• Journal of the Korean Wood Science and Technology
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• v.15 no.4
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• pp.45-58
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• 1987

This study was carried out to improve the physical and mechanical properties of Pupulus alba $\times$ glandulosa treated by the heat and compression. The results obtained were as follows. 1. The specific gravity of the wood was conspicuously increased by the lincreasing of pressing level. 2. The shrinkage of the wood was increased. by the increasing of pressing level. The radial shrinkage was 6.41-8.81%, the tangential shrinkage was 8.98-19.81 %, and the longitudinal shrinkage was 1.46-1.91 %. Comparing to the untreated stock, the rate of increase was 48.7-104.4% in radial direction. 1.7-124.4% in tangential direction and 60.4-109.9% in longitudinal direction, respectively. 3. The rate absorption of 30% compressed stock was Similar to that of untreated stock. but the rate of absorption of 40 % or more compressed stock was increased highly. 4. The thickness swelling of the wood was not changed in radial direction at pressing level, but was conspicuously increased in tangential direction under the pressing level of 40% and 50%. 5. The heat and compression treatment affected on the mechanical properties of the wood. The longitudinal compressive strength was increased under the pressing level of up to 40%, but was decreased under the pressing level of 50%. The bending strength was not changed under the compression percentage of up to 30%, but was decreased under the pressing level of 30% or more. And, the absorbed energy in impact bending was increased to 128% under the pressing level of up to 30%, but was decreased under the pressing level of 30% or more. Conclusionly, the mechanical properties of the wood was improved by the heat and compression treatment, but the strength of the wood was decreased under the pressing level of a certain level or more(in this study, pressing level of 30% or more). This was because of the wood deterioration due to the deformation(shrinkage, crack, failure) of wood tissues induced by the heat and compression treatment, the heat analysis of wood components induced by the heating, and the drop of the degree of polymerization.

• The Korean Journal of Petroleum Geology
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• v.4 no.1_2 s.5
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• pp.27-39
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• 1996

In the Cretaceous, the Gulf Coast Basin evolved as a marginal sag basin. Thick clastic and carbonate sequences cover the disturbed and diapirically deformed salt layer. In the Cretaceous the salinities of the Gulf Coast Basin probably matched the Holocene Persian Gulf, as is evidenced by the widespread development of supratidal anhydrite. The major Lower Cretaceous reservoir formations are the Cotton Valley, Hosston, Travis Peak siliciclastics, and Sligo, Trinity (Pine Island, Pearsall, Glen Rose), Edwards, Georgetown/Buda carbonates. Source rocks are down-dip offshore marine shales and marls, and seals are either up-dip shales, dense limestones, or evaporites. During this period, the entire Gulf Basin was a shallow sea which to the end of Cretaceous had been rimmed to the southwest by shallow marine carbonates while fine-grained terrigengus clastics were deposited on the northern and western margins of the basin. The main Upper Cretaceous reservoir groups of the Gulf Coast, which were deposited in the period of a major sea level .rise with the resulting deep water conditions, are Woodbinefruscaloosa sands, Austin chalk and carbonates, Taylor and Navarro sandstones. Source rocks are down-dip offshore shales and seals are up-dip shales. Major trap types of the Lower and Upper Cretaceous include salt-related anticlines from low relief pillows to complex salt diapirs. Growth fault structures with rollover anticlines on downthrown fault blocks are significant Gulf Coast traps. Permeability barriers, up-dip pinch-out sand bodies, and unconformity truncations also play a key role in oil exploration from the Cretaceous Gulf Coast reservoirs. The sedimentary sequences of the major Cretaceous reseuoir rocks are a good match to the regressional phases on the global sea level cuwe, suggesting that the Cretaceous Gulf Coast sedimentary stratigraphy relatively well reflects a response to eustatic sea level change throughout its history. Thus, of the three main factors controlling sedimentation (tectonic subsidence, sediment input, and eustatic sea level change) in the Gulf Coast Basin, sea-level ranks first in the period.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.403-408
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• 2017

This study aims to set up the basic data to manage the waterfowl habitat through the analysis of the changes of physical structure according to the time series of Hangang(Riv.) as water birds' habitat. Study area was 41.5km in length from Paldang bridge to Hangju bridge. during total length of 497.52km and horizontal boundary was based on the protected lowland in year 1975. As the analysis result of land use from the center of water to adjacent road to the river, ratio of year 1975 was in order of sedimentary land(22.7%), surface water(20.7%), built-up area(16.9%), field(16.2%), paddy field(15.9%), and afterwards most of the areas were changed through the construction of arterial highway and submerged weir in order to use Hangang(Riv.). In year 1985, the area ratio of protected lowland(57.8%) and surface water(32.8%) dramatically increased. After construction of river bank the recreational areas continually increased and relatively natural areas decreased. In year 2005, the area ratio of protected lowland was enlarged to 57.6% and surface water also to 33.3%. While the length of both riversides and naturalness decreased by 10.9%, 91.5% respectively in year 2005 compared to year 1975, the depth of water increased by 1.46m. Comprehensively, the flow of changes by physical structure in Hangang(Riv.) for 30 years was divided into two periods. The main characteristics in the first period were decrease of riverside area and enlargement of the surface water through the massive construction before middle of year 1980, and afterwards revetments were intensively artificialized with changes of land use for amusement area. In terms of water fowl habitat, Hangang(Riv.) which previously had various types of habitat condition was changed into simplified habitat for few of species, and the active improvement apporach was needed for habitat diversity.

• The Journal of the Petrological Society of Korea
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• v.28 no.4
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• pp.319-345
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• 2019

Recently planification and effort for management, assessment and discovery of geological heritagesare being increasingly demanded with institutional strategies such as geopark, as their preservation is asked socially. In this study, we discovered geological heritages in the Jeolla Province and then performed assessment of the value and grading of them and finally suggested a promising and suitable site for the National Geopark. A total of 325 geological heritages are listed on literature review and then detailed description in field and assessment of the value for selected 158 geoheritages are completed. The assessment items are categorized into intrinsic value, subsidiary value, and preservation/management part. The intrinsic value is subdivided into scientific/educational value, composed of representativeness, rarity, geodiversity, typicality, reproducibility, and particularity, and geomorphological/landscape value composed of scale, naturality (integrity), scenery (aesthetic value). Also, subsidiary value consist of 7 subsections of soil function, ecological function, tourism value, geological resource, historical value, folk tale or legend and symbolic value, and accessibility, convenient facility (infrastructure), management condition (legal protection) is evaluated in preservation/management part. The heritages in the Jeolla Province subdivided into three types: 73 geological heritages, 42 geomorphological heritages, and 42 composite heritages. Based on points acquired in intrinsic value, all geological heritages are graded Class-I to -V. As a result, numbers of geoheritage belong to Class-I (protection at world level), -II (protection at national level), -III (nationdesignated management), -IV (involved management list), -V (candidate management list) are 12, 39, 52, 34, 21, respectively. Finally, we construct database based on Arc-GIS with all informations for each geological heritage and suggest three promising and suitable sites, 'Jirisan-Seomjingang Area' and 'south coast area of Jeolla Province', for the National Geopark.

• Korean Journal of Environment and Ecology
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• v.24 no.3
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• pp.249-257
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• 2010

The purpose of this paper is to weigh the possibility of endangered Jang-hang wetland at the estuary of Han River to be included on the Ramsar List of Wetlands of International Importance and come up with ways to manage the wetland depending on its biotope patterns. The target area is located between Gimpo bridge and Isanpo I.C. with about $2.7km^2$ area. Through the analysis of RIS(Information Sheet for Ramsar Wetlands), it was known that the wetland is located on the sedimentary topography and formed as a result of sediment at the estuary of the river owing to the concentration of rainfall during summer. The vegetation environment in the area is divided into brackish water and fresh water areas depending on salinity. Rhizosphere soil(RS) of the area was analyzed to be Silt loam while bottom RS to be Sand loam. The plant ecology was composed of 52 families 135 species and 11 varieties and 146 types. Among indigenous species found are Salix koreensis, Phragmites communis and Miscanthus sacchariflorus. The analyzed results of the actual vegetation showed that willow community accounts for 37% of the area and rice field is 13.5%. As for animal ecology, total of 62 species and 25,977 individual wild birds were observed. After comparing and analyzing the RIS we compiled with the Ramsar Site designation standards, it turns out that the Jang-hang wetland meets criteria 1(biographic region), criteria 2,3 and 4(species and ecological communities) and criteria 5 and 6(water birds). Thus, Jang-hang wetland is eligible for the Ramsar site. As a result of establishing and evaluating the biotope types for setting management areas, Jang-hang wetland has a total of 13 different types, and the grade I represents 75.4% of the area while the grade III 0.8% of the land status. We categorized four management zones for the wetland depending on the biotope patterns - preservation, restoration, use and buffer zones and suggested management methods for each zone.

• The Korean Journal of Petroleum Geology
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• v.6 no.1_2 s.7
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• pp.20-24
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• 1998

Expert system is one type of artificial intelligence softwares that incorporate problem-solving knowledges and experiences of human experts by use of symbolic reasoning and rules about a specific topic. In this study, an expert system, PLAYMAKER2, is used to interpret sedimentary facies and depositional settings of the sedimentary sequence. The original version of the expert system, PLAYMAKER, was developed in University of South Carolina in 1990, and modified into the present PLAYMAKER2 with some changes in the knowledge-base of the previous system. The late Cenozoic sedimentary sequence with maximum 10,000 m in thickness, which is located in the Korean Oil Exploration Block VI-1 at the southwestern margin of the Ulleung Basin, is analysed by the expert system, PLAYMAKER2. The Cenozoic sedimentary sequence is divided into two units-lower Miocene and upper Pliocene-Pleistocene sediments. The depositional settings and sedimentary facies of the Miocene sediments interpreted by PLAYMAKER2 in terms of belief values are: for depositional settings, slope; $57.4\%$, shelf; $21.4\%$, basin; $10.1\%$, and for sedimentary facies, submarine fan; $35.7\%$, continental slope; $26.3\%$, delta; $16.1\%$, deep basinplain; $6.1\%$ continental shelf; $3.2\%$, shelf margin; $1.4\%$. The depositional settings and sedimentary facies of the Pliocene-Pleistocene sediments in terms of belief values we: for depositional settings, slope; $59.0\%$, shelf; $22.8\%$, basin; $7.0\%$, and for sedimentary facies, delta; $24.1\%$, continental slope; $22.2\%$, submarine fan; $17.3\%$, continental shelf; $7.0\%$, deep basinplain; $4.8\%$, shelf margin; $2.6\%$. The comparison of the depositional settings and sedimentary facies consulted by PLAYMAKER2 with those of the classical interpretation from previous studies shows resonable similarity for the both sedimentary units-the lower Miocene sediments and the upper Pliocene-Pleistocene sediments. It demonstrates that PLAYMAKER2 is an efficient tool to interpret the depositional setting and sedimentary facies for sediments. However, to be a more reliable system, many sedimentologists should work to refine and add geological rules in the knowledge-base of the expert system, PLAYMAKER2.

• Economic and Environmental Geology
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• v.39 no.1 s.176
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• pp.83-93
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• 2006

The Kita-Yamato Trough is characterized by a SW-NE trending narrow graben between the Yamato Bank and the Kita-Yamato Bank in the central East Sea/Japan Sea (ES/JS). Core 20EEZ-1 was obtained in the flat summit of a small ridge from the southwest Kita-Yamato Trough. The sedimentation was mainly controlled by the supply of hemipelgic sediments and substantial tephras from explosive volcanic eruptions of the Quaternary volcanoes. The aim of this study is to reconstruct the tephrostratigraphy from the marine sediments collected from the Kita-Yamato Trough and to provide the atmosphere and ocean conditions during the explosive volcanic eruptions. According to the detailed tephrostratigraphy and lithofacies records, the core sediments were deposited during the last marine isotope stage (MIS) 7. The core consists of four lithofacies, idetified as, oxidized mud (OM), crudely laminated mud (CLM) and bioturbated mud (BM), interbedded with coarse-grained tephra (TP). The major element geochemistry and stratigraphic positions of seven tephra layers suggest that they originated from the Aira caldera in Kyushu area among the Japanese islands (AT tephra; 29.24 ka), unknown submarine volcano in the south Korea Plateau (SKP-I; MIS 3, SKP-II; MIS 4, SKP-IV; boundary between MIS 6 and MIS 5e, SKP-V; MIS 6, respectively), and the Baegdusan volcano in the Korean Peninsula (B-KY1; ca. 130 ka, B-KY2; ca. 196 ka). The absence of tephras originated trom Ulleung Island in core 20EEZ-l suggest that the tephras had not been transported into the Kita-Yamato Trough by atmosphere conditions during the eruptions. On the other hand, the B-KYI and the B-KY2 tephras derived from the Baegdusan volcano were founded in the Kita-Yamato Trough by a presence of prevailing westerly winds during the eruptions. Furthermore, the SKP tephras were characterized by the transport across the air-water interface, causing quickly thrust of raising eruption plumes from subaqueous explosive eruptions. Surface currents may play an important role in controlling the distribution patterns of the SKP tephras to distal areas. The tephrostratigraphic study in the Kita-Yamato Trough provides the important chronostratigraphic marker horizons and the detailed atmosphere and ocean conditions during the explosive eruptions.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.2
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• pp.175-183
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• 2010

To understand the variation of macro benthos community according to the installation of structure and topographic placement in the shellfish farm on tidal flat, the practical example of the tidal shellfish growing area at Namsung-ri Goheung was observed. The results of the research for the field observation were summarized as follows. (1) The ground gradient of the shellfish farm was very flat below about $1^{\circ}$. The shellfish farm ground took the shape of $\sqcup$ from the shoreline to the place of 150 m seawards, and the shape of $\sqcap$ from there to the low tide line. During ebb tide, the $\sqcup$ shape ground stored the sea water, and the $\sqcap$ shape ground was supposed to act as the effect factor to leak slowly or to prevent the outflow. (2) The oyster shell bag or the type of riprap wall as the boundary in the shellfish farm was classified into five types. The air exposure time and flooding time were 181 and 434 minutes, respectively. (3) In the numerical experiment, the deep-sea water wave coming in the study area had 0.5 m of maximum wave height to show the very stable conditions and the wave direction pattern of S-direction was dominant at Naro great ridge, and SE, SSW and S-direction were distributed strongly around the shellfish farm. (4) By the grain size analysis, the sediment around tidal flat consisted of gravel 0.00~5.81(average 1.70)%, sand 14.15~18.39(average 13.23)%, silt 27.59~47.15(average 30.84)% and clay 35.79~55.73(average 36.19)%, and the sediment type was divided into (g)M(lightly gravelly mud), sM(sandy mud) and gM(gravelly mud) by Folk's diagram. (5) The macro benthos community survey conducted in this site in January, 2010 showed that 1 species of Mollusca, 8 species of Polychaeta and 2 species of Crustacea appeared, and 11 species occupying over 1% of total abundance were dominant.

• Journal of the Korean Wood Science and Technology
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• v.15 no.2
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• pp.1-15
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• 1987

This experiment was undertaken for the purpose of investigation of relative durability about thirty sorts of the korean native wood and nine sorts of the wood destroying fungi Polystictus versicolor, Irpex consors. Poria vaporaria, Merulius lacrymans, Schizophyllum commune, Trametes pini, Lenzites betulina, Paxillus panuoides by means of a laboratory methods. The results obtained are; (from the table 2 to 10) 1. By measuring the percentage of loss in weight with regard to Polystictus versicolor, the sap wood contained in Junipeus chinesis was calculated at 18.2%, therefore it is much higher durability than any others and the sap wood contained in Pinus densiflora was measured at 44.10%, therefore it is much lower durability than any others. 2. By measuring the percentage of loss in weight with regard to Irpex consors, the heart wood contained in Butula schmidtii was calculated at 1.23%, therefore durability is very high and the heart wood contained in Quercus dentata was calculated at 26.79%, therefore durability is very low. 3. By measuring the percentage of lass in weight with regard to Lenzites betulina, the heart wood contained in Betula schmidtii was calculated at 5.33%, therefore it is much higher durability than any others and the sap wood with regard to Abies holophylla was measured at 45.48%, therefore durability is very low. 4. By measuring the percentage of loss in weight with regard to Poria vaporaria, the sap wood contained in Fraxinus rhynchophylla was calculated at 5.57%, therefore durability is very high and the sap wood contained in Paulownia coreana was calculated at 35.6%, therefore it is much lower durability than any others. 5. By measuring the percentage of loss in weight with regard to Merulius lacrymans, the heart wood contained in Castanea crenata was measured at 0.09% and in the next place, the heart wood contained in Abies holophylla calculated at 0.15% did not decay almost and the sap wood contained in Cornus controversa was measured at 32.88%, therefore it is lower durability than any others. 6. By measuring the percentage of loss in weight with regard to Schizophyllum commune, the sap wood cantained in Junipensis chinensis was calculated at 1.09%, therefore durability is very high and the sap wood contained in Populus deltoides was calculated at 36.87%, it is much lower durability than any others. 7. By measuring the percentage of loss ill weight with regard to Trametes pini, the sap wood contained in Robinia pseudo-acacia was calculated at 1.33%, therefore durability is very high and the sap wood contained in Comus controversa was calculated at 33.19%, it is much lower durability than any others. 8. By measuring the percentage of loss ill weight with regard to Paxillus panuoides. the heart wood contained in Zelkova serrata was calculated at 1.73%, therefore durability is very high and the sap wood contained in Populus deltoides was calculated at 42.30%, therefore durability in very low. 9. By measuring the percentage of loss in weight with regard to Dardalea quercina, the heart wood contained in Castanea crenata was calculated at 0.92%, therefore durability is very high and the sap wood contained in Cornus controversa was calculated at 32.00% therefore durability is very low. The above results are summarized as follows 1. Durability between the heart wood and the soft wood find that it is nonsignificant, while durability is higher heart wood than sap wood. 2. Special sorts including in the element like Castanea cenata, Robinia pseudo-acacia, Juniperus chinensis and heart wood like Betula schmiditii and Styrax obasia are highly durable and soft wood like Cornus controversa, Populus davidiana, Salix koreensis, Celtis jessensis are lowly durable in general. 3. Among the wood destroying fungi Paxillus panuoides is highly durable and as follows. Poria vaporaria, Lenzites betulina and the Daedalea quercina is less in general and Irpex consors, Mersulius lacrymans are a middle degree.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.493-512
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• 2019

The purpose of this study was to provide the basic data necessary for establishing a vegetation management plan for the Yeongcheon River area by presenting a better understanding of the distribution and characteristics of naturalized plants through an investigation of the flora present in the Yeongcheon riverside, in Jinju, South Korea. Vascular plants were investigated for a total of 470 taxa, including 90 families, 282 genera, 425 species, one sub-species, 38 varieties, and six forms. Together, these accounted for 9.62% of the vascular plants (4,881 species) in Korea. Gramineae was the most abundant at 77 taxa (16.38%), followed by Cyperaceae at 56 taxa (11.91%), Leguminosae at 33 taxa (7.02%), Cyperaceae at 25 taxa (5.32%), and Rosaceae at 22 taxa (4.86%). Thirty species of indicator plants were surveyed and, among them, annual plants and hemicryptophytes accounted for a significantpercentage. Among ground plants, trees, shrubs, and sub-shrubs were surveyed to include 23 (4.89%), 17 (3.61%), and 14 taxa (2.97%), respectively. Furthermore, 36 aquatic plant taxa were found. Six rare plant taxa were surveyed including Penthorum chinense, Melothria japonica, Aristolochia contorta, Acorus calamus, Millettia japonica, and Magnolia kobus. Floristic special plants comprised 35 taxa,including 26 families, 34 genera, 34 species, and one variety. Plants endemic to Korea included six species. Naturalized plant species comprised 71 taxa, including 18 families, 53 genera, 68 species, and three varieties. The naturalization rate and urbanization index were 15.1% and 22.1%, respectively. Ecological disturbance species in Korea comprised nine taxa, including four families, eight genera, eight species, and one variety. These groups accounted for 64% of the ecological disturbance species in Korea. Ecological disturbance species in Korea tended to increase toward the downstream of Yeongcheon River. In particular, Ambrosia artemisiifolia and Sicyos angulatus, which cause human allergies and disrupt the habitats of plants and animals, must be removed artificially.