• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1657-1663
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• 2017

Cosmetic patches have recently been developed as skin products for personal care owing to rapid advances in the technology of delivery of active ingredients, moisture, and adhesiveness to skin. Alginate and Spirulina are typical marine resources used in cosmetic products. This research involved the development of a Spirulina extract-impregnated alginate nanofiber cosmetic patch supported by a polycaprolactone (PCL) nanofiber cover (Spi/Alg-PCL NF patch). In addition to the ability of alginate to affect moisture and adhesiveness to skin, the impregnation of Spirulina extract strengthened those abilities as well as its own bioactive effectiveness. All fabrication processing steps were undertaken in aqueous solution. The three components (alginate, Spirulina extract, and PCL) had no detected cytotoxicity in human keratinocyte cell-based examination. In addition, wetting the pre-dried patch on the skin resulted in the Spirulina extract being released within 30 min. The results indicate the excellence of the Spi/Alg-PCL NF patch as a skin-care cosmetic device.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.3 s.106
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• pp.295-306
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• 2006

In this paper, we proposed and implemented a novel antenna cover mounted over a microstrip path antenna for ultrafast aircraft. A protective antenna cover prevents alteration in the electrical characteristics of the antenna due to environmental conditions. The permittivity of the cover materials should be practically invariable at all operating frequencies. We evaluated the characteristics of the antenna with both simulation and experiment. The experimental results show that the proposed antenna cover can be useful for ultrafast aircraft.

• Journal of Environmental Impact Assessment
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• v.11 no.3
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• pp.117-127
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• 2002

This study tested the usefulness of landscape indices for quantifying forest fragmentation due to linear development projects. Research was carried out in the middle-upper Nakdong River watershed, which has been affected by the expressway building, or national road-widening. Landscape indices were calculated from the forest cover maps before and after road-building using FRAGSTATS 3.1. We could successfully demonstrate the forest fragmentation based on landscape indices; (1) patch size decreased, and edge density and patch density increased (2) roads simplified patch shapes, especially in the larger patches, (3) patch core area size decreased, and core area density increased, (4) the distance increased between the focal patch and each of the other patches within the search radius (=1km) as a result of roads. We suggest several important needs for future researches, including continued investigation of scaling issues, development of indices that measure specific components of spatial pattern, and study of the relationships between forest fragmentation and ecological processes.

• Journal of information and communication convergence engineering
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• v.16 no.3
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• pp.197-202
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• 2018

This paper reveals the impact of the insertion of electromagnetic band gap (EBG) structures on the performance of circularly polarized (CP) patch-slot antenna with offset slot. Several optimizations are necessary to precise physical parameters in the aim to fix the resonance frequency at 3.2 GHz. The proposed antenna possesses lightweight, simplicity, low cost, and circular polarization ensured by two feeding sources to permit right-hand and left-hand circular polarization process (RHCP and LHCP). The measured results compared with simulation results of the proposed circularly polarized EBG antenna with offset slot show good band operations with –10 dB impedance bandwidths of 9.1% and 36.2% centered at 3.2 GHz, which cover weather radar, surface ship radar, and some communications satellites bands. Our investigation will confirm the simulation and experimental results of the EBG antenna involving new EBG structures.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.6
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• pp.859-867
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• 2000

In order to analyze the effect of a cover layer or radome for an antenna, the moment method is applied to the analysis of the circular microstrip patch antenna with dielectric superstrate fed by coaxial probe. The probe feed is modeled as a attachment mode method which can solve more exact analysis. In case of a ideal probe feed modeling, the probe self-impedance as well as the rapidly-varying patch current at the vicinity of the feed point was neglected. But a rigorous probe feed model which overcomes these deficiencies are developed, and used in the analysis of isolated circular patches. Measurements were performed to validate the numerical results. These are good agreement with each other.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.4
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• pp.532-541
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• 2001

In the case of the microstrip antenna with the coaxial probe-feeding, there is rapidly-varying patch current near the point where the probe feed is connected to the patch. We represent this current distribution using the attachment mode that insures continuity of currents from the feed to the patch. In this paper, we can accurately analyze the effect of a cover layer or radome for an antenna with the attachment which model rigorous probe feed.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.3
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• pp.237-248
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• 1998

Landcover has been largely influenced by human activities, especially in recent days. The analysis of the change of land use by urbanized development is useful for determining development plan hereafter. This study aimed to the quantitative analysis about the urban sprawl within 12 years from 1985 to 1996, at Chonan, and for extracting the characteristics of change. For this purpose, this study performed land cover classifications using Landsat TM data . A hybrid classification method was used to classify satellite images into seven types of land cover. Road network digitied from 1:25,000 topographic map was rasterized and overlaid on the landcover map. A result of this study showed that area of forest and paddy decreased due to urban sprawl. Especially from 1993 to 1996, the change of land use progressed rapidly because of merging a city and a country in Chonan. The size of patch in forest had been smaller and irregular form. It is a general progress that size of patch in forest had been smaller and irregular form. It is a general progress that the forest have changed the paddy and bare land paddy and bare land have changed low-density urban or high-density urban. This explained how urbanized Chonan was and applied the suggeston of plan in landuse with the result of this study.

• Journal of Advanced Navigation Technology
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• v.20 no.1
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• pp.93-98
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• 2016

The purpose of this study is to design for MOB antenna attached on safety helmet using microstrip patch antenna. The patch antenna is fabricated in 0.2 mm FR-4 substrate with $64{\times}64mm$ size. The proposed antenna is based on a slot-ring design which cover Inmarsat (1.52 ~ 1.65 GHz) and GPS (1.575 GHz) frequency band. To obtain the optimized parameters, HFSS simulator is used, and antenna is designed by optimized parameters. After antenna was etched, SMA connector was attached to the microstrip feeding line and the result between antenna simulation and measurement was analyzed. Proposed antenna is satisfied the -10 dB bandwidth requirement while simultaneously covering the 1.53 ~ 1.65 GHz.

• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.690-700
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• 2008

The Soil and Water Assessment Tool (SWAT) model users tend to use the readily available input dataset, such as the Ministry of Environment (MOE) land cover data ignoring temporal and spatial changes in land cover. The SWAT model was calibrated and validated with this land cover data. The EI values were 0.79 and 0.85 for streamflow calibration and validation, respectively. The EI were 0.79 and 0.86 for sediment calibration and validation, respectively. With newly prepared landcover dataset for the Doam-dam watershed, the SWAT model better predicts hydrologic and sediment behaviors. The number of HRUs with new land cover data increased by 70.2% compared with that with the MOE land cover, indicating better representation of small-sized agricultural field boundaries. The SWAT estimated annual average sediment yield with the MOE land cover data was 61.8 ton/ha/year for the Doam-dam watershed, while 36.2 ton/ha/year (70.7% difference) of annual sediment yield with new land cover data. Especially the most significant difference in estimated sediment yield was 548.0% for the subwatershed #2. Therefore it is recommended that one needs to carefully validate land cover for the study watershed for accurate hydrologic and sediment simulation with the SWAT model.

• Journal of Environmental Science International
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• v.30 no.10
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• pp.779-787
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• 2021

This study analyzes structural landscape changes over a time-series for a small and medium-sized city, Gangneung-Si, based on area and distribution patterns, and according to the type of land cover. Among the types of land cover, the area ratio of urbanized areas increased by 2.02% in the late 2010s as compared to the late 1980s, while there was a decrease of 2.69% in farmland and 0.69% in grassland areas. On analyzing the changes in land cover use by applying the Fragstats program, it was confirmed that landscape changes in urban and management areas were relatively severe according to the Landscape Shape Index, Largest Patch Index, and Aggregation Index. A pattern of concentrated expansion was also found around certain areas. In particular, from the analysis, it was established that the proportion of urbanized area had considerably increased and that the extent of farmland damage to management areas, including planned management areas, was large. Additionally, the Total Core Area generally indicated a reduction in the core areas of farmland and forest within urban and management areas. A medium-sized city showed significant changes besides large cities in terms of landscape structure. The developmental pressure on management areas, in particular, was quite high.