• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.804-811
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• 2010

The lower portion of sloping paddy fields normally contains excessive moisture and the higher water table caused by the inflow of ground water from the upper part of the field resulting in non-uniform water content distribution. Four drainage methods namely Open Ditch, Vinyl Barrier, Pipe Drainage and Tube Bundle for multiple land use were installed within 1-m position from the lower edge of the upper embankment of sloping alluvial paddy fields. Knowledge of the spatial variability of soil water properties is of primary importance for management of agricultural lands. This study was conducted to evaluate the effect of drainage in the soil on spatial variability of soil water content using the geostatistical analysis. The soil water content was collected by a TDR (Time Domain Reflectometry) sensor after the installation of subsurface drainage on regular square grid of 80 m at 20 m paddy field located at Oesan-ri, Buk-myeon, Changwon-si in alluvial slopping paddy fields ($35^{\circ}22^{\prime}$ N, $128^{\circ}35^{\prime}$). In order to obtain the most accurate field information, the sampling grid was divided 3 m by 3 m unit mesh by four drainage types. The results showed that spatial variance of soil water content by subsurface drainage was reduced, though yield of soybean showed the same trends. Value of "sill" of soil water content with semivariogram was 9.7 in Pipe Drainage, 86.2 in Open Ditch, and 66.8 in Vinyl Barrier and 15.7 in Tube Bundle.

• Journal of the Korean Society of Earth Science Education
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• v.14 no.2
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• pp.136-145
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• 2021

The Gifted Education Program is re-constructured into core competency-based program in line with fourth industrial revolution, where talented people with comprehensive ability are required. Therefore, competency-based elementary science gifted education program which is provided from Gifted Education Database(GED) is developed in accordance with 2015 revised edition in science and 5 main core-abilities; scientific thinking ability, scientific investigation ability, scientific problem solving ability, scientific communication ability and scientific participation and lifelong learning ability. This research, which is provided from GED, is focused on earth science area among competency-based elementary science gifted education program and analyse quantitatively and qualitatively how science and core-ability is appeared in 3 programs developed in science area. This research can be another guideline when someone would like to use competency-based earth science gifted education program in gifted education. Also, the purpose of this research is to help suggesting a right direction for competency-based earth science gifted education program. The conclusion based on research problem is as follow; Firstly, in competency-based earth science gifted education program, influence rates of scientific communication ability and scientific thinking ability are highest, where influence rates of scientific investigation ability, scientific problem solving ability and scientific participation and lifelong learning ability are relatively low. Secondly, in competency-based earth science gifted education program, single activity may includes several core-abilities. Following research is quite meaningful in aspect of giving out the information to choose topic in core-ability when using competency-based earth science gifted education program in gifted education. Also by supplementing lowly-influenced ability in competency-based earth science gifted education program, it is expected for gifted students to build scientific core-ability.

• Journal of Korean Philosophical Society
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• v.146
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• pp.307-328
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• 2018

The use of thought experiments has a long history in many disciplines including science. In the field of philosophy, thought experiments have frequently appeared in the pre-existing literature on the contemporary Analytic Philosophy. A thought experiment refers to a synthetic environment where the designer of the experiment-with his or her intuition and imagination-tests common-sense knowledge. It can be understood as a conceptual tool for testing the validity of the common understanding of an issue or a phenomenon. However, we are not certain about the usefulness or efficacy of a thought experiment in knowledge production. The design of a thought experiment is meant to lure readers into believing as intended by the experiment itself. Thus, regardless of the purpose of a thought experiment, many readers who encounter the experiment could feel deceived. In this paper, to analyze the logic of thought experiments and to seek the source of uneasiness the readers and critics may feel about thought experiments, I draw lessons from three renowned thought-experiments: Thomson's 'ailing violinist', Putnam's 'brain in a vat', and Searle's 'Chinese room'. Imaginative thought experiments are usually constructed around a gap between the reality and the knowledge/information at hand. From the three experiments, several lessons can be learned. First, the evidence of the existence of a gap provided via thought experiments can serve as arguments for counterfactual situations. At the same time, the credibility and efficacy of the thought experiments can be damaged as soon as the thought-experiments are carried out with inappropriate and/or murky directions regarding the procedures of the experiment or the background of the study. According to D. R. Hofstadter and D. C. Dennett(1981), the 'knob setting' in a thought experiment can be altered in the middle of a simulation of the experimental condition, and then the implications of the thought experiment change altogether, indicating that an entirely different conclusion can be deduced from thought experiment. Lastly, some pre-suppositions and bias of the experiment designers play a considerable role in the validity and the chances of success of a thought experiment; thus, it is recommended that the experiment-designers refrain from exercising too much of their imagination in order to avoid contaminating the design of the experiment and/or wrongly accepting preconceived/misguided conclusions.

• Korean Journal of Heritage: History & Science
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• v.52 no.2
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• pp.122-141
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• 2019

This study aimed to provide new interpretations of the ceramics excavated from the archaeological site of the royal palace of Goryeo (918~1392), where only limited access was permitted due to its location in Gaeseong, North Korea. The interpretations were based on the existing understanding of the arrangement of the palace buildings at the site and historical records. The study of the general aspects of the celadons discovered during eight excavations at the Goryeo Palace site in Gaeseong revealed that most of the vessels found at the site were produced during the early and middle phases of the Goryeo dynasty. The study involved classifying the celadons bearing inscribed texts and symbols into 18 different types according to their characteristic features and periods of production. The inscribed celadons have provided detailed information of the site where they were found, thereby making it possible to make strong presumptions about the date of construction, function, and status of the building in the palace connected with the discoveries. The excavations from the Goryeo Palace site and related historical literature suggest that the celadons bearing the inscription "Sojeon (燒錢)" were used during the first half of the 13th century, although the existing view had been that they were used during the second half of the century. This new conclusion is based on the use of the symbols ${\circ}$ and ${\odot}$, the celadons found together with the Sojeon-inscribed celadons, the date of the celadons bearing the inscription "Seong (成)," and the location of their discovery behind the site of Seongyeongjeon (aka Hoegyeongjeon) Hall, which had been one of the main palace buildings. The Taoist rituals performed for the safety of the Goryeo dynasty were largely held at Ganganjeon (aka Daegwanjeon) Hall in the western part of the royal palace during the second half of the 13th century. It was mostly in the first half of the 13th century just before the transfer of the Goryeo government from Gaeseong to Ganghwa (1232~1270) that the Taoist rituals were held at the location near Seongyeongjeon Hall, where archaeologists found the Sojeon-inscribed celadons. Therefore, the large number of celadon cups with holders, including those inscribed with Sojeon, discovered during the eighth excavation of the palace site suggests that they were used for the rituals held at Seongyeongjeon Hall during the first half of the 13th century.

• Journal of the Korean Society of Radiology
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• v.13 no.2
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• pp.193-200
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• 2019

The study was conducted surveying ultrasound room workers on hospital infection awareness in Daejeon and Choong-chunng region. The contamination of ultrasonic probes used in clinical trials was measured using ATP, and the results were verified after using 70% alcohol sterilization. It was measured on the group's general characteristics and the specific categories such as academic background, job type, having professional certificate and infection education. After the examination, the gel removal and method, disinfection status of the probe and variable correlation analysis were performed to analyze the recognition of the ultrasonic probe disinfection. After examination in ultrasound room, it was found that towels were used the most for cleaning, and the gel container was not replaced for more than three months. After 70% alcohol disinfection, ATP contamination was reduced from $1055.4{\pm}944.2$ to $133.5{\pm}93.2$ and the result was analyzed to be statistically significant.(${\rho}<0.01$) The found bacteria were CNS, Gram positive bacillus, and Micrococcus specs. In order to solve this problem, 70% alcohol sterilization was applied and the bacteria were not detected after the treatment. The research shows that regular training on infection control and efforts to prevent infection are necessary, and that 70% alcohol is effective in disinfect the bacteria. Therefore, the medical institution should provide active hospital infection control education to improve the awareness of hospital infection among workers and contribute to the prevention of patient infection. It is also understood that proper use of the results of this study will help prevent infection by means of ultrasonic probes.

• Tunnel and Underground Space
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• v.31 no.5
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• pp.374-384
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• 2021

In this study, we propose a new approach for automatic fracture detection in CT scan images of rock specimens. This approach is built on top of two-stage object detection deep learning algorithm called Faster R-CNN with a major modification of using rotated bounding box. The use of rotated bounding box plays a key role in the future work to overcome several inherent difficulties of fracture segmentation relating to the heterogeneity of uninterested background (i.e., minerals) and the variation in size and shape of fracture. Comparing to the commonly used bounding box (i.e., axis-align bounding box), rotated bounding box shows a greater adaptability to fit with the elongated shape of fracture, such that minimizing the ratio of background within the bounding box. Besides, an additional benefit of rotated bounding box is that it can provide relative information on the orientation and length of fracture without the further segmentation and measurement step. To validate the applicability of the proposed approach, we train and test our approach with a number of CT image sets of fractured granite specimens with highly heterogeneous background and other rocks such as sandstone and shale. The result demonstrates that our approach can lead to the encouraging results on fracture detection with the mean average precision (mAP) up to 0.89 and also outperform the conventional approach in terms of background-to-object ratio within the bounding box.

• Journal of Korea Water Resources Association
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• v.54 no.9
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• pp.731-745
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• 2021

In this study, the monthly temperature of the Han River basin was predicted by statistical multiple regression models that use global climate indices and weather data of the target region as predictors. The optimal predictors were selected through teleconnection analysis between the monthly temperature and the preceding patterns of each climate index, and forecast models capable of predicting up to 12 months in advance were constructed by combining the selected predictors and cross-validating the past period. Fore each target month, 1000 optimized models were derived and forecast ranges were presented. As a result of analyzing the predictability of monthly temperature from January 1992 to December 2020, PBIAS was -1.4 to -0.7%, RSR was 0.15 to 0.16, NSE was 0.98, and r was 0.99, indicating a high goodness-of-fit. The probability of each monthly observation being included in the forecast range was about 64.4% on average, and by month, the predictability was relatively high in September, December, February, and January, and low in April, August, and March. The predicted range and median were in good agreement with the observations, except for some periods when temperature was dramatically lower or higher than in normal years. The quantitative temperature forecast information derived from this study will be useful not only for forecasting changes in temperature in the future period (1 to 12 months in advance), but also in predicting changes in the hydro-ecological environment, including evapotranspiration highly correlated with temperature.

• MISULJARYO - National Museum of Korea Art Journal
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• v.97
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• pp.55-68
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• 2020

The inscription found on buncheong ware (粉靑沙器, grayish-blue-powdered celadon) provides information on the bowl today, but in the past served as a device for controlling tributary payments (貢納) and the movement of government property (官物). The inscription had to be written or engraved clearly so that it could be recognizable to officials in charge of managing bowls. Such inscriptions offer important clues for contemporary research on buncheong ware. Buncheong Bowl with Stamped Design and Inscription of "Naeja" (內子) (bon 13808) in the collection of the National Museum of Korea bears a distinct inscription compared to other buncheong ware. Commonly, the inscription on buncheong indicated the name of the government office (官司名) to which the vessel belonged or the name of the place (地名) where the vessel was produced. However, the inscription "Naeja" on the buncheong bowl at the National Museum of Korea has no corresponding government office. "Naeja" is in fact a misspelling of Naeja (內資), meaning this bowl belonged to the Naejasi (內資寺, Royal Bureau of Procurement). Although "Naeja" (內子) was a misspelling of the intended Naeja (內資), it was still understood as a reference to the Naejasi since they were homophonic. Recently, buncheong ware with misspelled yet homophonous inscriptions have begun to be excavated in downtown Seoul. Examples including "Naeja" (內子) instead of Naeja (內資) and "Insu" (仁守) instead of Insu (仁壽) have been unearthed from historical sites in Seoul that functioned as consumption sites, meaning they were in fact circulated as government property despite the misspellings (whether accidental or the outcome of ignorance). Such misspelled yet homophonous inscriptions are characterized by the use of simple characters and a few sloppy strokes. Like other buncheong ware bearing the inscriptions of government office names, the bowls with the inscriptions of "Naeja" (內子) and "Insu" (仁守) were discovered at historical sites in Seoul. These misspelled homophonous inscriptions reveal that errors occurred during the process of engraving inscriptions on buncheong ware produced as a tributary payment during the early Joseon Dynasty and that buncheong ware with such errors were still distributed.

• Korean Journal of Heritage: History & Science
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• v.53 no.4
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• pp.118-135
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• 2020

It is not uncommon in Korea to see the structure and function of a garden remain intact as well as its form. Yi Cheon-bo's Historic House (Gyeonggi-do Cultural Heritage Item No. 55), located in Sang-myeon, Gapyeong-gun, Gyeonggi-do, is considered an example of very valuable garden heritage, although its family history, location, and remaining buildings and natural cultural assets are not fully intact. Along with Yi Cheon-bo's Historic House, this study attempted to explore the possibility of restoration of the forest houses and gardens by highlighting the high value of Yi Cheon-bo's Historic House through research into the typical layout of private households in northern Gyeonggi Province and Gapyeong County, comparative review of aerial photographs from 1954, and interviews with those involved. The results of the study are as follows: In this study, the presence of Banggye-dongmun and Bansukam in the Banggyecheon area, where the location of the garden was well-preserved, was examined across the landscape of the outer garden, while the location of Yi Cheon-bo's Historic House, the appearance of feng shui, and the viewing axis were considered. Also, the appearance of the lost main house was inferred from the arrangement and shape of the Sarangchae and Haengrangchae that remain in the original garden, and the asymmetry of the Sarangchae Numaru and the hapgak shape on the side of the roof. In addition, the three tablets (Pyeonaeks) of Sanggodang (尙古堂), Bangyejeongsa (磻溪精舍), and Okgyeongsanbang (玉聲山房) were used to infer the landscape, use, and symbolism of the men's quarters. Also, a survey was conducted on the trees that existed or existed in the high prices. Incidentally, it was confirmed that information on boards and cultural properties of Yeonha-ri juniper (Gyeonggi-do Monument No. 61) was recorded to a much lesser extent than the actual required standard, and the juniper trees remaining in the front of Haengrangchae should also be re-evaluated after speculation. On the other hand, as a result of estimating the original shape as a way of pursuing completeness of the garden through restoration of the lost women's quarters and shrine, it is estimated that the main house was placed in the form of a '口' or a 'be warped 口' on the right (north) side of the men's quarters. By synthesizing these results, a restoration alternative for Yi Cheon-bo's Historic House was suggested.

• Conservation Science in Museum
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• v.26
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• pp.161-182
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• 2021

A jungwangu, a type of medium-sized mortar, is a firearm with a barrel and a bowl-shaped projectileloading component. A bigyeokjincheonroe (bombshell) or a danseok (stone ball) could be used as a projectile. According to the Hwaposik eonhae (Korean Translation of the Method of Production and Use of Artillery, 1635) by Yi Seo, mortars were classified into four types according to its size: large, medium, small, or extra-small. A total of three mortars from the Joseon period have survived, including one large mortar (Treasure No. 857) and two medium versions (Treasure Nos. 858 and 859). In this study, the production method for medium mortars was investigated based on scientific analysis of the two extant medium mortars, respectively housed in the Jinju National Museum (Treasure No. 858) and the Korea Naval Academy Museum (Treasure No. 859). Since only two medium mortars remain in Korea, detailed specifications were compared between them based on precise 3D scanning information of the items, and the measurements were compared with the figures in relevant records from the period. According to the investigation, the two mortars showed only a minute difference in overall size but their weight differed by 5,507 grams. In particular, the location of the wick hole and the length of the handle were distinct. The extant medium mortars are highly similar to the specifications listed in the Hwaposik eonhae. The composition of the medium mortars was analyzed and compared with other bronze gunpowder weapons. The surface composition analysis showed that the medium mortars were made of a ternary alloy of Cu-Sn-Pb with average respective proportions of (wt%) 85.24, 10.16, and 2.98. The material composition of the medium mortars was very similar to the average composition of the small gun from the Joseon period analyzed in previous research. It also showed a similarity with that of bronze gun-metal from medieval Europe. The casting technique was investigated based on a casting defect on the surface and the CT image. Judging by the mold line on the side, it appears that they were made in a piece-mold wherein the mold was halved and using a vertical design with molten metal poured through the end of the chamber and the muzzle was at the bottom. Chaplets, an auxiliary device that fixed the mold and the core to the barrel wall, were identified, which may have been applied to maintain the uniformity of the barrel wall. While the two medium mortars (Treasure Nos. 858 and 859) are highly similar to each other in appearance, considering the difference in the arrangement of the chaplets between the two items it is likely that a different mold design was used for each item.