• Title/Summary/Keyword: fundamental solution.

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The change of Industrial Human Resource Structure in Korea Economy and the Corresponding Measures of Casting Industry Field (한국 산업인력구조의 변화와 주조산업계 대응방안)

  • Lee, Seung-Jae;Cho, In-Sung
    • Journal of Korea Foundry Society
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    • v.38 no.2
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    • pp.27-31
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    • 2018
  • The lack of industrial manpower that Korean companies have been suffering in 21st century is largely responsible for the low-fertility phenomenon. This research suggests an alternative solution with a program for fostering foreign laborers with technical skills in casting industry. Industrial manpower growth is feasible through accepting migrants who have had official education on the fundamental industrial technologies provided by Korean government. These technically trained migrants who can keep economical self-perpetuating ability are can help to effectively address the problem of the declining working-age population and the decreasing potential growth rate in Korea.

Earthquake Response Analysis through a Fundamental Solution to Multilayered Half-Planes (다층반무한 기본해를 이용한 지진응답해석)

  • 김문겸
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1997.04a
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    • pp.128-135
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    • 1997
  • The indirect boundary integral equation is formulated to analyze the behavior of a cavity in a multilayered half-plane subjected to earthquake waves. This formulation uses the fundamental solutions that are numerically calculated by the generalized transmission and reflection coefficient method. The free surface of the cavity without external excitation influences the behavior of the half-plane. Consequently this analysis adds the consideration of scattering-field into the analysis and the total motion field of the cavity is decomposed into the free-field and scattering-field motions. The free-field motion is obtained from the modification of the transmission and reflection coefficient method. The scattering-field motion is calculated is calculated by the indirect boundary value problem which has the ficticious boundaries and sources. In this study, P wave, SV wave, SH wave, and Rayleigh wave are analyzed respectively.

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Effect of Aggregates Kinds and Superplasticizer on Fundamental Properties of Ultra High Performance Concrete (골재 종류 및 SP제 변화가 초고성능 콘크리트 기초적 특성에 미치는 영향)

  • Lee, Hong-Kyu;Jung, Sang-Woon;Jo, Man-Ki;Han, Dong-Yeop;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.55-56
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    • 2014
  • In this research, the effect of types of aggregate and SP on fundamental properties of ultra-high performance concrete of 80 MPa of compressive strength was evaluated to provide solution for high cost of ultra-high performance concrete. As the results of a series of tests, the mixture using limestone and silica aggregates showed improved workability rather than the mixture using granite aggregate. For compressive strength of UHPC, the UHPC mixtures using limestone and silica aggregates showed higher compressive strength than the UHPC mixture using granite aggregate while all mixtures satisfied target compressive range.

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Analytical solutions of in-plane static problems for non-uniform curved beams including axial and shear deformations

  • Tufekci, Ekrem;Arpaci, Alaeddin
    • Structural Engineering and Mechanics
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    • v.22 no.2
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    • pp.131-150
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    • 2006
  • Exact analytical solutions for in-plane static problems of planar curved beams with variable curvatures and variable cross-sections are derived by using the initial value method. The governing equations include the axial extension and shear deformation effects. The fundamental matrix required by the initial value method is obtained analytically. Then, the displacements, slopes and stress resultants are found analytically along the beam axis by using the fundamental matrix. The results are given in analytical forms. In order to show the advantages of the method, some examples are solved and the results are compared with the existing results in the literature. One of the advantages of the proposed method is that the high degree of statically indeterminacy adds no extra difficulty to the solution. For some examples, the deformed shape along the beam axis is determined and plotted and also the slope and stress resultants are given in tables.

A Simple Technique to Predict the Natural Frequencies of the Sagged Cable Structures (케이블구조물의 고유진동수 추정을 위한 근사식)

  • Sang-Moo,Lee;Yong-Chul,Kim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.23 no.3
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    • pp.10-16
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    • 1986
  • This paper deals with a simple, approximate formula to predict the natural frequencies of the sagged cable structures. Assuming that the propagation velocity of the lateral wave is dependent only on the local mass per unit length and local tension, the explicit simple formula to predict the fundamental period is newly derived. The modified form of these formula is also presented for the prediction of the fundamental period of general shaped cable structures. The results of comparison shows fairly good agreements with experimental results and with theoretical ones. This formula is also used to predict the natural frequencies of a long vertical cable and the derived approximate formula in that case, becomes identical to the exact solution.

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Analysis of linear viscoelastic problems using boundary element method (경계요소법을 사용한 선형 점탄성문제의 해석)

  • 심우진;곽병만
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.11 no.2
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    • pp.322-330
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    • 1987
  • Isotropic linear viscoelasticity problems are analyzed numerically in time domain by Boundary Element Method with quadratic isoparametric boundary elements. Viscoelastic fundamental solutions are newly derived by using the elastic-viscoelastic correspondence principle and corresponding boundary integral equations are also presented. Numerical results of two examples are compared with the derived exact solutions to verify the accuracy and validity of the method. A detailed study on the accuracy of displacement and stress in terms of time integration step is given.

Virtual boundary element-equivalent collocation method for the plane magnetoelectroelastic solids

  • Yao, Wei-An;Li, Xiao-Chuan;Yu, Gui-Rong
    • Structural Engineering and Mechanics
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    • v.22 no.1
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    • pp.1-16
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    • 2006
  • This paper presents a virtual boundary element-equivalent collocation method (VBEM) for the plane magnetoelectroelastic solids, which is based on the fundamental solutions of the plane magnetoelectroelastic solids and the basic idea of the virtual boundary element method for elasticity. Besides all the advantages of the conventional boundary element method (BEM) over domain discretization methods, this method avoids the computation of singular integral on the boundary by introducing the virtual boundary. In the end, several numerical examples are performed to demonstrate the performance of this method, and the results show that they agree well with the exact solutions. So the method is one of the efficient numerical methods used to analyze megnatoelectroelastic solids.

Solving partial differential equation for atmospheric dispersion of radioactive material using physics-informed neural network

  • Gibeom Kim;Gyunyoung Heo
    • Nuclear Engineering and Technology
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    • v.55 no.6
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    • pp.2305-2314
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    • 2023
  • The governing equations of atmospheric dispersion most often taking the form of a second-order partial differential equation (PDE). Currently, typical computational codes for predicting atmospheric dispersion use the Gaussian plume model that is an analytic solution. A Gaussian model is simple and enables rapid simulations, but it can be difficult to apply to situations with complex model parameters. Recently, a method of solving PDEs using artificial neural networks called physics-informed neural network (PINN) has been proposed. The PINN assumes the latent (hidden) solution of a PDE as an arbitrary neural network model and approximates the solution by optimizing the model. Unlike a Gaussian model, the PINN is intuitive in that it does not require special assumptions and uses the original equation without modifications. In this paper, we describe an approach to atmospheric dispersion modeling using the PINN and show its applicability through simple case studies. The results are compared with analytic and fundamental numerical methods to assess the accuracy and other features. The proposed PINN approximates the solution with reasonable accuracy. Considering that its procedure is divided into training and prediction steps, the PINN also offers the advantage of rapid simulations once the training is over.

A Bundled Educational Solution to Reduce Incorrect Plaster Splints Applied on Patients Discharged from Emergency Department

  • Chia Wei Jennifer Ting;Shu Fang Ho;Fatimah Lateef
    • Quality Improvement in Health Care
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    • v.29 no.2
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    • pp.64-84
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    • 2023
  • Purpose:Plaster splints are routinely performed in the Emergency Department (ED) and avoidable complications such as skin ulcerations and fracture instability arise mainly due to improper techniques. Despite its frequent use, there is often no formal training on the fundamental principles of plaster splint application for a medical officer rotating through ED. We aim to use Quality Improvement (QI) methodology to reduce number of incorrect plaster splint application to improve overall patient care via a bundled educational solution. Methods: We initiated a QI program implementing concepts derived from the Institute for Healthcare Improvement models, including Plan-Do-Study-Act (PDSA) cycles, to decrease the rate of incorrect plaster splint application. A bundled education solution consisting of three sequential interventions (practical teaching session, online video lecture and quick reference cards) were formulated to specifically target critical factors that had been identified as the cause of incorrect plaster splints in ED. Results: With the QI intervention, our overall rate of incorrect plaster splints was reduced from 84.1% to 68.6% over a 6-month period. Conclusion: Following the QI project implementation of the bundled educational solution, there has been a sustained reduction in incorrect plaster splints application. The continuation of the training program also ensures the sustainability of our efforts in ED.

The Effect of the Solution-focused group counseling program on problem-solving capacity of the nursing students (해결중심 집단상담 프로그램이 간호학생의 문제해결 능력에 미치는 효과)

  • Kim, Hyeon-Mi;Choi, Yeon-Hee;Jeon, Eun-Young
    • The Korean Journal of Rehabilitation Nursing
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    • v.6 no.2
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    • pp.183-191
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    • 2003
  • Purpose: To examine the effect of the solution-focused group counseling program on the nursing students' problem-solving capacity. Methods: The research design was one-group pretest-posttest design in quasi-experimental research. The subjects were 16 sophomore nursing students being in K university located in D city, Korea. The period of this research was from January 9 to February 20, 2002, from January 10 to February 21, 2003. The group counseling program that was developed by Kim, Hyeon Mi (2001) on the basis of the fundamental principles of solution-focused therapy of de Shazer, et al. (1986) and the solution-focused group counseling process proposed by Selekman (1991), LaFountain, et al. (1996) and Metcalf (1998) was used after being modified and complemented for the nursing students. The group counseling was carried out six times for 120 minutes per week. The instruments used for this study were the Problem Solving Inventory developed by Heppner and Petersen (1982) and Scaling question. Collected data were analyzed by paired t-test with SPSS program. Results: 1) Problem solving capacity increased after solution-focused group counseling program, but a significant difference was not revealed(t=0.835, p=0.057). 2) The scores of self-confidence with the problem-solving were significantly increased when it was compared with the 1st and the 6th(t=3.587, p=0.001). Conclusion: It seems that the solution-focused group counseling program should be considered as an effective nursing intervention program for the nursing students by improving self-confidence with the problem-solving. As a results, this study suggests that the specific techniques used in the solution focused therapy should be applied actively in areas of counseling and communication training for the nursing students and nurses.

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