• Title/Summary/Keyword: Fundamental performance

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Review on Rock-Mechanical Models and Numerical Analyses for the Evaluation on Mechanical Stability of Rockmass as a Natural Barriar (천연방벽 장기 안정성 평가를 위한 암반역학적 모델 고찰 및 수치해석 검토)

  • Myung Kyu Song;Tae Young Ko;Sean S. W., Lee;Kunchai Lee;Byungchan Kim;Jaehoon Jung;Yongjin Shin
    • Tunnel and Underground Space
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    • v.33 no.6
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    • pp.445-471
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    • 2023
  • Long-term safety over millennia is the top priority consideration in the construction of disposal sites. However, ensuring the mechanical stability of deep geological repositories for spent fuel, a.k.a. radwaste, disposal during construction and operation is also crucial for safe operation of the repository. Imposing restrictions or limitations on tunnel support and lining materials such as shotcrete, concrete, grouting, which might compromise the sealing performance of backfill and buffer materials which are essential elements for the long-term safety of disposal sites, presents a highly challenging task for rock engineers and tunnelling experts. In this study, as part of an extensive exploration to aid in the proper selection of disposal sites, the anticipation of constructing a deep geological repository at a depth of 500 meters in an unknown state has been carried out. Through a review of 2D and 3D numerical analyses, the study aimed to explore the range of properties that ensure stability. Preliminary findings identified the potential range of rock properties that secure the stability of central and disposal tunnels, while the stability of the vertical tunnel network was confirmed through 3D analysis, outlining fundamental rock conditions necessary for the construction of disposal sites.

Approaches to Applying Social Network Analysis to the Army's Information Sharing System: A Case Study (육군 정보공유체계에 사회관계망 분석을 적용하기 위한방안: 사례 연구)

  • GunWoo Park
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.5
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    • pp.597-603
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    • 2023
  • The paradigm of military operations has evolved from platform-centric warfare to network-centric warfare and further to information-centric warfare, driven by advancements in information technology. In recent years, with the development of cutting-edge technologies such as big data, artificial intelligence, and the Internet of Things (IoT), military operations are transitioning towards knowledge-centric warfare (KCW), based on artificial intelligence. Consequently, the military places significant emphasis on integrating advanced information and communication technologies (ICT) to establish reliable C4I (Command, Control, Communication, Computer, Intelligence) systems. This research emphasizes the need to apply data mining techniques to analyze and evaluate various aspects of C4I systems, including enhancing combat capabilities, optimizing utilization in network-based environments, efficiently distributing information flow, facilitating smooth communication, and effectively implementing knowledge sharing. Data mining serves as a fundamental technology in modern big data analysis, and this study utilizes it to analyze real-world cases and propose practical strategies to maximize the efficiency of military command and control systems. The research outcomes are expected to provide valuable insights into the performance of C4I systems and reinforce knowledge-centric warfare in contemporary military operations.

A Study on the Expansion of Stage Costumes in the Contemporary Ballet Play <'That' Girl> (창작 발레극 <'그' 소녀> 에 나타난 무대의상의 확장성 연구)

  • Jinyoung Ryu;Sojung Chang
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.5
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    • pp.779-785
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    • 2023
  • In the creation of non-verbal dance performance, stage costumes are an important element of visual expression and serve an expanded role in addition to its fundamental decorativeness, representation of status reflective of the historical setting of the act and functionality for the dance movement. We intends that the purpose of this research is to analyze the expanded role of the costumes in the creative ballet <'That' Girl>, and through this exercise, provide foundational data on and suggest new future directions for stage costume design. <'That' Girl> is composed of two acts, offering condolences and eliciting empathy by conveying the fear experienced by the victims of the time. The second dance act representing freedom and "Haan" requires this expanded application of costume design. The costume design was inspired by the "Statue of Peace" representing comfort women, and completed through three draft designs and material experiments testing the ease of operation of the strings and fabrics installed in the costumes as well as the functionality of the associated ballet movements. In conclusion, expansion of time & space, expansion of form and expansion of symbolic expression were shown in the dance of liberation using strings wrapped around the arms and through the cloth embodying 'Haan' hidden in front of the costume.

Exploring the power of physics-informed neural networks for accurate and efficient solutions to 1D shallow water equations (물리 정보 신경망을 이용한 1차원 천수방정식의 해석)

  • Nguyen, Van Giang;Nguyen, Van Linh;Jung, Sungho;An, Hyunuk;Lee, Giha
    • Journal of Korea Water Resources Association
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    • v.56 no.12
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    • pp.939-953
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    • 2023
  • Shallow water equations (SWE) serve as fundamental equations governing the movement of the water. Traditional numerical approaches for solving these equations generally face various challenges, such as sensitivity to mesh generation, and numerical oscillation, or become more computationally unstable around shock and discontinuities regions. In this study, we present a novel approach that leverages the power of physics-informed neural networks (PINNs) to approximate the solution of the SWE. PINNs integrate physical law directly into the neural network architecture, enabling the accurate approximation of solutions to the SWE. We provide a comprehensive methodology for formulating the SWE within the PINNs framework, encompassing network architecture, training strategy, and data generation techniques. Through the results obtained from experiments, we found that PINNs could be an accurate output solution of SWE when its results were compared with the analytical method. In addition, PINNs also present better performance over the Artificial Neural Network. This study highlights the transformative potential of PINNs in revolutionizing water resources research, offering a new paradigm for accurate and efficient solutions to the SVE.

Field-effect Transistors Based on a Van der Waals Vertical Heterostructure Using CVD-grown Graphene and MoSe2 (화학기상증착법을 통해 합성된 그래핀 및 MoSe2를 이용한 반데르발스 수직이종접합 전계효과 트랜지스터)

  • Seon Yeon Choi;Eun Bee Ko;Seong Kyun Kwon;Min Hee Kim;Seol Ah Kim;Ga Eun Lee;Min Cheol Choi;Hyun Ho Kim
    • Journal of Adhesion and Interface
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    • v.24 no.3
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    • pp.100-104
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    • 2023
  • Van der Waals heterostructures have garnered significant attention in recent research due to their excellent electronic characteristics arising from the absence of dangling bonds and the exclusive reliance on Van der Waals forces for interlayer coupling. However, most studies have been confined to fundamental research employing the Scotch tape (mechanical exfoliation) method. We fabricated Van der Waals vertical heterojunction transistors to advance this field using materials exclusively grown via chemical vapor deposition (CVD). CVDgrown graphene was patterned through photolithography to serve as electrodes, while CVD-grown MoSe2 was employed as the pickup/transfer material, resulting in the realization of Van der Waals heterojunction transistors with interlayer charge transfer effects. The electrical characteristics of the fabricated devices were thoroughly examined. Additionally, we observed variations in the transistor's performance based on the presence of defects in MoSe2 layer.

A Multiple Case Study on the Relationship Between School Music Experiences and Motivation for Music Engagement Among Adults in 20s (학교 음악 경험과 20대 성인의 음악 생활화 동기에 관한 다중사례 연구)

  • Choi, Chi Hyun;Jung, Joo Yeon
    • Journal of Music and Human Behavior
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    • v.21 no.1
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    • pp.1-27
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    • 2024
  • This study investigates the link between music integration in the lives of adults in their twenties and their school music experiences. Ten individuals in their twenties were interviewed to explore their experiences based on the self-determination theory's fundamental psychological needs (autonomy, competence, and relatedness). Participants were categorized into an active music engagement group (5 individuals) and an inactive group (5 individuals) for individual interviews. Transcripts were analyzed following the five steps of grounded theory data analysis technique. Results indicated a strong connection between music activities during school years and current motivation for music integration, associated with the fulfillment of psychological needs outlined in the self-determination theory. Particularly, this study identified the instructional methods, school music activities, and performance evaluations as closely related to autonomy, competence, and relatedness. It offers a comprehensive analysis of how experiences in these areas during school music activities correlate with values and motivations for music integration in adulthood. Additionally, the study suggests ways to promote the voluntary incorporation of music into life through positive experiences of autonomy, competence, and relatedness in music activities.

Analysis of the Stage and Performance Elements for Bongsudang-jinchan Banquet in Joseon Dynasty (봉수당진찬(奉壽堂進饌)의 무대와 공연 요소 분석)

  • Song, Hye-jin
    • (The) Research of the performance art and culture
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    • no.18
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    • pp.413-444
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    • 2009
  • This paper is an analysis of stage and performance elements for the ceremonial procedures and dance featured in bongsudang-jinchan, a feast celebrating the 60th birthday of Hyegyeong-gung Hongssi (Crown Princess Hong of Hyegyeonggung), the mother of King Jeongjo, which took place in Hwaseong haegung palace in 1795. The primary sources used are data on bongsudangjinchan recorded in Wonhaeng-eulmyojeongriuigwe, Jeongjo-sillok, Hongjae-jeonseo, pictorial sources such as Folding Screens of Hwaseong-neunghaeng and Hwaseong Ilgi, which is a journal in Korean by Yi Hui-pyeong. A court ceremony to offer music, dance, flowers, and food, as well as wine and poetry which express the sentiments of chung (fidelity) and hyo (filial piety) was considered a national ceremony and has constituted a unique musical culture during the 500 years of Joseon dynasty. However, after the fall of Joseon dynasty, ceremonial music and dance, which have been organically linked within the overall symbolic system of ye (courtesy), became scattered to become independent 'pieces.' As a result, all of their philosophy, principles, and the time-space interpretation of court music and dance became greatly reduced, leaving only the artistic expression and formal structure of the music and dance to become emphasized. Since the 1990s, there has been many research and events aiming to re-create the court ceremonial tradition, resulting in the increase of the related performance activities. This is especially true with bongsudang-jinchan, which is now being performed on modern stage in various forms. However there are still many problems to be solved, such as the issue of re-creating and restoring the original, and the question of artistic value found in the traditional pieces. Until now, much focus has been paid to the outer re-construction of uiju document as recorded in Wonhaeng-eulmyo-jeongriuigwe. On the other hand, there lacked an in-depth study which analyzes the stage situation and performance elements. Therefore in this paper, after focusing on the stage structure and performance elements, it is concluded that bongsudang-jinchan, the only court feast to be held in Haeng gung, not only consists of the fundamental aspects of court performance principle as 'governing through ye and ak (music),' but also served as an important occasion to bring together the sovereign and the subject. Bongsudang-jinchan had features of both naeyeon (feast for ladies) and oeyeon (feast for gentlemen). It minimized the use of screens and allowed every guest to enjoy food, music, and dance together, but provided a separate tent for foreign guests, maintaining the ideal balance between equality and distinction among different gender and social status. A screen symbolizing the venue for the feast is placed for all of the government officials. The king then pronounces the beginning of the banquet in which the ideal of gunsin-dongyeon (king and officials dining together) is realized. This indicates that bongsudang-jinchan, compared to other court ceremonies that emphasize the principle of yeak (courtesy and music), focuses more on the spirit of harmony and rapprochement. The king played a more active role in bongsudang-jinchan than in any other royal feasts. Examples as recorded in uiju documents are; Jeongjo's conversation with his retainers after the 7th wine, king's bestowing of food and flowers to the officials, writing his own majesty's poems with regard to the festival, and asking the retainers to write replying poems. All these played an important part in making the occasion more rich, extensive, and meaningful. Moreover, as analysis of the structure of orchestral music and court dance featured in bongsudang-jinchan shows, it was like any other court banquet in that it employed minimal use of extravagance in movements and conversation. However, the colors and tonal texture used in the music and dance were more brilliant in this case. Compared to other banquets that took place before king Jeongjo, the dance style was more diverse, which included some of the latest additions. There were past performances arranged anew. Noteworthy are; the incorporation of "Seonyurak (Boat Dance)" and "Geommu (Sword Dance)," traditionally used for local officials and civilians feast, to suit the court taste; and the use of saenghwang (mouth organ), which was a rising instrument in pungnyubang (literati's private salon), for "Hakmu (Cranes Dance)." This especially indicates the nature of the 'open structure' pursued by the court banquets at the time, which strove to break away from the traditional rules and customs and accept something new.

A Study on Risk Parity Asset Allocation Model with XGBoos (XGBoost를 활용한 리스크패리티 자산배분 모형에 관한 연구)

  • Kim, Younghoon;Choi, HeungSik;Kim, SunWoong
    • Journal of Intelligence and Information Systems
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    • v.26 no.1
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    • pp.135-149
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    • 2020
  • Artificial intelligences are changing world. Financial market is also not an exception. Robo-Advisor is actively being developed, making up the weakness of traditional asset allocation methods and replacing the parts that are difficult for the traditional methods. It makes automated investment decisions with artificial intelligence algorithms and is used with various asset allocation models such as mean-variance model, Black-Litterman model and risk parity model. Risk parity model is a typical risk-based asset allocation model which is focused on the volatility of assets. It avoids investment risk structurally. So it has stability in the management of large size fund and it has been widely used in financial field. XGBoost model is a parallel tree-boosting method. It is an optimized gradient boosting model designed to be highly efficient and flexible. It not only makes billions of examples in limited memory environments but is also very fast to learn compared to traditional boosting methods. It is frequently used in various fields of data analysis and has a lot of advantages. So in this study, we propose a new asset allocation model that combines risk parity model and XGBoost machine learning model. This model uses XGBoost to predict the risk of assets and applies the predictive risk to the process of covariance estimation. There are estimated errors between the estimation period and the actual investment period because the optimized asset allocation model estimates the proportion of investments based on historical data. these estimated errors adversely affect the optimized portfolio performance. This study aims to improve the stability and portfolio performance of the model by predicting the volatility of the next investment period and reducing estimated errors of optimized asset allocation model. As a result, it narrows the gap between theory and practice and proposes a more advanced asset allocation model. In this study, we used the Korean stock market price data for a total of 17 years from 2003 to 2019 for the empirical test of the suggested model. The data sets are specifically composed of energy, finance, IT, industrial, material, telecommunication, utility, consumer, health care and staple sectors. We accumulated the value of prediction using moving-window method by 1,000 in-sample and 20 out-of-sample, so we produced a total of 154 rebalancing back-testing results. We analyzed portfolio performance in terms of cumulative rate of return and got a lot of sample data because of long period results. Comparing with traditional risk parity model, this experiment recorded improvements in both cumulative yield and reduction of estimated errors. The total cumulative return is 45.748%, about 5% higher than that of risk parity model and also the estimated errors are reduced in 9 out of 10 industry sectors. The reduction of estimated errors increases stability of the model and makes it easy to apply in practical investment. The results of the experiment showed improvement of portfolio performance by reducing the estimated errors of the optimized asset allocation model. Many financial models and asset allocation models are limited in practical investment because of the most fundamental question of whether the past characteristics of assets will continue into the future in the changing financial market. However, this study not only takes advantage of traditional asset allocation models, but also supplements the limitations of traditional methods and increases stability by predicting the risks of assets with the latest algorithm. There are various studies on parametric estimation methods to reduce the estimated errors in the portfolio optimization. We also suggested a new method to reduce estimated errors in optimized asset allocation model using machine learning. So this study is meaningful in that it proposes an advanced artificial intelligence asset allocation model for the fast-developing financial markets.

Study on the Improvement of Stow Net Fishing Technique and the Enlargement of Fishing Ground to the Distant Waters - 3 . Field Experiment on the Efficiency of Newly Designed Net and the Stern Operation System (안강망어법의 개량과 어장의 원해로의 확대를 위한 연구 - 3 . 시험어구의 전개성능과 선미식 어업방법에 관한 해상시험 -)

  • 이병기
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.25 no.2
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    • pp.75-81
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    • 1989
  • In this paper, the authors describe on the field experiment of the newly designed actual stow net, standing on the result of the model experiment to examine the performance of the conventional net and the newly designed net, presented in two previous reports of this series. Concurrently the additional experiment to find out the possibility of changing of operating system from the side to the stern was carried out. 1. Fundamental shape of the experimented net was 20 times aslarge asthe newly designed model net. Performance of the net was detected by using two ultrasonic echo sounders: one was set downward at the top-most spreader of the shearing device to detect the opening height of the device from the sea bed, and the other sidewise at the starboard top-most spreader to detect the top-most opening width of the devices. Opening height of the newly designed net showed about 3m smaller than the conventional net at slow current of 0.6m/sec and less but it overcome 1m at speedy current of 0.8m/sec and more. Opening width of the newly designed net was 1.4 times as large as that of the conventional net, ant the front projection area of the newly designed net mouth was estimated as 1.3~1.6 times as large as that of the conventional net. 2. The experiment on the stern operating system was tightly limited by the structure of the ship employed in the experiment, which was a stern trawler of 2275 GT. The ship confronted by the wind with main anchor, while the net was put over the stern slipway and the hauling line of shearing device was operated through the top rollers of gallows. The experiment was very suggestive in the view point to mechanize the operating system, and so to decrease the man power except the following question. The of bow-stern line of ship, and that of net is much different.

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Quantitative Analysis of Amino Acids of Paragonimus Westermani Treated with Praziquantel in Vivo and in Vitro (간흡충(肝吸蟲) 성충(成蟲)에 대한 Praziquantel의 시험관내 살충작용(殺蟲作用)에 의한 유리(遊離) 아미노산(酸)의 정량분석(定量分析))

  • Tak, Byung-Yun;Chung, Myung-Sook;Joo, Kyoung-Hwan;Rim, Han-Jong
    • Journal of agricultural medicine and community health
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    • v.16 no.2
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    • pp.134-140
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    • 1991
  • The amino acid constituents of Paragonimus westermani were very imperfectively known. Lee(1964) detected 9 amino acids in the tissue hydrolysates of P. westermani, and 13 amino acids were detected from the cyst content and body fluid constituents of P. ohirai, But, the quantity of amino acids in P. westermani is still unknown. In the present investigation 18 amino acids, the fundamental constituents of proteins, were quantitatively studied by high performance liquid chromatography. The results obtained were as follows : A total of 18 amino acids were recovered in protein hydrolysates of P. westermani obtained from cat. ; They were cystein, aspartic acid, glutamic acid, serine. glycine, histidine. arginine, threonine, alanine, proline, tyrosine, valine, methionine, isoleucine, leucine, phenylalanine, tryptophan and lysin. Among them, glutamic acid was the most abundant form and tryptophan, cystein, methionine, and histidine constitute minor portion of hydrolysates. Compared to the normal P. westermani, the volume of hydrolysates obtained from the praziquantel(PZQ) treated worm-0.lug PZQ/ml saline for 6 hours incubation, and $3{\times}25$mg/kg bwt${\times}$2days in vivo treatment was generally increased except tryptophan. A total of 17 free amino acids were identified and the volume was 174.18 umol/1 gm wet weight P. westermaini. Among them, glycine and alanine constitute 28% of total volume. No significant differences were observed in the material obtained from worm treated with PZQ. However, slight increase of serine, arginine and the slight diminution of glutamic acid and proline was observed.

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