• KIEAE Journal
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• v.9 no.2
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• pp.9-16
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• 2009

Modern public museums are expanding its role as general cultural facilities. Therefore, the museums that are equipped with convenient and physical environmental features for all ages and types of users are needed. The purpose of this research is to evaluate the application of universal design in common space of the museums and to recommend a set of environmental improvement plans based on which various types of users can decide their choice of museums based on available data on the museums. The scope of this research was limited to seven major public museums located in Seoul, Korea. The spatial scope that was set for this research was common space of the public museums and the scope of the content was about the applicability of universal design. As a result of the research, three major conclusions were reached. First, the application of universal design toward common space in the public museums currently was not prevalent. Second, constant management and application development of universal design are needed. Third, as museums' primary roles and functions become more diverse, a direct application of delicate universal design is a necessary prerequisite to accommodate and fulfill users' needs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.7
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• pp.2212-2230
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• 2014

Cognitive radio (CR) users, known as secondary users (SUs), should avoid interference with primary users (PUs) who own the licensed band, while trying to access it; when the licensed band is unused by the PUs. To detect PUs, spectrum sensing should be performed over in-band channels that are currently in use by SUs. If PUs return to access the band, SUs need to vacate it, disrupting the SUs' communication unless a non-utilized band is discovered. Obtaining a non-utilized band in a short period facilitate seamless communication for SUs and avoid interference on PUs by vacating from the channel immediately. Searching for a non-utilized band can be done through proactive out-of-band (OB) sensing. In this paper, we suggest a proactive OB sensing scheme that minimizes the time required to discover a non-utilized spectrum in order to continue communication. Although, the duration spent on OB sensing reduces the throughput of the CR networks that can be achieved on band being utilized, the lost throughput can be compensated in the new discovered band. We demonstrate that, the effect of our proposed scheme on the throughput owing to OB sensing is insignificant, while exhibiting a very short channel discovery time.

• Smart Media Journal
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• v.1 no.4
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• pp.72-78
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• 2012

SNS supports the formation of relationships between users in common interests and provides services allowing for clique management, sharing contents, and so on. It also has common functions such as acting as primary platforms smoothing the sharing and distribution by combination with various contents. Hence, questionnaire has been conducted to users of all of Twitter, Facebook and KakaoStory, and the factors affected by each service are presented by statistical analyses of the survey and the results are resolved by dividing them into complete and instrumental social capital. This study will be able to provide a standard for users to select SNS according to their purposes and contribute to development of new SNS or improvement of existing ones.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.3
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• pp.19-33
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• 1998

The primary objective of this research was to develop optimal models for masking the road traffic noise with the sound of a waterfall at urban small green spaces. Noise levels were measured at 8 roadside green spaces in SEOUL and questionnaires were randomly distributed to 40 users for evaluating the noise at each site at the same time. College students participated in the experiment for the development of masking models and the developed models were tested by users at 2 green spaces. The major results are as follows ; 1. Traffic noises ranged from 65dBto 70 dB. Users' satisfaction with the noise became considerably low on the basis of 60 dB and it was highly related to noise level. 2. Noise was a main factor to depreciate the amenity of green spaces where its level was more than 60 dB and so it neds to be excluded or reduced the traffic noise at the process of design. 3. Masking effects kept constant independent of the spatial location of masker on condition that masker levels were equal. It was effective when masker was 5-10dB greater than noise level which was masked. 4. As noise level went up, satisfaction ratings about the masked noise became low but masking effects increased in proportion to its level. 5. It was proved that the models were valid through the field experiment.

• Journal of Information Processing Systems
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• v.10 no.4
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• pp.602-617
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• 2014

The performance of a cognitive radio network (CRN) solely depends on how precisely the secondary users can sense the presence or absence of primary users. The incorporation of a spatial false alarm makes deriving the probability of a correct decision a cumbersome task. Previous literature performed this task for the case of a received signal under a Normal probability density function case. In this paper we enhance the previous work, including the impact of carrier frequency, the gain of antennas on both sides, and antenna heights so as to observe the robustness against noise and interference and to make the correct decision of detection. Three small scale fading channels: Rayleigh, Normal, and Weibull were considered to get the real scenario of a CRN in an urban area. The incorporation of a maximal-ratio combining and selection combing with a variation of the number of received antennas have also been studied in order to achieve the correct decision of spectral sensing, so as to serve the cognitive users. Finally, we applied the above concept to a traffic model of the CRN, which we based on a two-dimensional state transition chain.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8C
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• pp.713-719
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• 2010

Collaborative spectrum sensing has been found to be an effective means for detecting the activity of primary users in a fading environment. Most previous works on collaborative spectrum sensing are based on the assumption that the local spectrum sensing decisions of secondary users are statistically independent. However, it may not hold in some practical situations. In this paper, we consider a cognitive radio network where the local spectrum sensing decisions of secondary users are statistically correlated with the same level of correlation if they are next to each other in location and statistically independent, otherwise. Then, for the system, we analyzed the performance of the collaborative spectrum sensing with the AND and the OR fusion rules and found that the scheme with the AND fusion rule performs better than the one with OR fusion rule when the degree of correlation is significant.

• Journal of Distribution Science
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• v.20 no.8
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• pp.105-114
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• 2022

Purpose: The technology acceptance model (TAM) refers to a theory that maps the possibility or extent to which users can accept an innovative technology. The purpose of the current research is to investigate the mediating effect of TAM between online review and behavior intention for promoting golf app's distribution. Research design, data and methodology: In order to examine the relationship between app usage reviews, TAM, and behavioral intentions of golf app participants, the present author collected total 170 responses from South Korean participants based on web-based survey system. The main methodology which was selected by this study is mediation causality analysis that Baron and Kenny suggested. Results: The statistical findings definitely indicated that TAM mediating role exists between the positive emotion of golf app users regarding online reviews and positive behavior intention of golf app, which means that all three steps of mediation causality analysis were statistically significant. Conclusions: The present research concludes that the correct utilization of innovation in the design and implementation of the technology features translates into performance excellence. The model can be used to increase the online presence through innovation as a primary drive toward providing more convenience and accessibility to the users through mobile golf apps.

• Educational Technology International
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• v.12 no.1
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• pp.67-94
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• 2011

The major concern of e-learning environment design is to create and improve artifacts that support human learning. To facilitate effective and efficient learning, e-learning environment designers focused on the contemporary information technologies. Web 2.0 services, which empower users and allow the inter-transforming interactions between users and information technologies, have been increasingly changing the way that people learn. By adapting these Web 2.0 technologies in learning environment, educational technology can facilitate learners' abilities to personalize learning environment. The main purpose of this study is to conceptualize comprehensively constructs for understanding the inter-transforming relationships between learner and learning environment and mutable learning environments' impact on the process through which learners learn and strive to shape their learning environment. As results, this study confirms conceptualization of four constructs by incorporating aspects of design that occur in e-learning environments with Web 2.0 technologies. First, learner-designer refers to active and intentional designer who is tailoring an e-learning environment in the changing context of use. Second, learner's secondary design refers to learner's design based on the primary designs by design experts. Third, transactional interaction refers to learner's inter-changeable, inter-transformative, co-evolutionary interaction with technological environment. Fourth, trans-active learning environment refers to mutable learning environment enacted by users.

• Journal of applied mathematics & informatics
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• v.32 no.1_2
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• pp.129-136
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• 2014

One of the fundamental issues in the design of dynamic spectrum access policy is the modeling of the dynamic behavior of channel occupancy by primary users. Under a Markovian modeling of channel occupancy, a periodic sensing and greedy access policy is known as one of the simple and practical dynamic spectrum access policies in cognitive radio networks. In this paper, the primary occupancy of each channel is modeled as a discrete-time alternating renewal process with generally distributed on- and off-periods. A periodic sensing and greedy access policy is constructed based on the general channel occupancy model. Simulation results show that the proposed policy has better throughput than the policies using channel models with exponentially distributed on- or off-periods.

• Journal of information and communication convergence engineering
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• v.9 no.3
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• pp.251-255
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• 2011

In this paper, we investigate an adaptive cognitive radio (CR) scheme where a sensing duration and a detection threshold for spectrum sensing are adaptively determined according to the channel condition in a fading channel. We optimize the sensing duration and detection threshold of a secondary user to maximize the performance of the secondary user guaranteeing a primary user's secure communication. In addition, we analyze the effect of channel fading on the optimization of the sensing duration and detection threshold. Our numerical results show that the performance of the adaptive CR scheme can be drastically improved if a secondary user can take the advantage of channel information between primary and secondary users.