• The Korean Journal of Quaternary Research
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• v.24 no.2
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• pp.23-34
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• 2010

The purpose of this study is to clarify the characteristics of geomorphic surfaces and investigate their geomorphological development at Sinsong-ri archaeological sites by the classification of geomorphic surfaces. The sedimentary facies of trench 1, 2 and 3 were identified and pollen analysis was performed at site 3. The geomorphic surfaces are classified by hillslope, valley plain, alluvial fan and river terrace. Most of the study area is located on low hillsides and valley plains are connected with tidal flats extended from small river valley. Also, alluvial fans are distributed over the piedmont and narrow, long river terraces are developed downstream along the Sojeong-stream flowing between valley plain and hillsides. River valleys were deeply eroded during the Last Glacial Maximum (LGM) periods, responded to the lowest sea level among the hillslopes and valley plains are formed during the Holocene. The sedimentary facies are identified composed of basal gravel layers with coarse gravels and sands, relatively thick culture layer of the Bronze Age and thin layer during the early Iron Age in upper part study area. Thus, land uses during the Bronze Age people was performed more intensively comparing to the early Iron Age by deforestation for habitation.

• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.51-67
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• 1996

There are three main rice-growing regions in the United States: the prairie region along the Mississippi River Valley in eastern Arkansas; the Gulf Coast prairie region in southwestern Louisiana and southeastern Texas; and the Central Valley of California. The Central Valley of California is producing about 23% of the US rice(Fig. 1). In California. most of the crop has been produced in the Colusa, Sutter, Butte, Glenn Counties of the Sacramento Valley since 1912, when rice was commercially grown for the first time in the state(Fig. 2). Roughly speaking, the average annual area sown to rice in California is about 300,000 acres to 400,000 acres during the last forty years(Fig. 3). California rice is grown under a Mediterranean climate characterized by warm, dry, clear days, and a long growing season favorable to high photosynthetic rates and high rice yields. The average rice yield per acre is probably higher in California than in any other rice-growing regions of the world(Fig. 4). A dependable supply of irrigation water must be available for a successful rice culture. Most of the irrigation water for California rice comes from the winter rain and snow-fed reservoir of the Sierra Nevada mountain ranges. Less than 10 percent of rice irrigation water is pumped from wells in areas where surface water is not sufficient. It is also essential to have good surface drainage if maximum yields are to be produced. Rice production in California is highly mechanized, requiring only about four hours of labor per acre. Mechanization of rice culture in California includes laser-leveler technology, large tractors, self-propelled combines for harvesting, and aircraft for seeding, pest control, and some fertilization. The principal varieties grown in California are medium-grain japonica types with origins from the cooler rice climates of the northern latitudes (Table 1). Long-grain varieties grown in the American South are not well adapted to California's cooler environment. Nearly all the rice grown recently in California are improved into semidwarf varieties. Choice of variety depends on environment, planting date, quality desired, marketing, and harvesting scheduling. The Rice Experiment Station at Biggs is owned, financed, and administered by the rice industry. The station was established in 1912, as a direct result of the foresight and effort of Charles Edward Chambliss of the United States Department of Agriculture. Now, The station's major effort is the development of improved rice varieties for California.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.261-266
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• 2015

We have analyzed the external morphology and the environment of the foraging site of Vespertilio sinensis. The external morphology was analyzed by twelve parameters and the environment characteristics of the foraging site was analyzed using GIS 10.1 program. The wing membrane was inserted into the ankle of the hind foot and the wing ratio was 1.42, the middle type between broad-short wing type and long-narrow wing type. The fur color was blackish brown but the guard hair color was whitish. The shape of the ear was a rounded triangle and tragus was a fan shape. This study showed that V. sinensis preferred the deciduous forest of the upper forest zone, where human interference was less. We believed that abundance of insects, depending on water system, was closely related to the use of the foraging site. This result showed that the environment characteristics was very similar to the nature preservation zone including Baekyang valley and Keumsun valley in Naejangsan National Park.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.1
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• pp.1-14
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• 2021

The study has been carried out with an objective to prepare Siberian roe deer habitat potential maps in South Korea based on three geographic information system-based models including frequency ratio (FR) as a bivariate statistical approach as well as convolutional neural network (CNN) and long short-term memory (LSTM) as machine learning algorithms. According to field observations, 741 locations were reported as roe deer's habitat preferences. The dataset were divided with a proportion of 70:30 for constructing models and validation purposes. Through FR model, a total of 10 influential factors were opted for the modelling process, namely altitude, valley depth, slope height, topographic position index (TPI), topographic wetness index (TWI), normalized difference water index, drainage density, road density, radar intensity, and morphological feature. The results of variable importance analysis determined that TPI, TWI, altitude and valley depth have higher impact on predicting. Furthermore, the area under the receiver operating characteristic (ROC) curve was applied to assess the prediction accuracies of three models. The results showed that all the models almost have similar performances, but LSTM model had relatively higher prediction ability in comparison to FR and CNN models with the accuracy of 76% and 73% during the training and validation process. The obtained map of LSTM model was categorized into five classes of potentiality including very low, low, moderate, high and very high with proportions of 19.70%, 19.81%, 19.31%, 19.86%, and 21.31%, respectively. The resultant potential maps may be valuable to monitor and preserve the Siberian roe deer habitats.

• Journal of the Korean Ceramic Society
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• v.47 no.1
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• pp.1-7
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• 2010

Solid oxide fuel cells (SOFCs) have been under development for a variety of power generation applications. Power system sizes considered range from small watt-size units (e.g., 50-W portable devices) to very large multi-megawatt systems (e.g., 500-MW base load power plants). Because of the reversibility of its operation, the SOFC has also been developed to operate under reverse or electrolysis mode for hydrogen production from steam (In this case, the cell is referred to as solid oxide electrolysis cell or SOEC.). Potential applications for the SOEC include on-site and large-scale hydrogen production. One critical requirement for practical uses of these systems is long-term performance stability under specified operating conditions. Intrinsic material properties and operating environments can have significant effects on cell performance stability, thus performance degradation rate. This paper discusses potential applications of the SOFC/SOEC, technological status and current research and development (R&D) direction, and certain aspects of long-term performance degradation in the operation of SOFCs/SOECs for power generation/hydrogen production.

• Korean Journal of Environment and Ecology
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• v.28 no.1
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• pp.45-54
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• 2014

This study was carried out to investigate the ecological succession sere and conservative value, and to provide the basic data in Woonsooam Valley, in Jogyesan (Mt.) (altitude 884m), Suncheon City, Korea by analysing the structure of the plant community. Fifteen plots (size is $20m{\times}20m$) were set up at an altitude of range from 255m to 495m. As a result of analysis of DCA which is one of the ordination technique, the plant communities were divided into five groups which are community I (Pinus densiflora community), community II (Quercus variabilis-Quercus serrata community), community III (Q. serrata-Q. variabilis community), and community IV (Carpinus tschonoskii-Q. serrata community) and community v(Deciduous broad-leaved forest community). We found out that the vegetation of the study site located in the South Temperate Climate Zone. The study site is found out that Q. serrata community 34.4%, part of slope in valley is the distribution that dominant species is Q. serrata-Q. variabilis community 32.1%. And in valley showed Carpinus tschonoskii community 5.5%. And Sasa borealis was dominant species in the shrub layer. We couldn't supposed that the ecological succession sere of the study site, however we should do a long-term monitoring to investigate the changes of the ecological succession each plant community, According to the index of Shannon's diversity (unit: $400m^2$), community III was ranged from 1.0102 to 1.1013, community V was 0.9945, community II was ranged from 0.7913 to 1.1503, community IV was ranged from 0.8081 to 1.0749 and community I was 0.9273.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.6
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• pp.725-733
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• 2019

Sand dams are structures that can be used as auxiliary water resources in case of drought as sand accumulates due to barriers crossing valley rivers and valley water is stored in the voids, increasing the water level. This structure, which is mainly used in arid regions such as Africa, has not been installed in Korea. In Korea, there are only a few cases where water is taken from debris barriers that prevent debris flow. The purpose of this study is to evaluate the effect of water supply when the sand dam is installed downstream of the existing intake barrier in Seosang-ri valley, Chuncheon. For this purpose, modeling was performed by linking the basin hydrologic model and reservoir routing model. Changes in the water level, storage and discharge in the sand dam reservoir according to the size and intake of the sand dam are presented on a case-by-case basis. As a result of application, it was found that the water supply capacity due to the sand dam installation was improved at 95% reliability. Especially, when the size is L × B × H_o = 25 m × 15 m × 1 m and the pumping rates from intake barrier and sand dam are (Q₁, Q₂) = (30, 20), (35, 15) ㎥/day, the efficiency was the best for water supply of 50 ㎥/day.

• Journal of Nutrition and Health
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• v.43 no.6
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• pp.570-577
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• 2010

Water gets magnetically charged when it is contacted with a magnet. Although magnetic water products have been promoted since the 1930's, they have received very little recognition due to questionable effectiveness. Diethylnitrosamine (DEN) is a widely occurring nitrosamine that is one of the most important environmental carcinogens primarily inducing tumors of liver. In this study, the effect of magnetized water supplementation on lymphocyte DNA damage in ICR mice treated with DEN was evaluated using the Comet assay. Mice were divided into 3 groups: control, DEN, and DEN + magnetized water group. Fifteen mice were maintained in each group for the entire experimental period of 6, 12 and 18 weeks. Five mice in each group were sacrificed at 6, 12, and 18th weeks, followed by the Comet assay using the blood obtained from heart puncture of the mice. The level of lymphocyte DNA damage reflected by tail moment and other DNA damage indices of tail DNA (%) or tail length of the magnetized water group were significantly decreased after the 6th, 12th and 18th weeks of supplementation compared with the positive control, the DEN group. The relative DNA damage of the magnetized water groups compared to the DEN control group after 6th, 12th, and 18th weeks of supplementation were 42.2%, 40.8%, and 32.9% for DNA in tail, 31.2%, 32.6%, and 21.3% for tail length, and 33.8%, 33.8%, and 24.6% for tail moment, respectively. This is the first report demonstrating that magnetized water may be involved in the lowering effect of the DNA damage in DEN-treated ICR mice. This result suggests that the magnetized water might have minimized the DNA damage by improving the antioxidant status of the mice. However, further studies are needed to characterize the condition of the magnetization and examine the long-term effect of the water product.

• Korean Journal of Heritage: History & Science
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• v.48 no.2
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• pp.96-109
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• 2015

The Dresden Elbe Valley of Germany was delisted from the World Heritage List after a long dispute amongst the city of Dresden, UNESCO and the World Heritage Committee upon a plan to build a four-lane bridge within the boundaries of the property. The plan was claimed to threaten the Outstanding Universal Value of the heritage embedded in the view of the river landscape. However looking back on the necessity of the bridge in order to maintain the city dynamics and the needs of the local population, it is possible to diagnose that plans for the bridge had a rather different nature from the usual urban 'development' plans appearing in the vicinity of other World Heritage properties. This article examines the process that led to the delisting of the Elbe Valley from the World Heritage List and assesses the problems arising between the entities which determine the value of the heritage and the entities that implement conservation measures. Recognizing the necessity of involving the local residents, this article stresses the importance of the role of communities in heritage conservation. It is also important to set up dependable directions for establishing conservation policies which takes into account the changing dynamics of the living environment, and sound methods for assessing the impact of future projects on the heritage.

• Journal of Ocean Engineering and Technology
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• v.30 no.6
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• pp.440-450
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• 2016

The capsizing and consequent sinking of a coastal car ferry was recently reported, with numerous human casualties. The primary cause was determined to be a sudden turn with improperly stowed and secured cargo. Part I of this study introduces how long term acceleration components are determined from seakeeping analyses. A carferry with a displacement of 1,633 tonf was selected as the target vessel. Sea data that included the significant wave heights and periods were collected at four observation buoys, some of which were far away from two main voyage routes: Incheon-Jeju and Pusan-Jeju. Frequency response analyses were performed to obtain the linearized radiation force coefficients, hydrostatic stiffnesses, and wave excitation forces. Time response analyses were sequentially performed to produce the motion-induced acceleration processes. The probabilistic distributions of the acceleration components were determined using a peak and valley counting method. Long term extreme acceleration components were proposed as a final result.