• Nuclear Engineering and Technology
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• v.52 no.3
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• pp.647-653
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• 2020

Stainless steel is used commonly in nuclear applications for shielding radiation, so in this study, three different types of new stainless steel samples were designed and developed. New stainless steel compound ratios were determined by using Monte Carlo Simulation program Geant 4 code. In the sample production, iron (Fe), nickel (Ni), chromium (Cr), silicium (Si), sulphur (S), carbon (C), molybdenum (Mo), manganese (Mn), wolfram (W), rhenium (Re), titanium (Ti) and vanadium (V), powder materials were used with powder metallurgy method. Total macroscopic cross sections, mean free path and transmission number were calculated for the fast neutron radiation shielding by using (Geant 4) code. In addition to neutron shielding, the gamma absorption parameters such as mass attenuation coefficients (MACs) and half value layer (HVL) were calculated using Win-XCOM software. Sulfuric acid abrasion and compressive strength tests were carried out and all samples showed good resistance to acid wear and pressure force. The neutron equivalent dose was measured using an average 4.5 MeV energy fast neutron source. Results were compared to 316LN type stainless steel, which commonly used in shielding radiation. New stainless steel samples were found to absorb neutron better than 316LN stainless steel at both low and high temperatures.

• Journal of the Korea Safety Management & Science
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• v.13 no.4
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• pp.213-223
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• 2011

Recent cross-country competition and Chinese steel industry because of the emerging steel industry in Korea is a very difficult situation. Therefore, the steel industry in order to overcome this difficult market environment, the quality, cost competitiveness, enhance customer service levels and enhance international competitiveness through is needed. In this study, the purpose of strengthening the competitiveness of steel companies in order and hit the recovery of raw materials have been developed to optimize the model, developed before and after the results were analyzed. In addition, when applied to other products in order to minimize risk and optimize cutting trial stage of development details of the model is presented in detail. Therefore, the developed model was applied to order the recovery of raw materials hits and significantly improved production planning time has been shortened dramatically. In the present study the contents of other products when properly applied and the competitiveness of companies to improve customer service levels are expected to be helpful.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.3
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• pp.279-286
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• 2015

To achieve lightweight design, research & development of various lightweighting technologies such as hydroforming are underway worldwide. In the case of hydroforming, application of ultra high strength steel is essential for weight reduction of the car. However, considering common high-strength carbon steel, it is not suitable to the actual hydroformed parts since the lack of formability. DP steel offers an outstanding combination of strength and formability as a result of their microstructure. DP steel has high strength and good formability but it's difficult to secure stable quality of welding section because of softening of weld section and chemical composition. Therefore, most of companies use LASER welding when making high strength tube. Electric resistance welding is excellent production method for steel tube manufacturing considering the productivity. Optimum electric resistance welding technology is needed to be developed for application of high strength hydroformed parts using DP steel. This study is comprehensive research & development from electric resistance welding to actual formabililty evaluation.

• Design & Manufacturing
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• v.15 no.3
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• pp.13-18
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• 2021

In plate forming technology, cylindrical drawing process is widely used in industry due to technological development. In this study, we used stainless steel 3042B and stainless steel 304J1, which are the most commonly used materials in the production of cold and hot water tanks for water purifiers, among cylindrical drawing products. Under the same conditions, the thickness of the sidewall of the product formed by drawn experiment was studied. As a result of the experiment, the bottom thickness of stainless steel 304J1 was considered to be thick. It is judged that the defect rate can be reduced by changing the breaking phenomenon of the floor surface of the cold and hot water bottles to the material of stainless steel 304j1. Stainless steel 304 2B material shows a sharp change in thickness from punch corner R to sidewall position, while stainless steel 304J1 material showed a uniform change from punch corner R to sidewall position. Stainless steel 304J1 material is considered to improve the clamping of the product in the process of extracting the product after hand drawing. The appearance of stainless steel 3042B products is considered to produce more wrinkles in the flange, which exerts greater tensile force on the sidewall during molding, resulting in uneven sidewall thickness.

• Advances in concrete construction
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• v.12 no.6
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• pp.499-505
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• 2021

Geopolymer binders fascinate the attention of researchers as a replacement to cement binder in conventional concrete. One-ton production of cement releases one ton of carbon-dioxide in the atmosphere. In the replacement of cement by geopolymer material, there are two advantages: one is the reduction of CO₂ in the atmosphere, second is the utilization of Fly ash and Ground granulated blast furnace slag (GGBFS) are by-products from coal and steel industries. This paper focuses on the mechanical properties of steel fiber reinforced geopolymer concrete. The framework considered in this research work is geopolymer source (Fly ash, GGBFS and crimped steel fibre) and alkaline activator which consists of NaOH and Na₂SiO₃ of molarity 8M. Here the Na₂SiO₃ / NaOH ratio was taken as 2.5. The variables considered in this experimental work include Binder content (360,420 and 450 kg/m³), the proportion of Fly ash and GGBS (70-30, 60-40 and 50-50) for three different grades of Geopolymer concrete (GPC) GPC 20, GPC 40 and GPC 60. The percentage of crimped steel fibres was varied as 0.1%, 0.2%, 0.3%, 0.4% and 0.5%. Generally, the inclusion of steel fibres increases the flexural and split tensile strength of Geopolymer concrete. The optimum dosage of steel fibres was found to be 0.4% (by volume fraction).

• Korea Trade Review
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• v.47 no.2
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• pp.133-154
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• 2022

The Baltic Capesize Index (BCI), which is used as an indicator for marine transportation of steel raw materials, is one of the key economic indexes for managing the risk of loss due to rapid market fluctuations when steel companies establish business strategies and procuring plans for raw materials. Still, the conditions of supply and demand of steel raw materials has been extremely affected by volatility shocks from drastic events like the financial crisis such as the Lehman Brothers incident and changes in the external environment such as COVID-19. And, especially since the 2008 financial crisis, endeavors to predict the market conditions of the steel raw material is becoming more and more arduous for the deepening uncertainty and increased volatility of BCI, which has been used as a leading indicator of the real economy. This study investigates the correlation between the steel raw material market and the marine transportation market by estimating the spillover effect of information between markets. The vector error correction model (VECM) was used to analyze information transfer based on the correlation between the BCI and crude steel production, capesize fleet supply, raw material price, and cargo volume.

• 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.

• Ocean and Polar Research
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• v.38 no.3
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• pp.225-234
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• 2016

This project sought to conduct an economic feasibility study regarding the commercial production of bio-hydrogen by the marine hyperthermophilic archaeon, Thermococcus onnurineus NA1 using carbon monoxide-containing industrial off-gas. We carried out the economic evaluation of the bio-hydrogen production process using the raw material of steel mill by-product gas. The process parameter was as follows: $H_2$ production rate was 5.6 L/L/h; the conversion of carbon monoxide was 60.7%. This project established an evaluation criterion for about 10,000 tonne/year. Inflation factors were considered as 3%. The operating costs were recalculated based on prices in 2014. The total investment required for development was covered 30% by capital and 70% by a loan. The operation cost for the 0.5-year test and integration, and the cost for the first three months in the 50% production period were considered as the working capital in the cost estimation. The costs required for the rental of office space, facilities, and other related costs from the construction through to full-scale production periods were considered as continuing expenses. Materials, energy, waste disposal and other charges were considered as the operating cost of the development system. Depreciation, tax, maintenance and repair, insurance, labor, interest rate charges, general and administrative costs, lubrication and miscellaneous expenses were also calculated. The hydrogen price was set at US$ 4.15/kg for the economic evaluation. As a result, the process was considered to be economical with the payback period of 6.3 years, NPV of 18 billion Won and IRR of 26.7%.

• Korean System Dynamics Review
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• v.8 no.2
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• pp.115-140
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• 2007

Changes in material use, energy use and emissions profiles of steel industry are the result of complex interrelationships among a multitude of technological and economic drivers. To better understand and guide such changes requires that attention is paid to the time-varying consequences that technology and economic influences have on an industry's choice of inputs and its associated outputs. We briefly review the range of policy issues in our paper and assess the impact that climate-change policies may have on energy use and carbon emissions in Korea steel industry. We then present the models of Korea steel industry's energy and product flow regarding environmental regulations by using system dynamics simulation methodology(SD). Time series data and engineering information are combined to endogenously specify changes in technologies, fuel mix, and production processes within dynamic simulation model. Through a various scenario, ramifications that the convention of climate change would to steel industry is analyzed, and based on the study results, strategies against environment changes is contemplated in various perspectives to contribute to minimize the risks concerning the uncertain future and to be conducive to Korea steel industry's sustainable development.

• Corrosion Science and Technology
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• v.12 no.6
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• pp.288-294
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• 2013

When the automotive body enters an electrocoating tank while applying an electric current, its steel surface is exposed to a very low induced current. Consequently, surface defects of coating may arise if the steel surface has lack of electric uniformity due to local defects such as local oxide. In this study, we investigated the preceding assessment methods to evaluate steel susceptibility of the low induced current during electrocoating before mass production. Prior to general electrocoating, we applied low constant voltage such as 3V or low constant current densities such as $0.35mA/cm^2$ and $0.50mA/cm^2$. In result, we confirmed that such methods were efficient for assessing steel susceptibility of low induce current during electrocoating.