• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.660-664
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• 2014

A diesel forklift truck under 3-ton class has disadvantages in the vibration transmission path. Because the weight ratio of body structure to powertrain which is source of excitation force is lower th an a mid-class forklift. In addition, the torsional and bending vibration mode frequencies of body structure are within the engine excitation frequency range, then high idle vibration generated by resonance. In this paper vehicle body structure design and optimization technique considering idle vibration reduction are presented. Design sensitivity analysis is applied to search the sensitive of design parameters in body structure. The design parameters such as thickness and pillar cross section were optimized to increase the torsional and bending vibration mode frequencies.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.36 no.3
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• pp.49-58
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• 2020

Based on Merrill's instructional theory, this study pursued to develop a demonstration-based architectural design class operation model for the 3^rd year undergraduate students taking a Spring semester design studio class. The model was designed and used particularly to improve architectural thinking abilities of under-motivated learners. Learning effects of the model were examined based on the preliminary data obtained for 3 consecutive years, 2017 through 2019. A total of 52 students were participated in the class and observed by the instructor. Once developed, the model has been continually updated and improved based on results of each class operation. Five types of demo. were used in the model. First, direct contacts of the instructor with under-motivated learners were turned out to be the most preferred demo(demo. 4), while watching and listening of the demo(demo.3) between the instructor and motivated learners taking place in class was ranked at the second place. Belief of under-motivated learners on the instructor as a professional should be highly valued for improving their architectural thinking abilities. Second, motivated peers' direct help for under-motivated ones was placed in the third rank. Social attitudes of under-motivated learners towards accepting motivated ones' helps were determined the particular demo's appropriateness. Third, a set of guidelines for operating the model in undergraduate design studio classes were developed and suggested.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.2
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• pp.141-146
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• 2009

In this paper, a novel harmonic control circuit has been proposed for the design of high-efficiency power amplifier with Si LDMOSFET. The proposed harmonic control circuit haying the short impedances for the second- and third-harmonic components has been used to design the in/output matching network. The efficiency enhancement effect of the proposed harmonic control circuit is superior to the class-F or inverse class-F harmonic control circuit. Also, when the proposed harmonic control circuit has been adapted to the input matching network as well as the output matching network, the of ficiency enhancement effect of the proposed power amplifier has increased all the more. The measured maximum power added efficiency (PAE) of the proposed power amplifier is 82.68% at 1.71GHz band. Compared with class-F and inverse class-F amplifiers, the measured maximum PAE of the proposed power amplifier has increased in $5.08{\sim}9.91%$.

• The Transactions of the Korea Information Processing Society
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• v.7 no.3
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• pp.818-830
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• 2000

Automation tools for program analysis are needed in order to program understand and maintain, extract the characteristics of object-oriented program such as class name, member function and data member. In this paper, we carried out design and implementation of the automation tool for effective maintenance of object-oriented software. Being based on Reverse Engineering, this approach extracts class relationship information from C++ source code and generates object-oriented model of class diagram using UML as the standard object-oriented methodology. Therefore, this paper provides developers visualized including class information, definitions of classes, inheritance relationships, set relationships, and simple reference relationships. Finally in this paper, we propose a method that construct class relationship information to table in analysis state and make form of table construction to link form so tat developers can perform understanding and maintaining program efficiently. And this method enable to restructure and reuse in object-oriented model.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.24 no.4
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• pp.265-276
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• 2017

Purpose: This study was conducted to design and implement a fundamental nursing practice based on flipped learning and to examine the effects. Methods: Participants were 57 students who were taking the fundamental nursing practice course at D university in N city. The study included processes of instructional design, action/effects and reflection. Data were analyzed using paired t-test with the SPSS/WIN 23.0. Results: In the instructional design stage, the class consisted of 3 parts: outside class (pre-learning), inside class (assessment, collaborative practice, peer review, reflection), after-class (self-directed practice, feedback). In the action/effects stage, the flipped learning was applied for 15 weeks according to the instructional design and then the effects of flipped learning were evaluated. Students showed a significant improvement in self-directed learning ability (t=-3.56, p=.001) and critical thinking disposition after the class (t=-3.72, p<.001). Finally, in the reflection stage, the researchers examined whether the four pillars of flipped learning occurred. Conclusion: Findings indicate that flipped learning applied in fundamental nursing practice is effective in improving self-directed learning ability and critical thinking disposition. The action research method was a useful way to foster professor's educational competency as well as to verify effects of a new nursing education method.

• Progress in Superconductivity and Cryogenics
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• v.9 no.1
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• pp.61-66
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• 2007

A transmission class high-temperature superconducting(HTS) power cable system is being developed in Korea. For insulation design of this cable the grading method of insulating paper is proposed. Two kinds of laminated polypropylene paper that has different thickness has been used as the electrical insulation material. The use of graded insulation gives improved mechanical bending properties of the cable. In a HTS cable technology the terminations are important components. A HTS cable termination is energized with the line-to-ground voltage between the coaxial center and outer surrounding conductors. in the axial direction. There is also a temperature difference from ambient to about 77 K. For insulation design of this termination, glass fiber reinforced plastic(GFRP) was used as the insulation material of the termination body, and the capacitance-graded method is proposed. This paper will report on the experimental investigations on impulse breakdown and surface flashover characteristics of the insulation materials for insulation design of a transmission class HTS power cable and termination. Based on these experimental data, the electrical insulation design of a transmission class HTS power cable and termination was carried out.

• Journal of Engineering Education Research
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• v.23 no.1
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• pp.3-9
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• 2020

The purpose of the study was to develop the Arduino based STEAM instruction materials for creative engineering design class. PDIE model was used in this study. We developed a STEAM lesson plan and a STEAM lesson worksheet for a total of six sessions through the steps of preparation, development, implementation and evaluation. The validity of the instruction materials was evaluated by the 10 experts using a survey. The instruction materials were applied to the class (52 students attended) of the creative engineering designs unit in technology and home economics subject. The class satisfaction and the creative solving-problem ability were examined after the calss. The class satafacition was high as the average of 10 item was 4.57 (out of 5). The paired t-test was conducted to compare the means of the creative solving-problem ability. It was observed that 'understanding and mastery of knowledge, thought, function and skills in a specific domain', 'divergent thinking', 'critical and logical thinking' and ' motivational factors' were significantly increased after the class. The instruction materials develped in this study were successfully designed to enhance the creative solving-problem ability by designing creative tasks and to intrique the interest by adding visual and auditory stimuli with the Arduino.

• Journal of Korean Society for Quality Management
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• v.14 no.1
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• pp.26-32
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• 1986

A class of multi-factor designs for estimating the slope of second order response surfaces is presented. For multi-factor designs the variance of the estimated slope at a point is a function of the direction of measurement of the slope and the design. If we average the variance over all possible directions, the averaged variance is only a function of the point and the design. By choice of design, it is possible to make this variance constant for all points equidistant from the design origin. This property is called "slope-rotatability over all directions", and the necessary and sufficient conditions for a design to have this property are given and proved. The class of design with this property is mainly discussed.

• Progress in Superconductivity and Cryogenics
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• v.16 no.2
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• pp.47-53
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• 2014

In this paper, the general electromagnetic design process of a 10-MW-class high-temperature superconducting (HTS) synchronous generator that is intended to be utilized for large scale offshore wind generator is discussed. This paper presents three-dimensional (3D) electromagnetic design proposal and electrical characteristic analysis results of a 10-MW-class HTS synchronous generator for wind power. For more detailed design by reducing the errors of a two-dimensional (2D) design owing to leakage flux in air-gap, we redesign and analyze the 2D conceptual electromagnetic design model of the HTS synchronous generator using 3D finite element analysis (FEA) software. Then electrical characteristics which include the no-load and full-load voltage of generator, harmonic contents of these two load conditions, voltage regulation and losses of generator are analyzed by commercial 3D FEA software.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.737-742
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• 1994

In this paper , we propose an incremental approach for recognizing a class of machining features from a featurebased design model as a part design proceeds, utilizing various information such as nominal geometry, design intents, and design feature characteristics. The proposed apptroach can handle complex intersecting features and protrusion features designed on oblique faces. The class of recognized volumetric machining features can be expressed as Material Removal Shape Element Volumes (MRSEVs), a PDES/STEP-based library of machining features.