• Journal of Periodontal and Implant Science
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• v.50 no.2
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• pp.74-82
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• 2020

Purpose: The aim of this cross-sectional study was to investigate the effect of scaling and root planing (SRP) on the expression of anti-inflammatory cytokines (interleukin [IL]-4, IL-9, IL-10, and IL-13) in the gingival crevicular fluid (GCF) of electronic cigarette users and non-smokers with moderate chronic periodontitis (CP). Methods: Electronic cigarette users and non-smokers with CP were included in the study. Full-mouth plaque and gingival indices, probing depth (PD), clinical attachment loss (CAL), and marginal bone loss (MBL) were assessed. The GCF was collected, and its volume and levels of IL-4, IL-9, IL-10, and IL-13 were assessed. These parameters were evaluated at baseline and 3 months after SRP. The sample size was estimated, and comparisons between groups were performed. P<0.05 was considered to indicate statistical significance. Results: Thirty-six electronic cigarette users (47.7±5.8 years old) and 35 non-smokers (46.5±3.4 years old) with CP were included. At baseline, there were no differences in plaque index (PI), PD, CAL, MBL, and GCF IL-4, IL-9, IL-10, and IL-13 between electronic cigarette users and nonsmokers. At the 3-month follow-up, there were no significant differences in PI, gingival index (GI), PD, CAL, and MBL in electronic cigarette users compared to baseline, while there were significant reductions in PI, GI, and PD among non-smokers. At the 3-month follow-up, GCF IL-4, IL-9, IL-10, and IL-13 levels were significantly elevated in both groups (P<0.05) compared to baseline. The increases in GCF IL-4, IL-9, IL-10, and IL-13 levels were significantly higher in non-smokers (P<0.05) than in electronic cigarette users at the 3-month follow-up. Conclusions: Levels of GCF IL-4, IL-9, IL-10, and IL-13 increased after SRP in electronic cigarette users and non-smokers with CP; however, the anti-inflammatory effect of SRP was more profound in non-smokers than in electronic cigarette users.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.633-640
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• 2023

With the recent development of static and dynamic modulated brachytherapy methods in brachytherapy, which use radiation shielding to modulate the dose distribution to deliver the dose, the amount of parameters and data required for dose calculation in inverse treatment planning and treatment plan optimization algorithms suitable for new directional beam intensity modulated brachytherapy is increasing. Although intensity-modulated brachytherapy enables accurate dose delivery of radiation, the increased amount of parameters and data increases the elapsed time required for dose calculation. In this study, a GPU-based CUDA-accelerated dose calculation algorithm was constructed to reduce the increase in dose calculation elapsed time. The acceleration of the calculation process was achieved by parallelizing the calculation of the system matrix of the volume of interest and the dose calculation. The developed algorithms were all performed in the same computing environment with an Intel (3.7 GHz, 6-core) CPU and a single NVIDIA GTX 1080ti graphics card, and the dose calculation time was evaluated by measuring only the dose calculation time, excluding the additional time required for loading data from disk and preprocessing operations. The results showed that the accelerated algorithm reduced the dose calculation time by about 30 times compared to the CPU-only calculation. The accelerated dose calculation algorithm can be expected to speed up treatment planning when new treatment plans need to be created to account for daily variations in applicator movement, such as in adaptive radiotherapy, or when dose calculation needs to account for changing parameters, such as in dynamically modulated brachytherapy.

• Polymer(Korea)
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• v.26 no.5
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• pp.691-700
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• 2002

Interstitial therapy using biodegradable polymeric device loaded with anticancer agent can deliver the drug to the tumor site at high concentration, resulting in an increase of therapeutic efficacy. 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU, carmustine) is most commonly used as chemotherapeutic agent for brain tumors. The design of implantable device is regarded as an important factor lot the efficient delivery of antitumor agent to targeting site. In order to control the release profile of drug, the release pattern of BCNU with the changes of various dimension and additives was investigated. The PLGA wafers containing 3.85, 10, 20 and 30% of BCNU were prepared in various shape (diameter of 3, 5 and 10 mm, thickness of 0.5, 1 and 2 mm) by direct compression method. In vitro drug release profile of BCNU-loaded PLGA wafers could be controlled by changing the dimension of wafers such as initial drug content, weight, diameter, thickness, volume and surface area of wafers, as well as PLGA molecular weight and additives. Drug release from BCNU-loaded PLGA wafers was facilitated with an increase of BCNU-loading amount or presence of poly(N-vinylpyrrolidone)(PVP) or sodium chloride (NaCl). The effects of various geometric factors and additives on the BCNU release pattern were confirmed by the investigation of mass loss and morphology of BCNU-loaded PLGA wafers.

• Journal of Plant Biotechnology
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• v.37 no.1
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• pp.77-83
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• 2010

Eighteen cultivars of tomato were tested for their regeneration response. Lycopersicon esculentum cv. 2001-58 showed a very high frequency of regeneration (93%). We evaluated the effect of two compounds with known antioxidant activity (ascorbic acid and cystein). The use of ascorbic acid ($200\;-\;300\;{\mu}M/L$) has a positive effect on shoot regeneration. To develope a system for plastid transformation in tomato via homologous recombination, we constructed the tomato plastid expression vector (pKRT22-AG) harboring 2.2 kb flanking sequences cloned from intact plastid genome and gfp gene. To investigate the factors affecting the delivery system of the pKRT22-AG into chloroplast using bombardment, We assessed the optimal DNA concentration, gold particle volume and target distance. Expression of the GFP protein was observed within chloroplast on protoplast of cotyledon explant by confocal laser scanning microscopy, which indicates that the protocol developed in this study be useful for the production of plastid transgenic plants in tomato.

• Particle and aerosol research
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• v.18 no.3
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• pp.51-59
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• 2022

In this work, virion concentration and its dose changes by HVAC and air cleaners were estimated in a subway station platform to control airborne infection of SARS-CoV-2. Collection efficiencies with particle size were measured for the air filter equipped in a HVAC in one subway station in Daejeon. Indoor PM_2.5 changes according to outdoor PM_2.5 with time were also measured to estimate air infiltration rate in the subway station platform. When infected persons generate virions by 10⁴, 10⁵, 10⁶, 3 × 10⁶ and 5 × 10⁶ h^-1 in a 2,400 m³ volume platform, the concentration and dose were estimated as 9, 92, 275 and 458 virions/m³ and 4, 43, 130 and 217 virions after 1 hour exposure, respectively. The concentration and dose were reduced by 70%, and 64%, respectively by operations of both HVAC (with a flow rate of 16,000 m³/h, MERV 11) and ten air cleaners(with total CADR 10,740 m³/h) compared to those without operation of both HVAC and air cleaners. However, virion dose in the platform was estimated to be too low at the general conditions due to a large space, a high air infiltration (3 h^-1) and a short residence time (usually < 10 mins) in the platform irrespective of the operations of HVAC or air cleaners. HVAC with filters and air cleaners would be more necessary in the concourse or shopping areas in the subway stations to reduce the infection dose from a few hundred to several tens virions in a hour.

• The Journal of Bigdata
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• v.8 no.2
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• pp.149-163
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• 2023

Due to the continuous growth of the E-commerce market, the volume of orders that fulfillment centers have to process has increased, and various customer requirements have increased the complexity of order processing. Along with this trend, the operational efficiency of fulfillment centers due to increased labor costs is becoming more important from a corporate management perspective. Using historical performance data as training data, this study focused on real-time box recommendations applicable to packaging areas during fulfillment center shipping. Four types of data, such as product information, order information, packaging information, and delivery information, were applied to the machine learning model through pre-processing and feature-engineering processes. As an input vector, three characteristics were used as product specification information: width, length, and height, the characteristics of the input vector were extracted through a feature engineering process that converts product information from real numbers to an integer system for each section. As a result of comparing the performance of each model, it was confirmed that when the Gradient Boosting model was applied, the prediction was performed with the highest accuracy at 95.2% when the product specification information was converted into integers in 21 sections. This study proposes a machine learning model as a way to reduce the increase in costs and inefficiency of box packaging time caused by incorrect box selection in the fulfillment center, and also proposes a feature engineering method to effectively extract the characteristics of product specification information.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2639-2644
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• 2013

The renewal cycle, which newly decorates stores, has been shortened, as the marketing competition between telecommunication companies has been extended to the stores, due to the rapid increase of mobile phone users and fast replacement cycle of products. The store renewal made by major telecommunication companies, including signboard, has been pushed in order for telecommunication companies to give strong impression about their own brand identity to consumers. Consumers want stores not only to sell cheap and high quality products but also to provide customer experience, by which customers can feel store, product and service and accept them. Especially, since the competition between telecommunication companies is getting tough, it is the current trend that the number of stores is increasing much, and telecommunication companies are recently renewing their stores, with the concept of SI(Store Identity), which changes store image into the incorporated image including interior and exterior, rather than just replacing CI(Corporate Identity), when they renew stores. It can be said that SI(Store Identity) is an important factor, by which companies consistently design visual factors such as interior and sign, and then apply them to the interior and exterior of the stores, and thereby give good store image to consumers, and ultimately have great effect on the increase of sales volume. This kind of activity can be image-controlled by companies' Identity Management, and it can be a very important factor in terms of marketing. In this study, it has an objective to compare and analyze SI of domestic telecommunication companies and foreign telecommunication companies, and then suggest effective SI direction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.287-297
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• 2019

Responding to the rapid delivery demands and variety of small-volume products through human resource-dependent logistics operations in online markets is difficult. Logistics robots in fulfillment centers are expected to increase due to difficulties in hiring workers and rising labor costs. Amazon operates more than 100,000 robots in its Fulfillment centers. Alibaba, DHL, and UPS are also introducing robot technology to improve the logistics efficiency. Logistics robots are being used actively in the fierce online market competition of the global distribution industry. On the other hand, Korea is relatively sluggish. To revitalize the introduction of logistics robots in Korea, it is necessary to examine the factors that influence acceptance. The description of acceptability was based on an expanded technology acceptance model that has been verified through various studies. Studies have shown that both the ease and usefulness of purchasing have significant effects, and that ease has the greatest effect. The more experience involved, the more innovative, the more positive. The usefulness was shown to be positive as the perceived risks are low, price efficiency is good, and social impact is greater. This study provides theoretical and practical implications for logistics robot development and marketing.

• Information Systems Review
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• v.23 no.4
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• pp.45-67
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• 2021

As the transaction volume of the C2C second-hand market is growing, the number of frauds, which intend to earn unfair gains by sending products different from specified ones or not sending them to buyers, is also increasing. This study explores the model that can identify frauds in the online C2C second-hand market by examining the postings for transactions. For this goal, this study collected 145,536 field data from actual C2C second-hand market. Then, the model is built with the characteristics from postings such as the topic and the linguistic characteristics of the product description, and the characteristics of products, postings, sellers, and transactions. The constructed model is then trained by the machine learning algorithm XGBoost. The final analysis results show that fraudulent postings have less information, which is also less specific, fewer nouns and images, a higher ratio of the number and white space, and a shorter length than genuine postings do. Also, while the genuine postings are focused on the product information for nouns, delivery information for verbs, and actions for adjectives, the fraudulent postings did not show those characteristics. This study shows that the various features can be extracted from postings written in C2C second-hand transactions and be used to construct an effective model for frauds. The proposed model can be also considered and applied for the other C2C platforms. Overall, the model proposed in this study can be expected to have positive effects on suppressing and preventing fraudulent behavior in online C2C markets.

• Journal of Climate Change Research
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• v.2 no.2
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• pp.115-131
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• 2011

Out of all the possible actions that can be taken to respond to greenhouse gas reduction, including development of greenhouse gas reduction technology, infrastructure, actions to improve energy saving and efficiency, and offset with carbon emission reductions (CERs), this study shall focus on the investment on CERs. This study will take a look at risks involved with investing in CERs such as UN registration refusal risk and CERs price fluctuation, and will design risk management model which shall be verified. The goal of this paper is to provide optimized CERs investment strategies for different types of investors, such as general trading companies seeking for investment opportunities and financial companies with plans for green products development and investment by preparation for carbon market. It is expected that the global competitiveness of domestic financial companies shall be improved by taking actions on carbon market instead of previous passive response to climate change and that Korea, the number two Carbon Emissions supplier and number one derivatives market in terms of volume, shall be able to lead the worldwide carbon market.