• Journal of Space Technology and Applications
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• v.2 no.1
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• pp.41-51
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• 2022

CubeSat is a satellite platform that is widely used not only for earth observation but also for space exploration. CubeSat is also used in magnetic field investigation missions to observe space physics phenomena with various shape configurations of magnetometer instrument unit. In case of magnetic field measurement, the magnetometer instrument should be far away from the satellite body to minimize the magnetic disturbances from satellites. But the accommodation setting of the magnetometer instrument is limited due to the volume constraint of small satellites like a CubeSat. In this paper, we investigated that the magnetic field interference generated by the cube satellite was analyzed how much it can affect the reliability of magnetic field measurement. For this analysis, we used a reaction wheel and Torque rods which have relatively high-power consumption as major noise sources. The magnetic dipole moment of these parts was derived by the data sheet of the manufacturer. We have been confirmed that the effect of the residual moment of the magnetic torque located in the middle of the 3U cube satellite can reach 36,000 nT from the outermost end of the body of the CubeSat in a space without an external magnetic field. In the case of accurate magnetic field measurements of less than 1 nT, we found that the magnetometer should be at least 0.6 m away from the CubeSat body. We expect that this analysis method will be an important role of a magnetic cleanliness analysis when designing a CubeSat to carry out a magnetic field measurement.

• Journal of Daesoon Thought and the Religions of East Asia
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• v.2 no.2
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• pp.33-50
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• 2023

'Fasting of the Mind (心齋, ch. xīn zhāi)' is arguably the most important concept within the practical approach to the spiritual cultivation formulated by the Daoist philosopher, Zhuangzi (莊子). Most scholars have interpreted 'Fasting of the Mind' as an apophatic practice centered around the aim of the 'Dissolution of the Self (喪我, ch. sàng wŎ).' The Korean new religious movement, Daesoon Jinrihoe (大巡眞理會), can be shown to instead consistently utilize cataphatic descriptions of spiritual cultivation based on the 'quieting of the mind (安心, kr. anshim)' and 'quieting of the body (安身, kr. anshin)' with the highest attainable state referred to as the 'Perfected State of Unification with the Dao (道通眞境, kr. Dotong-jingyeong).' While the language used by Zhuangzi and Daesoon Jinrihoe appears quite different on a superficial level, a deeper examination shows that these rhetorical framings are likely negativistic and positivistic descriptions of the same, or at least reasonably similar, phenomena. Zhuangzi, who focused primarily on the body, mind, and internal energy, cautioned practitioners that 'mere listening stops with the ears (聽止於耳, ch. tīng zhǐ yú ěr)' and 'mere recognition stops with the mind (心止於符, ch. xīn zhǐ yú fú).' He therefore encouraged cultivators of the Dao to 'listen with the spirit (聽之以氣 ch. tīng zhī yǐ qì).' The main scripture of Daesoon Jinrihoe states that "The mind is a pivot, gate, and gateway for gods; They, who turn the pivot, open, and close the gate, and go back and forth through the gateway, can be either good or evil (心也者, 鬼神之樞機也, 門戶也,道路也)," and the Supreme God of the Ninth Heaven (九天上帝, kr. Gucheon Sangje) even promises to visit anyone who possesses a 'singularly-focused mind (一心, kr. il-shim).' In both these approaches, there is a sense of what must be kept out of the mind (e.g., external disturbances, strong emotions, malevolent entities) and what the mind should connect with to attain spiritual progress (e.g., spirit, singular focus, the Supreme God). The observations above serve as the main basis for a comparison between the apophatic descriptions of cultivation found in Zhuangzi and their cataphatic counterparts in Daesoon Thought. However, the culmination of this nuanced comparative exploration reveals that while the leanings of Zhuangzi and Daesoon Thought generally hold true, ultimately, both systems of cultivation transcend the categories of apophatic and cataphatic.

• Journal of the Korean earth science society
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• v.45 no.3
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• pp.224-238
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• 2024

This study analyzed lineaments and fault-related landforms in Chungcheongnam-do, central Korean Peninsula, based on historical and instrumental records, given its susceptibility to future earthquakes. We extracted 151 lineaments associated with fault-related landforms. In regions with the Dangjin and Yesan faults, lineaments with strikes matching these faults were densely distributed. Conversely, in the Hongseong Fault area, the number of lineaments was smaller, and those with strikes similar to the fault were less discernible. This is likely due to the extensive distribution of alluvium and surface deformation from long-term weathering, erosion, and cultivation, which obscures geomorphic evidence of faults. At five key fault points, we identified fault-related landforms, such as fault saddles, knickpoints in Quaternary alluvium, and linear valleys, along the lineament, which may indicate an actual fault. However, the displacements of the Quaternary layer within the lineaments appear to be influenced more by external factors, such as artificial disturbances (e.g., cultivation) or stream erosion, than by direct fault movement. The differences between the fault-related landforms in this study area and those in the southeastern Korean Peninsula suggest a specific relationship between fault types and their associated landforms.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.6
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• pp.576-585
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• 1991

General procedures of seed preparation as conventional guide had been established in China before most of Korean literature documented them. ‘Chwijongbeob’ (method of seed select) was to select good quality of seeds and to discard the rest. In ‘Seonjongbeob’ (method of seed grading) although China employed only ‘Sooseonbeob’ (method of seed select with water), but seeds were selected in order of selection of seeds by winds, selection of seeds by sieve and selection of seed with water in Korea. As compared with the recent techniques, those methods were perfect techniques for selection of good quality seeds of rice, except for method of seed selection by salt water was developed. The method for measurement of seed moisture, and for measurement of melted snow, spoiled urine and extracted juice by boiling water with the bone of livestock were originated from ancient China. The farming books in Korea were more or less followed the above methods. However, these techniques were complicated and impractical interms of validity and rationality. Also, it is judged that these tchniques are more appropriate in dry areas and alkaline soil of China rather than in Korean conditions. The plowing is a work to begin farming, and is operated for air ventilation between atmosphere and earth. Also, this techniques was adopted in the farming books from the early to the late Chosun dynasty without changes. Fields were deep-plowed in the first, in fall (or in spring) and for cultivation, and were shallow -plowed in the second, in spring (or in summer) and in intertillage. The former was for water reserve and land preparation, and the later was for weed control with intertillage. However, plowing in fall which was different from fallowing in dry areas, was recommended in Korea (Jikseol). but was not practiced in Sejongsilrok. This was changed with time, and plowing for cultivation in Korea was interrelated with use of green manure crops, method of plowing of upseting plough, method of manure practice and sometimes dry plowing. In addition, until the 15th century method of using a kind of plowing-tool made of log as farm tools was created to support reclamation for enlargement of farm land in mountaineous and coastal areas. For desolate farm lands by many internal and external disturbances, one tried to recover yield ability by increasing labor productivity from the 17th or 18th century. To do this, ‘Banjongbeob’ (culture method by upset plowing weed control) and ‘Hwanubeob’(culture method by firing weed control) which were cultural methods of ancient China were readapoted but the results were not clearly informed. Also, the reality of those was reexamined in the end of the Chosun dynasty.

• Korean Journal of Environment and Ecology
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• v.38 no.3
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• pp.230-245
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• 2024

Amphibians, sensitive to external environmental changes, serve as bioindicator species for assessing alterations or disturbances in local ecosystems. It is known that one-third of amphibian species within the order Anura are at risk of extinction due to anthropogenic threats such as habitat destruction and fragmentation caused by urbanization. To develop effective protection and conservation strategies for anuran amphibians, species surveys that account for population characteristics are essential. This study aimed to investigate the potential for citizen participation in ecological monitoring using the mating calls of anura species. We also proposed suitable quality control measures to mitigate errors and biases, ensuring the extraction of reliable species occurrence data. The Citizen Science project was carried out nationwide from April 1 to August 31, 2022, targeting 12 species of anura amphibians in Korea. Citizens voluntarily participated in voice signal monitoring, where they listened to anura species' mating calls and recorded them using a mobile application. Additionally, we established a quality control process to extract reliable species occurrence data, categorizing errors and biases from citizen-collected data into three levels: omission, commission, and incorrect identification. A total of 6,808 observations were collected during the citizen participation in anura species vocalization monitoring. Through the quality control process, errors and biases were identified in 1,944 (28.55%) of the 6,808 data. The most common type of error was omission, accounting for 922 cases (47.43%), followed by incorrect identification with 540 cases (27.78%), and commission with 482 cases (24.79%). During the Citizen Science project, we successfully recorded the mating calls of 10 out of the 12 anuran amphibian species in Korea, excluding the Asian toads (Bufo gargarizans Cantor), Korean brown frog (Rana coreana). Difficulties in collecting mating calls were primarily attributed to challenges in observing due to population decline or discrepancies between the breeding season of non-emergent individuals and the timing of the citizen science project. This study represents the first investigation of distribution status and species emergence data collection through mating calls of anura species in Korea based on citizen participation. It can serve as a foundation for designing future bioacoustic monitoring that incorporates citizen science and quality control measures for citizen science data.