• Journal of Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.456-462
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• 2014

In this paper, we develop a facility management system which provides fault effect and replacement alarm function of each component for supporting effective maintenance of facility. To do this, we use weighting method to each component, calculate importance of each component, and make them to hierarchy structure using bill of materials of facility. Also, we draw fault cause and fault effect of components based on failure modes effects and criticality analysis, and define criteria of severity, occurrence and detection to get risk priority number. To apply these concepts, we develop and test the facility management system to verify its practicality. In the future, we expect the developed system to apply many domains such as maintenance of ship and offshore plant.

• The KIPS Transactions:PartD
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• v.8D no.6
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• pp.789-798
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• 2001

ITS (Intelligent Transport Systems) is comprised of a number of advanced technologies, including information processing, communications, control, and electronics. Joining these technologies to the transportation system will save lives more safely, save time, and save money more efficiently. The National ITS Architecture provides a common framework for planning, defining, and integrating intelligent transportation systems. Most ITS projects are being designed and implemented in accordance with the National ITS Architecture, a reference framework that spans all of standards activities. Recently, as software technology is rapidly improved and stabilized, there are some needs to reuse pre-developed and powerful ITS technology. ITS standardization based on components and open interfaces becomes a way to solve these reusability of current ITS technology. This paper focuses on how could we design and implement the ITS component based on the National ITS Architecture. Furthermore, design and analysis of UML (Unified Modeling Language) was made through the ATIS (Advanced Traveller Information System) component development task and this UML methodology is expected to provide a standardized model for newly developed ITS components.

• Journal of the Korean Geosynthetics Society
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• v.16 no.2
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• pp.131-138
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• 2017

In this study, the expansion and compressive strength tests of emergency restoration material were carried out to restore cavity causing ground subsidence. The expansion and compressive strength characteristics according to component ratio of main material - hardener and mix proportion of blowing agent - accelerator were analyzed based on the test results. As a result of the relationship of curing time - expansion ratio analyses, it confirmed that expansion ratio decreased with reduced curing time regardless of mix proportion of blowing agent - accelerator in main material, if component ratio of hardener increased. This means that component ratio of the main material - hardener had greatly affected the expansion ratio. The compressive strength characteristics of emergency restoration material confirmed that strength was affected by mix proportion of blowing agent - accelerator. Therefore, it is necessary to apply reasonable component ratio and mix proportion to consider the required injection time, expansion ratio and strength of restoration material, when emergency restoration in ground cavity is required.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.755-762
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• 2004

In our country, when the replacement for individual components of equipment in nuclear power plants is required, establishment of individual criteria i.e. Required Response Spectra(RRS) of seismic test/analysis for the component is very difficult because of the absence of Test Response Spectra(TRS) for the individual component to be replaced, from the existing qualification documents. In this case, it is required to perform the structural analysis for the nuclear equipment including the components to be replaced. After the structural analysis, Analysis Response Spectra(ARS) at the point of the component shall be generated and used for seismic test of the component. However, as of today, no standard program authorized for the response spectra generation by using the structural analysis exists in korea. Because of above reason, the STAR-Egs computer program was developed by using the method which calculates directly the expected response spectrum(frequency vs. acceleration type) of the selected points in the nuclear equipment with input spectrum(Required Response Spectra, RRS), based on the dynamic characteristics of the Finite Element(FE) model that is equivalent to the nuclear equipment. The STAR-Egs controls ANSYS/I-DEAS commercial software and automatically extract modal parameters of the FE model. The STAR-Egs calculates response spectrum using the established algorithm based on the extracted modal parameters, too. Reliance on the calculation result of the STAR-Egs was verified through comparison output with the result of MATLAB commercial software based on the identical algorithm. Moreover, actual seismic testing was performed as per IEEE344-1987 for the purpose of program verification by comparison of the FE analysis results.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.223-228
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• 2022

In chemical processes, unintended faults can make serious accidents. To tackle them, proper fault diagnosis models should be designed to identify the root cause of faults. To design a fault diagnosis model, a process and its data should be analyzed. However, most previous researches in the field of fault diagnosis just handle the data set of benchmark processes simulated on commercial programs. It indicates that it is really hard to get fresh data sets on real processes. In this study, real faulty conditions of an industrial polystyrene process are tested. In this process, a runaway reaction occurred and this caused a large loss since operators were late aware of the occurrence of this accident. To design a proper fault diagnosis model, we analyzed this process and a real accident data set. At first, a mode classification model based on support vector machine (SVM) was trained and principal component analysis (PCA) model for each mode was constructed under normal operation conditions. The results show that a proposed model can quickly diagnose the occurrence of a fault and they indicate that this model is able to reduce the potential loss.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.2
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• pp.178-183
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• 2022

For enhancing the flame-retardant properties of wallpapers, we developed an organic-inorganic hybrid solution with ZrSiO₄ as a functional ceramic powder, coated on non-woven fabric using dip coating, spray coating, and slot-die coating methods. Their flame retardant properties were characterized by a 45° combustion tester, which is manufactured according to the flame-retardant performance standard (KOFEIS 1001 and KS F 2819). In organic-inorganic hybrid solution, with increasing the concentration of acid-catalyst (acetic acid), the precipitation of ZrSiO₄ powders increased, and the flame retardant properties decreased. The highest flame retardant result was obtained for the solution adding 5 wt% acetic acid. The optimization of the coating method and coating number resulted in the most excellent flame-retardant properties being obtained for the non-woven fabric coated for 5 or 7 times by dip coating method, and their flame-retardant properties corresponded to class 2 flame-retardant performance of wallpapers.

• Journal of Software Assessment and Valuation
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• v.17 no.2
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• pp.47-57
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• 2021

Neuromorphic technology is proposed to complement the shortcomings of existing artificial intelligence technology by mimicking the human brain structure and computational process with hardware. NA-IDE has also been proposed for developing neuromorphic hardware-based IoT applications. To implement an SNN model in NA-IDE, commonly used input data must be transformed for use in the SNN model. In this paper, we implemented a neural coding method encoder component that converts image data into a spike train signal and uses it as an SNN input. The decoder component is implemented to convert the output back to image data when the SNN model generates a spike train signal. If the decoder component uses the same parameters as the encoding process, it can generate static data similar to the original data. It can be used in fields such as image-to-image and speech-to-speech to transform and regenerate input data using the proposed encoder and decoder.

• Korean Journal of Materials Research
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• v.32 no.12
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• pp.538-544
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• 2022

In existing ceramic mold manufacturing processes, inorganic binder systems (Si-Na, two-component system) are applied to ensure the effective firing strength of the ceramic mold and core. These inorganic binder systems makes it possible to manufacture a ceramic mold and core with high dimensional stability and effective strength. However, as in general sand casting processes, when molten metal is injected at room temperature, there is a limit to the production of thin or complex castings due to reduced fluidity caused by the rapid cooling of the molten metal. In addition, because sodium silicate generated through the vitrification reaction of the inorganic binder is converted into a liquid phase at a temperature of 1,000 ℃. or higher, it is somewhat difficult to manufacture parts through high-temperature casting. Therefore, in this study, a high-strength ceramic mold and core test piece with effective strength at high temperature was produced by applying a Si-Na-Ti three-component inorganic binder. The starting particles were coated with binary and ternary inorganic binders and mixed with an organic binder to prepare a molded body, and then heat-treated at 1,000/1,350/1,500 ℃ to prepare a fired body. In the sample where the two-component inorganic binder was applied, the glass was liquefied at a temperature of 1,000 ℃ or higher, and the strength decreased. However, the firing strength of the ceramic mold sample containing the three-component inorganic binder was improved, and it was confirmed that it was possible to manufacture a ceramic mold and core via high temperature casting.

• Journal of the Korea Society of Computer and Information
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• v.14 no.10
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• pp.225-231
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• 2009

This paper describes a new algorithm to compute and track the deformation of an isosurface component defined in a time-varying volumetric data. Isosurface visualization is one of the most common method for effective visualization of volumetric data. However, most isosurface visualization algorithms have been developed for static volumetric data. As imaging and simulation techniques are developed, large time-varying volumetric data are increasingly generated. Hence, development of time-varying isosurface visualization that utilizes dynamic properties of time-varying data becomes necessary. First, we define temporal correspondence between isosurface components of two consecutive timesteps. Based on the definition, we perform an algorithm that tracks the deformation of an isosurface component that can be selected using the Contour Tree. By repeating this process for entire timesteps, we can effectively visualize the time-varying data by displaying the dynamic deformation of the selected isosurface component.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.3
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• pp.277-286
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• 2009

A suitability of a thixotropic grout developed in this study has been examined through laboratory tests on strength, segregation, and viscosity. The thixotropic grout is a mixture of two types of liquid components. The A-liquid component consists of cement, water, and MG-A and the B-liquid component consists of scarlet, water, and MG-B. Unconfined compressive strength of specimens prepared with a prefer mix-proportion satisfied a design criteria for the backfilling of tail voids. A material segregation phenomenon under water condition was not observed in the thixotropic grout whereas it was observed in the existing silica-type grout. In addition, viscosity tests have been rallied out on the thixotropic grout to verify the capability of a long-distance delivery in the field. Both the A-liquid component and the B-liquid component maintained a viscosity of below 2,000 cP for 120 minutes. This experimental result confirms that two liquid components guarantees a long-distance delivery in tile field application.