• Korean Journal of Acupuncture
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• v.32 no.3
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• pp.136-143
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• 2015

This study was performed to comparative investigate the distribution of primary sensory and motor neurons associated with Cheonji(PC1) acupoint by using neural tracing technique. A total 4 SD rats were used in the present study. After anesthesia, the rats received microinjection of $6{\mu}l$ of cholera toxin B subunit(CTB) into the corresponding sites of the acupoints Cheonji(PC1) in the human body for observing the distribution of the related primary sensory neurons in dorsal root ganglia(DRGs) and motor neurons in the spinal cord(C3~T4) and sympathetic ganglia. Three days after the microinjection, the rats were anesthetized and transcardially perfused saline and 4% paraformaldehyde, followed by routine section of the DRGs, sympathetic chain ganglia(SCGs) and spinal cord. Labeled neurons and nerve fibers were detected by immunohistochemical method and observed by light microscope equipped with a digital camera. The labeled neurons were recorded and counted. From this research, the distribution of primary sensory and motor neurons associated with Cheonji(PC1) acupoints were concluded as follows. Muscle meridian related Cheonji(PC1) are controlled by spinal segments of C5~T1, C6~T4, respectively.

• The Journal of Engineering Geology
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• v.23 no.4
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• pp.409-425
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• 2013

This study presents a prediction of a time-series of the area inundated by effluent from Heavenly Lake caused by ground behavior prior to a volcanic eruption. A GIS-based hydrological algorithm that considers the multi-flow direction of effluent, the absorption and storage capacity of the ground soil, the storage volume of the basin or the depression terrain, was developed. To analyze the propagation pattern, four hypothetical collapse zones on the cheonji ground were set, considering the topographical characteristics and distributions of volcanic rocks at Mt. Baekdu. The results indicate that at 3 hours after collapse, for both scenarios 1 and 2 (collapses of the entire/southern boundary of cheonji), a flood hazard exists for villages in China, but not for those on the North Korean side of the mountain, due to the topographical characteristics of Mt. Baekdu. It is predicted that villages in both North Korea and China would be significantly damaged by flood inundation at 3 hours elapsed time for both scenarios 3 and 4 (collapses on the southern boundary of cheonji and on the southeastern-peak area).

• Korean Journal of Remote Sensing
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• v.38 no.6_2
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• pp.1691-1707
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• 2022

Cheonji Lake, the caldera of Baekdu Mountain, located on the border of the Korean Peninsula and China, alternates between melting and freezing seasonally. There is a magma chamber beneath Cheonji, and variations in the magma chamber cause volcanic antecedents such as changes in the temperature and water pressure of hot spring water. Consequently, there is an abnormal region in Cheonji where ice melts quicker than in other areas, freezes late even during the freezing period, and has a high-temperature water surface. The abnormal area is a discharge region for hot spring water, and its ice gradient may be used to monitor volcanic activity. However, due to geographical, political and spatial issues, periodic observation of abnormal regions of Cheonji is limited. In this study, the degree of ice change in the optimal region was quantified using a Landsat -5/-7/-8 optical satellite image and a Modified U-Net regression model. From January 22, 1985 to December 8, 2020, the Visible and Near Infrared (VNIR) band of 83 Landsat images including anomalous regions was utilized. Using the relative spectral reflectance of water and ice in the VNIR band, unique data were generated for quantitative ice variability monitoring. To preserve as much information as possible from the visible and near-infrared bands, ice gradient was noticed by applying it to U-Net with two encoders, achieving good prediction accuracy with a Root Mean Square Error (RMSE) of 140 and a correlation value of 0.9968. Since the ice change value can be seen with high precision from Landsat images using Modified U-Net in the future may be utilized as one of the methods to monitor Baekdu Mountain's volcanic activity, and a more specific volcano monitoring system can be built.

• Journal of the Korean earth science society
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• v.34 no.6
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• pp.479-491
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• 2013

Products of the eruption of Mt. Baekdusan are identified as volcanic materials at the estuaries of the Songhuagang river to north, the Dumangang river to east and the Amnokgang river to west. More speficially, pyroclastic flows, lahars and volcanic floods can affect an area of 400km in radius, centering around Lake Cheonji caldera. However, unlike the millenium eruption, the flow situation has been changed. Because multi-purpose dams and reserviors with a combined pondage of mora than 2 billion tons of water have been built in the rivers of which sources are originated from Lake Cheonji caldera. In addition, the flow of fluids expected to take place when the volcano has erupted is thought to be affected by artificial constructions in both direct and indirect ways. This study calculates the direction of fluids flow by using numerical analyses of pyroclastic flows, lahars and volcanic floods that can occur when the volcano of Mt. Baekdusan has erupted. We also estimate the scope of damages by pyroclastic flows, lahars, volcanic flooding caused by the pondage of the dams and water storages in and around Mt. Baekdusan. Pyroclastic flows transported over the steep slopes at the early times of eruptions move over the mountain slopes, affecting airplanes, and lahars due to leaks of Lake Cheonji could reach as far as major rivers and streams near Mt. Baekdusan. Unlike historical accounts, volcanic flood is expected to be limited in its scope of influence to reservoirs bigger than Lake Cheonji in pondage.

• Journal of the Korean earth science society
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• v.41 no.1
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• pp.31-39
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• 2020

Cheonji, the largest caldera lake in Asia, is located at the summit of Baekdu Mountain. Cheonji is covered with snow and ice for about six months of the year due to its high altitude and its surrounding environment. Since most of the sources of water are from groundwater, the water temperature is closely related to the volcanic activity. However, in the 2000s, many volcanic activities have been monitored on the mountain. In this study, we analyzed the dimension of ice produced during winter in Baekdu Mountain using Sentinel-1 satellite image data provided by the European Space Agency (ESA). In order to calculate the dimension of ice from the backscatter image of the Sentinel-1 satellite, 20 Gray-Level Co-occurrence Matrix (GLCM) layers were generated from two polarization images using texture analysis. The method used in calculating the area was utilized with the Support Vector Machine (SVM) algorithm to classify the GLCM layer which is to calculate the dimension of ice in the image. Also, the calculated area was correlated with temperature data obtained from Samjiyeon weather station. This study could be used as a basis for suggesting an alternative to the new method of calculating the area of ice before using a long-term time series analysis on a full scale.

• Journal of the Daesoon Academy of Sciences
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• v.30
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• pp.163-199
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• 2018

Jeon-gyeong was published under the command of Dojeon Park Wudang in 1974. The scripture consists of 7 parts and each part has 17 chapters. The earliest record of Gucheon Sangje (1871~1909) can be found in Jeungsan Cheonsa Gongsagi, which was published by Lee Sangho (1888~1967) in 1926. The book was the first oral literature that he created by collecting information and materials on Jeungsan as he personally met with many direct disciples of Gucheon Sangje. In 1929, after three years, Lee complemented the book with additional materials and published the first edition of Daesoon Jeon-gyeong. It was a form of didactic literature stylistically presented as scripture. Lee continued this long journey of work by revising and publishing 6 editions of Daesoon Jeon-gyeong until he published the last one in 1965. The chapter titled, "Cheonji-gongsa (Reordering Works of the Universe)" from Daesoon Jeon-gyeong as the sixth chapter out of a total of 13 chapters in the first edition, but in the last edition, it appears as chapter 4 out of a total of 9 chapters. Here it is shown that the last edition has been shortened when compared to the first edition. Also the number of verses in the chapter has largely increased by almost twice its original size over the 37 years; as it was 81 in the first edition, 94 in the second, 148 in the third, 151 in the fifth, and 175 in the sixth. In this paper, I studied how the verses of "Gongsa (Reordering Works)" from the Jeon-gyeong, which was first published in 1974, have been revised in comparison to the chapter titled "Cheonji-gongsa" from the Daesoon Jeon-gyeong. As the result of comparing each verse of "Gongsa" from the Jeon-gyeong to those of "Cheonji-gongsa" from all six editions of the Daesoon Jeon-gyeong, I could find the following revisions or changes. First, when "Cheonji-gongsa" from the Daesoon Jeon-gyeong is compared to "Gongsa" from the Jeon-gyeong, it can be seen that the number of verses has been changed and some contents have been deleted or added. Second, the sixth edition of the Daesoon Jeon-gyeong has 69 more verses than the Jeon-gyeong, and most of the additions were made in the chapters titled "Haengrok (analects)," "Gyoun (conveyance of teachings)," and "Yesi (forseeing)". These additions show how the verses regarding religious and predictional teachings developed over the years. Third, the verses from "Gongsa" from the Jeon-gyeong contain many descriptions from chapter 2, "Enlightenment of Dao and Miraculous Deeds of Cheonsa (Heavenly Teacher)," chapter 3, "Followers in the Dao School and Precepts," and chapter 5, "Opening of New World and Paradise," from the 6 th edition of the Daesoon Jeon-gyeong. This indicates that "Cheonji-gongsa (Reordering Works of the Universe)" was related to miraculous acts, enlightenment to Dao, teachings given to the followers, the opening of new world, and the building of a paradise. Fourth, some chapters in the section "Cheonji-gongsa" from Daesoon Jeon-gyeong are omitted in "Gongsa" from Jeon-gyeong, and "Gongsa" has some new contents that were not included in previous texts. This shows that there had been adoptions of different materials in the process of transmission.

• Journal of the Korean earth science society
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• v.34 no.6
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• pp.492-506
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• 2013

The historical accounts and materials about the eruption of Mt. Baekdusan as observed by the geological survey is now showing some signs of waking from a long slumber. As a response of the volcanic eruption of Mt. Baekdusan, water release may occur from the stored water in Lake Cheonjii caldera. The volcanic flood is crucial in that it has huge potential energy that can destruct all kinds of man-made structures and that its velocity can reach up to 100 km $hr^{-1}$ to cover hundreds of kilometers of downstream of Lake Cheonji. The ultimate goal of the study is to estimate the level of damage caused by the volcanic flood of Lake Cheon-Ji caldera. As a preliminary study a scenario-based numerical analysis is performed to build hydrographs as a function of time. The analysis is performed for each scenario (breach, magma uplift, combination of uplift and breach, formation of precipitation etc.) and the parameters to require a model structure is chosen on the basis of the historic records of other volcanos. This study only considers the amount of water at the rim site as a function of time for the estimation whereas the downstream routing process is not considered in this study.

• The Journal of the Petrological Society of Korea
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• v.24 no.4
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• pp.337-345
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• 2015

Pumices from the summit area of the Mt. Baekdu was analysed with respect to the physical characteristics. Fallout pumice deposits around the somma of the Cheonji caldera, Mt. Baekdu consist mainly of white pumices, but black pumices and gray pumices are also displayed together. White pumices are mainly rhyolitic($SiO_2$ 71.1%) and black pumices are trachytic($SiO_2$ 64.8%) in composition, and gray pumices are intermediate composition($SiO_2$ 68.0%) between white pumices and black pumices. Average density of felsic magma formed the Mt. Baekdu pumices is $2.45g/cm^3$ in anhydrous magma and $2.33g/cm^3$ in hydrous magma, respectively. We determined the density and calculated the vesicularity of three different coloured pumices, which collected in the vicinity of the Waho-bong(2,566 m) and Gwanmyeonbong(2,526 m) of southern somma of the Cheonji caldera, Mt. Baekdu. Average density of the yellow pumices was measured as $0.74g/cm^3$, black pumices as $0.75g/cm^3$, and gray t0 white pumices as $0.73g/cm^3$. Average density regardless of the colour of pumices was nearly constant at $0.75g/cm^3$. Vesicularity of pumices is calculated to be 67.8~69.4% and these pumices can be classified as a highly vesicular according to classification of vesiculation characteristics.

• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.575-581
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• 2018

The relationship between the body size of species and the environment has been an active research subject for many years. Until recently, studies had focused on the relationship between the body size and environment based on the ecogeographic rule for various animal groups. In this study, we examined the relationship between body size of Hyla japonica and the habitat environment in Jeju island located at the southernmost part of the Korean peninsula. We collected H. japonica from three breeding sites, Cheonji, Bonggae, and Aewol, and measured SVL, BW, and HW of the species. We also measured the altitude, longitude, latitude, annual mean temperature, and annual mean precipitation of each site to analyze the relationship between the body size and the habitat environment. The analysis results showed that there was the clear difference of the body size according to the habitat and the body size in Aewol was significantly bigger than others, while the body size in Cheonji was the smallest. The altitude was the most important environmental variable and showed a positive correlation with body size. The body size of H. japonica increased as the altitude increased, and this results were consistent with Bergmann's rule, one of the biological laws related to body size. In conclusion, the environment could affect the body size of H. japonica, and the body size has a certain direction according to the environment.

• Journal of the Korean earth science society
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• v.34 no.6
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• pp.456-469
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• 2013

This study is performed to find out the eruptive events of the historical period recorded in literature, which have been recognized and regarded as ones from Mt. Baekdusan, and to make volcanological interpretations of the eruptive events. Since the Millennium eruption, more than 31 eruptive events have been discovered, most of which are Plinian eruptions with volcanic ash that dispersed into the regions in the vicinity of the volcano. The 1903 record includes the event of the phreatomagmatic or vulcanian eruption that occurred within the Cheonji caldera lake. Based on the eruption records of the historical period and the 2002 precursor unrest to volcanic eruptions, Mt. Baekdusan has been evaluated and regarded as an active volcano that has the potential to erupt in the future.