• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.2
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• pp.71-77
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• 2020

The checklist currently used for aviation safety inspection performed by ASIs(Aviation Safety Inspectors) consists of inspection groups and multiple items, it does not have safety attribute and structured hierarchy system which required to efficiently process aviation safety analysis. On this study, categorized the domestic and foreign ASI checklist by safety attribute from ICAO recommended and presented composition of checklist for safety assurance by comparative analysis composition of domestic and foreign ASI checklist.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.311-318
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• 2003

Traffic management means the management of streams of people, vehicle and cargo. Its aim is to help creating an efficient, safe and environmentally friendly transport system. Traffic management can roughly be divided in traffic control and monitoring, traffic information and demand management. The main purpose of this thesis is providing the basis for developing the next generation train traffic management system by comparing domestic and abroad train traffic management system. The composition of this thesis has been discussed in the following order of the comparison of train traffic management system's function, the introduction of Autonomous Decentralized system, the comparison between CTC and ATOS. the comparison between the hierarchy system and Autonomous Decentralized system, the study of introduction plan of Autonomous Decentralized-type train traffic management system and conclusion.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.21-28
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• 2017

Electro-hydraulic sliding deck systems have been developed to reduce the weight for the loading of an agricultural machine. The extension length of the sliding deck was calculated according to the bed's dump angle. The optimum thickness and material were determined using a large and heavy load at acceptable angles. In addition, the degrees of freedom were calculated to obtain the input/output relationship of the system. An equation was derived using a simplified model formula for the extended length of the sliding deck according to the bed's dump angle. Also, the advance length at the maximum and minimum angles of the system was determined using numerical analysis. A down-scaled model of the system was constructed and verified by experiments. The deck was simplified to determine the material and thickness of the sliding deck and for the selection of the two representative materials. The simplified model was tested in deformation tests and stress tests with different thicknesses and materials using a structure analysis program. The analysis results show that ATOS80 is the best among the two materials for reducing the weight of the system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.5933-5938
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• 2014

In this study, the effect of varying the mixture gas during FCA welding was studied for an Atos 60 test piece. To examine the characteristics of welding, the weldability of the material was checked before welding and online monitoring was performed to examine the mechanical properties after welding. The mixture Ar 80% + $CO_2$ 20% at low speed gave very elegant beads with very little spatter. 100% $CO_2$ gave rise to high spatter generation. For Ar 80% + $CO_2$ 20%, the low current region due to the normal short circuits created spatter, which was more than double for 100% $CO_2$. This peak distribution occurred due to the instability of the arc. The tensile test result for Ar 80% + $CO_2$ 20%, Ar 90%+ $CO_2$ 10% and $CO_2$ 100% at 511MPa, 507MPa, and 469MPa showed that the yield strength was improved by 8.1 and 8.9% for 80%+ $CO_2$ 20% and Ar 90%+ $CO_2$ 10%, respectively, compared to 100% $CO_2$. The tensile test result at 622MPa, 609MPa, and 581MPa showed that the yield strength was improved by 7.0% for both the mixture gas compared to 100% $CO_2$.

• Transactions of Materials Processing
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• v.25 no.5
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• pp.301-305
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• 2016

The manual modification of stamping die has widely been used in order to reduce springback after sheet metal forming. When UHSS (Ultra High Strength Steel) is used in sheet metal forming, the die design considering springback compensation is more difficult because higher strength sheet has more springback. In this study, the optimization method was used in order to design die geometry considering springback compensation after forming of 1.2GPa UHSS. Die geometries were defined as design variables and the springback distance from the die surface was conducted as object function in optimization process. The optimized die geometry considering springback compensation was performed using finite element and optimization analysis. The simulation results such as thickness distribution and springback amount were compared with measured data using 3D optical measurement system (GOM ARGUS, ATOS). And the prediction of springback amount showed a good agreement within test results.

• The Journal of Advanced Prosthodontics
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• v.12 no.5
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• pp.299-306
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• 2020

PURPOSE. The aim of this study was to evaluate the accuracy of six recently introduced intraoral scanners (IOSs) for single crown preparations isolated from the complete arch, and to determine the effect of scanning sequence on accuracy. MATERIALS AND METHODS. A complete arch with right and left canine preparations for single crowns was used as a study model. The reference dataset was obtained by scanning the complete arch using a highly accurate industrial scanner (ATOS Core 80, GOM GmbH). Six different IOSs (Trios, iTero, Planmeca Emerald, Cerec Omnicam, Primescan, and Virtuo Vivo) were used to scan the model ten times each. The scans performed with each IOS were divided into two groups, based on whether the scanning sequence started from the right or left quadrant (n=5). The accuracy of digital impression was evaluated using three-dimensional analyzing software (Geomagic Studio 12, 3D Systems). The Kruskal Wallis and Mann- Whitney U statistical tests for trueness analysis and the One-way ANOVA test for precision analysis were performed (α=.05). RESULTS. The trueness and precision values were the lowest with the Primescan (25 and 10 ㎛), followed by Trios (40.5 and 11 ㎛), Omnicam (41.5 ㎛ and 18 ㎛), Virtuo Vivo (52 and 37 ㎛), iTero (70 and 12 ㎛) and Emerald (73.5 and 60 ㎛). Regarding trueness, iTero showed more deviation when scanning started from the right (P=.009). CONCLUSION. The accuracy of digital impressions varied depending on the IOS and scanning sequence used. Primescan had the highest accuracy, while Emerald showed the most deviation in accuracy for single crown preparations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.3
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• pp.353-359
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• 2010

For achieving economical fuel consumption, an increase in the load bearing capacity, and for environmental conservation, there is a constant demand for lightweight frames of commercial vehicles used in the transportation industry. In this study, a structural analysis of the frame of a heavy flat-bed trailer was performed to determine the optimal design of a new lightweight frame made of high-strength steel. To identify the key design parameters of the trailer frame, Taguchi's orthogonal array was used in the experiments. Using ANSYS, a commercial FEA program, the frame structure was optimized with respect to stress, deflection, and torsional stiffness by performing stress and vibration analyses. A physical model of the trailer was also built to verify the validity of the numerical analyses. Finally, an on-road fatigue test of the new lightweight frame made of the high-strength steel, ATOS80, was performed to confirm the durability of the new design.

• Biomaterials and Biomechanics in Bioengineering
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• v.3 no.2
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• pp.115-127
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• 2016

Shoulder pain, injury and discomfort are public health and economic issues world-wide. The function of these joints and the stresses developed during their movement is a major concern to the orthopedic surgeon to study precisely the injury mechanisms and thereby analyze the post-operative progress of the injury. Shoulder is one of the most critical joints in the human anatomy with maximum degrees of freedom. It mainly consists of the clavicle, scapula and humerus; the articulations linking them; and the muscles that move them. In order to understand the behavior of individual muscle during abduction arm movement, an attempt has been made to analyze the stresses developed in the shoulder muscles during abduction arm movement during the full range of motion by using the 3D FEM model. 3D scanning (ATOS III scanner) is used for the 3D shoulder joint cad model generation in CATIA V5. Muscles are added and then exported to the ANSYS APDL solver for stress analysis. Sensitivity Analysis is done for stress and strain behavior amongst different shoulder muscles; deltoid, supraspinatus, teres minor, infraspinatus, and subscapularies during adduction arm movement. During the individual deltoid muscle analysis, the von Mises stresses induced in deltoid muscle was maximum (4.2175 MPa) and in group muscle analysis it was (2.4127MPa) compared to other individual four rotor cuff muscles. The study confirmed that deltoid muscle is more sensitive muscle for the abduction arm movement during individual and group muscle analysis. The present work provides in depth information to the researchers and orthopedicians for the better understanding about the shoulder mechanism and the most stressed muscle during the abduction arm movement at different ROM. So during rehabilitation, the orthopedicians should focus on strengthening the deltoid muscles at earliest.