• Journal of Engineering Education Research
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• v.26 no.1
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• pp.3-11
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• 2023

The purpose of this study is to develop Raspberry Pi-based CanSat instruction materials for liberal arts classes to be used in university space education. The educational satellite simulation program is developed by applying the ADDIE program consisting of analysis, design, development, execution, and evaluation of 15 lessons per semester. The usefulness of the instruction materials is evaluated by a validity test of a total of 6 experts. The proposed materials are applied to 100 college students from various majors. To analyze the impact on creative problem-solving ability, a questionnaire is conducted before and after class, and as a result, it is confirmed that there is a significant improvement in all areas after class. The class satisfaction survey is conducted for a total of 10 questions, and the average score is 4.41 out of 5, which is high. In conclusion, the proposed instruction materials make it possible to achieve successful space education using Raspberry Pi and improve creative problem-solving ability in universities.

• Journal of Biosystems Engineering
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• v.27 no.3
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• pp.185-194
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• 2002

The objective of this study was to analyze a stability of sideways overturning of a forwarder developed by the Forestry Research Institute. The stability analysis was conducted using a multibody dynamic analysis program. VisualNastran Desktop. A solid model of the forwarder was constructed and its physical properties such as mass, mass center and mass moment of inertia were determined on 3D CAD modeler of the Solid Edge 8.0. 3D simulations of sideways overturning of the forwarder were also performed on the Visual Nastran using the solid model when it traveled across the slope and traversed over an up-hill side obstacle. Stability comparison between a bogie-wheeled and a 6-wheeled forwarders was also made and found that the bogie-wheeled forwarder was more stable than the 6-wheeled one on slopes. The safety speeds of the forwarder predicted by the simulation under various conditions can be used as a guideline for safe operations of forwarders in mountainous area. The technique of using a solid model for the sability analysis can also be applied successfully to other vehicles like agricultural tractors, loaders and construction equipments.

• 연구논문집
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• s.30
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• pp.101-110
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• 2000

Weft insertion mechanism is for completing the structure of yarn and weft yarn and its driving method is screw type. In the high speed rapier loom, weft yarn is thrown by insert rapier and carrier rapier into the shed which make divide two parts of upper part ant lower part for warp yarn. It is possible for this mechannism to reduce the size of rapier and wheel, and directly connected to the main shaft without gear belt. Therefore, exact rapier motion through realization of arbitrary acceleration diagram requested rapier and optimal design for high speedization and operating rate increasing are necessary. In this study, with a view to exact system analysis for understanding of overall trace and high speedization of rapier loom through computer simulation. we report not only deduction of displacement, velocity, and acceleration components of rapier for analysis theory establishment, of weft insertion mechanism and exact motion induction according to screw rotation, but also development of simulation program for realization these on the monitor.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.76-79
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• 2008

In this work wood crib burning behaviors have been simulated by using the FDS(Fire Dynamic Simulator) program. Wood cribs are regularly stacked arrays of wood sticks, and available for the performance rating of fire-extinguishers. On the basis of an angle iron supporter 26 layers of wood sticks have been stacked up. Each layer consists of 5 or 6 wood sticks which are placed in parallel, with a constant distance, and in alternating rows. They are laid between the horizontally adjacent sticks at the before last layer. The wood crib is ignited instantaneously by an amount of burning gasoline below. A comprehensive simulation of such a practical sophisticated combustion is still too difficult to realize with any currently available computer, although the performance of modern processors is getting better everyday. We could carry it out here through parallel computing on the HPC(High Performance Computing) cluster as the feasible alternative. At last the validation has been executed by means of temperature distribution data measured by the thermal video camera.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.3
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• pp.94-100
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• 1999

In this paper, we are implemented the courseware targets to the integrated a digital system analysis, a design theory, and a hardware description language training and a logic analysis. This paper consists of two subjects. One is that the learning of a digital system analysis, that of a design theory, and the training of a hardware description language is simultaneously performed. The other is that the experiment of courseware. To learn the hardware description language, the explanation using sound or moving images, setting-up of a simulation or a synthesis program, and simulating are executed on a courseware. And also, we proposed an integrated systems for the hardware description language and a logic synthesis. Also, The reliablity of the tool was verified to be preyed an efficient operation of an implemented digital system courseware tool by korea computer research association.

• Elastomers and Composites
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• v.52 no.4
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• pp.317-325
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• 2017

Molding conditions can be described as factors that determine the quality of a product obtained from injection molding. Many studies have been performed on the injection molding pressure, injection temperature, packing pressure and other molding conditions related to part quality. However, the most accessible factor among the adjustable molding conditions during actual injection is the injection speed. In this study, we simulated the variation of the physical quantity according to injection speed and performed experiments to understand the effect of injection speed on the actual product. A CAE analysis program (Moldflow) was used to simulate and analyze the results using PC and PBT for two models. In order to compare these results with the experimental results, an actual injection molding was performed for each injection speed, and the correlation between simulation and injection molding, especially for the shrinkage of the molded article, was discussed.

• Elastomers and Composites
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• v.52 no.4
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• pp.309-316
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• 2017

In injection molding, the quality of an injection molded product varies greatly depending on the molding conditions. Many researche studies have been conducted on the quality analysis of molded parts according to the molding conditions such as injection pressure, injection temperature, and packing pressure. However, there have not been many studies on the V/P switchover timing. It is known that when a large pressure is applied to a cavity in the packing phase, the cavity pressure is most affected by the packing pressure. In addition, depending on the position (timing) of the packing pressure, it can have a direct influence on quality based on the shrinkage and dimensions of the molded parts. In this study, the change in pressure profile in the cavity according to the V/P switchover position is confirmed. A CAE analysis program (Moldflow) was used to simulate and analyze two models using the PC and PBT materials. In order to compare these results with the actual injection molding results, injection molding was performed for each V/P switchover position, and the correlation between simulation and experiment, especially for the shrinkage of molded parts, was evaluated.

• Advances in Energy Research
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• v.5 no.4
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• pp.289-304
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• 2017

Large glazed surfaces and windows become common features in modern buildings. The spread of these features was influenced by the dependence of designers on mechanical and artificial systems to provide occupants with thermal and visual comfort. Countries with hot summer and cold winter conditions, like Jordan, require maximum shading from solar radiation in summer, and maximum exposure in winter to reduce cooling and heating loads respectively. The current research aims at designing optimized double-positioned external shading device systems that help to reduce energy consumption in buildings and provide thermal and visual comfort during both hot and cold seasons. Using energy plus, a whole building energy simulation program, and radiance, Lighting Simulation Tool, with DesignBuilder interface, a series of computer simulations for energy consumption and daylighting performance were conducted for offices with south, east, or west windows. The research was based on comparison to determine the best fit characteristics for two positions of adjustable horizontal louvers on south facade or vertical fins on east and west facades for summer and winter conditions. The adjustable shading systems can be applied for new or retrofitted office or housing buildings. The optimized shading devices for summer and winter positions helped to reduce the net annual energy consumption compared to a base case space with no shading device or with curtains and compared to fix shading devices.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.2 s.308
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• pp.73-81
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• 2006

This paper proposes the improved orthogonal projection method as a new technique advancing the performance of the acoustic echo canceller. Comparing with the widely used NLMS adaptive algorithm which is simple and stable, it shows that this method has the improvement of the convergence speed for signals with the large auto-correlation, and has small computational quantities. In order to testify performances of the orthogonal projection method whom this paper proposes, we have coded a simulation program md executed computer simulations. We observed convergence curves by using two adaptive algorithm for noises and speeches. From simulation results for two input signals, the proposed method shows the high ERLE and the fast convergence and the stable operation in case of using speeches as well as noises.

• KSBB Journal
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• v.10 no.1
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• pp.97-104
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• 1995

A computer simulation of biochemical process was carried out using Macintosh-based BioDesignerTM developed at Bioprocess and Engineering Center(BPEC) of MIT. Based on the assumptions and flask culture experiments, a porcine growth hormone (PGH, Porcine Somatotropin) production process was simulated by a two-stage continuous culture. The economical and sensitivity analyses were evaluated for the scale-up production of PGH. A high return on investment (ROI, 104%/year) suggested that the process be profitable. However, sensitivity analysis indicated that ROI was dependent on the yield of PGH, selling price, dose and the achievement of projected market penetration.