• 제목/요약/키워드: superposition principle

검색결과 102건 처리시간 0.021초

과학과 상상력의 중첩성 (The superposition of Science and Imagination)

  • 홍명희
    • 비교문화연구
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    • 제34권
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    • pp.93-114
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    • 2014
  • Gaston Bachelard had a revolutionary progress in the field of human understanding by proposing his theory of image and imagination. His theory of the new image was so powerful, almost all areas of human science, particularly that of literary criticism, were strongly influenced and this influence continues until today. Today almost everyone accepts his theory of the image without much objection, but not rarely asked where began his transfer from the philosophy of science to the images. We propose a hypothesis that the beginning of the new concept of Bachelard's image was inspired by studies of contemporary science, especially quantum mechanics. The Heisenberg's uncertainty principle was the core of quantum mechanics, and opens new perspectives on the material world. We could summarize the message of the uncertainty principle : the material world is made up of various layers, and the material can not be measured by the location and movement at the same time. So we must have a new point of view of another dimension to know this material world. Bachelard had accepted this view of Heisenberg and developed his own theory of epistemological rupture. What is revolutionary in the theory of Bachelard's image is the fact that he looked at the images with the new perspective. The human psyche is another world compared to the rational world that dominates our daily lives. Bachelard insists that the image can not be explained by the concept. The fantasy world is a totally different world to that of rationality. That is why it can not be explained by the language of rationality as the concept. The imaginary world exists independently of the real world, but it is superimposed on the real world. These two worlds are influencing each other, and it is between these two world where our daily lives continues. The declaration of Bachelard 'image is a specific reality' is never a metaphor or rhetorical expression. This is an ontological expression that must truthfully. The imaginary world is a world built on the image and it works according to its own law. It is not a representation or copy of the real world. But the world of imagination are not alone. It exists in the same time and space with the world of science. It is superimposed with the world of science. Both two world influence each other. Bachelard has made a revolutionary change by studying the images. He gave them their own place. It has changed the views on the images that were treated as mere representations of reality. Thanks to him, the image can have its own value, that of a factor that creates reality. Bachelard shows how we can go deep into the source of being and the universe if we look at the pictures with the eyes of other dimensions.

Flexural behavior of beams in steel plate shear walls

  • Qin, Ying;Lu, Jin-Yu;Huang, Li-Cheng-Xi;Cao, Shi
    • Steel and Composite Structures
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    • 제23권4호
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    • pp.473-481
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    • 2017
  • Steel plate shear wall (SPSW) system has been increasingly used for lateral loads resisting system since 1980s when the utilization of post-buckling strength of SPSW was realized. The structural response of SPSWs largely depends on the behavior of the surrounded beams. The beams are normally required to behave in the elastic region when the SPSW fully buckled and formed the tension field action. However, most modern design codes do not specify how this requirement can be achieved. This paper presents theoretical investigation and design procedures of manually calculating the plastic flexural capacity of the beams of SPSWs and can be considered as an extension to the previous work by Qu and Bruneau (2011). The reduction in the plastic flexural capacity of beam was considered to account for the presence of shear stress that was altered towards flanges at the boundary region, which can be explained by Saint-Venant's principle. The reduction in beam web was introduced and modified based on the research by Qu and Bruneau (2011), while the shear stress in the web in this research is excluded due to the boundary effect. The plastic flexural capacity of the beams is given by the superposition of the contributions from the flanges and the web. The developed equations are capable of predicting the plastic moment of the beams subjected to combined shear force, axial force, bending moment, and tension fields induced by yielded infill panels. Good agreement was found between the theoretical results and the data from previous research for flexural capacity of beams.

Life Time Prediction Using Accelerated Ageing Test for a CR/CB Rubber Composite

  • Ahn, WonSool;Lee, Hyung Seok
    • Elastomers and Composites
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    • 제52권4호
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    • pp.237-241
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    • 2017
  • The tensile strength (TS) and elongation-at-break (EB) loss of a CR/CB rubber composite sample prepared for the automotive parts were measured after accelerated thermal ageing at temperatures of 100, 120, 140, and $150^{\circ}C$. The change in TS was observed to be linear from the master curve prepared using the time-temperature superposition-principle (TTSP). An Arrhenius type of shift factor, $a_T$ was used to predict the life time of the sample, and a plot of ln $a_T$ vs. 1/T was also shown to be linear. The activation energy ($E_a$) of the sample was calculated as 70.30 kJ/mole from the Arrhenius plot. The expected life time of the sample was predicted at the given operating conditions by applying Arrhenius analysis. Assuming the $E_a$ value was constant at lower operating condition, life time of the sample was calculated as 2.3 years when the life limit was set as time to reach the 20% decrease of the initial TS value at operating temperature of $40^{\circ}C$.

모바일 역할수행 게임의 시간 기반 재구조화 (Time-based Restructuring of Mobile Roleplaying Games)

  • 이진
    • 한국게임학회 논문지
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    • 제17권5호
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    • pp.39-50
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    • 2017
  • 본고는 모바일 미디어의 이동성을 중심으로 모바일 게임 플랫폼의 개념과 게임하기의 변화를 살피고, 모바일 매개의 시간 변수를 통해 재구조화된 모바일 게임의 텍스트를 역할수행 게임을 중심으로 분석한다. 이동하는 존재로서 플레이어는 모바일 미디어를 통해 게임 플랫폼과 결합한다. 모바일 미디를 통해 매개된 일상의 시간은 중첩된 시간으로 재구성되며, 모바일 게임 플랫폼에서 플레이에 영향을 미친다. 모바일 역할수행 게임의 캐릭터는 사건을 경험하는 아바타가 아닌 플레이어가 머무르는 플레이 거점이 되며, 이는 거주의 공간이 아닌 이동 중 거주의 공간으로서 비장소적 특성을 가진다. 자동전투는 비경험한 전투를 명시적 통합체의 형태로 반복 재생한다. 중첩된 시간에서 전투의 경험은 시각적 스펙터클로서 기능하며, 플레이어로 하여금 기경험한 전투들을 환기시킨다.

Aerodynamic stability analysis of geometrically nonlinear orthotropic membrane structure with hyperbolic paraboloid in sag direction

  • Xu, Yun-ping;Zheng, Zhou-lian;Liu, Chang-jiang;Wu, Kui;Song, Wei-ju
    • Wind and Structures
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    • 제26권6호
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    • pp.355-367
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    • 2018
  • This paper studies the aerodynamic stability of a tensioned, geometrically nonlinear orthotropic membrane structure with hyperbolic paraboloid in sag direction. Considering flow separation, the wind field around membrane structure is simulated as the superposition of a uniform flow and a continuous vortex layer. By the potential flow theory in fluid mechanics and the thin airfoil theory in aerodynamics, aerodynamic pressure acting on membrane surface can be determined. And based on the large amplitude theory of membrane and D'Alembert's principle, interaction governing equations of wind-structure are established. Then, under the circumstance of single-mode response, the Bubnov-Galerkin approximate method is applied to transform the complicated interaction governing equations into a system of second-order nonlinear differential equation with constant coefficients. Through judging the frequency characteristic of the system characteristic equation, the critical velocity of divergence instability is determined. Different parameter analysis shows that the orthotropy, geometrical nonlinearity and scantling of structure is significant for preventing destructive aerodynamic instability in membrane structures. Compared to the model without considering flow separation, it's basically consistent about the divergence instability regularities in the flow separation model.

Behavior of polygonal concrete-filled steel tubular stub columns under axial loading

  • Zhang, Tao;Ding, Fa-xing;Wang, Liping;Liu, Xue-mei;Jiang, Guo-shuai
    • Steel and Composite Structures
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    • 제28권5호
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    • pp.573-588
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    • 2018
  • The objective of this paper is to investigate the mechanical performances of polygonal concrete-filled circular steel tubular (CFT) stub columns under axial loading through combined experimental and numerical study. A total of 32 specimens were designed to investigate the effect of the concrete strength and steel ratio on the compressive behavior of polygonal CFT stub columns. The ultimate bearing capacity, ductility and confinement effect were analyzed based on the experimental results and the failure modes were discussed in detail. Besides, ABAQUS was adopted to establish the three dimensional FE model. The composite action between the core concrete and steel tube was further discussed and clarified. It was found that the behavior of CFT stub column changes with the change of the cross-section, and the change is continuous. Finally, based on both experimental and numerical results, a unified formula was developed to estimate the ultimate bearing capacity of polygonal CFT stub columns according to the superposition principle with rational simplification. The predicted results showed satisfactory agreement with both experimental and FE results.

스트럿-타이 모델에 의한 콘크리트 T형 교각 코핑부의 설계 (Design of RC T-type Pier Coping Using Strut-and-Tie Model)

  • 정광회;심별;송하원;변근주
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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    • pp.617-622
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    • 2000
  • In this study, effective compressive strength and nodal zone of Strut-and-Tie Model are studied to propose a new design method for RC T-type pier coping for prevention of sudden brittle failure. The coping which transmits loads of bridge to pier should be properly designed to retain ductile behavior. In order to carry out this proper design using STM, tie must yield before concrete fails, and a stress at strut should not exceed a certain effective stress. Therefore, reasonable determination of the effective compressive strength of strut by considering stress states at the nodal zone exactly is very important. Since conventional STM is applied under assumption that all nodes are under hydrostatic stress state, actual non-hydrostatic stress state in nodal zone caused by geometrical characteristics, loading conditions, support conditions of structures can not be considered properly. In order to apply STM for design of RC T-type pier coping, the non-hydrostatic stress state of nodal zone is considered and effective compressive strength is proposed. Then, a new design method of RC T-type pier coping which applies the principle of superposition to obtain optimum ductile behavior is rationally designed.

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Seismic behavior of T-shaped steel reinforced high strength concrete short-limb shear walls under low cyclic reversed loading

  • Chen, Zongping;Xu, Jinjun;Chen, Yuliang;Su, Yisheng
    • Structural Engineering and Mechanics
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    • 제57권4호
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    • pp.681-701
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    • 2016
  • This paper presents an experimental study of six steel reinforced high strength concrete T-shaped short-limb shear walls configured with T-shaped steel truss under low cyclic reversed loading. Considering different categories of ratios of wall limb height to thickness, shear/span ratios, axial compression ratios and stirrup reinforcement ratios were selected to investigate the seismic behavior (strength, stiffness, energy dissipation capacity, ductility and deformation characteristics) of all the specimens. Two different failure modes were observed during the tests, including the flexural-shear failure for specimens with large shear/span ratio and the shear-diagonal compressive failure for specimens with small shear/span ratio. On the basis of requirement of Chinese seismic code, the deformation performance for all the specimens could not meet the level of 'three' fortification goals. Recommendations for improving the structural deformation capacity of T-shaped steel reinforced high strength concrete short-limb shear wall were proposed. Based on the experimental observations, the mechanical analysis models for concrete cracking strength and shear strength were derived using the equivalence principle and superposition theory, respectively. As a result, the proposed method in this paper was verified by the test results, and the experimental results agreed well with the proposed model.

Improved Method for Calculating Magnetic Field of Surface-Mounted Permanent Magnet Machines Accounting for Slots and Eccentric Magnet Pole

  • Zhou, Yu;Li, Huaishu;Wang, Wei;Cao, Qing;Zhou, Shi
    • Journal of Electrical Engineering and Technology
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    • 제10권3호
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    • pp.1025-1034
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    • 2015
  • This paper presented an improved analytical method for calculating the open-circuit magnetic field in the surface-mounted permanent magnet machines accounting for slots and eccentric magnet pole. Magnetic field produced by radial and parallel permanent magnet is equivalent to that produced by surface current according to equivalent surface-current method of permanent magnet. The model is divided into two types of subdomains. The field solution of each subdomain is obtained by applying the interface and boundary conditions. The magnet field produced by equivalent surface current is superposed according to superposition principle of vector potential. The investigation shows harmonic contents of radial flux density can be reduced a lot by changing eccentric distance of eccentric magnet poles compared with conventional surface-mounted permanent-magnet machines with concentric magnet poles. The FE(finite element) results confirm the validity of the analytical results with the proposed model.

초음파 측정법에 의한 아스팔트 세멘트의 점탄성 특성 평가 (Viscoelastic Property Evaluation of Asphalt Cement by Ultrasonic Measurement)

  • 이재학
    • 비파괴검사학회지
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    • 제20권5호
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    • pp.402-411
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    • 2000
  • 이 연구에서는 점탄성 재료중의 하나인 아스팔트 세멘트의 점탄성 특성을 초음파를 이용하여 측정하는 방법에 대하여 고찰하였다. 2.25MHz의 주파수에서 $-20^{\circ}C$부터 $60^{\circ}C$까지의 온도변화에 따른 파속도와 감쇠를 측정한 후, 선형 점탄성 이론에 근거하여 저장 및 손실 종탄성율, 손실 탄젠트, 저장 및 손실 종컴플라이언스와 같은 물성변화를 구하였다. Maxwell과 Voigt-Kelvin 점탄성 모델을 이용하여 응력완화 및 크리프 거동과 점도의 변화도 예측하였다. 또한 중첩원리와 이동인자의 타당성을 문헌에 보고된 결과와 비교함으로써 입증할 수 있었다.

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