• Journal of Life Science
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• v.28 no.5
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• pp.627-637
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• 2018

Motility and chemotaxis are crucial for disease development in many motile pathogens, including spirochetes. In many bacteria, motility is provided by flagella rotation, which is controlled by a chemotaxis-signal-transduction system. Thus, motility and chemotaxis are inextricably linked. Spirochetes are a unique group of bacteria with distinctive flat-wave morphology and corkscrew-like locomotion. This unusual motility pattern is believed to be important for efficient motility within the dense tissues through which these spirochetes preferentially disseminate in a host. Unlike other externally flagellated bacteria-where flagella are in the ambient environment-the flagella of spirochetes are enclosed by the outer membrane and thus are called periplasmic flagella or endoflagella. Although motilityand chemotaxis-associated genes are well studied in some bacteria, the knowledge of how the spirochete achieves complex swimming and the roles of most of the putative spirochetal chemotaxis proteins are still elusive. Recently, cutting-edge imaging methods and unique genetic manipulations in spirochetes have helped to unravel the mystery of motility and chemotaxis in spirochetes. These contemporary advances in understanding the motility and chemotaxis of spirochetes in a host's persistence and disease process are highlighted in this review.

• Journal of the Korea Society of Computer and Information
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• v.25 no.8
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• pp.181-188
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• 2020

In this study, we propose a comparative study to confirm the impact of various word embedding techniques on the performance of sentiment analysis. Sentiment analysis is one of opinion mining techniques to identify and extract subjective information from text using natural language processing and can be used to classify the sentiment of product reviews or comments. Since sentiment can be classified as either positive or negative, it can be considered one of the general classification problems. For sentiment analysis, the text must be converted into a language that can be recognized by a computer. Therefore, text such as a word or document is transformed into a vector in natural language processing called word embedding. Various techniques, such as Bag of Words, TF-IDF, and Word2Vec are used as word embedding techniques. Until now, there have not been many studies on word embedding techniques suitable for emotional analysis. In this study, among various word embedding techniques, Bag of Words, TF-IDF, and Word2Vec are used to compare and analyze the performance of movie review sentiment analysis. The research data set for this study is the IMDB data set, which is widely used in text mining. As a result, it was found that the performance of TF-IDF and Bag of Words was superior to that of Word2Vec and TF-IDF performed better than Bag of Words, but the difference was not very significant.

• Membrane Journal
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• v.30 no.4
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• pp.228-241
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• 2020

Separators, which produces physical layer between a cathode and anode, are getting enormous attention as the quality of the separator determines the performance of lithium ion batteries (LIBs). Porous membranes based on polyethylene (PE) and polypropylene (PP) are generally utilized as the separator of LIBs because of their high electrochemical stability and suitable mechanical strength. However, low thermal resistance and wettability of PE and PP membranes limited the potential of LIBs. Operating at the temperature exceeding the melting point of membranes, the separators change their structures which lead to short circuit of LIBs. Low wettability of the separators corresponds to low ionic conductivity which increases the cell resistance. To overcome these weaknesses of PE and PP separators, different types of separator were prepared by co-electrospinning, applying coating layer, forming core shell around membrane, and papermaking method. The synthesized separator greatly enhanced the heat resistance and wettability of separator and mechanical properties like flexibility and tensile strength. In this review different type of polymer membrane used as separator in lithium ion battery are discussed.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.2
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• pp.143-165
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• 2016

The amount of greenhouse gas emission reduction based on INDCs (Intended Nationally Determined Contributions) submitted to UN by each party is not sufficient to achieve the Paris Agreement's aim to "hold the increase in the global average temperature to well below $2^{\circ}C$ above pre-industrial levels and to pursue efforts to limit the temperature increase to $1.5^{\circ}C$" which was determined in the $21^{st}$ Conference of the Parties to the UNFCCC (COP 21). Accordingly, the emission reduction target of each party will be revised for the $2^{\circ}C$ goal. Among the several options to reduce the carbon emission, CCS (Carbon Capture and Storage) is a key option to curb $CO_2$ emissions from large emission sources such as fossil-based power plants, cement plants, and steel production plants. A large scale CCS demonstration projects utilizing $1^{st}$ generation $CO_2$ capture technologies are under way around the world. It is anticipated, however, that the deployment of those $1^{st}$ generation $CO_2$ capture technologies in great numbers without government support will be difficult due to the high capture cost and considerable increase of cost of electricity. To reduce the carbon capture cost, $2^{nd}$ and $3^{rd}$ generation technologies are under development in a pilot or a bench scale. In this paper, current status of large scale CCS demonstration projects and the $2^{nd}$ and $3^{rd}$ generation capture technologies are summarized. Novel capture technologies on wet scrubbing, dry sorbent, and oxygen combustion are explained in detail for all capture areas: post-combustion capture, pre-combustion capture, and new combustion technologies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7485-7493
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• 2015

With the popularity of Korean Wave, making cultural goods specific for Hallyu tourists is getting more important. However, there are mainly daily life goods using celebrity character-based ones. Remarkably, there are only a few cultural goods especially in practicality-based clothing category. In particular, few cultural goods related to children's wear have been developed. Therefore, if children's wear is developed as Korean Wave cultural goods considering Chinese consumers' pattern and Korean Wave cultural goods, it will be helpful for revitalizing the Korean Wave and Korea's fashion market. In this regard, the purpose of this study is to develop children's wear design as Korean Wave cultural goods, thereby presenting empirical research results and fulfilling its following objectives: First, it is to identify the concept of Korean Wave cultural goods, to analyze the current status to finally establish data to develop Korean Wave cultural goods needed at this time. Second, it is to make real-life size works through development of designs to provide the empirical data for Korean Wave cultural goods market. For the research method and contents the review of the previous research, in-depth interview for qualitative research, and empirical research using market research and development of work were performed. Through the final research outcomes, Korean Wave cultural goods, the children's wear that can meet the consumer's needs were presented as empirical data. The study can be used as basic data for domestic fashion market and cultural product market and it is meaningful as a reference for the analysis on the Chinese consumers' needs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.99-105
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• 2017

With the advancement of Information and Communication Technology (ICT), the wearable-device industry is growing at a rapid pace in line with the hyper-connected society of people-to-things and things-to-things network connections. International Data Corporation (IDC), a market research institute, estimates that the wearable-device industry will grow rapidly by 2020, despite not yet attracting a popular response. This study investigates the trend of the wearable-device industry and draws implications for product and service development through user experience analysis. The subject of analysis was smart bands and the data generated from product review were collected and analyzed. As a result, user experience could extract utility, usability, aesthetics, value, and reliability, and polarity was analysed and visualized in the extracted data. The study results reveal that current wearable-devices are expensive, that users cannot receive useful information from the long-term viewpoint since the analysis of accumulated data remains focused on functional development, and that they are recognized as a fashion item or an accessory. These factors hinder the continuous usage, motivation and market spread of the product. In a future follow-up study, we will conduct a comparative study on bands and watches by analyzing the second smart watch.

• Korean Journal of Remote Sensing
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• v.35 no.5_1
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• pp.737-750
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• 2019

Information of target changes in inaccessible areas is very important in terms of national security. Fast and accurate change detection of targets is very important to respond quickly. Spaceborne synthetic aperture radar can acquire images with high accuracy regardless of weather conditions and solar altitude. With the recent increase in the number of SAR satellites, it is possible to acquire images with less than one day temporal resolution for the same area. This advantage greatly increases the availability of change detection for inaccessible areas. Commonly available information in satellite SAR is amplitude and phase information, and change detection techniques have been developed based on each technology. Those are amplitude Change Detection (ACD), Coherence Change Detection (CCD). Each algorithm differs in the preprocessing process for accurate automatic classification technique according to the difference of information characteristics and the final detection result of each algorithm. Therefore, by analyzing the academic research trends for ACD and CCD, each technologies can be complemented. The goal of this paper is identifying current issues of SAR change detection techniques by collecting research papers. This study would help to find the prerequisites for SAR change detection and use it to conduct periodic detection research on inaccessible areas.

• The Journal of the Korea Contents Association
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• v.19 no.10
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• pp.397-406
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• 2019

The purpose of this study was to develop the evaluation scale according to the major selection attribute of culinary major students. For the scale development, 69 items were extracted through theoretical review. After that, a survey was conducted on 73 students who are currently studying culinary majors, and two culinary majors and three culinary major professors conducted in-depth analysis and refining. The questionnaire was conducted from March 18 to March 27, 2019, and the second expert group survey was conducted from August 19 to August 31, 2019 based on Kendall's W-validated mean and standard deviation. The results of this study are as follows. First, 46 properties were derived from the first expert group survey. Second, six factors and 32 attributes were derived through consultation with the second and third expert groups. Thirdly, through the verification of Kendall's W attributes of 32 six factors, verification of consensus on the importance of experts was made, and the final four factors (individual factors, occupational factors, major characteristics factors, and university-related factors) were derived. It was. The results of this study suggest that the final composition of the culinary major selection attribute is expected to contribute enough to increase student satisfaction, school loyalty, and enrollment rate of students through the measurement scale to grasp the competitiveness of the culinary major.

• Journal of Life Science
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• v.31 no.9
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• pp.849-855
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• 2021

Recently, as nanotechnology has been introduced and used in various fields, the development of new drugs has been accelerating. Nanoparticles have maintained blood drug concentration for extended periods of time with a single administration of the drug. The drug can then be selectively released only at the pathological site, thereby reducing side effects to other non-pathological sites. In addition, nanoparticles can be modified for selective target sites delivery for other specific diseases, with polymers being widely used in the manufacture of these nanoparticles. Poly (D,L-lactic-co-glycolic acid ) (PLGA) is one of the most extensively developed biodegradable polymers. PLGA is widely used in drug delivery for a variety of applications. It has also been approved by the FDA as a drug delivery system and is widely applied in controlled release formulations, such as in gene therapy treatments. PLGA nanoparticles have been developed as delivery systems with high efficiency to specific cell types by using passive and active targeting methods. After the development of a drug delivery system using PLGA nanoparticles, the drug is selectively delivered to the target site, and the effective blood concentration for extended periods of time is optimized according to the disease. In this review paper, we focus on ways to improve cell-specific treatment outcomes by examining the development of astrocyte selective nanoparticles based on PLGA nanomaterials for gene therapy.

• The Journal of the Korea Contents Association
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• v.21 no.9
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• pp.176-183
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• 2021

Digital medical technology is very effective and at the same time faces the challenge of protecting privacy. However, for contact tracking and exposure notification apps in COVID-19 environment, there is always a trade-off between privacy measures and the effectiveness of the app's use. Today, many countries have developed and used contact tracking and exposure notification apps in various forms to prevent the spread of COVID-19, but the suspicion of digital surveillance (digital panopticon) is unavoidable. Therefore, this study aims to identify the factors of personal information infringement and dissatisfaction through text mining analysis by extracting user reviews of "Self-Quarantine Safety Protection" in Korea. As a result of the text mining analysis, we derived four groups, 'Address recognition error', 'Exit warning error', 'Access error', and 'App. program error'. Since 'Address recognition error' and 'Exit warning error' can give the app users a strong perception that they are keeping under surveillanc by the app, transparent management of personal information protection and consent procedures related to personal information collection are required. In addition, if the other two groups are not corrected immediately due to an error in an app function or a program bug, the complaints of users can be maximized and a protest against the monitor can be raised.