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Comparative Study of PI, FNN and ALM-FNN for High Control of Induction Motor Drive (유도전동기 드라이브의 고성능 제어를 위한 PI, FNN 및 ALM-FNN 제어기의 비교연구)

  • Kang, Sung-Jun;Ko, Jae-Sub;Choi, Jung-Sik;Jang, Mi-Geum;Back, Jung-Woo;Chung, Dong-Hwa
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2009.05a
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    • pp.408-411
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    • 2009
  • In this paper, conventional PI, fuzzy neural network(FNN) and adaptive teaming mechanism(ALM)-FNN for rotor field oriented controlled(RFOC) induction motor are studied comparatively. The widely used control theory based design of PI family controllers fails to perform satisfactorily under parameter variation nonlinear or load disturbance. In high performance applications, it is useful to automatically extract the complex relation that represent the drive behaviour. The use of learning through example algorithms can be a powerful tool for automatic modelling variable speed drives. They can automatically extract a functional relationship representative of the drive behavior. These methods present some advantages over the classical ones since they do not rely on the precise knowledge of mathematical models and parameters. Comparative study of PI, FNN and ALM-FNN are carried out from various aspects which is dynamic performance, steady-state accuracy, parameter robustness and complementation etc. To have a clear view of the three techniques, a RFOC system based on a three level neutral point clamped inverter-fed induction motor drive is established in this paper. Each of the three control technique: PI, FNN and ALM-FNN, are used in the outer loops for rotor speed. The merit and drawbacks of each method are summarized in the conclusion part, which may a guideline for industry application.

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Estimation of greenhouse gas (GHG) emission from wastewater treatment plants and effect of biogas reuse on GHG mitigation

  • Chang, Jin;Kyung, Daeseung;Lee, Woojin
    • Advances in environmental research
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    • v.3 no.2
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    • pp.173-183
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    • 2014
  • A comprehensive mathematical model was developed for this study to estimate on-site and off-site GHG emissions from wastewater treatment plants (WWTPs). The model was applied to three different hybrid WWTPs (S-WWTP, J-WWTP, and T-WWTP) including anaerobic, anoxic, and aerobic process, located in Seoul City, South Korea. Overall on-site and off-site GHG emissions from S-WWTP, J-WWTP, and T-WWTP were $305,253kgCO_2e/d$, $282,682kgCO_2e/d$, and $117,942kgCO_2e/d$, respectively. WWTP treating higher amounts of wastewater produced more on-site and off-site GHG emissions. On average, the percentage contribution of on-site and off-site emissions was 3.03% and 96.97%. The highest amount of on-site GHG emissions was generated from anoxic process and the primary on-site GHG was nitrous oxide ($N_2O$). Off-site GHG emissions related to electricity consumption for unit operation was much higher than that related to production of chemicals for on-site usage. Recovery and reuse of biogas significantly reduced the total GHG emissions from WWTPs. The results obtained from this study can provide basic knowledge to understand the source and amount of GHG emissions from WWTPs and strategies to establish lower GHG emitting WWTPs.

A Study on the Instructional Model utilizing Scratch for Introductory Programming Classes of SW-Major Students (SW전공자 프로그래밍 입문 수업의 스크래치 활용 수업 모형 연구)

  • KO, Kwangil
    • Convergence Security Journal
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    • v.18 no.2
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    • pp.59-67
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    • 2018
  • The programming language is a core education area of software that is becoming increasingly important in the age of the fourth industrial revolution, but it requires mathematical knowledge and logical thinking skills, so that many local private university and college students with low basic skills are having difficulties learning it. This problem occasionally causes SW-major students to lose interest and confidence in their majors during the introductory course of programming languages; making them change their majors, or give up their studies. In this study, we designed an instructional model using Scratch for educating C-language which is a typical programming introductory language. To do this, we analyzed the concepts that can be trained by Scratch among the programming concepts supported by C-language, and developed the examples of Scratch for exercising the concepts. In addition, we designed an instructional model, by which the programming concepts are first learned through Scratch and then C-language is taught, and conducted an experiment on the SW-major freshman students of a local private university to verify the effectiveness of the model. In the situation where SW education is becoming common, we expect that this study will help programming language education of security IT students.

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"The Architecture of Movement" Considered in the Viewpoint of Communicative Space - A Case Study of Zaha Hadid's Design Theory and Practice - (소통공간의 관점에서 고찰한 "움직임의 건축" - 자하 하디드의 설계이론과 작품 사례연구 -)

  • Seo, Jeongil
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.11
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    • pp.125-134
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    • 2018
  • This study examines Dalibor Vesely's theoretical proposition of communicative space and tries to develop it through a review of the contemporary architectural case. Vesely poses a critical question about communication: how do the situational conditions of our everyday life and the spatial characteristics of the natural world in which we live communicate through representation. He emphasizes the spatial and situational conditions and the role of representation in communication, arguing that architecture should create the formation of communicative space to restore its primary role as the corporeal foundation of culture. This study thus focuses on one of the critical concepts of his theory: "the communicative movement," which is, according to him, ontological and situational because it animates and transforms human circumstances as a whole. Further, it pursues some practical knowledge of creating the communicative space, by examining the design theory and practice of Zaha Hadid, who thematizes communication and movement in her architectural approach. This study analyses the different levels of representation and modes of movement in her architectural space to reveal the possibilities and limits of its communicative roles. We will find that the representation of Hadid's architectural space is not the formal representation of reality, but a mathematical and projective representation of abstract concepts. Despite its apparent aesthetic consistency, the inward and self-referential relation between the individual elements of the architectural space reveals its limit for the communicative space.

Research on Embodied Carbon Emission in Sino-Korea Trade based on MRIO Model

  • Song, Jie;Kim, Yeong-Gil
    • Journal of Korea Trade
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    • v.25 no.2
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    • pp.58-74
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    • 2021
  • Purpose - This paper research on the embodied carbon emission in Sino-Korea trade. It calculates and analyzes the carbon emission coefficient and specific carbon emissions in Sino-Korea trade from 2005 to 2014. Design/methodology - This paper conducted an empirical analysis for embodied carbon emission in Sino-Korea trade during the years 2005-2014, using a multi-region input-output model. First, direct and complete CO2 emission coefficient of the two countries were calculated and compared. On this basis, combined with the world input-output table, the annual import and export volume and sector volume of embodied carbon emission are determined. Then through the comparative analysis of the empirical results, the reasons for the carbon imbalance in Sino-Korea trade are clarified, and the corresponding suggestions are put forward according to the environmental protection policies being implemented by the two countries. Findings - The results show that South Korea is in the state of net trade export and net embodied carbon import. The carbon emission coefficient of most sectors in South Korea is lower than that of China. However, the reduction of carbon emission coefficient in China is significantly faster than that in South Korea in this decade. The change of Korea's complete CO2 emission coefficient shows that policy factors have a great impact on environmental protection. The proportion of intra industry trade between China and South Korea is relatively large and concentrated in mechanical and electrical products, chemical products, etc. These sectors generally have large carbon emissions, which need to be noticed by both countries. Originality/value - To the best knowledge of the authors, this study is the first attempt to research the embodied carbon emission of ten consecutive years in Sino-Korea Trade. In addition, In this paper, some mathematical methods are used to overcome the error problem caused by different statistical caliber in different databases. Finally, the accurate measurement of carbon level in bilateral trade will provide some reference for trade development and environmental protection.

Improving the Professional Competence of a Specialist in Poland by Implementing Multimedia Technologies

  • Kravchenko, Tetiana;Varga, Lesia;Lypchanko-Kovachyk, Oksana;Chinchoy, Alexander;Yevtushenko, Nataliia;Syladii, Ivan;Kuchai, Oleksandr
    • International Journal of Computer Science & Network Security
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    • v.22 no.9
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    • pp.51-58
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    • 2022
  • The article emphasizes the features of the modern education system in Poland, reveals the peculiarities of improving the professional competence of a specialist in Poland through the implementation of multimedia technologies. Various forms of innovations implemented in improving the professional competence of a specialist are listed: improvement (rationalization), modernization, innovation. The forms of professional improvement through the introduction of computer technologies in general and multimedia technologies, in particular, primarily include various professional courses, qualification, preparatory, methodological conferences, seminars, postgraduate studies, foreign and state internships. At the same time, the main direction is self-education. The subject of professional improvement in the application of computer technologies by specialists is the updating of existing knowledge, exchange of professional experience, planning, as well as discussion of innovative works in which specialists participate. Professional growth of specialists can occur both during work and in higher education institutions during their studies. Modernization of computer technologies, especially multimedia ones, is a necessary condition for the functioning of specialists in modern society, since specialists are at the center of the educational process, during the improvement of professional competence. The main functions of the educational process necessary for improving the professional competence of specialists through the implementation of multimedia technologies are revealed. These functions not only contribute to the professional improvement of specialists, but also affect their solutions and optimize the maintenance of contacts between specialists. The importance of creating conditions that are consistent with the modern needs of innovative education is emphasized.

Genetic algorithm-based geometric and reinforcement limits for cost effective design of RC cantilever retaining walls

  • Mansoor Shakeel;Rizwan Azam;Muhammad R. Riaz
    • Structural Engineering and Mechanics
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    • v.86 no.3
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    • pp.337-348
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    • 2023
  • The optimization of reinforced concrete (RC) cantilever retaining walls is a complex problem and requires the use of advanced techniques like metaheuristic algorithms. For this purpose, an optimization model must first be developed, which involves mathematical complications, multidisciplinary knowledge, and programming skills. This task has proven to be too arduous and has halted the mainstream acceptance of optimization. Therefore, it is necessary to unravel the complications of optimization into an easily applicable form. Currently, the most commonly used method for designing retaining walls is by following the proportioning limits provided by the ACI handbook. However, these limits, derived manually, are not verified by any optimization technique. There is a need to validate or modify these limits, using optimization algorithms to consider them as optimal limits. Therefore, this study aims to propose updated proportioning limits for the economical design of a RC cantilever retaining wall through a comprehensive parametric investigation using the genetic algorithm (GA). Multiple simulations are run to examine various design parameters, and trends are drawn to determine effective ranges. The optimal limits are derived for 5 geometric and 3 reinforcement variables and validated by comparison with their predecessor, ACI's preliminary proportioning limits. The results indicate close proximity between the optimized and code-provided ranges; however, the use of optimal limits can lead to additional cost optimization. Modifications to achieve further optimization are also discussed. Besides the geometric variables, other design parameters not covered by the ACI building code, like reinforcement ratios, bar diameters, and material strengths, and their effects on cost optimization, are also discussed. The findings of this investigation can be used by experienced engineers to refine their designs, without delving into the complexities of optimization.

Exploring Data Categories and Algorithm Types for Elementary AI Education (초등 인공지능 교육을 위한 데이터 범주와 알고리즘 종류 탐색)

  • Shim, Jaekwoun
    • 한국정보교육학회:학술대회논문집
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    • 2021.08a
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    • pp.167-173
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    • 2021
  • The purpose of this study is to discuss the types of algorithms and data categories in AI education for elementary school students. The study surveyed 11 pre-elementary teachers after providing education and practice on various data, artificial intelligence algorithm, and AI education platform for 15 weeks. The categories of data and algorithms considering the elementary school level, and educational tools were presented, and their suitability was analyzed. Through the questionnaire, it was concluded that it is most suitable for the teacher to select and preprocess data in advance according to the purpose of the class, and the classification and prediction algorithms are suitable for elementary AI education. In addition, it was confirmed that Entry is most suitable as an AI educational tool, and materials that explain mathematical knowledge are needed to educate the concept of learning of AI. This study is meaningful in that it specifically presents the categories of algorithms and data with in AI education for elementary school students, and analyzes the need for related mathematics education and appropriate AI educational tools.

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A Study on the Jewelry decorative pattern based on Wa-Dang in Unified Silla period (통일신라시대 와당을 모티브로 한 주얼리장식용 문양 연구)

  • kyeng-Tae Kim
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.6
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    • pp.113-122
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    • 2023
  • This study was conducted on the premise of the development of cultural products using relic assets of traditional culture in a knowledge and information society led by culture and soft power. It was conducted in the context of exploring the possibility of cultural content products of Wa-Dang relics excavated from traditional architecture in the Unified Silla Period and expanding the scalability of commercialization motifs that are highly useful in jewelry design. First, the original form, material, use, size, meaning, and formative aesthetics of Wa-Dang were identified through literature and media research. Among the considered Wa-Dang, 10 types of Wa-Dang which represent the category and have values in modules and patterns were selected, and, then, circular images were extracted and modularized with a "formal simplification technique." Based on the "mathematical symmetry analysis technique," which is a method of systematizing pattern composition arrangement format. we derived a planar formative element that can be used in the development of the cultural content industry and jewelry design. In order to expand its usability in the jewelry industry in the future, it was presented as a 2D digital image. In the future, we hope more studies on the various cultural content industry utilizing the traditional culture will be carried out.

Mathematics and Society in Koryo and Chosun (고려.조선시대의 수학과 사회)

  • Joung Ji-Ho
    • The Mathematical Education
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    • v.24 no.2
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    • pp.48-73
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    • 1986
  • Though the tradition of Korean mathematics since the ancient time up to the 'Enlightenment Period' in the late 19th century had been under the influence of the Chinese mathematics, it strove to develop its own independent of Chinese. However, the fact that it couldn't succeed to form the independent Korean mathematics in spite of many chances under the reign of Kings Sejong, Youngjo, and Joungjo was mainly due to the use of Chinese characters by Koreans. Han-gul (Korean characters) invented by King Sejong had not been used widely as it was called and despised Un-mun and Koreans still used Chinese characters as the only 'true letters' (Jin-suh). The correlation between characters and culture was such that, if Koreans used Han-gul as their official letters, we may have different picture of Korean mathematics. It is quite interesting to note that the mathematics in the 'Enlightenment Period' changed rather smoothly into the Western mathematics at the time when Han-gul was used officially with Chinese characters. In Koryo, the mathematics existed only as a part of the Confucian refinement, not as the object of sincere study. The mathematics in Koryo inherited that of the Unified Shilla without any remarkable development of its own, and the mathematicians were the Inner Officials isolated from the outside world who maintained their positions as specialists amid the turbulence of political changes. They formed a kind of Guild, their posts becoming patrimony. The mathematics in Koryo significant in that they paved the way for that of Chosun through a few books of mathematics such as 'Sanhak-Kyemong', 'Yanghwi-Sanpup' and 'Sangmyung-Sanpup'. King Sejong was quite phenomenal in his policy of promotion of mathematics. King himself was deeply interested in the study, createing an atmosphere in which all the high ranking officials and scholars highly valued mathematics. The sudden development of mathematic culture was mainly due to the personality and capacity of king who took anyone with the mathematic talent into government service regardless of his birth and against the strong opposition of the conservative officials. However, King's view of mathematics never resulted in the true development of mathematics perse and he used it only as an official technique in the tradition way. Korean mathematics in King Sejong's reign was based upon both the natural philosophy in China and the unique geo-political reality of Korean peninsula. The reason why the mathematic culture failed to develop continually against those social background was that the mathematicians were not allowed to play the vital role in that culture, they being only the instrument for the personality or politics of the king. While the learned scholar class sometimes played the important role for the development of the mathematic culture, they often as not became an adamant barrier to it. As the society in Chosun needed the function of mathematics acutely, the mathematicians formed the settled class called Jung-in (Middle-Man). Jung-in was a unique class in Chosun and we can't find its equivalent in China or Japan. These Jung-in mathematician officials lacked tendency to publish their study, since their society was strictly exclusive and their knowledge was very limited. Though they were relatively low class, these mathematicians played very important role in Chosun society. In 'Sil-Hak (the Practical Learning) period' which began in the late 16th century, especially in the reigns of Kings Youngjo and Jungjo, which was called the Renaissance of Chosun, the ambitious policy for the development of science and technology called for. the rapid increase of he number of such technocrats as mathematics, astronomy and medicine. Amid these social changes, the Jung-in mathematicians inevitably became quite ambitious and proud. They tried to explore deeply into mathematics perse beyond the narrow limit of knowledge required for their office. Thus, in this period the mathematics developed rapidly, undergoing very important changes. The characteristic features of the mathematics in this period were: Jung-in mathematicians' active study an publication, the mathematic studies by the renowned scholars of Sil-Hak, joint works by these two classes, their approach to the Western mathematics and their effort to develop Korean mathematics. Toward the 'Enlightenment Period' in the late 19th century, the Western mathematics experienced great difficulty to take its roots in the Peninsula which had been under the strong influence of Confucian ideology and traditional Korean mathematic system. However, with King Kojong's ordinance in 1895, the traditional Korean mathematics influenced by Chinese disappeared from the history of Korean mathematics, as the school system was hanged into the Western style and the Western mathematics was adopted as the only mathematics to be taught at the Schools of various levels. Thus the 'Enlightenment Period' is the period in which Korean mathematics shifted from Chinese into European.

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