• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.54.1-54
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• 2001

In this paper, an alternate method for state-covariance assignment for SISO(single input singe output) linear systems is proposed. This method is based on the inverse solution of the Lyapunov matrix equation and the resulting formulas are similar in structure to the formulas for pole placement. Further, the set of all assignable covariance matrices to a SISO linear system is also characterized.

• Bulletin of the Korean Chemical Society
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• v.17 no.9
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• pp.836-839
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• 1996

A new copper complex containing 2,2'-dipyridylbenzamide(dpba), Cu(dpba)(NO3)2(CH3CN), has been synthesized and characterized. The crystal structure has been determined. Crystal data: space group P212121, Z=8, a=13.911(3) Å, b=16.813(3) Å, c=18.932(3) Å, V=4427.9(1) Å3 and R=0.0674 for 1716 reflections. The copper environment is square pyramidal containing acetonitrile in axial site. Spectroscopic properties has been characterized in solution state. The redox property of the Cu(dpba)(NO3)2 complex is different from that of corresponding copper-dpa complex.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.12
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• pp.1208-1211
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• 2010

We propose a variable structure control design method for a class of multivariable uncertain state-delayed systems which can be represented by polytopic models. In terms of LMIs, we derive a sufficient condition for the existence of a linear sliding surface guaranteeing the asymptotic stability of the sliding mode dynamics. We parameterize the sliding surface by using the solution of the LMI existence condition. We also give a switching feedback control strategy guaranteeing stable sliding mode. By using a numerical example, we show that our method supplements the existing results and it can be better than the existing results.

• Structural Engineering and Mechanics
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• v.56 no.6
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• pp.983-1001
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• 2015

This study focuses on the load carrying capacity and the force transfer mechanism of multi-hole perfobond shear connectors in steel-concrete composite structure. The behavior of multi-hole perfobond shear connector is more complicated than single-hole connector cases. 2 groups push-out tests were conducted. Based on the test results, behavior of the connection was analyzed and the failure mechanism was identified. Simplified iterative method and analytic solution were proposed based on force equilibrium for analyzing multi-hole perfobond shear connector performance. Finally, the sensitivity of design parameters of multi-hole perfobond shear connector was investigated. The results of this research showed that shear force distribution curve of multi-hole perfobond shear connector is near catenary. Shear forces distribution were determined by stiffness ratio of steel to concrete member, stiffness ratio of shear connector to steel member, and number of row. Efficiency coefficient was proposed to should be taking into account in different limit state.

• Journal of Mechanical Science and Technology
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• v.15 no.11
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• pp.1507-1516
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• 2001

An analytical method is presented for evaluation of the steady state periodic behavior of nonlinear structural systems. This method is based on the substructure synthesis formulation and a harmonic balance procedure, which is applied to the analysis of nonlinear responses. A complex nonlinear system is divided into substructures, of which equations are approximately transformed to modal coordinates including nonlinear term under the reasonable procedure. Then, the equations are synthesized into the overall system and the nonlinear solution for the system is obtained. Based on the harmonic balance method, the proposed procedure reduces the size of large degrees-of-freedom problem in the solving nonlinear equations. Feasibility and advantages of the proposed method are illustrated using the study of the nonlinear rotating machine system as a large mechanical structure system. Results obtained are reported to be an efficient approach with respect to nonlinear response prediction when compared with other conventional methods.

• Structural Engineering and Mechanics
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• v.83 no.6
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• pp.729-744
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• 2022

In this paper, an analytical formulation is proposed to predict the vertical vibration response due to the pedestrian walking on a footbridge considering the human-structure interaction, where the footbridge and pedestrian are represented by the Euler beam and linear oscillator model, respectively. The derived coupled equation of motion is a nonlinear fourth-order partial differential equation. An uncoupled solution strategy based on the combined weighted residual and perturbation method) is proposed to reduce the tedious computation, which allows the separate integration between the bridge and pedestrian subsystems. The theoretical study demonstrates that the pedestrian subsystem can be treated as a structural system with added mass, damping, and stiffness. The analysis procedure is then applied to a case study under the conditions of single pedestrian and multi pedestrians, and the results are validated and compared numerically. For convenient vibration design of a footbridge, the simplified peak acceleration formula and the idea of decoupling problem are thus proposed.

• BMB Reports
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• v.35 no.2
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• pp.143-154
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• 2002

The structural and functional aspects of ervatamin B were studied in solution. Ervatamin B belongs to the $\alpha+\beta$ class of proteins. The intrinsic fluorescence emission maximum of the enzyme was at 350 nm under neutral conditions, and at 355 nm under denaturing conditions. Between pH 1.0-2.5 the enzyme exists in a partially unfolded state with minimum or no tertiary structure, and no proteolytic activity. At still lower pH, the enzyme regains substantial secondary structure, which is predominantly $\beta$-sheet conformation and shows a strong binding to 8-anilino-1-napthalene-sulfonic acid (ANS). In the presence of salt, the enzyme attains a similar state directly from the native state. Under neutral conditions, the enzyme was stable in urea, while the guanidine hydrochloride (GuHCl) induced equilibrium unfolding was cooperative. The GuHCl induced unfolding transition curves at pH 3.0 and 4.0 were non-coincidental, indicating the presence of intermediates in the unfolding pathway. This was substantiated by strong ANS binding that was observed at low concentrations of GuHCl at both pH 3.0 and 4.0. The urea induced transition curves at pH 3.0 were, however, coincidental, but non-cooperative. This indicates that the different structural units of the enzyme unfold in steps through intermediates. This observation is further supported by two emission maxima in ANS binding assay during urea denaturation. Hence, denaturant induced equilibrium unfolding pathway of ervatamin B, which differs from the acid induced unfolding pathway, is not a simple two-state transition but involves intermediates which probably accumulate at different stages of protein folding and hence adds a new dimension to the unfolding pathway of plant proteases of the papain superfamily.

• Analytical Science and Technology
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• v.10 no.3
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• pp.196-202
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• 1997

New vanadium(V) complex, $(NH_4)_2[VO_2NTA]$, has been synthesized and its structure has been determined by solution and solid-state NMR spectroscopies as well as X-ray crystallography. The unit cell of the monoclinic crystals contains four complexes with $a=6.923(1){\AA}$, $b=8.824(2){\AA}$, $c=19.218(11){\AA}$ and ${\beta}=91.60(3)^{\circ}$ in the space group of $P2_1/n$. The $[VO_2NTA]^{2-}$ anion has distorted octahedral geometry with cis-$VO_2$ moiety. It is confirmed that the octahedral geometry is retained in both of solution and solid-state complexes.

• International Journal of Naval Architecture and Ocean Engineering
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• v.2 no.2
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• pp.112-118
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• 2010

The numerical study about the vortex-induced vibration and vortex shedding in the wake has been presented. Prior to the numerical simulation of flexible riser systems concerning engineering conditions, efficiency validating of the proposed FSI solution method have been performed. The comparison between numerical simulation and published experimental data shows that the CFD method designed for FSI solution could give acceptable result for the VIV prediction of flexible riser/pipe system. As meaningful study on VIV and vortex shedding mode with the focus on flexible riser model systems, two kinds of typical simulation cases have been carried out. One was related to the simulation of vortex visualization in the wake for a riser model subject to forced oscillation, and another was related to the simulation of fluid-structure interaction between the pipes of coupled multi-assembled riser system. The result from forced oscillation simulation shows that the vortex-induced vibration with high response frequency but small instantaneous vibration amplitude contributes to vortex conformation as much as the forced oscillation with large normalized amplitude does, when the frequency of forced oscillation was relatively high. In the multi-assembled riser systems, it has been found that the external current velocity and the distance between two pipes are the critical factors to determine the vibration state and the steady vibration state emerging in quad-pipe system may be destroyed more easily than dual-pipe system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.4
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• pp.1892-1903
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• 2016

Mobile social network is becoming more and more popular with respect to the development and popularity of mobile devices and interpersonal sociality. As the amount of social data increases in a great deal and cloud computing techniques become developed, the architecture of mobile social network is evolved into cloud-based that mobile clients send data to the cloud and make data accessible from clients. The data in the cloud should be stored in a secure fashion to protect user privacy and restrict data sharing defined by users. Ciphertext-policy attribute-based encryption (CP-ABE) is currently considered to be a promising security solution for cloud-based mobile social network to encrypt the sensitive data. However, its ciphertext size and decryption time grow linearly with the attribute numbers in the access structure. In order to reduce the computing overhead held by the mobile devices, in this paper we propose a new Outsourcing decryption and Match-then-decrypt CP-ABE algorithm (OM-CP-ABE) which firstly outsources the computation-intensive bilinear pairing operations to a proxy, and secondly performs the decryption test on the attributes set matching access policy in ciphertexts. The experimental performance assessments show the security strength and efficiency of the proposed solution in terms of computation, communication, and storage. Also, our construction is proven to be replayable choosen-ciphertext attacks (RCCA) secure based on the decisional bilinear Diffie-Hellman (DBDH) assumption in the standard model.