• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.5933-5938
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• 2014

In this study, the effect of varying the mixture gas during FCA welding was studied for an Atos 60 test piece. To examine the characteristics of welding, the weldability of the material was checked before welding and online monitoring was performed to examine the mechanical properties after welding. The mixture Ar 80% + $CO_2$ 20% at low speed gave very elegant beads with very little spatter. 100% $CO_2$ gave rise to high spatter generation. For Ar 80% + $CO_2$ 20%, the low current region due to the normal short circuits created spatter, which was more than double for 100% $CO_2$. This peak distribution occurred due to the instability of the arc. The tensile test result for Ar 80% + $CO_2$ 20%, Ar 90%+ $CO_2$ 10% and $CO_2$ 100% at 511MPa, 507MPa, and 469MPa showed that the yield strength was improved by 8.1 and 8.9% for 80%+ $CO_2$ 20% and Ar 90%+ $CO_2$ 10%, respectively, compared to 100% $CO_2$. The tensile test result at 622MPa, 609MPa, and 581MPa showed that the yield strength was improved by 7.0% for both the mixture gas compared to 100% $CO_2$.

• The Korean Journal of Applied Statistics
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• v.34 no.5
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• pp.795-806
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• 2021

Recently, as text data through online channels have become vast, there is a growing interest in research that summarizes and analyzes them. One of the fundamental analyses of text data is to extract potential topics. Although the researcher may read all the data and summarize the contents one by one, it is not easy to deal with large amounts of data. Blei and Lafferty (2007) and Blei et al. (2003) proposed topic modeling methods for extracting topics using a statistical model. Since the text data is generally collected over time, it is worthwhile to monitor the topic's changes. In this study, we propose a topic index based on the results of the topic model. In addition, a control chart, a representative tool for statistical process management, is applied to monitor the topic index over time. As a practical example, we use text data collected from Blue House National Petition boards between March 5, 2018, and March 5, 2020.

• Korean Journal of Remote Sensing
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• v.39 no.5_4
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• pp.1075-1084
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• 2023

Satellite-derived data is collected by observing the Earth and is used in various fields such as national defense, natural disasters, location-based services, infrastructure, environment, energy, marine, and insurance. This study aims to present the virtuous cycle structure of the satellite information data industry and the business ecosystem model of the industry. As a research method, cases were collected and categorized from the following areas: literature, online, application, and content. The results show that the ecosystem model of the satellite information data industry provides an approach to content services in public and commercial areas, and develops various algorithmic technologies to facilitate content production and services at the level of complex general-purpose technologies. Second, in terms of content typology, satellite information data can be subdivided into monitoring content, urban space monitoring content, and satellite information content. Third, the consumption value of satellite content could be subdivided into informational value, environmental, social and governance (ESG) value, educational value, and content value. In order to expand the global content market, Korea will need to focus on creating an ecosystem for the satellite information industry and discovering differentiated content. It will also need to increase the popularization and accessibility of data to the general public and promote the Korean K-Satellite Information Data Industry ecosystem through government support, policy efforts, and policies such as establishing legal systems, increasing investment, and training human resources.

• Journal of Technology Innovation
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• v.23 no.4
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• pp.151-175
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• 2015

The general public is a key stakeholder in the science and technology domain. However, traditional approaches require substantial efforts and resources to analyze how does the general public understand science and technology issues. We applied the topic modeling, a form of text clustering, to the texts about the nuclear power which were posted on an online space in order to explore the general public's thoughts on the issue. This study investigates the extent to which macro-level events influence understandings of the general public on the science and technology issues and weather these changes in understandings are sustained over time. It examines the possibility of applying topic modeling in narrowing a perception gap between the general public and the experts through a near-real-time monitoring of the public interests and perceptions about the science and technology issues.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.266-266
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• 2009

This paper describes important parameters used to evaluate the insulation performance of power supply components in metro substations. For online fault diagnosis of power supply components, we have developed a new remote condition monitoring system using wireless technology. Our developed system can continuously monitor electric power equipment such as transformers, circuit brakers, and rectifiers and have powerful wireless networking functions.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.539-542
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• 2003

A motor is the workhorse of our industry. The issues of preventive and condition-based maintenance, online monitoring, system fault detection, diagnosis, and prognosis are of increasing importance. Different internal motor faults (e.g., inter-turn short circuits, broken bearings, broken rotor bars) along with external motor faults (e.g., phase failure, mechanical overload, blocked rotor) are expected to happen sooner or later. This paper introduces the fault detection technique of induction motors based upon the stator current. The fault motors have rotor bar broken or rotor unbalance defect, respectively. The stator currents are measured by the current meters and stored by the time domain. The time domain is not suitable to represent the current signals, so the frequency domain is applied to display the signals. The Fourier Transformer is used for the conversion of the signal. After the conversion of the signals, the features of the signals have to be extracted by the signal processing methods like a wavelet analysis, a spectrum analysis, etc. The discovered features are entered to the pattern classification model such as a neural network model, a polynomial neural network, a fuzzy inference model, etc. This paper describes the fault detection results that use wavelet decomposition. The wavelet analysis is very useful method for the time and frequency domain each. Also it is powerful method to detect the features in the signals.

• Korean Journal of Clinical Pharmacy
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• v.25 no.4
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• pp.280-285
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• 2015

Objectives: To suggest direction for improving policies by understanding current management of narcotics or psychotropic drugs and analyzing their distributions and usage. Method: We conducted a comparison analysis between health insurance claims and the amount supplied to health care institutions for narcotics or psychotropic drugs through health insurance claims data and drug distribution supply data from 2010 to 2012 collected from Korea Pharmaceutical Information Service Center (KPIS). Furthermore, we carried out literature investigation and online search to comprehend the current management of narcotics drugs in Korea. Results: The amount supplied to medical institutions for all drugs in 2012 was 19.4 trillion won, which increased from 19.5 trillion in 2011 by 0.54%. For narcotic drugs, the amount supplied was 318.4 billion won in 2011 and increased to 335.1 billion won by 5.3% in 2012, which exceeded the rate of increase for the amount supplied for all drugs. The proportion of amount claimed in the total amount supplied to medical institutions for all drugs was 60.5% in 2012, whereas the proportion of amount claimed for narcotic drugs was 55.6%, which showed that narcotic drugs were used relatively less within health insurance. Furthermore, management of the current domestic distribution supply data focuses on manufacturing and medical institution supply stages. Conclusion: Hereafter, the management of narcotics or psychotropic drugs needs to be improved by reinforcing active monitoring in optimal prescription and usage in patients by collecting and analyzing information on drug usage of patients.

• ALGAE
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• v.35 no.3
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• pp.293-301
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• 2020

The applications of DNA barcoding have a wide range of uses, such as in taxonomic studies to help elucidate cryptic species and phylogenetic relationships and analyzing environmental samples for biodiversity monitoring and conservation assessments of species. After obtaining the DNA barcode sequences, sequence similarity-based homology analysis is commonly used. This means that the obtained barcode sequences are compared to the DNA barcode reference databases. This bioinformatic analysis necessarily implies that the overall quantity and quality of the reference databases must be stringently monitored to not have an adverse impact on the accuracy of species identification. With the development of next-generation sequencing techniques, a noticeably large number of DNA barcode sequences have been produced and are stored in online databases, but their degree of validity, accuracy, and reliability have not been extensively investigated. In this study, we investigated the extent to which the amount and types of erroneous barcode sequences were deposited in publicly accessible databases. Over 4.1 million sequences were investigated in three largescale DNA barcode databases (NCBI GenBank, Barcode of Life Data System [BOLD], and Protist Ribosomal Reference database [PR2]) for four major DNA barcodes (cytochrome c oxidase subunit 1 [COI], internal transcribed spacer [ITS], ribulose bisphosphate carboxylase large chain [rbcL], and 18S ribosomal RNA [18S rRNA]); approximately 2% of erroneous barcode sequences were found and their taxonomic distributions were uneven. Consequently, our present findings provide compelling evidence of data quality problems along with insufficient and unreliable annotation of taxonomic data in DNA barcode databases. Therefore, we suggest that if ambiguous taxa are presented during barcoding analysis, further validation with other DNA barcode loci or morphological characters should be mandated.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.2820-2827
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• 2015

HSMS communication system using low-cost micro controller units(MCUs) is an essential technique for online semiconductor equipment system developments. It is intended as an alternative to SEMI E4 (SECS-I) for applications where higher speed communication is needed and the facilitated hardware setup is convenient. In this paper, an HSMS communication system using low-cost MCUS is designed and implemented. Using a MCU with a low price but high-performance as a main board, a module which processes HSMS communication is designed, and a circuit is designed to process BCR independently with a microminiature MCU. To convert tag data which is recognized from BCR into data based on HSMS communication protocol, SECS-II message is designed. Lastly, an HSMS communication system is implemented based on these designs. A low-cost HSMS communication module developed in this study can be applied in realtime monitoring and controlling system for semiconductor processes.

• Journal of Microbiology and Biotechnology
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• v.30 no.6
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• pp.868-877
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• 2020

Bicarbonate has been considered as a better approach for supplying CO₂ to microalgae cells microenvironments than gas bubbling owing to cost-effectiveness and easy operation. However, the β-carotene production was too low in Dunaliella salina cultivated with bicarbonate in previous studies. Also, the difference in photosynthetic efficiency between these two carbon sources (bicarbonate and CO₂) has seldom been discussed. In this study, the culture conditions, including NaHCO₃, Ca²⁺, Mg²⁺ and microelement concentrations, were optimized when bicarbonate was used as carbon source. Under optimized condition, a maximum biomass concentration of 0.71 g/l and corresponding β-carotene content of 4.76% were obtained, with β-carotene yield of 32.0 mg/l, much higher than previous studies with NaHCO₃. Finally, these optimized conditions with bicarbonate were compared with CO₂ bubbling by online monitoring. There was a notable difference in F_v/F_m value between cultivations with bicarbonate and CO₂, but there was no difference in the F_v/F_m periodic changing patterns. This indicates that the high concentration of NaHCO₃ used in this study served as a stress factor for β-carotene accumulation, although high productivity of biomass was still obtained.