• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.6
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• pp.885-895
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• 1994

In this paper, we propose the one-Ampere conductor method which is able to calculate the flux distribution conceptually and easily, and the improved winding method which suppresses space harmonics of magnetormotive force and enhances the coefficient of utilization of primary iron core in tubular linear induction motor. We carry out no-load test to verify effectiveness of proposed method and analyze characteristics by finite element method. As a result, performances are improved and propriety of primary iron core is enhanced comparing with conventional model.

• Journal of Korean Academy of Rural Health Nursing
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• v.14 no.2
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• pp.38-46
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• 2019

Purpose: The purpose of this study was to analyze differences in the needs of primary health care posts before 2008 and after 2009. Methods: For the final analysis data on 1,905 public health centers and 1,521 public health practitioners were analyzed. The chi-test was used to examine differences between the employees before and after 2008 in general, and T-test for differences in core competencies and job training needs. The test was carried out during June and July, 2017. Results: There were statistically significant differences in general characteristics, future health clinic function, necessity for core competency education, and for job education. Conclusion: Information on the need for new job training should include information the use of public health center information systems, drug mechanisms, medication guidance, discrimination of major symptoms, treatment for common diseases, patient referral and follow-up, health management for elders, dementia management, and chronic disease management. In future job training, it is necessary to elaborate intensively details and evaluate effectiveness.

• Journal of Digital Convergence
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• v.12 no.8
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• pp.175-186
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• 2014

The purpose of this study is to demonstrate the effectiveness of core competency courses by scrutinizing H Corporation case. The primary data survey was taken from direct and indirect participants of H Corporation core competency courses. The findings from the study are as follow. Firstly, before-and-after average differences were significant in inspecting core competency courses. Secondly, participants' own expected core competency was comparatively lower than how observers evaluated the participants. Thirdly, Core competency courses directly and indirectly influenced on the business performance. Therefore, the conclusions of the study are firstly, core competency courses may work effectively for the goal of the company in changing employees' organizational behavior. Secondly, for the better result of the core competency courses, customized and integrated learning transfer model for the particular company should be designed from the beginning of the education.

• Journal of Engineering Education Research
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• v.24 no.4
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• pp.3-20
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• 2021

As we have become more interested in 'competency' that means ability to do something around the world, the competency of the best performers has also been introduced in the university curriculum as a concept of core competency. Research continues on why this competency-based education is needed compared to existing academic-oriented education, how it can be introduced into existing curricula, and how it can be developed and evaluated in detail. This study develops and validates core competency assessment tools that can diagnose core competencies of engineering students. Therefore, this research paper conducted a literature review related to core competencies and also core competency assessment tools of university students. It seeks to explore the implications of core competency assessment tools for engineering students and then lay the foundation for competency-based teaching and learning at engineering colleges. And also it defines the concepts of core competencies and each core competency of engineering students through prior research analysis of competence, core competence, and core competence of university students. The primary core competency assessment tool consisted of sub-factors and questions of core competencies. It were modified through the expert validation of the primary one and then it was used as a core competency assessment tools for preliminary investigation. The core competency assessment tools for engineering students are consisted of 6 competencies, 22 sub-factors, and 91 questions. There are core competencies as follows: engineering basic competencies, major engineering competencies, self-management competencies, communication competencies, interpersonal competencies, global competencies. The preliminary survey was conducted on 426 engineering students attending the Engineering Education FESTA 2019. The preliminary findings were derived by conducting exploratory factor analysis, confirmatory factor analysis, question characteristics analysis, and reliability analysis for validation. The core competency assessment tools developed through this study can be used to verify the effectiveness of the curriculum and programs for students at engineering colleges. In addition, the developed core competencies, sub-factors, and questions can be utilized in a series of courses that design, conduct, and evaluate engineering curricula and programs as competency-based curriculum. The significance of this study is to lay the groundwork for providing competency-based education engineering students to develop core competencies.

• The KSFM Journal of Fluid Machinery
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• v.2 no.1 s.2
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• pp.56-63
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• 1999

In this study, the performance prediction programs for centrifugal pumps are developed. To estimate the losses in the centrifugal pump impellers, a two-zone model and TEIS(two elements in series) model are applied to the program. The basic concept of a two zone model considers the primary zone that is an isentropic core flow and the secondary zone that has a non-isentropic region at the impeller exit. The flow goes through two different zones and is mixed out at the impeller exit and the mixing process occurs with an increase in entropy, a decrease in total pressure. The level of the core flow diffusion in an impeller was calculated using TEIS(two elements in series) model. The effects of various parameters which are used in this program on the prediction of head and efficiency are discussed. The correlation curves used to select the effectiveness of the primitive TEIS model were suggested according to the specific speed of the centrifugal pumps.

• 유체기계공업학회:학술대회논문집
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• 1998.12a
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• pp.33-41
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• 1998

In this study, the performance prediction programs for centrifugal pumps are developed. To estimate the losses in the centrifugal pump impellers, two-zone model and TEIS(two elements in series) model are applied to the program. The basic concept of two zone model considers the primary zone that is an isentropic core flow and the secondary zone that is non-isentropic region at the impeller exit. The flows through two different zones mixed out at the impeller exit and the mixing process occurs with an increase in entropy, a decrease in total pressure. The level of the core flow diffusion in a impeller was calculated using TEIS(two elements in series) model. The effects of various parameters which are used in this program on the prediction of head and efficiency are discussed. The correlation curves to select the effectiveness of the primitive TEIS model were suggested according to the specific speed of the centrifugal pumps.

• Korean Medical Education Review
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• v.26 no.1
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• pp.55-69
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• 2024

Amid the increasing interest in medical humanities education, this study developed a medical humanities course that utilized design thinking to foster creative thinking, problem-solving, and collaboration skills that pre-medical students should possess. The course's efficacy was assessed by evaluating improvements in core design thinking skills. The present study was conducted among 83 first-year medical students after planning and implementing a design thinking course. The reflection journals written by students along the course of the class were examined using the template analysis technique to evaluate the effectiveness of the class. The study's primary findings showed the successful development of step-by-step medical humanities education content utilizing design thinking and its practical implementation in a class. Moreover, the course improved students' core design thinking skills effectively, and in a balanced way. These results illustrate the effective application of design thinking in medical school through a medical humanities course. These findings indicate that a medical humanities course can help medical students showcase their abilities to collaborate and solve problems in the real world. This paper suggests the need for further research to develop a curriculum that integrates design thinking and investigate the relationship between medical students' core competencies and design thinking-based courses.

• Nuclear Engineering and Technology
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• v.41 no.5
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• pp.575-602
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• 2009

In the wake of the Three Mile Island accident, vigorous research efforts were initiated to acquire a basic knowledge of the progression and consequences of accidents that involve a substantial degree of core degradation and melting. The primary emphasis of this research was placed on containment integrity, with: i) hydrogen combustion-detonation, ii) steam explosion, iii) direct containment heating (DCH), and iv) melt attack on the BWR Mark-I containment shell identified as energetic processes that could lead to early containment failure (i.e., within the first 24 hours of the accident). Should the core melt fail the reactor vessel, then non-condensable gas production from Molten Core-Concrete Interaction (MCCI) was identified as a mechanism that could fail the containment by pressurization over the long term. One signification question that arose as part of this investigation was the effectiveness of water in terminating an MCCI by flooding the interacting masses from above, thereby quenching the molten core debris and rendering it permanently coolable. Successful quenching of the core melt would prevent basemat melt through, as well as continued containment pressurization by non-condensable gas production, and so the accident progression would be successfully terminated without release of radioactivity to the environment. Based on these potential merits, ex-vessel corium coolability has been the focus of extensive research over the last 20 years as a potential accident management strategy for current plants. In addition, outcomes from this research have impacted the accident management strategies for the Gen III+LWR plant designs that are currently being deployed around the world. This paper provides: i) an historical overview of corium coolability research, ii) summarizes the current status of research in this area, and iii) highlights trends in severe accident management strategies that have evolved based on the findings from this work.

• Steel and Composite Structures
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• v.52 no.4
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• pp.487-499
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• 2024

The primary objective of this study is to analyze the free vibration behavior of a sandwich cylindrical shell with a defective core and wavy carbon nanotube (CNT)-enhanced face sheets, utilizing the three-dimensional theory of elasticity. The intricate equations of motion for the structure are solved semi-analytically using the generalized differential quadrature method. The shell structure consists of a damaged isotropic core and two external face sheets. The distributions of CNTs are either functionally graded (FG) or uniform across the thickness, with their mechanical properties determined through an extended rule of mixture. In this research, the conventional theory regarding the mechanical effectiveness of a matrix embedding finite-length fibers has been enhanced by introducing tube-to-tube random contact. This enhancement explicitly addresses the progressive reduction in the tubes' effective aspect ratio as the filler content increases. The study investigates the influence of a damaged matrix, CNT distribution, volume fraction, aspect ratio, and waviness on the free vibration characteristics of the sandwich cylindrical shell with wavy CNT-reinforced face sheets. Unlike two-dimensional theories such as classical and the first shear deformation plate theories, this inquiry is grounded in the three-dimensional theory of elasticity, which comprehensively accounts for transverse normal deformations.

• Journal of Power Electronics
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• v.14 no.5
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• pp.882-889
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• 2014

This paper presents a zero voltage switching (ZVS) converter with three resonant tanks. The main advantages of the proposed converter are its ability to reduce the switching losses on the power semiconductors, decrease the current stress of the passive components at the primary side, and reduce the transformer secondary windings. Three resonant converters with the same power switches are adopted at the low voltage side to reduce the current rating on the transformer windings. Using a series-connection of the transformer secondary windings, the primary side currents of the three resonant circuits are balanced to share the load power. As a result, the size of both the transformer core and the bobbin are reduced. Based on the circuit characteristics of the resonant converter, the power switches are turned on at ZVS. The rectifier diodes can be turned off at zero current switching (ZCS) if the switching frequency is less than the series resonant frequency. Therefore, the reverse recovery losses on the rectifier diodes are overcome. Experiments with a 1.6kW prototype are presented to verify the effectiveness of the proposed converter.