• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1033-1038
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• 2005

As a global effort to conservate the environment, life cycle assessment(LCA) which considers the environmental impact through the life cycle of a product, from acquiring of resources to scrapping, has been actively applied. The LCA is a tool to calculate quantitatively the environmental impacts caused by products or services through their life cycles. The list of numerous data should be analyzed, stored and conducted in order to assess the environmental impacts. Therefore, it is necessary to develop a software for LCA, which can perform the interpretation as well as the environment impact assessment to execute the analysis of such a large number of data effectively. At this time, for the existing some kinds of general LCA softwares, the information about all of input and output should be fed directly and the conclusion is deduced by linking to the database from the public authorized organizations. That makes it possible to evaluate the environmental grades accurately, but it is too slow and difficult for general users to operate and applied it into an electric motor unit(EMU). Therefore, in this research, the basic model was designed, which is based on construction of database structure of the software and organization of architecture, to develop an advanced software for EMU according to user and purpose of it by benchmarking of domestic and international softwares. The result of this study would be applied to develop the LCA software in the future.

• Computers and Concrete
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• v.6 no.4
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• pp.281-303
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• 2009

The lack of safety of bridge deck structures causes frequent repair and strengthening of such structures. The repair induces great loss of economy, not only due to direct cost by repair, but also due to stopping the public use of such structures during repair. The major reason for this frequent repair is mainly due to the lack of realistic and accurate assessment system for the bridge decks. The purpose of the present research was to develop a realistic expert system, called Bridge Slab-Expert which can evaluate reasonably the condition as well as the service life of concrete bridge decks, based on the deterioration models that are derived from both the structural and environmental effects. The diagnosis assessment of deck slabs due to structural and environmental effects are developed based on the cracking in concrete, surface distress and structural distress. Fuzzy logic is utilized to handle uncertainties and imprecision involved. Finally, Bridge Slab-Expert is developed for prediction of safety and remaining service life based on the chloride ions penetration and fick's second law. Proposed expert system is based on user-friendly GUI environment. The developed expert system will allow the correct diagnosis of concrete decks, realistic prediction of service life, the determination of confidence level, the description of condition and the proposed action for repair.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.121-131
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• 2022

We look at the initial stage of Meta (previous Facebook)'s new metaverse platform and investigate its platform design in pre-launch and ignition life stage. From the Rocket Model (RM)'s theoretical logic, the results reveal that Meta firstly focuses on investing in key content developers by acquiring virtual reality (VR), video, music content firms and offering production support platform of the augmented reality (AR) content, 'Spark AR' last three years (2019~2021) for attracting high-potential developers and users. In terms of three matching criteria, Meta develops an Artificial Intelligence (AI) powered translation software, partners with Microsoft (MS) for cloud computing and AI, and develops an AI platform for realistic avatar, MyoSuite. In 'connect' function, Meta curates the game concept submitted by game developers, welcomes other game and SNS based metaverse apps, and expands Horizon Worlds (HW) on VR devices to PCs and mobile devices. In 'transact' function, Meta offers 'HW Creator Funding' program for metaverse, launches the first commercialized Meta Avatar Store on Meta's conventional SNS and Messaging apps by inviting all fashion creators to design and sell clothing in this store. Mata also launches an initial test of non-fungible token (NFT) display on Instagram and expands it to Facebook in the US. Lastly, regarding optimization, especially in the face of recent data privacy issues that have adversely affected corporate key performance indicators (KPIs), Meta assures not to collect any new data and to make its privacy policy easier to understand and update its terms of service more user friendly.

• International Journal of Highway Engineering
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• v.18 no.3
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• pp.47-57
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• 2016

PURPOSES : This study aims to examine the differences between the existing traffic demand forecasting method and the traffic demand forecasting method considering future regional development plans and new road construction and expansion plans using a four-step traffic demand forecast for a more objective and sophisticated national highway maintenance. This study ultimately aims to present future pavement deterioration and budget forecasting planning based on the examination. METHODS : This study used the latest data offered by the Korea Transport Data Base (KTDB) as the basic data for demand forecast. The analysis scope was set using the Daejeon Metropolitan City's O/D and network data. This study used a traffic demand program called TransCad, and performed a traffic assignment by vehicle type through the application of a user equilibrium-based multi-class assignment technique. This study forecasted future traffic demand by verifying whether or not a realistic traffic pattern was expressed similarly by undertaking a calibration process. This study performed a life cycle cost analysis based on traffic using the forecasted future demand or existing past pattern, or by assuming the constant traffic demand. The maintenance criteria were decided according to equivalent single axle loads (ESAL). The maintenance period in the concerned section was calculated in this study. This study also computed the maintenance costs using a construction method by applying the maintenance criteria considering the ESAL. The road user costs were calculated by using the user cost calculation logic applied to the Korean Pavement Management System, which is the existing study outcome. RESULTS : This study ascertained that the increase and decrease of traffic occurred in the concerned section according to the future development plans. Furthermore, there were differences from demand forecasting that did not consider the development plans. Realistic and accurate demand forecasting supported an optimized decision making that efficiently assigns maintenance costs, and can be used as very important basic information for maintenance decision making. CONCLUSIONS : Therefore, decision making for a more efficient and sophisticated road management than the method assuming future traffic can be expected to be the same as the existing pattern or steady traffic demand. The reflection of a reliable forecasting of the future traffic demand to life cycle cost analysis (LCCA) can be a very vital factor because many studies are generally performed without considering the future traffic demand or with an analysis through setting a scenario upon LCCA within a pavement management system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.5
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• pp.558-563
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• 2014

In order to reduce the risk of deaths from hypothermia at sea, this paper suggests the performance criteria of life rafts for small fishing vessels less than 20 m in length. In our country, the life rafts are not used and have no performance criteria. This research compared the performance criteria of the domestic, foreign, international standards, and the performance comparison between foreign life rafts and the user-friendly valise prototype(2 & 4 persons) which is developed by this study. As a result, it is considered to be appropriate that ISO 9650-1 can be applied to the life rafts for offshore fishing vessels while a milder criteria can be applied to the life rafts for coastal fishing vessels.

• Journal of Families and Better Life
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• v.25 no.5
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• pp.31-46
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• 2007

The purpose of this study was to determine the differences in internet use motivations and problem behaviors among vocational high school students according to internet addiction and family system type. Five hundred vocational high school students from Daegu took part in the survey. The questionnaire survey consisted of an internet addiction self-assessment scale, a family system type scale, an internet use motivation scale, and a problem behavior scale. The data was analysed using MANOVA and Cronbach a, and the $Scheff\acute{e}$ test was used for post-hoc analysis. The major findings of this study were as follows: First, the study found significant differences in adolescent internet use motivation according to internet addiction. Adolescents in the high dangerous user group showed higher communicative, experiential, and addictive motivations than adolescents in potentially dangerous and normal user groups. Also, there were no significant differences in informative motivation according to internet addiction. Regardless of internet addiction, adolescents tend to use the internet to search for information and to solve problems. Second, there were significant differences in adolescents' problem behaviors according to internet addiction. More specifically, adolescents who were in the high dangerous user group displayed more problem behaviors toward their body, family, school, and society than adolescents in the potentially dangerous and the normal user groups. Third, an adolescent's family system type significantly influenced his/her internet use motivation. Adolescents from an extreme family showed higher communicative and addictive motivations than adolescents from middle and balanced families. Fourth, there were significant differences in the problem behaviors of adolescents according to family system types. Adolescents from an extreme family showed more problem behaviors toward their body, family, school, and society than adolescents from middle and balanced families.

• The Journal of the Korea Contents Association
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• v.14 no.4
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• pp.19-28
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• 2014

Recent advancements in the IT industry have made daily life more convenient than ever before. In particular, studies have focused on the position detection of individuals using the GPS in smartphones, and this application has been utilized actively in emergency rescue organizations. However, existing methods send the location information of a user to a predetermined guardian set by the user or to a control center when the user enters into or deviates from a predetermined space. Such spaces are created by an arbitrary radius, thereby making it difficult to set a detailed area by using an existing radius-area creation method in an unstructured space and path with a specific road, such as for trekking, amusement parks, or mountaineering. This study proposes a novel method for setting up an area by connecting multiple radii to improve the existing radius-area creation method in order to easily set a detailed area in smart devices or on the Internet. In addition, an optimization method for resource use is proposed by comparing the operation results in which a user's location is detected by using the proposed location-based area setup method and deviation detection.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.4 s.304
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• pp.25-32
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• 2005

The spread of mobile devices, PDAs and sensors has enabled the construction of ubiquitous computing environments, transforming regular physical spaces into 'Smart space' augmented with intelligence and enhanced with services. However, the deployment of this computing paradigm in real-life is disturbed by poor security, particularly, the lack of proper authentication and authorization techniques. Also, it is very important not only to find security measures but also to preserve user privacy in ubiquitous computing environments. In this Paper, we propose efficient user authentication and authorization model with anonymity for the privacy-preserving for ubiquitous computing environments. Our model is suitable for distributed environments with the computational constrained devices by using MAC-based anonymous certificate and security association token instead of using Public key encryption technique. And our Proposed Protocol is better than Kerberos system in sense of cryptographic computation processing.

• Journal of Digital Convergence
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• v.10 no.3
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• pp.191-196
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• 2012

The importance of hi-tech communications technology including mobile or ubiquitous system and the related business field is currently expanding. In terms of wellness for enhancing quality of individual life, ICT technology became a requirement, not an option. The first purpose of this study is to identify factors that influence user's perceived usefulness & perceived ease of use related to the acceptance of TAM focused on ubiquitous fitness service through multiple regression analysis, thereby discovering important factors influencing consumer behavior. In conjunction with the result, the second purpose of this study has also its implication on the u-Healthcare system development using QFD. That is, this research is to propose the possibility of combining the external variables of TAM to u-Healthcare system service characteristics with user requirement reflected by using QFD method. Based on these results, the suitable system may be constructed and developed.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.67-72
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• 2020

The fifth generation (5G) mobile communication has an impact on the human life over the whole world, nowadays, through the artificial intelligence (AI) and the internet of things (IoT). The low latency of the 5G new radio (NR) access is implemented by the state-of-the art technologies, such as non-orthogonal multiple access (NOMA). This paper investigates a practical issue that in NOMA, for the practical channel models, such as fading channel environments, the successive interference cancellation (SIC) should be performed on the stronger channel users with low power allocation. Only if the SIC is performed on the user with the stronger channel gain, NOMA performs better than orthogonal multiple access (OMA). Otherwise, NOMA performs worse than OMA. Such the superiority requirement can be easily implemented for the channel being static or slow varying, compared to the block interval time. However, most mobile channels experience fading. And symbol by symbol channel estimations and in turn each symbol time, selections of the SIC-performing user look infeasible in the practical environments. Then practically the block of symbols uses the single channel estimation, which is obtained by the training sequence at the head of the block. In this case, not all the symbol times the SIC is performed on the stronger channel user. Sometimes, we do perform the SIC on the weaker channel user; such cases, NOMA performs worse than OMA. Thus, we can say that by what percent NOMA is better than OMA. This paper calculates analytically the percentage by which NOMA performs better than OMA in the practical mobile communication systems. We show analytically that the percentage for NOMA being better than OMA is only the function of the ratio of the stronger channel gain variance to weaker. In result, not always, but almost time, NOMA could perform better than OMA.