• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.6
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• pp.17-25
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• 2018

This study was conducted to calculate the optimum height of trees, estimating a model for the prediction of tree growth for the landscape improvement of the Gyeonghoeru area. For the verification of measures for management, this study conducted a photographic survey of the Gyeonghoeru area and used the Pressler's formula to examine the growth rate of the pine forest of Mansesan. The results of the study are as follows. First, as a result of a field survey and landscape analysis, trees in the Gyeonghoeru area are large ones with more than a diameter at breast height of 30cm, except for weeping cherry trees and persimmon trees, and especially, it is necessary to manage them or replace with small trees through the landscape of Mansesan, which screens the landscape and pruning the trees in the terraced flower garden in the north. Second, as a result of a measurement of the growth rate of trees, for 10 years on average, they grew up by 14% in source diameter and 5% in tree height 5% in south of Mansesan and by 7% in source diameter and 2.4% in tree height in the north of Mansesan. Furthermore, when a simulation was prepared based on the measured growth rate of trees, it was found out that 20 years later, on the landscape on the second floor of Gyeonghoeru, the pine forest of Mansesan would cut off the skyline of Mt. Inwang-san. Third, this study analyzed a landscape improvement simulation and proposed a plan for tree management to take a view of the landscape of the Gyeonghoeru area. This study has a significance that it drew an efficient planting maintenance policy, considering the landscape characteristics of the Gyeonghoeru area.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.2
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• pp.81-87
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• 2022

Paper is a promising alternative to petroleum-based plastic materials for sustainable packaging applications. However, paper exhibits poor gas and water vapor barrier properties, which restrict its effective application in the packaging industry. To enhance the properties of papers, sodium caseinate (CasNa)/transglutaminase (TG) coating solutions with various TG contents were prepared and coated on the papers. The chemical and morphological structures, mechanical properties, seal strength, and water vapor barrier properties of the coated papers were thoroughly investigated. The paper properties depended significantly on the chemical and morphological structures. Pristine CasNa and CasNa/TG coating solutions were evenly coated on the paper surfaces, without any cracks. The chemical structure of the CasNa/TG coated papers was slightly influenced by TG addition, resulting in increased elongation at break and enhanced water barrier properties. To promote the use of CasNa-coated papers in packaging applications, additional investigations must be performed to prevent gas and moisture permeation and enhance the mechanical strength of these papers via chemical reactions and introduction of organic/inorganic composites.

• Journal of Korean Society of Forest Science
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• v.49 no.1
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• pp.11-31
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• 1980

The morphological, anatomical and physiological traits were eximined for Populus alba ${\times}$ glandulosa which is an important planting species in Korea. The results obtained are as follows: 1. External characters in the leaf shape and chaff shape in the catkin were inherited as incomplete dominance but nectar gland was inherited as dominance. 2. Among the 15 selected clones, 9 clones were male, 2 clones female and 2 clones monoecious. 3. There were well-developed cork layers and bast fiber bundles in the bark. 4. Primordial leaves composed of 3 layers of cells and those undifferentiated into palisade and spongy parenchymas differed in its origin. 5. Leaf scare consisted of two kinds of tissues; one is connected to vascular bundle and the other not to vascular bundle. Tissues which had been connected to vascular bundle were isolated with only 2 or 3 layers of cork cells from the outside. 6. There was complicated arrangement in the vascular bundle of petioles. 7. Growth of the hybrid was sensitively influenced by external temperature, day-length and amount of light. In particular, it was apparent in height growth. 8. Flatness, loam soils and a $60{\times}60cm$ spacing might be best factors for the growth of P. alba ${\times}$ glandulosa. 9. The rooting of 15 clones was dependant upon external factors. 10. The growth of P. alba ${\times}$ glandulosa was best at around 80% of soil moisture content on the basis of plot water capacity. 11. Temperature difference between inside and outside stems below 100cm during the winter was the greatest at the south among seasons and among directions. 12. The sap movement was markedly influenced by air temperature, relative humidity in forest stand and moisture content in stem. 13. Total sugars in the cortex changed with season but did not differ in the dircetion of the stem. 14. Isoperoxidase variations in the leaf were different among 15 clones. Thus, it may be useful as a criterium for clonal identification. 15. The rate of soil moisture content decreased at a rapid slope was faster than that at a slow slope. Poor growth of P. alba ${\times}$ glandulosa at the slope was probably due to depletion of soil moisture.

• Journal of Chest Surgery
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• v.35 no.3
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• pp.171-176
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• 2002

Background: Blood-foreign interaction cause activation of coagulation and inflammatory process that may lead to multiorgan dysfunction and determine the surgical outcomes. Of the methods for assessing the biocompatibility, the platelet adhesion study is considered as the most valuable evaluation step in blood-foreign interaction. As the most studies have used in-vitro or ex-vivo conditions, we have developed a technique of quantification for platelet adhesion on the blood contact surface by using in-vivo injection of radioactive platelets. Material and Method: A coupled bypass circuit was designed to connect the proximal and descending thoracic aorta in 6 piglets(20∼25 Kg). One side of the circuit tube was consisted of a heparin coated PVC tube(10mm in ID, n=6, Experimental group), and the other, a non-heparin coated PVC tube(10mm in ID, n=6, Control group). After cannulation, the blood was circulated through the circuit for 2 hours. Platelet concentrate was prepared from homologous pig blood 24 hours before the experiment. The platelet concentrate was incubated with Tc-99m-HMPAO for 30 min and then centrifuged for 10 min. The supernatant was discarded and the radio-labeling efficacy was measured. The radio-labeled platelet concentrate was mixed with the autologous plasma to make the volume 5 ml, and the mixture was injected intravenously into the experimental animal. After 2 hour circulation, 5 pieces of the specimen(10mm in length each) were obtained from each PVC tube. The radioisotopes were counted with a gamma counter(Cobra ll, Packard, USA), and the ratio of radioisotope count was compared between the control and experimental group. Result: The radioisotope count number was 537.3221.1 Ci/min in the control group and 311.1 184.5 Ci/min in the experimental group(p=0.0104). The ratio between the groups was 1 to 0.58 (p=0.004). Conclusion: In vivo quantification using technetium-99m-HMPAO labeled platelets is simple and reproducible in evaluating platelet adhesion on a foreign surface. We suggest this technique to be a useful tool for blood compatibility test.

• Journal of the Korean earth science society
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• v.43 no.6
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• pp.691-711
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• 2022

The state-of-the-art Earth system model as a virtual Earth is required for studies of current and future climate change or climate crises. This complex numerical model can account for almost all human activities and natural phenomena affecting the atmosphere of Earth. The Unified Model (UM) from the United Kingdom Meteorological Office (UK Met Office) is among the best Earth system models as a scientific tool for studying the atmosphere. However, owing to the expansive numerical integration cost and substantial output size required to maintain the UM, individual research groups have had to rely only on supercomputers. The limitations of computer resources, especially the computer environment being blocked from outside network connections, reduce the efficiency and effectiveness of conducting research using the model, as well as improving the component codes. Therefore, this study has presented detailed guidance for installing a new version of the UM on high-performance parallel computers (Linux clusters) owned by individual researchers, which would help researchers to easily work with the UM. The numerical integration performance of the UM on Linux clusters was also evaluated for two different model resolutions, namely N96L85 (1.875° ×1.25° with 85 vertical levels up to 85 km) and N48L70 (3.75° ×2.5° with 70 vertical levels up to 80 km). The one-month integration times using 256 cores for the AMIP and CMIP simulations of N96L85 resolution were 169 and 205 min, respectively. The one-month integration time for an N48L70 AMIP run using 252 cores was 33 min. Simulated results on 2-m surface temperature and precipitation intensity were compared with ERA5 re-analysis data. The spatial distributions of the simulated results were qualitatively compared to those of ERA5 in terms of spatial distribution, despite the quantitative differences caused by different resolutions and atmosphere-ocean coupling. In conclusion, this study has confirmed that UM can be successfully installed and used in high-performance Linux clusters.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.229-235
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• 2001

The thermal and photometric properties of mulching materials modify the radiation and energy balance on the mulched soil surface and thereby change the soil temperature. The soil surface energy balances and soil temperatures under the mulching treatments of non-mulched control, recycled paper (RPM), and black polyethylene film (BPFM) were compared before and after the establishment of potato canopy. On August 30 in 1998 when potato was not emerged yet and solar radiation was 17.9 MJ $m^{-2}$${day}^{-1}$ , the net radiation of the soil surface was estimated as 10.(1, 2. 4, and 1.3 MJ $m^{-2}$${day}^{-1}$ under the control, BPFM, and RPM, respectively. The sensible and latent heat loss from the soil surface was 9.65 MJ $m^{-2}$${day}^{-1}$ in the control, most of the net radiation being lost through evaporation and convection, whereas it amounted only to 1.39 MJ $m^{-2}$${day}^{-1}$ in BPFM and 1.36 MJ $m^{-2}$${day}^{-1}$ in RPM. Therefore, the soil heat fluxes were 0.36 1.02, and 0.06 MJ m$^{-2}$ day$^{-1}$ under the control, BPFM and RPM, respectively. On September 27 when potato canopy was fully developed, the soil surface net radiation in the control was sharply decreased as compared to that of Aug. 30, whereas the net radiation of the mulched soil surfaces showed little changes. The soil heat flux was -0.01, 0.95, and 0.12 MJ $m^{-2}$${day}^{-1}$ at the soil surface under the control, BPFM and RPM, respectively. As the mulching treatments brought about such alteration of energy partitioning into the soil, the highest soil temperature was recorded in BPFM and the lowest in RMP without regard to potato canopy development. However, the soil temperature differences among the treatments become smaller when potato canopy were fully developed.

• Journal of Preventive Medicine and Public Health
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• v.31 no.1 s.60
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• pp.91-103
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• 1998

Under experimental conditions, UVB radiation, a type of ultra violet radiation, has shown to .elate with the occurrence of skin erythema (sun-burn) in human and skin cancer in experimental animal. Cumulative exposure to UVB is also believed to be at least partly responsible for the 'aging' process of the skin in human. It has also been observed to have an effect of altering DNA (deoxyribonucleic acid). UVB radiation is both an initiator and a promoter of non-melanoma skin cancer. Meta-analysis is a new discipline that critically reviews and statistically combines the results of previous researches. A recent review of meta-analysis in the field of public health emphasized its growing importance. Using a meta-analysis in this study, we explored more reliable dose-response relationships between UVB radiation and skin cancer incidence. We estimated skin cancer incidence using measured UVB radiation dose at a local area of Seoul (Shin chou-dong). The studies showing the dose-response relationships between UVB radiation and non-melanoma skin cancer incidence were searched and selected for a meta-analysis. The data for 7 reported epidemiological studies of three counties (USA, England, Australia) were pooled to estimated the risk. We estimated rate of incidence change of skin cancer using pooled data by meta-analysis method, and exponential and power models. Using either model, the regression coefficients for UVB did not differ significantly by gender and age. In each analysis of variance, non-melanoma skin cancer incidence after removing the gender and age and UVB effects was significant (p>0.01). The coefficients for UVB dose were estimated $2.07\times10^{-6}$ by the exponential model and 2.49 by the power model. At a local area of Seoul (Shinchon-Dong), BAF value were estimated 1.90 and 2.51 by the exponential and power model, respectively. The estimated BAP value were increased statistical power than that of primary studies that using a meta-analysis method.

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.137-143
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• 1994

Enhancement or diminution of leukocyte migration to the specific site might be important factors for the development of inflammatory diseases. To investigate the effects of non-steroidal anti-inflammatory drugs (NSAIDs) on chemotaxis of neutrophil, we obtained neutrophils by Hypaque-Ficoll step gradient centrifugation and tested the effects of seven drugs on the n-formyl-leucyl-phenylalanine (FMLP)-induced migration of neutrophil using a 48-well micro chemotaxis assembly. Oxyphenbutazone, phenylbutazone, sulindac, zomepirac, and ibuprofen suppressed the migration of neutrophil at the therapeutic concentrations, however, indomethacin showed stimulation effect. IC50s for inhibition of neutrophil migration by these drugs are less than 100uM. When drugs were preincubated with FMLP, no inhibition on migration of neutrophil was observed. These results indicated that inhibitory effects of these drugs on migration of neutrophil might be related to the receptor sites of neutrophil rather than molecular inactivation of chemoattractant (FMLP). In conclusion, we suggested that the property of inhibition effects on neutrophil migration of several NSAIDs might be another mode of pharmacological action for anti-iflammatory effect, which showed significant effects at concentrations below therapeutic levels, in addition to cyclooxygenase inhibition.

• Journal of the Korean Vacuum Society
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• v.21 no.5
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• pp.273-278
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• 2012

Over the last decade, the hafnium-based gate dielectric materials have been studied for many application fields. Because these materials had excellent behaviors for suppressing the quantum-mechanical tunneling through the thinner dielectric layer with higher dielectric constant (high-K) than $SiO_2$ gate oxides. Although high-K materials compensated the deterioration of electrical properties for decreasing the thickness of dielectric layer in MOSFET structure, their nano-mechanical properties of $HfO_2$ thin film features were hardly known. Thus, we examined nano-mechanical properties of the Hafnium oxide ($HfO_2$) thin film in order to optimize the gate dielectric layer. The $HfO_2$ thin films were deposited by rf magnetron sputter using hafnium (99.99%) target according to various oxygen gas flows. After deposition, the $HfO_2$ thin films were annealed after annealing at $400^{\circ}C$, $600^{\circ}C$ and $800^{\circ}C$ for 20 min in nitrogen ambient. From the results, the current density of $HfO_2$ thin film for 8 sccm oxygen gas flow became better performance with increasing annealing temperature. The nano-indenter and Weibull distribution were measured by a quantitative calculation of the thin film stress. The $HfO_2$ thin film after annealing at $400^{\circ}C$ had tensile stress. However, the $HfO_2$ thin film with increasing the annealing temperature up to $800^{\circ}C$ had changed compressive stress. This could be due to the nanocrystal of the $HfO_2$ thin film. In particular, the $HfO_2$ thin film after annealing at $400^{\circ}C$ had lower tensile stress, such as 5.35 GPa for the oxygen gas flow of 4 sccm and 5.54 GPa for the oxygen gas flow of 8 sccm. While the $HfO_2$ thin film after annealing at $800^{\circ}C$ had increased the stress value, such as 9.09 GPa for the oxygen gas flow of 4 sccm and 8.17 GPa for the oxygen gas flow of 8 sccm. From these results, the temperature dependence of stress state of $HfO_2$ thin films were understood.

• Progress in Medical Physics
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• v.19 no.1
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• pp.73-79
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• 2008

Retinal prosthesis is regarded as the most feasible method for the blind caused by retinal diseases such as retinitis pigmentosa (RP) or age related macular degeneration (AMD). Recently Korean consortium launched for developing retinal prosthesis. One of the prerequisites for the success of retinal prosthesis is the optimization of the electrical stimuli applied through the prosthesis. Since electrical characteristics of degenerate retina are expected to differ from those of normal retina, we performed voltage stimulation experiment both in normal and degenerate retina to provide a guideline for the optimization of electrical stimulation for the upcoming prosthesis. After isolation of retina, retinal patch was attached with the ganglion cell side facing the surface of microelectrode arrays (MEA). $8{\times}8$ grid layout MEA (electrode diameter: $30{\mu}m$, electrode spacing: $200{\mu}m$, and impedance: $50k{\Omega}$ at 1 kHz) was used to record in-vitro retinal ganglion cell activity. Mono-polar electrical stimulation was applied through one of the 60 MEA channel, and the remaining channels were used for recording. The electrical stimulus was a constant voltage, charge-balanced biphasic, anodic-first square wave pulse without interphase delay, and 50 trains of pulse was applied with a period of 2 sec. Different electrical stimuli were applied. First, pulse amplitude was varied (voltage: $0.5{\sim}3.0V$). Second, pulse duration was varied $(100{\sim}1,200{\mu}s)$. Evoked responses were analyzed by PSTH from averaged data with 50 trials. Charge density was calculated with Ohm's and Coulomb's law. In normal retina, by varying the pulse amplitude from 0.5 to 3V with fixed duration of $500{\mu}s$, the threshold level for reliable ganglion cell response was found at 1.5V. The calculated threshold of charge density was $2.123mC/cm^2$. By varying the pulse duration from 100 to $1,200{\mu}s$ with fixed amplitude of 2V, the threshold level was found at $300{\mu}s$. The calculated threhold of charge density was $1.698mC/cm^2$. Even after the block of ON-pathway with L-(1)-2-amino-4-phosphonobutyric acid (APB), electrical stimulus evoked ganglion cell activities. In this APB-induced degenerate retina, by varying the pulse duration from 100 to $1200{\mu}s$ with fixed voltage of 2 V, the threshold level was found at $300{\mu}s$, which is the same with normal retina. More experiment with APB-induced degenerate retina is needed to make a clear comparison of threshold of charge density between normal and degenerate retina.