• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.19-19
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• 2022

Hulled and naked oat is a perspective crop for the low input production systems due to its low requirements for soil quality and nutrition. Oats have good competitive ability against weeds and can provide appropriate yield in organic farming in comparison with other cereal species such as wheat or barley. It is a perspective crop from the point of view of use in the food industry too. The aim of our study was to compare the production and quality parameters of naked and hulled oat grown in both organic (OF) and conventional fields (CF). Small plot trials were conducted in two locations in the Czech Republic (České Budějovice, Prague) for four years (2018-2021) in two production systems (OF, and CF). We used four varieties of hulled oat (Korok, Kertag, Raven, Seldon) and one variety of naked oat (Patrik). During the vegetation, agronomically important data were recorded. After harvest samples were processed in the laboratory and analyzed selected quality parameters of grain dry matter (the protein content was determined by the Kjeldahl method, starch content in grain according to Ewers, fat content in grain dry matter by the modified method according to Soxhlet, and ash content in grain dry matter). The data were evaluated using the program STATISTICA version 13.2, StatSoft, Inc., California, USA. It is clear from the results that the number of panicles before the harvest was influenced by the location, cultivation system, year, and, to a lesser extent, the influence of the variety. The number of panicles in OF averaged 340 per square meter, which was 90% of the value of CF. For thousand grain weight (TGW), a significantly predominant effect of year was found. The independent effect of location on TGW was statistically not significant. Grain yield was predominantly influenced by cultivation system and location. In OF, it reached an average of 3.97 t.ha^-1, which was 75% of the yield of CF. As part of the evaluation of the basic grain quality indicators, the content of protein, starch, fat, and ash in the dry matter of the grain was evaluated. The content of protein in the dry matter of the grain was predominantly influenced by year, followed by the influence of the variety and a fairly comparable influence of the cultivation system and locality. On average, it achieved 16.05% in OF and 17.01% in CF. The starch content was then related to the protein content, where as a result of the lower protein content in the grain of OF oats, the content of starch and fat was on the contrary increased. The year turned out to be the most significant factor, affecting both the starch content in the dry matter of the grain and the fat content. This was followed again by a fairly comparable influence on the cultivation system and locality. The influence of the cultivation system and location was not statistically significantly applied in the case of ash content in dry matter. Based on our results we can propose both types of oat (hulled and naked) as perspective crops for OF. An organic farmer can expect to achieve stable yields which, in less favorable conditions for the production of cereals in the OF, may be close to the level of conventional yields. In the future, it will be important to change agrotechnology in OF and increase oat yield because this crop has a good potential to grow in areas with low nitrogen input or less fertile soil.

• Korean Journal of Remote Sensing
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• v.39 no.5_3
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• pp.1009-1029
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• 2023

Urban trees play a vital role in urban ecosystems,significantly reducing impervious surfaces and impacting carbon cycling within the city. Although previous research has demonstrated the efficacy of employing artificial intelligence in conjunction with airborne light detection and ranging (LiDAR) data to generate urban tree information, the availability and cost constraints associated with LiDAR data pose limitations. Consequently, this study employed freely accessible, high-resolution multispectral satellite imagery (i.e., Sentinel-2 data) to estimate fractional tree canopy cover (FTC) within the urban confines of Suwon, South Korea, employing machine learning techniques. This study leveraged a median composite image derived from a time series of Sentinel-2 images. In order to account for the diverse land cover found in urban areas, the model incorporated three types of input variables: average (mean) and standard deviation (std) values within a 30-meter grid from 10 m resolution of optical indices from Sentinel-2, and fractional coverage for distinct land cover classes within 30 m grids from the existing level 3 land cover map. Four schemes with different combinations of input variables were compared. Notably, when all three factors (i.e., mean, std, and fractional cover) were used to consider the variation of landcover in urban areas(Scheme 4, S4), the machine learning model exhibited improved performance compared to using only the mean of optical indices (Scheme 1). Of the various models proposed, the random forest (RF) model with S4 demonstrated the most remarkable performance, achieving R² of 0.8196, and mean absolute error (MAE) of 0.0749, and a root mean squared error (RMSE) of 0.1022. The std variable exhibited the highest impact on model outputs within the heterogeneous land covers based on the variable importance analysis. This trained RF model with S4 was then applied to the entire Suwon region, consistently delivering robust results with an R² of 0.8702, MAE of 0.0873, and RMSE of 0.1335. The FTC estimation method developed in this study is expected to offer advantages for application in various regions, providing fundamental data for a better understanding of carbon dynamics in urban ecosystems in the future.

• MISULJARYO - National Museum of Korea Art Journal
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• v.96
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• pp.89-122
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• 2019

In this paper, I argue that the Handscroll of a Sightseeing Trip to the Hangang and Imjingang Rivers by Jeong Su-yeong (1743~1831, pseudonym: Jiwujae) is a record of his private journeys to several places on the outskirts of Hanyang (present-day Seoul) and that it successfully embodies the painter's subjective perspective while boating on these rivers and going on outings to nearby mountains. Around 1796, Jeong Su-yeong traveled to different places and documented his travels in this 16-meter-long handscroll. Several leaves of paper, each of which depicts a separate landscape, are pieced together to create this long handscroll. This indicates that the Handscroll of a Sightseeing Trip to the Hangang and Imjingang Rivers reflected the painter's personal subjective experiences as he went along his journey rather than simply depicts travel destinations. The Handscroll of a Sightseeing Trip to the Hangang and Imjingang Rivers features two types of travel: boating and mountain outings on foot. Traveling by boat takes up a large portion of the handscroll, which illustrates the channels of the Hangang and Imjingang Rivers. Mountain outings correspond to the sections describing the regions around Bukhansan, Gwanaksan, and Dobongsan Mountains. Jeong Su-yeong traveled to this wide span of places not just once, but several times. The fact that the Hangang River system are not presented in accordance with their actual locations shows that they were illustrated at different points. After visiting the riversides of the Hangang and Namhangang Rivers twice, Jeong Su-yeong delineated them in fourteen scenes. Among them, the first eight illustrate Jeong's initial trip by boat, while the other six scenes are vistas from his second trip. These fourteen scenes occupy half of this handscroll, indicating that the regions near the Hangang River are painted most frequently. The scenes of Jeong Su-yeong's first boating trip to the system of the Hangang River portray the landscapes that he personally witnessed rather than famous scenes. Some of the eight scenic views of Yeoju, including Yongmunsan Mountain, Cheongsimru Pavilion, and Silleuksa Temple, are included in this handscroll. However, Jeong noted spots that were not often painted and depicted them using an eye-level perspective uncommon for illustrating famous scenic locations. The scenes of Jeong's second boating trip include his friend's villa and a meeting with companions. Moreover, Cheongsimru Pavilion and Silleuksa Temple, which are depicted in the first boating trip, are illustrated again from different perspectives and in unique compositions. Jeong Su-yeong examined the same locations several times from different angles. A sense of realism is demonstrated in the scenes of Jeong's first and second boating trips to the channels of the Hangang River, which depict actual roads. Furthermore, viewers can easily follow the level gaze of Jeong from the boat. The scenes depicting the Imjingang River begin from spots near the Yeongpyeongcheon and Hantangang Rivers and end with places along the waterways of the Imjingang River. Here, diverse perspectives were applied, which is characteristic of Imjingang River scenes. Jeong Su-yeong employed a bird's-eye perspective to illustrate the flow of a waterway starting from the Yeongpyeongcheon River. He also used an eye-level perspective to highlight the rocks of Baegundam Pool. Thus, depending on what he wished to emphasize, Jeong applied different perspectives. Hwajeogyeon Pond located by the Hantangang River is illustrated from a bird's-eye perspective to present a panoramic view of the surroundings and rocks. Similarly, the scenery around Uhwajeong Pavilion by the Imjingang River are depicted from the same perspective. A worm's-eye view was selected for Samseongdae Cliff in Tosangun in the upper regions of the Imjingang River and for Nakhwaam Rock. The scenes of Jeong Su-yeong's mountain outings include pavilions and small temple mainly. In the case of Jaeganjeong Pavilion on Bukhansan Mountain, its actual location remains unidentified since the pavilion did not lead to the route of the boating trip to the system of the Hangang River and was separately depicted from other trips to the mountains. I speculate that Jaeganjeong Pavilion refers to a pavilion either in one of the nine valleys in Wooyi-dong at the foot of Bukhansan Mountain or in Songajang Villa. Since these two pavilions are situated in the valleys of Bukhansan Mountain, their descriptions in written texts are similar. As for Gwanaksan Mountain, Chwihyangjeong and Ilganjeong Pavilions as well as Geomjisan Mountain in the Bukhansan Mountain range are depicted. Ilganjeong Pavilion was a well-known site on Gwanaksan that belonged to Shin Wi. In this handscroll, however, Jeong Su-yeong recorded objective geographic information on the pavilion rather than relating it to Shin Wi. "Chwihyangjeong Pavilion" is presented within the walls, while "Geomjisan Mountain" is illustrated outside the walls. Handscroll of a Sightseeing Trip to the Hangang and Imjingang Rivers also includes two small temples, Mangwolam and Okcheonam, on Dobongsan Mountain. The actual locations of these are unknown today. Nevertheless, Gungojip (Anthology of Gungo) by Yim Cheonsang relates that they were sited on Dobongsan Mountain. Compared to other painters who stressed Dobong Seowon (a private Confucian academy) and Manjangbong Peak when depicting Dobongsan Mountain, Jeong Su-yeong highlighted these two small temples. Jeong placed Yeongsanjeon Hall and Cheonbong Stele in "Mangwolam small temple" and Daeungjeon Hall in front of "Okcheonam small temple." In addition to the buildings of the small temple, Jeong drew the peaks of Dobongsan Mountain without inscribing their names, which indicates that he intended the Dobongsan peaks as a background for the scenery. The Handscroll of a Sightseeing Trip to the Hangang and Imjingang Rivers is of great significance in that it embodies Jeong Su-yeong's personal perceptions of scenic spots on the outskirts of Hanyang and records his trips to these places.

• Korean Journal of Ecology and Environment
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• v.37 no.2 s.107
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• pp.180-192
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• 2004

This study was carried out to assess the seasonal variation of water quality and the effect of pollutant loading from watershed in a shallow eutrophic reservoir (Shingu reservoir) from November 2002 to February 2004, Stable thermocline which was greater than $1^{\circ}C$ per meter of the water depth formed in May, and low DO concentration (< 2 mg $O_2\;L^{-1}$) was observed in the hypolimnion from May to September, 2003. The ratio of euphotic depth to mixing depth ($Z_{eu}/Z_{m}$) ranged 0.2 ${\sim}$ 1.1, and the depth of the mixed layer exceeded that of the photic layer during study period, except for May when $Z_{eu}$ and $Z_{m}$ were 4 and 4.3 m, respectively. Most of total nitrogen, ranged 1.1 ${\sim}$ 4.5 ${\mu}g\;N\;L^{-1}$, accounted for inorganic nitrogen (Avg, 58.7%), and sharp increase of $NH_3$-N Hand $NO_3$-N was evident during the spring season. TP concentration in the water column ranged 43.9 ${\sim}$ 126.5 ${\mu}g\;P\;L^{-1}$, and the most of TP in the water column accounted for POP (Avg. 80%). During the study period, DIP concentration in the water column was &;lt 10 ${\mu}g\;P\;L^{-1}$ except for July and August when DIP concentration in the hypolimnion was 22.3 and 56.7 ${\mu}g\;P\;L^{-1}$, respectively. Increase of Chl. a concentration observed in July (99 ${\mu}g\;L^{-1}$) and November 2003 (109 ${\mu}g\;L^{-1}$) when P loading through two inflows was high, and showed close relationship with TP concentration (r = 0.55, P< 0.008, n = 22). Mean Chl. a concentration ranged from 13.5 to 84.5 mg $L^{-1}$ in the water column, and the lowest and highest concentration was observed in February 2004 (13.5 ${\pm}$ 1.0 ${\mu}g\;L^{-1}$) and November 2003 (84.5 ${\pm}$29.0 ${\mu}g\;L^{-1}$), respectively. TP concentration in inflow water increased with discharge (r = 0.69, P< 0.001), 40.5% of annual total P loading introduced in 25 July when there was heavy rainfall. Annual total P loading from watershed was 159.0 kg P $yr^{-1}$, and that of DIP loading was 126.3 kg P $yr^{-1}$ (77.7% of TP loading. The loading of TN (5.0ton yr-1) was 30 times higher than that of TP loading (159.0 kg P yr-1), and the 78% of TN was in the form of non-organic nitrogen, 3.9 ton $yr^{-1}$ in mass. P loading in Shingu reservoir was 1.6 g ${\cdot}$ $m^{-2}$ ${\cdot}$ $yr^{-1}$, which passed the excessive critical loading of Vollenweider-OECD critical loading model. The results of this study indicated that P loading from watershed was the major factor to cause eutrophication and temporal variation of water quality in Shingu reservoir Decrease by 71% in TP loading (159 kg $yr^{-1}$) is necessary for the improvement of mesotrophic level. The management of sediment where tine anaerobic condition was evident in summer, thus, the possibility of P release that can be utilized by existing algae, may also be considered.