species. The observed birds after the World Cup Park included 33 families 77 species, and 9,751 individuals. Among Wild Life types, the shrub and bush type was dominant. There were 26 species of resident birds, 20 species of summer visitors, 18 species of winter visitors, and 12 species of passage migrants. The following numbers of species and individuals were observed: in Hanul park, 38 species, 3,151 individuals; in Noul park, 45 species, 2,061 individuals; in Nanji-cheon park, 42 species, 2,742 individuals; in Pyeonghwa park, 29 species, 875 individuals; and in Maebongsan(Mt.) area, 35 species, 922 individuals. Species diversities for each area were as follows: Noul park, 2.613; Hanul park, 2,301; Nanji-cheon, 2.228; and Pyeonghwa park, 2,019; and each season: summer, 2.652; spring, 2.650: winter, 2.561; and autumn 2.176. The diversity of species increased from 1.135 in 1994 to 2.324 in 2001. We recommended that the park be differented into different ecological areas in order to encourage the appearance of wild birds at the World Cup Park. The management area was divided into three districts(conservation area, preservation and restoration area, use area). The conservation area was established to the west of a waste landfill and in the downstream area of NanJi-cheon, the preservation and restoration area was established in the midstream area of Nanji-cheon, and the use area was established in the buffer zone of Pyeonghwa Park and the Nanji pond greenspace.

• Journal of the Korean Ceramic Society
• /
• v.39 no.6
• /
• pp.582-588
• /
• 2002

IrO$_2$-RuO$_2$ films were deposited on plasma sprayed TiO$_2$ buffer layer above Ti metal by sol-gel and dip-coating method. Organic vehicle (ethyl cellulose and $\alpha$-terpineol) and glass frit were added to improve adherence of the coatings. Taguchi method and L$_{18}$ (2$^1$$\times$3$^{7}$ ) orthogonal arrays were evalvated in terms of current density to determine the optimal combination of levels of factors that best satisfy the bigger is better quality characteristic. The observed conditions were as fellows: ethyl cellulose (100 cp), drying temperature and time (17$0^{\circ}C$,20 min), heat treatment temperature and time (75$0^{\circ}C$,10 min), the weight ratio of IrO$_2$-RuO/powders to glass frit (99:5), final heat treatment time (120 min) and flow rate of air (5 sccm), respectively. ANOVA analysis suggested that the influence of the factors within $\alpha$= 0.1 was significant with a 90% confidence level.