• 제목/요약/키워드: physical theory

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주관절 외측상과염 환자에 대한 팔허(八虛) 이론에 근거한 복합침구치료 치험 2례 (Effect of Eight Vacuity Theory Adopted Complex Acupuncture Therapy on Patients with External Epicondylitis)

  • 신대철;이지인;강미숙;송호섭
    • Journal of Acupuncture Research
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    • 제32권2호
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    • pp.209-216
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    • 2015
  • Objectives : The objective of this study was to report two cases that patients with external epicondylitis were improved by based on 'eight vacuity' theory bloodletting therapy, acupuncture therapy and bee venom pharmacopuncture. Methods : In this study, patients were treated with bloodletting therapy, then acupuncture therapy and bee venom pharmacopuncture to Ashi point on eight vacuity of elbow in the patients without retention of needles. Subsequently, electroacupuncture and Dong-qi acupuncture treatment were implemented in order to strengthen the effect of acupuncture. In terms of evaluation methods, visual analog scale(VAS) score, range of motion(ROM), grip strength and physical examination were used to assess external epicondylitis-related symptoms. Results : VAS score decreased, ROM and grip strength were increased and physical examination was improved in all cases. Conclusions : It was suggested that the symptoms of intractable external epicondylitis could be improved by eight vacuity theory adopted bloodletting therapy, acupuncture therapy and bee venom pharmacopuncture.

Hydrodynamic 이론을 이용한 성형작약탄두 제트의 관통 현상에 관한 유한요소 해석 (Finite Element Analysis for the Penetration Phenomena of Shaped Charge Jets using Hydrodynamic Theory)

  • 강영구
    • 한국전산구조공학회논문집
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    • 제32권2호
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    • pp.133-140
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    • 2019
  • 본 논문은 Shaped charge jet(SCJ)의 관통 과정을 유한요소해석을 통해 모사하여 제트 입사속도, 관통률 그리고 관통량 증분과 같은 물리량들을 획득하였다. 이 물리량들을 hydrodynamic 이론에 적용하여 입사 제트 속도의 효율을 분석한 결과, 입사 속도가 빠른 제트의 관통 효율은 이어지는 느린 제트에 비해 높은 것을 확인하였다. 이 효율은 hydrodynamic limit(HL) 미만인 제트인 경우 큰 폭으로 감소하였다. 한편, 시간에 따른 관통량 증분과 제트 소모량의 비교는 SCJ의 이론적인 관통현상 분석을 위해서는 길이 연장 효과를 고려해야함을 보였다.

Application of Fractal Theory to Various Surfaces

  • Roh, Young-Sook;Rhee, In-Kyu
    • International Journal of Concrete Structures and Materials
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    • 제18권1E호
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    • pp.23-28
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    • 2006
  • In this study, the general theory of fractality is discussed to provide a fundamental understanding of fractal geometry applied to heterogeneous material surfaces like pavement surface and rock surface. It is well known that many physical phenomena and systems are chaotic, random and that the features of roughness are found at a wide spectrum of length scales from the length of the sample to the atomic scales. Studying the mechanics of these physical phenomena, it is absolutely necessary to characterize such multi scaled rough surfaces and to know the structural property of such surfaces at all length scales relevant to the phenomenon. This study emphasizes the role of fractal geometry to characterize the roughness of various surfaces. Pavement roughness and rock surface roughness were examined to correlate their roughness property to fractality.

Detecting Crime Hot Spots Using GAM and Local Moran's I

  • Cheong, Jin-Seong
    • International Journal of Contents
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    • 제8권2호
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    • pp.89-96
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    • 2012
  • Scientific analysis of crime hot spots is essential in preventing and/or suppressing crime. However, results could be different depending on the analytic methods, which highlights the importance of choosing adequate tools. The purpose of this study was to introduce two advanced techniques for detecting crime hot spots, GAM and Local Moran's I, hoping for more police agencies to adopt better techniques.GAM controls for the number of population in study regions, but local Moran's I does not. That is, GAM detects high crime rate areas, whereas local Moran's I identifies high crime volume areas. For GAM, physical disorder was used as a proxy measure for population at risk based on the logic of the broken windows theory. Different regions were identified as hot spots. Although GAM is generally regarded as a more advanced method in that it controls for population, it's usage is limited to only point data. Local Moran's I is adequate for zonal data, but suffers from the unavoidable MAUP(Modifiable Areal Unit Problem).

사토(砂土)에 있어서 모델 테스트에 의한 차륜(車輪)의 성능(性能) 예측(豫測)에 관한 연구(硏究) (Performance Prediction of Powered-Rigid Wheel by Model Tests)

  • 이규승;이용국;박승제
    • Journal of Biosystems Engineering
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    • 제13권4호
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    • pp.1-8
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    • 1988
  • A series of soil bin experiments was carried out on land to evaluate the soil physical properties whether they are pertinent to soil-wheel system and to investigate if true model theory u applicable to powered rigid wheel-soil system. Four different sized wheels having diameter of 45, 60, 75 and 90 em were wed for the experiment. The following conclusion was derived from the study. (1) True model theory can be sufficiently utilized to study the wheel traction and linkage on lands. (2) For both dry and wet sands, Cone Index(CI) and soil shear parameters (c, ${\phi}$) with bulk density (${\gamma}$) were found to be good measures of soil physical properties which are pertinent to predict the performance of the powered rigid wheel-soil system.

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System of Systems Approach to Formal Modeling of CPS for Simulation-Based Analysis

  • Lee, Kyou Ho;Hong, Jeong Hee;Kim, Tag Gon
    • ETRI Journal
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    • 제37권1호
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    • pp.175-185
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    • 2015
  • This paper presents a system-of-systems (SoS) approach to the formal modeling of a cyber-physical system (CPS) for simulation-based analysis. The approach is based on a convergence technology for modeling and simulation of a highly complex system in which SoS modeling methodology, hybrid systems modeling theory, and simulation interoperation technology are merged. The methodology maps each constituent system of a CPS to a disparate model of either continuous or discrete types. The theory employs two formalisms for modeling of the two model types with formal specification of interfaces between them. Finally, the technology adapts a simulation bus called DEVS BUS whose protocol synchronizes time and exchange messages between subsystems simulation. Benefits of the approach include reusability of simulation models and environments, and simulation-based analysis of subsystems of a CPS in an inter-relational manner.

광음향효과에 의한 화합물 반도체의 물성연구 (A Study on the Physical Properties of Compound Semiconducts by Photoacoustic Spectroscopy)

  • 윤화중
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 1984년도 추계학술발표회 논문집
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    • pp.27-32
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    • 1984
  • When chopped light inpinges on some condenced matters such as HgS, HgI2 and GaSe semiconductors, in an enclosed cell, the acoustic signals are produced within the cell. These acoustic signals were detected by using a gas-phase microphone in order to investigate the physical properties of the samples. In order to carry out investigation, PA-cell was first designed and made so as to produce higher sensitivity to acoustic signals. Second, an analysis of the photoacoustic spectrum of the various compounds was carried out to obtain the intensity of the PA-signal in terms of light wavelength and to calculate the energy band gaps occuring according to energy transitions. The agreement between the results obtained by this conventional PAS technique and the results obtained by the optical spectrum method was good. In additional analysis conducted on the basis of the R-G theory and the Sze theory are capable of determining the characteristics of energy transition of semiconductors.

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Effect of heat source and gravity on a fractional order fiber reinforced thermoelastic medium

  • Jain, Kavita;Kalkal, Kapil Kumar;Deswal, Sunita
    • Structural Engineering and Mechanics
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    • 제68권2호
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    • pp.215-226
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    • 2018
  • In this article, the theory of fractional order two temperature generalized thermoelasticity is employed to study the wave propagation in a fiber reinforced anisotropic thermoelastic half space in the presence of moving internal heat source. The whole space is assumed to be under the influence of gravity. The surface of the half-space is subjected to an inclined load. Laplace and Fourier transform techniques are employed to solve the problem. Expressions for different field variables in the physical domain are derived by the application of numerical inversion technique. Physical fields are presented graphically to study the effects of gravity and heat source. Effects of time, reinforcement, fractional parameter and inclination of load have also been reported. Results of some earlier workers have been deduced from the present analysis.

전위생성에 대한 이론으로서의 응력파 개념에 대한 제안 및 적용 연구 (Proposal of the Stress Wave Concept and Its Applied Study as a Theory for the Dislocation Formation)

  • 서정현
    • 소성∙가공
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    • 제10권6호
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    • pp.449-456
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    • 2001
  • The concept of stress wave was introduced through the quantized kinetic energy which is related to the potentional energy change of atom, molecular bond energy. Differentiated molecular bond energy $\varphi$() by the lst order displacement u becomes force F(F = d$\varphi$($u_i$)/du), if resversely stated, causing physically atomic displacement $u_i$. Such physical phenomena lead stress(force/area of applied force) can be expressed by wave equation of linearly quantized physical property. Through the stress wave concept, formation of dislocation, which could not explained easily from a theory of continuum mechanics, can be explained. Moreover, this linearly quantized stress wave equation with a stress concept for grains in a crystalline solid was applied to three typical metallic microstructures and a simple shape. The result appears to be a product from well treated equations of a quantized stress wave. From this result, it can be expected to answer the reason why the defect free and very fine diameters of long crystalline shapes exhibit ideal tensile strength of materials.

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Analytical solution of a two-dimensional thermoelastic problem subjected to laser pulse

  • Abbas, Ibrahim A.;Alzahrani, Faris S.
    • Steel and Composite Structures
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    • 제21권4호
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    • pp.791-803
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    • 2016
  • In this article, the problem of a two-dimensional thermoelastic half-space are studied using mathematical methods under the purview of the generalized thermoelastic theory with one relaxation time is studied. The surface of the half-space is taken to be thermally insulated and traction free. Accordingly, the variations of physical quantities due to by laser pulse given by the heat input. The nonhomogeneous governing equations have been written in the form of a vector-matrix differential equation, which is then solved by the eigenvalue approach. The analytical solutions are obtained for the temperature, the components of displacement and stresses. The resulting quantities are depicted graphically for different values of thermal relaxation time. The result provides a motivation to investigate the effect of the thermal relaxation time on the physical quantities.