• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.515-520
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• 2004

Manufacturing Production System (MPS) has been widely accepted in construction area for the productivity improvement. However, the MPS does not always provide cost and time saving. It often caused more delays and increased project cost. Therefore the use of the MPS technique, systematic decision-making process is needed by reviewing various project parameters such as cost and time. This study includes extensive literature reviews and case studies on MPS. As a result, a decision-making model is proposed. The decision-making flowchart and decision-making model are developed in three steps: (1) identification and categorization of decision-making factors; (2) calculations of benefits, cost, and duration in accordance with the location and the production capacity of the factory; (3) comparisons of MPS and on-site assembly by varying the locations and sizes of the factory

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.1
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• pp.115-123
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• 2021

Manufacturing execution system is a factory information system that handles production-related quality data as well as executes production plans of process unit for all resources in the production process on site. As the 4th industrial revolution, which maximizes an automation and connectivity with artificial intelligence, has become a hot topic, manufacturers are showing interest in building a smart factories, but enormous construction costs and unstandardized production processes are obstacles to smart factory construction. Therefore, this paper designs and implements a manufacturing execution system for building a smart factory in a deterioration factory. we propose a Web-based manufacturing execution system aiming at a smart factory at the basic level for steel wire processing. The proposed system will smoothly support interworking with the existing ERP system using REST APIs, and will consider extensibility so that it can be used in various devices and browsers. We will show practicality by implementing the proposed WoT-based manufacturing execution system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.1
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• pp.45-50
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• 2021

Machines and facilities are physically or chemically degenerated by continuous usage. The representative type of the degeneration is the wearing of tools, which results in the process mean shift. According to the increasing wear level, non-conforming products cost and quality loss cost are increasing simultaneously. Therefore, a preventive maintenance is necessary at some point. The problem of determining the maintenance period (or wear limit) which minimizes the total cost is called the 'process mean shift problem'. The total cost includes three items: maintenance cost (or adjustment cost), non-conforming cost due to the non-conforming products, and quality loss cost due to the difference between the process target value and the product characteristic value among the conforming products. In this study, we set the production volume as a decreasing function rather than a constant. Also we treat the process variance as a function to the increasing wear rather than a constant. To the quality loss function, we adopted the Cpm+, which is the left and right asymmetric process capability index based on the process target value. These can more reflect the production site. In this study, we presented a more extensive maintenance model compared to previous studies, by integrating the items mentioned above. The objective equation of this model is the total cost per unit wear. The determining variables are the wear limit and the initial process setting position that minimize the objective equation.

• Korean Journal of Construction Engineering and Management
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• v.23 no.6
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• pp.21-29
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• 2022

Productivity estimation of construction operations is crucial to successful project delivery. Especially in the preconstruction phase, the adequacy and effectiveness of plans directly affect the actual performance of operations. Currently, productivity estimation is conducted by referring to existing references such as the Construction Standard Production Rate. However, it is difficult to promptly apply changing conditions of operations when using such references. Moreover, it is difficult to deduce the optimal combination of construction machinery for the given condition. This paper presents a simple simulation model that can be used to generate productivity data that considers site conditions and construction equipment combination. The suggested method is expected to be used as a decision making assisting tool for practitioners who rely on estimations using the Construction Standard Production Rate when establishing construction plans using heavy machinery such as backhoes, loaders and dumptrucks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.26-35
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• 2020

Tunnel construction is an important part of Korean public construction projects. Although the development of various equipment and technologies has led to advances in tunnel construction methods that are implemented on sites, the cost standards related to such works do not yet reflect the realities of the construction sites. A literature review and site surveys were conducted to suggest reasonable cost standards for tunnel work that reflects the realities of the field. First, each item in the cost standards for tunnel work, as established in the Construction Standard Production Rates, were analyzed. The results were compared with the actual costs implemented on tunnel projects. The key items analyzed included those regarding the work cycle time, such as rock classification, profiling survey, drilling speed, and muck-disposal processing equipment combination, as well as the number of people put to tunneling work. Based on the site survey results, improved estimates regarding the cycle time per one tunnel drilling blast, drilling speed of the machine, muck disposal processing equipment combination, and the number of people put to tunneling work were suggested. This study suggests the cost standards that reflect the realities of tunneling sites. The results are expected to help ensure adequate costs for tunnel construction projects.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.3
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• pp.230-238
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• 2003

An effect on the enhancing production of hollow 'jumbo' structures and the condition of artificial reefs (dice and hollow jumbo structure) by side scan sonar were described. The experiment of the capture of fish in the jumbo structures and control site (non-artificial site) by trammel net and traps was done twice every year from 1998 to 2000. The relative catches by trammel net between in the jumbo structure and in the control site was significantly different in number and in weight at 5% level and also that by traps significantly different in weight. The t-test of the catch of finespotted flounder showed that the hollow jumbo structure was regarded as a breeding field because the average size of the flounder in the jumbo site was smaller than that in the control site. The search on the condition of the artificial reefs (dice and hollow jumbo structure) was performed by side scanning sonar which showed various phase of it such as accumulated, dispersed, scouring and partly buried. The result implied that in the area of sand bottom with strong tide like the western sea of Korea, the current criterion for constructing artificial reef should be modified because of the sand moving on the bottom.

• Biomolecules & Therapeutics
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• v.28 no.6
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• pp.549-560
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• 2020

Although DNA damage responses (DDRs) are reported to be involved in nitric oxide (NO) production in response to genotoxic stresses, the precise mechanism of DDR-mediated NO production has not been fully understood. Using a genotoxic agent aphidicolin, we investigated how DDRs regulate NO production in bovine aortic endothelial cells. Prolonged (over 24 h) treatment with aphidicolin increased NO production and endothelial NO synthase (eNOS) protein expression, which was accompanied by increased eNOS dimer/monomer ratio, tetrahydrobiopterin levels, and eNOS mRNA expression. A promoter assay using 5'-serially deleted eNOS promoters revealed that Tax-responsive element site, located at -962 to -873 of the eNOS promoter, was responsible for aphidicolin-stimulated eNOS gene expression. Aphidicolin increased CREB activity and ectopic expression of dominant-negative inhibitor of CREB, A-CREB, repressed the stimulatory effects of aphidicolin on eNOS gene expression and its promoter activity. Co-treatment with LY294002 decreased the aphidicolin-stimulated increase in p-CREB-Ser¹³³ level, eNOS expression, and NO production. Furthermore, ectopic expression of dominant-negative Akt construct attenuated aphidicolin-stimulated NO production. Aphidicolin increased p-ATM-Ser¹⁹⁸¹ and the knockdown of ATM using siRNA attenuated all stimulatory effects of aphidicolin on p-Akt-Ser⁴⁷³, p-CREB-Ser¹³³, eNOS expression, and NO production. Additionally, these stimulatory effects of aphidicolin were similarly observed in human umbilical vein endothelial cells. Lastly, aphidicolin increased acetylcholine-induced vessel relaxation in rat aortas, which was accompanied by increased p-ATM-Ser¹⁹⁸¹, p-Akt-Ser⁴⁷³, p-CREB-Ser¹³³, and eNOS expression. In conclusion, our results demonstrate that in response to aphidicolin, activation of ATM/Akt/CREB/eNOS signaling cascade mediates increase of NO production and vessel relaxation in endothelial cells and rat aortas.

• Clean Technology
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• v.23 no.1
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• pp.95-103
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• 2017

In this study, $ATiO_3$ (A = Ca, Sr, Ba) perovskite, which is the widely known for non $TiO_2$ photocatalysts, were synthesized using sol-gel method. And Ni was added at the A site of $ATiO_3$ by using that it is easy to incorporate. The physicochemical characteristics of the obtained $ATiO_3$ and Ni-$ATiO_3$ particles were confirmed using the X-ray diffraction (XRD) UV-visible spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), the $N_2$ adsorption-desorption isotherm measurement, and X-ray photoelectron spectroscopy (XPS). The $H_2$ was produced using the photolysis of MeOH. Using the Ni-$ATiO_3$ photocatalysts, $H_2$ production was higher than using the $ATiO_3$ photocatalysts. Especially, $273.84mmolg^{-1}$ $H_2$ was produced after 24 h reaction over the Ni-$SrTiO_3$. Also in the water (0.1 M KOH) with the Ni-$SrTiO_3$, $H_2$ production was $961.51mmolg^{-1}$ after 24 h reaction.

• Journal of Advanced Navigation Technology
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• v.20 no.5
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• pp.496-502
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• 2016

In this paper, we proposed and implemented a GUI-based system to recognize and record measured values of digital instruments in the industrial site through image processing. Unlike the existing vehicle license plate recognition system, the measured values of the measuring instrument are displayed on the LCD screen as digital numbers. So, the proposed system considers the decimal point, a negative sign, light reflected by LCD protective glass, and various disturbance factors. We used blob-labeling technique to recognize the numbers displayed on the LCD screen, the recognized number images were determined as certain numbers through the template matching, and recognized values were recorded in the storage device with measurement time. Therefore, the proposed system in this paper would reduce the burden of writing when recording the measured values of the inside/outside diameter or height of the product in the industrial site, so effective and errorless process management in production process is possible by preventing errors in recording measurements when written by hand.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.541-544
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• 2001

PC Box Girder was constructed by PSM(Precast Span Method) to solve the shortage of the construction period. The site case study was used in the PSM to find the construction productivity improvement. In this case study, main reasons of low productivity were founded unskilled technical engineers and insufficient equipment management winter season concrete curing condition. Productivity improvements are presented by assigning production personnel appropriately, motivation which increased by providing incentives for technical engineers, strictly cooperation of each participant, organizational teamwork, and Promoting productive work condition. Additional method of productivity improvements are continuous improvement of the work methods by considering the feedback on previous work, and continuous training to best handle the site conditions. This study of productivity improvement will help to use the most advantage of the PSM method and desire to successfully plan the future construction performance.