• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.881-882
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• 2006

In 1997, Dr. James Chien-Min Sung patented the technology of making diamond tools according to a predetermined pattern. The optimization of this pattern may double the tool life and the cutting speed. In 1998, Sung also made $DiaGrid^{(R)}$ saw segments that showed superior performance in cutting granite and marble. In 2000, Sung visited Shinhan and introduced them this revolutionary concept of diamond saw segments. In 2005, Shinhan adapted the idea and produced saw segments with diamond grits set in a predetermined pattern, their results confirmed that the sawing speed and the sawing life were both improved over conventional designs.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.1
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• pp.21-28
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• 2008

The final polishing process is based on slurry, pad, conditioner, equipment. Therefore, the concept of wafer final polishing is also necessary for repeatability of results between polished wafers. In this study, the machining conditions have a pressure, table speed, machining time and slurry ratio. This research investigated the surface characteristics that apply variable machining conditions and response surface methodology was used to obtain more flexible and optimumal condition base on Taguchi method. On the base of estimated response surface curvature from the equation and results of Taguchi method, combined design of experiment was considered to lead to optimumal condition. Finally, polished wafer was obtained mirror like surface.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.1
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• pp.61-66
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• 2012

Chemical Mechanical Planarization (CMP) is a polishing process used in the microelectronic fabrication industries to achieve a globally planar wafer surface for the manufacturing of integrated circuits. Pad conditioning plays an important role in the CMP process to maintain a material removal rate (MRR) and its uniformity. For metal CMP process, highly acidic slurry containing strong oxidizer is being used. It would affect the conditioner surface which normally made of metal such as Nickel and its alloy. If conditioner surface is corroded, diamonds on the conditioner surface would be fallen out from the surface. Because of this phenomenon, not only life time of conditioners is decreased, but also more scratches are generated. To protect the conditioners from corrosion, thin organic film deposition on the metal surface is suggested without requiring current conditioner manufacturing process. To prepare the anti-corrosion film on metal conditioner surface, vapor SAM (self-assembled monolayer) and FC (Fluorocarbon) -CVD (SRN-504, Sorona, Korea) films were prepared on both nickel and nickel alloy surfaces. Vapor SAM method was used for SAM deposition using both Dodecanethiol (DT) and Perfluoroctyltrichloro silane (FOTS). FC films were prepared in different thickness of 10 nm, 50 nm and 100 nm on conditioner surfaces. Electrochemical analysis such as potentiodynamic polarization and impedance, and contact angle measurements were carried out to evaluate the coating characteristics. Impedance data was analyzed by an electrical equivalent circuit model. The observed contact angle is higher than 90o after thin film deposition, which confirms that the coatings deposited on the surfaces are densely packed. The results of potentiodynamic polarization and the impedance show that modified surfaces have better performance than bare metal surfaces which could be applied to increase the life time and reliability of conditioner during W CMP.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.50-53
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• 2003

CMP (chemical mechanical polishing) process remained to solve several problems in deep sub-micron integrated circuit manufacturing process. especially consumables (polishing pad, backing film, slurry, pad conditioner), one of the most important components in the CMP system is the slurry. Among the composition of slurries (buffer solution, bulk solution, abrasive particle, oxidizer, inhibitor, suspension, antifoaming agent, dispersion agent), the abrasive particles are important in determining polish rate and planarization ability of a CMP process. However, the cost of abrasives is still very high. So, in order to reduce the high COO (cost of ownership) and COC (cost of consumables) in this paper, we have collected the silica abrasive powders by filtering after subsequent CMP process for the purpose of abrasive particle recycling. And then, we have studied the possibility of recycle of reused silica abrasive through the analysis of particle size and hardness. Also, we annealed the collected abrasive powders to promote the mechanical strength of reduced abrasion force. Finally, we compared the CMP characteristics between self-developed KOH-based silica abrasive slurry and original slurry. As our experimental results, we obtained the comparable removal rate and good planarity with commercial products. Consequently, we can expect the saving of high cost slurry.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.10
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• pp.235-243
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• 2019

In South Korea, millions of poultry have died due to repeated heat waves every year. The purpose of this study is to analyze the characteristics of heating and cooling loads of chicken houses in Korea and to present an effective insulation and ventilation measures to minimize the damage of poultry due to summer heat wave and to save energy in chicken houses in winter. The heating and cooling loads of standard chicken house were calculated. As a result of the calculation of maximum heating load based on the minimum ventilation rate in winter, the outdoor air temperature requiring heating was $6{\sim}7^{\circ}C$ to keep the indoor air temperature of chicken houses as $24^{\circ}C$. The peak cooling load of chicken houses was mostly taken by the heat generated by chickens and the heat gain due to ventilation. The heat gain through building envelopes was as small as neglectable. Most of chicken houses is usually cooled by gigantic forced ventilation in summer in Korea. When the chicken houses are cooled by electric cooling machine such as cooler or air conditioner, it is more effective to keep minimum ventilation rate to reduce the maximum cooling load. To lower the temperature of supplying water to cooling pad, it is recommended to use the underground water below 10 meters from the ground if there is abundant underground water.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.160-168
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• 2021

This study was undertaken to determine the effect of different cooling systems on the performance and hair cortisol of sows under heat stress. During a 21-day experiment, a total of 40 multiparous sows (Landrace×Yorkshire; 242.84±2.89 kg) were allotted to 4 treatments, each with 10 replicates (1 sow per pen). The experimental treatments were CP (Cooling pad), AC (Air conditioner), SC (Snout cooling), and MS (Mist spray). We observed an increase in the average daily feed intake during lactation (p<0.05) in the CP and AC treatment groups. AC treatment had the highest (p<0.05) and SC treatment had the lowest (p<0.05) piglet weight at weaning. During lactation, sows administered SC and MS treatments had higher (p<0.05) hair cortisol accumulation, as compared with the AC and CP treatments. Hair cortisol accumulation in piglets during lactation was highest with MS treatment (p<0.05), and lowest after CP treatment (p<0.05). MS treatment had the highest (p<0.05), and AC treatment had the lowest (p<0.05) respiratory rate and rectal temperature during lactation. In conclusion, our results indicate that a cooling pad and air conditioning cooling system increases the productivity of a sow, as compared to snout cooling and mist spray cooling systems.

• Journal of Animal Science and Technology
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• v.64 no.4
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• pp.782-791
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• 2022

The purpose of this study is to evaluate the effects of multiple cooling systems and different drinking water temperatures (DWT) on the performance of sows and their hair cortisol levels during heat stress. In this study, the effect of four different cooling systems: air conditioner (AC), cooling pad (CP), snout cooling (SC), and mist spray (MS), and two DWT, namely low water temperature (LWT) and high water temperature (HWT) on 48 multiparous sows (Landrace × Yorkshire; 242.84 ± 2.89 kg) was tested. The experiment is based on the use of eight replicas during a 21-days test. Different behaviors were recorded under different cooling treatments in sows. As a result, behaviors such as drinking, standing, and position change were found to be lower in sows under the AC and CP treatments than in those under the SC and MS treatments. Lying behavior increased under the AC and CP systems as compared with that under the SC and MS, systems. The average daily feed intake (ADFI) in sows and weight at weaning in piglets was higher under the AC, CP, and LWT treatments than under the SC, MS and HWT treatments. Sows subjected to SC and MS treatment showed higher hair cortisol levels, rectal temperature, and respiratory rate during lactation than those under AC and CP treatments. Hair cortisol levels, rectal temperature, and respiratory rate were also higher under the HWT than under the LWT treatment. As per the results of this study, the LWT has no significant effect on any of the behavioral factors. Taken together, the use of AC and CP cooling treatment is highly recommended to improve the behavior and to reduce the stress levels in lactating sows.

• Journal of the Korean Institute of Gas
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• v.18 no.3
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• pp.38-43
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• 2014

This paper is to analyze and study the failure examples of fire by inflammables and electric contact faulty in interior of vehicle. The first example, the driver used to air freshener that remove the air conditioner bad smell. He get out of a car. And then, he put it on the crash pad. Before long, a fire breaks out because of explosion solar radiation. The second example, the driver used in room of a car. It certified the fire by disconnection phenomenon happened the electric overload. The third example, the driver install the heat rays to warm his body, In the initial stages, it didn't seek the dangerous of fire during using a car to 5,000km. This heat rays become to down durability so that produced the electric overload in an instant. The fourth example, after the man smoked the cigarette on riding with rear seat, he put it on seat in vehicle no extinguishing the burning cigarette. It knew the fact that burnt to ashes a car by on well combustible paper. Thus, the driver must consider a countermeasure for minimize the fire production when he use the inflammable and install adding electric system.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.1
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• pp.18-25
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• 2023

We present the case of a 65-year-old man with maxillary and mandibular complete dentures prepared using neutral zone technique after undergoing mandibulotomy due to tonsil cancer 10 years ago. The patient had a short edentulous period; hence, there was minimal absorption of the alveolar ridge and no abnormality in the motor function of the tongue. However, the retromolar pad was located inside the hamular notch, and the posterior alveolar ridge was relatively turned inward. If the artificial teeth would have been aligned conventionally, the functional space of the tongue would have been invaded, which would have moved the tongue posteriorly thereby reducing the stability of the denture. Therefore, applying the concept of the neutral zone can be a good reference point in such cases. The neutral zone was registered using tissue conditioner, and tooth alignment was performed by making a silicone putty index. The biggest advantage of using neutral zone concept is denture stability. In this case, the neutral zone technique was applied to obtain the lingual alignment limit of the posterior teeth to avoid invasion of the tongue space by the left posterior part of the mandible. Particularly, in case of a patient in which denture stability is difficult to obtain due to absorption of the alveolar ridge, it is believed that better results can be obtained using neutral zone technique.