• The Journal of Bigdata
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• 제7권2호
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• pp.235-244
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• 2022

The rental history data of public bicycles in Seoul were analyzed to examine how pandemic phenomena such as COVID-19 caused changes in people's micro mobility. Data for 2019 and 2021 were compared and analyzed by dividing them before and after COVID-19. Data were collected from public data portal sites, and data marts were created for in-depth analysis. In order to compare the changes in the two periods, the riding direction type dimension and the rental station type dimension were added, and the derived variables (rotation rate per unit, riding speed) were newly created. There is no significant difference in the average rental time before and after COVID-19, but the average rental distance and average usage speed decreased. Even in the mobility of Ttareungi, you can see the slow rhythm of daily life. On weekdays, the usage rate was the highest during commuting hours even before COVID-19, but it increased rapidly after COVID-19. It can be interpreted that people who are concerned about infection prefer Ttareungi to village buses as a means of micro-mobility. The results of data mart-based visualization and analysis proposed in this study will be able to provide insight into public bicycle operation and policy development. In future studies, it is necessary to combine SNS data such as Twitter and Instagram with public bicycle rental history data. It is expected that the value of related research can be improved by examining the behavior of bike users in various places.

• Journal of Korea Entertainment Industry Association
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• 제13권5호
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• pp.119-126
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• 2019

Watching movies is common on a big screen like a theater or on a big-screen TV. nowadays, small platform such as mobile devices is increasing rapidly for watch a movie. These changes are deeply related to the advent of Internet-based video streaming services such as OTT. OTT's development has provided in free video viewing system without using the set-top box is free from the limitations of time and space. Leading the market is Netflix[1], which started its business with Internet-based DVD rental service. Netflix, which is growing in tandem with the mobile market, had 193.26[2] million members as of the end of 2018. Other OTT participating companies include content-based Pooq, TVing, platform-based Olleh TV Mobile, Oksusu and LTE video portal. The size of such new growth projects has grown gradually, with 25.4 percent of all smartphone users currently watching video content with small mobile devices. Therefore, de-largeization, it is thought that visual language is needed for viewing small mobile devices that are capable of OTT services. To this end, this paper will identify the problem in viewing popular video content with small mobile devices and Survey and study its impact on viewers using the questionnaire.

• Economic and Environmental Geology
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• 제56권5호
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• pp.533-545
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• 2023

In this study, an investigation was conducted on the features, events, and processes (FEP) that could impact the long-term safety of the natural barriers constituting high-level radioactive waste geological repositories. The FEP list was developed utilizing the IFEP list 3.0 provided by the Nuclear Energy Agency (NEA) as foundational data, supplemented by geological investigations and research findings from leading countries in this field. A total of 49 FEPs related to the performance of the natural barrier were identified. For each FEP, detailed definitions, classifications, impacts on long-term safety, significance in domestic conditions, and feasibility of quantification were provided. Moreover, based on the compiled FEP list, three scenarios that could affect the long-term safety of the disposal facility were developed. Geological factors affecting the performance of the natural barrier in each scenario were selected and their relationships were visualized. The constructed FEP list and the visualization of interrelated factors in various scenarios are anticipated to provide essential information for selecting and organizing factors that must be considered in the development of mathematical models for quantitatively evaluating the long-term safety of deep geological repositories. In addition, these findings could be effectively utilized in establishing criteria related to the key performance of natural barriers for the confirmation of repository sites.

• Information Systems Review
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• 제25권4호
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• pp.27-45
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• 2023

The importance of information security has grown alongside the development of information and communication technology. However, companies struggle to select suitable countermeasures within their limited budgets. Sönmez and Kılıç (2021) proposed a model using AHP and mixed integer programming to determine the optimal investment combination for mitigating information security breaches. However, their model had limitations: 1) a lack of objective measurement for countermeasure efficacy against security threats, 2) unrealistic scenarios where risk reduction surpassed pre-investment levels, and 3) cost duplication when using a single countermeasure for multiple threats. This paper enhances the model by objectively quantifying countermeasure efficacy using the beta probability distribution. It also resolves unrealistic scenarios and the issue of duplicating investments for a single countermeasure. An empirical analysis was conducted on domestic SMEs to determine investment budgets and risk levels. The improved model outperformed Sönmez and Kılıç's (2021) optimization model. By employing the proposed effectiveness measurement approach, difficulty to evaluate countermeasures can be quantified. Utilizing the improved optimization model allows for deriving an optimal investment portfolio for each countermeasure within a fixed budget, considering information security costs, quantities, and effectiveness. This aids in securing the information security budget and effectively addressing information security threats.

• Imaging Science in Dentistry
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• 제54권2호
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• pp.129-137
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• 2024

Purpose: Patients with head and neck cancer (HNC) who undergo dental procedures during radiotherapy (RT) face an increased risk of developing osteoradionecrosis (ORN). Accordingly, new tools must be developed to extract critical information regarding the dose delivered to the teeth and mandible. This article proposes a novel approach for visualizing 3-dimensional planned dose distributions on panoramic reconstruction computed tomography (pCT) images. Materials and Methods: Four patients with HNC who underwent volumetric modulated arc therapy were included. One patient experienced ORN and required the extraction of teeth after RT. In the study approach, the dental arch curve (DAC) was defined using an open-source platform. Subsequently, pCT images and dose distributions were generated based on the new coordinate system. All teeth and mandibles were delineated on both the original CT and pCT images. To evaluate the consistency of dose metrics, the Mann-Whitney U test and Student t-test were employed. Results: A total of 61 teeth and 4 mandibles were evaluated. The correlation coefficient between the 2 methods was 0.999, and no statistically significant difference was observed (P>0.05). This method facilitated a straightforward and intuitive understanding of the delivered dose. In 1 patient, ORN corresponded to the region of the root and the gum receiving a high dosage (approximately 70 Gy). Conclusion: The proposed method particularly benefits dentists involved in the management of patients with HNC. It enables the visualization of a 3-dimensional dose distribution in the teeth and mandible on pCT, enhancing the understanding of the dose delivered during RT.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• 제41권3호
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• pp.27-46
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• 2023

This study examines the possibility of applying Other Effective Area-based Conservation Measures (OECMs) to natural heritage sites that are not designated as protected areas for the National Biodiversity Strategy and Action Plan (NBSAP). Firstly, the study investigated the ecological and cultural characteristics associated with a natural heritage site, specifically the natural monument known as Dangsanmok, and synthesized the collected information to assess its conservation value. Subsequently, the study examined the possibility of designating Dangsanmok as an OECM that reflects local communities through the criteria of the IUCN's individual assessment tools. The research findings indicate that Dangsanmok and the associated Dangsanje system are positively evaluated as potential OECMs. Additionally, initiatives such as the "Dangsan Tree Grandfather Program" and the "National Heritage Folk Event Grant Program," implemented by the Cultural Heritage Administration, are seen to have a positive impact on engaging local communities voluntarily. Consequently, based on these results, it is expected that natural heritage sites like Dangsanmok, serving as national indicators, will contribute to the 2030 goals for biodiversity conservation and the 2050 goals for harmonious coexistence with nature as part of NBSAPs.

• Journal of the Korean Association of Geographic Information Studies
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• 제27권1호
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• pp.41-51
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• 2024

If an underground accident occurs, the cause must be quickly identified and human and material damage reduced. The Underground Accident Investigation Committee is responsible for identifying the causes of accidents and preparing response plans to prevent similar accidents from occurring in the future. The law stipulates that the Underground Accident Investigation Committee can operate from a minimum of 6 months to a maximum of 9 months after an accident occurs. However, the operation schedule of the Underground Accident Investigation Committee seems difficult to cite the accident investigation report to the construction project currently in progress at the same time project. In this study, the Underground Accident Investigation Committee seeks to establish a strategy for developing technology that can shorten data collection and analysis, which previously took 3 months, to less than 1 month. As a result of the research, five areas of technology development identified, ground data collection and transmission technology, ground safety data generation technology, digital twin-based underground safety analysis and visualization technology, digital twin-based geo-ambulance construction and operation technology, and digital twin-based geo-ambulance standardization and legal system. research was able to be conducted. If the proposed technology is developed, it is expected to contribute to reducing accident scenes through faster decision making than before.

• The Journal of the Convergence on Culture Technology
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• 제10권3호
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• pp.891-899
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• 2024

The Fourth Industrial Revolution is centered on a personalized demand fulfillment economy and is all about transformation and flexible processing that can deliver what customers want in real time across space and time. This paper implements the construction and operation of a packaging platform that can instantly procure the required packaging products based on real-time orders and evaluates its performance. The components of customer satisfaction are flexible and dependent on the situation which requires efficient management of enterprise operational processes based on an e-SCM platform. An OMS optimized for these conditions plays an important role in maximizing and differentiating the efficiency of a company's operations and improving its cost advantage. OMS is a system of mass customization that provides efficient MOT(Moment of Truth) logistics services to meet the eco-friendly issues of many individual customers and achieve optimized logistics operation goals to enhance repurchase intentions and sustainable business. OMS precisely analyzes the collected data to support information and decision-making related to efficiency, productivity, cost and provide accurate reports. It uses data visualization tools to express data visually and suggests directions for improvement of the operational process through statistics and prediction analysis.

• Radiation Oncology Journal
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• 제21권1호
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• pp.100-106
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• 2003

Purpose : To develop a patients' setup verification tool (PSVT) to verify the alignment of the machine and the target isocenters, and the reproduclbility of patients' setup for three dimensional conformal radiotherapy (3DCRT) and intensity modulated radiotherapy (IMRT). The utilization of this system is evaluated through phantom and patient case studies. Materials and methods : We developed and clinically tested a new method for patients' setup verification, using digitally reconstructed radiography (DRR), simulation, porial and digital images. The PSVT system was networked to a Pentium PC for the transmission of the acquired images to the PC for analysis. To verify the alignment of the machine and target isocenters, orthogonal pairs of simulation images were used as verification images. Errors in the isocenter alignment were measured by comparing the verification images with DRR of CT Images. Orthogonal films were taken of all the patients once a week. These verification films were compared with the DRR were used for the treatment setup. By performing this procedure every treatment, using humanoid phantom and patient cases, the errors of localization can be analyzed, with adjustments made from the translation. The reproducibility of the patients' setup was verified using portal and digital images. Results : The PSVT system was developed to verify the alignment of the machine and the target isocenters, and the reproducibility of the patients' setup for 3DCRT and IMRT. The results show that the localization errors are 0.8$\pm$0.2 mm (AP) and 1.0$\pm$0.3 mm (Lateral) in the cases relating to the brain and 1.1$\pm$0.5 mm (AP) and 1.0$\pm$0.6 mm (Lateral) in the cases relating to the pelvis. The reproducibility of the patients' setup was verified by visualization, using real-time image acquisition, leading to the practical utilization of our software Conclusions : A PSVT system was developed for the verification of the alignment between machine and the target isocenters, and the reproduclbility of the patients' setup in 3DCRT and IMRT. With adjustment of the completed GUI-based algorithm, and a good quality DRR image, our software may be used for clinical applications.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• 제20권6호
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• pp.427-446
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• 2008

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2006 has been accomplished. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro heat exchanger and siphon cooling device using nano-fluid. Traditional CFD and flow visualization methods were still popular and widely used in research and development. Studies about diffusers and compressors were performed in fluid machinery. Characteristics of flow and heat transfer and piping optimization were studied in piping systems. (2) The papers on heat transfer have been categorized into heat transfer characteristics, heat exchangers, heat pipes, and two-phase heat transfer. The topics on heat transfer characteristics in general include thermal transport in a cryo-chamber, a LCD panel, a dryer, and heat generating electronics. Heat exchangers investigated include pin-tube type, plate type, ventilation air-to-air type, and heat transfer enhancing tubes. The research on a reversible loop heat pipe, the influence of NCG charging mass on heat transport capacity, and the chilling start-up characteristics in a heat pipe were reported. In two-phase heat transfer area, the studies on frost growth, ice slurry formation and liquid spray cooling were presented. The studies on the boiling of R-290 and the application of carbon nanotubes to enhance boiling were noticeable in this research area. (3) Many studies on refrigeration and air conditioning systems were presented on the practical issues of the performance and reliability enhancement. The air conditioning system with multi indoor units caught attention in several research works. The issues on the refrigerant charge and the control algorithm were treated. The systems with alternative refrigerants were also studied. Carbon dioxide, hydrocarbons and their mixtures were considered and the heat transfer correlations were proposed. (4) Due to high oil prices, energy consumption have been attentioned in mechanical building systems. Research works have been reviewed in this field by grouping into the research on heat and cold sources, air conditioning and cleaning research, ventilation and fire research including tunnel ventilation, and piping system research. The papers involve the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies on indoor air quality took a great portion in the field of building environments. Various other subjects such as indoor thermal comfort were also investigated through computer simulation, case study, and field experiment. Studies on energy include not only optimization study and economic analysis of building equipments but also usability of renewable energy in geothermal and solar systems.