• Journal of the Korean Society of Systems Engineering
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• v.14 no.2
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• pp.49-57
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• 2018

The main objective of this paper is come up with methodology approach for FPGA-based system in verification and validation lifecycle regarding software reliability using system engineering approach. The steps of both reverse engineering and re-engineering are carried out to implement an FPGA-based of safety critical system in Nuclear Power Plant. The reverse engineering methodology is applied to elicit the requirements of the system as well as gain understanding of the current life cycle and V&V activities of FPGA based-system. The re-engineering method is carried out to get a new methodology approach of software reliability, particularly Software Reliability Growth Model. For measure the software reliability of a given FPGA-based system, the following steps are executed as; requirements definition and measurement, evaluation of candidate reliability model, and the validation of the selected system. As conclusion, a new methodology approach for software reliability measurement using software reliability growth model is developed.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.11
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• pp.37-43
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• 2018

According to the evaluation of basic properties and mechanical characteristics of polymer cement mortars that contain re-dispersible type polymer, in the case of fresh mortars, flow and air content were increased due to the dispersion action of entrained air and surfactant with an increase of polymer addition ratio. In the case of mortars after hardening, flexural strength, bonding strength, absorption rate and carbonation resistance were improved due to the increased union and waterproof characteristics of internal structures as a result of the formation of polymer film.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.3
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• pp.35-41
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• 2019

In this study, the fire resistance performance of polymer cement mortars which are used as a representative repair material for section restoration, is evaluated and residual bond strength is measured by considering unity with concrete. According to the evaluation of fire resistance performance of re-emulsification type polymer cement mortars, residual compressive strength was drastically decreased according to heating temperatures with an increase of polymer addition rate, and this seems to be attributable to the application of polymer film. In addition, an explosion phenomenon occurred frequently with an increase of addition rate, so this should be considered when selecting repair materials and processing.

• Geomechanics and Engineering
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• v.31 no.6
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• pp.623-635
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• 2022

This paper presents the re-evaluation of existing piezocone penetration test (CPTu)-based shear wave velocity (V_s) equations through their application into well-documented data obtained at nine sites in six countries. The re-evaluation indicates that the existing equations are appropriate to use for any specific soil, but not for various types of clays. Existing equations were adjusted to suit all nine clays and show that the correlations between the measured and predicted V_s values tend to improve with an increasing number of parameters in the equations. An adjusted equation, which comprises a CPTu parameter and two soil properties (i.e., effective overburden stress and void ratio) with the best correlation, can be converted into a CPTu-based equation that has two CPTu parameters and depth by considering the effect of soil cementation. Then, the developed equation was verified by application to each of the nine soils and nine other worldwide clays, in which the predicted V_s values are comparable with the measured and the stochastically simulated values. Accordingly, the newly developed CPTu-based equation, which is a time-saving and economical method and can estimate V_s indirectly for any type of naturally deposited clay, is recommended for practical applications.

• Korean Journal of Environment and Ecology
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• v.37 no.6
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• pp.484-498
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• 2023

This study aimed to analyze the appropriateness of the criteria and methods of the feasibility study for national park re-planning. The rate of 'release area' was derived at a lower rate in the absolute evaluation (the second) than the relative evaluation(the third) Seoraksan and Juwangsan National Parks as well as Gayasan National Park. Despite the third evaluation method aiming to maintain park area through retention by setting the areas available for release as 10% rather than applying release, it was found that the absolute evaluation method did not derive more areas available for release. When the second and third ecology-based assessments were applied to study sites, both second and third ecological-based assessments showed that the actual release areas were not reflected in the extraction in 2011. Consequently, it was found that the ecological-based assessment was only a means of assistance instead of a means of critical decision-making for determining the release area. From the district adjustment of the park planning easibility study, it can be determined that interactive exchange and priority application of release criteria as external factors acted more significantly.

• Journal of Industrial Technology
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• v.26 no.B
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• pp.21-28
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• 2006

A diesel truck of 1 ton is re-powered by a gasoline engine and the fuelling system of gasoline engine modified to gasoline/CNG bi fuel system. The engine characteristics such as fuel economy and power are evaluated by driving rest, sloping test and dynamometer. The driving test prove the driving cost is saved by 55% and the maximum speed is raised by 13%, which is mainly due to the higher calorific value of CNG. The sloping test is done on the road of which slope is 15%. The truck shows the mean velocity of 88km/h, which means that a re-powered truck is working fine. The BHP are measured by dynamometer. The power and torque produced by a re-powered truck are reduced by 13% and 14% respectively from the power of gasoline engine. The BHP reduction is one of main problems which one has to solve in near future.

• KIEAE Journal
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• v.13 no.2
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• pp.77-84
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• 2013

Schools are one of favorable public buildings for Renewable Energy(RE) systems due to site conditions and their energy demand profiles(e.g. daytime-based use of hot water and heating/cooling). Although the government encourages schools to be equipped with RE systems, the adoption of RE systems in existing energy supply systems faces technical and financial barriers. For example, when installing a RE-based combination system(RECS) to meet the energy demand at various school scales, identifying cost effective combination of capacities of the RECS is not trivial since it usually requires technically intensive work including detailed simulation and demand/supply analysis with extensive data. This kind of simulation-based approaches is hardly implementable in practice. To address this, a simpler and applicable decision-supporting method is suggested in this study. This paper presents a simplified model in support of decision-making for optimal capacities of RECS within given budget scales and schools sizes. The proposed model was derived from detailed simulation results and statistical data. Using this model, the optimal capacities of RECS can be induced from the number of classes in a school.

• Korea Journal of Hospital Management
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• v.16 no.4
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• pp.111-130
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• 2011

The purpose of this study is to find moderating effects of re-use intention by trust factors between patients satisfaction and hospital images. Survey a general hospital in Seoul was performed, and a total of 202 questionnaires has been analyzed. Result of multiple regression analysis are verified moderating effects by trust factors with hospital image and re-use intention(F=8.223**). And patient satisfaction and re-use intention are verified moderating effects by trust factors(F=4.255*). In addition, classify them into high trust group and low trust group by median split method, even if there are felt the equal level of satisfaction or image that high trust group will be re-visit the hospital better than low trust group. As a result, trust factors must consider different level from satisfaction or image, it is necessary that hospitals will be prepare to improve the trust.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.40-41
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• 2006

In this work, we developed the 0-3 type piezoelectric composite to incorporate the advantages of both ceramic and polymer. The PVDF-PZT composites were fabricated with various mixing ratio by 3-roll mi11 mixer. The composite solutions were coated on ITO bottom-electrode deposited on PET (polyethylene terephthalate) polymer film by the conventional screen-printing method. After depositing the top-electrode of silver-paste, 4kV/mm of DC field was applied at $120^{\circ}C$ for 30min to poling the 0-3 composite film. The value of $d_{33}$ was increased as the PZT weight percent was increases. But the $g_{33}$ value showed the maximum at 65 wt% of PZT powder.

• The Journal of Internal Korean Medicine
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• v.37 no.2
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• pp.283-292
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• 2016

Objective: Acne scarring is the most common sequela after dermal inflammation caused by acne. Many methods are currently used to treat acne scarring; doctors using traditional Korean medicine have also attempted to treat acne scarring in a new way that was developed from traditional methods. This study examines the effectiveness of re-cell therapy.Method: Eleven patients with various types of acne scars were treated by re-cell therapy. We used the global acne scarring classification (GASC) and ECCA (from the French “echelle d’evaluation clinique des cicatrices d’acne”), both of which are generally used to measure and grade the degree of acne scarring.Results: As a result of the treatment, the conditions of all patients were conspicuously improved in both scales. The GASC scores of the patients changed from grade 19.6±10.4 to grade 4.9±3.3 (p=0.001), and the ECCA scores changed from grade 120.9±28.7 to grade 41.8±18.3.Conclusion: Re-cell therapy showed effectiveness in treating acne scarring and could be applied in clinical cases.