• Journal of Applied Reliability
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• v.16 no.2
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• pp.125-133
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• 2016

Purpose: The purpose of this study is to evaluate durability of platform safety step system in railway. Method: We performed finite element analysis & durability analysis of platform safety step system with VPD (Virtual Product Development) techniques and examined the durability standard & qualification life through the rig test during no failure test time in reliability qualification test. We continued to test 1 million cycles in KRS (Korea Railway Standard) for system's robust design performance. Result: FEM analysis results are 14.9MPa & 14.7MPa of pin-joint, pivot and durability analysis result is above 1 million cycles. we calculated theoretically no failure test time 855,000 cycles and through the 1 million cycles durability rig test in KRS standard we confirmed product quality. Conclusion: This platform safety step system was designed very safe in terms of a mechanical strength & durability.

• Journal of the Korea Safety Management & Science
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• v.14 no.1
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• pp.117-122
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• 2012

This paper deals with the productivity increment through construction of lean production system for automobile factory in China. This lean production system has been progressed according to 5 steps. Step 1 is the work preparation. Step 2 is the process design. Step 3 is the establishment of method to count production quantity. Step 4 is the establishment of measuring method for input and output. Finally, step 5 is the construction of flexible production system able to adapt for environment change. This lean production system is expected to obtain the productivity increment by 50% for plastic plant and reduction by 50% in inventory quantity.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.10c
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• pp.103-122
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• 2001

For prediction of ground movement per the excavation step, observational results of ground movement during the construction was very different with prediction during the analysis of design. step because of the uncertainty of the numerical analysis modelling, the soil parameter, and the condition of a construction field, etc. however accuratly numerical analysis method was applied. Therefore, the management system through the construction field measurement should be achieved for grasping the situation during the excavation. Until present, the measurement system restricted by ‘Absolute Value Management system’only analyzing the stability of present step was executed. So, it was difficult situation to expect the prediction of ground movement for the next excavation step. In this situation, it was developed that ‘The Management system TOMAS-EXCAV’ consisted of ‘Absolute value management system’ analyzing the stability of present step and ‘Prediction management system’ expecting the ground movement of next excavation step and analyzing the stability of next excavation step by‘Back Analysis’. TOMAS-EXCAV could be applied to all uncertainty of earth retaining structures analysis by connecting ‘Forward analysis program’ and ‘Back analysis program’ and optimizing the main design variables using SQP-MMFD optimization method through measurement results. The application of TOMAS-EXCAV was confirmed that verifed the three earth retaing construction field by back analysis.

• Korean Journal of Computational Design and Engineering
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• v.9 no.1
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• pp.11-18
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• 2004

CAD systems have been developed with network technology and it is needed to exchange product data among them. STEP becomes world-wide international standard to exchange CAD data among various heterogeneous CAD systems in manufacturing industrial fields. We report results to test errors that can happen when exchanging STEP files of product model through the STEP translator of different commercial CAD systems. Also the tests of Korean Character, Hangul, have been carried out. And also we report the STEP rallies held twice in Korea and several rounds abroad, and their testing results are shown as tables and graphs. The tested results can be used for exchanging product models to the next domestic STEP Rally and extended to Northeastem Asian STEP rally by steadily contacting with the organizations for Asian STEP centers such as JSTEP(Japan) and CSTEP(China). Finally we expect that the result can be used to specify STEP standardization in the field of managing product data.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.12
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• pp.1810-1816
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• 1990

Step discontinuities of microstrip lines are analyzed using the mode-matching technique based on the well-known waveguide model. Including higher-order modes, the generalized scattering matrices are obtained. Asymmetrical step discontinuities as well as symmetrical step discontinuities are analyzed. The resonance characteristics of microstrip patches are calculated by cascading two microstrip step discontinuities through a uniform microstrip line. Experimental results agree well with theroretical ones.

• Structural Engineering and Mechanics
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• v.45 no.4
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• pp.521-542
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• 2013

In this study a truss model is used for the geometrically nonlinear static and dynamic analysis of a thin shallow arch subject to snap-through. Thanks to the very simple geometry of a truss, the equilibrium conditions can be easily written and the global stiffness matrix can be easily updated with respect to the deformed structure, within each step of the analysis. A very coarse discretization is applied; so, in a very simple way, the high frequency modes are suppressed from the beginning and there is no need to develop a complicated reduced-order technique. Two short computer programs have been developed for the geometrically nonlinear static analysis by displacement control of a plane truss model of a structure as well as for its dynamic analysis by the step-by-step time integration algorithm of trapezoidal rule, combined with a predictor-corrector technique. These two short, fully documented computer programs are applied on the geometrically nonlinear static and dynamic analysis of a specific thin shallow arch subject to snap-through.

• Journal of Korea Multimedia Society
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• v.19 no.6
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• pp.1043-1051
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• 2016

In this paper, double encryption technique of binary image using random phase mask and 2-step phase-shifting digital holography is proposed. After phase modulating of binary image, firstly, random phase mask to be used as key image is generated through the XOR operation with the binary phase image. And the first encrypted image is encrypted again through the fresnel transform and 2-step phase-shifting digital holography. In the decryption, simple arithmetic operation and inverse Fresnel transform are used to get the first decryption image, and second decryption image is generated through XOR operation between first decryption image and key image. Finally, the original binary image is recovered through phase modulation.

• Journal of the Ergonomics Society of Korea
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• v.26 no.4
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• pp.103-111
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• 2007

The purpose of this study is to categorize and analyze the body shape of obese Korean men that are needed for industrial design. Using the anthropometric data that were surveyed through the 5^th Size Korea project, this study was conducted in four steps mostly through the multivariate statistical analysis. In the first step, Broca, BMI, WHR indices are used to define obesity and select obese men from Korean adults and teens. After 34 human anthropometric variables are supposed to be related to obesity were extracted through an expect survey. In the second step, a factor analysis was executed for those human anthropometric variables. Through this analysis, we obtained the human body factors that are related to the representation of obesity. Then the third step, we used a cluster analysis from the result of the factor analysis. And ANOVA analysis was also conducted to obtain the critical obese human anthropometric variables. In the final step, we found the characteristics of the body types of obese men according to clusters and ages. The body types of obese men classified in the study are expected to be applied to product design for clothing, furniture, automobile packaging, etc.

• The Journal of the Korean dental association
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• v.57 no.8
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• pp.437-447
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• 2019

Purpose: In recent years, efforts to improve the dental curriculum in South Korea have focused on a shift to outcome-based dental education based on core competencies in dentistry. So far, the field has seen various studies on the development of competencies, performance evaluation, and the importance of outcome-based education, but few studies have documented the development of such an education model. Therefore, this study develops an OBE curriculum for dentistry education and describes the development procedures and then finally this study intends to share our experience to other dental schools. Methods: This study introduces the development procedure and details of an outcome-based education model for dental education and presents the five stages of an outcome-based education model. In this study, 3 educational experts and 2 dental professor composed the TFT and developed the research method according to the ADDIE model. Step 1 is to conduct quantitative / qualitative research analysis through some survey and interview, Step 2 is to do a survey to revise competency, Step 3 is to develop a materials through consensus and participation of our professors of the dental school, Step 4 is to do some workshops, Step 5 is to prepare and conduct a outcome evaluation. Results: Step 1 is a required process for developing an educational model: the Job Analysis & Need Analysis stage. Step 2 is the Development of Outcome and Competency stage, which involves revising the competencies that are the basis of the curriculum. Step 3 is developing competency descriptions, competency levels, and evaluation criteria?the Development of Outcomes and Evaluation Standards. Step 4 is the Development of Milestones for Curriculum and Instructional Strategy, which examines the curriculum's problems and analyzes the improvements of each course. Step 5 is the Evaluating Outcomes stage, conducted based on the competencies specified by the target dental school. Conclustion: The model presented here can serve as a foundation for outcome-based education in other dental schools.

• Journal of Digital Convergence
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• v.17 no.11
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• pp.435-440
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• 2019

Recently, many musical instrument mobile apps have been released targeting normal people who can't play musical instrument at all. The reason of developing video system based on step sequencer are as follows; first, users can freely play the musical instruments; second, induce multiple users to play; and third, develop and suggest new step sequencer fused with the video. To resolve issue in video synchronization caused by sync issues when operating multiple step sequencers, the Pocket Operator of Teenage Engineering was used to realize multiply-connected step sequencer and also, the ultimate video system was developed through Mira-Web for multiple participation. In addition, it's required to make the Pocket Operator as software and receive various feedbacks to continue and complement study in order to develop the better video system.