• Tunnel and Underground Space
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• v.34 no.2
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• pp.89-103
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• 2024

In the disposal environment, gases can be generated at the interface between canister and buffer due to various factors such as anaerobic corrosion, radiolysis, and microbial degradation. If the gas generation rate exceeds the diffusion rate, the gas within the buffer may compress, resulting in physical damage to the buffer due to the increased pore pressure. In particular, the rapid movement of gases, known as gas breakthroughs, through the dilatancy pathway formed during this process may lead to releasing radionuclide. Therefore, understanding these gas generation and movement mechanism is essential for the safety assessment of the disposal systems. In this study, an experimental apparatus for investigating gas migration within buffer was constructed based on a literature review. Subsequently, a gas injection experiment was conducted on a compacted bentonite block made of Bentonile WRK (Clariant Ltd.) powder. The results clearly demonstrated a sharp increase in stress and pressure typically observed at the onset of gas breakthrough within the buffer. Additionally, the range of stresses induced by the swelling phenomenon of the buffer, was 4.7 to 9.1 MPa. The apparent gas entry pressure was determined to be approximately 7.8 MPa. The equipment established in this study is expected to be utilized for various experiments aimed at building a database on the initial properties of buffer and the conditions during gas injection, contributing to understanding the gas migration phenomena.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.14
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• pp.165-172
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• 1973

The sterile phenomenon is frequently found in the inter-species hybrids of ginseng as in other plants. It is known that among the hybrids between Panax Ginseng (PG) and Panax Quinquefolium (PQ), and between Panax Ginseng and Paxax Japonicus (PI), PG${\times}$PI is fertile only very rarely, while PG ${\times}$ PQ is always sterile. Therefore, in order to clarify the relationship between this sterility phenomenon and the metabolism of free amino acids, the changes of free amino acids through the formation of the flower organs and seeds of two hybrids, PG ${\times}$ PQ and PG ${\times}$ PI were investigated by thin layer chromatography. The results are summarized as follows: 1. Distinct differences in the quantity and number of free amino acids were recognized between PG ${\times}$ PQ, PG ${\times}$ PI and their parent plants. From the hybrid PG ${\times}$ PQ, 19 kinds of ninhyrin sensitive substances were detected in all. They were (1) 17 amino acids: alanine, valine, leucine, phenylalanine, proline, hydroxy-proline, serine, threonine, tyrosine, aspartic acid, glutamic acid, lysine, arginine, ${\gamma}$-amino butyric acid, ${\beta}$-alanine, cysteic acid and tryptophan, and (2) two amides: asparagine and glutamine. From the hybrid PG ${\times}$ PI, in addition to the above 19 substances, methionine and one unknown substance were detected. 2. Generally, alanine, as partie acid, glutamic acid, cysteic acid and asparagine were detected in large amounts in the two hybrids as in PG, PG and PJ but it was a noticeable fact concerning these two hybrids that the largest quantity of asparagine was found at microspore satge and pollen mature stage. 3. The decrease of cysteic acid in the two hybrids at the red ripened stage was the same as in PQ and PJ but opposite to the change in PG. The detection of methionine in PG ${\times}$ PJ was worthy of notice. 4. The change of proline was conspicuously different from that in their parent plants. It was detected as a trace of color at the micros pore stage while asparagine was detected in the greatest amount at that time. It is well known that the quantity of proline is closely related to the sterility of plant. This fact was also found true in the formation of ginseng seeds. It was reported as well that asparagine accumulated when proline decreased. 5. The deficiency of proline seemed to be closely related with the sterility of hybrids and with the degradation of pollen in anther. 6. The difference in the changes of free amino acids between the selfed lines of PG, PQ and PJ, and their hybrids seemed to be caused by the transformation of gene-action system by hybridization. On these phenomena along with proline metabolim and its physiological role in seed formation further studies are required.

• Korean Journal of Remote Sensing
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• v.39 no.3
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• pp.297-309
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• 2023

The degradation of coastal ecosystems and fishery environments is accelerating due to the recent phenomenon of invertebrate grazers. To effectively monitor and implement preventive measures for this phenomenon, the adoption of remote sensing-based monitoring technology for extensive maritime areas is imperative. In this study, we compared and analyzed the robustness of deep learning-based object detection modelsfor detecting and monitoring invertebrate grazersfrom underwater videos. We constructed an image dataset targeting seven representative species of invertebrate grazers in the coastal waters of South Korea and trained deep learning-based object detection models, You Only Look Once (YOLO)v7 and YOLOv8, using this dataset. We evaluated the detection performance and speed of a total of six YOLO models (YOLOv7, YOLOv7x, YOLOv8s, YOLOv8m, YOLOv8l, YOLOv8x) and conducted robustness evaluations considering various image distortions that may occur during underwater filming. The evaluation results showed that the YOLOv8 models demonstrated higher detection speed (approximately 71 to 141 FPS [frame per second]) compared to the number of parameters. In terms of detection performance, the YOLOv8 models (mean average precision [mAP] 0.848 to 0.882) exhibited better performance than the YOLOv7 models (mAP 0.847 to 0.850). Regarding model robustness, it was observed that the YOLOv7 models were more robust to shape distortions, while the YOLOv8 models were relatively more robust to color distortions. Therefore, considering that shape distortions occur less frequently in underwater video recordings while color distortions are more frequent in coastal areas, it can be concluded that utilizing YOLOv8 models is a valid choice for invertebrate grazer detection and monitoring in coastal waters.

• Journal of Intelligence and Information Systems
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• v.24 no.2
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• pp.243-264
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• 2018

Although the worldwide battery market is recently spurring the development of lithium secondary battery, lead acid batteries (rechargeable batteries) which have good-performance and can be reused are consumed in a wide range of industry fields. However, lead-acid batteries have a serious problem in that deterioration of a battery makes progress quickly in the presence of that degradation of only one cell among several cells which is packed in a battery begins. To overcome this problem, previous researches have attempted to identify the mechanism of deterioration of a battery in many ways. However, most of previous researches have used data obtained in a laboratory to analyze the mechanism of deterioration of a battery but not used data obtained in a real world. The usage of real data can increase the feasibility and the applicability of the findings of a research. Therefore, this study aims to develop a model which predicts the battery deterioration using data obtained in real world. To this end, we collected data which presents change of battery state by attaching sensors enabling to monitor the battery condition in real time to dozens of golf carts operated in the real golf field. As a result, total 16,883 samples were obtained. And then, we developed a model which predicts a precursor phenomenon representing deterioration of a battery by analyzing the data collected from the sensors using machine learning techniques. As initial independent variables, we used 1) inbound time of a cart, 2) outbound time of a cart, 3) duration(from outbound time to charge time), 4) charge amount, 5) used amount, 6) charge efficiency, 7) lowest temperature of battery cell 1 to 6, 8) lowest voltage of battery cell 1 to 6, 9) highest voltage of battery cell 1 to 6, 10) voltage of battery cell 1 to 6 at the beginning of operation, 11) voltage of battery cell 1 to 6 at the end of charge, 12) used amount of battery cell 1 to 6 during operation, 13) used amount of battery during operation(Max-Min), 14) duration of battery use, and 15) highest current during operation. Since the values of the independent variables, lowest temperature of battery cell 1 to 6, lowest voltage of battery cell 1 to 6, highest voltage of battery cell 1 to 6, voltage of battery cell 1 to 6 at the beginning of operation, voltage of battery cell 1 to 6 at the end of charge, and used amount of battery cell 1 to 6 during operation are similar to that of each battery cell, we conducted principal component analysis using verimax orthogonal rotation in order to mitigate the multiple collinearity problem. According to the results, we made new variables by averaging the values of independent variables clustered together, and used them as final independent variables instead of origin variables, thereby reducing the dimension. We used decision tree, logistic regression, Bayesian network as algorithms for building prediction models. And also, we built prediction models using the bagging of each of them, the boosting of each of them, and RandomForest. Experimental results show that the prediction model using the bagging of decision tree yields the best accuracy of 89.3923%. This study has some limitations in that the additional variables which affect the deterioration of battery such as weather (temperature, humidity) and driving habits, did not considered, therefore, we would like to consider the them in the future research. However, the battery deterioration prediction model proposed in the present study is expected to enable effective and efficient management of battery used in the real filed by dramatically and to reduce the cost caused by not detecting battery deterioration accordingly.

• Journal of the Korean association of regional geographers
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• v.23 no.1
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• pp.106-117
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• 2017

Recently, urban regeneration is being actively promoted in Korea and among those Jeonju Hanok Village is the major project which is the most consistently promoted. For this, visitors of Jeonju Hanok Village are skyrocketing. However, due to this condition, various problems are occurring, especially about commercialization. In this regard, this study is to suggest management of the Jeonju Hanok Village and new orientation in the policy, by analyzing physical, economic, and social status due to urban regeneration for Jeonju Hanok Village which has lost its identity and been commercialized. For this, the study analyzed changes in land usage and real transaction price, SNS data. Firstly, in the physical analysis, the study realized that there is commercialization going around the main streets of Jeonju Hanok Village. Due to the rapid commercialization, living spaces for locals are replaced to commercial spaces for tourists, and the emigration of locals is caused by economic/environmental damages with the degradation of housing environments. Secondly, in the economic analysis, there was no gap in real transactions among streets in 2010 but has shown a valid gap in 2016. The traffic of tourists is heavy and the real transaction prices of streets that are adjacent to major tourist sights rose the most. Rising real transaction prices are a positive phenomenon in the aspect of the city regeneration but it is concerned that they can be perceived as investment subjects. Thirdly, in the social analysis, tourists are using commercial aspects more than historical or cultural sites, and have lots of interest on those. However, because there are also lots of opinions about the commercialization of Hanok Village, we think the plans which can establish the identity of Hanok Village should be prepared. The study has its meaning on analyzing reality based on the land usage, real transaction, SNS data and suggesting political implications.