• Title/Summary/Keyword: Dynamic Elements

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Trends in research on mathematical models for Yin-Yang and the Five Elements (음양오행의 수리모델 연구동향)

  • KIM Sang-beom;CHA Wung-seok;KIM Hee-joon
    • The Journal of Korean Medical History
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    • v.36 no.1
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    • pp.73-88
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    • 2023
  • This article examines the trend of research on mathematical modeling of Yin-Yang and the Five Elements. Through the search engine Google and the library search service of Kyung Hee University, papers that mathematically studied the Yin-Yang Five Elements were searched. Among them, 7 cases published in academic journals were selected and briefly mentioned in the table. And we introduced specific details about four of them. The model format expressing the five elements as a nonlinear system of differential equations was discussed and evaluated.

An Analysis on Incident Cases of Dynamic Positioning Vessels (Dynamic Positioning 선박들의 사고사례 분석)

  • Chae, Chong-Ju;Jung, Yun-Chul
    • Journal of Navigation and Port Research
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    • v.39 no.3
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    • pp.149-156
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    • 2015
  • The Dynamic Positioning System consists of 7 elements which are namely Power system, Human machine interface, DP Computer, Position Reference System(PRS), Sensors, Thruster system and DP Operator. Incidents like loss of position(LOP) on DP vessel usually occur due to errors in these 7 elements. The purpose of this study is to find out safety operation method of DP vessel through qualitative and quantitative analyze of DP LOP incidents which are submitted to IMCA every year. The 612 DP LOP incidents submitted from 2001 to 2010 were analyzed to find out the main cause of the incidents and its rate among other causes. Consequently, the highest rate of incidents involving DP elements are PRS errors. DP computer, Power system, Human error and thruster system came next. The PRS has been analyzed and a flowchart was drawn through expert brainstorming. Also, the conditional probability has been analyzed through Bayesian Networks based on this flowchart. Consequentially, the main causes of drive off incidents were DGPS, microwave radar and HPR. Also, this study identified the main causes of DGPS errors through Bayesian Networks. These causes are signal blocked, electric components failure, relative mode error, signal weak or fail.

Smart Dynamic Pricing in Cognitive Radio Systems

  • Vo, Dat
    • Journal of Korea Society of Industrial Information Systems
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    • v.17 no.2
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    • pp.11-18
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    • 2012
  • Smart Dynamic Pricing has been introduced to address the under-utilised network resources problem in mobile telecommunications systems. In this paper, we investigate the applicability of Smart Dynamic Pricing and its signalling models into Cognitive Radio Systems. Cognitive Radio System is defined as one in which cognitive radios are employed to access shared spectrum and/or dynamically allocated spectrum. Network elements, protocols, traffic and control channels, and system architecture are proposed for the implementation of Smart Dynamic Pricing in Cognitive Radio System. It is found that Smart Dynamic Pricing and its signalling models can be applied to Cognitive Radio Systems.

Modeling and Its Modal Analysis for Distributed Parameter Frame Structures using Exact Dynamic Elements (엄밀한 동적 요소를 이용한 프레임 구조물의 모델링 및 모드 해석)

  • 김종욱;홍성욱
    • Journal of KSNVE
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    • v.9 no.5
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    • pp.966-974
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    • 1999
  • This paper introduces modeling and its modal analysis procedure for exact and closed form solution of in-plane vibrations of general Timoshenko frame structures using exact dynamic element method(EDEM). The derivation procedure of the exact system dynamic matrices for Timoshenko beam frames is described. A new modal analysis procedure is also proposed since the conventional modal analysis schemes are not adequate for the proposed, exact system dynamic matrix. The proposed method provides exact modal parameters as well as all kinds of closed form solutions for general frame structures. Two numerical examples are presented for validating and illustrating the proposed method. The numerical study proves that the proposed method is useful for dynamic analysis of frame structures.

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Development of User-defined Components for Dynamic Test of Distance Relay Models Using PSCAD/EMTDC (PSCAD/EMTDC를 이용한 거리계전기 동특성 시험에 관한 컴포넌트 모델 개발)

  • Lee, Hong-Hak;Lee, Tae-Young;Kim, Ho-Pyo;Nho, Jang-Hyun;Kang, Kun-Soo;Jang, Sung-Hoon;Lee, Jae-Wook
    • Proceedings of the KIEE Conference
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    • 2003.11a
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    • pp.242-244
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    • 2003
  • The functional test of protection relays is divided into two kind of test types; the steady-state test and dynamic test. Because the steady-state test is comparatively easy, this test is used to test the characteristics of the relaying elements, operating values, resetting values and etc. using equipment such as Doble. But the dynamic test has to be performed on the test environment with RTDS(real time digital simulator) because of the dynamic characteristics of real protection relays. Therefore, it is not usually easy to perform dynamic test of relays using power system simulation tool based on PC(personal computer) such as PSCAD/EMTDC. This paper discusses how to develop and implement a test model and user-defined components that can be performed dynamic test using PSCAD/EMTDC.

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Development and Applications of Infinite Elements for Dynamic Soil-Structure Interaction Analysis (동적 지반-구조물 상호작용해석을 위한 무한요소법의 개발 및 응용사례)

  • Yun, C.B.;Yang, S.C.;Kim, J.M.;Choi, J.S.;Kim, D.K.;Seo, C.G.;Chang, S.H.;Park, K.L.
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2008.04a
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    • pp.14-19
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    • 2008
  • This paper presents dynamic infinite element formulations which have been developed for soil-structure interaction analysis both in frequency and in time domains by the present authors during the past twenty years. Axisymmetric, 2D and 3D layered half-space soil media were considered in the developments. The displacement shape functions of the infinite elements were established using approximate expressions of analytical solutions in frequency domain to represent the characteristics of multiple waves propagating into the unbounded outer domain of the media. The proposed infinite elements were verified using benchmark examples, which showed that the present formulations are very effective for the soil-structure interaction analysis either in frequency or in time domain. Example applications to actual interaction problems are also given to demonstrate the capability and versatility of the present methodology.

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Dynamic Nonling Analysis Model for Reinforced Concrete Elements Considering Strain Rate Effects under Repeated Loads (변형율속도를 고려한 반복하중을 받는 철근 콘크리트 부재의 동적 비선형 해석모델)

  • 심종성;문일환
    • Magazine of the Korea Concrete Institute
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    • v.2 no.2
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    • pp.73-80
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    • 1990
  • The current analytical techniques for R/C elements under severe dynamic repeated loads, like earth¬quake or impact, have two major problems; one is that the effects of strain rate are not considered and the other one is the current analytical model was developed based on flexural behavior only. This study develops computer software that can idealize the flexural and shear behavior of R/C elements using several parameters and also can consider the effects of strain rate. The analytical results using the developed technique were compared with serveral experimental results and they were generally satisfied.

Static and dynamic analysis of circular beams using explicit stiffness matrix

  • Rezaiee-Pajand, Mohammad;Rajabzadeh-Safaei, Niloofar
    • Structural Engineering and Mechanics
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    • v.60 no.1
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    • pp.111-130
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    • 2016
  • Two new elements with six degrees of freedom are proposed by applying the equilibrium conditions and strain-displacement equations. The first element is formulated for the infinite ratio of beam radius to thickness. In the second one, theory of the thick beam is used. Advantage of these elements is that by utilizing only one element, the exact solution will be obtained. Due to incorporating equilibrium conditions in the presented formulations, both proposed elements gave the precise internal forces. By solving some numerical tests, the high performance of the recommended formulations and also, interaction effects of the bending and axial forces will be demonstrated. While the second element has less error than the first one in thick regimes, the first element can be used for all regimes due to simplicity and good convergence. Based on static responses, it can be deduced that the first element is efficient for all the range of structural characteristics. The free vibration analysis will be performed using the first element. The results of static and dynamic tests show no deficiency, such as, shear and membrane locking and excessive stiff structural behavior.

A Study on Applications of Housing Interior Design Elements according to the Sensibility Type (감성유형에 따른 주거 실내디자인요소 적용방안)

  • Park, Ji-Min;Park, En-Sun
    • Journal of the Korean housing association
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    • v.25 no.3
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    • pp.165-179
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    • 2014
  • The purpose of this study was to draw application elements of housing interior design according to user-oriented sensibility types. The sensibility evaluation experiments were conducted to target the general user 118 people using the sensibility evaluation tool for housing interior space. The results of the analysis were as: To produce the 'cozy' space, the colors and materials giving soft and natural feeling should be used. For the 'practical' space, type of ceiling and window that give the visually open feeling, the user-oriented furniture arrangement that allows using the space efficiently. For the 'cheerful' space, the simple and natural effects should be produced by using closed space that stable. For the 'traditional' space, the natural fishing material having rough texture should be used. For the 'unique' space, the space contained the dynamic feeling by the diagonal or vertical line and the graphic expression in the wall. For the 'congenial' emotional space, basic is the symmetric, stable and simple space. On the other hand, for the material, small size, natural texture or typical and soft materials should be used. For the 'sensuous' space, the dynamic and vertical sense of space should be expressed by the type of ceiling. The most important elements for the space of 'gorgeous' sensibility, is the color.

Performance evaluation of smart prefabricated concrete elements

  • Zonta, Daniele;Pozzi, Matteo;Bursi, Oreste S.
    • Smart Structures and Systems
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    • v.3 no.4
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    • pp.475-494
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    • 2007
  • This paper deals with the development of an innovative distributed construction system based on smart prefabricated concrete elements for the real-time condition assessment of civil infrastructure. So far, two reduced-scale prototypes have been produced, each consisting of a $0.2{\times}0.3{\times}5.6$ m RC beam specifically designed for permanent instrumentation with 8 long-gauge Fiber Optic Sensors (FOS) at the lower edge. The sensing system is Fiber Bragg Grating (FBG)-based and can measure finite displacements both static and dynamic with a sample frequency of 625 Hz per channel. The performance of the system underwent validation in the laboratory. The scope of the experiment was to correlate changes in the dynamic response of the beams with different damage scenarios, using a direct modal strain approach. Each specimen was dynamically characterized in the undamaged state and in various damage conditions, simulating different cracking levels and recurrent deterioration scenarios, including cover spalling and corrosion of the reinforcement. The location and the extent of damage are evaluated by calculating damage indices which take account of changes in frequency and in strain-mode-shapes. The outcomes of the experiment demonstrate how the damage distribution detected by the system is fully compatible with the damage extent appraised by inspection.