• Journal of the Korea Convergence Society
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• v.9 no.6
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• pp.69-75
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• 2018

Efficiency of Process in manufacturing industry is a critical factor to connect directly to competitiveness of product. In particular, due to FTAs with various worlds around the world, the domestic and overseas manufacturing industries are facing intense competitions, and it requires elaborate task management system for shortening production time. This study aims at seeking how to raise efficiency of manufacturing process, using motion analysis solution. When improving the process of manufacturing after verifying optimization using motion analysis solution, it can save costs for additional process, modification, or supplement. It can also deduce practical effect to improve productivity of companies. It is expected that the study will contribute to improve wastes in the work field and task assignment efficiency, to shorten time replacing equipment, to measure standard time, and to standardize task system.

• The Journal of Bigdata
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• v.3 no.1
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• pp.95-103
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• 2018

In recent years, many people in the manufacturing field have been making efforts to increase efficiency while analyzing manufacturing data generated in the process according to the development of ICT technology. In this study, we propose a data mining based manufacturing process using decision tree algorithm (CHAID) as part of a smart factory. We used 432 sensor data from actual manufacturing plant collected for about 5 months to find out the variables that show a significant difference between the stable process period with low defect rate and the unstable process period with high defect rate. We set the range of the stable value of the variable to determine whether the selected final variable actually has an effect on the defect rate improvement. In addition, we measured the effect of the defect rate improvement by adjusting the process set-point so that the sensor did not deviate from the stable value range in the 14 day process. Through this, we expect to be able to provide empirical guidelines to improve the defect rate by utilizing and analyzing the process sensor data generated in the manufacturing industry.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.6
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• pp.613-620
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• 2010

This study focused on the improvement of field investigation process of digital mapping by location-based image data and structured digital map. We analyzed previous methods to find the parts to be improved and suggested new methods. Main concepts of new methods are conducting investigation work indoor and linked the work with map editing for carrying out both work simultaneously by using location-based image data and structured digital map. Pilot project were carried out to compare suggested new methods with previous methods and the applicability were analyzed.

• Journal of Korea Multimedia Society
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• v.10 no.1
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• pp.83-93
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• 2007

WFQ (Weighted Fair Queuing) is the most popular fair queuing algorithm, but it had the inherent drawback of a poet bandwidth utilization, particularly under the traffic requiring a low rate but tight delay bound such as internet phone. It was recently identified that the poor utilization is mainly due to the non-optimized latency of a flow and then LOFQ(Latency-Optimized Fair Queuing) to overcome the drawback was introduced. In this paper, we improve the performance of LOFQ by introducing an occupied resource optimization function and reduce the implementation complexity of recursive resource transformation by revising the transformation scheme. We also prove the superiority of LOFQ over WFQ in terms of utilization. The simulation result shows that the improved LOFQ provides $20{\sim}30%$ higher utilization than that in the legacy LOFQ.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.11
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• pp.1407-1413
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• 2019

In this paper, we assume that another transmitter can transmit its data signal in the same frequency band in order to maximize the frequency efficiency of non-orthogonal multiple access(NOMA) systems. We also focus on the improvement in fairness performance of receiver's data rates, not the maximization of sum data rate for NOMA systems. Thus, in this paper, we propose a power allocation scheme to enhance the fairness performance of average data rates of receivers considering the NOMA systems in the presence of interference. Assuming Rayleigh fading channels, the average data rates of receivers are defined, and the power allocation coefficients to improve the data-rate fairness are derived by using high signal-to-noise power ratio approximation. In addition, through simulations, it is shown that the proposed power allocation scheme can improve the data-rate fairness in the NOMA system with interference.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.271-277
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• 2012

The purpose of this study is to increase productivity through decreasing defect ratio and improving product process. This study finds optimal temperature and pressure at Injection by experiment design and improves acrylic plate cast to increase productivity. In this study, there are some benefits such that Cycle time decreases to 51 (sec) from 70(sec), Operating Defect Ratio decreases to 0.5% from 20% and Cost of Production decreases to 201(won) from 240(won).

• Clean Technology
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• v.3 no.2
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• pp.57-73
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• 1997

Metal cleaning process is a technology which removes oil, dust and soil etc. on the surface of metal utilizing cleaning agents. These contaminants disturb the following processes such as plating and painting etc. if they are not removed. Thus, metal cleaning is typically an environmentally hazardous activity. Until recently, vapor degreasers as utilizing chlorinated solvents have been relatively cheap, extraordinarily versatile and waste disposal costs have been perceived as insignificant. Today, however, it is readily apparent that Industry's reliance upon chlorinated solvents as metal cleaners have resulted in a myriad of environmental, health and safety concerns. Therefore, this paper studies on a parameter and a sort of the alternative cleaning agents for the optimum cleaners. Also, a great deal of effort has been devoted to developing alternative metal cleaning technologies in advanced countries and some processes are being commercialized among them. We are going to consider alternative aqueous cleaning agents replacing organic chlorinated solvents and to pursue a domain application through a successful improvement case.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.113-113
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• 2010

유비쿼터스 시대를 맞이하여 현재의 전자제품은 초고주파 환경에서의 소형화된 마이크로파 소자를 요구하고 있다. 마이크로파 대역에서 세라믹 소재는 대부분의 폴리머 소재에 비해 낮은 유전손실 값을 보이고 있어 향후 확대되는 고주파화에 적합한 소재로 평가되고 있다. 하지만 세라믹 재료는 깨지기 쉬운 특성을 가지고 있어 공정 및 취급이 어려우며 높은 소결온도를 가지고 있어 융점이 낮은 재료와의 집적화에 있어서 난점을 가지고 있다. 이를 위해 본 연구실에서는 실온에서 세라믹을 비롯한 금속 및 폴리머 재료의 치밀한 코팅막의 성막 및 이종 접합이 가능한 Aerosol Deposition (AD 법)에 주목하였고 마이크로파 소자 제작 공정으로서 AD 법의 응용 가능성을 연구하였다. 마이크로파 소자의 기판으로서는 AD 법을 이용하여 유전손실이 낮고 플렉서블한 $Al_2O_3$-PTFE 혼합 기판을 제작하고 적용하였다. 금속 선로 패터닝 제작 공정으로는 도금법이 대표적이지만 고비용 및 복잡한 공정 절차, 폐화학용액으로 인한 환경문제 등의 단점을 지니고 있어 이를 대체하는 금속 선로 패터닝 공정이 절실히 요구되고 있다. 이를 위해 본 연구에서는 AD 법을 이용하여 금속 필름을 제작하고 대체 공정으로서의 가능성을 확인하였다. 하지만 AD 법을 이용한 세라믹 필름 제작에 관한 연구는 크게 활성화되어 있는 반면에 금속 필름의 제작, 특성 측정 및 개선에 관한 연구는 그에 비해 미비한 수준이다. 이를 위해 이번 연구에서는 AD 법을 이용하여 금속 필름을 성막 시에 영향을 미치는 요인을 고찰하였으며 또한 마이크로파 소자의 도체 손실에 크게 관계되는 금속 필름의 비저항 특성의 측정 및 개선에 관한 연구를 수행하였다. 이를 위해 본 연구에서는 정전장 시뮬레이션을 활용하여 AD 법으로 성막된 금속 필름의 정밀한 비저항 측정에 관한 연구방법을 마련하고 후열처리를 통한 비저항 특성을 개선시키는 연구를 진행하였다.

• Applied Chemistry for Engineering
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• v.16 no.5
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• pp.620-627
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• 2005

In this study, life cycle assessment (LCA) on one of corrugated cardboard box as functional unit was carried out. System boundary of this study divided according to raw material acquisition, corrugated cardboard manufacture and corrugated cardboard box manufacture stage. And environmental impacts are evaluated on each stage and sub-process. The impact categories are classified into eight categories of abiotic resource depletion, global warming stratospheric ozone depletion, photochemical oxidant creation, air acidification, eutrophication, ecotoxicity and human toxicity. From the results, it is found that environment impacts at raw material acquisition stage is the highest as about 92% of whole stage due to liner board manufacture stage. The highest environmental impacts at sub-process of corrugated cardboard and box manufacture stage is a single facer and D/W backer process that included as main process in corrugated cardboard manufacture, and is caused by used energies like electricity, B-C oil, and etc. And then diagnosis for clean production process system of package is carried out. Through diagnosis, on loss rate is reduced and inner pressure intensity of box is improved. After improvement, environmental impact was decreased about 3.8% compared with before improvement.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.1020-1025
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• 2004

In previous paper, contaminations of food-borne pathogenic bacteria of Saengshik was found to occur during processing, because detection rates of food-borne pathogenic bacteria in final products were higher than those of raw materials. In this study, methods to reduce food-borne pathogenic bacteria and improved manufacturing process were developed for microbial safety of Saengshik. Food-borne pathogenic bacteria in raw materials were reduced to about 0.5-2.0 log cfu/g when seven kinds of raw materials were washed with electrolyzed water and ozonated water, but food-borne pathogenic bacteria could not be removed completely. After improvement of manufacturing process, numbers of food-borne pathogenic bacteria were same or decreased to levels of raw materials. Gaseous ozone and Biocon could control air-borne bacteria under $1{\times}10^1$ cfu/1000 L of air in pulverization and mixing rooms.