• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.11
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• pp.4224-4243
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• 2021

Cognitive radio (CR) is a feasible intelligent technology and can be used as an effective solution to spectrum scarcity and underutilization. As the key function of CR, cooperative spectrum sensing (CSS) is able to effectively prevent the harmful interference with primary users (PUs) and identify the available spectrum resources by exploiting the spatial diversity of multiple secondary users (SUs). However, the open nature of the cognitive radio networks (CRNs) framework makes CSS face many security threats, such as, the malicious user (MU) launches Byzantine attack to undermine CRNs. For this aim, we make an in-depth analysis of the motive and purpose from the MU's perspective in the interweave CR system, aiming to provide the future guideline for defense strategies. First, we formulate a dynamic Byzantine attack model by analyzing Byzantine behaviors in the process of CSS. On the basis of this, we further make an investigation on the condition of making the fusion center (FC) blind when the fusion rule is unknown for the MU. Moreover, the throughput and interference to the primary network are taken into consideration to evaluate the impact of Byzantine attack on the interweave CR system, and then analyze the optimal strategy of Byzantine attack when the fusion rule is known. Finally, theoretical proofs and simulation results verify the correctness and effectiveness of analyses about the impact of Byzantine attack strategy on the throughput and interference.

• Journal of the Ergonomics Society of Korea
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• v.29 no.4
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• pp.575-584
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• 2010

The aim of study is to suggest the design procedure of automobile headlamp by considering driver's experience in regard of the visibility and glare during nighttime driving. The characteristics of driver were investigated in terms of the drivers' cognitive ability and reaction time, headlamp specification and visibility, light source and glare. And, the degree of visual discomfort was categorized and recognized as a tool to represent the subjective user experience. The UX point of view was stated when the existing results were seemingly lacking of it. The visual comfort and safety of elderly drivers were also discussed by reviewing the studies of ageing regarding the visibility and driving responses. Finally, this study suggested how to reduce the negative effect of nighttime driving due to the height of headlamp, angle of lighting, color spectrum, discomfort glare, source of light by using the UX perspective and methodology.

• Journal of Korean Society of Archives and Records Management
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• v.11 no.1
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• pp.231-252
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• 2011

User needs and their usage motivations are critical components of web portal success, yet limited studies have been conducted with the constituents of good cultural heritage archive portals from the user perspective. This study proposes a quality assessment model from the user perspective. To overcome the intrinsic biases, the triangulation approach was chosen for building a research model. The proposed research model adapts three existing web portal quality models: service quality model, data quality model, and technology acceptance model. A 99-item instrument is suggested to investigate the proposed model. In the next phase of research, the instrument will be tested for its construct validity, and the research model will be empirically tested.

• The Journal of Society for e-Business Studies
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• v.20 no.1
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• pp.167-182
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• 2015

The concept of Smart home is receiving a huge attention as a future living environment because of its advantages for elderly and disabled to maintain their quality of life. Smart home is a place equipped with integration of technology and services and closely intertwined with occupant's lifestyle. Therefore it is critical to consider the user's actual needs for ensuring satisfaction. However despite growing researches on user values for smart home, there have been few studies clearly categorizing smart home service and stating user values depending on characteristics of service. Thus, the aim of this research is to classify smart home services on user's perspective, and reveal user values for each smart home services. Through the in-depth literature review, we elicited technology-related user values and service-related user values, and state classification for smart home service. Also the relationship between user values and each smart home services were revealed. The results of this research should help to reflect user's actual needs for designing smart home services.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.4
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• pp.35-55
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• 2008

The primary objective of his study is to investigate the factors influencing the implementation performance of K public corporation's ERP system from end user perspective. For this purpose, a research model and hypotheses are developed based on the literature reviews of IS Success Models. Data has been collected from 276 users who have used ERP system in K public corporation and the research hypotheses were tested using covariance structure model analysis. The hypotheses test results of this study are summarized as follows. Firstly, system quality has a positive influence on system usage, but information quality and service quality do not have significant influence on system usage. Secondly, all of three quality factors which are information quality, system quality, and service quality, have positive influence on user satisfaction. Lastly, both of system usage and user satisfaction have positive influence on user performance. From the analyses, this research ends with implications, as well as limitations and future research directions.

• Journal of People, Plants, and Environment
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• v.22 no.5
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• pp.525-539
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• 2019

Much research has been conducted on user behavior by taking surveys and interviews to plan the green space effectively. However, there is a limitation in understanding detailed user characteristics such as personalities and values. This study applied the Persona-based Scenario Method (PSM) to Hongneung Experimental Forest to understand the detailed needs and behaviors of the users in the forest recreation area. The PSM is a user experience modeling technique, which tries to understand the users by describing the type of users as real people. This study 1) extracts the factors of visitor recreation activities in Hongneung Experimental Forest based on the results of the survey, 2) develops user personas based on the results of survey and comes up with activity factors, and 3) designs user scenarios. As a result of applying the PSM, 64 factors of visitor activities were derived from the observation survey in 14 sites of Hongneung Experimental Forest and 25 key factors of visitor activities were chosen through observer's brainstorming. Second, three types of personas were developed considering the key factors and the results of user characteristics with quantitative and qualitative analysis. Lastly, context scenarios were designed by applying the key factors of visitor recreation activities to the persona model. We identified the design problems of the space and design requirements through the scenarios. This study has significance in that it takes an approach from the user perspective and was applied to the forest recreation area, which was mainly used in product design. The developed personas could be used for deriving design elements and setting the direction for planning considering detailed needs, behaviors and characteristics of users.

• ETRI Journal
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• v.32 no.6
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• pp.843-853
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• 2010

A successful deployment of multimedia applications over wireless environments entails improving the quality of service (QoS), not only from a technical point of view, but also considering the quality of experience (QoE) from the final user's perception. Although objective QoE measure models avoid the difficulties of subjective surveys, subjective QoE assessments are essential to understand the way users evaluate the QoS. In this work, we study the effect of a wide range of parameters on the QoE of VVoIP applications in a real wireless scenario. Through a complete statistical analysis of users' ratings, we identify the following facts. Although the use of VVoIP in wireless networks does not yet represent an advantage for users, there are great expectations for all applications under study, and with greater popularity comes higher expectations. It is easier for respondents to identify good behavior than poor behavior. Whereas the respondents' frequency of Internet use does not impact on the scores, respondents' gender does. Finally, the most determining parameters of quality from a user's perspective were instability, video quality, voice distortion, usefulness, and graphical interface.

• The Journal of the Korea Contents Association
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• v.17 no.12
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• pp.34-48
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• 2017

The narratives of the digital age have attempted interactions, and the interactive storytelling represented by the Branch Narratives has a problem of the expensive production cost of many optional implementations and poor narrative compared to linear story. As an alternative to this, this study proposes a user-oriented storytelling using user's personality traits. Using the Enneagram, a model of human psyche, and the Actantial model of the semiotician Greimas, when stories and characters are the same, the story could be reconstructed by deriving different topics from the same story according to the user's Enneagram personality type. The theme is determined by defining the axis of the desire of the Actantial model by respectively setting the character with the user's Enneagram type as the subject and the core value in the type as the object. The axis of Power could be defined by the stress and security points in Enneagram. In this way, we can derive the themes of 9 Enneagram types and the corresponding Actantial model and make plots. The users will appreciate one of these reconstructed plots in different perspectives and themes, depending on their personality type. In this study, we applied the above methodology to the story of the pansori novel "Tokkijeon". User-centered storytelling is a new attempt to predict user's choice and reconstruct the story based on the user's personality and perspective.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.32 no.4
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• pp.135-159
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• 2021

This study aims to analyze communication and experiences between public libraries and to identify these factors affect user satisfaction. Customer experience management (CEM), which is currently used in various fields of management and marketing, was applied to segment and analyze user experiences. After reviewing CEM research in marketing and management to derive user experience points, set physical environment, human factors, communication, and service as independent variables, emotional pleasure as parameters, and user satisfaction as dependent variables. Based on this, questionnaire items were constructed. The survey method was conducted in two ways, online and offline (face-to-face), and statistical analysis was performed based on a total of 60 questionnaires collected. The results indicate the higher the user's experience with the physical environment and convenience, the higher the satisfaction level, but library accessibility had no significant effect. In addition, library staff attitude and problem-solving ability had a great influence on user satisfaction, and problem-solving ability had a more important influence than kindness and emotional pleasure was found to have an mediating effect.

• 한국경영정보학회:학술대회논문집
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• 2007.11a
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• pp.123-128
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• 2007

It has been argued that Enterprise systems (ES) implementations are overshadowed by a high failure rate despite their promised benefits. One of the commonly cited reasons for ES implementation failures in the context of mandatory use is end-user's unwillingness or sabotage to adopt or use systems. Considering that the appropriate management of expectations may play an important role in making positive behavior toward newly implemented systems, this study examines the effect of outcome expectations on the system use activity in the mandatory use context of information systems from the Social Cognitive Theory perspective. Structural equation model analysis using LISREL 8.7 provides significant support for the proposed relationships. The empirical results suggest that outcome expectations and user satisfaction have positive effects on system use activity conceptualized by immersion, reinvention, and learning. Theoretical and practical implications of the study shed some light on how to improve system use activity in the mandatory use context of information systems.