• Korean Journal of Mineralogy and Petrology
• /
• v.33 no.4
• /
• pp.307-324
• /
• 2020

Major and trace elements, and Sr, Nd, isotopic composition analysis have been carried out on the Miocene basalt (Huangsongpu basalt, 20 Ma) 25 km to northeast from the Mt. Baekdu. The basalt has Na2O+K2O=3.5~4.7 wt.%, and MgO=9.9~11.1 wt.%, containing Mg-rich olivine (Mg#=75~86), clinopyroxene (Mg#=72~85) and Ca-rich plagioclase micro-phenocrysts. These data suggest that the basalt belongs to the alkaline magma series with a primitive nature, crystallized at a near-liquidus. The basalt is also characterized by high Cr (394~479 ppm) and Ni (389~519 ppm) contents, Nb-Ta enrichment anomalies and OIB-like trace elements patterns, displaying identical signatures to those of typical intraplate magmas. The rare earth element (REE) patterns of the basalt and high (Gd/Yb)sample/(Gd/Yb)PM ratio (=2.8~3.5) suggest the parental magma was derived from relatively low-degree (3~5%) partial melting of garnet peridotite. The 143Nd/144Nd and 87Sr/86Sr composition of the basalt are higher than those of BSE. The high 87Sr/86Sr (= ~0.7058) ratio of the basalt indicates a contribution of recycled ancient oceanic crust or continental crust on the Pacific slab suggesting that the Huangsongpu basalt was generated from metasomatized mantle.

• Microbiology and Biotechnology Letters
• /
• v.48 no.4
• /
• pp.525-532
• /
• 2020

A continuous fermentation process was carried out to enhance hyaluronic acid (HA) production using Streptococcus zooepidemicus cells. During the 1st stage continuous operation from 8 h with a dilution rate of 0.029/h (D1), HA was produced in the range of 7.5-10 g/l. During the 2nd stage from 44 h with a dilution rate of 0.036/h (D2), HA production (8.28 g/l) was initially reduced to a small extent due to increase of dilution rate from D1 to D2, and then a new pseudo-steady state was formed within a few hours with a concurrent small variations of HA production. The HA amount produced during the latter part of the 2nd stage was stably maintained in the range of 8.28-9.48 g/l, about 4.7% less amount compared to the 1st stage. Due to 24% increase of dilution rate from D1 to D2, however, maximum volumetric productivity (DP) amounting to 0.341 g/l/h was obtained at 96 h during the 2nd stage. This maximum productivity obtained from the continuous culture turned out only a small increase (3%) as compared to the corresponding batch fermentation. However, it should be noted that, in the case of batch process, one run typically consists of serial stages of growth culture plus one final production culture. This implies that, if the continuous fermentation that practically needs no dead time necessary for the multi-stage growth cultures is run for longer period, the total amount of the accumulated HA would be far greater than the amount obtained from the corresponding batch culture performed for the identical period.

• Korean Journal of Heritage: History & Science
• /
• v.54 no.1
• /
• pp.164-183
• /
• 2021

This article examines how the production technology of the Chinese bronze mirror affected the Korean Peninsula and Japan. To that end, we looked at how the drawing of linked-arc designs in bronze mirrors was done. The drawing technique is classified into three methods: Type 1 and type 2 were confirmed to have been used in China, but type 3 was used not in China, but on the Korean Peninsula and in Japan. Type 1 and type 2 are basically the same, with an identical restored diameter of the linked-arc design, and type 2 is found elsewhere in the bronze mirror, and type 1 are not. Type 3 features different diameters, and the linked-arc design does not form a complete circle. This shows that the manufacturer of the bronze mirror did not use several bumpy compasses, but rather a single one with a fixed center and protrusion, rather than one that can be easily adjusted, as it is today. That is why, of course, a pair of compasses must have been used several times. In this regard, those who produced bronze mirrors on the Korean Peninsula in the early days understood not only the Chinese techniques of the linked-arc design, but also the meaning contained within them. On the other hand, the makers of bronze mirrors in Japan did not understand the patterns and simply imitated them. From the late Yayoi period, Japan understood and produced works with the principle of drawing the linked-arc design. As a representative example, bronze mirrors excavated from the tomb of Hirabaru can be referenced. Perhaps it can be assumed that, behind these works, there was a direct transfer of technology, such as the migration of the makers of bronze mirror makers like the Do family (陶氏), whose names were found written on bronze mirrors excavated from the Hirabaru tomb.

• Korean Journal of Optics and Photonics
• /
• v.33 no.4
• /
• pp.167-176
• /
• 2022

Adaptive optics (AO) systems compensate for atmospheric disturbance, especially phase distortion, by introducing counter-wavefront deformation calculated from real-time wavefront sensing or prediction. Because AO system implementations are time-consuming and costly, it is highly desirable to estimate the system's performance during the development of the AO system or its parts. Among several techniques, we mostly apply statistical analysis, computational simulation, and optical-bench tests. Statistical analysis estimates performance based on the sum of performance variances due to all design parameters, but ignores any correlation between them. Computational simulation models every part of an adaptive optics system, including atmospheric disturbance and a closed loop between wavefront sensor and deformable mirror, as close as possible to reality, but there are still some differences between simulation models and reality. The optical-bench test implements an almost identical AO system on an optical bench, to confirm the predictions of the previous methods. We are currently developing an AO system for a 1.6-m ground telescope using a deformable mirror that was recently developed in South Korea. This paper reports the results of the statistical analysis and computer simulation for the system's design and confirmation. For the analysis, we apply the Strehl ratio as the performance criterion, and the median seeing conditions at the Bohyun observatory in Korea. The statistical analysis predicts a Strehl ratio of 0.31. The simulation method similarly reports a slightly larger value of 0.32. During the study, the simulation method exhibits run-to-run variation due to the random nature of atmospheric disturbance, which converges when the simulation time is longer than 0.9 seconds, i.e., approximately 240 times the critical time constant of the applied atmospheric disturbance.

• Korean Journal of Heritage: History & Science
• /
• v.55 no.1
• /
• pp.51-61
• /
• 2022

Earthenware horn cups with horse head decorations were excavated from Tomb No. 7 of Bokcheon-dong, Dongraegu, Busan Metropolitan City. Made of earth in the shape of a horn, these cups are considered to have been used to drink alcohol or beverage. Large numbers of earthenware horn cups of various shapes were excavated from tombs located in the old territories of Silla and Gaya. A pair of earthenware horn cups were excavated from Tomb No. 7, and the two cups are almost identical in overall shapes and manufacturing techniques despite different sizes. Conservation treatment was carried out for the bigger one of the two horn cups this time. There are two cracks toward the horse head decorations around the mouth with missing parts observed. The chest of the horse touches the ground with one side decorating the horse head and the other side facing the conical mouth of the horn cup. It is in the U shape, striking a balance based on two legs attached behind. The surface of the horn cup was made with a potter's wheel, and the connection to the horse head has traces of cutting and trimming. The horse head is expressed realistically with its features including the ears, eyes, nose, and mouth well apprehended and its color is grey This study intended to investigate manufacturing techniques of the artifact by examining its internal structure through the condition survey in a non-destructive way. CT imaging was used to figure out its manufacturing techniques and to diagnose its condition, and accordingly the scientific conservation treatment was conducted to stabilize the artifact. The precise diagnosis on conservation condition found that there are two chips in the spout with their cracks extended. One of the chips is connected with separation added to the crack. The material which has been used for connection in the past was collected for the infrared spectroscopic analysis, which was identified to be nitrocellulose resin for the connection. Therefore, this conservation treatment focused on removing the old material and preventing the spread of cracks. Before conservation treatment, the condition survey and scientific examination for the artifact were carried out to secure data about the earthenware horn cup with horse head decorations(Treasure). Based on them, effective plans for its conservation treatment was sought for and then existing adhesive was safely removed, and restoration material was selected to take into account its reversibility. In addition, the conservation treatment according to optimal methodologies was conducted through the consultation meeting with experts.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.34 no.2
• /
• pp.37-45
• /
• 2022

A simplified model using the lifetime distribution has been presented to estimate the Mean Residual Life (MRL) of rubble-mound breakwaters, which is not like a stochastic process model based on time-dependent history data to the cumulative damage progress of rubble-mound breakwaters. The parameters involved in the lifetime distribution can be easily estimated by using the upper and lower limits of lifetime and their likelihood that made a judgement by several experts taking account of the initial design lifetime, the past sequences of loads, and others. The simplified model presented in this paper has been applied to the rubble-mound breakwater with TTP armor layer. Wiener Process (WP)-based stochastic model also has been applied together with Monte-Carlo Simulation (MCS) technique to the breakwater of the same condition having time-dependent cumulative damage to TTP armor layer. From the comparison of lifetime distribution obtained from each models including Mean Time To Failure (MTTF), it has found that the lifetime distributions of rubble-mound breakwater can be very satisfactorily fitted by log-normal distribution for all types of cumulative damage progresses, such as exponential, linear, and logarithmic deterioration which are feasible in the real situations. Finally, the MRL of rubble-mound breakwaters estimated by the simplified model presented in this paper have been compared with those by WP stochastic process. It can be shown that results of the presented simplified model have been identical with those of WP stochastic process until any ages in the range of MTT F regardless of the deterioration types. However, a little of differences have been seen at the ages in the neighborhood of MTTF, specially, for the linear and logarithmic deterioration of cumulative damages. For the accurate estimation of MRL of harbor structures, it may be desirable that the stochastic processes should be used to consider properly time-dependent uncertainties of damage deterioration. Nevertheless, the simplified model presented in this paper can be useful in the building of the MRL-based preventive maintenance planning for several kinds of harbor structures, because of which is not needed time-dependent history data about the damage deterioration of structures as mentioned above.

• Journal of the Daesoon Academy of Sciences
• /
• v.38
• /
• pp.183-208
• /
• 2021

In order to examine the origin of Image-Number Theory in Cho Hoik (曺好益)'s Yixiangshuo (易象說), it is necessary to review Hu Yigui (胡一桂)'s Zhouyi Benyi Fulu Zuanzhu (周易本義附録纂注). Hu Yigui based his work on Zhu Xi's Zhouyi Benyi, he took related contents such as the Zhu Xi's writings and phrases and organized them into a fulu (附録), and he collected commentaries that matched the meaning of Zhouyi Benyi among the theories of many Confucian scholars and produced a zuanzhu (纂注). In addition to these, there are 'Yuwei (愚謂)' and 'Yuan (愚案)' which allowed him to add his own opinion. The system of Hu Yigui's Zhouyi Benyi Fulu Zuanzhu almost coincides with Cho Hoik's Yi-ological writing system. In other words, Cho Hoik appears to have written Yizhuan Bianjie (易傳辨解) and Zhouyi Shijie (周易釋解) as a fulu and zuanzhu of Zhouyi Benyi Fulu Zuanzhu. And there is Yixiangshuo which corresponds to 'Yuwei' and 'Yuan' of Zhouyi Benyi Fulu Zuanzhu. Yixiangshuo was not originally an independent Yi-ological book, but was compiled by later generations from what was recorded in the form of the head notes of Zhouyi (周易). Thus, Yixiangshuo takes almost the same form as the 'Yuwei' and 'Yuan' of Zhouyi Benyi Fulu Zuanzhu. In addition, Cho Hoik's Yixiangshuo cites many contents from 'Yuwei' and 'Yuan' of Zhouyi Benyi Fulu Zuanzhu. On the other hand, in order to examine the origin of Image-Number Theory in Cho Hoik's Yixiangshuo, the Yi-ology of Zhu Zhen (朱震) cannot be overlooked. This is true not only due to the fact that Yixiangshuo is quoting Zhu Zhen. The more significant reason is Yixiangshuo is a fundamental aspect of Zhu Zhen's Yi-ology. As demonstrated in the main body of this article, the methodology of Image-Number Theory in Yixiangshuo and its counterpart in Hanshang Yizhuan (漢上易傳) are almost identical. In conclusion, the origin of Image-Number Theory in Cho Hoik's Yixiangshuo can be found in both the Hu Yigui's Zhouyi Benyi Fulu Zuanzhu and Zhu Zhen's Hanshang Yizhuan. In particular, it can be said that its origin can be found in both the 'Yuwei' and 'Yuan' of Zhouyi Benyi Fulu Zuanzhu and the methodlogy of Image-Number Theory in Hanshang Yizhuan.

• Korean Journal of Remote Sensing
• /
• v.38 no.6_1
• /
• pp.1505-1514
• /
• 2022

Image matching is a crucial preprocessing step for effective utilization of multi-temporal and multi-sensor very high resolution (VHR) satellite images. Deep learning (DL) method which is attracting widespread interest has proven to be an efficient approach to measure the similarity between image pairs in quick and accurate manner by extracting complex and detailed features from satellite images. However, Image matching of VHR satellite images remains challenging due to limitations of DL models in which the results are depending on the quantity and quality of training dataset, as well as the difficulty of creating training dataset with VHR satellite images. Therefore, this study examines the feasibility of DL-based method in matching pair extraction which is the most time-consuming process during image registration. This paper also aims to analyze factors that affect the accuracy based on the configuration of training dataset, when developing training dataset from existing multi-sensor VHR image database with bias for DL-based image matching. For this purpose, the generated training dataset were composed of correct matching pairs and incorrect matching pairs by assigning true and false labels to image pairs extracted using a grid-based Scale Invariant Feature Transform (SIFT) algorithm for a total of 12 multi-temporal and multi-sensor VHR images. The Siamese convolutional neural network (SCNN), proposed for matching pair extraction on constructed training dataset, proceeds with model learning and measures similarities by passing two images in parallel to the two identical convolutional neural network structures. The results from this study confirm that data acquired from VHR satellite image database can be used as DL training dataset and indicate the potential to improve efficiency of the matching process by appropriate configuration of multi-sensor images. DL-based image matching techniques using multi-sensor VHR satellite images are expected to replace existing manual-based feature extraction methods based on its stable performance, thus further develop into an integrated DL-based image registration framework.

• Journal of Life Science
• /
• v.31 no.12
• /
• pp.1088-1093
• /
• 2021

Jeju horse (Equus ferus caballus) is a Korean horse breed that has been native to Jeju Island for a long time. Jeju horses are used as racehorses, and their racing ability is a major economic trait. The role of the myostatin (MSTN) gene in skeletal muscle mass has been studied in various mammals, and mutations in the MSTN gene are known to affect the racing ability and stamina of thoroughbreds. In this study, we compared the frequency of mutations in the MSTN gene in several horse breeds, including 1,433 Jeju horses. Among the mutations (ECA18 g.66493737C>T) in the MSTN gene, the long-distance aptitude genotype (TT) was found to have a frequency of 0.826 in Jeju horses, which was higher than that in Halla horses (0.285) and thoroughbreds (0.252). The genotypes and arrival records of Jeju horses were compared according to various distances (400 m, 800 m, 900 m, 1,000 m, 1,110 m, and 1,200 m). According to the results, the CT type showed a faster-reaching record than the TT type in races of less than 1,000 m. However, almost identical results were confirmed in races over 1,110 m. This study suggests that the MSTN mutation in Jeju horses may be related to race distance aptitude. In future research, the data in this study can be used for developing markers related to race distance aptitude and racing abilities in Jeju horses.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.24 no.4
• /
• pp.330-336
• /
• 2022

It is likely that the heading would occur early when air temperature increases. In 2022, however, the heading date was delayed unusually, e.g., by 3 to 5 days although temperature during the vegetative growth stage was higher than normal years. The objective of this study was to identify the cause of such event analyzing weather variables including average temperature, sunshine hours, and day-length for each growth stage. The observation data were collected for medium-late maturing varieties, which has been grown at crop yield experiment sites including Daegu, Andong, and Yesan. The difference in heading date was compared between growing seasons in 2021 and 2022 because crop management options, e.g., the cultivars and cultivation methods, were identical at those sites during the study period. It appeared that the heading date was delayed due to the difference in temperature responsiveness under a given day-length condition The effect of the temperature increase on the heading date differed between the periods during which when the day-length was more than 14.3 hours before and after the summer-solstice.. The effect of the temperature decrease during the period from which the day-length decreased to less than 14.3 hours to the heading date was relatively greater. This merits further studies to examine the response of rice to the temperature change under different day-length and sunshine duration in terms of heading.