• Title/Summary/Keyword: conservation law

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A Study on the Land Use Control and Compensation Plan for Jeju Island Coastal Landscape Conservation (제주도 해안경관보전을 위한 토지이용규제와 보상방안에 관한 연구)

  • Lee, Jin-Hee
    • Journal of Korean Society of Rural Planning
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    • v.12 no.3 s.32
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    • pp.29-37
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    • 2006
  • Jeju coastal landscape has been changed from 1980's. Construction of coastal road, rearing fm, restaurant and condominium are main reasons of destroying the Jeju coastal area. Recently, the law for preserving coastal landscape is effective to prevent diverse construction activities, the land is comparatively restricted in the coastal landscape preservation districts. The resident's attitude toward restricted landlord has been carried out in Jeju province and compensation program has been developed for landlord in the coastal landscape preservation district. To speak compensation programs, First, land compensation as if cash compensation and right of purchase claim, Second, incentive as if tax reducement or regional support, Third, assignment of development right.

Theoretical Analysis of Steady State Low Current Arcs in Dual Flow Nozzles

  • Song, K.D.;Shin, Y.J.;Lee, H.S.;Kim, K.S.
    • Proceedings of the KIEE Conference
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    • 1992.07b
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    • pp.952-957
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    • 1992
  • When the circuit-breaker switches off, an electric arc is established between the contacts. It is very important to understand the arc characteristics for the design of a circuit breaker. This article describes the theoretical analysis of the arc characteristics by means of energy integral method when convection dominated low current arcs are produced in the dual-airflow nozzle of a model interrupter. In order to investigate the arc radius, the average electric field strength and the arc voltage, the arc column is divided into two regions, and then the energy conservation equation is applied to the arc in each region together with the axial cold flow mass flux function, steady-state mass balance equation and Ohm's law. The results show good agreements with those of other researchers.

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Comparing Two Approaches of Analyzing Mixed Finite Volume Methods

  • Chou, So-Hsiang;Tang, Shengrong
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.5 no.1
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    • pp.55-78
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    • 2001
  • Given the anisotropic Poisson equation $-{\nabla}{\cdot}{\mathcal{K}}{\nabla}p=f$, one can convert it into a system of two first order PDEs: the Darcy law for the flux $u=-{\mathcal{K}{\nabla}p$ and conservation of mass ${\nabla}{\cdot}u=f$. A very natural mixed finite volume method for this system is to seek the pressure in the nonconforming P1 space and the Darcy velocity in the lowest order Raviart-Thomas space. The equations for these variables are obtained by integrating the two first order systems over the triangular volumes. In this paper we show that such a method is really a standard finite element method with local recovery of the flux in disguise. As a consequence, we compare two approaches in analyzing finite volume methods (FVM) and shed light on the proper way of analyzing non co-volume type of FVM. Numerical results for Dirichlet and Neumann problems are included.

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Numerical flow computation around aeroelastic 3D square cylinder using inflow turbulence

  • Kataoka, Hiroto;Mizuno, Minoru
    • Wind and Structures
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    • v.5 no.2_3_4
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    • pp.379-392
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    • 2002
  • Numerical flow computations around an aeroelastic 3D square cylinder immersed in the turbulent boundary layer are shown. Present computational code can be characterized by three numerical aspects which are 1) the method of artificial compressibility is adopted for the incompressible flow computations, 2) the domain decomposition technique is used to get better grid point distributions, and 3) to achieve the conservation law both in time and space when the flow is computed a with moving and transformed grid, the time derivatives of metrics are evaluated using the time-and-space volume. To provide time-dependant inflow boundary conditions satisfying prescribed time-averaged velocity profiles, a convenient way for generating inflow turbulence is proposed. The square cylinder is modeled as a 4-lumped-mass system and it vibrates with two-degree of freedom of heaving motion. Those blocks which surround the cylinder are deformed according to the cylinder's motion. Vigorous oscillations occur as the vortex shedding frequency approaches cylinder's natural frequencies.

Biomimetic Balancing Mechanism for Walking Robot (생체모사를 통한 보행로봇의 균형감에 관한 연구)

  • Kim, Jong Jin;Chung, Seong Youb
    • Journal of Institute of Convergence Technology
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    • v.4 no.2
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    • pp.55-59
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    • 2014
  • A cat is able to quickly recover balance from unstable posture. To observe the balance recovery procedure of the cat, an impulse is applied to the cat while walking on a narrow bridge. We find that it rotates its tail toward the falling direction. In our previous research, the balance recovery procedure is analyzed based on the law of the angular momentum conservation and then a key equation is derived to maintain the balance. However, it did not consider the gravity, so the performance is not good. In this paper, a new dynamic model is proposed using the Lagrangian mechanics. In the method, the gravity is included in the potential energy. Through the proposed dynamic model, controlling the balance of a walking robot is possible.

Path Planning of a Free Flying Object and its Application for Gymnastic Robots

  • Nam Taek-Kun;Kim Yong-Joo
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.5B no.1
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    • pp.63-69
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    • 2005
  • The motion of animals and gymnasts in the air as well as free flying space robots without thrusters are subjected to nonholonomic constraints generated by the law of conservation of angular momentum. The purpose of this paper is to derive analytical posture control laws for free flying objects in the air. We propose the bang-bang control method for trajectory planning of a 3 link mechanical system with initial angular momentum. This technique is used to reduce the DOF (degrees of freedom) at first switching phase and to determine the control inputs to steer the reduced order system to the desired position. Computer simulations for motion planning of an athlete approximated by 3 link, namely platform diving, are provided to verify the effectiveness of the proposed control scheme.

A Study on the Type classification of Urban Architectural Assets - Focused on the Modern Architecture in Daegu Seosungro - (도시건축자산의 유형분류에 대한 연구 -대구시 서성로의 근대건축물을 중심으로-)

  • Do, Hyun-Hak
    • Journal of the Korean Institute of Rural Architecture
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    • v.17 no.1
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    • pp.45-54
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    • 2015
  • This study is about the Type classification of architectural assets in Seosungro (one of the 4 Roads of Rampart in Junggu, Daegu), the main stronghold of Urban Regeneration projects according to the recent Urban Regeneration law. The purpose of this study is to suggest the basic data about Operation management method of Original Downtown modern buildings and valuable hanok, and Conservational Regeneration of Architectural property of Urban Environmental Improvement and Architectural assets. By researching, analysing the feature and classifying the type of the buildings in Seosungro, The type classified Conservation plan can be suggested. The Types of the Architectural assets will be the basic data of the application plan of modern buildings which is for the urban regeneration, and this can predict the quantity and the demand of the building for effective urban regeneration, and also can be an effective Urban regeneration policy data.

Performance Analysis for CO2 System with Sub-cooling loop (과냉 회로를 갖는 이산화탄소 냉동시스템에 대한 성능 해석)

  • Kim, Jin-Man;Ko, Sung-Gyu;Kim, Moo-Geun
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.6
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    • pp.723-728
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    • 2007
  • In order to evaluate the performance of carbon dioxide cycle with a sub-cooling loop. a simulation system was developed to predict the steady state of $CO_2$ trans-critical cycle. Mathematical models are derived to describe the relationships between the system's coefficient of performance and other operating parameters The mathematical models are based entirely on the basic mass and energy conservation law and thermodynamic and transport properties of carbon dioxide A parametric study has been conducted in order to investigate the effect of sub-cooling loop and various operating conditions on the cycle performance. An optimal mass fraction of a refrigerant flowing through sub-cooling cycle existed for the given evaporating temperature, high pressure and air inlet temperature through gas cooler.

Numerical study on in-cylinder flow of a reciprocating engine using a fractional step method (Fractional step method를 이용한 엔진내부유동의 수치해석)

  • Lee, Byoung-Seo;Kong, Ho-Jin;Lee, Joon-Sik;Yoo, Jung-Yul
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.745-750
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    • 2000
  • A numerical code which can simulate unsteady, incompressible and 3-dimensional flows in an engine cylinder has been developed. The governing equations based on the cylindrical coordinate are discretized by the finite volume method with staggered variable arrangements. A geometric conservation rule is also incorporated into the simulation code in order to deal with a moving boundary problem. For the unsteady simulation, a fractional step method is adopted. The law of wall is applied to the wall boundaries and standard $k-\;{\varepsilon}$ model is used to describe the in-cylinder turbulent flow. The model cylinder has one eccentric port, flat piston and flat cylinder-head. The comparisons with experimental data show fairly well qualitative agreement.

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A Study on the 3-D Unsteady State Heat Transfer Coupled by Conductive Currents (전기장 변화에 따른 3차원 비정상 상태 열전달 연계 해석에 관한 연구)

  • Kwac, L.K.;Kim, H.G.
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.1
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    • pp.29-34
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    • 2008
  • A modeling technique for the 2-way coupling of heat transfer and conduction currents has been performed to inspire a combined analytical simulation. The 3-D finite element method is used to solve steady conduction currents and heat generation in an aluminum film deposited on a silicon substrate. The model investigates the temperature in the device after the current is applied. The conservation equation of energy, the Maxwell equations for conduction currents, the unsteady state heat transfer equation and the Fourier's law for heat transfer are implemented as a bidirectionally coupled problem. It is found that the strongly coupled temperature and time dependent heat equations give a reasonable results and an explicit solving technique.