• Structural Engineering and Mechanics
• /
• v.13 no.2
• /
• pp.231-239
• /
• 2002

The problem of dynamic analysis of truss structures based on probability is studied in this paper. Considering the randomness of both physical parameters (elastic module and mass density) of structural materials and geometric dimension of bars respectively or simultaneously, the stiffness and mass matrixes of the elements and structure have been built. The structure dynamic characteristic based on probability is analyzed, and the expressions of numeral characteristics of inherence frequency random variable are derived from the Rayleigh's quotient. The method of structural dynamic analysis based on probability is developed. Finally, two examples are given.

• Proceedings of the KIEE Conference
• /
• 1995.07c
• /
• pp.1442-1444
• /
• 1995

In this study, we confirmed that the crystallinity and the mechanical properties of polycrystalline Silicon(poly-Si) deposited on the poly-oxide are better than those of poly-Si on the conventional sacrificial layers that is CVD oxide layer or PSG. But the etch rate of poly-oxide is poor than that of the CVD oxide layer or PSG. Therefore, to make the best use of small stress and fast etch rate, we fabricated the double oxide layer; 10%-thick poly-oxide on 90%-thick CVD oxide or PSG. To estimate structure deformation by stress, we fabricated the test structures; cantilever. bridge and ring/beam structure and estimated by SEM. As the results, all structure is expressed the deformed structure by residual stress(tensile stress) and the deformation of the structure layer on the double oxide layer is small compared with that of the structure layer on the CVD oxide layer or PSG. And, the etch rate of the double oxide layer is enhanced compared with that of the poly-oxide.

• Bulletin of the Korean Chemical Society
• /
• v.15 no.7
• /
• pp.545-549
• /
• 1994

Using the extended Hackel molecular orbital method in connection with the tight binding model, we have studied electronic structure and related properties of the charged cluster models relating to superconducting $YBa_{2}Cu_{3}O_{7-x}$, crystals in which O-atoms in regular sites were selectively replaced with Se atoms. In analogy to the isomorphism problem with molecules, we discuss all possible combinations of Se-substitutions in O-sites with one, two, and four Se atoms. The calculations are carried out within charged cluster models for analogues of YBa-copper oxide. Our results suggest that the electronic structure of the symmetrically Se-substituted or Se-added compound is closer to that of the YBCO superconducting compound than that obtained from the unsymmetrical substitution. This applies in particular if O is replaced with Se around the Cu(1) site. Symmetrical substitutions in the $CuO_2$ layers give rise to large variations in the electronic structure of $YBa_{2}Cu_{3}O_{7}$. This is consistent with the fact that superconductivity is very sensitive to the electronic population of the $CuO_2$ layers.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2007.05a
• /
• pp.141.1-141.1
• /
• 2007

• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.233-234
• /
• 2008

Radiation characteristics of a microstrip patch antenna integrated with a UC-EBG (Uniplanar Compact Electromagnetic Bandgap) structure and a Mushroom EBG structure are compared. Radiation characteristics of a patch antenna integrated with a Mushroom EBG structure are better than those of a patch antenna integrated with a UC-EBG structure.

• Applied Science and Convergence Technology
• /
• v.25 no.1
• /
• pp.19-24
• /
• 2016

In this study, we evaluated the change of electronic structure during redox process in cerium-doped $ZrO_2$ grown by sol gel method. By sol-gel method, we could obtain cerium-doped $ZrO_2$ in high oxygen partial pressure and low temperature. After post annealing process in nitrogen ambient, the film is deoxidized. We used spectroscopic and theoretical methods to analysis change of electronic structure. X-ray absorption spectroscopy (XAS) for O K1-edge and Density Functional Theory (DFT) calculation using VASP code were performed to verify the electronic structure of the film. Also, high resolution x-ray photoelectron spectroscopy (HRXPS) for Ce 3d was carried out to confirm chemical bond of cerium doped $ZrO_2$. Through the investigation of the electronic structure, we verified as followings. (1) During reduction process, binding energy of oxygen is increase. Simultaneously, oxidation state of cerium was change to 4+ to 3+. (2) Cerium 4+ and cerium 3+ states were generated at different energy level. (3) Absorption states in O K edge were mainly originated by Ce 4+ $f_0$ and Ce 3+, while occupied states in valance band were mainly originated from Ce 4+ $f_2$.

• Bulletin of the Korean Chemical Society
• /
• v.24 no.6
• /
• pp.837-842
• /
• 2003

In ab initio molecular dynamics, whenever information about the potential energy surface is needed for integrating the equations of motion, it is computed “on the fly” using electronic structure calculations. For Born-Oppenheimer methods, the electronic structure calculations are converged, whereas in the extended Lagrangian approach the electronic structure is propagated along with the nuclei. Some recent advances for both approaches are discussed.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2003.09a
• /
• pp.571-574
• /
• 2003

This research is aimed to automate the generating process of the database from paper based table forms like this work. The registration table has so complicate table structures, ana in this research we used the registration tables as an example of general table structure understanding. We propose a table structure understanding system for some table types, and it has some steps. The first step is that the document images on paper are read from the image scanner. The second step is that a document image segments into some tables. In the third step, the character strings is extracted using image processing technology and the property of the character strings is determined. And the structured database is generated automatically. The proposed system consists of two systems. "Master document generation system" is used for the table form definition, and it doesn′t include the handwritten characters. "Structure analysis system for complete d table" is used for the written form, and it analyzes the table form filled in the handwritten character. We implemented the system using MS Visual C＋＋ on Windows, and it can get the correct extraction rate 98％ among 51 registration tables written by the different students.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.635-639
• /
• 2004

In this paper, we present a novel approach for the structure of Fuzzy Neural Network(FNN) based on wavelet function and apply this network structure to the modeling of chaotic nonlinear systems. Generally, the wavelet fuzzy model(WFM) has the advantage of the wavelet transform by constituting the fuzzy basis function(FBF) and the conclusion part to equalize the linear combination of FBF with the linear combination of wavelet functions. However, it is very difficult to identify the fuzzy rules and to tune the membership functions of the fuzzy reasoning mechanism. Neural networks, on the other hand, utilize their learning capability for automatic identification and tuning. Therefore, we design a wavelet based FNN structure(WFNN) that merges these advantages of neural network, fuzzy model and wavelet transform. The basic idea of our wavelet based FNN is to realize the process of fuzzy reasoning of wavelet fuzzy system by the structure of a neural network and to make the parameters of fuzzy reasoning be expressed by the connection weights of a neural network. And our network can automatically identify the fuzzy rules by modifying the connection weights of the networks via the gradient descent scheme. To verify the efficiency of our network structure, we evaluate the modeling performance for chaotic nonlinear systems and compare it with those of the FNN and the WFM.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.377-377
• /
• 2010

FINEMET type nanocrystalline materials synthesized by controlled crystallization of amorphous ribbons[1] exhibit excellent soft magnetic properties making them attractive for technological applications. Present work reports the electronic structure studies of Co-substituted FINEMET to get information on the effect of successive Co substitution on local environment around Fe and Co atom by using near edge x-ray absorption fine structure (NEXAFS) and x-ray magnetic circular dichroism (XMCD) measurements. NEXAFS spectroscopy and XMCD measurements have been carried out at Fe $L_{3,2}$ and Co $L_{3,2}$-edges to investigate the chemical states and electronic structure of FINEMET [$(Fe_{100-x}Co_x)_{78}Si_9Nb_3Cu_1Ba$](0$L_{3,2}$-edge reveal that Fe is in 2+ state and in tetrahedral symmetry with other elements. The magnetic properties exhibiting soft magnetic behavior[2] are discussed on the basis of the electronic structure studied through XMCD.