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Sequential Use of COMSOL Multiphysics® and PyLith for Poroelastic Modeling of Fluid Injection and Induced Earthquakes (COMSOL Multiphysics®와 PyLith의 순차 적용을 통한 지중 유체 주입과 유발지진 공탄성 수치 모사 기법 연구)

  • Jang, Chan-Hee;Kim, Hyun Na;So, Byung-Dal
    • The Journal of Engineering Geology
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    • v.32 no.4
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    • pp.643-659
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    • 2022
  • Geologic sequestration technologies such as CCS (carbon capture and storage), EGS (enhanced geothermal systems), and EOR (enhanced oil recovery) have been widely implemented in recent years, prompting evaluation of the mechanical stability of storage sites. As fluid injection can stimulate mechanical instability in storage layers by perturbing the stress state and pore pressure, poroelastic models considering various injection scenarios are required. In this study, we calculate the pore pressure, stress distribution, and vertical displacement along a surface using commercial finite element software (COMSOL); fault slips are subsequently simulated using PyLith, an open-source finite element software. The displacement fields, are obtained from PyLith is transferred back to COMSOL to determine changes in coseismic stresses and surface displacements. Our sequential use of COMSOL-PyLith-COMSOL for poroelastic modeling of fluid-injection and induced-earthquakes reveals large variations of pore pressure, vertical displacement, and Coulomb failure stress change during injection periods. On the other hand, the residual stress diffuses into the remote field after injection stops. This flow pattern suggests the necessity of numerical modeling and long-term monitoring, even after injection has stopped. We found that the time at which the Coulomb failure stress reaches the critical point greatly varies with the hydraulic and poroelastic properties (e.g., permeability and Biot-Willis coefficient) of the fault and injection layer. We suggest that an understanding of the detailed physical properties of the surrounding layer is important in selecting the injection site. Our numerical results showing the surface displacement and deviatoric stress distribution with different amounts of fault slip highlight the need to test more variable fault slip scenarios.

Improvements in Patch-Based Machine Learning for Analyzing Three-Dimensional Seismic Sequence Data (3차원 탄성파자료의 층서구분을 위한 패치기반 기계학습 방법의 개선)

  • Lee, Donguk;Moon, Hye-Jin;Kim, Chung-Ho;Moon, Seonghoon;Lee, Su Hwan;Jou, Hyeong-Tae
    • Geophysics and Geophysical Exploration
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    • v.25 no.2
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    • pp.59-70
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    • 2022
  • Recent studies demonstrate that machine learning has expanded in the field of seismic interpretation. Many convolutional neural networks have been developed for seismic sequence identification, which is important for seismic interpretation. However, expense and time limitations indicate that there is insufficient data available to provide a sufficient dataset to train supervised machine learning programs to identify seismic sequences. In this study, patch division and data augmentation are applied to mitigate this lack of data. Furthermore, to obtain spatial information that could be lost during patch division, an artificial channel is added to the original data to indicate depth. Seismic sequence identification is performed using a U-Net network and the Netherlands F3 block dataset from the dGB Open Seismic Repository, which offers datasets for machine learning, and the predicted results are evaluated. The results show that patch-based U-Net seismic sequence identification is improved by data augmentation and the addition of an artificial channel.

Floristic Study of Namhansanseong (Gwangju-si, Gyeonggi-do) in Korea (남한산성(경기도 광주시)의 관속식물상)

  • Kwon, Seog Woo;Kim, Jung-Hyun;Kim, Tae-Sung;Park, Sung-Ae;Yoon, Chang-Young
    • Korean Journal of Plant Resources
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    • v.35 no.4
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    • pp.541-563
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    • 2022
  • This study aimed to elucidate the distribution of vascular plants in Namhansanseong (Gwangju-si, Gyeonggi-do), Korea. The results of 30 field surveys from June 2019 to June 2020 identified 568 total taxa, representing 513 species, 10 subspecies, 40 varieties, 3 forms, and 2 hybrids in 335 genera and 107 families. Among them, 17 taxa were endemic plants to Korea, and one taxon were endangered plant and three taxa were red list plants. The floristic target plants amounted to 63 taxa, specifically one taxon of grade V, seven taxa of grade IV, 12 taxa of grade III, 14 taxa of grade II, and 29 taxa of grade I. And 66 taxa were northern lineage plants. Alien plants were recorded a total of 61 taxa with a Naturalized Index of 10.7%, the Urbanization Index was calculated to be 9.8%. As the result of comparison with previous studies, in this study a total of 213 taxa were newly identified representing 187 species, three subspecies, 19 varieties, one form, and two hybrids in 161 genera and 66 families.

A Study on Awareness and Experience of Data Publishing by Scientists (과학기술분야 연구자들의 데이터 출판경험 및 인식 연구)

  • Hyekyong Hwang;Youngim Jung;Sung-Nam Cho;Tae-Sul Seo;Jihyun Kim
    • Journal of Korean Library and Information Science Society
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    • v.54 no.1
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    • pp.45-68
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    • 2023
  • This study aims to investigate the awareness and experiences of domestic researchers regarding data publishing, which has been recognized as a new channel of data sharing as scholarly communication evolves in the open science environment. A survey is conducted among researchers from five government-funded research institutes in the field of science and technology and members of the GeoAI Data Society to confirm the awareness of data publishing. As a result of the study, domestic researchers recognized providing explanations for data, stable access to data, citation, and quality assurance through peer review as the advantages of data journals. On the contrary, a low level of recognition for data paper as one of the research outputs was presented. With regard to the properties of data publication, the respondents answered that the data description, metadata description, and permanent identifiers are highly related, however, their recognition of the relation between the properties of data publication and the data submission to a repository and data peer review was relatively low. Finally, to expand the data publication, the need for the development of an editorial system that supports data paper peer review and cross-linking to a data repository as well as the development of a repository that supports data citation was identified. This study on the domestic researchers' experience and awareness of data publishing can provide insights for the implementation of data publishing services and infrastructure in the future.

A Study on the 3D Precise Modeling of Old Structures Using Merged Point Cloud from Drone Images and LiDAR Scanning Data (드론 화상 및 LiDAR 스캐닝의 정합처리 자료를 활용한 노후 구조물 3차원 정밀 모델링에 관한 연구)

  • Chan-hwi, Shin;Gyeong-jo, Min;Gyeong-Gyu, Kim;PuReun, Jeon;Hoon, Park;Sang-Ho, Cho
    • Explosives and Blasting
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    • v.40 no.4
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    • pp.15-26
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    • 2022
  • With the recent increase in old and dangerous buildings, the demand for technology in the field of structure demolition is rapidly increasing. In particular, in the case of structures with severe deformation of damage, there is a risk of deterioration in stability and disaster due to changes in the load distribution characteristics in the structure, so rapid structure demolition technology that can be efficiently dismantled in a short period of time is drawing attention. However, structural deformation such as unauthorized extension or illegal remodeling occurs frequently in many old structures, which is not reflected in structural information such as building drawings, and acts as an obstacle in the demolition design process. In this study, as an effective way to overcome the discrepancy between the structural information of old structures and the actual structure, access to actual structures through 3D modeling was considered. 3D point cloud data inside and outside the building were obtained through LiDAR and drone photography for buildings scheduled to be blasting demolition, and precision matching between the two spatial data groups was performed using an open-source based spatial information construction system. The 3D structure model was completed by importing point cloud data matched with 3D modeling software to create structural drawings for each layer and forming each member along the structure slab, pillar, beam, and ceiling boundary. In addition, the modeling technique proposed in this study was verified by comparing it with the actual measurement value for selected structure member.

A Study on the Method of Creating a Safety Vulnerable Class Distribution Diagram for Non-Structural Countermeasures in the Comprehensive Natural Disaster Reduction Plan (자연재해저감종합계획 비구조적 대책의 안전취약계층도 작성방안에 관한 연구)

  • Doo Hee Kim;In Jae Song;Byung-Sik Kim
    • Journal of Korean Society of Disaster and Security
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    • v.16 no.1
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    • pp.1-11
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    • 2023
  • The comprehensive natural disaster reduction plan, the highest plan in the disaster prevention field, was implemented by local governments. second plan is currently being formulated. In order to minimize human and property damage, structural and non-structural measures for each of the nine disaster types are established and implemented for 10 years. Structural measures are based on engineering and quantitative analysis, and the criteria for setting reduction measures are clear. Non-structural measures, however, currently lack the set criteria. the basic disaster and safety management law included the safety vulnerable class in 2018. Currently, the safety vulnerable class of the detailed establishment criteria of the comprehensive natural disaster reduction plan is being established, including children, the elderly, and the disabled. However, due to the lack of data securing and database construction by local governments, it is difficult to prepare a location map for establishing reduction measures for the safety vulnerable. Therefore, in this study, OPEN API data of the safety vulnerable class were collected and statistical information and GIS of SGIS information services were used. The distribution diagram of the safety vulnerable class in Samcheok, Gangwon-do, which is a sample area, and the distribution diagram of the safety vulnerable class in units of the output area (OA) in Geundeok-myeon were prepared.

An Analysis of the Variations of Haegeum's Timbres According to the Types of Wonsan (해금 원산의 소재에 따른 음색 변화 분석)

  • Sung, Ki-Young;Lee, You-Jung
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.8
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    • pp.291-302
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    • 2019
  • In this paper, we first looked at the structures and characteristics of the musical instrument to study the tone of haegeum, which is the only Korean musical instrument made using all the eight ingredients that make gugak instruments, and which is now the most frequently used in fusion gugak or pop music production sites. In addition, for the comparison of the various tones of the haegeum, under the same conditions, we analized how the haegeum's tone changes according to the types of Wonsan, which works as the bridge of the haegeum. Four Wonsan made of Park, Rosewood, Maple and Black Dan were used in the experiment, and low, medium, and high notes were recorded to compare the inner and outter open strings and the sound ranges. By doing so, we looked at the composition of frequency characteristics and the distribution and analyzed the timbres according to the types of Wonsan. Based on this study, it is expected to help the performers in the field choose the proper Wonsan according to each harmony part, rather than just to their tastes when performing Gugak orchestral music or haegeum ensemble. We also look forward to playing haegeum and using the timbres in various combinations of Wonsan that suit the genres at the pop music industry.

Revalidation of the Complex Trial Protocol using participant-oriented countermeasures (설문 기반 대응방안을 사용한 복합시행 프로토콜의 재평가)

  • Kim, Hyemin;Song, Inuk;Chang, Eunhee;Kim, Hyun Taek
    • Korean Journal of Forensic Psychology
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    • v.11 no.1
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    • pp.89-115
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    • 2020
  • Traditional deception detection methods had examined the difference of one's autonomic physiological responses through asking crime-related and crime-unrelated questions. There has been a continuing controversy regarding the accuracy and validity of the test, and thus, many researchers were motivated to explore and develop alternative efficient methods of detection in which one of them is known as P300-based Complex Trial Protocol (CTP). The P300-based CTP detects deception through comparing the P300 amplitudes between probe and irrelevant stimuli and is known as a counterstrategy of countermeasures. However, many previous studies have used countermeasures created from Rosenfeld et al.'s work (2008). The present study initially conducted a survey asking open-ended questions about the countermeasure use to acquire participant-oriented countermeasures for the main experiment. Then, the study aimed to evaluate whether the CTP can accurately detect deception even in the use of survey-based countermeasures. We firstly selected a set of participant-oriented countermeasures through survey questions. Then, a total of 50 participants were divided into three groups (innocent, guilty, and countermeasures) and performed the CTP. Those assigned to the countermeasures group covertly performed mental countermeasures during the CTP. The results of P300 amplitude analysis revealed that the guilty group's P300 amplitude of probe stimuli was significantly larger than that of irrelevant stimuli. Countermeasures group also had a significantly larger P300 amplitude for probe stimuli compared to irrelevant stimuli, even in the use of countermeasures. The results of bootstrapped amplitude difference (BAD) showed a detection accuracy rate of 81.25%, 82.35%, 82.35% for the innocent, guilty, and countermeasures groups, respectively. These findings demonstrate that the CTP can obtain a high detection rate in participant-oriented countermeasures and suggest the potential use of the CTP in the field.

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Effect of Silicate on Bokto Direct Seeding Technology in Rice (규산질비료 이용 벼 복토직파기술개선 연구)

  • Park, Kwang-Ho;Kang, Yun-Kyu;Ahn, Duck-Hyun
    • Journal of Practical Agriculture & Fisheries Research
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    • v.7 no.1
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    • pp.35-46
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    • 2005
  • This research was conducted to improve and establish Bokto direct seeding technology use of silicate in rice. Bokto direct seeding technology has recently released to alternative new method for transplanting method of the rice plant. In recent rice production has serious problem due to higher cost and labor shortage in Korea. In particular rice has been faced on open market to internationally due to WTO, FTA agreement etc. Thus rice growers in Korea have been more concentrated on cost reduction using by direct seeding technology such as dry seeding and water seeding while those methods have severe constraints like poor seedling, more weed occurrence, lodging and poor grain quality. In recent a new technology for improvement of these problem has released to farmer's field and proven to alternative rice growing technology of transplanting. In this technology there was additional application of silicate which has known as soil improvement and this research was obtained in the following results. At the application of silicate, sand, and soil there was high in seedling establishment by 90~100% in pot experiment but there was 55.0% seedling stand of the untreated control. Under dry condition seedling stand was 0% at the untreated control while 65~100% high in application of silicate, sand, and soil. Meanwhile, under rainy condition untreated control there was 85% of seedling stand but soil application was 20% of seedling establishment due to blocking of oxygen and physical soil blockage.

Ginsenoside Rg1 treatment protects against cognitive dysfunction via inhibiting PLC-CN-NFAT1 signaling in T2DM mice

  • Xianan Dong ;Liangliang Kong ;Lei Huang ;Yong Su ;Xuewang Li;Liu Yang;Pengmin Ji ;Weiping Li ;Weizu Li
    • Journal of Ginseng Research
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    • v.47 no.3
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    • pp.458-468
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    • 2023
  • Background: As a complication of Type II Diabetes Mellitus (T2DM), the etiology, pathogenesis, and treatment of cognitive dysfunction are still undefined. Recent studies demonstrated that Ginsenoside Rg1 (Rg1) has promising neuroprotective properties, but the effect and mechanism in diabetes-associated cognitive dysfunction (DACD) deserve further investigation. Methods: After establishing the T2DM model with a high-fat diet and STZ intraperitoneal injection, Rg1 was given for 8 weeks. The behavior alterations and neuronal lesions were judged using the open field test (OFT) and Morris water maze (MWM), as well as HE and Nissl staining. The protein or mRNA changes of NOX2, p-PLC, TRPC6, CN, NFAT1, APP, BACE1, NCSTN, and Ab1-42 were investigated by immunoblot, immunofluorescence or qPCR. Commercial kits were used to evaluate the levels of IP3, DAG, and calcium ion (Ca2+) in brain tissues. Results: Rg1 therapy improved memory impairment and neuronal injury, decreased ROS, IP3, and DAG levels to revert Ca2+ overload, downregulated the expressions of p-PLC, TRPC6, CN, and NFAT1 nuclear translocation, and alleviated Aβ deposition in T2DM mice. In addition, Rg1 therapy elevated the expression of PSD95 and SYN in T2DM mice, which in turn improved synaptic dysfunction. Conclusions: Rg1 therapy may improve neuronal injury and DACD via mediating PLC-CN-NFAT1 signal pathway to reduce Aβ generation in T2DM mice.