• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.6
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• pp.1523-1537
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• 2018

The AI speaker is a simple operation that provides users with useful functions such as music playback, online search, and so the AI speaker market is growing at a very fast pace. However, AI speakers always wait for the user's voice, which can cause serious problems such as eavesdropping and personal information exposure if exposed to security threats. Therefore, in order to provide overall improved security of all AI speakers, it is necessary to identify potential security threats and analyze them systematically. In this paper, security threat modeling is performed by selecting four products with high market share. Data Flow Diagram, STRIDE and LINDDUN Threat modeling was used to derive a systematic and objective checklist for vulnerability checks. Finally, we proposed a method to improve the security of AI speaker by comparing the vulnerability analysis results and the vulnerability of each product.

• Journal of Positioning, Navigation, and Timing
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• v.8 no.2
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• pp.79-85
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• 2019

The mission tasks of polar exploration utilizing unmanned systems such as glacier monitoring, ecosystem research, and inland exploration have been expanded. To facilitate unmanned exploration mission tasks, precise and robust navigation systems are required. However, limitations on the utilization of satellite navigation system are present due to satellite orbital characteristics at the polar region located in a high latitude. The orbital inclination of global positioning system (GPS), which was developed to be utilized in mid-latitude sites, was designed at $55^{\circ}$. This means that as the user is located in higher latitudes, the satellite visibility and vertical precision become worse. In addition, the use of satellite-based wide-area augmentation system (SBAS) is also limited in higher latitude regions than the maximum latitude of signal reception by stationary satellites, which is $70^{\circ}$. This study proposes a local-area augmentation system that additionally utilizes Global Navigation Satellite System (GLONASS) considering satellite navigation system environment in Polar Regions. The orbital inclination of GLONASS is $64.8^{\circ}$, which is suitable in order to ensure satellite visibility in high-latitude regions. In contrast, GLONASS has different system operation elements such as configuration elements of navigation message and update cycle and has a statistically different signal error level around 4 m, which is larger than that of GPS. Thus, such system characteristics must be taken into consideration to ensure data integrity and monitor GLONASS signal fault. This study took GLONASS system characteristics and performance into consideration to improve previously developed fault detection algorithm in the local-area augmentation system based on GPS. In addition, real GNSS observation data were acquired from the receivers installed at the Antarctic King Sejong Station to analyze positioning accuracy and calculate test statistics of the fault monitors. Finally, this study analyzed the satellite visibility of GPS/GLONASS-based local-area augmentation system in Polar Regions and conducted performance evaluations through simulations.

• Journal of Information Science Theory and Practice
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• v.9 no.2
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• pp.1-17
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• 2021

Pseudo relevance feedback (PRF) is a powerful query expansion (QE) technique that prepares queries using the top k pseudorelevant documents and choosing expansion elements. Traditional PRF frameworks have robustly handled vocabulary mismatch corresponding to user queries and pertinent documents; nevertheless, expansion elements are chosen, disregarding similarity to the original query's elements. Word embedding (WE) schemes comprise techniques of significant interest concerning QE, that falls within the information retrieval domain. Deep averaging networks (DANs) defines a framework relying on average word presence passed through multiple linear layers. The complete query is understandably represented using the average vector comprising the query terms. The vector may be employed for determining expansion elements pertinent to the entire query. In this study, we suggest a DANs-based technique that augments PRF frameworks by integrating WE similarities to facilitate Arabic information retrieval. The technique is based on the fundamental that the top pseudo-relevant document set is assessed to determine candidate element distribution and select expansion terms appropriately, considering their similarity to the average vector representing the initial query elements. The Word2Vec model is selected for executing the experiments on a standard Arabic TREC 2001/2002 set. The majority of the evaluations indicate that the PRF implementation in the present study offers a significant performance improvement compared to that of the baseline PRF frameworks.

• Journal of Digital Convergence
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• v.20 no.5
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• pp.323-329
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• 2022

In this study, users of the display system designed for the conference hall were evaluated as an example of a temporary space marking system for vaccination at a COVID-19 vaccination center in Chuncheon, Gangwon Province.Unlike ordinary space, temporary space display systems organize space on a limited schedule, so it is necessary to properly place and communicate information about space and processes in the display design to users. Therefore, a paper description manual, a wall display panel, and a floor path tape were provided and deployed to users of the inoculation session. The results of user evaluations show that for specific users over 60 years of age, a file (information display system) that conveys the overall information about the space and process is effective for vaccination. This result is expected to serve as a reference to how and how the display system will be installed in a temporary space in the future.

• Design Convergence Study
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• v.15 no.2
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• pp.223-236
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• 2016

The infrastructure of public transportation of Seoul which has been developed in parallel with the progress of modernization receives successful performance evaluation at home and abroad, currently representing the highest transport distribution ratio. In spite of this fact, the public transportation of Seoul, which has entered into advanced phase of services, still leaves much to be desired, in particular, the mobility considering the transportation vulnerable is not well assured. It is time to provide proper supports for the efficient mobility of public transportation in accordance with the social changes present in the aging and multicultural society. This study inquired about the current status of public transportation and that of its users. In addition, the main inquiry target was oriented to the elderly and foreigners for observation and investigation, as well as for the analysis of their behavior. Furthermore, through in-depth interviews, inconvenient factors have been found according to public transportation means and its usage phase, by carrying out detailed evaluations of public transportation services. Based on this, the enhancement elements were defined and the corresponding concept was designed through a series of idea workshops, and this study intended to contribute to improving future public transportation services by proposing the improvement scheme applicable to the upcoming public transportation.

• The Journal of the Korea Contents Association
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• v.22 no.8
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• pp.33-43
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• 2022

Labeled graphs are used to represent entities, their relationships, and their structures in real data such as knowledge graphs and protein interactions. With the rapid development of IT and the explosive increase in data, there has been a need for a subgraph matching technology to provide information that the user is interested in. In this paper, we propose an approximate Top-k labeled subgraph matching scheme that considers the semantic similarity of labels and the difference in graph structure. The proposed scheme utilizes a learning model using FastText in order to consider the semantic similarity of a label. In addition, the label similarity graph(LSG) is used for approximate subgraph matching by calculating similarity values between labels in advance. Through the LSG, we can resolve the limitations of the existing schemes that subgraph expansion is possible only if the labels match exactly. It supports structural similarity for a query graph by performing searches up to 2-hop. Based on the similarity value, we provide k subgraph matching results. We conduct various performance evaluations in order to show the superiority of the proposed scheme.

• Journal of Information Technology Services
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• v.22 no.5
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• pp.109-124
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• 2023

This study aims to apply the concept of regulatory stringency to the regulatory sandbox with a fresh perspective. The regulatory sandbox is a system that gives opportunities under certain conditions to new technologies or businesses that have not been launched due to inadequacy or insufficiency in legal systems. Previous research on regulatory sandboxes has mainly focused on discussions about their impact on specific technologies or business domains. This study attention to the results according to the evaluations. Among them, whether special cases for demonstration can evolve into official permission has garnered significant attention. For this study, among the cases that passed the regulatory sandbox evaluation from February, 2019, to December, 2022, 162 cases in the field of ICT convergence were selected. The evaluation results were classified into three groups 'positive interpretation (Fast Track)', 'temporary permission', and 'special case for demonstration.' Each case was assigned to one of the three groups. Through the comparative analysis, the common characteristics and differences were summarized. Then, this study explored improvement measures to pass a less restrictive regulatory sandbox. The analysis of the cases revealed that the differences in each evaluation result were attributed to variations in the technological characteristics and user protection features. Considering these differences, as well as the higher weight and importance of the preparation stage for sandbox application, this study suggested a three-step approach to prepare for temporary permission and positive interpretation rather than special case for demonstration. In addition, this thesis discussed the policy limitations of the regulatory sandbox mechanism in South Korea and the limitations of the current study. Hopefully, the results of this study would be beneficial to individuals and companies, particularly venture companies and startups seeking to develop new technologies or businesses and utilize regulatory sandboxes.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.5
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• pp.927-934
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• 2023

With the recent growth of the companion animal market, various social issues related to companion animals have also come to the forefront. Notable problems include incidents of dog bites, the challenge of managing abandoned companion animals, euthanasia, animal abuse, and more. As potential solutions, a variety of training programs such as companion animal-focused broadcasts and educational apps are being offered. However, these options might not be very effective for novice caretakers who are uncertain about what to prioritize in training. While training apps that are relatively easy to access have been widely distributed, apps that allow users to directly engage in training and learn through hands-on experience are still insufficient. In this paper, we propose a more efficient AR-based mobile app for companion animal training, utilizing the Unity engine. The results of usability evaluations indicated increased user engagement due to the inclusion of elements that were previously absent. Moreover, training immersion was enhanced, leading to improved learning outcomes. With further development and subsequent verification and production, we anticipate that this app could become an effective training tool for novice caretakers planning to adopt companion animals, as well as for experienced caretakers.

• Journal of the Korea Society of Computer and Information
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• v.29 no.5
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• pp.143-153
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• 2024

This study aims to analyze both the current utilization of e-learning in the scuba diving education sector and the possible improvements by using Delphi analysis. The study administered three rounds of Delphi surveys with 25 specialists, including business executives and educational leaders from scuba diving centers and resorts affiliated with organizations that conduct scuba diving education through e-learning. The comparative analysis of the state of e-learning utilization and factors for improvement revealed significant insights. In terms of expected benefits, the analysis highlighted an increase in user convenience, temporal flexibility in learning activities, and easy access to products. However, it identified major issues such as the simplistic mandatory exams, inadequate professional depth in the feedback provided, and a lack of bidirectional communication between learners and instructors. Recommendations for improvements included enhancing communication through various online communities, conducting mandatory exams offline, and developing a variety of content. Conducting regular program quality evaluations, integrating with various diving communities, and assigning dedicated tutors were deemed crucial factors for future development.

• Korean Journal of Clinical Pharmacy
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• v.13 no.2
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• pp.82-90
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• 2003

Dopamine is an effective pressor for the treatment of shock and hypotension when patients do not respond to plasma volume expansion. Two dopamine intravenous delivery systems are currently available in Korea. The objective of this study was to compare dopamine premixed with prefilled system in terms of supply costs (preparation costs + personnel time), contamination rates and convenience. Time-and-motion studies were conducted to determine the time and costs associated with preparation and administration of the two systems. They were analyzed and compared by Mann-Whitney test. To evaluate the contaminaton rates of the two systems, both systems were prepared in an open environment similar to that of practical situations. Premixed and compounded solutions were then filtered by $0.22{\mu}m$ membrane filters, which were cultured at $37^{\circ}C$ for 10 days and their contents were visually checked for bacterial contamination. The convenience of the two systems was compared by itemized user assessments on preparation, dose calculation, admixture, administration and disposal of waste matters. They were analyzed by Wilcoxon's signed rank test and 100 part percentage. It was found that the preparation costs $(mean{\pm}SD)$ for premixed and prefilled systems were $271.70\pm293.55\;Won$ (Korean currency) and $1521.04\pm510.63\;Won$, respectively. The preparation time $(mean{\pm}SD)$ for premixed system was $68.10\pm35.69\;sec.$ while at for prefilled system was $154.03\pm50.06\;sec.$ (n=59 each, p<0.001). No bacterium was observed in the samples of both systems (n=20, each). User assessments indicated that the premixed system was more convenient than the prefilled system except for the item of dose calculation (n=24, p<0.001). Subjective evaluations have proven that the use of the dopamine premixed system resulted in increased efficiency of intravenous preparation by allowing personnel to devote more time to other labor-intensive duties and lower total medical costs.