• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.934-937
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• 2006

This investigation presents a topology formulation to design optimal poroelastic acoustic foams to maximize absorbing ability. For successful formulation, a single set of equations based on Biot's theory is adopted and an appropriate material interpolation strategy is newly developed. Because there was no earlier attempt to solve poroelastic acoustic foam design problems in topology optimization setting, many challenging issues including modeling and interpolation must be addressed. First, the simulation accuracy by a proposed unified model encompassing acoustic air and poroelastic material was checked against analytical and numerical results. Then a material interpolation scheme yielding a distinct acoustic air-poroelastic material distribution was developed. Using the proposed model and interpolation scheme, the topology optimization of a two-dimensional poroelastic acoustic foam for maximizing its absorption coefficient was carried out. Numerical results show that the absorption capacity of an optimized foam layout considerably increases in comparison with a nominal foam layout.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.506-507
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• 2007

Lateral Information Propagation Neural Networks (LIPN) is proposed for on-line interpolation. The proposed neural network technique is the real time computation method through the inter-node diffusion. In the network, a node corresponds to a state in the quantized input space. Through several simulation experiments, real time reconstruction of the nonlinear image information is processed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.559-560
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• 2007

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1479-1481
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• 2003

The aim of this paper was mainly to interpret the real information-missing patch of image by using the kriging interpolation technology of spatial statistics. The TM Image of the Jingouling Forest Farm of Wangqing Forestry Bureau of Northeast China on 1 July 1997 was used as the tested material in this paper. Based on the classification for the TM image, the information pixel-missing patch of image was interpolated by the kriging interpolation technology of spatial statistics theory under the image treatment software-ERDAS and the geographic information system software-Arc/Info. The interpolation results were already passed precise examination. This paper would provide a method and means for interpreting the information-missing patch of image.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.5
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• pp.421-425
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• 2008

In this research, a 8-bit CMOS 2 stage folding A/D converter is designed, For low power consumption and small chip size, the A/D converter is designed by using folding and interpolation circuit. Folding circuit is composed of the transistor differential pairs which are connected in parallel. It reduces the number of comparator drastically. The analog block composed of folding block, current interpolation circuit, and three stage current comparator is designed with differential-mode for high speed operation. The simulation in a $0.35\;{\mu}m$ CMOS process. shows DNL and SNDR of 0.5LSB and 47 dB at 250 MHz/s sampling frequency.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.65-85
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• 1999

Objectives: To determine the effect of interpolation functions when processing the digital periapical images. Material and Methods: The digital images were obtained by Digora and CDR system on the dry skull and human subject. 3 oral radiologists evaluated the 3 portions of each processed image using 7 interpolation methods, and ROC curves were obtained by trapezoidal methods. Results: The heighest Az value(0.96) was obtained with cubic spline method and the lowest Az value(0.03) was obtained with facet model method in Digora system. The heighest Az value (0.79) was obtained with gray segment expansion method and the lowest Az value(0.07) was obtained with facet model method in CDR system. There was significant difference of Az value in original image between Digora and CDR system at a=0.05 level. There were significant differences of Az values between Digora and CDR images with cubic spline method, facet model method, linear interpolation method and non-linear interpolation method at α=0.1 level.

• 한국전산유체공학회:학술대회논문집
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• 2009.04a
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• pp.283-289
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• 2009

In level set method, material properties are made to change smoothly across an interface of two materials with different properties by introducing an interpolation or smoothing scheme. So far, the weighted arithmetic mean (WAM) method has been exclusively adopted in level set method, without complete assessment for its validity. We showed here that the weighted harmonic mean (WHM) method for rate constants of various rate processes, including viscosity, thermal conductivity, electrical conductivity, and permittivity, gives much more accurate results than the WAM method. The selection of interpolation scheme is particularly important in multi-phase electrohydrodynamic problems in which driving force for fluid flow is electrical force exerted on the phase interface. Our analysis also showed that WHM method for both electrical conductivity and permittivity gives not only more accurate, but also more physically realistic distribution of electrical force at the interface. Our arguments are confirmed by numerical simulations of drop deformation under DC electric field.

• Steel and Composite Structures
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• v.35 no.1
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• pp.129-145
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• 2020

In typical, structural topology optimization plays a significant role to both increase stiffness and save mass of structures in the resulting design. This study contributes to a new numerical approach of topologically optimal design of Mindlin-Reissner plates considering Winkler foundation and mathematical formulations of multi-directional variable thickness of the plate by using multi-materials. While achieving optimal multi-material topologies of the plate with multi-directional variable thickness, the weight information of structures in terms of effective utilization of the material at the appropriate thickness location may be provided for engineers and designers of structures. Besides, numerical techniques of the well-established mixed interpolation of tensorial components 4 element (MITC4) is utilized to overcome a well-known shear locking problem occurring to thin plate models. The well-founded mathematical formulation of topology optimization problem with variable thickness Mindlin-Reissner plate structures by using multiple materials is derived in detail as one of main achievements of this article. Numerical examples verify that variable thickness Mindlin-Reissner plates on Winkler foundation have a significant effect on topologically optimal multi-material design results.

• Geomechanics and Engineering
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• v.11 no.1
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• pp.59-76
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• 2016

Penetration problems in geomechanics are common. Usually the soil is heavily disturbed around the penetrating bodies and large deformations and distortions can occur. The simulation of the installation of displacement piles is a good example of the interest of these types of problems for geomechanics. In this paper the Material Point Method is used to overcome the difficulties associated with the simulations of problems involving large deformation and full displacement type penetration. Recent modifications of the Material Point Method known as Generalized Interpolation Material Point and the Convected Particle Domain Interpolation are also used and evaluated in some of the examples. Herein a footing submitted to large settlements is presented and simulated, together with the processes associated to a driven pile under undrained conditions. The displacements of the soil surrounding the pile are compared with those obtained by the Small Strain Path Method. In addition, the Modified Cam Clay model is implemented in a code of MPM and used to simulate the process of driving a pile in dry sand. Good and rather encouraging agreement is found between compared data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11b
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• pp.7-12
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• 2004

New modular Lateral Information Propagation Networks(LIPN) has been designed. The LIPN has shown to be useful for interpolation of information[3]. The problem is the fact that only the small number of nodes can be implemented in a IC chip with the circuit VLSI technology. The proposed modular architecture is for enlarging the neural network through inter module connections. For such inter module connections, the host(computer or logic) mediates the exchange of information among modules. Also border nodes in each module have capacitors for temporarily retaining the information from outer modules. Simulation of interpolation with the designed LIPN has been done through various experiments.