• The Korean Journal of Ecology
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• v.28 no.3
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• pp.149-156
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• 2005

This study was conducted to elucidate the relationship between the aboveground vegetation structure and fine roots of the topsoil (<15m), and thereafter to obtain the regression models for the estimation of the fine roots of the topsoil using the aboveground vegetation values in the burned forest areas, Korea. The FRT (fine roots of the top soil) as well as the aboveground vegetation structure showed spatial variation in the earlier successional stages after forest fire. The fine roots (<2 mm) of the topsoil in the earlier successional stages than the first 3 year after forest fire showed the range from 3 to 166 g $DM/m^2$. The FRT in the naturally regenerated sites and planted sites after forest fire was closely correlated with the vegetation indices, especially lvc, representing the development status of the aboveground vegetation. The FRT in the terrace seeding work sites after forest fire was closely correlated with year elapsed after terrace seeding work. The FRT in the terrace seeding work sites showed the much higher values because of the vigorous growth of grass species than the other sites. In the naturally regenerated sites, the FRT showed the parabola form according to the increment of aboveground vegetation value (Ivc). Although the aboveground vegetation value (Ivc) showed a tendency to increase logarithmically during the secondary succession after forest fire, the estimated fine roots of the topsoil was depicted the parabola form showing the gradual increment until the first 15 years and slight decrease thereafter. Decrease of FRT in the later successional stage showing the high vegetation value may be caused by increment of the woody species contribution to the vegetation value (Ivc). Our results represented that the aboveground vegetation value (Ivc) can be used to the estimation of the fine roots of the topsoil in burned forest areas.

• The Journal of Engineering Geology
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• v.25 no.4
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• pp.533-545
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• 2015

Spatial and seasonal variations in hydrogeochemical characteristics and the factors affecting the deterioration in quality of shallow portable groundwater in an agricultural area are examined. The aquifer consists of (from the surface to depth) agricultural soil, weathered soil, weathered rock, and bedrock. The geochemical signatures of the shallow groundwater are mostly affected by the NO₃⁻ and Cl⁻ contaminants that show a gradual downward increase in concentration from the upper area, due to the irregular distribution of contamination sources. The concentrations of the major cations do not varied with the elapsed time and the NO₃⁻ and Cl⁻ ions, when compared with concentrations in background groundwater, increase gradually with the distance from the upper area. This result suggests that the water quality in shallow groundwater deteriorates due to contaminant sources at the surface. The contaminations of the major contaminants in groundwater show a positive linear relationship with electrical conductivity, indicating the deterioration in water quality is related to the effects of the contaminants. The relationships between contaminant concentrations, as inferred from the ternary plots, show the contaminant concentrations in organic fertilizer are positively related to concentrations of NO₃⁻, Cl⁻, and SO₄²⁻ ions in the shallow portable groundwaters, which means the fertilizer is the main contaminant source. The results also show that the deterioration in shallow groundwater quality is caused mainly by NO₃⁻ and Cl⁻ derived from organic fertilizer with additional SO₄²⁻ contaminant from livestock wastes. Even though the concentrations of the contaminants within the shallow groundwaters and the contaminant sources are largely variable, it is useful to consider the ratio of contaminant concentrations and the relationship between contaminants in groundwater samples and in the contaminant source when analyzing deterioration in water quality.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.2
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• pp.75-85
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• 2010

The purpose of this study is to attempt new analysis on Soswaewon Garden(瀟灑園) where is Korea's traditional garden, focusing on which the tendency of its change is a relational-formation tool similar to the Eastern Mode of Thought, with paying attention to conversion as the new view of world. Accordingly, the aim is to reanalyze by connecting with Soswaewon Garden based on the theory of complexity, which tries to look at the whole through relationship rather than characteristics in individual components. Given summarizing findings, those are as follows. First, it was found that complexity shown in space and open system of physical dimension was characterized by 'event(situation)', 'non-determination' and 'homogeneous relationships between part and whole', and a variety of techniques introduced the nature positively. In particular, it was found that there were many cases of topographic usage, since the Soswaewon Garden selected its construction site proactively and was a product from architectural works in compliance with a given flow of natural topography. This has a nature of open text in the situation of emergent behaviors. Second, it was found that complexity shown in experiences and open system on the invisible dimension was characterized primarily by 'event(situation)' and 'relationships of interactive response between actors and environment', and various techniques appeared as a space for interactive combination of nature and daily experiences. This is typical of bilateral harmony based on interactions between subject and object, and between mankind and nature, and becomes also a space to accommodate temporary emergent behaviors in our life. Third, the compositional elements are reconstituted as space of organic property with dismantling steady relations. Especially, 'Soswaewon Garden's 48 poems(瀟灑園四十八詠)' will be the origin of the emotionally spatial experience to the current performers. Ultimately, the performer in the space of Soswaewon Garden simultaneously becomes a creator of space, and will generate new space with intertextuality with environment. Therefore, Soswaewon Garden becomes a place of binding me and the other together while maintaining mutual relationship based on organic thinking between a human being and nature and between the whole and a part.

• Journal of Astronomy and Space Sciences
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• v.36 no.1
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• pp.21-33
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• 2019

This paper focuses on the interpretation of radiation fluxes from active galactic nuclei. The advantage of positron annihilation spectroscopy over other methods of spectral diagnostics of active galactic nuclei (therefore AGN) is demonstrated. A relationship between regular and random components in both bolometric and spectral composition of fluxes of quanta and particles generated in AGN is found. We consider their diffuse component separately and also detect radiative feedback after the passage of high-velocity cosmic rays and hard quanta through gas-and-dust aggregates surrounding massive black holes in AGN. The motion of relativistic positrons and electrons in such complex systems produces secondary radiation throughout the whole investigated region of active galactic nuclei in form of cylinder with radius R= 400-1000 pc and height H=200-400 pc, thus causing their visible luminescence across all spectral bands. We obtain radiation and electron energy distribution functions depending on the spatial distribution of the investigated bulk of matter in AGN. Radiation luminescence of the non-central part of AGN is a response to the effects of particles and quanta falling from its center created by atoms, molecules and dust of its diffuse component. The cross-sections for the single-photon annihilation of positrons of different energies with atoms in these active galactic nuclei are determined. For the first time we use the data on the change in chemical composition due to spallation reactions induced by high-energy particles. We establish or define more accurately how the energies of the incident positron, emitted ${\gamma}-quantum$ and recoiling nucleus correlate with the atomic number and weight of the target nucleus. For light elements, we provide detailed tables of all indicated parameters. A new criterion is proposed, based on the use of the ratio of the fluxes of ${\gamma}-quanta$ formed in one- and two-photon annihilation of positrons in a diffuse medium. It is concluded that, as is the case in young supernova remnants, the two-photon annihilation tends to occur in solid-state grains as a result of active loss of kinetic energy of positrons due to ionisation down to thermal energy of free electrons. The single-photon annihilation of positrons manifests itself in the gas component of active galactic nuclei. Such annihilation occurs as interaction between positrons and K-shell electrons; hence, it is suitable for identification of the chemical state of substances comprising the gas component of the investigated media. Specific physical media producing high fluxes of positrons are discussed; it allowed a significant reduction in the number of reaction channels generating positrons. We estimate the brightness distribution in the ${\gamma}-ray$ spectra of the gas-and-dust media through which positron fluxes travel with the energy range similar to that recorded by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) research module. Based on the results of our calculations, we analyse the reasons for such a high power of positrons to penetrate through gas-and-dust aggregates. The energy loss of positrons by ionisation is compared to the production of secondary positrons by high-energy cosmic rays in order to determine the depth of their penetration into gas-and-dust aggregations clustered in active galactic nuclei. The relationship between the energy of ${\gamma}-quanta$ emitted upon the single-photon annihilation and the energy of incident electrons is established. The obtained cross sections for positron interactions with bound electrons of the diffuse component of the non-central, peripheral AGN regions allowed us to obtain new spectroscopic characteristics of the atoms involved in single-photon annihilation.

• Korean Journal of Remote Sensing
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• v.33 no.6_1
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• pp.931-946
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• 2017

The purpose of this study is to observe and analyze soil moisture conditions with high resolution and to evaluate its application feasibility to agriculture. For this purpose, we used three Landsat-8 OLI (Operational Land Imager)/TIRS (Thermal Infrared Sensor) optical and thermal infrared satellite images taken from May to June 2015, 2016, and 2017, including the rural areas of Jeollabuk-do, where 46% of agricultural areas are located. The soil moisture conditions at each date in the study area can be effectively obtained through the SPI (Standardized Precipitation Index)3 drought index, and each image has near normal, moderately wet, and moderately dry soil moisture conditions. The temperature vegetation dryness index (TVDI) was calculated to observe the soil moisture status from the Landsat-8 OLI/TIRS images with different soil moisture conditions and to compare and analyze the soil moisture conditions obtained from the SPI3 drought index. TVDI is estimated from the relationship between LST (Land Surface Temperature) and NDVI (Normalized Difference Vegetation Index) calculated from Landsat-8 OLI/TIRS satellite images. The maximum/minimum values of LST according to NDVI are extracted from the distribution of pixels in the feature space of LST-NDVI, and the Dry/Wet edges of LST according to NDVI can be determined by linear regression analysis. The TVDI value is obtained by calculating the ratio of the LST value between the two edges. We classified the relative soil moisture conditions from the TVDI values into five stages: very wet, wet, normal, dry, and very dry and compared to the soil moisture conditions obtained from SPI3. Due to the rice-planing season from May to June, 62% of the whole images were classified as wet and very wet due to paddy field areas which are the largest proportions in the image. Also, the pixels classified as normal were analyzed because of the influence of the field area in the image. The TVDI classification results for the whole image roughly corresponded to the SPI3 soil moisture condition, but they did not correspond to the subdivision results which are very dry, wet, and very wet. In addition, after extracting and classifying agricultural areas of paddy field and field, the paddy field area did not correspond to the SPI3 drought index in the very dry, normal and very wet classification results, and the field area did not correspond to the SPI3 drought index in the normal classification. This is considered to be a problem in Dry/Wet edge estimation due to outlier such as extremely dry bare soil and very wet paddy field area, water, cloud and mountain topography effects (shadow). However, in the agricultural area, especially the field area, in May to June, it was possible to effectively observe the soil moisture conditions as a subdivision. It is expected that the application of this method will be possible by observing the temporal and spatial changes of the soil moisture status in the agricultural area using the optical satellite with high spatial resolution and forecasting the agricultural production.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.40 no.3
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• pp.20-35
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• 2022

This study was conducted on the locational results of the 'Yusanggoksu(流觴曲水)' petroglyphs located in Hwanggak-dong(黃閣洞), Shinsong-ri, Geumma-myeon, Iksan-si through literature study, analysis of old maps and aerial photos, field observations, drone photography, elevation surveys, and interviews with residents. It was attempted for the purpose of illuminating and preserving the relics of the domestic Yusanggoksu garden by clarifying the spatiality of this place by tracing the spatiality and examining the possibility of enjoying the Yusanggoksu water system in this place. The conclusion of this study is as follows. The area around Hwanggak-dong, where the Yusanggoksu remains, has been selected as the most beautiful scenic spot in Iksan in various documents. The origin of 'Hwanggak' is considered to be closely related to the nickname of Uijeongbu(議政府). In other words, he paid attention to the relationship with Yanggok, So Se-yang(蘇世讓), who served as Chan-seong Jwa(左贊成). In particular, he paid attention to the relationship with his birthplace, Taeheojeong, a separate book, and Toehyudang, a retreat hall), tombs, and posthumous Confucian academies were distributed in the vicinity. Haseo-dae(荷鋤臺), a wide rock on which a hoe is hung on a rock after field work, seems to express a leisurely rural life and a simple and hermit life, based on the examples of Chinese and Korean poetry. The dark blood on the upper part of the Seobwi Rock with the inscription 'Yusanggoksu', which is the core of this site, is identified as a chailgong(遮日孔) to support the water system, and Ilgan-pavilion and Mojeong(茅亭) nearby are to support the yusanggoksu. It seems to have performed a spatial function for The inscription 'Hwanggak-dong' engraved on the front of Deungzanbawi is the gateway to Hwanggakdongcheon(黃閣洞天) and identified the idealized world existing in the village. Judging from the documentary records of the Iksan-gun 『Chongswaelog(叢瑣錄)』, the rock letters 'Hwanggak-dong' and 'Haseodae' were engraved on March 29, 1901, the 5th year of Gwangmu, the 5th year of the Korean Empire, by Iksan-gun Governor Oh Haeng-mook(吳宖默) and his acquaintance Seokseong Kim In-gil(金寅吉) Confirmed. Also, considering the tense of Lee Bong-gu's 「Hwanggakdongun(黃閣洞韻)」 and So Jin-deok, a descendant of Yanggok, 「Hwanggakdongsihoe(黃閣洞詩會)」, it is presumed that it was related to Goksuyeon(曲水宴) in Hwanggak-dong. It can be inferred that the current affairs meetings were held at least until the early days of Japanese colonial rule. Meanwhile, the maximum width of the current curved waterway was calculated as 11.3m and the transverse slope was 15.0%. If so, it is estimated that the width and extension distance of the curved waterway would have been much longer. Judging from the use of mochun(暮春), drinking and poetry, the tense 'Hwanggakdongsihoe' related to the Yusanggoksu relics in Hwanggak-dong, and the existence of a pavilion presumed to be Yusangjeong(流觴亭) called Ilgan-pavilion in the nearby Yusanggoksu site It is confirmed that it was a space where Yusanggoksuyeon(流觴曲水宴) spread at least until the end of the Joseon Dynasty. Unfortunately, it remains a limitation of the study that it cannot be confirmed due to lack of data on the rock characters of 'Yusanggoksu' and those who enjoyed it before the end of the Joseon Dynasty. This is an area that needs to be elucidated through continuous efforts to find data on this issue in the future.

• Korean Journal of Cognitive Science
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• v.27 no.2
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• pp.159-219
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• 2016

Mathematical ability is important for academic achievement and technological renovations in the STEM disciplines. This study concentrated on the relationship between neural basis of mathematical cognition and its mechanisms. These cognitive functions include domain specific abilities such as numerical skills and visuospatial abilities, as well as domain general abilities which include language, long term memory, and working memory capacity. Individuals can perform higher cognitive functions such as abstract thinking and reasoning based on these basic cognitive functions. The next topic covered in this study is about individual differences in mathematical abilities. Neural efficiency theory was incorporated in this study to view mathematical talent. According to the theory, a person with mathematical talent uses his or her brain more efficiently than the effortful endeavour of the average human being. Mathematically gifted students show different brain activities when compared to average students. Interhemispheric and intrahemispheric connectivities are enhanced in those students, particularly in the right brain along fronto-parietal longitudinal fasciculus. The third topic deals with growth and development in mathematical capacity. As individuals mature, practice mathematical skills, and gain knowledge, such changes are reflected in cortical activation, which include changes in the activation level, redistribution, and reorganization in the supporting cortex. Among these, reorganization can be related to neural plasticity. Neural plasticity was observed in professional mathematicians and children with mathematical learning disabilities. Last topic is about mathematical creativity viewed from Neural Darwinism. When the brain is faced with a novel problem, it needs to collect all of the necessary concepts(knowledge) from long term memory, make multitudes of connections, and test which ones have the highest probability in helping solve the unusual problem. Having followed the above brain modifying steps, once the brain finally finds the correct response to the novel problem, the final response comes as a form of inspiration. For a novice, the first step of acquisition of knowledge structure is the most important. However, as expertise increases, the latter two stages of making connections and selection become more important.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.343-352
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• 1998

The relationship between summer hypoxia in bottom water layer and benthic community structure was discussed at forty sampling stations in semi-enclosed Youngsan River estuarine bay, Korea. The oxygen deficient layer less than $2.0 mg/\ell$ was widely developed in the inner estuarine stations in summer due to the summer stratification. A total of 141 species was occurred, with a mean density of $1,923 ind./m^2$ and biomass of $79.44\;g/m^2$ in summer season. The species number was significantly increased with the increment of the bottom dissolved oxygen, whereas density and biomass were partially correlated within the low oxygen level of $2.0\;mg/\ell$. These results imply that benthic community structures are affected by bottom oxygen depletion in summer. Cluster analysis showed that the benthic community could be classified into three station groups. These station groups from the species composition coincided with the groups based on the environmental factors. This fact suggests that the overall spatial distribution of macrozoobenthos in Youngsan River estuarine bay in summer should be controlled by the summer hypoxia and clay content of the area. Group-I was located the innermost estunrine bay from Mokpo Harbour to near the dike, where summer hypoxia was developed and one bivalve Theora fragilis, two polychaetes, Tharyx sp. and Lumbrineris longifolia were dominated. Group-II, the central transitory area of the estuarine bay between two another stational groups, where two bivalves Theora fragilis, Raetellops pulchella and a polychaete Tharyx sp. predominated with relatively low density compared to that of Group-I. Group-III, the mouth part of the estunrine bay exposed to the open sea, where a polychaetes Poecilochaetus johnsoni and a bivalve Yoldia Johanni predominated.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.3
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• pp.1-12
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• 2014

Urban Green space takes charge of the important role for the physical activity and promotion of health to the residents. Therefore, this study is trying to examine the relationship between the various characteristics of green space and green space usage for physical activity and health promotion. A questionnaire survey was conducted to obtain the information about patterns of green space usage and perceived neighborhood environments for the residents living in Changwon-si, Gyeongsangnam-do(n=541). Geographic Information System(GIS) was used to construct spatial data about green space accessibility and physical neighborhood environments. A Multiple Linear Regression model was used to examine the association between the characteristics of green space and physical activity, perceived health status and BMI(Body Mass Index). The study results revealed that the residents' physical activities are positively and directly influenced by the number of available public parks and green spaces in the vicinity(${\leq}200m$). The frequency at which residents witness others exercising nearby or the perceived abundance of low-cost gym facilities also factor as positive influences. The closer to the park, the higher the number of parks and area of green spaces, the more comfortable the walk thereto and the denser the neighboring residential area distribution, the perceived health level was found to be the more positively influenced. Further, it was verified that BMI is correlated with the number of public parks and green spaces within 400 m of the resident's home as well as the safety of walkways, the density of neighboring residential areas, the ratio of road, and the density of crosswalk. The significant multiple regression models between the characteristics of green spaces and physical activities and perceived health level were extracted within the significance level of 10%. This study will contribute to provide better understanding the ways in which green space and neighborhood characteristics are associated with physical activity and health. The result of this research will be available in the landscape architecture plan aimed at improving the use of green space for physical activity and reducing obesity.

• Journal of the Korean Geographical Society
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• v.42 no.4
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• pp.469-487
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• 2007

Grain-Size Trend Analysis is the methodology to identify net sediment transport pathways, based on the assumption that the movement of sediment from the source to deposit leaves the identifiable spatial pattern of mean, sorting, and skewness of grain size. It can easily be implemented with low cost, so it has great potentials to contribute to geomorphological research, whereas it can also be used inadequately without recognition of its limitations. This research aims to compare three established methods of grain-size trend analysis to search for the adequate way of application, and also suggest the research tasks needed in improving this methodology 1D pathway method can corporate the field experience into analyzing the pathway, provide the useful information of depositional environments through X-distribution, and identify the long-term trend effectively. However, it has disadvantage of the dependence on subjective interpretation, and a relatively coarse temporal scale. Gao-Collins's 2D transport vector method has the objective procedure, has the capability to visualize the transport pattern in 2D format, and to identify the pattern at a finer temporal scale, whereas characteristic distance and semiquantitative filtering are controversial. Le Roux's alternative 2D transport vector method has two improvement of Gao-Collins's in that it expands the empirical rules, considers the gradient of each parameters as well as the order, and has the ability to identify the pattern at a finer temporal scale, while the basic concepts are arbitrary and complicated. The application of grain sire trend analysis requires the selection of adequate method and the design of proper sampling scheme, based on the field knowledge of researcher, the temporal scale of sediment transport pattern targeted, and information needed. Besides, the relationship between the depth of sample and representative temporal scale should be systematically investigated in improving this methodology.