• Korean Journal of Head & Neck Oncology
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• v.32 no.1
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• pp.21-23
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• 2016

The aim of this report was to present a rare case of a tracheotomy site recurrence after operation and post-operative radiotherapy in head and neck squamous cell carcinoma patient. Tracheotomy site recurrence other than subglottic cancer is very rare in head and neck cancer patient. The granulation tissue around tracheotomy was a fertile "soil" for tumor cell implantation. Midline mucosal sparing block which was used to decreased acute toxicity during post-operative radiotherapy could be facilitating the tumor cell implantation. The head and neck surgeon should try every effort to reduce contamination of cancer cells during operation and consider the entire operative field should be included in post-operative radiation portals.

• Journal of the Korean Operations Research and Management Science Society
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• v.37 no.3
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• pp.57-68
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• 2012

The recent proliferation of various smart devices like the smartphone, tablet PC, and smart TV enables consumers to download various applications from the network and to access private files stored in their desktop server at any time and at any place. The trend of ubiquitous access seems to have become stronger and more diversified toward a ubiquitous network computing environment with the aggressive deployment of commercial cloud services. Recently, many Korean network service providers launched commercial B2C public cloud services, which were widely adopted by smart device users. They include Daum cloud, N drive, ucloud, and uplus box, mostly provided by major Korean telecom companies and portals. This paper aims to explore consumers' adoption behaviors toward the B2C public cloud services that were recently deployed in the Korean market. In order to achieve the goal, we identified key influencing factors that affect the consumers' adoption behaviors, based on an extension of the technology acceptance model (TAM). Several hundred smart device users were surveyed to test the generic regression model with the extended set of TAM variables.

• Journal of Korean Library and Information Science Society
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• v.35 no.1
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• pp.1-17
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• 2004

Most web portals provide a web directory service which selects and classifies web sites according to their subject matter. In order to investigate the directory access behavior of general Korean web users, this study analyzes directory access logs of NAVER, a major Korean web search engine. This study suggests a methodology to classify the total sessions into six different session types. This study also discusses directory access behaviors of the NAVER users by examining the distribution of sessions according to session types, the lengths of navigation within a session, and the most frequently visited categories. It is expected that this study could contribute to the development of more effective web directory services.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.1089-1104
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• 2017

We have developed an information management tool for the EDISON (EDucation-research Integration through Simulation On the Net) open platform. EDISON is, at present, a web-based simulation service for education and research in five computational areas, namely, nanophysics, fluid dynamics, chemistry, structural dynamics, and computer aided optimal design. The EDISON open platform consists of three tiers: EDISON application framework, EDISON middleware, and EDISON infra-resources. The platform provides web portals for education and research in areas such as computational fluid dynamics, computational chemistry, computational nanophysics, computational structural dynamics, and computer aided optimal design along with user service. The main purpose of this research is to test the behavior of the release version of the EDISON Open-Platform under normal operating conditions. This management tool has been implemented using the RESTful API designed in EDISON middleware. The intention is to check co-operation between the middleware and the infrastructure. Suggested tools include User management, Simulation and Job management, and Simulation software (i.e., solver) testing. Finally, it is considered meaningful to develop a management tool that is not supported in other web-based online simulation services.

• Journal of the Korean Society for Library and Information Science
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• v.45 no.1
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• pp.377-393
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• 2011

This study aims to investigate trends of internet searching behavior of users of NAVER, a major Korean search portal. In particular, this study analyzed trends of query submission behaviors, behaviors related to typos, multimedia searching behaviors, and click behaviors. In conducting this study, query logs and click logs of unified search service were analyzed. The results of this study show that there were little changes in the topic and length of queries, the pattern of typos, and multimedia seeking behavior over a year's period. However, click counts of documents have gradually increased over time. The results of this study can be implemented to increase the portal's effective development of internet contents and searching algorithms.

• Journal of KIBIM
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• v.8 no.3
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• pp.12-19
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• 2018

The research aims to find implications of machine learning and urban big data as a way to construct the flexible transportation network system of smart city by responding the urban context changes. This research deals with a problem that existing a bus headway model is difficult to respond urban situations in real-time. Therefore, utilizing the urban big data and machine learning prototyping tool in weathers, traffics, and bus statues, this research presents a flexible headway model to predict bus delay and analyze the result. The prototyping model is composed by real-time data of buses. The data is gathered through public data portals and real time Application Program Interface (API) by the government. These data are fundamental resources to organize interval pattern models of bus operations as traffic environment factors (road speeds, station conditions, weathers, and bus information of operating in real-time). The prototyping model is implemented by the machine learning tool (RapidMiner Studio) and conducted several tests for bus delays prediction according to specific circumstances. As a result, possibilities of transportation system are discussed for promoting the urban efficiency and the citizens' convenience by responding to urban conditions.

• Journal of Information Science Theory and Practice
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• v.5 no.2
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• pp.17-32
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• 2017

We compared nanotechnology web portal requirements using a Kano method, to identify similarities and dissimilarities in Kano-categorizations of features and functions required of nanotechnology among users in universities, government research institutes, and industry. Based upon data obtained from 130 user members of the National Nanotechnology Policy Centre, this study analyzed assessed asymmetries in web users' feelings based on hypothesized provision and non-provision of web portal requirements. In doing this, this study utilized measures and procedures suggested in the literature such as the most frequent-response categorization, customer satisfaction (dissatisfaction) coefficient, category strength and total strength, and Fong test. This study found that overall, sectors were an important factor in explaining the relationships between web portal requirements and user satisfaction/expectations. When these requirements were classified, users' perceptions of information contents requirements were consistent across the sectors, but the other functional requirements including communication and collaborations considerably varied.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.12B
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• pp.1135-1144
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• 2003

In this paper, we proposed a semi-soft handoff mechanism to provide link mobility in IEEE 802.11 wireless LAN environment. Buffers and routing tables in APs and portals are provided in order to reroute frames, which have not been received during handoff time and have been buffered in an old AP, to a new AP after handoff is performed. For the re -routing operation, the MAC routing table should be updated by exchanging information of a mobile terminal between neighbor APs. With our proposed scheme. a wireless LAN node can perform semi soft handoff while changing its attached AP and provide mobile IP and/or real time service like voice over IP. Also, we have done simulation for evaluation of the performance of the proposed scheme. We show that our semi soft handoff mechanism can be applied for real-time service with no frame loss in mobile environment.

• Journal of the Korean Society for information Management
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• v.28 no.1
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• pp.7-22
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• 2011

Internet portals have been revolutionized not only as simple search engines but also as a new space for the Internet users. They have developed to give satisfying search results for academic information users. academic fields. However, their attention was given to the quantity rather than the quality of the results. This tendency is now changing. This study addresses the problems in the search process using the current portal sites and presents an integrated scholarly information service where users can access more organized and trustworthy information linked with online technical keyword dictionary. When a user enter a keyword on a portal site, he/she can access to high quality scholarly information resources linked with keyword. This could assure the user to get an expanded knowledge with confirmation.

• Journal of Information Processing Systems
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• v.16 no.3
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• pp.733-741
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• 2020

A smart dust monitoring system is useful for obtaining information on rough terrain that is difficult for humans to access. One of ways to deploy sensors to gather information in smart dust environment is to use an aircraft in the Amazon rainforest to scatter an enormous amount of small and cheap sensors (or smart dust devices), or to use an unmanned spacecraft to throw the sensors on the moon's surface. However, scattering an enormous amount of smart dust devices creates the difficulty of managing such devices as they can be scattered into inaccessible areas, and also causes problems such as bottlenecks, device failure, and high/low density of devices. Of the various problems that may occur in the smart dust environment, this paper is focused on solving the bottleneck problem. To address this, we propose and construct a three-layered hierarchical smart dust monitoring system that includes relay dust devices (RDDs). An RDD is a smart dust device with relatively higher computing/communicating power than a normal smart dust device. RDDs play a crucial role in reducing traffic load for the system. To validate the proposed system, we use climate data obtained from authorized portals to compare the system with other systems (i.e., non-hierarchical system and simple hierarchical system). Through this comparison, we determined that the transmission processing time is reduced by 49%-50% compared to other systems, and the maximum number of connectable devices can be increased by 16-32 times without compromising the system's operations.