• 대한수학회논문집
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• 제20권2호
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• pp.311-319
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• 2005

In this paper we introduce a new class of parametric nonlinear implicit quasivariational inclusions and obtain some results about the existence and sensitivity analysis of solutions for this kind of quasivariational inclusions.

• International Journal of Contents
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• 제14권4호
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• pp.24-29
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• 2018

EEG-based brain-computer interfaces has focused on explicitly expressed intentions to assist physically impaired patients. For EEG-based-computer interfaces to function effectively, it should be able to understand users' implicit information. Since it is hard to gather EEG signals of human brains, we do not have enough training data which are essential for proper classification performance of implicit intention. In this paper, we improve the subject independent classification of implicit intention through the generation of additional training data. In the first stage, we perform the PCA (principal component analysis) of training data in a bid to remove redundant components in the components within the input data. After the dimension reduction by PCA, we train ICA (independent component analysis) network whose outputs are statistically independent. We can get additional training data by adding Gaussian noises to ICA outputs and projecting them to input data domain. Through simulations with EEG data provided by CNSL, KAIST, we improve the classification performance from 65.05% to 66.69% with Gamma components. The proposed sample generation method can be applied to any machine learning problem with fewer samples.

• 한국CDE학회논문집
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• 제12권3호
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• pp.220-232
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• 2007

Current geometric modeling and analysis are commonly based on B-Rep modeling and a finite elements method respectively. Furthermore, it is difficult to represent an object whose material property is heterogeneous using the B-Rep method because the B-Rep is basically used for homogeneous models. In addition, meshes are required to analyze a property of a model when the finite elements method is applied. However, the process of generating meshes from B-Rep is cumbersome and sometimes difficult especially when the model is deformed as time goes by because the topology of deforming meshes are changed. To overcome those problems in modeling and analysis including homogeneous and heterogeneous materials, we suggest a unified modeling and analysis method based on implicit representation of the model using R-function which is suggested by Rvachev. For implicit modeling of an object a distance field is approximated and blended for a complex object. Using the implicit function mesh-free analysis is possible where meshes are not necessary. Generally mesh-free analysis requires heavy computational cost compared to a finite elements method. To improve the computing time of function evaluation, we utilize GPU programming. Finally, we give an example of a simple pipe design problem and show modeling and analysis process using our unified modeling and analysis method.

• 대한수학회보
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• 제49권2호
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• pp.249-262
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• 2012

In this paper, under some suitable conditions and in virtue of a selection which depends on a vector-valued function and a feasible set map, the sensitivity analysis of a class of implicit multifunctions is investigated. Moreover, by using the results established, the solution sets of parametric vector optimization problems are studied.

• 한국전산유체공학회지
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• 제9권3호
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• pp.26-38
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• 2004

A study has been made for the investigation of the robustness and convergence of various implicit operators of the LU-SGS scheme using linear stability analysis. It is shown that the behavior of the implicit operator is not determined by its own characteristics, but is determined relatively depending on the dissipative property of the explicit operator. It is also shown that, as the dissipation level of the implicit operator increases, the robustness of the scheme increases, but the convergence rate can be deteriorated due to the excessive dissipation. The numerical results demonstrate that the dissipation level of the impliict operator needs to be higher than that of the explicit operator for computing stiff problems.

• 한국의류학회지
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• 제41권4호
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• pp.575-584
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• 2017

Previous research has investigated the influence of explicit self-esteem and depression. These studies did not examine the implicit self-esteem and depression that exist in the internal unconscious of humans that are not influenced by prejudice and social desirability. This study identifies that fashion competency (FC) encourages the implicit self-esteem and relieves the implicit depression. Implicit self-esteem and depression were measured by Implicit Association Test (IAT) utilizing reaction; FC was surveyed based on questionnaires. The data collected were analyzed using factor analysis. FC was then composed of three factors of fashion involvement, fashion innovativeness and self-confidence in fashion coordination. The results of comparing the index values that indicate IA SE (implicit association self-esteem) and IA DE (implicit association depression) of each FC group indicated that a higher FC results in a higher IA SE and lower IA DE; therefore, individuals with a higher fashion competence have a higher implicit self-esteem and a sense of well-being. The findings support previous studies in that the FC tends to be positively related to quality of life in young people.

• 토지주택연구
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• 제1권1호
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• pp.59-65
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• 2010

The paper presents a comparison between a semi-implicit time integration linear finite element implementation and fully-implicit nonlinear Newton-Raphson finite element implementation of a triphasic small strain mixture formulation of an elastic partially saturated porous medium. The pore air phase pressure pa is assumed atmospheric, i.e., $p_a$ = 0, although the formulation and implementation are general to handle increase in pore air pressure as a result of loading, if needed. The solid skeleton phase is assumed linear isotropic elastic and partially saturated 'consolidation' in the presence of surface infiltration and traction is simulated. The verification of the implementation against an analytical solution for partially saturated pore water flow (no deformation) and comparison between the two implementations is presented and the important of the porosity-dependent nature of the partially saturated permeability is assessed on comparison with a commercial code for the partially saturated flow with deformation. As a result, the response of partially saturated permeability subjected to the porosity influences on the saturation of a soil, and the different behaviors of the partially saturated soil between staggered and monolithic coupled programs is worth of attention because the negative pore water pressure in the partially saturated soil depends on the difference.

• 한국CDE학회논문집
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• 제12권4호
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• pp.274-282
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• 2007

In this paper, a method of constructing a rectangular net from unorganized point cloud data is presented. In the method an implicit surface that fits the given point data is generated by using principal component analysis(PCA) and adaptive domain decomposition method(ADDM). Then a complete and quality rectangular net can be obtained by extracting voxel data from the implicit surface and projecting exterior faces of extracted voxels onto the implicit surface. The main advantage of the proposed method is that a quality rectangular net can be extracted from randomly scattered 3D points only without any further information. Furthermore the results of this works can be used to obtain many useful information including a slicing data, a solid STL model and a NURBS surface model in many areas involved in treatment of large amount of point data by proper processing of implicit surface and rectangular net generated previously.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2010년도 정기 학술대회
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• pp.48-51
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• 2010

본 논문에서는 자유경계문제 해석을 위해 정확도가 향상된 implicit 이동최소제곱 차분법을 제시한다. 계면경계에 대한 implicit 정의로 인해 비선형 시스템이 구성되고, 매 해석단계마다 절점해와 계면경계의 위치를 반복계산을 통해 찾는다. 계면경계 결정시 속도항을 한 단계 뒤로 지연시켜 explicit하게 근사적으로 계산하던 기존 방법에 비해 계면경계의 위치를 더 정확하게 계산할 수 있고, 결과적으로 해의 정확도가 향상되었다. 계면경계 위치값이 비교적 빠른 속도로 수렴하기 때문에 많은 반복계산이 필요치 않다. 수치예제를 통해 기존의 방법으로 계산한 결과와 비교하여 새롭게 개발한 implicit 방법의 향상된 정확도를 보였다.

• 한국노년학
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• 제38권3호
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• pp.409-433
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• 2018

본 연구는 어린이가 일상에서 노인과의 접촉을 통해 노인에 대한 차별적 태도(Ageist attitude)를 완화할 수 있는지, 해당 태도의 개선방안을 탐색하였다. 명시적 태도(Explicit attitude)의 측정에 사용되는 자기보고식(Self-reported) 척도가 의식에서 여과된 수준의 편견만 반영하는 한계를 고려해, 내면의 차별적 인식을 나타내는 '암묵적 태도(Implicit attitude)'를 측정하였다. 명시적 태도 측정에는 웃는 얼굴 5점 척도를, 암묵적 태도 측정에는 어린이용 암묵적 연령 연합검사(Children Implicit Age-association Test)를 사용하였다. 서울 및 수도권 초등학교 4~6학년 초등학생 503명의 자료를 수집했으며 기술통계, 다항 및 서열 로지스틱 회귀분석 방법으로 분석하였다. 분석결과는 크게 세 가지로 요약된다. 첫째, 노인에 대한 어린이의 명시적 태도와 암묵적 태도의 예측요인이 달랐다. 이는 편견의 '표출'을 완화하는 요소를 이용해 '내적 편견'을 예측하고 개선하는 데는 한계가 있으며 따라서 암묵적 편견에 대한 별도의 접근이 필요함을 보여준다. 둘째, 어린이의 연령차별적 태도와 노인 접촉경험의 관계는 어린이와 노인의 관계특성, 그리고 접촉의 양적 측면과 질적 측면에 따라 다소 복잡한 관계를 보였다. 종합적으로 요약하면 노인을 많이 그리고 긴밀하게 만나는 아이들이 표면적으로 또는 내면적으로 연령차별적일 가능성이 낮았다. 마지막으로, 접촉질이 중요한 명시적 태도와 달리 암묵적 태도는 접촉량과 약한 관련을 보였으며, 접촉질과는 관계가 없었다. 이는 편견 완화에 접촉량보다는 질의 효과를 강조해온 집단 간 접촉이론(Intergroup contact theory)으로 설명되지 않는 결과로, 접촉의 암묵적 태도에 대한 영향을 전반적으로 검토하고 이론을 보완할 필요가 있다.