• Journal of Welding and Joining
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• 제32권2호
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• pp.43-47
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• 2014

Famous artificial neural network (ANN) is applied to predict proper process window of arc welding. Target weldment is variously combined lap joint fillet welding of automotive steel plates. ANN's system variable such as number of hidden layers, perceptrons and transfer function are carefully selected through case by case test. Input variables are welding condition and steel plate combination, for example, welding machine type, shield gas composition, current, speed and strength, thickness of base material. The number of each input variable referred in welding experiment is counted and provided to make it possible to presume the qualitative precision and limit of prediction. One of experimental process windows is excluded for predictability estimation and the rest are applied for neural network training. As expected from basic ANN theory, experimental condition composed of frequently referred input variables showed relatively more precise prediction while rarely referred set showed poorer result. As conclusion, application of ANN to arc welding process window derivation showed comparatively practical feasibility while it still needs more training for higher precision.

• 한국소음진동공학회논문집
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• 제12권11호
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• pp.873-881
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• 2002

The fluid induced vibration (FIV) phenomena of an equivalent airfoil system of MAV have been investigated in low Reynolds number flow region. Unsteady flows with viscosity are computed using two-dimensional incompressible Navier-Stokes equations. The present fluid/structure interaction analysis is based on one of the most accurate computational approach with computational fluid dynamics (CFD) and computational structural dynamics (CSD) techniques. The highly nonlinear fluid/structure interaction phenomena due to severe flow separations have been analyzed for the low Reynolds region that has a dominancy of flow viscosity. The effects of Reynolds number and initial angle of attack on the fluid/structure coupled vibration instability are shown and the qualitative trend of FIV phenomenon is investigated.

• Structural Engineering and Mechanics
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• 제70권3호
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• pp.367-380
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• 2019

The paper concerns topology and geometry optimization of statically determinate beams with arbitrary number of supports. The optimization problem is treated as a bi-criteria one, with the objectives of minimizing the absolute maximum bending moment and the maximum deflection for a uniform gravity load. The problem is formulated and solved using the Pareto optimality concept and the lexicographic ordering of the objectives. The non-dominated sorting genetic algorithm NSGA-II and the local search method are used for the optimization in the Pareto sense, whereas the genetic algorithm and the exhaustive search method for the lexicographic optimization. Trade-offs between objectives are examined and sets of Pareto-optimal solutions are provided for different topologies. Lexicographically optimal beams are found assuming that the maximum moment is a more important criterion. Exact formulas for locations and values of the maximum deflection are given for all lexicographically optimal beams of any topology and any number of supports. Topologies with lexicographically optimal geometries are classified into equivalence classes, and specific features of these classes are discussed. A qualitative principle of the division of topologies equivalent in terms of the maximum moment into topologies better and worse in terms of the maximum deflection is found.

• Nuclear Engineering and Technology
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• 제54권9호
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• pp.3336-3346
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• 2022

In general, a number of severe accident scenarios derived from Level 2 probabilistic safety assessment (PSA) are typically grouped into several categories to efficiently evaluate their potential impacts on the public with the assumption that scenarios within the same group have similar source term characteristics. To date, however, grouping by similar source terms has been completely reliant on qualitative methods such as logical trees or expert judgements. Recently, an exhaustive simulation approach has been developed to provide quantitative information on the source terms of a large number of severe accident scenarios. With this motivation, this paper proposes a machine learning-based categorization method based on exhaustive simulation for grouping scenarios with similar accident consequences. The proposed method employs clustering with an autoencoder for grouping unlabeled scenarios after dimensionality reductions and feature extractions from the source term data. To validate the suggested method, source term data for 658 severe accident scenarios were used. Results confirmed that the proposed method successfully characterized the severe accident scenarios with similar behavior more precisely than the conventional grouping method.

• Archives of Plastic Surgery
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• 제49권5호
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• pp.689-695
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• 2022

Background Lymphaticovenular anastomosis (LVA) is an effective, functional treatment for limb lymphedema. This study reports an alternative surgical approach to lymphedema treatment without the use of indocyanine green mapping. Methods A retrospective analysis was performed on 29 consecutive lymphedema patients who underwent LVAs from January 2015 to December 2020, whereby incisions were made along the anatomy of the superficial venous systems in both upper and lower extremities around the joint areas. The evaluation included qualitative assessments and quantitative volumetric analyses. Result The mean number of anastomoses was 3.07, and the operative time was 159.55 minutes. Symptom improvement was recorded in 86.21% of the patients, with a mean volume reduction of 32.39%. The lymphangitis episodes decreased from 55.17% before surgery to 13.79% after surgery, and the median number of lymphangitis episodes per year decreased from 1 before surgery to 0 after surgery. Conclusions The superficial venous anatomical approach is an easy way to start a lymphedema practice using LVA without other advanced surgical equipment. With this reliable technique, microsurgeons can perform LVA procedures and achieve good results.

• Asia Marketing Journal
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• 제20권2호
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• pp.1-27
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• 2018

This study examines the effects of dependence and conflict on organizational performances in partnership, qualitatively (trust) and quantitatively (sales) under four control variables (period of business, number of goods, competition density, and number of employees). Also, this study presents termination cost and alternative attractiveness as the antecedents of dependence, goal incongruity and unfairness as the antecedents of conflict. As the results of analysis with survey data from 360 distributors in manufacturer-distributor partnership, 7 hypotheses are supported and 2 hypotheses are rejected. The results of structural equation modeling (SEM) verify that termination cost increases dependence, that alternative attractiveness reduces dependence, that goal incongruity and unfairness increase conflict, that dependence reduces conflict, that dependence increases trust, and that conflict reduces trust. However, unexpectedly, dependence reduces sales, and conflict has no impact on sales. The results of this study provide insightful implications theoretically and managerially to scholars and practitioners interested in partnership.

• Journal of Applied and Pure Mathematics
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• 제4권1_2호
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• pp.27-36
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• 2022

An innovation diffusion model is proposed model consists of three classes, namely, a non-adopter class, adopter class innovation-I, and adopter class innovation-II in a partially competitive and cooperative market. The proposed model is analyzed with the help of the qualitative theory of a system of ordinary differential equations. Basic influence numbers associated with first and second innovation $R_{0_1}$ and $R_{0_2}$ respectively in the absence of each other are quantified. Then the overall basic influence number (R₀) of the system is assessed for analyzing stability in the market in different situations. Sensitivity analysis of basic influence numbers associated with first and second innovation in the absence of each other is carried out. Numerical simulation supports our analytical findings.

• Journal of Acupuncture Research
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• 제26권2호
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• pp.147-158
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• 2009

Objectives : The purpose of this study is to review the recent research trends of evidence based medicine, especially human randomized controlled trials on acupuncture. Methods : The articles were collected by retrieving the database of Pubmed and Journal of Korean Acupuncture & Moxibustion Society. The retrieving period was from October 2003 to September 2008, and the search term was 'acupuncture'. The articles were classified according to their publication journals, countries, publication years, targeted diseases, types of acupuncture and types of control. Results : In total, 558 articles in Pubmed and 35 articles in Journal of Korean Acupuncture & Moxibustion Society were searched. The number of articles on acupuncture research has increased with higher rate since 2000, but the Qualitative development has not achieved the same amplitude. Studies in Korea were insufficient both in Qualitative and Quantitative aspects. In countries, China had the most papers, and in targeted diseases, pain diseases were most dominant. In the types of acupuncture, classical acupuncture, and in the types of control, conventional western treatment showed the highest frequency. Conclusions: We need to do many-sided and more high Quality researches on acupuncture. For that, well-designed randornized trials are absolutely necessary.

• 재활간호학회지
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• 제11권1호
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• pp.32-40
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• 2008

Purpose: This study used a phenomenological method, which is a qualitative study, in order to understand the vivid experience of parents who have a disabled child. Methods: The number of participants was 10. The subjects of this study were parents who are raising their disabled child who attends a special school or normal middle or high schools in D city. The period for collecting materials was from September 2005 to July 2007. The phenomenological analysis method suggested by Giorgi was used. Results: The meanings of the child parenting experience of parents with a disabled child are (1) feeling of frustration of the delayed treatment, (2) difficult to accept the diagnosis of disability, (3) having eyes centered on her child, (4) accepting the disabled child, (5) giving all his energy to his disabled child, (6) making efforts for his family's unity, (7) recognizing the difficulty of parenting disabled child, (8) recognizing the difficulty of education for disabled child, (9) feeling pitiful for his their normal children, (10) planning for disabled child's future. Conclusions: All the programs for disabled child should be programed for their entire life. It is necessary to provide physical, psychological, emotional, social and economic nursing intervention to relieve or reduce the burden of parents with disabled children.

• 한국수학교육학회지시리즈A:수학교육
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• 제49권1호
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• pp.67-83
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• 2010

The purpose of this study was to analyze the research trends of elementary mathematics education with regard to the topics, methods, subjects, and mathematical contents of such research. For this purpose, the papers published in domestic journals during the recent 5 years (2004-2009) were analyzed. A total of 383 papers from 8 professional journals were analyzed with the 4 criteria. First, the frequent research topics included instructional design and methods, learners' perspectives and abilities, and analysis of curriculum and textbooks in order. Second, qualitative research methodology was used twice as many as quantitative one. Whereas a survey was the most frequent quantitative research method, content analysis and case study were for qualitative methods. Third, research subjects included mainly typical students, specifically fifth and sixth graders. Papers dealing with lower graders or low-achievers as well as pre-service teachers were rare. Lastly, whereas the research on geometry as well as number and operations was active, that of measurement as well as probability and statistics was not. On the basis of these results, this paper includes several implications for the future research direction in elementary mathematics education.