• Journal of the Society of Naval Architects of Korea
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• v.44 no.2 s.152
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• pp.139-147
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• 2007

The ultimate goal of structural design is to find the optimal design results which satisfies both safety and economy at the same time. Optimum design has been studied for the last several decades and is being studied. in this study, an optimum algorithm which is based on the genetic algorithm has been applied to the multi-object problem to obtain the optimum solutions which minimizes structural weight and construction cost of panel blocks in ship structures at the same time. Mathematical problems are dealt at first to justify the reliability of the present optimum algorithm. And then the present method has been applied to the panel block model which can be found in ship structures. From the present findings it has been seen that the present optimum algorithm can reasonably give the optimum design results.

• The Journal of Society for e-Business Studies
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• v.16 no.3
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• pp.113-127
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• 2011

An RFID system has been widely applied in many areas over the initial SCM application. In the literature enormous RFID applications in healthcare are documented to improve patient safety, patient/provider logistics, and the efficiency of collecting data. Based on the proposed 4-layered RFID system architecture, we introduce a case that implemented an UHF passive RFID-based tracking system in an outpatient clinic. Particularly, we propose a method to process RFID data that contains noise and missing reads. The proposed method for processing unreliable RFID data is capable to locate the tag accurately and provide additional business information. We finally conclude the paper with identifying obstacles and what is necessary to ensure system reliability.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.8
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• pp.740-746
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• 2008

In this paper, robust structural design of the PEMFC stack gasket is pursued with Taguchi method by considering the noise factor in stack assembly. The study of noise problem in stacking is required to secure the safety and performance improvement of PEMFC stack. The design parameters in the Taguchi method are selected so that the structural responses are insensitive to the noise factors. In the gasket analysis, a Mooney-Rivlin strain energy function is used to consider hyperelasticity between load and displacement. By uni-axial and equi-biaxial tension tests of the gasket, the material properties are determined for the use in robust design of PEMFC gasket. The robust design of the PEMFC stack may provide structural reliability.

• Convergence Security Journal
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• v.19 no.4
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• pp.173-180
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• 2019

As the 4^th Industrial Revolution(Industry 4.0), symbolized as CPS(Cyber Physical System), spreads around the world, it is essential to establish a converged security infrastructure to secure technical stability and reliability of various cyber systems to be implemented in the future. In this study, we will investigate the phenomenon of broad convergence security industry and technology including the concept of life safety in relation to the spread of the 4^th industrial revolution, and analyze the possibility of linkage between related knowledge to promote academic-industrial cooperation necessary for the convergence of security. we would like to propose a comprehensive development policy on human resource development, technology development and policy improvement.

• International Journal of Highway Engineering
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• v.14 no.6
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• pp.93-101
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• 2012

PURPOSES : This study is to develop ISM for potential risk factor in School Zone. METHODS : Based on the literature review, the Analytic Hierarchy Process (AHP) has been used most widely. However, it is difficult to apply in practice because the AHP results have the characteristics of the independence between each element and the interlayer can not explain the interrelationship. The Network Analysis Process (ANP) is possible to analyze the relationship between the elements and the network through the feedback. But, the reliability of the analysis fall because of complicated pair of comparison, also it is difficult to solve the super matrix. In this study, the complicated relationship between each element is inquired through the Interpretive Structural Modeling (ISM). RESULTS : The methodology of ISM is developed to remove the children's potential risk factors in school zone. CONCLUSIONS : It is possible to remove the children's potential risk factors from low level to high level step by step and improve safety. Through this, risk factors can be removed from the low-level, and upper-level will automatically improve.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.12
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• pp.7-14
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• 2019

A marine turning gear controls the position of the piston-crank mechanism by rotating the flywheel of the marine engine at a low speed, which is the main auxiliary machine that enables the disassembly and maintenance of the engine. In this study, the safety factor for surface durability and tooth bending strength was improved by the design modification of the marine turning gear based on the spur planetary gear. Angular velocity, torque, and efficiency of the turning gear were measured using a reliability evaluation tester, and a multibody dynamics model for analysis corresponding to the test results was developed. Finally, it was confirmed that the design improvements improved the tooth surface damage of the sun gear in the 3^rd reduction stage.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.208-216
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• 2004

The waterhammer occured when the pumps are started or stopped for the operation or tripped due to the power failure, the hydraulic transients occur as a result of the sudden change in velocity. The field tests of the waterhammer were carried out for PanGyo booster pumping station. The PanGyo pumuing station was installed booster pump of 6 sets and in-line pump of 2 sets. The main surge suppression device was equipped with the pump control valve and the surge relief valve as auxiliary. However, the pump control valve had not early controlled in the planned closing mode, and the slamming occurred to the valve of which abruptly closed during the large reverse flow. Because the pressure wave caused by the pump failure was superposed on the slam surge, the upsurge increased so extremely that the shaft of the valve was damaged. After the addition surge suppression device was equipped with air chamber. Further more in-line pump is needed surge suppression device that the pumping station acquired the safety and reliability for the pressure surge.

• Nuclear Engineering and Technology
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• v.37 no.3
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• pp.259-264
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• 2005

This paper presents a vital area identification (VAI) method based on the current fault tree analysis (FTA) and probabilistic safety assessment (PSA) techniques for the physical protection of nuclear power plants. A structured framework of a top event prevention set analysis (TEPA) application to the VAI of nuclear power plants is also delineated. One of the important processes for physical protection in a nuclear power plant is VAI that is a process for identifying areas containing nuclear materials, structures, systems or components (SSCs) to be protected from sabotage, which could directly or indirectly lead to core damage and unacceptable radiological consequences. A software VIP (Vital area Identification Package based on the PSA method) is being developed by KAERI for the VAI of nuclear power plants. Furthermore, the KAERI fault tree solver FTREX (Fault Tree Reliability Evaluation eXpert) is specialized for the VIP to generate the candidates of the vital areas. FTREX can generate numerous MCSs for a huge fault tree with the lowest truncation limit and all possible prevention sets.

• Journal of Drive and Control
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• v.11 no.4
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• pp.61-67
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• 2014

When a manual transmission equipped car stops on an incline where the nose of the car is higher than the rear, hill-start control or hill-holder could prevent the vehicle from rolling backward as the car moves forward. The easy-hill assist valve consists of a check valve and a needle type ON/OFF solenoid valve connected in parallel; it is a hydraulic actuator that can maintain brake pressure using an electrical signal from the ECU. As the EHA valve is a safety-related component of the brake system, high reliability as well as superior dynamic performance is required for it to be applied in commercial vehicles. This paper presents the design of the EHA valve as a piece of equipment that can simulate the brake actuation pressure with a pressurizing piston. Following specific test standards, the experimental results validate the implemented functions of the test equipment, proving the test stand to be effective for the performance and endurance of the EHA valve.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.5
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• pp.498-503
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• 2010

Recently, the industrial electric customers require a digital switchgear which can improve the safety and reliability of the power supply, and the quality of electric power by on-line monitoring the electric power information based on the internet under the ubiquitous environments. Accordingly, in this paper, a industrial switch-gear prototype is designed based on the power supply method of three phase, four-line type, and then a three-phase electric management module of the digital switchgear is made for industrial electric customer system. Finally, the three-phase voltage and current measuring function of the prototype is verified from real power load test.