• Title/Summary/Keyword: Flow System

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Spatiotemporal and Longitudinal Variability of Hydro-meteorology, Basic Water Quality and Dominant Algal Assemblages in the Eight Weir Pools of Regulated River(Nakdong) (낙동강 8개 보에서 기상수문·기초수질 및 우점조류의 시공간 종적 변동성)

  • Shin, Jae-Ki;Park, Yongeun
    • Korean Journal of Ecology and Environment
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    • v.51 no.4
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    • pp.268-286
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    • 2018
  • The eutrophication and algal blooms by harmful cyanobacteria (CyanoHAs) and freshwater redtide (FRT) that severely experiencing in typical regulated weir system of the Nakdong River are one of the most rapidly expanding water quality problems in Korea and worldwide. To compare with the factors of rainfall, hydrology, and dominant algae, this study explored spatiotemporal variability of the major water environmental factors by weekly intervals in eight weir pools of the Nakdong River from January 2013 to July 2017. There was a distinct difference in rainfall distribution between upstream and downstream regions. Outflow discharge using small-scale hydropower generation, overflow and fish-ways accounted for 37.4%, 60.1% and 2.5%, respectively. Excluding the flood season, the outflow was mainly due to the hydropower release through year-round. These have been associated with the drawdown of water level, water exchange rate, and the significant impact on change of dominant algae. The mean concentration (maximum value) of chlorophyll-a was $17.6mg\;m^{-3}$ ($98.2mg\;m^{-3}$) in the SAJ~GAJ and $29.6mg\;m^{-3}$ ($193.6mg\;m^{-3}$) in the DAS~HAA weir pools reaches, respectively. It has increased significantly in the downstream part where the influence of treated wastewater effluents (TWEs) is high. Indeed, very high values (>50 or $>100mg\;m^{-3}$) of chlorophyll-a concentration were observed at low flow rates and water levels. Algal assemblages that caused the blooms of CyanoHAs and FRT were the cyanobacteria Microcystis and the diatom Stephanodiscus populations, respectively. In conclusion, appropriate hydrological management practices in terms of each weir pool may need to be developed.

The Effect of the Surfactant on the Migration and Distribution of Immiscible Fluids in Pore Network (계면활성제가 공극 구조 내 비혼성 유체의 거동과 분포에 미치는 영향)

  • Park, Gyuryeong;Kim, Seon-Ok;Wang, Sookyun
    • Economic and Environmental Geology
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    • v.54 no.1
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    • pp.105-115
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    • 2021
  • The geological CO2 sequestration in underground geological formation such as deep saline aquifers and depleted hydrocarbon reservoirs is one of the most promising options for reducing the atmospheric CO2 emissions. The process in geological CO2 sequestration involves injection of supercritical CO2 (scCO2) into porous media saturated with pore water and initiates CO2 flooding with immiscible displacement. The CO2 migration and distribution, and, consequently, the displacement efficiency is governed by the interaction of fluids. Especially, the viscous force and capillary force are controlled by geological formation conditions and injection conditions. This study aimed to estimate the effects of surfactant on interfacial tension between the immiscible fluids, scCO2 and porewater, under high pressure and high temperature conditions by using a pair of proxy fluids under standard conditions through pendant drop method. It also aimed to observe migration and distribution patterns of the immiscible fluids and estimate the effects of surfactant concentrations on the displacement efficiency of scCO2. Micromodel experiments were conducted by applying n-hexane and deionized water as proxy fluids for scCO2 and porewater. In order to quantitatively analyze the immiscible displacement phenomena by n-hexane injection in pore network, the images of migration and distribution pattern of the two fluids are acquired through a imaging system. The experimental results revealed that the addition of surfactants sharply reduces the interfacial tension between hexane and deionized water at low concentrations and approaches a constant value as the concentration increases. Also it was found that, by directly affecting the flow path of the flooding fluid at the pore scale in the porous medium, the surfactant showed the identical effect on the displacement efficiency of n-hexane at equilibrium state. The experimental observation results could provide important fundamental information on immiscible displacement of fluids in porous media and suggest the potential to improve the displacement efficiency of scCO2 by using surfactants.

The Haenam Yoon's the 8th jonbu(종부) Gwangju Lee's family management in Korean letter of Joseon era (한글편지에 나타난 해남윤씨가 8대 종부 광주이씨의 가문경영)

  • Lee, hyun-ju
    • (The)Study of the Eastern Classic
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    • no.73
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    • pp.385-414
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    • 2018
  • In this article, the women as the subject of the family management in the 19th century cataclysm, In particular, I tried to reconstruct the specific life course of a woman who has a status as a jongbu(종부) in the Korean language through the Hangul letter. The Haenam Yoon's the 8th jongbu(종부) Gwangju Lee attempted to find her own unique identity, not the male-centered social order she had learned. Because she had to live a life outside the traditional environment of traditional society because her husband died at the beginning of her marriage. She perceived herself as an independent subject that she had to find and maintain. When Gwangju Lee married and came to the family of Haenam Yun, the economic power of jong-ga(종가) was much inclined. This economic difficulty was caused by the conflict with the slaves and the decrease of tallage(地代) to the change of the slavery system which was the social flow at that time. And uncles of her husband's intervention made the economic situation of the family more difficult. She established her position as a jongbu(종부) and used the right of Adoption option(입후권) of the jongbu(종부) to establish the impoverished family. She chose adoption from distant relatives who were not children of her husband's uncles. Therefore, I was free from her husband uncle's interests. She also believed that it was most important to take control of the economic interests of her family in order to secure her authority as a jongbu(종부). She believed that she had to exercise her economic rights in order to bring slave labor, which is the most important means of sustaining the domestic economy at the time, In the absence of her husband, she established her family in the social upheaval of the nineteenth century, and took her place as a master of a family, not just a family name.

A Study on the Possibility of 'World Religion' in Daesoon Jinrihoe (대순진리회의 '세계종교' 가능성에 관한 연구)

  • Kwon, Dong-woo
    • Journal of the Daesoon Academy of Sciences
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    • v.35
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    • pp.73-107
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    • 2020
  • Daesoon Jinrihoe tends to be perceived as a 'nationalistic religion' by both internal members of the religious body and outside scholars of religious studies. However, the character of this particular nationalistic religion is rather complex. On top of emphasizing the special status of the Korean ethnic group while focusing on nationalism as a nationalistic religion, Daesoon Jinrihoe futrther asserts an implication of the universality of world religion aiming to bring relief to humankind and the world. This dynamic is one of the specificity of nationalistic religion and also the universality of world religion. However, this dual logic of specificity and universality is not characteristic of only Daesoon Jinrihoe. Many religions in the world have also exhibited duplicity as nationalistic religions and world religions. And this thesis pays attention to Sectarian Shinto as it formed in modern Japan. Kyoha Shinto formed when the modern Japanese government established the national Shinto system which had a total of 13 sects. Most of them do not only call themselves a nationalistic religion, inheriting the ethnic tradition of Japanese people, but also jump into overseas missionary work. This started during the Sino-Japanese and Russo-Japanese Wars. With that in mind, how did the overseas missionary work of Sectarian Shinto aspire for status as a world religion while maintaining their identities as nationalistic religions? Furthermore, how did their movements fare in their efforts to become world religions? Thus, this thesis aims to examine the possibility Daesoon Jinrihoe becoming a world religion through some cases of Sectarian Shinto that showed the duplicity as nationalistic religions and world religions. Also, this thesis makes suggestions regarding the future direction of Daesoon Jinrihoe. As such, this paper aims to review the new direction of Daesoon Jinrihoe as it stands on the borderline between being a nationalistic religion and a world religion. This is done by examining the historical flow of theory regarding 'nationalistic religion' or 'minjung religion' which have long been discussed in Korean society. Also examined is the case of Won Buddhism which likewise aims to simultaneosuly be both a nationalistic religion in Korea and a world religion abroad.

Spectral Induced Polarization Characteristics of Rocks in Gwanin Vanadiferous Titanomagnetite (VTM) Deposit (관인 함바나듐 티탄철광상 암석의 광대역 유도분극 특성)

  • Shin, Seungwook
    • Geophysics and Geophysical Exploration
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    • v.24 no.4
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    • pp.194-201
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    • 2021
  • Induced polarization (IP) effect is known to be caused by electrochemical phenomena at interface between minerals and pore water. Spectral induced polarization (SIP) method is an electrical survey to localize subsurface IP anomalies while injecting alternating currents of multiple frequencies into the ground. This method was effectively applied to mineral exploration of various ore deposits. Titanomagnetite ores were being produced by a mining company located in Gonamsan area, Gwanin-myeon, Pocheon-si, Gyeonggi-do, South Korea. Because the ores contain more than 0.4 w% vanadium, the ore deposit is called as Gwanin vanadiferous titanomagnetite (VTM) deposit. The vanadium is the most important of materials in production of vanadium redox flow batteries, which can be appropriately used for large-scale energy storage system. Systematic mineral exploration was conducted to identify presence of hidden VTM orebodies and estimate their potential resources. In geophysical exploration, laboratory geophysical measurement of rock samples is helpful to generate reliable property models from field survey data. Therefore, we performed laboratory SIP data of the rocks from the Gwanin VTM deposit to understand SIP characteristics between ores and host rocks and then demonstrate the applicability of this method for the mineral exploration. Both phase and resistivity spectra of the ores sampled from underground outcrop and drilling cores were different of those of the host rocks consisting of monzodiorite and quartz monzodiorite. Because the phase and resistivity at frequencies below 100 Hz are mainly dependent on the SIP characteristics of the rocks, we calculated mean values of the ores and the host rocks. The average phase values at 0.1 Hz were ores: -369 mrad and host rocks: -39 mrad. The average resistivity values at 0.1 Hz were ores: 16 Ωm and host rocks: 2,623 Ωm. Because the SIP characteristics of the ores were different of those of the host rocks, we considered that the SIP survey is effective for the mineral exploration in vanadiferous titanomagnetite deposits and the SIP characteristics are useful for interpreting field survey data.

Knowledge graph-based knowledge map for efficient expression and inference of associated knowledge (연관지식의 효율적인 표현 및 추론이 가능한 지식그래프 기반 지식지도)

  • Yoo, Keedong
    • Journal of Intelligence and Information Systems
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    • v.27 no.4
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    • pp.49-71
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    • 2021
  • Users who intend to utilize knowledge to actively solve given problems proceed their jobs with cross- and sequential exploration of associated knowledge related each other in terms of certain criteria, such as content relevance. A knowledge map is the diagram or taxonomy overviewing status of currently managed knowledge in a knowledge-base, and supports users' knowledge exploration based on certain relationships between knowledge. A knowledge map, therefore, must be expressed in a networked form by linking related knowledge based on certain types of relationships, and should be implemented by deploying proper technologies or tools specialized in defining and inferring them. To meet this end, this study suggests a methodology for developing the knowledge graph-based knowledge map using the Graph DB known to exhibit proper functionality in expressing and inferring relationships between entities and their relationships stored in a knowledge-base. Procedures of the proposed methodology are modeling graph data, creating nodes, properties, relationships, and composing knowledge networks by combining identified links between knowledge. Among various Graph DBs, the Neo4j is used in this study for its high credibility and applicability through wide and various application cases. To examine the validity of the proposed methodology, a knowledge graph-based knowledge map is implemented deploying the Graph DB, and a performance comparison test is performed, by applying previous research's data to check whether this study's knowledge map can yield the same level of performance as the previous one did. Previous research's case is concerned with building a process-based knowledge map using the ontology technology, which identifies links between related knowledge based on the sequences of tasks producing or being activated by knowledge. In other words, since a task not only is activated by knowledge as an input but also produces knowledge as an output, input and output knowledge are linked as a flow by the task. Also since a business process is composed of affiliated tasks to fulfill the purpose of the process, the knowledge networks within a business process can be concluded by the sequences of the tasks composing the process. Therefore, using the Neo4j, considered process, task, and knowledge as well as the relationships among them are defined as nodes and relationships so that knowledge links can be identified based on the sequences of tasks. The resultant knowledge network by aggregating identified knowledge links is the knowledge map equipping functionality as a knowledge graph, and therefore its performance needs to be tested whether it meets the level of previous research's validation results. The performance test examines two aspects, the correctness of knowledge links and the possibility of inferring new types of knowledge: the former is examined using 7 questions, and the latter is checked by extracting two new-typed knowledge. As a result, the knowledge map constructed through the proposed methodology has showed the same level of performance as the previous one, and processed knowledge definition as well as knowledge relationship inference in a more efficient manner. Furthermore, comparing to the previous research's ontology-based approach, this study's Graph DB-based approach has also showed more beneficial functionality in intensively managing only the knowledge of interest, dynamically defining knowledge and relationships by reflecting various meanings from situations to purposes, agilely inferring knowledge and relationships through Cypher-based query, and easily creating a new relationship by aggregating existing ones, etc. This study's artifacts can be applied to implement the user-friendly function of knowledge exploration reflecting user's cognitive process toward associated knowledge, and can further underpin the development of an intelligent knowledge-base expanding autonomously through the discovery of new knowledge and their relationships by inference. This study, moreover than these, has an instant effect on implementing the networked knowledge map essential to satisfying contemporary users eagerly excavating the way to find proper knowledge to use.

Review of Erosion and Piping in Compacted Bentonite Buffers Considering Buffer-Rock Interactions and Deduction of Influencing Factors (완충재-근계암반 상호작용을 고려한 압축 벤토나이트 완충재 침식 및 파이핑 연구 현황 및 주요 영향인자 도출)

  • Hong, Chang-Ho;Kim, Ji-Won;Kim, Jin-Seop;Lee, Changsoo
    • Tunnel and Underground Space
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    • v.32 no.1
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    • pp.30-58
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    • 2022
  • The deep geological repository for high-level radioactive waste disposal is a multi barrier system comprised of engineered barriers and a natural barrier. The long-term integrity of the deep geological repository is affected by the coupled interactions between the individual barrier components. Erosion and piping phenomena in the compacted bentonite buffer due to buffer-rock interactions results in the removal of bentonite particles via groundwater flow and can negatively impact the integrity and performance of the buffer. Rapid groundwater inflow at the early stages of disposal can lead to piping in the bentonite buffer due to the buildup of pore water pressure. The physiochemical processes between the bentonite buffer and groundwater lead to bentonite swelling and gelation, resulting in bentonite erosion from the buffer surface. Hence, the evaluation of erosion and piping occurrence and its effects on the integrity of the bentonite buffer is crucial in determining the long-term integrity of the deep geological repository. Previous studies on bentonite erosion and piping failed to consider the complex coupled thermo-hydro-mechanical-chemical behavior of bentonite-groundwater interactions and lacked a comprehensive model that can consider the complex phenomena observed from the experimental tests. In this technical note, previous studies on the mechanisms, lab-scale experiments and numerical modeling of bentonite buffer erosion and piping are introduced, and the future expected challenges in the investigation of bentonite buffer erosion and piping are summarized.

A Study on the Influence of Workers' Aspiration for Academic Needs on Participation in University Education (근로자의 학업욕구 열망이 대학교육 참여에 미치는 영향에 관한 연구)

  • Lee, Ji-Hun;Mun, Bok-Hyun
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.3
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    • pp.231-241
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    • 2021
  • This study intended to present strategies and implications for attracting new students and customized education to university officials through research on the participation of workers' academic aspirations in university education. Thus, variables were derived by analyzing prior data, and causal settings between variables and questionnaires were developed. Subject to the survey, 331 workers interested in participating in university education were collected through interpersonal interviews. The collected data were dataized, and reliability and feasibility verification and frequency analysis were conducted. Finally, we validate the fit of the structural equation model and the causal relationship for each concept. Therefore, the results of the validation show the following implications. First, university officials should be motivated by a mentor and mentee system with experienced people who have switched to a suitable vocational group through university education. It will also be necessary to develop and disseminate programs so that they can continue to develop themselves for the future. To this end, it will be necessary to help them understand their aptitude and strengths through consultation with experts. Second, university officials should strengthen public relations so that prospective students can know the cases and information of the job transformation of the admitted workers through recommendations. It will also be necessary to develop university education programs that can self-develop, accept various ideas through "public contest", and provide accurate information about university education to workers through re-processing. Third, university officials should provide workers with a program that allows them to catch two rabbits: job transformation and self-improvement through university education. In other words, it is necessary to stimulate the motivation of workers by providing various information such as visiting advanced overseas companies, obtaining various certificates, moving between departments of blue-collar and white-collar, and transfer opportunities. Fourth, university officials should actively promote university education programs related to this by participating in university education and receiving systematic education and the flow of social environment. Finally, university officials will need to consult and promote workers so that they can self-develop when they participate in college education, and they will have to figure out what they need for self-development through demand surveys and analysis.

The Effect of Domain Specificity on the Performance of Domain-Specific Pre-Trained Language Models (도메인 특수성이 도메인 특화 사전학습 언어모델의 성능에 미치는 영향)

  • Han, Minah;Kim, Younha;Kim, Namgyu
    • Journal of Intelligence and Information Systems
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    • v.28 no.4
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    • pp.251-273
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    • 2022
  • Recently, research on applying text analysis to deep learning has steadily continued. In particular, researches have been actively conducted to understand the meaning of words and perform tasks such as summarization and sentiment classification through a pre-trained language model that learns large datasets. However, existing pre-trained language models show limitations in that they do not understand specific domains well. Therefore, in recent years, the flow of research has shifted toward creating a language model specialized for a particular domain. Domain-specific pre-trained language models allow the model to understand the knowledge of a particular domain better and reveal performance improvements on various tasks in the field. However, domain-specific further pre-training is expensive to acquire corpus data of the target domain. Furthermore, many cases have reported that performance improvement after further pre-training is insignificant in some domains. As such, it is difficult to decide to develop a domain-specific pre-trained language model, while it is not clear whether the performance will be improved dramatically. In this paper, we present a way to proactively check the expected performance improvement by further pre-training in a domain before actually performing further pre-training. Specifically, after selecting three domains, we measured the increase in classification accuracy through further pre-training in each domain. We also developed and presented new indicators to estimate the specificity of the domain based on the normalized frequency of the keywords used in each domain. Finally, we conducted classification using a pre-trained language model and a domain-specific pre-trained language model of three domains. As a result, we confirmed that the higher the domain specificity index, the higher the performance improvement through further pre-training.

Analysis of Munitions Contract Work Using Process Mining (프로세스 마이닝을 이용한 군수품 계약업무 분석 : 공군 군수사 계약업무를 중심으로)

  • Joo, Yong Seon;Kim, Su Hwan
    • Journal of Intelligence and Information Systems
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    • v.28 no.4
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    • pp.41-59
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    • 2022
  • The timely procurement of military supplies is essential to maintain the military's operational capabilities, and contract work is the first step toward timely procurement. In addition, rapid signing of a contract enables consumers to set a leisurely delivery date and increases the possibility of budget execution, so it is essential to improve the contract process to prevent early execution of the budget and transfer or disuse. Recently, research using big data has been actively conducted in various fields, and process analysis using big data and process mining, an improvement technique, are also widely used in the private sector. However, the analysis of contract work in the military is limited to the level of individual analysis such as identifying the cause of each problem case of budget transfer and disuse contracts using the experience and fragmentary information of the person in charge. In order to improve the contract process, this study analyzed using the process mining technique with data on a total of 560 contract tasks directly contracted by the Department of Finance of the Air Force Logistics Command for about one year from November 2019. Process maps were derived by synthesizing distributed data, and process flow, execution time analysis, bottleneck analysis, and additional detailed analysis were conducted. As a result of the analysis, it was found that review/modification occurred repeatedly after request in a number of contracts. Repeated reviews/modifications have a significant impact on the delay in the number of days to complete the cost calculation, which has also been clearly revealed through bottleneck visualization. Review/modification occurs in more than 60% of the top 5 departments with many contract requests, and it usually occurs in the first half of the year when requests are concentrated, which means that a thorough review is required before requesting contracts from the required departments. In addition, the contract work of the Department of Finance was carried out in accordance with the procedures according to laws and regulations, but it was found that it was necessary to adjust the order of some tasks. This study is the first case of using process mining for the analysis of contract work in the military. Based on this, if further research is conducted to apply process mining to various tasks in the military, it is expected that the efficiency of various tasks can be derived.