• 제목/요약/키워드: Mixed Methods

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Optimization of flexure stiffness of FGM beams via artificial neural networks by mixed FEM

  • Madenci, Emrah;Gulcu, Saban
    • Structural Engineering and Mechanics
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    • 제75권5호
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    • pp.633-642
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    • 2020
  • Artificial neural networks (ANNs) are known as intelligent methods for modeling the behavior of physical phenomena because of it is a soft computing technique and takes data samples rather than entire data sets to arrive at solutions, which saves both time and money. ANN is successfully used in the civil engineering applications which are suitable examining the complicated relations between variables. Functionally graded materials (FGMs) are advanced composites that successfully used in various engineering design. The FGMs are nonhomogeneous materials and made of two different type of materials. In the present study, the bending analysis of functionally graded material (FGM) beams presents on theoretical based on combination of mixed-finite element method, Gâteaux differential and Timoshenko beam theory. The main idea in this study is to build a model using ANN with four parameters that are: Young's modulus ratio (Et/Eb), a shear correction factor (ks), power-law exponent (n) and length to thickness ratio (L/h). The output data is the maximum displacement (w). In the experiments: 252 different data are used. The proposed ANN model is evaluated by the correlation of the coefficient (R), MAE and MSE statistical methods. The ANN model is very good and the maximum displacement can be predicted in ANN without attempting any experiments.

변형된 스위칭 필터를 이용한 복합잡음 제거에 관한 연구 (A Study on Mixed Noise Removal using Modified Switching Filter)

  • 권세익;김남호
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2015년도 추계학술대회
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    • pp.300-303
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    • 2015
  • 디지털 영상 처리는 메모리 소자 등의 급속한 진보에 의해 다양한 응용 분야에 실용화되고 있다. 그러나 영상 처리 과정에서 여러 가지 원인에 의해 잡음이 발생하고 있으며, 이러한 잡음들을 제거하기 위한 다양한 방법들이 연구되고 있다. 일반적으로, 영상은 서로 다른 특성을 갖는 복합잡음에 의해 손상된다. 본 논문에서는 영상에 첨가된 복합잡음의 영향을 완화하기 위해, 잡음 형태에 따라 스위칭하여 처리하는 필터 알고리즘을 제안하였다. 그리고 객관적 판단의 기준으로 PSNR(peak signal to noise rato)을 사용하였으며, 기존의 방법들과 성능을 비교하였다.

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보행로봇 재활치료가 편마비 뇌졸중 환자의 보행능력에 미치는 효과: 혼합연구설계 (The Effects of Robot-Assisted Rehabilitation on the Gait Ability of Stroke Patients with Hemiplegia: A Mixed Methods Research Study)

  • 박민경;하영미;조형제;전미양
    • Journal of Korean Biological Nursing Science
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    • 제23권1호
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    • pp.72-82
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    • 2021
  • Purpose: This study used a mixed methods research design in an attempt to verify the effects of robot-assisted rehabilitation on the gait ability of stroke patients with hemiplegia, and thereby further understand the benefits and challenges of stroke patients' experiences relying on robot-assisted rehabilitation. Methods: An exploratory sequential mixed methods study design was used in order to combine both quantitative and qualitative data. For the quantitative data collection, a total of 30 stroke patients with hemiplegia were recruited from one rehabilitation hospital. Qualitative data were collected through individual interviews using semi-structured questionnaires for a group of 15 patients who were currently undergoing robot-assisted rehabilitation. The data were analyzed through qualitative content analysis. Results: As a result of the quantitative analysis, there were significant differences between the two groups in terms of daily living activity patterns, total number of steps, and average walking speed. As a result of the qualitative analysis, the four main themes derived consisted of, 'curiosity about the usage of robot-assisted rehabilitation,' 'pleasure experienced while using the robots,' 'insufficient information about robots,' and 'a lack of education about robot-assisted rehabilitation.' Conclusions: Robot-assisted rehabilitation had a significant effect on the walking ability of stroke patients with hemiplegia. Additionally, stroke patients with hemiplegia experienced difficulty during the course of their robot-assisted rehabilitation, due to a lack of sufficient information on correct usage techniques. These quantitative and qualitative findings could provide the basic foundation for the development of an educational program on robot-assisted rehabilitation.

포괄치위생관리 과정을 적용한 치주질환자의 비외과적 치주처치 효과 : 혼합연구방법 적용 (Effect of non-surgical periodontal therapy with the application of a comprehensive dental hygiene care process for periodontal disease patients: using mixed methods research)

  • 서가혜;문상은;김윤정;김선영;조혜은;강현주
    • 한국치위생학회지
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    • 제22권3호
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    • pp.161-170
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    • 2022
  • Objectives: This study aims to conduct in-depth research on the effect of non-surgical periodontal therapy (NSPT) with the application of a comprehensive dental hygiene care (CDHC) process, and provide basic data for the wide application of CDHC. Methods: From May 8, 2021 to September 24, 2021, mixed-methods research was conducted in 36 patients with periodontal diseases. A paired samples t-test was used to analyze the quantitative research data using IBM SPSS program(ver. 22.0; IBM Corp., Armonk, NY, USA) and qualitative research data were analyzed using the thematic analysis method. Results: With NSPT applying the CDHC process, the perception of periodontal health and self-efficacy of periodontal healthcare were increased (p<0.001). Presence of gingivitis, probing pocket depth, bleeding on probing rate, presence of subgingival calculus, and dental plaque index were reduced (p<0.001). Based on 195 meaningful statements, 26 concepts, 12 sub-themes, and 5 themes , , , and were drawn. Conclusions: The perception of periodontal health and the self-efficacy were improved, and substantial change in the clinical index. The CDHC application allowed the study participants to perceive the importance of dental care and professionalism of dental hygienists.

Nurses' Perceived Needs and Barriers Regarding Pediatric Palliative Care: A Mixed-Methods Study

  • Kang, Kyung-Ah;Yu, SuJeong;Kim, Cho Hee;Lee, Myung-Nam;Kim, Sujeong;Kwon, So-Hi;Kim, Sanghee;Kim, Hyun Sook;Park, Myung-Hee;Choi, Sung Eun
    • Journal of Hospice and Palliative Care
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    • 제25권2호
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    • pp.85-97
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    • 2022
  • Purpose: This study aimed to describe nurses' perceived needs and barriers to pediatric palliative care (PPC). Methods: Mixed methods with an embedded design were applied. An online survey was conducted for nurses who participated in the End-of-Life Nursing Education Consortium- Pediatric Palliative Care (ELNEC-PPC) train-the-trainer program, of whom 63 responded. Quantitative data were collected with a survey questionnaire developed through the Delphi method. The 47 items for needs and 15 items for barriers to PPC were analyzed with descriptive statistics. Qualitative data were collected through open-ended questions and analyzed with topic modeling techniques. Results: The mean scores of most subdomains of the PPC needs were 3.5 or higher out of 4, and those of PPC barriers ranged from 3.22 to 3.56, indicating the items in the questionnaire developed in this study properly reflect each factor. The needs for PPC were divided into 4 categories: "children and adolescents," "families," "PPC management system," and "community-based PPC." Meanwhile, PPC barriers were divided into 3 categories: "healthcare delivery system," "healthcare provider," and "client." The keywords derived from the topic modeling were perception, palliative, children, and education for necessities and lack, perception, medical care, professional care providers, service, and system for barriers to PPC. Conclusion: In this study, by using mixed-methods, items of nurses' perceived needs and barriers to PPC were identified, categorized, and weighted, and their meanings were explored. For the stable establishment of PPC, the priority should be given to improving perceptions of PPC, establishing an appropriate system, and training professional care providers.

A NEW PREDICTOR-CORRECTOR METHOD FOR NONCOERCIVE MIXED VARIATIONAL INEQUALITIES

  • Noor, Muhammad Aslam
    • Journal of applied mathematics & informatics
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    • 제7권2호
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    • pp.483-491
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    • 2000
  • In this paper, we use the auxiliary principle technique to suggest and analyze a class of predictor-corrector methods for solving noncoercive mixed variational inequalities. The convergence of the proposed method requires only the partially relaxed strongly monotonicity. which is even weaker than the co-coercivity. As special cases, we obtain a number of new and known results for classical variational inequalities.

EMS Rules for Balanced Factorial Designs under No Restriction on Interaction

  • Choi Byoung-Chul
    • Communications for Statistical Applications and Methods
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    • 제12권1호
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    • pp.47-59
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    • 2005
  • Expected mean square(EMS) is an important part of conducting the analysis of variance in the experimental design problem, especially in mixed or random models. We present a set of EMS rules for balanced factorial designs under no restriction on interaction. Also we point out how to use the variance component of SPSS or SAS procedure to obtain EMS.

Mixed Model with Time Effect for Analyzing Geographic Variability in Mortality Rates

  • Yong Chul Kim
    • Communications for Statistical Applications and Methods
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    • 제4권1호
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    • pp.33-39
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    • 1997
  • Tsutakawa(1988) proposed a mixed model for using empirical Bayes method to study the geographic variability in mortality rates of a disease. In particular cases of the analysis in mortality rate, we need to consider the effect of time. If observed data are collected annually for the time period, then time effect will be emphasized. Here, an extended model for estimating the geographic effect and the mortality rates of the disease with time effect is proposed.

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Modelling Count Responses with Overdispersion

  • Jeong, Kwang Mo
    • Communications for Statistical Applications and Methods
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    • 제19권6호
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    • pp.761-770
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    • 2012
  • We frequently encounter outcomes of count that have extra variation. This paper considers several alternative models for overdispersed count responses such as a quasi-Poisson model, zero-inflated Poisson model and a negative binomial model with a special focus on a generalized linear mixed model. We also explain various goodness-of-fit criteria by discussing their appropriateness of applicability and cautions on misuses according to the patterns of response categories. The overdispersion models for counts data have been explained through two examples with different response patterns.

혼합정수계획법을 위한 분지한계법의 효율적인 구현 (An efficient implementation of branch-and-cut algorithm for mixed integer programming)

  • 도승용;이상욱;임성묵;박순달
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 2002년도 춘계공동학술대회
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    • pp.1-8
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    • 2002
  • A Branch-and-Cut algorithm is a branch-and-bound algorithm in which rutting planes are generated throughout the branch-and-bound tree. It is now one of the most widespread and successful methods for solving mixed integer programming problems. In this paper we presents efficient implementation techniques of branch-and-cut algorithm for miked integer programming problems.

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