• Journal of Drive and Control
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• v.16 no.3
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• pp.33-41
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• 2019

This study presents the development of a lifetime test bench for the strain wave reducer which is a precision gear reducer of the robot to realize fault diagnosis and failure prognostics. To this end, the lifetime test bench was designed to detect the vertical forward/reverse direction rotation load. Through the lifetime test bench, it is possible to apply the same load spectrum from robot working scenarios. We developed a data integration gateway for fault data collection. Through the development of dedicated software for fault diagnosis and failure prognostics, these data from vibration, noise and temperature sensors were collected and analyzed along with the operation of the lifetime evaluation.

• Journal of Drive and Control
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• v.16 no.2
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• pp.51-58
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• 2019

In this study, flow analysis and dehumidification experiment were conducted on hollow fiber membrane module to determine the dehumidification characteristics of its various configurations. A quantitative analysis of the CFD for four different models with a temperature of $30^{\circ}C$ and 30%RH inlet humidity was conducted. Each model has different shape parameters i.e. the number of hollow fiber membranes and the presence or absence of baffles. After comparison between the flow analysis results and dehumidification experiment results, the percentage error was found to be approximately 2%. The moisture removal rate for each model was calculated using flow analysis data. It was found that the moisture removal rate of refined model with three baffles and eight hollow fiber membranes was highest among the four modeled modules of hollow fiber membrane one, i.e. about 60%.

• Journal of Software Engineering Society
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• v.25 no.2
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• pp.29-34
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• 2012

Quality control in medical is getting very important issue so that the importance of CDS(Clinical Decision Support) System has been increased. Local clinics as well as big hospitals are required to implement the CDS System. But the cost and complexity of CDS system implementation is so high since many different activities including knowledge authoring, software development, and integrating the legacy system are necessary. In this paper, we suggest the CDS system architecture to be sharable and interoperable and evaluate the availability and efficiency of this architecture.

• Journal of Drive and Control
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• v.15 no.4
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• pp.48-54
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• 2018

The hydraulic servo actuator has always operated very precisely with high frequency and small displacement, and is used continuously for a long time. The hydraulic servo actuator of the test equipment used in the accelerated life test in order to guarantee the service life of the automotive parts failed earlier than the products before finishing the test. This study performed an analysis on the cause of the failure of the hydraulic servo actuator used in the test equipment, changed the design of the actuator to solve the root cause of the main failure mode, and developed the improved servo actuator. Based on above process, this study established a better performances and longer lifetime of the servo actuator after testing.

• Journal of Drive and Control
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• v.15 no.4
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• pp.74-80
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• 2018

A damper is a hydraulic device designed to absorb or eliminate shock impulses which is acting on the sprung mass of vehicle. It converting the kinetic energy of the shock into another form of energy, typically heat. In a vehicle, a damper reduce vibration of car, leading to improved ride comfort and running stability. Therefore, a damper is one of the most important components in a vehicle suspension system. Conventionally, the design process of vehicle suspensions has been based on trial and error approaches, where designers iteratively change the values of the design variables and reanalyze the system until acceptable design criteria are achieved. Therefore, the ability to tune a damper properly without trial and error is of great interest in suspension system design to reduce time and effort. For this reason, a many previous researches have been done on modeling and simulation of the damper. In this paper, we have conducted optimal design process to find optimal design parameters of damping force which minimize a acceleration of sprung mass for a given suspension system using genetic algorithm.

• Smart Structures and Systems
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• v.24 no.3
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• pp.319-332
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• 2019

Structural health monitoring (SHM) is of great importance to super high-rise buildings. The Shanghai Tower is currently the tallest building in China, and a complete SHM system was simultaneously constructed at the beginning of the construction of the tower. Due to the variety of sensor types and the large number of measurement points in the SHM system, an online automatic structural health assessment method with few computations and no manual intervention is needed. This paper introduces a structural health assessment method for the Shanghai Tower that uses the coefficients of an autoregressive (AR) time series model as structural state indicators. An analysis of collected data indicates that the coefficients of the AR model are affected by environmental factors, and the principal component analysis method is used to remove the influence of environmental factors. Finally, the control chart method is used to track the changes in structural state indicators, and a plan for online automatic structure health state evaluation is proposed. This method is applied to long-term acceleration and inclination data from the Shanghai Tower and successfully identifies the changes in the structural state. Overall, the structural state indicators of the Shanghai Tower are stable, and the structure is in a healthy state.

• Journal of Korean Elementary Science Education
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• v.38 no.3
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• pp.426-438
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• 2019

The purpose of this study is to help science gifted students construct posters after conducting scientific open inquiry. To this end, we analyzed 25 posters written by elementary science gifted students and extracted deficient aspects from the posters. Based on this, a checklist consisting of 17 items in 5 categories was developed to help students construct posters. By applying the developed checklist to the evaluation of 14 posters constructed by science gifted students in middle school, the correlations between evaluators and Cohen's kappa values showed high reliability. In addition, by comparing the evaluation results of the seven 7 posters constructed using the checklist with the evaluation results of control group, a significant difference at the level of p<.01 was obtained, therefore, the usefulness of the checklist was confirmed. Students who used checklists responded positively, including that the checklist helped them to recognize deficiencies in their inquiry and to construct posters systematically without omitting key items of the posters. Finally, additional considerations were discussed for the preparation and presentation of the students' posters.

• Proceedings of Korean Society of Archives and Records Management
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• 2019.05a
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• pp.55-60
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• 2019

The cloud records management system has the following problems. It has not been accompanied by a change in the legislative system and has not been exploited the benefits of cloud technology. In addition, it has not been considered for changes after system construction. To solve this problem, the contents of the Fourth Industrial Revolution should be reflected in the improvement of the legislative system and the long-term development strategy of the national archives system. A fundamental review of the records management system is also required, and in the process of e-government, the National Archives should act as a pan-government records management control tower.

• Journal of Korean Society for Quality Management
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• v.47 no.1
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• pp.151-162
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• 2019

Purpose: This study is in order to secure high quality of military supplies, it is important to secure design quality in the development phase. I will review how to establish a quality assurance system in the development phase based on the author's seminar presentation contents and application example of Hanwha Systems Co., Ltd. Methods: To guarantee design quality in the development phase, in 2002, quality assurance system that is adequate for SQA(Software Quality Assurance)'s requirements of CMM(Capability Maturity Model) was conduct. In 2009, based on the CMMI(Capability Maturity Model Integration) Level 5, there has been continuous and reenforced quality assurance activities. Results: By suggesting the construction and a case study on application of R&D quality assurance, it would be helpful for companies aiming to construct or enhance quality assurance system. Conclusion: To secure high quality for military supplies, a development QA system should be established to secure quality in the development phase. In addition, Total life cycle QA system for development, mass production and operation phase should be reestablished.

• Journal of Drive and Control
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• v.16 no.1
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• pp.7-13
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• 2019

The objective of this study was to present a damped pneumatic suspension, a bike fork suspension, which can adapt itself to incoming road excitations is presented in this paper. It consists of a hydraulic damper and a pneumatic spring in parallel with a linear spring. The study also proposed a variable and switchable orifice, in the hydraulic damper, to select appropriate damping property. Hydraulic-pneumatic circuit model for the bike fork suspension was established based on AMESim, in order to predict its performance. In addition, elastic-damping characteristics of the fork such as spring constant and viscous damping coefficient were computed and compared, for validation, with those evaluated by experiment using the universal test machine. Through simulation analysis and test, it was established that the hydraulic-pneumatic circuit model is effective and practical for development of future MTB suspensions.