• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.615-626
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• 2019

In this study, the applicability of PHC pile jointing method using rectangular steel tubular was studied. PHC pile joints are welded and bolt assembly. The bolt assembly method is a method that improves the various problems of welded joints. Numerical analysis and tests were conducted to analyze the applicability of the PHC pile jointing method using a rectangular steel tubular. The tests were carried out to test the material properties of the rectangular steel tubular material and the bending test of the pile joints. The numerical analysis was interpreted in the same conditons as the tests conditions. As a result, the material strength of each rectangular steel tubular could be used as a joint material. In the bending test, it was evaluated as a sTable material above the allowable stress of piles. In the numerical analysis results under the same conditions as the tests, it was possible to apply the pile joint material without exceeding the allowable stress of the material.

• Special Issue of the Society of Naval Architects of Korea
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• 2007.09a
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• pp.118-127
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• 2007

SAW(Submerged Arc Welding) process is generally applied to a wide range of welding area in the fabrication of steel structure. This process has a good characteristic properties such as the high quality of welds and the high deposition rates, but in case of welding on a thick steel plate, it also has higher cold crack susceptibility than that of a thin steel plate. The purpose of this research is to find the main factor of crack generation and clarify the countermeasure for crack prevention, and then establish the optimum welding condition in a heavy thick steel plate. The results of this study are as follows, 1. The cause of crack generation is found the diffusible hydrogen penetrated into weld metal by decomposition of the remained moisture in SAW flux during welding. 2. For the removal of diffusible hydrogen, the raw materials of SAW flux are to be dehydrated at the high temperature in the initial manufacturing stage. 3. Mechanical properties of weld metal welded with the dehydrated SAW flux were evaluated very excellent, furthermore the weld metal has been proved to have low diffusible hydrogen content with 3.1ml /100g. 4. The weldability and quality welded with thick steel plates were improved by establishing the new optimum welding condition.

• Journal of Practical Engineering Education
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• v.12 no.1
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• pp.203-212
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• 2020

This study surveyed 244 employees out of a total of 356 graduates from the steel industry in 2015 to February 2019. The employment rate of graduates is POSCO 67.7%, Hyundai Steel 23.8%, POSCO families 13.1%, and Hyundai Steel families 8.5%. The national certificates acquired by each section were surveyed, with 53.1% of metal section, 39.8% of mechanical section, and 7.1% of other section. Preferred national certificates were POSCO, machinery maintenance industry technicians, steelmaking technicians, and Hyundai Steel followed steelmaking technicians, mechanical maintenance industrial technicians. Among other certifications, the national certificate of industrial safety industrial engineer was preferred. In addition, the average number of national certificates per person for major employment is 5.06 for POSCO, 5.35 for POSCO families, 5.29 for Hyundai Steel, and 4.73 for Hyundai Steel families. The average number of national certificates for S-OIL, KEPCO, Poongsan Metal, etc., is 2.51. In conclusion, it was found that the national certificates related to majors are used as the main evaluation data in finding suitable majors and competency for the job when recruiting talents.

• Journal of the Korean Society of Industry Convergence
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• v.5 no.3
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• pp.173-178
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• 2002

In this research, we have worked about the radiation thermometer which can be applied to the hazard circumstance such as steel plant. In the results, we have developed radiation thermometer of a measuring range $500-1500^{\circ}C$, accuracy ${\pm}0.1%$, repeatability ${\pm}0.1%$, resolution $0.2^{\circ}C$. We performed extensive field test for 6 months at the hot strip mill in steel plant. Through the test, we have confirmed the reliability of the developed pyrometer.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.71-73
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• 2003

The paper discussed for energy saving technology of electric arc furnace (EAF) in steel making industry. The energy of EAF in steel making process is nearly 10% of total manufacturing cost. This paper is shown new trand of energy saving technology and future study analysis of technological evolution of the EAF by 2010 issued IISI.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.10a
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• pp.10-26
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• 2005

In our model, we keep inventory to satisfy uncertain demands which arrives irregularly. In this situation, we have additional two constraints. First, we need to have certain amount of order consolidation (consolidation constraint) for the orders to replenish the inventory because of production or purchase constraint. And also, if we order at a certain date which was set by administrative convenience, we have amount constraint to order the consolidated order demands (capacity constraint). We showed this variant inventory policy is needed in steel industry and note that there will be possible similar case in industry. To deal with this case, we invented a variant replenishment policy and show this policy is superior to other possible polices in the consolidation constraint case by extensive simulation. And we derive a combined solution method for dealing with the capacity constraints in addition to the consolidation constraints. For this, we suggest a combined solution method of integer programming and simulation.

• Journal of the Korea Safety Management & Science
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• v.18 no.2
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• pp.109-118
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• 2016

IPS(Ideal Production System) is a strategic cost management establishing ideal target cost, innovating cost structure and reduction. However, IPS was commonly used in assembly industry acquiring components and using them to assemble vehicles etc. Applying IPS to steel industry is a new try and not easy because cost elements in flow manufacturing are clustered and obfuscated in a complicated way. This paper proposes ICM (Ideal Cost Management) method adaptive to steel industry. One of the biggest advantages is that ICM could classify and categorize costs in detail according to accounts and manufacturing machines. Based on ICM information, steps of extracting and maximizing ideas are followed effectively. From 2013, ICM was applied successfully to POSCO Pohang Steel Works 38 factories.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.2
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• pp.99-112
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• 2006

In our model, we keep inventory to satisfy uncertain demands which arrives irregularly. In this situation, we have additional two constraints. First, we need to have certain amount of order consolidation (consolidation constraint) for the orders to replenish the inventory because of production or purchase amount constraint. And also, if we order at a certain date which was set by administrative convenience, we have capacity constraint to order the consolidated order demands (capacity constraint). We show this variant inventory policy is needed in steel industry and note that there will be possible similar case in industry. To deal with this case, we invent a variant replenishment policy and show this policy is superior to other possible polices in the consolidation constraint case by extensive simulation. And we derive a combined solution method for dealing with the capacity constraints in addition to the consolidation constraints. For this, we suggest a combined solution method of integer programming and simulation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.193-195
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• 2011

Nowadays, climatic environment change has become a major issue in the world. This causes major emissions of carbon dioxide industries steel industry, thermal power industry, cement industry is essential in the reduction of carbon dioxide, which is based on total carbon dioxide emissions account for most of the construction industry in an effort to minimize the environmental load is needed. accordingly, through case studies, It can be induce the selection to minimize environmental load by comparing the output of quantitative energy consumption and carbon dioxide emissions per constructional methods. As a result of this study, RC Structure was less environmental load than SC structure.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.357-358
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• 2012