• Journal of Fashion Business
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• v.17 no.4
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• pp.1-21
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• 2013

A study using compare and analyze about differences among three basic pants patterns(shape and size of pattern, fitting and amount of air gap and so on) through 3D simulation. This study use 3D simulation program, DC Suite version 3.0. The results are as a follows: The results of comparison about total pants pattern shape, the ESMOD have two tucks of front and one dart of back and the Secoli and On&on have each dart of front and back. The results of estimation about total appearance, the On&on is the best of all pattern about total silhouette of front and back side and the ESMOD is the worst of all. In a case of the ESMOD, the thigh part has so many spaces between body and pants so it is rated low. When we examine about space between body and pants, amount of air gap of ESMOD is 0.6 at waist circumference and next is On&on(0.07). In case of hip circumference, the Secoli is 0.08 and the ESMOD is 0.14. The ESMOD's amount of air gap is 0.32 at thigh circumference and 0.62 at knee circumference. The Secoli's amount air gap is 0.26 at thigh circumference and 0.59 at knee circumference.

• Journal of Radiation Industry
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• v.9 no.1
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• pp.1-7
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• 2015

The trend of x-ray image sensor has been evolved from an amorphous silicon sensor to a crystal silicon sensor. A crystal silicon X-ray sensor, meaning a X-ray CIS (CMOS image sensor), is consisted of three transistors (Trs), i.e., a Reset Transistor, a Source Follower and a Select Transistor, and a photodiode. They are highly sensitive to radiation exposure. As the frequency of exposure to radiation increases, the quality of the imaging device dramatically decreases. The most well known effects of a X-ray CIS due to the radiation damage are increments in the reset voltage and dark currents. In this study, a pixel array of a X-ray CIS was made of $20{\times}20pixels$ and this pixel array was exposed to a high radiation dose. The radiation source was Co-60 and the total radiation dose was increased from 1 to 9 kGy with a step of 1 kGy. We irradiated the small pixel array to get the increments data of the reset voltage and the dark currents. Also, we simulated the radiation effects of the pixel by MCNP (Monte Carlo N-Particle) simulation. From the comparison of actual data and simulation data, the most affected location could be determined and the cause of the increments of the reset voltage and dark current could be found.

• Journal of Korean Elementary Science Education
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• v.41 no.1
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• pp.93-105
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• 2022

This study investigated the aspects of how three preservice elementary school teachers conducted the data-text transforming discourses in their science simulation teaching and how their epistemological conversations worked for learners' construction of scientific knowledge. Three preservice teachers, who had presented simulation teaching on the seasonal change of constellations, participated in the study. The results revealed that one preservice teacher, who had implemented the transforming discourses of data-to-evidence and model-to-explanation, appeared to facilitate learners' knowledge construction. The other two preservice teachers had difficulty helping learners construct science knowledge due to their lack of transforming discourses. What we should consider for improving preservice elementary school teachers' teaching competencies was discussed based on a detailed comparison of three cases of preservice teachers' data-text transforming.

• Journal of Power Electronics
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• v.9 no.4
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• pp.553-566
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• 2009

In-phase control and energy-optimized control are the two major control strategies proposed for series power quality controllers (SPQC). However quantitative analysis and comparison between these two control strategies is quite limited in previous publications. In this paper, an extensive quantitative analysis is carried out on these two control strategies through phasor diagram approach, and a detailed quantitative comparison is conducted accordingly. The load current is used as the reference phasor, and this leads to a simpler and clearer phasor diagram for the quantitative relationship. Subsequently detailed analysis of SPQC using in-phase control and energy-optimized control are provided respectively, under different modes both for under voltage/voltage sag and for over voltage/voltage swell. The closed form analytic expressions and the curves describing SPQC compensation characteristics are obtained. The detailed system power flow is figured out for each mode, and the detailed quantitative comparison between the two control strategies is then carried out. The comparison covers several aspects of SPQC, such as required compensating voltage magnitude, required capacity of energy storage component, and maximal ride-through time. In the end, computer simulation and prototype experimental results are shown to verify the validity of all the analysis and the result of the comparison.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.2
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• pp.257-268
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• 2014

In this study, flow-driven rotor simulations with a given load are conducted to analyze the operational characteristics of a vertical-axis Darrieus turbine, specifically its self-starting capability and fluctuations in its torque as well as the RPM. These characteristics are typically observed in experiments, though they cannot be acquired in simulations with a given tip speed ratio (TSR). First, it is shown that a flow-driven rotor simulation with a two-dimensional (2D) turbine model obtains power coefficients with curves similar to those obtained in a simulation with a given TSR. 3D flow-driven rotor simulations with an optimal geometry then show that a helical-bladed turbine has the following prominent advantages over a straight-bladed turbine of the same size: an improvement of its self-starting capabilities and reduced fluctuations in its torque and RPM curves as well as an increase in its power coefficient from 33% to 42%. Therefore, it is clear that a flow-driven rotor simulation provides more information for the design of a Darrieus turbine than a simulation with a given TSR before experiments.

• Women's Health Nursing
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• v.24 no.2
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• pp.150-162
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• 2018

Purpose: To identify the effects of delivery-nursing simulation education using team-based learning on the delivery nursing knowledge, self-efficacy, and clinical competence of nursing students. Methods: The study used a nonequivalent, control group, quasi-experimental design. The team-based learning was applied to the experimental group, while the individual learning was applied to the control group. Data were collected from October 12 to December 7, 2016, and analyzed using the SPSS/WIN 22.0 program. Results: Comparison between the experimental and control group showed no significant difference in delivery-nursing knowledge (t=-0.33, p=.741) or self-efficacy (t=-0.65, p=.515). However, a significant difference (t=-2.09, p=.048) in the nursing-skills aspect of clinical competence was found between the experimental and control groups after the practical simulation education. Conclusion: Delivery-nursing simulation education using team-based learning was more effective in improving the nursing-skills aspect of nursing competence than was delivery-nursing simulation education based on individual learning.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2583-2588
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• 2009

This study deals with the shock response analysis of HDD subjected to a half-sine shock pulse and its experimental verification. Comparatively, accurate computer simulation allows designers to determine complete mechanical information during the product impact time period, compared with only segmental messages by sensors in a test, to predict potential failures. But, impact/shock simulation technology is rather sensitive to various factors to predict the shock behavior without validation. In our shock simulation, the methodology of analysis with LS-DYNA3D and test validation is adopted to predict the shock behavior of HDD. We can confirm the soundness of the present shock simulation through the comparison with electromagnetic shock test(200G/1ms) and linear drop test(300G/2ms).

• Korean Journal of Computational Design and Engineering
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• v.17 no.4
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• pp.274-281
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• 2012

This paper proposed a control simulation method for design and verification of the transport system in an automobile assembly line based on digital manufacturing system. The design of the transport system involves two major activities: mechanical design (device specification) and electrical design (device behavior and system control). Conventionally, the simulation and emulation system of the transport system focuses on the abstract level, which mainly deals with design verification, alternative comparison, and system diagnosis. Although it can provide overall system visibility in monitoring how well it works in the process and view, its simulation models are not sufficiently realistic to be used for a detailed design or for implementation purposes. In this paper, a digital simulation model for a transport system in an automotive assembly line is constructed by adapting a digital manufacturing methodology. We use the concept of the "Virtual Probe", which transport a carrier instead of the belt of the conveyor. In conclusion, the proposed method is valuable in the process of test run in the shop floor. This method would reduce the time and effort for validating the manufacturing system and improve the productivity and integrity of the control program.

• The Journal of Korean Institute for Practical Engineering Education
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• v.2 no.1
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• pp.77-83
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• 2010

Effectiveness of the e-learning hands-on practice in the engineering education depends on the quality of the contents of which simulation is a part and the teaching strategy of the instructor. Instructors who develop and use the simulation-included e-learning content should employ various teaching and learning activities which would make online simulation practice effective. Thus, the strategy for the effective e-learning simulated practice in engineering courses should be known and used effectively. The aim of this paper is to classify the development methods of the simulations and the teaching and learning activities of the development types classified. The comparison of the teaching and learning activities leads to suggestion on teaching and learning strategy for effective use of the online simulation in engineering education.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.162-162
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• 2010

In this study, optical analysis for 100W LED safety street lighting was conducted. Experimental research on such single LED was the first undertaken. simulation modeling based on optical properties of single LED has compared single LED product also designed 100W simulation modeling has compared average road illuminance with Korean Industrial Standards for LED safety street lighting(KS C7658:2009). 100W safety street lighting (model: CE180-ST-OS) designed by simulation has been also compared between product and 100W simulation modeling, and error rates have showed average 5.6[%]. Designed 100W LED safety street lighting base on simulation modeling was proven by comparison experiments. Through the simulations and the corresponding analysis, it was found that the tested 100W LED safety street lamp had reasonable performance. Design method for LED safety Street lamps have been summarized, based on the optical analysis.