• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.52-60
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• 1999

By implementing the Systems Engineering process for the aircraft preliminary design, functional analysis study is performed, hence Functional Interface Data Flow(FIDF) and Functional Flow Block Diagram(FFBD) are generated. Based on FIDF and FFBD, allocable and non-allocable design/performance/RM＆S requirements are allocated to the appropriate levels. Weight and cost tracking and design margin management methodologies are studied and implemented for the balanced aircraft design.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1541-1544
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• 2003

In this study, embodying reliability block diagram based on the web and reliability analysis technology are developed. RBD(reliability Block Diagram) represents the functional relation between elements in any product. Among relations between elements. there are serial, parallel, bridge, and stand by, etc. Advantages of developed system are integrated datum about reliability (NPRD, EPRD, MIL-HDBK 217F, NSWC. OREDA. Bellcore, and domestic institutes & companies datum). graphic user interface for convenience, and the various service analyzes the failure history data of parts.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.145-149
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• 1987

The input-output relation for nonlinear systems can be explicitly represented by the Voltera functional series and it is characterized by the Volterra Kernels. A block diagram reduction method is introduced to determine the Volterra Kernels for the nonlinear systems represented by nonlinear differential equations. Degree of nonlinearity is defined and analyzed for the analysis of nonlinear systems.

• Journal of the Korean Society of Safety
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• v.39 no.1
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• pp.16-26
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• 2024

This study aims to introduce a method for risk assessment analysis aimed at preventing electrical fires within the manufacturing industry. Initially, we provided a functional block diagram illustrating the electrical equipment employed in various processes within a food manufacturing company in Chungcheongbuk-do. Subsequently, we categorized the components of each machine outlined in the functional block diagram and determined the priority of failure for each classified component. Upon implementing the model in the frying process of the food manufacturing company, specific components, including MC, motor, mixer heater, electric wiring, and terminal block, exhibit a risk priority number (RPN) of 40 or higher. This identified an electrical issue within the manufacturing process and environment. Consequently, we propose a methodology to identify latent failure modes that could escalate into fires or systemic issues if not promptly addressed. It is essential to note that while the FMEA presented in this study may not immediately impact food manufacturing, its applicability extends to various workplaces.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.255-261
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• 2007

In this paper we introduce the method, procedure and result of RAM prediction for interlocking system which is applied for AREX signaling system. For RAM prediction, we breakdown the interlocking system to the LRU level and select the LRUs of which failure can cause the service delay. The prediction of reliability is based on the Reliability Block Diagram which is the functional diagram composed of selected LRUs and finally, the availability of interlocking system is estimated from the combination of reliability and maintainability.

• Journal of the Korean Society for Railway
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• v.8 no.5
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• pp.434-438
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• 2005

In this paper, as the first step to assess and enhance the reliability of Korea High Speed Train, an electric traction system is selected and reliability analysis is carried out. The electric traction system is classified into subsystems and functional block diagrams and reliability block diagrams are drawn. Expressions for evaluating the reliability are derived and Mean Kilometer Between Service Failure is calculated using the trial track test results. The calculation results show reliability growth of the proposed system.

• Macromolecular Research
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• v.10 no.6
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• pp.359-364
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• 2002

A series of PLA-PEO-PLA triblock stereo-copolymers with varying PLA/PEO and L-DL-LA ratios were synthesized via ring opening pelymerizations. Aqueous solutions of these copolymers undergo thermo-responsive phase transitions as the temperature monotonically increases. Further study shows that there is a critical gel concentration (CGC), and also lower and upper critical gel temperatures (CGTs), at which the thermo-responsive phase transition occurs. The CGC and CGTs are affected by various factors such as block length, as well as the compositions of the PLA blocks and of the additives. In particular, the changes in the phase diagram produced by varying the L-/DL-LA ratio in the PLA blocks were determined to be mainly due to consequent stereo-regularity changes in the PLA blocks.

• Korean Journal of Construction Engineering and Management
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• v.22 no.2
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• pp.21-30
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• 2021

The existing construction industry is classified into industries with low productivity compared to other industries. In order to solve the decline in productivity in the construction industry, the world is focusing on off-site construction (OSC), which is about 40% more productive than existing construction methods. This high productivity is possible because the three stages of production, transport to the site, and site assembly are consistently maintained in a continuous flow. This study conducted a functional survey through literature review, preliminary field survey, questionnaire, and expert interview. The surveyed function were classified into five categories: convenience, flexibility, manageability, communication, and safety, and the functional characteristics of flexibility, manageability, and communication were high. Because of the change according to the construction progress, the production schedule of the factory, and the variety of transportation time required. Finally, A functional block diagram was developed based on the 15 functions corresponding with an average score of 4 or more in the surveyed function score result. If the OSC transport system is established through this study, It can contribute to a successful construction OSC project and increase productivity.

• Proceedings of the Korean Reliability Society Conference
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• 2004.07a
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• pp.233-237
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• 2004

In this paper, to assess and enhance the reliability of Korea High Speed Train, electric traction system is selected and reliability analysis is carried out. The electric traction system is classified into subsystems and the functional block diagram and the reliability block diagram are drawn. Expressions to calculate the reliability are deduced and Mean Kilometer Between Service Failure is calculated using the trial test results on the track. Calculated results show reliability growth of the electric traction system.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.3
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• pp.315-321
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• 1988

The input-output relation for nonlinear systems can e explicitly represented by the volterra functional series and it is characterized by the Volterra kernels. A block diagram reduction method is proposed to determine the Volterra kernels for nonlinear differential equations and is compared with the direct substitution techniques. The former method can significantly reduce the computational complexity. A degree of nonlinearity is defined and analyzed for the analysis of nonlinear systems.