• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.4
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• pp.85-90
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• 2012

Wet pressing process has great influence not only on the paper properties but also on the efficiency of total manufacturing process including energy efficiency. The slow drainage propensity of old corrugated container(OCC) might require more complicated control of wet pressing process. In this study, the change in press efficiency and in structure of wet sheet by the various condition of laboratory roll press simulator were evaluated to provide background information about wet pressing of OCC. The higher pressure and the slower machine speed resulted in higher efficiency of wet pressing but the change trends of dryness depending on the wet press pressure and machine speed were shown differently according to OCC treatment. The effects of water contents of felt on the wet press efficiency and sheet structure were also investigated. The higher contents of water in felt resulted in less removal of water generally and the crushed structure of wet sheet were appeared especially at higher pressure.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.3
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• pp.91-96
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• 2023

To verify the quality of bubbles during the use of quartz glass crucibles (QC), an appropriate accelerated testing method was proposed. The bubble state of discarded waste crucibles obtained from actual Czochralski (Cz) processes was analyzed, and optimal heat treatment conditions were suggested by varying temperature, pressure, and time using the QC test piece. By subjecting the samples to heat treatment at 1450℃, 0.4 Torr, and 40 hours, it was possible to control the bubble size and density to a similar level as those generated in the actual Cz process. In particular, by selecting a relatively lower pressure of 0.4 Torr compared to the typical range of 10~20 Torr applied in the Cz process, the time required for accelerated bubble formation testing could be reduced. However, it was determined that increasing the heat treatment temperature to 1550℃ led to the phenomenon of Ostwald ripening, resulting in larger bubbles and a rapid decrease in density. Therefore, it was concluded that it was not a suitable condition for the desired b ake test.

• Composites Research
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• v.36 no.2
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• pp.108-116
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• 2023

In this paper, kinematic design and multi-body dynamics analysis were conducted to develop a small manipulator platform for automating the maintenance of structures made of composite materials. To design manipulator kinematically, the existing composite repair process was considered. The 3D design was conducted after selecting the basic specifications of manipulator and end-effecter in consideration of the patch lamination process for repair. Then, variables necessary for simulation and control were generated in MATLAB through inverse kinematic analysis. To evaluate the structural stability of platform, multibody dynamics analysis was conducted using Altair Inspire and Optistruct. Based on the simulation conducted in Inspire, multibody dynamics analysis was conducted in Optistruct, and structural stability was verified through the results of maximum displacement and Von-Mises stress over time. To verify the design, manufacturing and controlling of platform were conducted and compared with the simulation. It was confirmed that the actual repair process path and the simulation showed a good agreement.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.5
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• pp.316-325
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• 2012

In this study, we suggested adequate control technology by analyzing emission process and main chemical of VOC/HAPs generated from four paint factories in Busan area. And we estimated whether Kapok fiber, which is a natural material, can be commercially used for an absorbent by testing adsorption ability. As a result of this sturdy, above 60% of VOC/HAPs was volatilized and dispersed inside the working place without conducting control system of facilities during manufacturing paints. Concentration profile of VOC/HAPs, which is volatile naturally outside the factories, is surveyed above 70% at Toluene, Ethylbenzene, and Xylene. And a result of evaluation of odor attribution level about the component whose Odor Threshold is known, it is estimated that major cause material of A, B, C factories is Toluene and that of D factory is m/p-Xylene. And that result presented design arguments such as facilities specifications, activated carbon filling volume, and replace cycle of activated carbon as control technology. Also, that result presented emission process improvement such as adsorption of central-controlled ventilation device, installation of inlet flenge, and potable cleaning process. The rate of pollutant adsorption of Kapok fiber, which is natural material, is indicated about 91.9%, 66.7%. That result validated the possibility as replacement of activated carbon.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.12
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• pp.1249-1255
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• 2011

In modern large-scale semiconductor manufacturing clean rooms, the energy consumed by the outdoor air-conditioning system during heating, humidification, cooling, and dehumidification of the incoming outdoor air represents about 45% of the total air-conditioning load required to maintain a clean-room environment. In particular, the energy required for humidification of the outdoor air in winter is very high. Therefore, evaluation and comparison of the energy consumption in key humidification systems, viz., steam-humidification and water-spray-humidification systems, used in outdoor air-conditioning systems would be useful to reduce the outdoor air-conditioning load in clean rooms. In the present study, an experiment with an outdoor air flow of 1000 $m^3$/h was conducted to compare the air-conditioning process and energy consumption in outdoor air-conditioning systems with electrodeboiler steam humidifiers and air-washer water spray humidification systems. The experimental results showed that the water-spray-humidification-type outdoor air-conditioning system consumed less electrical power than did the steam-humidification-type system and was more energy efficient during winter.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.390-398
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• 2020

To solve the problem of frequent component failure in guided weapons, a process of component failure in developed countries was investigated and analyzed. The suitability of component control, including risk assessment, analysis of operational impact, and the establishment of response measures, was also demonstrated. In addition, the economic effects of component control were presented by estimating the costs incurred if component control is performed in advance, after-sales, and non-management. DMSMS problems refer to losses or impending losses of an item, raw material, or software manufacturer or supplier. A problem with the discontinuation of parts occurs when the manufacturer or supplier ceases to produce and support the necessary parts, materials, or software, or when the supply of raw materials is no longer possible. Hence, it is important to recognize that failure to all parts of the system can occur.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.237.1-237.1
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• 2014

Etching is one of the most important steps in semiconductor manufacturing. In etch process control a critical task is to stop the etch process when the layer to be etched has been removed. If the etch process is allowed to continue beyond this time, the material gets over-etched and the lower layer is partially removed. On the other hand if the etch process is stopped too early, part of the layer to be etched still remains, called under-etched. Endpoint detection (EPD) is used to detect the most accurate time to stop the etch process in order to avoid over or under etch. The goal of this research is to develop a hardware and software system for EPD. The hardware consists of an Optical Plasma Monitor (OPM) sensor which is used to continuously monitor the plasma optical emission intensity during the etch process. The OPM software was developed to acquire and analyze the data to perform EPD. Our EPD algorithm is based on the following theory. As the etch process starts the plasma generated in the vacuum is added with the by-products from the etch reactions on the layer being etched. As the endpoint reaches and the layer gets completely removed the plasma constituents change gradually changing the optical intensity of the plasma. Although the change in optical intensity is not apparent, the difference in the plasma constituents when the endpoint has reached leaves a unique signature in the data gathered. Though not detectable in time domain, this signature could be obscured in the frequency spectrum of the data. By filtering and analysis of the changes in the frequency spectrum before and after the endpoint we could extract this signature. In order to do that, first, the EPD algorithm converts the time series signal into frequency domain. Next the noise in the frequency spectrum is removed to look for the useful frequency constituents of the data. Once these useful frequencies have been selected, they are monitored continuously in time and using a sub-algorithm the endpoint is detected when significant changes are observed in those signals. The experiment consisted of three kinds of etch processes; ashing, SiO2 on Si etch and metal on Si etch to develop and evaluate the EPD system.

• Food Science of Animal Resources
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• v.35 no.4
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• pp.494-501
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• 2015

The aim of this study was to examine the effectiveness of pre-cooking conditions on the quality characteristics of ready-to-eat (RTE) Samgyetang. Raw chickens were steamed under the different conditions of 50℃/30 min (T1), 65℃/30 min (T2), 85℃/30 min (T3), and 90℃/10 min (T4) prior to retorting at 120℃ for 65 min. The results showed that pre-cooking conditions in all treated samples could reduce fat contents in breast and leg meats by 8.5-11.7％ and 10.0-11.0％ compared to the control, even though there were no significant differences among treatments (p>0.05). The L* and b* values of breast and leg meats treated with the higher temperature and longer time conditions were significantly higher than the control (p<0.05), while a* values tended to decrease despite of not to a significant extent (p>0.05). Moreover, apparent viscosity and water soluble protein showed insignificant differences (p>0.05) among the samples as a result of the retorting process, which might have more negative influences on the quality. T2 samples obtained significantly the highest average Quantitative Descriptive Analysis (QDA) score and transmittance value, representing the most clear broth among the samples, compared to the control. On the other hand, T3 showed the highest cooking loss among the treatments and the lowest QDA scores among the samples. In conclusion, pre-cooking treatment prior to retorting in manufacturing Samgyetang is a plausible way to reduce its fat content. A pre-cooking condition at either 65℃ for 30 min, or 90℃ for 10 min are recommended for producing Samgyetang with optimum quality.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.2
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• pp.87-93
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• 2018

This Study Propose A New Approach To Impliment A Intelligent Robot Control Based on Voice Recognition For Smart Factory Automation Since human usually communicate each other by voices, it is very convenient if voice is used to command humanoid robots or the other type robot system. A lot of researches has been performed about voice recognition systems for this purpose. Hidden Markov Model is a robust statistical methodology for efficient voice recognition in noise environments. It has being tested in a wide range of applications. A prediction approach traditionally applied for the text compression and coding, Prediction by Partial Matching which is a finite-context statistical modeling technique and can predict the next characters based on the context, has shown a great potential in developing novel solutions to several language modeling problems in speech recognition. It was illustrated the reliability of voice recognition by experiments for humanoid robot with 26 joints as the purpose of application to the manufacturing process.

• Journal of Food Hygiene and Safety
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• v.37 no.3
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• pp.181-188
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• 2022

Despite the recent increase in the consumption level of the processed meat-byproducts, the health and safety issue has consistently been raised in the processes of production, distribution and consumption. The purpose of this study is to analyze and evaluate the microbiological hazard elements in the Korean sausage, "Sundae," to present not only the safety standard of meat by-product vendors based on HACCP (Hazard Analysis Critical Control Point), but also the quality control criteria and sanitary arrangements of small manufacturers. For the study, the microbiological hazards in 24 raw materials, 7 manufacturing processes, 40 facilities and tools, 17 workplace environment, and 12 workers were analyzed. The analysis revealed the hazardous elements in the initial stages with 6.28 and 4.07 log CFU/g of total aerobic count and coliforms, respectively, detected from the porcine blood and 3.23 log CFU/g of coliforms from the porcine small intestines. The result also showed that the total aerobic counts and coliforms in the process of mixing and filling process exceeds the standards in the hygiene guidelines by Natick with the total aerobic counts of 5.23, 5.45 log CFU/g, and the coliforms of 3.25, and 3.31 log CFU/g, respectively. Although the detected total aerobic count and the coliforms in the filling and washing rooms exceeded the standards, it was found that the total aerobic count was significantly reduced by 98% after cleaning and disinfecting and no coliforms was detected in any process thereafter. In order to achieve high level of safety in the manufacturing processes of Sundae, the separation of washing and disinfection room from the other sections and the sanitation control of the workers must be preceded, along with strict monitoring in the storage and distribution processes. The study raises necessity for additional studies for the safety evaluation of the processed meat-byproducts and further researches on the validity of the critical limits.