• Title/Summary/Keyword: Modeling step

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2-Step Modeling for Daily Load Curve of Up to and Including 100kVA Distribution Transformer (100kVA 이하급 배전용 변압기 일부하 패턴의 2-Step 모델링)

  • Lee, Young-Suk;Kim, Jae-Chul;Yun, Sang-Yun
    • Proceedings of the KIEE Conference
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    • 2001.11b
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    • pp.371-373
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    • 2001
  • In this paper, we present 2-step load cycle for daily load curve of up to and including 100kVA distribution transformer in domestic. Daily load patterns are classified by two methods dependent upon possession information. In case we possess daily load profiles make use of K-mean algorithm and in case we have not daily load profiles, make use of customer information of KEPCO. As the parameters of the load pattern classification, we use are daily load profiles and customer information of each distribution transformers. Data management system is used for NT oracle. We can present peak load magnitude, initial load magnitude and peak load duration for daily load patterns by 2-step load cycle for daily load curve of up to and including 100kVA distribution transformer in domestic. We think that this paper contributes to enhancing the distribution transformer overload criterion.

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Modeling And Analysis of Torque Characteristics for Full-step of 4Phase And 5Phase Hybrid Type Step Motors (4상과 5상 스텝모터의 모델링 및 구동방식에 따른 토크특성해석)

  • Choi, D.S.;Baek, S.H.;Kim, Y.;Yun, S.Y.;Kim, C.J.;Lim, T.B.
    • Proceedings of the KIEE Conference
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    • 1998.11a
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    • pp.37-39
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    • 1998
  • The hybrid step motor has found applications in a wide range of mechanical systems as a low cost, open-loop positioning device. The step motor provides good stiffness at rest against disturbing load influences, a combination of moderate speed fine resolution, high reliability and simplicity. In recent years, considerable competition has arisen over the technological issue of wheather the device should be applied as a 2-Phase or 5-Phase machine. In this paper, to compare two systems, we have atempted to derive the mathematical. model, and analysed operating detent torque with this model. The analysis shows that a fundamental component of the permeance distribution produces the average torque and that harmonic components produce the ripple torque.

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An analysis on risk factor of constructor with Fuzzy-FMEA (Fuzzy-FMEA를 활용한 시공사의 리스크 요인 분석)

  • Kim, Seok Cheol
    • Journal of the Korea Safety Management & Science
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    • v.19 no.4
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    • pp.43-52
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    • 2017
  • The purposes of this study are to analyze risks of construction step BIM(Building Information Modeling) applied project and improve it. Recently, construction industry has emphasized an importance of BIM for efficient utilization of various information. In the whole life cycle of huge construction project, there are cases introducing BIM and projects applying BIM are gradually increased to the work of construction step. However, the process of communication is not established, so the contents of BIM process of construction step are just showing rough fields and concepts of working utilization, so it's restrictive to utilize BIM actively on constructions step. Through results of case study in this research, constructor risks of BIM business should be efficiently treated with Fuzzy-FMEA that is more precise than existing danger evaluation.

Modeling, Simulation, and Control of a Polyaniline/Carbon-Nanotube Polymer Actuator (폴리아닐린/탄소나노튜브 폴리머 액츄에이터의 모델링, 시뮬레이션 및 제어)

  • Sohn, Ki-Won;Yi, Byung-Ju;Kim, Sean-Jeong;Kim, In-Young;Kim, Sun-I.
    • Journal of Biomedical Engineering Research
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    • v.28 no.3
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    • pp.348-354
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    • 2007
  • Polymer actuators, which are also called as smart materials, change their shapes when electrical, chemical, thermal, or magnetic energy is applied to them and are useful in wide variety of applications such as microelectromechanical systems (MEMS), machine components, and artificial muscles. For this study, Polyaniline/carbon-nanotube polymer actuator that is one of electroactive polymer actuators was prepared. Since the nonlinear phenomena of hysteresis and a step response are essential considerations for practical use of polymer actuators, we have investigated the movement of the Polyaniline/carbon-nanotube polymer actuator and have developed an integrated model that can be used for simulating and predicting the hysteresis and a step response during actuation. The Preisach hysteresis model, one of the most popular phenomenological models of hysteresis, were used for describing the hysteretic behavior of Polyaniline/carbon-nanotube polymer actuator while the ARX method, one of system identification techniques, were used for modeling a step response. In this paper, we first expain details in preparation of the Polyaniline/carbon-nanotube polymer then present the mathematical description of our model, the extraction of the parameters, simulation results from the model, and finally a comparison with measured data.

A study on the integrative feedback modeling to develop pre-service teachers' competence of planning STEAM lessons (예비교사의 융합적 수업구성 역량 향상을 위한 통합적 피드백의 모델링)

  • Hong, Ye-Yoon;Im, Yeon-Wook
    • Journal of Digital Convergence
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    • v.19 no.8
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    • pp.75-88
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    • 2021
  • Along with the advent of the Fourth Industrial Revolution, fostering young talents with convergent mind is getting important. Moreover pre-service teachers' ability to design proper convergent classes can be a meaningful issue for high quality future education. This study proposes the role of professors' exquisite feedback is so significant for developing their competence in STEAM education, It analyzed how various theories regarding feedback support them to enhance convergent knowledge with e-learning. They participated in the 5 step group and individual activities for creating STEAM lesson plan and received suitable feedback. Lastly a survey was performed. The researchers did modeling how integrative feedback was applied to the procedure step by step according to the 'Ladder of Inference' theory. This strategic model contributed to elevating the participants' convergent knowledge, competence, achievement and satisfaction.

Dynamic hybrid position/force controller for two cooperating robots (두 협동로보트를 위한 동력학 Hybrid 위치/힘 제어기)

  • 이남구;김종수;박종국
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.327-331
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    • 1992
  • In this paper, we propose dynamic hybrid control method which takes the manipulator dynamics into consideration and extend to two cooperating robots. The first step is the linearization of the manipulator dynamics and the second step is the design of position/force controllers for the linearized model which takes account of both the command response and the robustness of the controllers to modeling errors and disturbance. We also consider load sharing for each robot.

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Construction of a Knowledge Based Hybrid Simulation Environment

  • Kim, Myoung-Hee
    • Journal of the Korea Society for Simulation
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    • v.1 no.1
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    • pp.25-30
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    • 1992
  • A knowledge based hybrid simulation environment has been established which supports the simulation procedure from the modeling step to the experimentation step by providing various tools, query, and advisory. The knowledge base in the established environment uses the If-Then Rule to transfer the fact input from the user to the act for the execution of the simulation process. Simulation non-experts are the user target and non-specific area is the application target.

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A Study of Formation & Application of step-wise level curriculum of Mathematics (수학과 단계형 수준별 교육과정 편성.운영에 관한 연구)

  • 최택영;함석돈
    • The Mathematical Education
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    • v.40 no.2
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    • pp.179-194
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    • 2001
  • The seventh curriculum put into operation gradually from first-year student in 2000 academic years of elementary school is subject to form and apply a step-wise level curriculum. Mathematics(correspond to junior high school course from 7th school year to 9th school year) should apply a step-wise level curriculum from 7th school year in 2001 academic years. Accordingly, mathematics teachers must diagnose actual conditions of educations, distribution tables of test results, step-wise teaching-studying programs etc. They also make proper plans suitable for actual situations of each school, prepare appropriate teaching materials and aids. I investigated preceding studies planned for preparation of putting into operation of a step-wise level curriculum. It showed that most of the studies were conducted at schools of medium or large scale and studies conducted at schools of small scale was rare. There were 113 small scale middle schools out of total 297 middle schools in Kyongsangbuk-do area in 2000. In this situation, I felt necessities of modeling of a step-wise level curriculum suitable for small scale schools. In this study, I modeled a step-wise level curriculum suitable for small scale middle schools, applied this model to 44 students in M middle school. I modeled two types of curriculum. One is a step-wise level curriculum that execute special supplementation process to students who do not complete 7-가 step successfully. The other is a step-wise level curriculum which is a regular model for a step-wise level of 7-나 step. I carried out an academic achievement test and intimacy test about mathematics before and after the application of the model. In this study, I found out that this model was very effective in academic achievement of students and helpful to declined students in scholarship. In the intimacy test, It was found out that most of the students gained confidence in mathematics, felt less anxiety, formed positive self consciousness. Therefore, I think that this model will be helpful to the application of the seventh step-wise level curriculum.

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Semantic Visualization of Dynamic Topic Modeling (다이내믹 토픽 모델링의 의미적 시각화 방법론)

  • Yeon, Jinwook;Boo, Hyunkyung;Kim, Namgyu
    • Journal of Intelligence and Information Systems
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    • v.28 no.1
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    • pp.131-154
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    • 2022
  • Recently, researches on unstructured data analysis have been actively conducted with the development of information and communication technology. In particular, topic modeling is a representative technique for discovering core topics from massive text data. In the early stages of topic modeling, most studies focused only on topic discovery. As the topic modeling field matured, studies on the change of the topic according to the change of time began to be carried out. Accordingly, interest in dynamic topic modeling that handle changes in keywords constituting the topic is also increasing. Dynamic topic modeling identifies major topics from the data of the initial period and manages the change and flow of topics in a way that utilizes topic information of the previous period to derive further topics in subsequent periods. However, it is very difficult to understand and interpret the results of dynamic topic modeling. The results of traditional dynamic topic modeling simply reveal changes in keywords and their rankings. However, this information is insufficient to represent how the meaning of the topic has changed. Therefore, in this study, we propose a method to visualize topics by period by reflecting the meaning of keywords in each topic. In addition, we propose a method that can intuitively interpret changes in topics and relationships between or among topics. The detailed method of visualizing topics by period is as follows. In the first step, dynamic topic modeling is implemented to derive the top keywords of each period and their weight from text data. In the second step, we derive vectors of top keywords of each topic from the pre-trained word embedding model. Then, we perform dimension reduction for the extracted vectors. Then, we formulate a semantic vector of each topic by calculating weight sum of keywords in each vector using topic weight of each keyword. In the third step, we visualize the semantic vector of each topic using matplotlib, and analyze the relationship between or among the topics based on the visualized result. The change of topic can be interpreted in the following manners. From the result of dynamic topic modeling, we identify rising top 5 keywords and descending top 5 keywords for each period to show the change of the topic. Existing many topic visualization studies usually visualize keywords of each topic, but our approach proposed in this study differs from previous studies in that it attempts to visualize each topic itself. To evaluate the practical applicability of the proposed methodology, we performed an experiment on 1,847 abstracts of artificial intelligence-related papers. The experiment was performed by dividing abstracts of artificial intelligence-related papers into three periods (2016-2017, 2018-2019, 2020-2021). We selected seven topics based on the consistency score, and utilized the pre-trained word embedding model of Word2vec trained with 'Wikipedia', an Internet encyclopedia. Based on the proposed methodology, we generated a semantic vector for each topic. Through this, by reflecting the meaning of keywords, we visualized and interpreted the themes by period. Through these experiments, we confirmed that the rising and descending of the topic weight of a keyword can be usefully used to interpret the semantic change of the corresponding topic and to grasp the relationship among topics. In this study, to overcome the limitations of dynamic topic modeling results, we used word embedding and dimension reduction techniques to visualize topics by era. The results of this study are meaningful in that they broadened the scope of topic understanding through the visualization of dynamic topic modeling results. In addition, the academic contribution can be acknowledged in that it laid the foundation for follow-up studies using various word embeddings and dimensionality reduction techniques to improve the performance of the proposed methodology.

Fuzzy Neural Network with Rule Generaton Nased on Back-Propagation Algorithm (학습기능을 갖는 자동 규칙 생성 퍼지 신경망)

  • 정재경;이동윤;정기욱;김완찬
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.4
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    • pp.191-200
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    • 1996
  • This paper presetns a new fuzzy neural network for fuzzy modeling.The fuzzy neural network is composed of 4 layers and then odes of each layer represent the each step of the if-then fuzzy inference. A heuristic based on the back-propagation algorithm is proposed to ajdust the parameters of the fuzzy nerual network. We prove the feasibility of the network using the experiments on modeling a nonlinear mathematical system and the comparison with previous research.

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