• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.267-270
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• 1999

Use of coherence data from operational satellite based SAR sensors has been experimented both on C and L band to identify landcover in tropics. While coherence data proved useful to improve accuracy in landcover identification, such data are not readily available. On the other hand, integrated use of backcatter data by multiple satellites is readily feasible. The very question to be asked is whether integration of backscatter data on multiple bands (e.g. C and L band) is either inferior or superior to use of coherence data. We therefore still do not have a solid clue to answer to the very question. The aim of this study is to evaluate the performance of "integrated use" of backscatter data on C and L band (by ERS and JERS respectively) to identify landcover, vis-a-vis the same by combination of backscatter and coherence data by single satellite. The study was carried out for an area in the southern part of the Sumatra Island, Indonesia. The area has been intensively converted from natural forest into plantation. Five categories of landcover exist in this study area. By ERS-1, only 2 or 3 classes may be identified with the backscatter data alone, while adding the coherence data could delineate 4 classes. By JERS-1, only 3 to 4 classes may be identified with the backscatter data alone, while 4 classes could be clearly delineated by adding the coherence data. By integrating backscatter data on two bands, 4 to 5 classes may be identified. It represents the best results among cases examined. The outcome of the study suggests that integrated use of backscatter data on two bands by ERS and JERS is as powerful as use of backscatter and coherence data on single band by one of these satellite.

• The Korean Journal of Zoology
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• v.39 no.3
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• pp.325-336
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• 1996

Community organization of the drosophilid flies was investigated with respect to the seasonal variation in species abundance and vertical microdistribution on the basis of the trapped collections in the two natural forests on Cheju-do from May to October 1994. The dominant species were Drosophila bizonata, D. curviceps, D. lutescens, D. angu leris, D. tsigana and D. immigrans in the annual collections. The pattern in seasonal changes of the dominant species was similar at the two survey sites. Seasonal fluctuation in the species diversity was more affected by evenness than by species richness (number of species). The seasonal variation of abundance showed an unimodal pattern in all of the dominant species. The seasonal patterns of vertical microdistribution revealed difference in some of the dominant species between the two survey sites. These results suggest that the predominant species in the forest avoid niche overlap by means of seasonal separation of breedings and that the vertical microdistribution is strongly affected by factors associated with season and vertical site in the deep wooded forests.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.6
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• pp.1-11
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• 2010

The purpose of this research is to identify satisfaction levels of the arboretum which will be provided in the Multifunctional Administrative City and to estimate the economic value of using choice experiments. The attributes were "Preservation", "Education", "Recreation", "Facility", "Accessibility" and the entrance fee. The main effects model was utilized to construct hypothetical alternatives. Calibration of the conjoint choice model revealed that 'wetlands' and 'forest trails' in "Preservation" and the "Recreation", respectively, were significant variables. This result indicates that respondents are willing to pay more for these if they are provided in the arboretum. Also, 'variety seeking' tendency, age, and income level positively influenced the provision of the arboretum. Involvement in preservation of natural environment, however, had a negative influence on the establishment of the arboretum. Because this study is the first attempt to estimate the economic valuation of an urban arboretum using choice experiment, there are several suggestions for future research in terms of determining the base level and inclusion of salient attribute levels.

• Journal of Ecology and Environment
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• v.33 no.1
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• pp.47-57
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• 2010

To understand day-to-day fluctuations in soil moisture content in Seoul, I simulated daily soil moisture content from 1908 to 2009 using long-term climatic precipitation and temperature data collected at the Surface Synoptic Meteorological Station in Seoul for the last 98 years with a hydrological simulation model, BROOK. The output data set from the BROOK model allowed me to examine day-to-day fluctuations and the severity and duration of droughts in the Seoul area. Although the soil moisture content is highly dependent on the occurrence of precipitation, the pattern of changes in daily soil moisture content was clearly quite different from that of precipitation. Generally, there were several phases in the dynamics of daily soil moisture content. The period from mid-May to late June can be categorized as the initial period of decreasing soil moisture content. With the initiation of the monsoon season in late June, soil moisture content sharply increases until mid-July. From the termination of the rainy season in mid-July, daily soil moisture content decreases again. Highly stochastic events of typhoons from late June to October bring large amount of rain to the Korean peninsula, culminating in late August, and increase the soil moisture content again from late August to early September. From early September until early October, another sharp decrease in soil moisture content was observed. The period from early October to mid-May of the next year can be categorized as a recharging period when soil moisture content shows an increasing trend. It is interesting to note that no statistically significant increase in mean annual soil moisture content in Seoul, Korea was observed over the last 98 years. By simulating daily soil moisture content, I was also able to reconstruct drought phenomena to understand the severity and duration of droughts in Seoul area. During the period from 1908 to 2009, droughts in the years 1913, 1979, 1939, and 2006 were categorized as 'severe' and those in 1988 and 1982 were categorized as 'extreme'. This information provides ecologists with further potential to interpret natural phenomenon, including tree growth and the decline of tree species in Korea.

• Journal of Environmental Science International
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• v.18 no.6
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• pp.633-644
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• 2009

The vascular plants in the Gyeryongsan National Park were listed 227 taxa; 71 families, 148 genera, 196 species, 1 subspecies, 26 varieties and 4 forms, Among them, trees and herbs were 103 taxa (45.4%), 124 taxa (54.6%), respectively. The rare plants were identified 6 taxa such as Paeonia obovata (Legal protection species), Viola albida, Acanthopanax chiisanensis, Lilium distichum, Lilium callosum and Goodyera schlechtendaliana by the Korea Forest Service. Based on the list of Korean endemic plants, 8 taxa were recorded; Cephalotaxus koreana, Pseudostellaria multiflora, Thalictrum uchiyamai, Indigofera koreana, Acanthopanax chiisanensis, Asperula lasiantha, Weigela subsessilis and Carex okamotoi. Based on the list of approved for delivering overseas of plants, 6 taxa were recorded; Viola albida, Acanthopanax chiisanensis, Asperula lasiantha, Carex okamotoi, Lilium distichum and Lilium callosum. Specific plant species by floral region were total 21 taxa (9.3%); Paeonia obovata in class V, 5 taxa (Betula davurica, Acer palmatum, Asperula lasiantha, Lonicera subhispida, Phaenosperma globosa) in class III, 4 taxa (Viola orientalis, Acanthopanax chiisanensis, Ostericum melanotilingia, Lilium distichum) in class II and 11 taxa (Cephalotaxus koreana, Betula schmidtii, Quercus variabilis, Aphananthe aspera, Ilex macropoda, Meliosma oldhamii, Tilia amurensis, Lilium callosum, Erythronium japonicum, Polygonatum inflatum, Hosta capitata) in class I. It is important that relationship between national and local government will be needed for preservation of natural environment of Gyeryongsan National Park. As well, a long time of monitering and systematical management counterplan will be required.

• Journal of Environmental Science International
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• v.23 no.8
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• pp.1523-1536
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• 2014

Restoration is the process of reducing or reversing damage to an ecosystem so that it can function in its original manner. However, many restoration programs do not achieve this. In the Nakdong Estuary, the largest migratory nesting site in the center of the East Asian-Australasian flyway, an estuarine barrage was constructed in the 1980s that required site restoration following its completion in 1987 and the expansion of several large industrial complexes(Noksan and Jangrim) and a residential development(Myeongji). The goal of the restoration was to restore the function of the wetland to its pre-disturbance state. To achieve this, a restoration program was designed consisting of three stages. The first stage(1993-1995), saw the construction of three artificial wetlands(Shinhori, Daemadeung, and Eulsuk), the second(2003-2005) involved the dredging and returning of farmed lands to their natural state, and the third(2008-2012) focused on the rehabilitation and vegetation development of the wetlands. However, the project has not achieved all of the desired goals, and it is an example of the lapses in ecological restoration following anthropogenic disturbance. Issues that resulted in an incomplete restoration included the timing of the stages, noncompliance with the restoration plan, not directly monitoring the restoration or continuing the monitoring following completion of the development project, and the political subversion of the restoration plan. For the success of the restoration plan, it is necessary to avoid mistakes such as inconsistent monitoring, unequal levels of stakeholder involvement, and political interference.

• Natural Product Sciences
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• v.22 no.4
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• pp.299-306
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• 2016

This study aimed to establish the quantitative method to analyze the content of peroxynitrite-scavengers belonging to polyphenols in six Korean Quercus species (Quercus mongolica, Q. dentata, Q. acutissima, Q. alienta, Q. serrata, and Q. variabilis) by HPLC. The twelve peroxynitrite-scavengers, flavanols (catechins: (+)-catechin, (-)-epicatechin, and (-)-epigallocatechin), flavonols (kaempferol and quercetin), flavonol glycosides (astragalin, quercitrin, and isoquercitrin), flavonol acylated glycosides (astragalin 6''-gallate and isoquercitrin 6''-gallate), gallic acid and its dimer (ellagic acid) were analyzed by HPLC. Further, anti-Alzheimer's activity was assayed in a passive avoidance testusing mice by measuring the retention latency (sec), the concentration of acetylcholine (ACh), and acetylcholinesterase (AChE) activity. Simultaneous analysis of the extracts of the six Quercus leaves was achieved on a Capcell C18 column ($5{\mu}m$, $250mm{\times}4.6mm\;i.d.$) with a gradient elution of 0.05% HAc and 0.05% HAc in $CH_3CN$. In the extract of Q. mongolica leaves, the content of gallic acid (32.53 mg/g), (+)-catechin (28.78 mg/g), (-)-epicatehin (22.03 mg/g), astragalin 6''-gallate (20.94 mg/g), and isoquercitrin 6''-gallate (44.11 mg/g) and peroxynitrite-scavenging activity ($IC_{50}$, $0.831{\mu}g/ml$) were high. This extract delayed the retention latency and inhibited acetylcholinesterase activity in scopolamine-induced memory impairment of mice, suggesting that it has anti-Alzheimer's activity.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.2
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• pp.11-25
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• 2001

A wetland is an ecosystem which is the most useful and highly-energetic transition area. This study has been carried out to classify and identify the various types of wetlands in Korea. The main objective of this study are 1) defining and classifying of wetlands, and 2) identifying the wetlands characteristics, and 3) studying cases on the natural wetlands such as Han river, DMZ(Demillitarized Zone), Upo wetland and Yong(Dragon) wetland. The results as follows： 1) Development of the indices for identifying and classifying wetlands in encompassing in such as Ramsar Conference, US NWI(National Wetlands Inventory), Hydrogeomorphic system. 2) Development on the classifying method on the wetlands in the level of supersystem, system, subsystem, class and subclass. The systems include Palustrine and Riverine, and the subsystems are Seasonal, Permanent(Palustrine) and Impersistent, Lower perennial, Impersistent (Riverine). 3) Finally, we find out Young wetland is Palustrine/Permanent/Slope/Persistent, and Upo wetland consists of various types of wetlands, those are, Palustrine/Permanent/Depression/Forest Deciduous, Palustrine/Permanent/Depression/Shrub Deciduous, Palustrine/Permanent/Depression/Persistent, Palustrine /Permanent/Depression/Hydrophytes, and Lacustrine/Permanent/Openwater/Hydrophytes. The taxonomy of this study stems from identifying and classifying wetlands with indices mainly based on hydrologic features and substrates. So, it is needed that consequent studies are to be performed with various viewpoints. And the studying cases were limited because of the restricted entrance into the DMZ, And, we selected only 10 crucial sites in Han river as the subject for wetlands regulation and creation. And, for advanced studies, drawing up inventory and mapping are necessary.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.2
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• pp.20-27
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• 2016

Ethylene gas is a natural hormone that directly affects the freshness of agricultural products, so it is very important for the maintenance of freshness to remove ethylene gas from corrugated board boxes. Many methods for the removal of this and other gases have been reported. In this study, the utilization of an absorbent using activated carbon was adopted for the removal of ethylene gas from a corrugated board box. Activated carbon powders were prepared by grinding in a laboratory and were used to treat the surface and to laminate paperboards with a starch solution. The ethylene gas absorption was evaluated by using a gas chromatography to measure the residual ethylene gas concentration. About 60% of the ethylene gas was absorbed by the activated carbon itself. However, the paperboards that were surface-treated and laminated with starch and activated carbon showed lower than 20% ethylene gas absorption. This was because the starch and smaller particles of activated carbon blocked the surface pores of activated carbon particles. Therefore, either the use of the binders must be minimized for the surface treatment of paperboards, or activated carbon packs can be used as absorbents in corrugated boxes.

• Journal of the Korean Society of Safety
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• v.35 no.2
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• pp.84-93
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• 2020

In recent years, the scale of damage from disasters such as earthquakes and large-scale fires and floods that are occurring in Korea is increasing. Accordingly, interest in urban disaster prevention that combines living infrastructure such as roads and parks is boosting, and it is urgent to prepare measures to reduce the damage scale of local cities. The purpose of this study is to derive implications for disaster prevention measures in areas where disaster prevention safety of local cities is weak through examples of disaster prevention safety of local cities in case of disaster. To this end, this study analyzed the regional characteristics, current status, and disaster prevention problems of regional cities in Japan, and selected disaster-vulnerable areas, and considered the distance relationship between disaster prevention bases through road network analysis. In addition, road closure simulation using ArcGIS Network Analyst was conducted to analyze disaster prevention safety in the area. As a result, the situation of the village which has a high possibility of isolation by natural disasters was grasped in advance. Through this, the suburbs confirmed the necessity of supplementing the disaster prevention function through transportation maintenance such as forest roads, and it was found that the city needs to prepare a risk management system. Furthermore, this study suggests the need for research on areas with a high possibility of isolation, especially in areas where disaster prevention functions are weak in local cities in case of disaster, and shows countermeasures for disaster prevention measures and resident education.