• Journal of the Korean Geotechnical Society
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• v.25 no.6
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• pp.47-57
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• 2009

In this study, the ultimate lateral load capacity of pile driven into multi-layered soil was estimated using cone penetration test results and a method was proposed to reflect multi-layered soil conditions. For multi-layered specimens prepared with different relative density at different layers, the cone penetration tests and lateral pile load tests were conducted. Based on the test results, measured and estimated values of the ultimate lateral load were compared and analyzed. The estimated results were obtained from the methods proposed by Broms (1964), Petrasovits & Award (1972) and Prasad & Chari (1999). The method was proposed for modifying the earth pressure distribution of Prasad & Chari (1999) to consider multi-layered soil conditions. From the analysis, it was seen that results obtained from the proposed method showed improvement with less data scatter similarly to those obtained from Broms (1964) and Petrasovits & Award (1972)'s methods.

• Journal of the Korean Magnetics Society
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• v.27 no.4
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• pp.115-122
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• 2017

The antiferromagnet IrMn based four different GMR-SV multilayers on Corning glass were prepared by using ion beam deposition and DC magnetron sputtering system. The magnetoresistance (MR) properties for single-type and dual-type GMR-SV multilayer films were investigated through the measured major and minor MR curves. The exchange bias coupling field ($H_{ex}$) and coercivity ($H_c$) of pinned layer, the $H_c$ and interlayer exchange coupling field ($H_{int}$) of free layer for the dual-type structure GMR-SV multilayer films consisted of top IrMn layer were 410 Oe, 60 Oe, 1.6 Oe, and 7.0 Oe, respectively. The minor MR curve of two free layers was performed the squarelike feature having a MR ratio of 8.7 % as the sum of 3.7 % and 5.0 %. The value of average magnetic field sensitivity (MS) was maintained at 2.0 %/Oe. Also, the magnetoresistance properties of the single-type and dual-type structure GMR-SV multilayer films consisted of bottom IrMn layer were decreased more than those of top IrMn layer. Two antiparallel states of magnetization spin arrays of the pinned and free layers in the dual-type GMR-SV multilayer films occurred the maximum MR value by the effect of spin dependence scattering.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.11
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• pp.2922-2931
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• 1994

We propose a modified 6-node element, where the sampling point of Gauss quadrature moved in the thickness direction. The modified 6-node element has been applied to static problems and forced motion analyses. In this study, this method is extended to the finite element analysis of the natural frequencies of two dimensional problems. We also propose a modified 16-node element for three dimensional problems, which behaves much like a 20-node element with smaller degree of freedom. The modified 6-node and 16-node elements have been applied to the modal analyses of beams and plates, respectively. The results agree well with the results of the 8-node or 20-node element models.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.1
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• pp.9-17
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• 2011

In this paper, the general equation of motion of damped sandwich beam with multi-viscoelastic material layer was derived based on the equation presented by Mead and Markus. The viscoelastic layer, which has characteristics of complex shear modulus, was assumed to be dominantly under shear deformation. The equation of motion of n-layered damped sandwich beam in bending could be represented by (n+3)th order ordinary differential equation. Finite element model for the n-layered damped sandwich beam was formulated and programmed using higher order shape functions. Several numerical examples were implemented to show the effects of damped material.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.608-611
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• 2005

In this paper the general equation of motion of damped sandwich beam including arbitrary viscoelastic material layer was derived based on the equation presented by Mead and Markus. The equation of motion of n-layered sandwich beam was represented by (n+3)th order ordinary differential equation. It was verified that the general equation of motion derived in this paper could represent the equations of motions for single-layered, three-layered, five-layered and multi-layered damped beam. Finite element method for the arbitrary-layered damped beam was formulated and programmed using higher order shape functions. Several numerical examples were implemented to show the effects of damped material.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.5
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• pp.486-492
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• 1999

The purpose of this research was to find out what is the dominant factor determining the $H_{ex}$ and the $H_C$ of Mn-Ir/Ni-Fe multilayers with different buffer layers. Regardless of (111) texture of Mn-Ir layer, all samples showed over the $H_{ex}$ of 155 Oe. We found out the $H_{ex}$ and the $H_C$ of Mn-Ir/Ni-Fe multilayers depend on interface morphology and grain size of Mn-Ir layer at the interface between Mn-Ir and Ni-Fe layers. The dependence of magnetroesistance ratio and coupling field on the thickness of ferromagnetic layer, thickness of Cu layer and different buffer layers have been studied. Maximum magnetoresistance ratio appeared for the sample Ta(5 nm)/Mn-Ir(10 nm)/Ni-Fe(7.5 nm)/Cu(2 nm)/Ni-Fe(6 nm)/Ta(5 nm)/Si. Magnetoresistance ratio may be related to grain of ferromagnetic layer. Coupling field may be related to the roughness and the grain size of ferromagnetic layer in the spin-valve multilayers.

• International Journal of Highway Engineering
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• v.10 no.4
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• pp.91-101
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• 2008

A multi layered elastic analysis program, IDYSPAP, was developed. The objective of this study was to develop the IDYSPAP program on Graphic User Interface environment for field engineers using Visual Basic, which was considered span of multi-wheels and maximum 4 axles using superposition of linear elastic theorem. It is suggested that this study considers algorithm with dynamic properties of asphalt layer on various temperature and non-linear properties of subbase and subgrade on stress non-linearity for asphalt pavement structure. This Program was modified to divide asphalt layer automatically according to layer division concept. The developed program was verified with initial measuring data in test road sections of KEC (Korea Expressway Co.) using laboratory test results.

• The Journal of the Korea Contents Association
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• v.14 no.2
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• pp.294-307
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• 2014

The purpose of this study is to examine the trajectory of early adolescent aggression and to assess the effects of perceived family factors on it. This study investigated the changes in aggression over time and the effects of three family factors, parental attachment, parental monitoring, and family conflict, on the changes using multilevel modeling. The data from Korea Youth Panel Survey(KYPS) of fourth graders who were followed over five years were analyzed. The results indicated that there was a significant average increase followed by a slight decrease in aggression over time; that is, the data followed a quadratic trend. Parental attachment, parental monitoring, and family conflict had significant time-independent effects on aggression, while only family conflict had a significant time-dependent effect on aggression. These results imply that family factors need to be emphasized in planning prevention and intervention programs to reduce aggression during adolescence.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.479-479
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• 2016

국내 하천에는 하천을 가로지르는 보나 낙차공과 같은 횡단구조물이 약 5만여개에 달하고 있다. 이러한 보/낙차공과 같은 하천횡단구조물에는 구조물을 월류하여 떨어지는 부분의 세굴을 막기 위하여 apron(물받이공)을 조성하도록 되어있고, 물받이공 하류부 세굴을 막기 위하여 사석을 깔거나, 돌망태를 설치하여 이 부분에서의 세굴을 막아 하상을 보호하도록 하고 있다. 그러나 사석이나 돌망태공, 블록을 이용한 보호공은 한 번 설치되면 이들 공법이 제자리에 남아 있는 한 세굴 방지에 좋은 효과를 발휘한다는 장점이 있지만 포설된 공법은 시간이 지남에 따라 혹은 홍수로 인해 이동되거나 소실되는 문제가 발생되며, 최종적으로 하천횡단구조물의 안전성에도 영향을 미치게 된다. 이와 더불어 강우량의 증대 및 집중호우 등 돌변하는 기후변화로 하천환경변화에 대한 적용 가능한 기술이 미비하다. 따라서 하천에 유해한 물질을 방출시키지 않고 하천환경 및 하천 생물의 생활사에 영향을 주지 않는 무 저독성 소재를 활용하여 치수적으로 수리적 안정성을 강화시키고, 생태적으로도 건강한 생태하천 복원 기술개발이 요구되는 실정이다. 본 연구에서는 무독성 소재를 활용하여 보 하류부에 자연친화적인 하상보호공으로 다층다공성 하상보호기술을 개발하였으며, 개발된 하상보호기술을 CFD 3차원 수치해석과 실내실험을 통하여 수리적 안전성을 검토하였다. 또한 개발된 기술은 김해시 대청천 하류 일부구간에 시범적으로 적용하였고, 시범사업 시공 전 중 후 각 단계에서 물리, 화학, 생물 모니터링을 통하여 개발기술의 현장 적용성을 검증하였다.

• The Journal of the Acoustical Society of Korea
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• v.13 no.4
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• pp.60-68
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• 1994

In this paper we propose a new Hybrid learning rule applied to multilayer feedforward neural networks, which is constructed by combining Hebbian learning rule that is a good feature extractor and Back-Propagation(BP) learning rule that is an excellent classifier. Unlike the BP rule used in multi-layer perceptron(MLP), the proposed Hybrid learning rule is used for uptate of all connection weights except for output connection weigths becase the Hebbian learning in output layer does not guarantee learning convergence. To evaluate the performance, the proposed hybrid rule is applied to classifier problems in two dimensional space and shows better performance than the one applied only by the BP rule. In terms of learning speed the proposed rule converges faster than the conventional BP. For example, the learning of the proposed Hybrid can be done in 2/10 of the iterations that are required for BP, while the recognition rate of the proposed Hybrid is improved by about $0.778\%$ at the peak.