• Journal of Fisheries and Marine Sciences Education
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• v.3 no.2
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• pp.73-82
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• 1991

In recent years, the communication and the trade between the Republic of Korea(South Korea) and the Communist bloc has been activated. The simultaneous entrance of South Korea and North Korea to the United Nations will accelerate the political dialogue and also the trade which is indirectly carried out through a third country at present will be turned into direct way. Fisheries products are also treated as one of the important trade goods and there is a hopeful prospect that the amount of trade will be steeply increased in the near future. Furthermore, there is a great possibility of development up to the joint utilization of fishing grounds or the joint investment in fisheries projects. Concerning such points, since it is very much important to understand the present status of fisheries in North Korea, the author made a study on this field as requested by the Board of Unification, and report a part of the study here. The prominent character of North Korea's ruling sea area is that the sea is completely separated into two regions-the East Sea Region and the West Sea Region-and no continuity exists between them. The East Sea Region locates in the fringe of the biggest fishing ground of the world-the North Pacific Ocean-and very rich in resources not only warm water fishes but also cold water fishes. Especially alaska pollack, Theragra chalcogramma, is caught abundantly in this region. Contrary to that, fishing activity in the West Sea Region seems to be interrupted in winter. Even though some valuable warm water fishes-yellow corvenia, Pseudosciaena manchurica, and hair tail, Trichiurus lepturus, and so forth-come to this region from spring to summer along the coast line of this region for spawning, and vigorous fishing activity is carried out. But the most of them migrate southward to the neighboring waters of Cheju Island for wintering from autumn to winter, and so the fishing activity in this region seems to be interrupted greatly during winter. The total number of fishing boats in North Korea is estimated at 36 thousand and the rate of mechnization at about 70% compared with 99 thousand and 78% in South Korea. North Korea proclaimed an exclusive economic zone of 200 nautical miles in 1977. Specific character of this zone is setting of military boundary zone, up to 50 miles from the base line in the East Sea Region and also it covers whole region of the economic zone in the West Sea Region. Especially in the East Sea Region she set up a straight base line which can not be permissible by the international law. North Korea's statistics on fisheries product has not been announced officially on account of her unique isolationism, but it can be estimated through several data procured. At the first, the amount of fisheries products in the North Korea is reported as about 1.7 million ${\frac{M}{T}}$ by Fisheries Statistics which issued by the FAO in 1987, but a North Korea's trade organization announced the amount as 3.5 million ${\frac{M}{T}}$ in 1988. The former seems to be underestimated and the latter must be an exaggeration. According to Chikuni, who is a Japanese worker for FAO, prepared the unofficial statistics based on the evidence which he collected through the fineries development plan of the FAO/UNDP, and estimated the mean amount between 1982 and 1984 was 2.4 million ${\frac{M}{T}}$ or so. The Board of Unification estimated on the basis of various factors that the amount was 2.2 million ${\frac{M}{T}}$ or so in 1987 and in 1988. This seems to be the most reasonable. To solve the chronic lack of foreign currency, North Korea makes effort on the development of fisheries, and has even aimed fisheries product at 11 million ${\frac{M}{T}}$ by 1993, but this target looks unrealistic under the present circumstances. Somehow, we can exploit her extreme policy which has gone so far as to establish such an excessive and impractical target. Nevertheless this will be helpful to promote the joint development of the fishery activity between South Korea and North Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.4
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• pp.392-406
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• 1985

The soil management practices before transplanting the ginseng plant were studied with two organic matter sources such as a traditional organic matter (wild grass) and commercial organic fertilizer (byproducts of amino acid fermantation) during the late spring to late autumn. During the soil management practices, the soil received 40kg N/10a from five different combination treatments with above two organic matter sources, a wild grass and a commercial organic fertilizer. After the application of the treatments, the soil were ploughed regularly at the interval of 20 days and the changes of physicochemical properties during the soil management practices were investigated. The next year after soil management practices, ginseng plants were transplanted to each treatment, growth and the content of some organic components of ginseng plant were measured for comparision of the different treatments. 1. The decrease in bulk density observed during the first 40 days of management was considered to be the effect of the improved physical conditions caused by ploughing, The decrease in bulk density observed after 40 days of management was considered to be the effect of organic matter. Similar results were observed in particle density, however porosity increased with time. 2. Soil pH tended to decrease during the first 40 days of management, after which period the pH increased and was stabilized. However, CEC increased with organic matter treatment and the exchangeable $NH^+_4-N$ and $NO^-_3-N$ increased in 20 and 40 days after the management practices, respectively, and after that period it became steady. 3. The decomposition rate of treated organic matter was measured by the incubation test in laboratory conditions. The rate of decomposition was rapid during the first 20 days of management, after which period it showed slight changes. 4. The weight of ginseng root significantly increased in the treatment of 10kg N/10a organic fertilizer and 30kg N/10a wild grass. 5. The saponin content of ginseng root was highest in the 40kg N/10a wild grass treatment. The addition of organic fertilizer at the rate of more than 20kg N/10a caused the decrease in the saponin content.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.3
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• pp.154-162
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• 2003

This study was conducted to investigate the effects of tile drain on Physicochemical properties and crop productivity of soils under plastic film house for three years (1999 - 2001). Tiles (${\Phi}100mm$ PVC pipe) were established at 50-60 cm depth with 1 m, 2 m, and 3 m intervals in Gangseo silt loam soil under 2W-type plastic film house. Cropping system was a pumpkin-pumpkin in the first year, a cucumber-spinach-crown daisy-spinach-young radish in the second year, and a green red pepper-tomato-spinach in last year, with conventional fertilization and drip or furrow irrigation by groundwater pumping. Bulk density and soil hardness of plot with tile drain were lower than those of control (plot without tile drain). Soil water content was also lower in tile drain plot than in control regardless of soil depth, and decreased at narrower interval and longer distance from tile in the same plot, thus suggesting that water flow and density of tile drain plot was higher than those of control. Rhizosphere of spinach, a final crop of third year, was expanded more than 2 cm due probably to improvement of soil physical properties caused by tiles establishment. Electrical conductivity (EC) of topsoil decreased from $1.22dS\;m^{-1}$ to $0.82dS\;m^{-1}$ by tile drain system, and the extent of EC decrease was different with season: higher in spring and lower in summer and autumn. The $NO_{3^-}-N$ concentration in topsoil decreased, from $200mg\;kg^{-1}$ to $39mg\;kg^{-1}$. The effect of tile drain on crop yield varied with crops. Average crop productivity obtained in tile drain plot than that of control crop: 18.2% in 2 m interval, 14.2% in 3 m interval, but lower 0.2% in 1 m interval.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.688-695
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• 2011

This study was carried out for some survey about soil compaction in the multi-cropping system of paddy field. Investigated sites were 90 farmer's fields in south-eastern part of Korea. The tillage practices season was different according to cropping system of paddy; in spring for mono rice cultivation and in autumn for the multi-cropping field. The average tillage depth in investigated sites was about 25 cm, however, it is different between the farmer's tillage practices and soil characteristics. It is high correlation to tillage deep and minimum resistance of penetration. The reaching soil deep to maximum resistance of penetration was about 27 cm, and average penetration resistance of the deep is 1.8~2.0 MPa for moderately fine-textured soils and more than 3.0 MPa for moderately coarse-textured soils. The difference of penetration resistance between cultivating and compacted layer was in order to sandy loam > clayey loam > clayey, and the difference was lesser in poorly drained soils than somewhat poorly ones. In the rice mono cropping field, the maximum resistance in no-tillage for 15 years was 1.18~1.25 Mpa at 20~25 cm in soil deep, however, the resistance of field with every year tillage practices was 2.03~2.21 Mpa. In the extremely compacted sandy loam textured soils, the penetration resistance at 30 cm in soil depth was drastically reduced by the subsoil from 5.2 Mpa to 3.2 Mpa, and the watermelon root in plastic film house was deep elongated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.3
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• pp.256-264
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• 2021

Rapeseed (Brassica napus L.) is generally sown in late autumn and harvested in early summer in Korea, however, spring cultivation has also been attempted in some areas because frequent climate changes induce reducing productivity. Therefore, there is a need for a transplanting technology that is relatively easy to control of cropping season according to changes in cultivation conditions. In this study, to find out the optimal characteristics of seedlings for machine transplanting of spring cultivation, seedling morphological characteristics were investigated according to the seedling age of three varieties for 2020 and 2021. The hypocotyl length was less than 2 cm in both years and the 40-day-old seedling was the shortest among all seedling ages. The number and size of leaf were increased with longer seedling age in both years. To evaluate seedling quality, total seedling length, seedling weight, and impact resistance were measured before transplanting. Total seedling length was the longest in 40-day-old seedlings and the shortest in 25-day-old seedlings in both years. In the case of seedling weight, no significant differences were observed depending on the seedling age and the impact resistance increased with increasing seedling age. Finally, 'Jungmo7001', 'Naehan', and 'Tamla' showed a high transplanting rate in seedlings grown for more than 30 days, 35 days, and 40 days, respectively, in the field using a general transplanter. These results suggest that the proper seedling age for transplanting is limited depending on the rapeseed varieties. The suitable seedling cultivation method can be selected for different cultivation environments.

• Korean Journal of Remote Sensing
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• v.37 no.6_2
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• pp.1849-1858
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• 2021

We analyzed the monthly and annual trends of the meteorological factors(wind speeds and directions and air temperatures) measured at an automated synoptic observation system (ASOS) and fine particle (PM₁₀ and PM_2.5) concentrations measured at the air quality monitoring systems(AQMSs) in Suwon. In addition, we investigated how the fine particle concentrations were related to the meteorological factors as well as urban morphological parameters (fractions of building volume and road area). We calculated the total volume of buildings and the total area of the roads in the area of 2 km × 2 km centered at each AQMS using the geographic information system and environmental geographic information system. The analysis of the meteorological factors showed that the dominant wind directions at the ASOS were westerly and northwesterly and that the average wind speed was strong in Spring. The measured fine particle concentrations were low in Summer and early Autumn (July to September) and high in Spring and Winter. In 2020, the annual mean fine particle concentration was lowest at most AQMSs. The fine particle concentrations were negatively and weakly correlated with the measured wind speeds and air temperatures (the correlation between PM_2.5 concentrations and air temperatures was relatively strong). In Suwon city, at least for 6 AQMSs except for the RAQMS 131116 and AQMS 131118, the PM₁₀ concentrations were affected mainly by the transport from outside rather than primary emission from mobile sources or wind speed decrease caused by buildings and, in the case of PM_2.5, vise versa.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.1043-1059
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• 2021

Forest and agricultural land are very important factors in the environmental ecosystem and securing food resources. Forest and agricultural land should be monitored regularly. CAS500-4 data are expected to be effectively used as a supplement of monitoring forest and agricultural land. Prior to the launch of the CAS500-4, the relative canopy height error analysis of the digital elevation model on South Korea was performed to determine the vertical target accuracy. Especially, by considering area of interest of the CAS500-4 (mountainous or agricultural area), it is conducted that vertical error analysis according to the slope and canopy. For Gongju, Jeju, and Samcheok, the average root mean squared differences were calculated compared to the drone LiDAR digitalsurface models, which were filmed in autumn and winter and the 5 m digital elevation model from the National Geographic Information Institute. As a result, the Shuttle radar topography mission digital elevation model showed a root mean squared differences of about 8.35, 8.19, and 7.49 m, respectively, while the Copernicus digital elevation model showed a root mean squared differences of about 5.65, 6.73, and 7.39 m, respectively. In addition, the root mean squared difference of shuttle radar topography mission digital elevation model and the Copernicus digital elevation model according to the slope angle were estimated on South Korea compared to the 5 m digital elevation model from the National Geographic Information Institute. At the slope angle of between 0° to 5°, root mean squared differences of the Shuttle radar topography mission digital elevation model and the Copernicus digital elevation model showed 3.62 and 2.52 m, respectively. On the other hands root mean squared differences of the Shuttle radar topography mission digital elevation model and the Copernicus digital elevation model respectively showed about 10.16 and 11.62 m at the slope angle of 35° or higher.

• Journal of Korean Philosophical Society
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• v.131
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• pp.199-222
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• 2014

This essay aims at clarifying Dasan Jeong Yagyong's view on Jingfang's yaobian theory. As is well known, Jingfang was a scholar of the Earlier Han period who exerted a profound influence on the theoretical development of Xiangshu School by creating the various techniques for interpreting the Zhouyi. Jingfang is also important in relation with Dasan's commentary of the Zhouyi, because some part of Dasan's interpreting techniques are thought to have their origin in Jinfang. For example, Dasan used the bigua theory of which the origin could be traced back into Jingfang. However, in this article, I did not deal with the bigua theory because I am going to write another article about it. In stead, my focus will be put on analyzing how Dasan evaluated Jingfang's yaobian theory. The main issues of my argument can be summarized as following. Firstly, in terms of yaobian, Jeong Yagyong called attention to Jingfang's annotation on the Zhouyi in which Jingfang utilized the yaobian method in three occasions, i.e., the first nine of the Qian(乾初九), the sixth nine of the Guan(觀上九), and the sixth nine of the Bo(剝上九). It seems that Jeong Yagyong set forth enough evidence about Jingfang's use of yaobian at least in relation to two cases of the first nine of the Qian and the sixth nine of the Bo, while the other evidence of the sixth nine of the Guan was not so persuasive. However, even if it is evident that Jingfang made use of the yaobain in two cases, there is no reason to equate it with that of Dasan. If one takes a close look, it becomes clear that Jingfang's way of yaobain is very different from Dasan's. Secondly, Jeong Yagyong mentioned Jiayi(賈誼) who lived about one hundred years before Jingfang, as the person who utilized the yaobian in his book of Xinshu(新書). If it is certain that Jiayi was aware of the yaobian, we can assume that the yaobian technique had been handed down from Jiayi to Jingfang. The manuscript excavated from the Mawangdui tomb also increases the possibility that Jiayi could have had the knowledge on the yaobian. In the chapter of Muhe(繆和) of the Mawangdui Zhouyi, there appears the phrase, i.e., "the first six of the qian, qian goes to mingyi," which shows exactly the same form of the yaobian in the Mr Zuo's Spring and Autumn Annals(春秋左氏傳). The burial period of Mawangdui tomb is estimated at the same year of B.C.168 in which Jiayi died. Therefore, judging from that fact, it becomes evident that the yaobain method was widely diffused around B.C.168. Subsequently, it is possible to infer that the yaobian method had been handed down from the period of Jiayi to Jingfang. If we could present the persuasive evidence to support that inference, it would also have the effect of consolidating Dasan's argument about the yaobian.

• (The) Research of the performance art and culture
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• no.36
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• pp.751-781
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• 2018

Task of circling the pagoda of Waljeongsa(Woljeongsa Tabdori) is the major intangible cultural heritage with representativeness and historical meaning as a Buddhism culture, one of the Buddhism folk plays, which was firstly played after the liberation. Woljeongsa Tabdori holds significant designation importance in terms of Buddhism folklore heritage with Korean unique tradition and identity of Gangwon-do province. Temples are demonstrating Tabdori nationwide but Woljeongsa Tabdori is the unique case that systematically inherits the culture based on the designation of being intangible cultural heritage. That is why it is needed to focus on the cultural and internal value of Woljeongsa Tabdori. Tabdori is the integrated symbol of Buddhism respect and worship to the Buddha and pagoda. It is hard to presume the originality of Woljeongsa Tabdori: given the history of Woljeonsa temple, it lies into Goguryeo traditional play and Bokhui(Pagoda circling folk play) in Silla era. It fits into the courtesy of Circumambulating Stupa considering Moon in Goguryo mural, background of Odaesan Hwaeom thought/tripitaka and essence of Octagonal 9-story stone pagoda. At the first stage of Tabdori, Buddhist musical instruments such as Buddhism temple bell, singing bowl, cloud-shaped gong and wooden-fish. However, later, Samhyeon Yukgak has been added and then, Boyeom and Bakpaljeongjinga were singing: it could be interpreted that it was a pure Buddhist ceremony but it has become to have traditional aspect and been spread to the public. The origin of Woljeongsa Tabdori is related to the explanation of Circumambulating Stupa that experiences the glory of the ending ceremony. When a temple has a rite, the Buddhists make an offering to the Buddha. At that time, Buddhist prayer, sermon and chant are followed. After the rite, the Buddhists are circling the pagoda with the monks while praying for Buddhist charity and making their own wishes. It prays not only going after death to Nirvana of the one but also national prosperity and the welfare of the people for peaceful reign. As the temple holds bigger rites, many Buddhists gather and the Tabdori was a success. The scene of circling the pagoda and making own wishes in line with the Buddhist sermon was solemn. The idea on changes and convergence of Woljeongsa Tabdori requires strategic inheritance to promote the transmission while maintaining the paragon and purpose of designating the cultural heritage and reviving its identity. Korean Tabdori was held in Buddha's birthday in April and the mid-autumn day. Tabdori is a memorial service type Buddhist ceremony that once the monk holds the Buddhist rosary, circles the pagoda and sings the great mind and charity of the Buddha, Buddhists follow the step, lighting the lantern, circling the pagoda and praying for the gentle and easy death. Transmission education of the successor, diversified approach of the expert's advice and discourse on the revival of the origin should be reinforced in phases.

• Journal of Ecology and Environment
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• v.42 no.4
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• pp.210-218
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• 2018

Background: Soil respiration (Rs) is a major factor of the absorption and accumulation of carbon through photosynthesis in the ecosystem carbon cycle. This directly affects the amount of net ecosystem productivity, which affects the stability and sustainability of the ecosystem. Understanding the characteristics of Rs is indispensable to scientifically understand the carbon cycle of ecosystems. It is very important to study Rs characteristics through analysis of environmental factors closely related to Rs. Rs is affected by various environmental factors, such as temperature, precipitation, soil moisture, litter supply, organic matter content, dominant plant species, and soil disturbance. This study was conducted to analyze the effects of micro-topographical differences on Rs in forest vegetation by measuring the Rs on the ridge and southern slope sites of the broadly established Quercus mongolica forest in the central Korean area. Method: Rs, Ts, and soil moisture data were collected at the southern slope and ridge of the Q. mongolica forest in the Mt. Jeombong area in order to investigate the effects of topographical differences on Rs. Rs was collected by the closed chamber method, and data collection was performed from May 2011 to October 2013, except Winter seasons from November to April or May. For collecting the raw data of Rs in the field, acrylic collars were placed at the ridge and southern slope of the forest. The accumulated surface litter and the soil organic matter content (SOMC) were measured to a 5 cm depth. Based on these data, the Rs characteristics of the slope and ridge were analyzed. Results: Rs showed a distinct seasonal variation pattern in both the ridge and southern slope sites. In addition, Rs showed a distinct seasonal variation with high and low Ts changes. The average Rs measurements for the two sites, except for the Winter periods that were not measured, were $550.1\;mg\;CO_2m^{-2}h^{-1}$ at the ridge site and $289.4\;mg\;CO_2m^{-2}h^{-1}$ at the southern slope, a difference of 52.6%. There was no significant difference in the Rs difference between slopes except for the first half of 2013, and both sites showed a tendency to increase exponentially as Ts increased. In addition, although the correlation is low, the difference in Rs between sites tended to increase as Ts increased. SMC showed a large fluctuation at the southern slope site relative to the ridge site, as while it was very low in 2013, it was high in 2011 and 2012. The accumulated litter of the soil surface and the SOMC at the depth range of 0~5 cm were $874g\;m^{-2}$ and 23.3% at the ridge site, and $396g\;m^{-2}$ and 19.9% at the southern slope site. Conclusions: In this study, Rs was measured for the ridge and southern slope sites, which have two different results where the surface litter layer is disturbed by strong winds. The southern slope site shows that the litter layer formed in autumn due to strong winds almost disappeared, and while in the ridge site, it became thick due to the transfer of litter from the southern slope site. The mean Rs was about two times higher in the ridge site compared to that in the southern slope site. The Rs difference seems to be due to the difference in the amount of litter accumulated on the soil surface. As a result, the litter layer supplied to the soil surface is disturbed due to the micro-topographical difference, as the slope and the change of the community structure due to the plant season cause heterogeneity of the litter layer development, which in turn affects SMC and Rs. Therefore, it is necessary to introduce and understand these micro-topographical features and mechanisms when quantifying and analyzing the Rs of an ecosystem.