• Journal of the Ergonomics Society of Korea
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• v.29 no.4
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• pp.655-659
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• 2010

The objective of this study is to quantitatively incorporate user observation into usability evaluation of mobile interfaces using monitoring techniques in first- and third-person points of view. In this study, an experiment was conducted to monitor and record users' behavior using Ergoneers Dikablis, a gaze tracking device. The experiment was done with 2 mobile phones each with a button keypad interface and a touchscreen interface for comparative analysis. The subjects included 20 people who have similar experiences and proficiency in using mobile devices. Data from video recordings were coded with Noldus Observer XT to find usage patterns and to gather quantitative data for analysis in terms of effectiveness, efficiency and satisfaction. Results showed that the button keypad interface was generally better than the touchcreen interface. The movements of the fingers and gaze were much simpler when performing given tasks on the button keypad interface. While previous studies have mostly evaluated usability with performance measures by only looking at task results, this study can be expected to contribute by suggesting a method in which the behavioral patterns of interaction is evaluated.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3335-3356
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• 2015

In this paper, we analyze the connectivity of cognitive radio ad-hoc networks in a log-normal shadow fading environment. Considering secondary user and primary user's locations and primary user's active state are randomly distributed according to a homogeneous Poisson process and taking into account the spectrum sensing efficiency of secondary user, we derive mathematical models to investigate the connectivity of cognitive radio ad-hoc networks in three aspects and compare with the connectivity of ad-hoc networks. First, from the viewpoint of a secondary user, we study the communication probability of that secondary user. Second, we examine the possibility that two secondary users can establish a direct communication link between them. Finally, we extend to the case of finding the probability that two arbitrary secondary users can communicate via multi-hop path. We verify the correctness of our analytical approach by comparing with simulations. The numerical results show that in cognitive radio ad-hoc networks, high fading variance helps to remarkably improve connectivity behavior in the same condition of secondary user's density and primary user's average active rate. Furthermore, the impact of shadowing on wireless connection probability dominates that of primary user's average active rate. Finally, the spectrum sensing efficiency of secondary user significantly impacts the connectivity features. The analysis in this paper provides an efficient way for system designers to characterize and optimize the connectivity of cognitive radio ad-hoc networks in practical wireless environment.

• Journal of Korean Library and Information Science Society
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• v.49 no.2
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• pp.357-388
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• 2018

This study aims to analyze library user and circulation status based on the bigdata logs to identify characteristics by user group and propose methods for efficient management of library. The logs to be analyzed consist of user information, circulation information, service usage information registered at the National Library of Korea, Sejong. The user information logs contain 107,369 age data, 106,918 gender data, 106,838 residential data. The circulation information logs contain 536,083 circulation user data, 6,509,369 circulation count data, and the service usage information logs contain 82,813 data. For the analysis of characteristics by user group, the data were used for analyzing user status by age, gender, residence and circulation status by year, month, day. In addition, this study conducts FGI(Focus Group Interview) and linkage analysis with external data to identify factors for analysis results. Based on analysis results, improvement methods for helping library make effective decision-making were proposed. This study analyze empirically user and circulation status based on bigdata logs, and it has significance for being different form proceeding researches with less analysis data.

• Journal of Information Processing Systems
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• v.15 no.4
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• pp.717-723
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• 2019

Smart systems and services aim to facilitate growing urban populations and their prospects of virtual-real social behaviors, gig economies, factory automation, knowledge-based workforce, integrated societies, modern living, among many more. To satisfy these objectives, smart systems and services must comprises of a complex set of features such as security, ease of use and user friendliness, manageability, scalability, adaptivity, intelligent behavior, and personalization. Recently, artificial intelligence (AI) is realized as a data-driven technology to provide an efficient knowledge representation, semantic modeling, and can support a cognitive behavior aspect of the system. In this paper, an integration of AI with the smart systems and services is presented to mitigate the existing challenges. Several novel researches work in terms of frameworks, architectures, paradigms, and algorithms are discussed to provide possible solutions against the existing challenges in the AI-based smart systems and services. Such novel research works involve efficient shape image retrieval, speech signal processing, dynamic thermal rating, advanced persistent threat tactics, user authentication, and so on.

• The Journal of Information Systems
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• v.28 no.1
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• pp.97-114
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• 2019

Purpose The purpose of this study is to deduct the factors for explaining the economic behavior of an Internet user who provides personal information notwithstanding the concern about an invasion of privacy based on the Information Privacy Calculus Theory and Communication Privacy Management Theory. Design/methodology/approach This study made a design of the research model by integrating the factors deducted from the computation theory of information privacy with the factors deducted from the management theory of communication privacy on the basis of the Dual-Process Theory. Findings According to the empirical analysis result, this study confirmed that the Privacy Concern about forms through the Perceived Privacy Risk derived from the Disposition to value Privacy. In addition, this study confirmed that the behavior of an Internet user involved in personal information offering occurs due to the Perceived Benefits contradicting the Privacy Concern.

• Journal of Korea Game Society
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• v.15 no.6
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• pp.41-54
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• 2015

Despite a great performance of Korean online game in Chinese online game market, Korean companies were faced with decreasing market positions in China from 2006. To overcome this problem, I will suggest a research model about determinant of repurchase behavior of on-line game user and moderation effect of online review. Data collected from questionnaire survey were used in empirical analysis on research hypothesis through moderated multiple regression method. There are several conclusions as such; first, perceived value and loyalty of consumer have great positive relationships with repurchase behavior. Second, online review has positive direct influence on repurchase behavior and moderation effect of relationships among them. Third, game company has great efforts to develop online games and game contents which were guaranteed before in price, quality, information, and accurate consideration of online review.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.352-354
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• 2005

본 연구는 홈 네트워크 인터페이스 모델에서의 관측 데이터를 기반으로 기존의 시스템 중심의 분석이 아닌 사용자 행위 분석에 초점을 두고 있다. 다양한 사용자 행위 자료를 분석하여 사용자 행위 모델링을 하는 것은 어려운 작업이다. 우리는 가능한 제한된 사용자 행위를 추출하기위해 목적(Goal) 지향의 사용자 행위분석을 제안하며, 정확한 사용자 행위 및 패턴을 식별/추출하기위해, 분석 자동화 도구를 구현하였다. 이는 행위 패턴의 중복성 및 빈도수를 측정하여, 사용자의 중요한 행위를 식별하기 위함이다. 본 논문에서는 수작업의 오류를 방지하고 사용자의 중요한 행위 분석을 통해 시스템을 쉽게 모델링 및 개발을 하고자, 사용자 행위 분석 도구인 UBA(User Behavior Analyst)를 제안한다.

• Structural Engineering and Mechanics
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• v.27 no.4
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• pp.477-499
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• 2007

The main purpose of this paper is to investigate the ultimate behavior of steel cable-stayed bridges with design variables and compare the validity and applicability of computational methods for evaluating ultimate load capacity of cable-stayed bridges. The methods considered in this paper are elastic buckling analysis, inelastic buckling analysis and nonlinear elasto-plastic analysis. Elastic buckling analysis uses a numerical eigenvalue calculation without considering geometric nonlinearities of cable-stayed bridges and the inelastic material behavior of main components. Inelastic buckling analysis uses an iterative eigenvalue calculation to consider inelastic material behavior, but cannot consider geometric nonlinearities of cable-stayed bridges. The tangent modulus concept with the column strength curve prescribed in AASHTO LRFD is used to consider inelastic buckling behavior. Detailed procedures of inelastic buckling analysis are presented and corresponding computer codes were developed. In contrast, nonlinear elasto-plastic analysis uses an incremental-iterative method and can consider both geometric nonlinearities and inelastic material behavior of a cable-stayed bridge. Proprietary software ABAQUS are used and user-subroutines are newly written to update equivalent modulus of cables to consider geometric nonlinearity due to cable sags at each increment step. Ultimate load capacities with the three analyses are evaluated for numerical models of cable-stayed bridges that have center spans of 600 m, 900 m and 1200 m with different girder depths and live load cases. The results show that inelastic buckling analysis is an effective approximation method, as a simple and fast alternative, to obtain ultimate load capacity of long span cable-stayed bridges, whereas elastic buckling analysis greatly overestimates the overall stability of cable-stayed bridges.

• 한국HCI학회:학술대회논문집
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• 2006.02b
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• pp.334-339
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• 2006

주거환경의 변화는 주거공간을 구성하고 있는 제품을 더 이상 독립된 구조가 아닌 서로 네트워크로 연결된 하나의 제품 및 서비스로 인식될 필요성을 나타내고 있다. 따라서, 제품 및 서비스 컨셉 도출을 위한 사용자 조사 단계에서 사용자의 행위 관찰 시, 관찰의 범위가 기존의 개별 제품을 사용하는 환경 중심에서 전체 제품을 사용하는 환경으로 확장 될 필요가 있다. 본 연구에서는 주거공간에서 제품 사용의 관찰범위를 개별제품사용환경과 전체제품사용환경으로 분류하여 각각의 관찰범위에서의 사용자 행위 분석 데이터가 어떠한 차이를 갖는지 관찰법(Ethnography)을 이용한 사례연구를 통해 비교 분석하였다. 본 연구의 결과는 추후 주거환경을 구성하는 제품 및 서비스 개발 시 목적에 적합한 관찰범위를 선택하는데 있어 도움이 될 것이며, 기반이 되는 자료로 활용될 수 있을 것이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.544-546
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• 2011

Due to the explosive growth of online social network users, large numbers of users discover these social network sites are a place where they can be able to spend their spare time, share feelings, ideas freely, and to search for new friends or partners. These web sites give an opportunity for its users to socialize with new people and to keep in touch or reconnect with current or old friends and families across disperse continents via these web sites, which traditionally replace the traditional methods. These social network web sites need careful investigations and findings on the usability for effective interactivity and more usability. However, little research might have previously invested on the usability of these on social network web sites. Therefore, we propose a new framework to study the usability of these social network sites. We namely call our framework "Interactivity". This framework will enable us to assess the usability of the social network sites. It will provide an overview of the user's behavior while interacting in these social network web sites. Measurement of the interactivity will be measured using Camtasia software. This software will entirely capture the interactivity of users including the screen and the movements, which the screen and the motion of the user action will undergo to analysis at the end of our research.