• Title/Summary/Keyword: Physical Element

Search Result 1,126, Processing Time 0.024 seconds

Studies on Physical Properties of Wood-based Composite Panel with Recycled Tire Chip - Change of Properties on Composite Panel by Mixing Ratio of Combined Materials - (폐타이어를 이용한 목질고무 복합패널의 물성에 관한 연구 - 원료혼합비율에 따른 복합패널의 재질변화 -)

  • Lee, Weon-Hee;Byeon, Hee-Seop;Bae, Hyun-Mi
    • Journal of the Korean Wood Science and Technology
    • /
    • v.26 no.1
    • /
    • pp.70-75
    • /
    • 1998
  • In this paper, the relationships between volumetric mixing ratio of rubber chip and physical and mechanical properties of wood/rubber composite panel was examined in order to investigate the mixture characteristics of wood and rubber chip. Because of the specific gravity of rubber differed from wood chip, physical properties of wood/rubber composite panel was shown very different values by mixing rate of chip element. Specific gravity in air-dry of composite panel was increased rapidly as volumetric percent of rubber chip was increased. Moisture content of composite panel was decreased as volumetric percent of rubber chip element was increased. This results was considered that wood weight is light and porosity material for moisture absorption. Compressive strength and modulus of rupture in bending test were decreased as volumetric percent of rubber chip increased. By mixing ratio control of chip elements, various wood/rubber composite panel can be applicable to every interior materials such as subfloor, playground, and exterior materials such as road blocks for recreational facilities in garden and forest and city parks.

  • PDF

Enhanced Approach Using Computational and Experimental Method for the Analysis of Loudspeaker System

  • Park Seok-Tae
    • The Journal of the Acoustical Society of Korea
    • /
    • v.24 no.3E
    • /
    • pp.90-98
    • /
    • 2005
  • Enhanced approach using computational and experimental method is proposed and performed to describe very well the behavior of loudspeaker than conventional method. Proposed procedure is composed of four parts. First, Thiele-Small parameters for test loudspeaker are identified by an electrical impedance method like as a delta mass method. Second part includes the processes to measure physical properties. Physical data like masses and thicknesses of loudspeaker's components are measured by an electrical precision scale and a digital vernier caliper. Third, the identified Thiele-Small parameters are proposed to be used as load boundary conditions for vibration analysis instead of electromagnetic circuit analysis to get a driving force upon bobbin part. Also, these parameters and physical data are used to modify physical properties required for computation to accommodate simulated sound pressure level with measured one for loudspeaker enclosure system. These data like as Young's modulus and thickness for a diaphragm are required for vibration analysis of loudspeaker but not measured accurately. Finally, it was investigated that simulated sound pressure level with full acoustic modeling including an acoustic port for test loudspeaker agreed with experimental result very well in the midrange frequency band(from 100 Hz to 2,000 Hz). In addition, several design parametric study is performed to grasp acoustical behaviors of loudspeaker system due to variations of diaphragm thicknesses and shapes of dust cap.

phenomenological representation of nature in Display (디스플레이에 있어서 자연과 현상)

  • 임진이
    • Korean Institute of Interior Design Journal
    • /
    • no.27
    • /
    • pp.145-151
    • /
    • 2001
  • There is so much difference in the way we perceive nature whether from eastern or western, present or past standpoint. however, awareness of coexistence between human beings and nature along with the concept that the most natural is th e most beautiful remain unchanged. The desire to describe the beauty of nature have existed all through the ages, but the (new) naturalism movement was spawned in our time when so much devastation and side effects took place for the expediency of nature, and field of display has been trying new interpretation of nature with direct or applied method. Naturalism trend is studied using the categories such as relationship between human and nature, space concept in western and eastern society, and the definition of view of nature in modern time. Elements of naturalism display are classified into the element of physical properties and element beyond the physical properties, and then methodology on naturalism display is investigated, using the illustration of display examples, in order to know the most essential elements of display, which are the physical properties such as space, light, object, glass, are expressed based on the elemental concept like nature, an accident, dynamic state, variability. As mentioned above, Naturalism display consists of physical properties and phenomenon. How to ive strong impression to a spectator depends on the ability to create effective space applying these elements. The significance of this study comes to surface in a time when the tremendous emphasis is put on the importance of nature and concerns about the role of display has become even greater.

  • PDF

The Finite Element Analysis of Foundation Layer by Introducing Interface Element (접합요소를 도입한 기초지반의 유한요소해석(지반공학))

  • 정진섭;이대재;봉기영
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2000.10a
    • /
    • pp.425-430
    • /
    • 2000
  • In the analysis of deformation in which the stiffness is greatly different between the adjacent materials, the desired results have been obtained by using the interface element method compared with those secured by the conventional method of the concept of continua. This study deals with the deformation analysis of soft foundation by the introduction of interface element. The physical conditions of interface element are divided into three categories by Mohr-Coulomb failure criterion ie. sliding, separation, and contact. Finally the accuracy of the program proposed in this paper is proved highly accurate by performing the comparison of the theoretical values numerical results of a model element with simplified boundary conditions.

  • PDF

Bond Graph Modeling for Piezoelectric Transducers (수중 음향 트랜스듀서 용 압전 소자의 모델링 기법)

  • 문원규
    • Proceedings of the Acoustical Society of Korea Conference
    • /
    • 1998.06e
    • /
    • pp.129-132
    • /
    • 1998
  • A bond graph modeling approach which is equivalent to a finite element method is formulated in the case of the piezoelectric thickness vibrator. This formulation suggests a new definition of the generalized displacements for a continuous system as well as the piezoelectric thickness vibrator. The newly defined coordinates are illustrated to be easily interpreted physically and easily used in analysis of the system performance. The bond graph model offers the primary advantage of physical realizability and has a greater physical accuracy because of the use of multiport energic elements. While results are presented is general in scope and can be applied to arbitrary physical systems.

  • PDF

The studies of actual condition and therapeutic effects of hot spring water in Korea (우리나라 온천의 실태와 치료적 효과에 관한 연구)

  • Park Rae-Joon
    • The Journal of Korean Physical Therapy
    • /
    • v.12 no.3
    • /
    • pp.369-377
    • /
    • 2000
  • Hot spring water is petrifaction water and mixed with animals and plants disintegrated water in the underground. The ingredient are complicated and abundant. The contained element is used to facilitate the function of human body. activate the human structure movement. discharge waste material due to increase circulation and metabolism, also it can remain the homeostasis. We can not find research for spa therapy in our country. We use to drink and bath in the hot spring water bue don't have rehabilitation facilities

  • PDF

A Qualitative Case Study Research of Application of Saam Five Element Acupuncture in Psychiatry -the Field Study of a Clinic- (사암침법의 정신과적 활용에 대한 질적 사례연구 -한 의료기관에 대한 현장연구-)

  • Suh, Hyo-Weon;Lee, Jung Hwan;Kwak, Hui-Yong;Chung, Sun-Yong;Kim, Jong Woo
    • Journal of Oriental Neuropsychiatry
    • /
    • v.29 no.3
    • /
    • pp.183-195
    • /
    • 2018
  • Objectives: To investigate validity and effectiveness of Saam five element acupuncture treatment in psychological problems. Methods: We selected a Korean medicine doctor known to apply Saam five element acupuncture treatment to the psychiatry field. An investigator visited the doctor's clinic to observe the cases and interview patients. Duration of each interview was 30 minutes to one hour. A semi-structured questionnaire was used for in-depth interviews. All interviews were recorded and converted into texts. Converted texts were then summarized and analyzed qualitatively. Results and Discussion: Treatment process of Saam five element acupuncture designed for psychiatric use is divided into four stages: qi transformation (氣化), acupuncture treatment, deep breathing, and acupressure. In the first stage, patients are asked to express their feelings and emotions in a physical sense; to imagine their feelings have colors, weight, and physical form, and to describe those characteristics. Next, the doctor evaluates each patient's qi according to the six qi (六氣), and then determines protocol of Saam five element acupuncture treatment. This treatment is focused on suffering of the patient and specific symptoms or emotions. The treatment duration is brief and changes in symptoms are frequently checked during treatment sessions. Without discussing details of stressful events, the doctor enables patients to express physical aspects of their feelings. He also provides them with psychoeducational resources. As a result, patients experienced immediate changes in body sensation, emotions and thinking, decreased response to triggers, and increased self-control after treatment. Conclusions: The Saam five element acupuncture treatment has the potential to be used as a treatment for psychiatric disorders. Treatment can be effective in managing psychiatric disorders when applied by primary Korean medicine clinics.

Real-Time Hybrid Testing Using a Fixed Iteration Implicit HHT Time Integration Method for a Reinforced Concrete Frame (고정반복법에 의한 암시적 HHT 시간적분법을 이용한 철근콘크리트 골조구조물의 실시간 하이브리드실험)

  • Kang, Dae-Hung;Kim, Sung-Il
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.15 no.5
    • /
    • pp.11-24
    • /
    • 2011
  • A real-time hybrid test of a 3 story-3 bay reinforced concrete frame which is divided into numerical and physical substructure models under uniaxial earthquake excitation was run using a fixed iteration implicit HHT time integration method. The first story inner non-ductile column was selected as the physical substructure model, and uniaxial earthquake excitation was applied to the numerical model until the specimen failed due to severe damage. A finite-element analysis program, Mercury, was newly developed and optimized for a real-time hybrid test. The drift ratio based on the top horizontal displacement of the physical substructure model was compared with the result of a numerical simulation by OpenSees and the result of a shaking table test. The experiment in this paper is one of the most complex real-time hybrid tests, and the description of the hardware, algorithm and models is presented in detail. If there is an improvement in the numerical model, the evaluation of the tangent stiffness matrix of the physical substructure model in the finite element analysis program and better software to reduce the computational time of the element state determination for the force-based beam-column element, then the comparison with the results of the real-time hybrid test and the shaking table test deserves to make a recommendation. In addition, for the goal of a "Numerical simulation of the complex structures under dynamic loading", the real time hybrid test has enough merit as an alternative to dynamic experiments of large and complex structures.

Development of FE Analysis Scheme for Milli-Part Forming Using Grain Element (유한요소법의 입자요소를 이용한 박판 성형해석)

  • 구태완;강범수
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2003.05a
    • /
    • pp.439-442
    • /
    • 2003
  • This study presents a new computational model to analyze the grain deformation in a polycrystalline aggregate in a discrete manner and based directly in the underlying physical micro-mechanisms. As a result, specific characteristics have to be considered for the numerical analysis. The grains and grain boundary elements are introduced to model individual grains and grain boundary facets, respectively, to consider the size effects in the micro forming. The constitutive description of the grain elements accounts for the rigid-plastic and the grain boundary elements for elastic relationships. The capability of the proposed approach is demonstrated through application of grain element and grain boundary element in the micro forming.

  • PDF

Development of FE Analysis Scheme for Milli-Part Forming Using Grain and Grain Boundary Element (입자요소를 이용한 미세 박판 부품의 유한요소 해석 기법 개발)

  • 구태완;김동진;강범수
    • Transactions of Materials Processing
    • /
    • v.11 no.5
    • /
    • pp.439-446
    • /
    • 2002
  • This study presents a new computational model to analyze the grain deformation in a polycrystalline aggregate in a discrete manner and based directly in the underlying physical micro-mechanisms. When scaling down a metal forming process, the dimensions of the workpiece decrease but the microstructure of the workpiece remains the similar. Since the dimensions of the workpiece are very small, the microstructure especially the grain size will play an important role in micro forming, which is called size effects. As a result, specific characteristics have to be considered for the numerical analysis. The grains and grain boundary elements are introduced to model individual grains and grain boundary facets, respectively, to consider the size effects in the micro forming. The constitutive description of the grain elements accounts for the rigid-plastic and the grain boundary elements for visco-elastic relationships. The capability of the proposed approach is demonstrated through application of grain element and grain boundary element in the micro forming.