• Title/Summary/Keyword: size guide

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A Study on Safety Management Development Plan of Domestic City Gas Facility (국내 도시가스 시설의 안전관리 발전방안에 관한 연구)

  • 정원익;양광모;강경식
    • Journal of the Korea Safety Management & Science
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    • v.6 no.2
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    • pp.23-33
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    • 2004
  • Domestic city gas is supplying in an about 10 million household on present 34 city gas companies because is begun to supply regularly after two 1980 years middle. But, result that focus on city gas supply spread and stable supply for supply area and neglects about safety problem, hundreds casualties such as Ahyun explosion accident and Deagu city gas explosion accident were reached in situation that occurred large size calamity occurs it is dizzliness. In the case of advanced nation, can see that accomplish system and progress that in technology after experience major accident. Therefore, grasp problem investigating safety actual conditions for city gas institution and study about solvable plan is required this. Also, must guide reform and level elevation of a domestic company safety technology through induction and development of safety technology that is suitable in supply, domestic real condition etc. Must help in power positivity that is full text executing high-quality safety education about step High firing mechanism safety technology than present safety education.

Application of Piezoceramic Actuator to the Inch-Worm (이송자벌레로의 압전세라믹 작동기 응용)

  • Kim, In-Su;Lee, Hong-Sik;Song, Jun-Yeop
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.8
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    • pp.157-163
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    • 2001
  • This paper presents the new linear notion device so called \"inch-werm\" which gets large displacement by incrementally summing small displacements of PZT actuators. Dynamic stiffness of inch-worm is generally low compared to its driving condition due to the requirement of inch-worm like small size and light weight. This low stiffness may degenerate the positional precision of inch-worm. An inch-worm is realized using three PZT actuators, a monolithic moving device and a guide way frame. Finite element method and experimental approach are used to analyse the static and dynamic motion of the designed inch-worm. Command reference input is shaped to reduce the residual vibration of inch-worm. The practical feasibility of inch-worm is also examined by running tests.ing tests.

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Optimum Design of a Cross Flow Fan (횡류팬의 최적설계방안)

  • Kim Dong-Hoon;Park Hyung-Koo
    • Journal of computational fluids engineering
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    • v.8 no.4
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    • pp.50-57
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    • 2003
  • Cross-flow fans are widely used in various applications, due to their large capacity of mass flow and size compactness. The flow field of the cross-flow fan is, however, complex and has many design parameters. Thus, the general design guide has not been sufficiently established yet and the design strategies of cross-flow fans have been mostly based on experiments. In the present study, the performance and their two-dimensional flow characteristics are numerically analyzed by using the STAR-CD(commercial computational fluid dynamics code). The simulation is done by varying the several design parameters such as the impeller blade shapes and the gap between the stabilizer and impeller. The computational results are compared with the experimental data at the fan outlet region. Finally, some helpful guides for the optimum design of cross-flow fans are proposed.

Design and Analysis of A Mini Linear Optical Pickup Actuator

  • Park, Joon-Hyuk;Baek, Yoon-Su;Park, Young-Pil
    • Journal of Mechanical Science and Technology
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    • v.17 no.11
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    • pp.1616-1627
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    • 2003
  • This paper describes a mini linear optical pickup actuator. To reduce the size, inner yokes are designed to guide the mover and outer yokes of permanent magnets are removed. Magnetic circuit method is used to determine the thrust force. Virtual path method is proposed to analyze the open magnetic circuit analysis. The magnetic circuit of the proposed actuator can be a closed circuit due to the virtual path model of the outer magnetic flux. The validity of virtual path method is evaluated by comparing to the FEM analysis. Structural vibration is investigated using FEM and the design of the mover is modified to improve the vibration characteristic. Dynamic characteristic experiments shows that the performance of the proposed actuator is enough to be used as a coarse and fine seeking actuator simultaneously and the thrust force margin for loading a focusing actuator is guaranteed.

Vibration Analysis of Separation Screen for a Recycling of Construction Wastes (건설폐기물의 재활용을 위한 분리스크린의 진동해석)

  • Kim, K.K.;Kim, M.S.;Son, K.;Kim, K.H.;Moon, B.Y.
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1057-1062
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    • 2007
  • The purpose of this study is to find out design parameters of vibrating screen, such as particles motion, specific gravity, shape, and kinetic friction. In order to approach this problem, four materials of construction wastes, wood, styrofoam, concrete, and sand are used for dynamic modeling. To present friction between the particles material and tilt plates material, these particles model is applied in order to verify effectively. Generally, the vibrating screen is composed of three assemblies such as screen, wastes guide, supported of screen. This model regards vibrator as system of screen fixed tilt plates. The model is analyzed to present what kind of particles motion while the system is vibrating. and this vibration system has been implemented in a ADAMS dynamaic program. This modeling is consist of dynamic model separation state on particle size. This study make good technique to verify in theory.

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A Study on the Analysis of Pogo Stability of Liquid Propellant Rocket (액체추진로켓의 포고 안정성 해석에 관한 연구)

  • 장홍석;연정흠;윤성기;정태규
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2002.04a
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    • pp.10-13
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    • 2002
  • Pogo is the instability resulting from the interaction between rocket structure and propulsion system of liquid propellant rocket. The coupling of structure and propulsion system can lead to severe problem in rocket. For the analysis of pogo, a time-invariant linearized mathematical model is developed for a selected flight time. Propulsion system is modeled using element representations for each components. The constitutive equation of propulsion system is a homogeneous second-order equation form in the Laplace domain. Rocket structure is modeled using FEM. From the results of modal analysis of structure, the behavior of structure can be represented. System equations for coupling structure and propulsion system are composed of all propulsion system equations and vehicle motion equations reacting on the vehicle by each component of propulsion system. The stability is obtained by the eigen solution of system matrix. The optimization of the design variables such as size, place of accumulator for suppressing pogo instability is carried out. This article of study can be used to determine the degree of stability, and guide the design of pogo suppression system.

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Application of Piezoceramic Actuator for Inch-Worm (이송 자벌레로의 압전소자 응용)

  • 윤재헌;채재희;김인수
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.877-880
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    • 2001
  • This paper presents the new linear motion device so called "inch-worm" which gets large displacement by incrementally summing small displacements of PZT actuators. Dynamics stiffness of inch-worm is generally low compared to its driving condition due to the requirement of inch-worm like small size and light weight. This low stiffness may degenerate the positional precision of inch-worm. An inch-worm is realized using three PZT actuators, a monolithic moving device and a guide way frame. Driving input signal is shaped to reduce the residual vibration of inch-worm by LQG controller and cycloid step input. The practical feasibility of inch-worm is also examined by running test.ning test.

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Extreme baking effect of interlayer on PLED's performance

  • Kim, Mu-Gyeom;Kim, Sang-Yeol;Lee, Tae-Woo;Park, Sang-Hun;Park, Jong-Jin;Pu, Lyong-Sun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1775-1778
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    • 2006
  • Through baking process on an interlayer, known as hole transporting layer, varying baking temperature up to 300 degree, which is considered as extremely high for polymer light emitting device (PLED) system, we found interesting relationship between packing density and morphology affecting device performance. Granular morphology shows that as temperature increases, grain size is getting smaller to pack closely and make interlayer harden. Such denser interlayer has temperature dependency of its own mobility, even without clear evidence of degradation of material itself. Its fact proven in a single film also reflects on multilayered PLED's performance like IVL, efficiency, lifetime. It's found that, especially, to enhance lifetime is related with thermal stability of interlayer and its mobility dependency to meet better charge balance. Therefore, it gives us understanding not only baking effect of interlayer, but also material & device designing guide to enhance lifetime.

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The optimum simulation and real test of double prismatic Light-guide plate for a high brightness LCD backlight unit

  • Yoon, D.K.;Park, D.S.;Oh, Y.S.;Bae, K.W.;Kim, K.H.;Lim, Y.J.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1503-1506
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    • 2005
  • This dissertation represents method concerning high performance prism LGP design in 17 inch TFT-LCD. By means of developing LGP with total size of 8mm that has prism on both upper side and bottom side, it is superior to previous printing way in gaining high brightness. It can realize actual material simulation on prism LGP production using 17inch injection process and about 20% luminance enhancement is achieved based on such method.

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Optimum Design of a Cross Flow Fan

  • Kim Dong-Hoon;Park Hyung-Koo
    • 한국전산유체공학회:학술대회논문집
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    • 2003.10a
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    • pp.260-262
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    • 2003
  • Cross-flow fans are widely used in various applications, due to their large capacity of mass flow and size compactness. The flow field of the cross-flow fan is, however, complex and has many design parameters. Thus, the general design guide has not been sufficiently established yet and the design strategies of cross-flow fans have been based on experiments. In the present study, the performance and their two-dimensional flow characteristics are numerically analyzed by using the STAR-CD(commercial computational fluid dynamics code). The simulation is done by varying the several design parameters such as the impeller blade shapes and the gap between the stabilizer and impeller. The computational results are compared with the experimental data at the fan outlet region. Finally some helpful guides for the optimum design of cross-flow fans are proposed.

  • PDF