• Journal of Digital Convergence
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• v.10 no.8
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• pp.341-346
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• 2012

This paper reports the findings of research into the effect of flow experience and internet addiction on e-learning participation. The total number of access, playing time of contents and lag time (time between content upload and first access) were investigated as e-learning participation by analyzing web log data. The paper also examines the relationship between academic achievement and e-learning participation. The results suggest that the flow experience significantly correlates with all variables related with e-learning participation and internet addiction significantly correlates with lag time. It is found that female students significantly access more, longer and have shorter lag time than their male counterparts. It also suggest total number of access, lag time and gender difference have significant effect on academic achievement.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.13 no.2
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• pp.75-96
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• 2002

This is a user study of the public access to the Internet at public libraries in Busan and Kyungnam province. The mainstream of users was identified as a typical 'information rich'. It was found that public libraries were not successful in leading the traditional non-users into the libraries with public access to the Internet in libraries. For users the most attractive feature of the service was the fact that it was given for free, while they were not value the professional guidance of librarians. Upgrade of hardwares and telecommunication infrastructure was at the highest priority of the users want list, Some strategies for the public access to the Internet at public libraries were proposed.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.222-225
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• 2001

Policy introducing open access to the wireless network has been under discussion in the Korean mobile telecommunications industry. The policy, which directs mobile operators to allow mobile portals other than their own ones to access their network and subscribers, is expected to vitalize mobile Internet market through competition among portals. This study analyzes the impact of the policy in terms of welfare of mobile Internet users and profit of mobile contents providers. We also cover the influence of mobile Internet fee on anticipated results of the policy

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2001.11a
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• pp.31-35
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• 2001

Recent trends require that access to the device/equipment information be provided from several locations or anywhere in the enterprise. One example is virtual machine/manufacturing system (VMS) where predictive maintenance is performed both on factory floor and in remote site through internet ［1］. Internet access is increasingly available and affordable, and along with the "internet" is the backbone of modern enterprise data networks. Typical functions of such a system includes monitoring and control for diagnosis and remedy action in realizing preventive maintenance.(omitted)

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.3
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• pp.1315-1329
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• 2018

Ciphertext-policy attribute-based encryption (CP-ABE) associates ciphertext with access policies. Only when the user's attributes satisfy the ciphertext's policy, they can be capable to decrypt the ciphertext. Expressivity and security are the two directions for the research of CP-ABE. Most of the existing schemes only consider monotonic access structures are selectively secure, resulting in lower expressivity and lower security. Therefore, fully secure CP-ABE schemes with non-monotonic access structure are desired. In the existing fully secure non-monotonic access structure CP-ABE schemes, the attributes that are set is bounded and a one-use constraint is required by these projects on attributes, and efficiency will be lost. In this paper, to overcome the flaw referred to above, we propose a new fully secure non-monotonic access structure CP-ABE. Our proposition enforces no constraints on the scale of the attributes that are set and permits attributes' unrestricted utilization. Furthermore, the scheme's public parameters are composed of a constant number of group elements. We further compare the performance of our scheme with former non-monotonic access structure ABE schemes. It is shown that our scheme has relatively lower computation cost and stronger security.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.9
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• pp.2052-2072
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• 2012

Access control is an essential security component in protecting sensitive data and services from unauthorized access to the resources in mission-critical Cyber-Physical Systems (CPSs). CPSs are different from conventional information processing systems in such that they involve interactions between the cyber world and the physical world. Therefore, existing access control models cannot be used directly and even become disabled in an emergency situation. This paper proposes an adaptive Access Control model for Emergences (AC4E) for mission-critical CPSs. The principal aim of AC4E is to control the criticalities in these systems by executing corresponding responsive actions. AC4E not only provides the ability to control access to data and services in normal situations, but also grants the correct set of access privileges, at the correct time, to the correct set of subjects in emergency situations. It can facilitate adaptively responsive actions altering the privileges to specific subjects in a proactive manner without the need for any explicit access requests. A semiformal validation of the AC4E model is presented, with respect to responsiveness, correctness, safety, non-repudiation and concurrency, respectively. Then a case study is given to demonstrate how the AC4E model detects, responds, and controls the emergency events for a typical CPS adaptively in a proactive manner. Eventually, a wide set of simulations and performance comparisons of the proposed AC4E model are presented.

• Journal of Information Science Theory and Practice
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• v.8 no.2
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• pp.45-54
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• 2020

Access to relevant information determines the quality of life of an individual in society and the academe. Academic institutions have established information literacy programmes to enhance students' access to information. With the elevation of colleges of education to tertiary status in Ghana, pre-service teachers are now required to conduct research to improve their reflective thinking in order to be certified. However, the information access skills of students in colleges of education in Ghana are uncertain. This study draws empirical evidence from students in the Nusrat Jahan Ahmadiyya College of Education, Wa, Ghana on their information access skills. Primary data were collected from 303 respondents from the college using a stratified sampling procedure. The data were collected using a questionnaire and analysed using descriptive statistics. The results indicate that information is available to students through different sources such as the Internet, libraries, and contact with friends and authorities. However, students were limited in respect to access to relevant online resources for their academic activities due to inadequate information access skills. Potential solutions are discussed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4269-4292
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• 2014

Currently, increasing numbers of access points (AP) are being deployed in enterprise offices, campuses and municipal downtowns for flexible Internet connectivity, but most of these access points are idle or redundant most of the time, which causes significant energy waste. Therefore, with respect to power conservation, applying energy efficient strategies in WIFI networks is strongly advocated. One feasible method is dynamically managing network resources, particularly APs, by powering devices on or off. However, when an AP is powered on, the device is initialized through a long boot time, during which period clients cannot be associated with it; therefore, the network performance would be greatly impacted. In this paper, based on a global view of an entire WLAN, we propose an AP selection technology, known as Temporary Access Selection (TAS). The criterion of TAS is a fusion metric consisting of two evaluation indexes which are based on throughput and battery life, respectively. TAS is both service and clients' preference specific through balancing the data rate, battery life and packet size. TAS also works well independently in traditional WLANs in which no energy efficient strategy is deployed. Moreover, this paper demonstrates the feasibility and performance of TAS through experiments and simulations with Network Simulator version 3 (NS3).

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.1
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• pp.185-201
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• 2023

Grant-free random access (GFRA) can reduce the access delay and signaling cost, and satisfy the short transmission packet and strict delay constraints requirement in internet of things (IoT). IoT is a major trend in the future, which is characterized by the variety of applications and devices. However, most existing studies on GFRA only consider a single type of device and omit the effect of access delay. In this paper, we study GFRA in multicell massive multipleinput multiple-output (MIMO) systems where different types of devices with various configurations and requirements co-exist. By introducing the backoff mechanism, each device is randomly activated according to the backoff parameter, and active devices randomly select an orthogonal pilot sequence from a predefined pilot pool. An analytical approximation of the average spectral efficiency for each type of device is derived. Based on it, we obtain the optimal backoff parameter for each type of devices under their delay constraints. It is found that the optimal backoff parameters are closely related to the device number and delay constraint. In general, devices that have larger quantity should have more backoff time before they are allowed to access. However, as the delay constraint become stricter, the required backoff time reduces gradually, and the device with larger quantity may have less backoff time than that with smaller quantity when its delay constraint is extremely strict. When the pilot length is short, the effect of delay constraints mentioned above works more obviously.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.216-219
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• 2000

Recently, with the advent of satellite communication technologies, network access services through satellites have emerged as an alternaive to existing access network services. Of satellite access services including multimedia services, the high speed internet access service will be one of the important services. Particularly, the efficient transportation of real time internet traffic seems very essential. The aim of this research is to examine the applicability of the IETF RTP protocol in the satellite access network. The RTP has been developed for the QoS-met tranportation protocol of real time traffic over the existing best-effort internet. This paper summmarizes the RW protocol, and desciribes the architecture and the data structure of the implementation of the RTP.