• Journal of the Korean institute of surface engineering
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• v.25 no.3
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• pp.117-125
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• 1992

In the electrolysis process of zinc plating impurity ions must be removed from zinc chloride plating solution because it's harmful to the current efficiency and the purity of zinc plating. In this study using zinc ball as a prcipitant instead of zinc dust, the fundamental data for continuous cementation process was studied. Based upon two series of experiments that consist of batch experiment with cylindrical zinc specimen and continuous experiment with zinc balls, following results have been obtained. In the continuous experiment all impurity ions have been removed within 1 hour regardless of various experimental conditions.

• Transactions of Materials Processing
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• v.27 no.2
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• pp.100-106
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• 2018

In the continuous casting process, the incidence of transverse surface cracks on the piece may occur by multiple and diverse variables. It is noted that mathematical models may predict only the occurance of the transverse surface cracks, but can require a lot of time (more than three days) to produce a result with this process. This study applied neural networks to predict whether the cracks on the piece surface occurs or does not occur. The computation time was shortened to three minutes, making it applicable to an on-line program, which predicts the non-cracks or cracks of the piece surface in the actual continuous casting process. In addition, the operating conditions to prevent the occurrence of the transverse surface cracks, using decision boundaries were also suggested.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.5
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• pp.27-37
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• 2020

Structural optimization problems with discrete design variables require more function calculations (or finite element analyses) than those in the continuous design space. In this study, a method to find an optimal solution in the discrete design of the truss structure is presented, reducing the number of function calculations. Because a continuous optimal solution is the Karush-Kuhn-Tucker point that satisfies the optimality condition, it is assumed that the discrete optimal solution is around the continuous optimum. Then, response values such as weight, displacement, and stress are predicted using approximate models-referred to as hybrid metamodels-within specified design ranges. The discrete design method using the hybrid metamodels is used as a post-process of the continuous optimization process. Standard truss design problems of 10-bar, 25-bar, 15-bar, and 52-bar are solved to show the usefulness of this method. The results are compared with those of existing methods.

• Phonetics and Speech Sciences
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• v.2 no.2
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• pp.17-25
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• 2010

This study explores whether Koreans exploit their native coda-neutralization process when recognizing words in Korean continuous speech. According to the phonological rules in Korean, coda-neutralization process must come before the liaison process, as long as the latter(i.e. liaison process) occurs between 'words', which results in liaison-consonants being coda-neutralized ones such as /b/, /d/, or /g/, rather than non-neutralized ones like /p/, /t/, /k/, /ʧ/, /ʤ/, or /s/. Consequently, if Korean listeners use their native coda-neutralization rules when processing speech input, word recognition will be hampered when non-neutralized consonants precede vowel-initial targets. Word-spotting and word-monitoring tasks were conducted in Experiment 1 and 2, respectively. In both experiments, listeners recognized words faster and more accurately when vowel-initial target words were preceded by coda-neutralized consonants than when preceded by coda non-neutralized ones. The results show that Korean listeners exploit the coda-neutralization process when processing their native spoken language.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.474-478
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• 1986

The phenomenon of a continuous Steel-making process was studied with a set of collected equilibrium data for the steel-oxidation reactions. Mass and Heat balances were also established. Mass transfer constants which are physically unmeasurable but escential for the simulation study in the steel-making process were calculated from the experimental data using an optimization technique. Based on these data various operating conditions and process characteristics were examined.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.329-332
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• 2006

$Conform^{TM}$, a continuous extrusion forming process can produce a variety of very long extruded products such as aluminum alloyed wires, strips and profiles, hollow sectioned tubes, coated wires used in the current forming industry. This process has some advantages like as superiority of pre-heating free, availability of high extrusion ratio and continuous forming without stroke limit. But it is still difficult to analyze the realistic model of the process. In this study the analysis using two-dimensional model of $Conform^{TM}$ process together with several parametric investigations on the heat transfer are carried out by FEA code DEFORM $^{TM}2D$. In spite of simple model the results of analysis shows a good guidance to design the real process.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.31-38
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• 2013

The degradation of 4-chlorophenol(4-CP) by various AOPs(Advanced Oxidation Processes) with continuous feeding of $H_2O_2$, including the ultraviolet/hydrogen peroxide, the Fenton and the photo-Fenton process has been investigated. The photo-Fenton process showed the highest removal efficiency for degradation of 4-chlorophenol than those of other AOPs including the Fenton process and the combined UV process with continuous feeding of $H_2O_2$. In the photo-Fenton process, the optimal experimental condition for 4-CP degradation was obtained at pH 3. Also the 4-CP removal efficiency increased with decreasing of the initial 4-CP concentration. 4-chlorocatechol and 4-chlororesorcinol were identified as photo-Fenton reaction intermediates, and the degradation pathways of 4-CP in the aqueous phase during the photo-Fenton reaction were proposed.

• Transactions of Materials Processing
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• v.14 no.6 s.78
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• pp.547-552
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• 2005

In general, the sheet metal and die are described by finite elements for the simulation of the metal forming processes. Because the characteristics as continuum of the sheet metal are represented with triangles and rectangles, the errors occur inevitably in finite element analysis. Many contact schemes to describe the deformation modes exactly have been introduced in order to decrease these errors. In this study, a scheme for continuous contact treatment is proposed in order to consider the realistic behavior of contact phenomena during the forming process. The discrete mesh causes stepwise propagation of contact nodes of the sheet even though the contact region of the real forming process is altered very smoothly. It gives rise to convergence problem in case that the process, for example bending process, is sensitive to the contact between the sheet and the tools. The analysis of the unconstrained cylindrical bending process without blank holder is also presented in order to investigate the effect of the proposed algorithm.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1065-1069
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• 2005

The construction failures can be decreased through continuous improvement of construction process based upon the information of construction failures. Herein, the information of construction failures can be utilized as the key factor for identifying and enhancing various ineffective construction processes that can prevent failures. This research proposes a process model for the continuous improvement of construction processes by using construction failure information. Extensive reviews and analyses of literatures related to construction failures are performed to investigate its definition, type, cause, and lessons learned. This research adapts process modeling methodology and case-based reasoning for the development of the proposed CIMCP(continuous improvement model of construction process), and then suggests its framework that contains modules of case retrieval, case index, and case adaptation.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.105-108
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• 2006

It has been issued to fabricate nano-scale patterns with large-scale in the field of digital display. Also, large-scale fabrication technology of nano pattern is very important not only for the field of digital display but also for the most of applications of the nano-scale patterns in the view of the productivity. Among the fabrication technologies, UV nano imprinting process is suitable for replicating polymeric nano-scale patterns. However, in case of conventional UV nano imprinting process using flat mold, it is not easy to replicate large areal nano patterns. Because there are several problems such as releasing, uniformity of the replica, mold fabrication and so on. In this study, to overcome the limitation of the conventional UV nano imprinting process, we proposed a continuous UV nano imprinting process using a pattern roll stamper. A pattern roll stamper that has nano-scale patterns was fabricated by attaching thin metal stamper to a roll base. A continuous UV nano imprinting system was designed and constructed. As practical examples of the process, various nano patterns with pattern size of 500, 150 and 50nm were fabricated. Finally, geometrical properties of imprinted nano patterns were measured and analyzed.