• 제목/요약/키워드: field variables method

검색결과 546건 처리시간 0.025초

The construction of second generation wavelet-based multivariable finite elements for multiscale analysis of beam problems

  • Wang, Youming;Wu, Qing;Wang, Wenqing
    • Structural Engineering and Mechanics
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    • 제50권5호
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    • pp.679-695
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    • 2014
  • A design method of second generation wavelet (SGW)-based multivariable finite elements is proposed for static and vibration beam analysis. An important property of SGWs is that they can be custom designed by selecting appropriate lifting coefficients depending on the application. The SGW-based multivariable finite element equations of static and vibration analysis of beam problems with two and three kinds of variables are derived based on the generalized variational principles. Compared to classical finite element method (FEM), the second generation wavelet-based multivariable finite element method (SGW-MFEM) combines the advantages of high approximation performance of the SGW method and independent solution of field functions of the MFEM. A multiscale algorithm for SGW-MFEM is presented to solve structural engineering problems. Numerical examples demonstrate the proposed method is a flexible and accurate method in static and vibration beam analysis.

Feature Selection Methodology in Quality Data Mining

  • Soo, Nam-Ho;Halim, Yulius
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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    • pp.698-701
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    • 2004
  • In many literatures, data mining has been used as a utilization of data warehouse and data collection. The biggest utilizations of data mining are for marketing and researches. This is solely because of the data available for this field is usually in large amount. The usability of the data mining is expandable also to the production process. While the object of research of the data mining in marketing is the customers and products, data mining in the production field is object to the so called 4MlE, man, machine, materials, method (recipe) and environment. All of the elements are important to the production process which determines the quality of the product. Because the final aim of the data mining in production field is the quality of the production, this data mining is commonly recognized as quality data mining. As the variables researched in quality data mining can be hundreds or more, it could take a long time to reveal the information from the data warehouse. Feature selection methodology is proposed to help the research take the best performance in a relatively short time. The usage of available simple statistical tools in this method can help the speed of the mining.

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Spatial Downscaling of AMSR2 Soil Moisture Content using Soil Texture and Field Measurements

  • Na, Sangil;Lee, Kyoungdo;Baek, Shinchul;Hong, Sukyoung
    • 한국토양비료학회지
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    • 제48권6호
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    • pp.571-581
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    • 2015
  • Soil moisture content is generally accepted as an important factor to understand the process of crop growth and is the basis of earth system models for analysis and prediction of the crop condition. To continuously monitor soil moisture changes at kilometer scale, it is demanded to create high resolution data from the current, several tens of kilometers. In this paper we described a downscaling method for Advanced Microwave Scanning Radiometer 2 (AMSR2) Soil Moisture Content (SMC) from 10 km to 30 m resolution using a soil texture and field measurements that have a high correlation with the SMC. As a result, the soil moisture variations of both data (before and after downscaling) were identical, and the Root Mean Square Error (RMSE) of SMC exhibited the low values. Also, time series analyses showed that three kinds of SMC data (field measurement, original AMSR2, and downscaled AMSR2) had very similar temporal variations. Our method can be applied to downscaling of other soil variables and can contribute to monitoring small-scale changes of soil moisture by providing high resolution data.

Numerical simulation of the flow in pipes with numerical models

  • Gao, Hongjie;Li, Xinyu;Nezhad, Abdolreza Hooshmandi;Behshad, Amir
    • Structural Engineering and Mechanics
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    • 제81권4호
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    • pp.523-527
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    • 2022
  • The objective of this study is to simulate the flow in pipes with various boundary conditions. Free-pressure fluid model, is used in the pipe based on Navier-Stokes equation. The models are solved by using the numerical method. A problem called "stability of pipes" is used in order to compare frequency and critical fluid velocity. When the initial conditions of problem satisfied the instability conditions, the free-pressure model could accurately predict discontinuities in the solution field. Employing nonlinear strains-displacements, stress-strain energy method the governing equations were derived using Hamilton's principal. Differential quadrature method (DQM) is used for obtaining the frequency and critical fluid velocity. The results of this paper are analyzed by hyperbolic numerical method. Results show that the level of numerical diffusion in the solution field and the range of well-posedness are two important criteria for selecting the two-fluid models. The solutions for predicting the flow variables is approximately equal to the two-pressure model 2. Therefore, the predicted pressure changes profile in the two-pressure model is more consistent with actual physics. Therefore, in numerical modeling of gas-liquid two-phase flows in the vertical pipe, the present model can be applied.

한국의류산업학회지 논문의 양적정보에 대한 연구동향 (Research Trends in Fashion and Textiles Research Journal through Quantitative Informations)

  • ;전은경
    • 한국의류산업학회지
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    • 제19권1호
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    • pp.70-78
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    • 2017
  • To predict and foster professional research issues for the present and future, it is important to understand the stream of research trends. This study is to provide information of research trend through analysis of quantitative variables in 1,374 articles from the first issue to the present(2015) of the Fashion and Textiles Research Journal. As a result, in the former periods, articles in the field of textile science & technology and fashion design & historical concerns, and articles that used experiments and others as a research method were dominant; in the latter periods, articles in the field of fashion marketing & merchandising and apparel production & technology, and articles that used survey as a research method were dominant. According to each detailed research field and method, there were significant differences in the number of pages, authors and references of articles. In addition, it was found that the number of pages and the number of references increased sharply in the latter period, indicating that the contents of the papers were more detailed and faithful to references of other studies. Through the analysis of this study, it was found that Fashion and Textiles Research Journal published a variety of articles in the academic fields. The research information analyzed in this study will contribute to the future design for the research as well as the academic societies.

한국 아동 미술치료중재 프로그램 연구 동향 (The Trends of Research on Children Art Therapy Program Intervention in Korea)

  • 김원순
    • 한국임상보건과학회지
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    • 제5권1호
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    • pp.790-802
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    • 2017
  • Purpose. This study was designed to analyze recent trends in Children Art Therapy Program Intervention research in Korea and suggest future research directions in this area. Methods. Studies(29) selected from http://www.riss4u.net for last 15 year were used. They were analyzed by publication type, field and design of the study, study participants and outcome variables used in intervention studies. Results. 1. As for academic field, there are 15 art therapy academic journals(51.72%), which made up the largest proportion. 2. As for subjects of the study, there are 17 articles of Elementary (58.6%) education, which made up the largest proportion. As for the subjects of sex, 8 articles (27.59%) are for male students, 7 (24.14%) articles are for female students and 14 articles (48.28.%) are for both male and female students. 3. As for 7 articles of Art therapy(24.14%), 7 articles of Group Art therapy (24.14%) made up the largest proporton 4. As for the intervention study method according to the subjects of suicide intervention program, there are 15 articles of monoclonal Pre and post design (51.72%),which made up the largest proportion. 5. As for the sample size, there were 16.79 persons in the treatment group on average, 13.28 persons in the control group have average and the total persons were 10 on average. The treatment period was 12 weeks on average and the average number of treatment times was 18. The places of treatment were 3 schools (10.38%), which made up the largest proportion. 19. The results of the experimental study support the research hypothesis of all 29 programs. Conclusions. As the above, the studies on the art therapy intervention program for children are increasing but the subjects are overly weighted toward elementary school students. Although the content of the art therapy intervention program was varied, it was found that the development of the program using various art media which can induce the motivation of the child was lacking. In addition, the place of experimental mediation was concentrated on psychology center as 12(41.38%), indicating that there are not enough places to connect with community organizations such as schools and hospitals. The variables of experimental study were focused on psychological variables and it was found that there were insufficient application of various variables including coping method, social support, and physiological variables.

저밀도 폴리에틸렌 일렉트렉트에 있어서 케리어의 성질과 Trap 깊이 해석에 대한 연구 (A study on the analysis of carrier properties and trap energy depth in the low-density polythylene electrets)

  • 이준웅
    • 전기의세계
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    • 제29권8호
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    • pp.511-518
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    • 1980
  • The thermostimulated discharge currents of low-density polyethylene electrets were measured versus the principal experimental variables. Several electrode types were used for the charging and discharging procedures. The results led to know the experimental conditions for the heterocharge and homocharge accumulating and decreasing. The electronic structure parameters of polyethylene such as trap level, density of traps, hopping length, mobility, trap time constants were deduced. A method for evaluating the local electric field inside the electret is proposed.

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Automatic Creation of 3D Artificial Flowers with Interactive Evaluation on Evolutionary Engine

  • Min, Hyeun-Jeong;Cho, Sung-Bae
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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    • pp.702-705
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    • 2003
  • Directed graph and Lindenmayer system (L-system) are two major encoding methods of representation to develop creatures in an application field of artificial life. It is difficult to structurally define real morphology using the L-systems which are a grammatical rewriting system because they represent genotype as loops, procedure calls, variables, and parameters. This paper defines a class of representations called structured directed graph and interactive genetic algorithm for automatically creating 3D flower morphology. The experimental results show that natural flower morphology can be created by the proposed method.

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균형적 시간관이 청년기 역경 후 성장에 미치는 영향력: 사회적 유대감의 매개효과 (The Effect of a balanced time perspective on growth after adversity in adolescence: Mediating Effect of Social Connectedness)

  • 김민진;박정윤
    • 한국심리학회지 : 문화 및 사회문제
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    • 제28권2호
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    • pp.163-186
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    • 2022
  • 본 연구는 역경 후 성장을 일으키는 요인의 영향력을 밝히고 상담 및 임상 현장에서 활용할 방안을 제안하려는 목적으로 진행되었다. 이를 위해 한국에 거주하는 청년 208명을 대상으로 자료를 수집하여 SPSS 25.0, AMOS 26.0 통계 프로그램으로 수집된 자료를 분석하였다. 본 연구는 역경 후 성장을 균형적 시간관과 사회적 유대감의 영향력으로 보고 두 변인의 관계가 역경 후 성장에 미치는 영향력을 살펴보고자 하였다. 대상자의 인구통계학적 특성 파악을 위해 빈도분석을 실시하고 변인들의 경향성을 살펴보기 위해 기술통계 분석을 실시하였으며, 변인 간의 상관관계를 파악하기 위해 Pearson 적률상관분석을 실시하였다. 역경 후 성장에 주요변인들이 미치는 영향력을 알아보기 위해 위계적 회귀분석을 실시하였으며, 연구모형의 검증을 위해 경로분석을 실시하고 부트스트랩 방법을 사용하여 간접효과의 유의성을 확인하였다. 본 연구의 주요 결과는 다음과 같다. 첫째, 인구통계학적 변인 중 종교가 역경 후 성장에 유의미한 영향력을 보였다. 둘째, 역경 후 성장에 균형적 시간관과 사회적 유대감이 유의한 영향을 미치는 것으로 나타났다. 셋째, 균형적 시간관이 사회적 유대감에 영향을 미치고 본 과정을 통해 역경 후 성장이 일어나는 경로를 밝혔다. 이는 역경 후 성장을 위해서 균형적 시간관과 사회적 유대감 모두 중요하며 상담 및 임상 현장에서 활용의 필요성을 시사한다.

충격해석을 위한 새로운 불연속 시간적분법의 개발 (Development of a New Discontinuous Time Integration Method for Transient Analysis of Impact Phenomena)

  • 조진연;김승조
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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    • pp.407-412
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    • 1998
  • In this work, a new time integration method is proposed using the generalized derivative concept to simulate the dynamic phenomena having sudden constraint occurring in dynamic contact/impact problems. By the adoption of the generalized derivative concept and jump assumption, discontinuity can be incorporated in time integration and as a result, the algorithm does not need any other special consideration of jumps in dynamic field variables due to sudden constraint like dynamic contact-release conditions. To observe the characteristics of the proposed time integration method, the stability and convergence analyses are carried out. In numerical tests, several dynamic contact/impact problems are analyzed by straightforward application of the proposed time integration method with the exterior penalty method.

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