• Journal of the Korean Society of Systems Engineering
• /
• v.14 no.1
• /
• pp.36-43
• /
• 2018

The availability of the weapon system can be analyzed through state modeling and simulation using the Markov process. In this paper, show how to analyze the availability of the weapon system and can use the Markov process to analyze the system's steady state as well as the RAM at a transient state in time. As a result of the availability analysis of tracked vehicles, the inherent availability was 2.6% and the operational availability was 1.2% The validity criterion was defined as the case where the difference was within 3%, and thus it was judged to be valid. We have identified the faulty items through graphs of the number of visits per state among the results obtained through the MPS and can use them to provide design alternatives.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.2038-2043
• /
• 2009

RAMS(Reliability, Availability, Maintainability, Safety) analyses are particularly important in the railway engineering sector and are increasingly required the specialized procedures. The RAMS analysis is performed to meet the high safety and quality standards. The RAMS standards were established in 1990s. EN 50126 of CENELEC, and IEC 62278 provide railway authorities and railway company with a procedure which will enable the implementation of a consistent approach to the management of RAMS. IEC 62278 will be often referred to in the field of railway system. This paper represents the RAMS procedure to apply to the EMU (Electrical Multiple Unit) based on the referenced RAMS standards.

• Journal of Korean Physical Therapy Science
• /
• v.26 no.1
• /
• pp.9-14
• /
• 2019

Background: Pes planus, or flat foot, causes lower limb malalignment and foot pain during walking or exercise. Therefore, a highly reliable evaluation method to accurately diagnose flat feet is necessary. This study investigated the intra-and inter-rater reliability of the navicular drop test in different postures. Design: Cross sectional study. Methods: Forty healthy volunteers performed the navicular drop test in three different combinations of non-weight-bearing and weight-bearing postures (standing/standing, sitting/sitting, and sitting/standing). Two examiners alternately performed the measurements five times in each subject, and in each posture. Significant differences in measurements were obtained among the three postures, with the highest navicular drop being observed in the sitting/standing posture. Results: Inter-rater reliability was high in the sitting/standing and sitting/sitting postures. Intra-rater reliability was high in all three postures. In the sitting/sitting and sitting/standing postures, large navicular drop values and high inter- and intra-rater reliability were observed. Conclusion: Therefore, the sitting/standing and sitting/sitting postures are recommended for use in navicular drop tests to diagnose flat feet.

• Journal of the military operations research society of Korea
• /
• v.22 no.2
• /
• pp.18-36
• /
• 1996

This paper provides a research on some design techniques of Industrial Engineering / Management Science (IE/MS) for more efficient logistics support in developing armament systems. It includes RAM (reliability, availability and maintainability) analysis techniques, decision making analysis techniques, human factors engineering techniques and logistics support analysis techniques.

• Journal of the military operations research society of Korea
• /
• v.18 no.2
• /
• pp.23-43
• /
• 1992

A Stochastic simulation model for optimal design and evaluation of the integrated weapon systems under the consideration of the RAM (reliability, availability and maintainability) and life cycle cost (LCC) was developped. This model is supposed to satisfy a need regarding the methodology of optimaldesign and performance evaluation for both developpers and users of weapon systems.

• Journal of the Korean Society of Systems Engineering
• /
• v.11 no.1
• /
• pp.49-54
• /
• 2015

The RAMS Process is the Internationally required activity to secure Reliability, Availability, Maintainability, and Safety of system which will be acquired as customer requirements. The importance are situations that have been growing gradually. Specially, When developing railway system, the needs of customer about RAMS Process has been being proposed in a variety of railroad business. Through this paper, It introduces the international standards described the RAMS Process and also presents the requirements that should have to comply with it. Furthermore, the necessary activities to get certificate of a Railway system are suggested and not only the various acquisition cases of certificate but also lessons learned by cases in the field of railway signalling system are presented.

• Proceedings of the KSR Conference
• /
• 2003.05a
• /
• pp.145-150
• /
• 2003

The safety of staff customers and of general Public in general viewed as one of the most important requirements in the urban transit. The maintenance CALS system for car of urban transit is a part of standardization and development of urban transit system, and We have been performed the establishment of maintenance CALS system from 2001 to 2005. The RAMS for management computerization system are utilized in a variety of CALS system for user's convenience and safety in maintenance. Ever since its inception though, the urban transit has searched for ways to improve reliability, availability, maintainability and safety of the railway subsystem. In this paper, This system include RAMS(reliability, availability, maintainability and safety) of the vehicles shall be enhanced in the future.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.03a
• /
• pp.779-783
• /
• 2004

First this paper introduces an advanced FADEC (Full Authority Digital Electric Control) for current and future jet engines.It is designed to realize not only stable thrust control, but also performance improvement, reliability enhancement, service life extension, etc. It can be built by using current micro-processor with high computational power and there exists no difficulties but reliability problem of the micro- processor. Next, the simulation results of SFC minimization control are shown. The target engine is a supersonic, low-bypass ratio, 2-spool, combined cycle turbofan, designated as HYPR90T, which consists of a turbo engine for under Mach 3 flight and a ram engine for over Mach 3 flight. he results can then be used for performance optimization of the engine, which plays important role in the advanced FADEC.

• International Journal of Korean Welding Society
• /
• v.3 no.2
• /
• pp.29-39
• /
• 2003

The durability and reliability of thermal barrier coatings (TBCs) play an important role in the service reliability, availability and maintainability (RAM) of hot­section components in advanced turbine engines for aero and utility applications. Photostimulated luminescence spectroscopy (PSLS) and electrochemical impedance spectroscopy (EIS) are being concurrently developed as complimentary non­destructive evaluation (NDE) techniques for quality control and life­remain assessment of TBCs. This paper overviews the governing principles and applications of the luminescence and the impedance examined in the light of residual stress, phase constituents and resistance (or capacitance) in TBC constituents including the thermally grown oxide (TGO) scale. Results from NDE by PSLS and EIS are discussed and related to the microstructural development during high temperature thermal cycling, examined by using a variety of microscopic techniques including focused ion beam (FIB) in­situ lift­out (INLO), transmission and scanning transmission electron microscopy (TEM and STEM).

• The Journal of the Korea Contents Association
• /
• v.18 no.11
• /
• pp.348-352
• /
• 2018

BioRescue ($RMIng{\acute{e}}nierie$, Marseille, France) is able to assess dynamic and static balance when a test subject stands or sits over the platform. Although previous studies have examined the reliability of other balance measurement methods, little research has been conducted on the reliability of equipment such as BioRescue. This study examined the intra-rater and inter-rater reliability of BioRescue during balance assessment. Thirty-four healthy adults participated as subjects and two physical therapists participated as examiners to determine intra- and inter-rater reliability. BioRescue was used to conduct measurements during footprint (area and pressure), Romberg, and limit of stability tests. The footprint area and limit of stability tests yielded intra- and inter-rater reliability ICC values above 0.60 in all directions. However, the footprint pressure and Romberg tests yielded values below 0.60 in all directions. BioRescue showed good inter-rater and intra-rater reliability in measurements during footprint area and limit of stability tests. However, because the values of limits of stability show the difference between experienced and unskilled, skill is required for the accuracy of the equipment.