• Structural Engineering and Mechanics
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• v.73 no.5
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• pp.501-513
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• 2020

In the present work, the optimization of machining parameters to achieve the desired technological parameters such as surface roughness, tool radial vibration and material removal rate have been carried out using response surface methodology (RSM). The hard turning of EN19 alloy steel with coated carbide (GC3015) cutting tools was studied. The main problem faced in manufacturer of hard and high precision components is the selection of optimum combination of cutting parameters for achieving required quality of surface finish with maximum production rate. This problem can be solved by development of mathematical model and execution of experiments by RSM. A face centred central composite design (FCCD), which comes under the RSM approach, with cutting parameters (cutting speed, feed rate and depth of cut) was used for statistical analysis. A second-order regression model were developed to correlate the cutting parameters with surface roughness, tool vibration and material removal rate. Consequently, numerical and graphical optimization were performed to obtain the most appropriate cutting parameters to produce the lowest surface roughness with minimal tool vibration and maximum material removal rate using desirability function approach. Finally, confirmation experiments were performed to verify the pertinence of the developed mathematical models.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.3
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• pp.117-124
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• 2021

The development of IOT technology and artificial intelligence technology is promoting the smartization of manufacturing system. In this study, data extracted from acceleration sensor and current sensor were obtained through experiments in the cutting process of SKD11, which is widely used as a material for special mold steel, and the amount of tool wear and product surface roughness were measured. SVR (Support Vector Regression) is applied to predict the roughness of the product surface in real time using the obtained data. SVR, a machine learning technique, is widely used for linear and non-linear prediction using the concept of kernel. In particular, by applying GSVQR (Generalized Support Vector Quantile Regression), overestimation, underestimation, and neutral estimation of product surface roughness are performed and compared. Furthermore, surface roughness is predicted using the linear kernel and the RBF kernel. In terms of accuracy, the results of the RBF kernel are better than those of the linear kernel. Since it is difficult to predict the amount of tool wear in real time, the product surface roughness is predicted with acceleration and current data excluding the amount of tool wear. In terms of accuracy, the results of excluding the amount of tool wear were not significantly different from those including the amount of tool wear.

• Journal of Korean society of Dental Hygiene
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• v.19 no.1
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• pp.1-17
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• 2019

This study investigates the overall research trends and related factors affecting the turnover of dental hygienists in Korea during the past 10 years (2007-2017) and analyzed the differences in the results of the research according to the main measurement tools. The literature review focused on turnover of dental hygienists in Korea. Inclusion criteria of selected studies were as follows: the domestic and foreign academic journals and theses published for the past 10 years (between 2007-2017). The most commonly used tool for measuring dental hygienist turnover was a tool developed by Lawler. The most used significant general characteristics is age and income, Job satisfaction (57.1%) and organizational commitment (40.0%) were the most frequently used predictors of turnover. The variables used for each turnover measurement tool were different, showing that the study results was different from according to the variables and significance level. Although there have been many studies related to the turnover of dental hygienists, different results have been shown depending on the measurement tools. When conducting research related to dental hygienist turnover, specific and clear presentation of measurement tool selection or development is needed.

• Journal of Korean Academy of Nursing
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• v.51 no.3
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• pp.305-319
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• 2021

Purpose: The purpose of this study was to develop a measurement tool for a positive nursing organizational culture and to verify its reliability and validity. Methods: A conceptual framework and construct factors were extracted through an extensive literature review and in-depth interviews with nurses. The final version of the preliminary tool for the main survey was confirmed by experts through a content validity test and a preliminary survey of 40 nurses. Subsequently, the final tool was developed using a validity and reliability test containing 43 preliminary items. The final version of the tool was used with 327 hospital nurses in the testing phase for the main survey to assess validity and reliability. Results: From the factor analysis, 4 factors and 26 items were selected. The factors were positive leadership of the nursing unit manager, pursuit of common values, formation of organizational relationships based on trust, and a fair management system. The entire determination coefficient was 67.7%. These factors were verified through convergent, discriminant, and concurrent validity testing. The internal consistency reliability was acceptable (Cronbach's α = .95). Conclusion: Both the validity and reliability of the scale were confirmed demonstrating its utility for measuring positive nursing organizational culture. It is expected to be used for education, research, and practical performance policies regarding the nursing organizational culture.

• Journal of Home Health Care Nursing
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• v.27 no.3
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• pp.259-270
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• 2020

Purpose: This study aimed to identify nursing competencies of outpatient nurses, to develop a tool to assess the same, and to verify the validity and reliability of the tool. Method: Preliminary items of the scale were developed based on a literature review and nurses' interviews. The tool's content validity was verified by an expert panel and by conducting a pilot study. Subsequently, to verify the validity and reliability of the scale, data were collected from 233 outpatient nurses from 7 certified tertiary hospitals. Data were analyzed using exploratory factor analysis, independent t-test, and internal consistency and correlation analysis. Result: The factor analysis revealed the following 9 factors for the 48 items of the scale: organizational management, customer orientation, personality and ethics, problem solving, nursing practice, interpersonal relationships, communication, crisis management, and professionalism. The Cronbach's α coefficient of the final instrument was .97. Conclusion: The tool developed in this study exhibited adequate validity and reliability. It was effective in reflecting the changing roles of outpatient nurses. Therefore, in future, this tool is expected to help improve outpatient nurses' competencies and nursing quality.

• Journal of Korean Society of Transportation
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• v.3 no.1
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• pp.76-85
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• 1985

The significant role of transportation system for economic development process has been recognized, but the argument that transportation improvements stimulate economic development has brought sometimes no resonance in lacking of a plausible theory on the conditions and process of economic development by transportation investment. This paper reviews the theory on regional differentiation of transportation system and shows why and how the installation of a new transportation system or the improvements of the old transportation quality differentiate the spatial order of economic activities. It presents the interaction between the change of transportation quality with introducing of definition "transportation value" as tool of its determination and economic activities following the regional differentiation process, which result means regional defferentiation of niveau of economic development.

• Research in Mathematical Education
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• v.11 no.3
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• pp.177-184
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• 2007

The purpose of this paper is to introduce the development of a new Lesson Video-Case Lab (LVCL) program in Suzhou, China. This program involves the creation of several series of hypermedia video-cases on teaching and learning designed to facilitate mathematics teachers' professional development. Each of these video-cases consists of lesson clips, case questions, interviews with experts, comments by peers, responses by students and other related resources. The study has implications pertaining to the use of technology in teacher development, the production of hypermedia video-cases, as well as research on case-based pedagogy and pedagogy in general.

• The Journal of Society for e-Business Studies
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• v.3 no.1
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• pp.81-94
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• 1998

In Client/Server environments, an employee should be able to access only applications which were assigned to him/her. That makes it difficult to share information among employees. The development of intranet system made it possible to share more information and to access broader information. In this paper, we present a parts management system developed by using Intrabuilder which is an intranet development tool. We intend to suggest a prototype which can guide the development of more delicate and complete parts management systems in the future.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.47-48
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• 2007

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.09a
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• pp.360-362
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• 2010

축구 경기는 22명의 선수와 하나의 공을 포함하는 대표적인 이동 객체 연구의 응용분야이다. 본 논문에서는 선수와 공의 궤적정보를 분석하여 축구 경기의 전략 및 전술을 분석하기 위한 도구, 본 논문에서는 이 도구를 SATO(Soccer strategy Analysis Tool)이라 한다,를 소개한다. SATO 시스템의 부분적인 결과로, 본 논문에서는 축구 경기에서 매우 중요한 공격적인 패스를 정의하고 SATO 시스템을 통해 이를 분석한다.