• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.6
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• pp.681-687
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• 2014

Nuclear industries have faced unfavorable circumstances such as an obsolescence of the instrumentation and control system, and therefore nuclear society is striving to resolve this issue fundamentally. IEC and IAEA judge that FPGA technology is a good replacement for Programmable Logic Controller (PLC) of Nuclear Instrumentation and Control System. FPGAs are currently highlighted as an alternative means for obsolete control systems. Because the main function inside an FPGA is initially developed as software, good software quality can impact the reliability of an FPGA-based controller. Therefore, it is necessary to establish a software development aspect strategy that enhances the reliability of an FPGA-based controller. In terms of software development, HDL-Programmed Device (HPD) Development Life Cycle is applied into FPGA-based Controller. The burn-in test and environmental(temperature) test should be performed in order to apply into nuclear instrumentation and control system. Therefore it is ensured that the developed FPGA-based controller are normally operated for 352 hours and 92 hours in test chamber of Korea Institute of Machinery and Materials (KIMM).

• Journal of the Korea Institute of Building Construction
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• v.14 no.5
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• pp.423-432
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• 2014

The aim of this study to propose an efficient method in selecting the type of new and renewable energy applied in at the planning phase of buildings. This study applied geothermal energy facilities with high adaptability to buildings. This study considered the energy reduction and reduced cost by comparing the values with the energy consumption before applying of geothermal energy facilities. In order to propose more reliable criteria of economic evaluation, maintenance costs reflecting the replacement cycles and initial construction costs by drawings and specifications for installation facilities for practical geothermal energy based on construction statement for life-cycle cost analysis. The results will help to effectively select economic types of facilities for new and renewable energy of the planning phase of buildings.

• Journal of the Korea Institute of Building Construction
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• v.19 no.5
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• pp.391-399
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• 2019

This study reviewed the possibility of recycling into exhausted aggregate resources in Korea as a means of utilizing coal gasification slag(CGS) from integrated gasification combined cycle(IGCC) while being commissioned in order to introduce the new system to Korea. In other words, in order to solve the problem of insufficient aggregate resources, CGS generated by IGCC as a residual aggregate for concrete secondary products, which is an empty mortar, was considered to replace CGS in the range of 0 to 100 % for mixed residual aggregate mixed with crushed sand A(CSa) of good quality and sea sand(SS) of deep particles, which are the most commonly used in the domestic construction industry. According to the study, replacing CGS with CSa or crushed sand B(CSb)+SS by 25 % to 50 % resulted in good results in the aspect of the granularity of the aggregate and the workability and compressive strength of cement mortar, which were found to be usable.

• Corrosion Science and Technology
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• v.14 no.2
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• pp.59-63
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• 2015

Airless spray which is widely used for painting to ship blocks and hull sides is the coating method for attaching atomized paint material to the substrate using spray tip nozzle with compressed air. When the paint material which has high solid contents such as epoxy primer paint is atomized by passing through spray tip nozzle with high pressure, the nozzle composed of tungsten carbide(WC) undergoes the erosive wear, leading to widening of nozzle hole. The deformation of nozzle hole induces improper spray pattern and coating failures such as finger pattern and sagging because the conditions of spray pump pressure and paint flow rate for developing full spray pattern are changed. In this study, an appropriate replacement cycle of spray tip was predicted by measuring the erosive wear tendency as increasing the spraying time of epoxy primer paint.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.6
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• pp.197-207
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• 2020

This study aims to examine the influence of attitudes on customers' intention to participate in online fashion sharing. A framework was proposed to investigate the relationships between consumer motivation, consumer attitude, and purchase intention in the manner of adopting a fashion-sharing platform. Consumer motivations are divided into three categories: utilitarian, hedonic, and ecological. The moderating effects of product replacement cycle (PRC) on consumer attitude and purchase intention are also investigated. Data collection was developed using a web-based survey where 180 consumer respondents from South Korea participated. The results of our analysis indicate that consumers' hedonic and ecological motivations are positively related to favorable consumer attitudes, even when consumers' utilitarian motivation is denied. Consumer attitude is also positively related to purchase intention in the fashion-sharing platform. A moderating effect of PRC is recorded between consumer attitude and purchase intention based on high and low PRC, as well as the effect of ecological motivation and consumer attitude on high PRC. This study enhances knowledge of consumer motivational factors in a fashion-sharing platform and provides insights for service providers to help them improve their target marketing.

• BMB Reports
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• v.51 no.11
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• pp.563-571
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• 2018

Colorectal cancer (CRC), the third most common cancer in the world, has no specific biomarkers that facilitate its diagnosis and subsequent treatment. The miRNAs, small single-stranded RNAs that repress the mRNA translation and trigger the mRNA degradation, show aberrant levels in the CRC, by which these molecules have been related with the initiation, progression, and drug-resistance of this cancer type. Numerous studies show the microRNAs influence the cellular mechanisms related to the cell cycle, differentiation, apoptosis, and migration of the cancer cells through the post-transcriptionally regulated gene expression. Specific patterns of the upregulated and down-regulated miRNA have been associated with the CRC diagnosis, prognosis, and therapeutic response. Concretely, the downregulated miRNAs represent attractive candidates, not only for the CRC diagnosis, but for the targeted therapies via the tumor-suppressing microRNA replacement. This review shows a general overview of the potential uses of the miRNAs in the CRC diagnosis, prognosis, and treatment with a special focus on the downregulated ones.

• Transactions of Materials Processing
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• v.24 no.4
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• pp.264-271
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• 2015

In the current study, a method was proposed to quantitatively predict the wear and fatigue life of a shearing die in order to determine an effective replacement period for the die. The shearing die model of a retainer manufacturing process was used for the proposed method of quantitative life prediction. The retainer is produced through shearing steps, such as piercing and notching. The shearing die of the retainer is carefully controlled because the dimensional accuracy of the retainer is critical. The fatigue life for the shearing die was predicted using ANSYS considering S-N curves of STD11 and Gerber’s equation. The wear life for the shearing die was predicted using DEFORM-3D considering the Archard’s wear model. Experimental shearing of the retainer was conducted to verify the effectiveness of the proposed method for predicting die life. The fatigue failure of the shearing die was macroscopically measured. The wear depth was measured using a 3D coordinate measuring machine. The results showed that the wear and fatigue life in the FE analysis agree well with the experimental results.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.1
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• pp.98-107
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• 2008

The purpose of this paper is to present an optimization scheme that aims at minimizing the expected cost per unittime. This study considers a linear connected-(r, s)-ouI-of-(m, n):f lattice system whose components are orderedlike the elements of a linear (m, n)-matrix. We assume that all components are in the state 1 (operating) or 0(failed) and identical and s-independent. The system fails whenever at least one connected (r, s)-submatrix offailed components occurs. To find the optimal threshold of maintenance intervention, we use a simulatedannealing(SA) algorithm for the cost optimization procedure. The expected cost per unit time is obtained byMonte Carlo simulation. We also has made sensitivity analysis to the different cost parameters. In this study,utility maintenance model is constructed so that minimize the expense under full equipment policy throughcomparison for the full equipment policy and preventive maintenance policy. The full equipment cycle and unitcost rate are acquired by simulated annealing algorithm. The SA algorithm is appeared to converge fast inmulti-component system that is suitable to optimization decision problem.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.501-503
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• 2000

Since an arrester has been generally used at the distribution line and abroad for the protection of electrical equipments against overvoltage (or abnormal surge) taking place in or from an electrical system, a fault, especially, in the distribution line is very likely to result in the destruction of insulation of other protection devices to cause an overall paralysis of a power system, a chaos. Considering the importance of arresters, its earlier replacement than its proposed life cycle causes an economical loss, and a negligence not to replace or repair it in time gives rise to a crucial accidence. The purpose of this paper is to invent an electric leakage current detector and to solve such problems by the continuous and regular inspection of an arrester.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1192-1197
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• 2000

Piping systems of the power generating stations have been generally protected by hydraulic and mechanical snubbers which can allow large displacements arising from temperature change while those can reduce or absorb stresses due to vibrations. However these snubbers require amounts of budget for maintenance or replacement because of the leakage, lubrication and finally short life cycle. Recently the snubbers consisted of wire rope have been proved to reduce vibrations of piping systems. While the wire rope snubbers are free of maintenance such as leakage and lubrication, imported price are so high. Now it is necessary to design, manufacture and certificate these wire rope snubbers.