3,881 research outputs found

    Analysis of the Behavior of a Penetrator Advancing Through a Guide Surface

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    The study concerns the transverse deformation behavior of a penetrator surrounded by sabot in a deformed gun barrel. In the gun barrel, transverse deformation occurs in the penetrator due to problems such as deflection by gravity, or geometric tolerance caused by the manufacturing process. This deformation causes structural instability problems and affects out-of-gun barrel movement. In addition, the deformation and structural safety of the penetrator is affected by the sabot supporting the penetrator. The finite element method was used to evaluate the effect of the sabot. Deformation and stress analysis were performed for the penetrator moving in the gun barrel, and the effect of the elastic modulus of the sabot on the deformation of the penetrator was studied

    The 1911 Revolution and the Korean Independence Movement: The Road to Democratic Republicanism

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    Identification of parameter matrices using estimated FRF variation

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    This study presents an analytical method to predict the dynamic parameters of actual structure from measured FRF (Frequency Response Function) data. The inconsistency due to modeling errors between the actual structure and the finite element model exists. The number of measured data is less than the one of a full set of dofs and should be expanded to estimate the parameters. Considering that the stiffness and mass matrices are related with the real part of the expanded FRF data and the damping matrix with the imaginary part, the variation in the parameter matrices is evaluated. A numerical example evaluates the appropriateness of the proposed method

    Damage detection based on the internal force or deformation variation

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    The presence of damage in an intact structure leads to the change in internal force and deformation due to stiffness deterioration in the region of damage. This study proposes modelbased damage detection methods by deriving the mathematical formulation to describe such changes. The force and deformation variations between the undamaged and damaged systems are derived by minimizing the variation in dynamic strain energy with respect to the internal force and deformation vectors, respectively. They are expressed by the product of a coefficient matrix and the external force vector, and the product of a coefficient matrix and the displacement vector, respectively. Taking singular value decomposition (SVD) on the coefficient matrices of rank-deficiency, this study identifies the damaged elements as belonging to the set of elements whose internal forces or deformations between two adjacent nodes of finite element model are not changed. The validity of the proposed methods is illustrated in a simple application

    Solution structure and p43 binding of the p38 leucine zipper motif: coiled-coil interactions mediate the association between p38 and p43

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    Abstractp38, which has been suggested to be a scaffold protein for the assembly of a macromolecular tRNA synthetase complex, contains a leucine zipper-like motif. To understand the importance of the leucine zipper-like motif of p38 (p38LZ) in macromolecular assembly, the p38LZ solution structure was investigated by circular dichroism and nuclear magnetic resonance spectroscopy. The solution structure of p38LZ showed an amphipathic α-helical structure and characteristics similar to a coiled-coil motif. The protein–protein interaction mediated by p38LZ was examined by an in vitro binding assay. The p43 protein, another non-synthetase component of the complex, could bind to p38LZ via its N-terminal domain, which is also predicted to have a potential coiled-coil motif. Thus, we propose that the p38–p43 complex would be formed by coiled-coil interactions, and the formation of the binary complex would facilitate the macromolecular assembly of aminoacyl-tRNA synthetases
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