• Journal of The Korean Society of Agricultural Engineers
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• v.66 no.2
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• pp.25-34
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• 2024

The long-term monitoring of the Soyang Lake's water quality, covering 25% of the North Han River watershed, is crucial for effective management of both lake water quality and pollution sources in the broader region. This study utilized continuous monitoring data from the front of the Soyang Dam spanning 2003 to 2022, aiming to analyze trends and provide foundational insights for water quality management. Results revealed a slightly poor grade (IV) for total nitrogen (T-N) in both surface and mid-depth layers, indicating a need for concentrated T-N management. Trend analyses using the Mann-Kendall test and Sen's Slope depicted a decreasing trend in total phosphorus (T-P) for both layers, attributed to non-point source pollution reduction projects initiated after the Soyang Lake's designation as a pollution control area in 2007. The LOWESS analysis showed a T-P increase until 2006, followed by a decrease, influenced by the impact of Typhoon Ewiniar in that year. This 20-year overview establishes a comprehensive understanding of the Soyang Lake's water quality and trends, allowing for a seasonal and periodical analysis of water quality changes. The findings underscore the importance of continued monitoring and management strategies to address evolving water quality issues in the Soyang Lake over time.

• The Journal of the Convergence on Culture Technology
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• v.11 no.1
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• pp.389-399
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• 2025

This study explores twigak(fried seaweed crisps) made from kelp (Dasima) from the Goryeo Dynasty to the modern era. Kelp, a major local product of the Hamgyeong Province, was closely linked to the region's dietary culture. Over time, kelp evolved into various dishes, including twigak, bugak, and maedeup-jaban. The term twigakbegan to be used in the mid-19th century, reflecting the identity of the Korean language. Kelp bugak, made by coating kelp with glutinous rice paste and frying it, became a visually appealing winter dish, while maedeup-jabandeveloped into a year-round delicacy. Even today, kelp-based dishes remain significant in Korean cuisine, balancing health and flavor. This underscores the sustainable nature of traditional Korean food. In conclusion, the study reexamines the value and significance of kelp in Korean cuisine and highlights the need for future research into the nutritional value and culinary diversity of kelp and other seaweeds. Such research is expected to contribute to a deeper understanding of the evolution and innovation of kelp-based dishes.

• Korean Journal of Environment and Ecology
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• v.11 no.3
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• pp.334-351
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• 1997

To study restoration model of evergreen broad-leaved forests in warm temperate region, vegetation structure was studied at Wando(Island) as a case study. Quercus acuta was a dominant species at evergreen broad-leaved forests in Wando(Island). Majority of evergreen broad-leaved forests was a thirty years old coppice forest. Reforested vegetation and deciduous broad-leaved forests was developed at a mid-slope districts and a piedmont. Deciduous broad-leaved forestsconsisted of Quercus serrata, Carpinus tschonoskii, Carpinus coreana, etc., was developed at a ridge and higher districts. Evergreen broad-leaved woody plants were growing at a forest floor of deciduous broad-leaved forests. The species over sixty percent of constanty ratio in forty seven plots were Ligustrum japonicum, Trachelospermum asiaticum var. intermedium, Quercus acuta and Eury japonica. The vascular plants in the Wando(Island) was summarized as 488 taxa which composed as 101 families, 321 genus, 426 species, 56 varieties, 5 forms and 1 hyvrid. Evergreen broad-leaved woody stecies was 32 taxa which composed as 23 genus, 30 species and 2 varieties. The species such as Liliope platyphylla of Liliaceae and Pueraria thunbergii of Leguminosae, etc. was recorded as the highest values for their widely distribution in the areas. On the contrary, and forty taxa of plants such as Viburnum erosum of Caprifoliaceae, Traceholospermum asiaticum var. intermedium was recorded as over 50% of constancy ratio. Two hundred and nine taxa of plants such as Juglans manshurica of Juglandaceae, Cornus walteri of Cornaceae and Rodotypos scandens of Rosaceae, etc. was showed the specific trends due to long-term artificial disturbance. The forest of Pinus thunbergii showde the highest species diversities(155 species per 600m$^{2}$), while the Cinnamomum japonicum-Tracheolospermum asiaticum var. intermedium community showed the lowest species diversities(23 species per 600m$^{2}$).

• Economic and Environmental Geology
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• v.51 no.5
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• pp.463-471
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• 2018

In this paper, we review previous studies on the relative sea-level changes in the Yellow Sea during the Holocene to comprehensive understand the various research results. Currently, it is reported two theories : 1) the Holocene sea-level has never been higher than the present-day level; and 2) sea-level have reached highstand during mid-Holocene, followed by slow lowering to that of the present. The first theory yields a curve that is similar to a climate-change-related eustatic sea-level curve. However, in reality, most of the relative sea-level fluctuation resulted from land uplift or subsidence. The second theory yields a curve that is fairly coincident with a relative sea-level curve indicative of continental margins being located away from the ice sheets(i.e., far-field), and is considered as an effect of GIA(Glacio Isostatic Adjustment) and gravitational attraction. Based on detailed review of previous researches, we realized that they sourced the same papers, but obtained different results because they selectively chose and added the data. The data used to derive the second theory pertain to the northern Gunsan region, which is located within the western area of the Chugaryeong fault. Thus, we believe that the sea-level curve for the second theory is only representative of the area north of Gunsan, which is subject to GIA and tectonic deformation. Although the relative sea-level curve for the west coastal area is comparable to that for the far-field continental margin region, it is necessary to evaluate local tectonic activities as suggested by active seismicity in the west coastal area and the more than 400 faults currently existing in on the Korean Peninsula.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.2
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• pp.87-92
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• 2002

Soil erosion is detrimental to sustain soil productivity in north Korea, since agriculture of this country depends largely upon the slope land in mountainous area. Taking any measure for protection from erosion should be based on prediction of soil loss. Estimation of rainfall factor, R, in north Korea for the Universal Soil Loss Equation was attempted. The monthly precipitation data of the twenty six locations provided by the Korean Meteorological Adminstration were used. From the relationship between II_30 and the July-August precipitation concentration percents, the regional adjustment factor was obtained. The rainfall factor was calculated with the monthly precipitation data and the regional adjustment factor. The annual precipitation in north Korea ranged from 606 to 1,520mm, and the July-August precipitation concentration percents were 34.4 to 53.8. The regional adjustment factor ranged from 0.53 to 1.33 showing lower value in the highland and east coastal region than in the mid mountainous inland and west region. The R-factor value estimated from the monthly precipitation and the regional adjustment factor ranged from 107 to 483, which was lower than average value in south Korea.

• Land and Housing Review
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• v.6 no.2
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• pp.101-106
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• 2015

In order to minimize regional disparities between the North and the South, it is very important to reduce shortages of food and energy in North Korea in the short and mid-term. In the long term, it is important to reduce not only regional disparities between two Koreas but also regional disparities in North Korea. It is important to consider national policies of the North, the South and other countries in Northeast Asia in the process of building regional development policies for North Korea because the future of regional development in North Korea depends on policies of stakeholder in Northeast Asia. This study suggest some policy directions for regional development in North Korea. At first, building new industries, such as hi-tech industries and MICE, is important for regional development potentials in North Korea. Also, we should take some special development strategies according to regional potentials in North Korea. For example, Nampo region should be specialized through hi-tech industries. Wonsan region should be specialized through MICE. Finally, this study suggests some policy issues to the South Korean government. Financial support from South Korean government about inter-Korean economic cooperation should have priorities on the regions where have potentials of hi-tech industries and MICE. Also, we should implement inter-Korean economic cooperation policies under consideration about spatial aspects.

• The KIPS Transactions:PartB
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• v.17B no.6
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• pp.421-428
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• 2010

It takes a long time for the users to view a whole image from the image server under the low-bandwidth internet environments or in case of a big sized image. In this case, as there needs a technique that preferentially transfers a part of image, JPEG2000 offers a ROI(Region-of-Interest) coding. In ROI coding, the users see the thumbnail of image from the server and specifies some regions that they want to see first. And then if an information about the regions are informed to the server, the server preferentially transfers the regions of the image. The existing methods requested a huge time to compute the mask information, but this thesis approximately computes the regions and reduces the creating time of the ROI masks. If each code block is a mixed block which ROI and background are mixed, the proper boundary points should be acquired. Searching the edges of the block, getting the two points on the edge, to get the boundary point inside the code block, the method searches a mid point between the two edge points. The proposed method doesn't have a big difference compared to the existing methods in quality, but the processing time is more speedy than the ones.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.2
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• pp.205-211
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• 2016

Based on the Expendable Bathythermograph (XBT) observation and serial oceanographic observation of National Institute of Fisheries Science (NIFS) during July 2013 to July 2015, we examined the temperature variation in the Ulleung Warm Eddy (UWE) in the East Sea. The UWE was always shown during the observation periods even though it was not the whole shape. The coefficient of variation (CV) was largest in the depth of 250 m at the side of the east coast of Korean Peninsula with $3{\sim}4^{\circ}C$ in temperature. CV of the horizontal distribution at 250 m depth was also largest in the region biased along the east coast of Korea. The warm eddy moved not only to the east-west direction but also to the north-south direction in the viewpoint of horizontal distributions of temperature. This region between the Korean Peninsula and Ulleung island also is the passage of the East Korean Warm Current. This means that interaction between the East Korean Warm Current and periphery of warm eddy makes large in the variation of movement along the east coast of Korean Peninsula. The largest variation of temperature at 250 m depth seemed to be significantly correlated with the East Sea Intermediate Water (ESIW) underlying Ulleung Warm Eddy. It is suggested that the interaction between the ESIW and UWE is active in the mid-depth along the periphery of UWE.

• Research in Plant Disease
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• v.22 no.4
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• pp.269-275
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• 2016

Black shoot blight disease caused by Erwinia pyrifoliae have damaged economic loss to apple and pear growers until now since it was firstly reported in 1995 in Korea. This study was performed to reduce economic loss by mandatory eradication of all infected trees in case of more 10% disease incidence per orchard as official control. It also aims to set up effective management protocol for this disease by examining how far bacterial pathogen is present from the border of symptomatic and asymptomatic regions in infected apple twigs. Colony-PCR using isolated bacterial cells instead of genomic DNA was used to identify bacterial pathogen, EpSPF/EpSPR primer designed in enterobacterial repetitive intergenic consensus (ERIC) region was selected as specific for E. pyrifoliae. As results of monitoring of this disease during April to October in 2014-2015 by colony-PCR, occurrence of this disease was frequent from mid-May to early-July, when daily average temperature was around $25^{\circ}C$. Moreover, bacterial cells were continuously detected only in symptomatic regions and also asymptomatic regions of less than 20 cm from symptomatic regions. Therefore, we concluded that pruning of infected twigs at the region of more than 20 cm from symptomatic regions might be effective to manage black shoot blight disease in apple trees.

• Korean Journal of Ecology and Environment
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• v.43 no.1
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• pp.69-81
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• 2010

This study was conducted at 25 sites of 6 mainstreams and 19 tributaries sites within Heuck Stream watershed during May~October 2003 for the survey of fish distributions, compositions, and community characteristics. The survey showed that total fish was identified as 9 family and 26 species in all sites, and Cyprinidae dominated the community as 15 species. The dominant species of >20% of the total were Zacco temminckii (29%), Zacco platypus (22%), and Rhynchocypris oxycephalus (21%) in the watershed. Community analysis, based on the stream spatial gradients, indicated composition differences along the main axis of the stream from the headwater to the downstream; R. oxycephalus predominated in the most headwater zone and Z. temminckii dominated in the lower headwater zone, whereas Z. temminckii -Z. platypus dominated in the mid-to-downstream, and Z. platypus dominated the community in the most downstream zone. Total endemic species was 7 family and 15 species, which is made of 50% in the fish community, so that the high proportion of endemic species indicated a healthy region in terms of fish community, compared to average 23% in Korean peninsula in general. The total number and species of fish increased as the stream order (stream size) increased, indicating that impacts on chemical pollution or habitat disturbance were not so large to the fish community in this watershed. Trophic and tolerance guilds analysis showed that relative proportions of sensitive and insectivore species were >50% in the watershed and decreased as the stream order increased, whereas relative proportions of tolerant and omnivore species showed an opposite results. These outcomes suggest that the natural condition of watershed is preserved relatively and the region should be protected from the chemical and habitat disturbace by agricultural activity and urban developments.