• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.273-281
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• 2018

Wet hill seeding (WHS) is one of the more famous labor and money saving methods technology used for rice cultivation. In WHS, rice standing percentage and weedy rice occurrence are the most important factors considered to secure a rice yield. We investigated the optimum seeding date of WHS in the Southern Plain area of South Korea. Weedy rice needed two weeks at $15^{\circ}C$ to show over 80% emergence. Germinated rice seed grown at $20^{\circ}C$ needed over for 10 days to achieve a shoot length over 3 cm. In field cultivation, the mean temperature for ten days after seeding showed a highly positive correlation with rice standing rate, spikelet number per square meter and yield index that favorably compared to machine transplanting. With these data, we suggest that the optimum seeding date of WHS that can secure over 98% of yield index of machine transplanting in Southern part of Korea is May. 21~Jun. 5 in Honam and May. 16~Jun. 5 in Yeongnam area.

• Journal of Korean Society of Disaster and Security
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• v.12 no.2
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• pp.73-82
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• 2019

Recently, as the occurrence frequency of sudden floods due to climate change increased, the flood damage on riverside social infrastructures was extended so that there has been a threat of overflow. Therefore, a rapid prediction of potential flooding in riverside social infrastructure is necessary for administrators. However, most current flood forecasting models including hydraulic model have limitations which are the high accuracy of numerical results but longer simulation time. To alleviate such limitation, data driven models using artificial neural network have been widely used. However, there is a limitation that the existing models can not consider the time-series parameters. In this study the water surface elevation of the Hangang River bridge was predicted using the NARX model considering the time-series parameter. And the results of the ANN and RNN models are compared with the NARX model to determine the suitability of NARX model. Using the 10-year hydrological data from 2009 to 2018, 70% of the hydrological data were used for learning and 15% was used for testing and evaluation respectively. As a result of predicting the water surface elevation after 3 hours from the Hangang River bridge in 2018, the ANN, RNN and NARX models for RMSE were 0.20 m, 0.11 m, and 0.09 m, respectively, and 0.12 m, 0.06 m, and 0.05 m for MAE, and 1.56 m, 0.55 m and 0.10 m for peak errors respectively. By analyzing the error of the prediction results considering the time-series parameters, the NARX model is most suitable for predicting water surface elevation. This is because the NARX model can learn the trend of the time series data and also can derive the accurate prediction value even in the high water surface elevation prediction by using the hyperbolic tangent and Rectified Linear Unit function as an activation function. However, the NARX model has a limit to generate a vanishing gradient as the sequence length becomes longer. In the future, the accuracy of the water surface elevation prediction will be examined by using the LSTM model.

• Korean Journal of Psychosomatic Medicine
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• v.27 no.1
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• pp.60-68
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• 2019

Objectives : The association between thyroid-related hormones and cognitive function has been controversial. The purpose of this study is to compare the levels of thyroid-related hormones in patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI). Furthermore, we investigated the relationship between thyroid-related hormones and cognitive function. Methods : From January 2011 to December 2018, we retrospectively reviewed 105 patients who were diagnosed with AD and MCI by visiting a dementia clinic at Ilsan Paik Hospital. Thyroid-related hormones [triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH)] was measured using chemiluminescent immunoassay. An independent sample t-test was performed to analyze the mean value of thyroid-related hormones in patients of AD and MCI. To investigate whether thyroid-related hormones correlate significantly with Global deterioration scale (GDS), Clinical dementia rating (CDR) and scores of each The Korean version of the consortium to establish a registry for Alzheimer's disease items, we conducted a partial correlation analysis with geriatric depression scale-Korean version (GDS-K) scores as covariates. Results : There was no significant difference in the mean serum T3, T4 and TSH levels between patients of the AD and the MCI, but the Construction Praxis Test (CPT) showed a significant positive correlation with the serum TSH concentration (p-value=0.004). Conclusions : In our study, the positive correlation between serum TSH level and the CPT associated with executive function was found to be helpful in understanding the association between thyroid-related hormones and the pathophysiology of dementia. Prospective studies in regard of the pathophysiology of thyroid-related hormones on cognitive function will be necessary in the future.

• Korean Journal of Heritage: History & Science
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• v.42 no.4
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• pp.152-171
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• 2009

The Dancheong(丹靑) of the main building of Mihwangsa Buddhist Temple(美黃寺) in Haenam(海南) is the leading work of the Jeolla Dancheong style, which was created in the 18th century and has been passed down to the early modern days, and boasts its excellence and originality. On the outside, one can only see the traces of the Dancheong due to the colors that fell off and deteriorated severely. On the inside, however, the general Dancheong pattern is accompanied by the painting of 1,000 Buddhas(千佛圖), which is hardly found in other Buddhist temples, and the Arahan painting, which is truly magnificent in technique and can pass as an independent painting. The Dancheong also has unique methodological characteristics that can't be found in other Dancheong works such as the painting and attaching technique. The Dancheong inside is estimated to have been created in 1754 considering the records of "Dalmasan Mihwangsasa Daebeopdang Jungsusangryangmun(達摩山美黃寺大法堂重修上樑文)", the calligraphical writings of "Mudeungsanindanhwakya(無等山人丹?也)"and "Geonryungshipgu(乾隆十九)" left in the Jungryang, and the style characteristics reflected in the Dancheong patterns and the painting of 1,000 Buddhas. The fact that there are no traces of re-Dancheong also supports the estimation that the Dancheong was created in the absolute age of 1754. The absolute age will be the reference of deciding the chronological years of Dancheong patterns and be helpful in examining the characteristics and changes by the periods. There were certain style characteristics in Dancheong by the periods and regions. The Dancheong of Jeolla region also had its own style, which includes the tendency of finishing with two- or three-fold green belts without giving meokdanggi to the meoricho and the huge jar decoration of huigol. Treating the baetbadak of all materials, whether it's Geumdancheong or morodancheong, with lines of certain thickness and colors is another style of Jeolla Dancheong from the 18th to the 20th century. The Dancheong of the Geukrakbojeon(極樂寶殿) of Cheoneunsa Buddhist Temple and Daewoongbojeon(大雄寶殿) of Naesosa Buddhist Temple in Jeolla is especially noteworthy in that it bears similar patterns and techniques to that of the main building of Mihwangsa Buddhist Temple in addition to the characteristics mentioned above. The Dancheong of Mihwangsa Buddhist Temple must have exerted so great influences on that of the two temples that it's called "the style of Mihwangsa Buddhist Temple."When adopting a broader point of view, it can be classified as one of the Dancheong styles of Jeolla. The common icons and techniques found in the Dancheong of Mihwangsa, Cheoneunsa, and Naesosa Buddhist Temple provide some clues about the influential relationships among painters of the days. They may have been created by the painters of the same school or the painters affected by those who created the Dancheong of Mihwangsa Buddhist Temple.

• Korean Journal of Heritage: History & Science
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• v.46 no.3
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• pp.114-133
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• 2013

This study aims to identify the natural damage of the Samcheonsaji Temple Site in Bukhansan National Park and to suggest the plans to minimize damage for the remains. The types of natural damage are classified into direct vegetation damage, indirect topographical damage, and artificial damage. The most popular causes of damage to temple sites include the roots of trees as direct vegetation damage and the soil erosion by rain or stream as topographical damage. Direct vegetation damage includes burial remains damaged by the root of trees and vines, but it is often observed that some trees have contributed to protection against collapse. Indirect topographical changes have damaged the ruins by soil erosion caused by floods or typhoons. Vegetation changes due to topographical reasons have also caused damage. Artificial reasons of damage include forestry operations and compaction by hikers. Based on the analysis of the findings, the following could be suggested as plans to resolve these problems: 1. Natural damage occurs slowly due to negligence. Therefore, it could be reduced by forestry improvement, including forest density control through thinning, planting to prevent landslides, maintaining grasslands nearby. 2. Deciduous broadleaf trees can be planted to reduce soil erosion by rainfall. It is necessary to maintain the density of forests at around $0.02{\sim}0.18trees/m^2$. 3. It would be good to grow Quercus spp and Carpinus spp or weaken the community of Robinia pseudoacacia and Pueraria lobata which disturb the ecosystem. Samcheonsaji Temple Site is located in Mt. Bukhan National Park that is a publicly owned property. Therefore, it is constantly maintained for natural preservation and vegetation management could be considered for the preservation of historical remains.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.517-524
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• 2018

The purpose of this study was to investigate the density of thrips, and insecticidal resistance for effective control of Western flower thrips in greenhouse. The presence and density of the thrips was investigated using yellow colored-sticky trap in a cucumber field from May to August in Cheon-an. The results of the investigation revealed the existence of the following thrips species; Frankliniella occidentalis, F. intonsa, Thrips palmi, T. tabaci, Scirtothrips dorsalis, Microcephalothrips abdominalis, and T. nigropilosus. The predominant pest was found to be the western flower thrips. To survey the western flower thrips insecticidal resistance, we established the discriminating concentration (DC), recommended concentration (RC) and $2{\times}$recommended concentration ($2{\times}RC$) of nine insecticides; Emamectin benzoate EC, spinetoram SC, Chlorfenapyr EC, Spinosad SC, Cyantraniliprole EC, Acetamiprid WP, Dinotefuran WG, thiacloprid SC and thiamethoxam SC. The bioassay of about five local populations was conducted using the leaf-dipping method. In all local populations, insecticidal resistance in western flower thrips had not developed in emamectin benzoate EC (RC, $10.8{\mu}L\;L^{-1}$), chlorfenapyr EC (RC, $50.0{\mu}L\;L^{-1}$), spinetoram SC (RC, $25.0mg\;L^{-1}$), and spinosad SC (RC, $50.0mg\;L^{-1}$). However, insecticidal resistance in RC was found to have developed in cyantraniliprole EC (RC, $50.0{\mu}L\;L^{-1}$) and four insecticides of neonicotinoid type. Insecticidal activity of 95% or more was observed in each population when cyantraniliprole EC tested in $2{\times}RC$. However, the neonicotinoid types showed different insecticidal activity in $2{\times}RC$.

• The Journal of Korean Society for Radiation Therapy
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• v.31 no.1
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• pp.7-15
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• 2019

Purpose: The purpose of this study is to evaluate beam delivery accuracy for small sized lung SBRT through experiment. In order to assess the accuracy, Eclipse TPS(Treatment planning system) equipped Acuros XB and radiochromic film were used for the dose distribution. Comparing calculated and measured dose distribution, evaluated the margin for PTV(Planning target volume) in lung tissue. Materials and Methods : Acquiring CT images for Rando phantom, planned virtual target volume by size(diameter 2, 3, 4, 5 cm) in right lung. All plans were normalized to the target Volume=prescribed 95 % with 6MV FFF VMAT 2 Arc. To compare with calculated and measured dose distribution, film was inserted in rando phantom and irradiated in axial direction. The indexes of evaluation are percentage difference(%Diff) for absolute dose, RMSE(Root-mean-square-error) value for relative dose, coverage ratio and average dose in PTV. Results: The maximum difference at center point was -4.65 % in diameter 2 cm size. And the RMSE value between the calculated and measured off-axis dose distribution indicated that the measured dose distribution in diameter 2 cm was different from calculated and inaccurate compare to diameter 5 cm. In addition, Distance prescribed 95 % dose($D_{95}$) in diameter 2 cm was not covered in PTV and average dose value was lowest in all sizes. Conclusion: This study demonstrated that small sized PTV was not enough covered with prescribed dose in low density lung tissue. All indexes of experimental results in diameter 2 cm were much different from other sizes. It is showed that minimized PTV is not accurate and affects the results of radiation therapy. It is considered that extended margin at small PTV in low density lung tissue for enhancing target center dose is necessary and don't need to constraint Maximum dose in optimization.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.591-600
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• 2018

The objective of this study was to determine the changes in phytoplankton and long-term water quality of Juksan-Weir in Yeongsan River that took place between April 2010 and December 2015. The number of species used in this study was 288, which consisted of 6% of Cyanophyta, 26% of Bacillariophyta, 53% of Chlorophyta and the others (15%). The standing crops of phytoplankton ranged from $500cells{\cdot}mL^{-1}-29,950cells{\cdot}mL^{-1}$ with an average of $7,885cells{\cdot}mL^{-1}$. At the two site, 20 dominant genera of found. The dominant genera were 6 of Bacillariophyta, 6 of Cyanophyta, 7 of Chlorophyta and 1 of Cryptophyta. The most dominant genus among the phytoplankton was Stephanodiscus sp. (Total 59%, each 54% and 63%). The most dominant genus among the Cyanophyta was Microcystis sp., which had a cell abundance ratio of 17%. The results of two sites were 21% and 13%, and the upstream was higher than the downstream.

• Korean Journal of Heritage: History & Science
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• v.44 no.1
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• pp.106-121
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• 2011

The number of World Natural Heritage Sites is smaller than that of World Cultural Heritage Sites. As of 2010, the total number of natural sites was 180, which is less than 1/3 of all cultural sites. The reason why the number of natural sites is smaller can be attributed to the evaluating criteria of OUV(outstanding universal value). Only 9 fossil related sites were designated as World Heritage Sites among 180 Natural Sites. This study compares their OUVs including the academic value and characteristics of the 9 World Heritage Sites to provide data and reference for KCDC(Korean Cretaceous Dinosaur Coast) to apply as a World Natural Heritage Site. This study was carried out to obtain information and data on the Wadi Al-Hitan of Egypt which was designated as a World Natural Heritage Site. The study includes field investigation for whale fossils, interviews of site paleontologists and staff, and inspections of facilities. Three factors can likely be attributed to its successful management and operating system. First, there is a system for comprehensive research and a monitoring plan. Secondly, experts have been recruited and hired and professional training for staff members has been done properly. Finally, the Wadi Al-Hitan has developed local resources with specialized techniques for conservation and construction design, which matched well with whale fossils and the environment at the site. The Wadi Al-Hitan put a master plan into practice and achieved goals for action plans. To designate a future World Natural Heritage Site in Korea, it is important to be recognized by international experts including IUCN specialists as the best in one's field with OUV. Full-time regular-status employees for a research position are necessary from the preparation stage for the UNESCO World Heritage Site. Local government and related organizations must do their best to control monitoring plans and to improve academic value after the UNESCO World Heritage Site designation. As we experienced during the designation process of Jeju Volcanic Island and Lava Tubes as the first Korean World Natural Heritage Site, participation by various scholars and specialists need to be in harmony with active endeavors from local governments and NGOs.

• Korean Journal of Heritage: History & Science
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• v.46 no.1
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• pp.290-317
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• 2013

The objectives of this study are to investigate the natural heritage and scientific value of various geosites on Udo Island, and to evaluate the sites as natural monuments and as world natural heritage properties. Udo Island includes a variety of geoheritage sites. Various land forms formed during the formation of the Someori Oreum formed by phreatomagmatic eruptions. The essential elements for the formation of Udo Island are the tuff cone, overflowing lava and overlying redeposited tuff sediments. Various coastal land forms are also present. About 6,000 years B.C., when sea-level rose close to its present level due to deglaciation since the Last Glacial Maximum, carbonate sediments have been formed and deposited in shallow marine environment surrounding Udo Island. In particular, the very shallow broad shelf between Udo Island and Jeju Island, less than 20 m in water depth, has provided perfect conditions for the formation of rhodoids. Significant amounts of rhodoids are now forming in this area. Occasional transport of these rhodoids by typhoons has produced unique beach deposits which are entirely composed of rhodoids. Additional features are the Hagosudong Beach with its white carbonate sands, the Geommeole Beach with its black tuffaceous sands and Tolkani Beach with its basalt cobbles and boulders. Near Hagosudong Beach, wind-blown sands in the past produced carbonate sand dunes. On the northern part of the island, special carbonate sediments are present, due to their formation by composite processes such as beach-forming process and transportation by typhoons. The development of several sea caves is another feature of Udo Island, formed by waves and typhoon erosion within tuffaceous sedimentary rocks. In particular, one sea cave found at a depth of 10 m is very special because it indicates past sea-level fluctuations. Shell mounds in Udo Island may well represent the mixed heritage feature on this island. The most valuable geoheritage sites investigated around Udo Isalnd are rhodoid depostis on beaches and in shallow seas, and Someori Oreum composed of volcanoclastic deposits and basalt lava. Beach and shallow marine sediments, composed only of rhodoids, appear to be very rare in the world. Also, the natural heritage value of the Someori Oreum is outstanding, together with other phreatomagmatic tuff cones such as Suwolbong, Songaksan and Yongmeori. Consequently, the rhodoid deposits and the Someori Oreum are worth being nominated for UNESCO World Natural Heritage status. The designation of Someori Oreum as a Natural Monument should be a prerequisite for this procedure.