• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2154-2159
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• 2007

The potential of using a double-faced wall stagnation flow burner in mass production of carbon nanotubes was evaluated experimentally and computationally. With nitrogen-diluted premixed ethylene-air flames established on the Nickel-coated stainless steel double-faced wall, the propensities of carbon nanotube formation were experimentally determined using SEM and FE-TEM images and Raman spectroscopy, while the flame structure was computationally predicted using a 3-dimensional CFD code with a reduced reaction mechanism. The uniformity and yields of synthesized carbon nanotubes were evaluated in terms of the flame stretch rates. Results show substantial increase of area on the wall surface where uniform carbon nanotubes are synthesized with using the double-faced wall stagnation flow burner due to enhanced uniformity of temperature distribution along the wall surface and support the potential of using a double-faced wall stagnation flow burner in mass production of carbon nanotubes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권2호
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• pp.841-854
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• 2020

The paper explains the method to process, analyze and predict traffic patterns in Los Angeles county using Big Data and Machine Learning. The dataset is used from a popular navigating platform in the USA, which tracks information on the road using connected users' devices and also collects reports shared by the users through the app. The dataset mainly consists of information about traffic jams and traffic incidents reported by users, such as road closure, hazards, accidents. The major contribution of this paper is to give a clear view of how the large-scale road traffic data can be stored and processed using the Big Data system - Hadoop and its ecosystem (Hive). In addition, analysis is explained with the help of visuals using Business Intelligence and prediction with classification machine learning model on the sampled traffic data is presented using Azure ML. The process of modeling, as well as results, are interpreted using metrics: accuracy, precision and recall.

• 한국수학사학회지
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• 제28권1호
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• pp.15-29
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• 2015

This study aims to analyze how the history of mathematics is used in Chinese mathematics textbooks. As a framework for analysis, we categorized nine types of using the history of mathematics in textbooks. We analyzed 18 mathematics textbooks for Chinese elementary and middle schools. As a result, we found that various types of using the history of mathematics were adopted in Chinese textbooks except for explorations of mathematical errors in history. We also noticed three characteristics: preference to using for motivation and reading matters in elementary school levels, high frequencies of using problems from traditional mathematical books and origins of mathematical concepts or symbols, and emphasis on ethnic superiority through the Chinese traditional mathematics. Based on the results of analysis, we discussed and induced some implications for using the history in our mathematics textbooks.

• 한국재료학회지
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• 제16권5호
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• pp.308-311
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• 2006

The purpose of this study is to investigate the difference of the wafer nanotopography impact on the oxide-film thickness variation between the STI CMP using ceria slurry and STI CMP using fumed silica slurry. The nanotopography impact on the oxide-film thickness variation after STI CMP using ceria slurry is 2.8 times higher than that after STI CMP using fumed silica slurry. It is attributed that the STI CMP using ceria slurry follows non-Prestonian polishing behavior while that using fumed silica slurry follows Prestonian polishing behavior.

• 수산해양교육연구
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• 제29권1호
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• pp.180-187
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• 2017

The purpose of this research is to analyze the relationship between using computer for learning and subjective achievement in high school. It is also to explore the relationship among gender, school type, subjective achievement and computer use for learning. We conduct structural equational modeling analyses using Korean Child Youth Panel Study (KCYPS) data with 1st grade middle school students panel. We found these results: (a) Using computer for learning effects on the subjective achievement of 3rd grade high school students. (b) Girls more use computer for the purpose of learning than boys during high school. (c) School type has an effect on using computer for learning in high school significantly. From these results, some strategies and guides are suggested in the use of computer for learning.

• 상하수도학회지
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• 제17권4호
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• pp.495-502
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• 2003

In order to modify incorrect flow data in the sewage system, the method using the stage-discharge relation and hydraulic characteristic curve of sewer pipe are applied. The modified data were verified with field measured data and the infiltration analysis using the modified data was carried out. When flowrate were measured using the flow-meter in fair weather, the stage data were comparatively consistent but velocity data were very poor for the most part. Therefore, it was recommended that sewage flowrate variation characteristic curve and infiltration were computed using the modified data on the basis of stage data. Especially, in the case of using the hydraulic characteristic curve, extrapolation results of the rainy season flowrate using regression curve on the basis of the data in fair weather were also reasonable.

• 음성과학
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• 제12권4호
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• pp.31-42
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• 2005

Recently, Gaussian Mixture Model (GMM), a special form of CHMM, has been applied to speaker identification and it has proved that performance of GMM is better than CHMM. Therefore, in this paper the speaker models based on GMM and a new GMM using the modified EM algorithm are introduced and evaluated for text-independent speaker identification. Various experiments were performed to evaluate identification performance of two algorithms. As a result of the experiments, the GMM speaker model attained 94.6% identification accuracy using 40 seconds of training data and 32 mixtures and 97.8% accuracy using 80 seconds of training data and 64 mixtures. On the other hand, the new GMM speaker model achieved 95.0% identification accuracy using 40 seconds of training data and 32 mixtures and 98.2% accuracy using 80 seconds of training data and 64 mixtures. It shows that the new GMM speaker identification performance is better than the GMM speaker identification performance.

• 전기전자학회논문지
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• 제18권2호
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• pp.234-239
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• 2014

This paper proposes a new automatic detection method to inspect mura defects on display film surface using morphological image processing and labeling. This automatic detection method for mura defects on display films comprises 3 phases of preprocessing with morphological image processing, Gabor filtering, and labeling. Since distorted results could be obtained with the presence of non-uniform illumination, preprocessing step reduces illumination components using morphological image processing. In Gabor filtering, mura images are created with binary coded mura components using Gabor filters. Subsequently, labeling is a final phase of finding the mura defect area using the difference between large mura defects and values in the periphery. To evaluate the accuracy of the proposed detection method, detection rate was assessed by applying the method in 200 display film samples. As a result, the detection rate was high at about 95.5%. Moreover, the study was able to acquire reliable results using the Semu index for luminance mura in image quality inspection.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.261-263
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• 1996

The study on the development of one-channel gas sensor using the quartz crystal analyzer were attempted. The adsorption and desorption behavior of organic gases were investigated using the resonant frequency and resistance method of quartz crystal. The sensitive materials were deposited on the quartz crystal analyzer(QCA) by using Langmuir-Blodgett method. To investigate the response characteristics of organic vapours and response mechanism, resonant frequency-resonant resistance (F-R) diagram was used. In our experimental results, the response mechanism between sensitive LB film and organic vapours was obtained using F-R diagram. And the position of each organic vapour were different as to the kind and injection amount. Thus F-R diagram can be applied to one-channel gas sensor using the QCA and useful to analyze the response mechanism between organic vspours and sensitive LB films.

• 가정과삶의질연구
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• 제27권1호
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• pp.31-44
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• 2009

The purpose of this study was to understand how consumers perceive the costs of using certain types of sales-promotions and to suggest ways in which sales-promotions should be developed to contribute to the consumers' welfare and the development of Marketing Strategy. The sufficiency of the consumers' desire was essential to new and creative sales-promotion strategy. This study investigated the perceived costs of using timely opportunity costs, extra expenses, substitution costs, uncomfortable feeling, regrets and economical and psychological satisfactions on certain types of sales-promotions such as off line, coupon, packed items, collection and on line, and event. In the study results on the perceived costs of using certain types of sales-promotions, off line sales-promotions were perceived more than substitution costs, extra expenses, regrets and on line sales-promotions were perceived more than timely opportunity costs. These results were caused by immediately using off line sales-promotions and becoming a member of on line sales-promotions. In the research result on the perceived costs of using certain types of sales-promotions and economical satisfactions, off line sales-promotions exhibited positive relations with substitution costs of coupon and extra expenses, regrets of packed items and collection about economical satisfactions. On line sales-promotions exhibited positive relations with extra expenses and regrets about economical satisfactions. The research results on the perceived costs of using certain types of sales-promotions and psychological satisfactions, off line sales-promotions exhibited positive relations with timely opportunity costs of coupon and collection about psychological satisfactions. On line sales-promotions exhibited positive relations with substitution costs about psychological satisfactions. These results were caused by the feeling of leisure time as the consumer played games or hobbies. This study proposes an approach in the context of sales-promotion with some suggestions and thoughts.