• International Journal of Computer Science & Network Security
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• v.22 no.2
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• pp.145-152
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• 2022

One of the impacts of Covid-19 on education systems has been the shift to online education. This shift has changed the way education is consumed and perceived by students. However, the exact nature of student perception about online education is not known. The aim of this study was to understand the perceptions of Saudi higher education students (e.g., post-school students) about online education during the Covid-19 pandemic. Various aspects of online education including benefits, features and cybersecurity were explored. The data collected were analysed using statistical techniques, especially artificial neural networks, to address the research aims. The key findings were that benefits of online education was perceived by students with positive experience or when ensured of safe use of online platforms without the fear cyber security breaches for which recruitment of a cyber security officer was an important predictor. The issue of whether perception of online education as a necessity only for Covid situation or a lasting option beyond the pandemic is a topic for future research.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.1-20
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• 2022

The basic way to charge vehicles for using road and public transport networks is the entry-exit toll system. This system works by reading Hi-Pass and public transportation cards of the vehicles using card readers. However, the problems of navigating a route in consideration of entry-exit toll systems include the non-additive costs of enumerating routes. This problem is known as an NP-complete task that enumerates all paths and derives the optimal path. So far, the solution to the entry-exit toll system charging has been proposed in the form of transforming the road network. However, unlike in the public transport network where the cards are generalized, this solution has not been found in situations where network expansion is required with a transfer, multi-modes and multiple card readers. Hence, this study introduced the Link Label for a public transportation network composed of card readers in which network expansion is bypassed in selecting the optimal path by enumerating the paths through a one-to-one k-path search. Since the method proposed in this study constructs a relatively small set of paths, finding the optimal path is not burdensome in terms of computing power. In addition, the ease of comparison of sensitivity between paths indicates the possibility of using this method as a generalized means of deriving an optimal path.

• Journal of Information Processing Systems
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• v.13 no.1
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• pp.184-195
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• 2017

In recent decades, the ad hoc network for vehicles has been a core network technology to provide comfort and security to drivers in vehicle environments. However, emerging applications and services require major changes in underlying network models and computing that require new road network planning. Meanwhile, blockchain widely known as one of the disruptive technologies has emerged in recent years, is experiencing rapid development and has the potential to revolutionize intelligent transport systems. Blockchain can be used to build an intelligent, secure, distributed and autonomous transport system. It allows better utilization of the infrastructure and resources of intelligent transport systems, particularly effective for crowdsourcing technology. In this paper, we proposes a vehicle network architecture based on blockchain in the smart city (Block-VN). Block-VN is a reliable and secure architecture that operates in a distributed way to build the new distributed transport management system. We are considering a new network system of vehicles, Block-VN, above them. In addition, we examine how the network of vehicles evolves with paradigms focused on networking and vehicular information. Finally, we discuss service scenarios and design principles for Block-VN.

• Journal of Communications and Networks
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• v.9 no.1
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• pp.56-66
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• 2007

Mobile ad-hoc networks (MANETs) have attracted great research interest in recent years. Among many issues, lack of motivation for participating nodes to collaborate forms a major obstacle to the adoption of MANETs. Many contemporary collaboration enforcement techniques employ reputation mechanisms for nodes to avoid and penalize malicious participants. Reputation information is propagated among participants and updated based on complicated trust relationships to thwart false accusation of benign nodes. The aforementioned strategy suffers from low scalability and is likely to be exploited by adversaries. In this paper, we propose a novel approach to address these problems. With the proposed technique, no reputation information is propagated in the network and malicious nodes cannot cause false penalty to benign hosts. Nodes classify their one-hop neighbors through direct observation and misbehaving nodes are penalized within their localities. Data packets are dynamically rerouted to circumvent selfish nodes. As a result, overall network performance is greatly enhanced. This approach significantly simplifies the collaboration enforcement process, incurs low overhead, and is robust against various malicious behaviors. Simulation results based on different system configurations indicate that the proposed technique can significantly improve network performance with very low communication cost.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.2
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• pp.562-576
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• 2020

The power allocation optimization problem is investigated for improving the physical-layer security in two-way relaying networks, where a full-duplex relay based half-jamming protocol (HJP-FDR) is considered. Specially, by introducing a power splitter factor, HJP-FDR divides the relay's power into two parts: one for forwarding the sources' signals, the other for jamming. An optimization problem for power split factor is first developed, which is proved to be concave and closed-form solution is achieved. Moreover, we formulate a power allocation problem to determine the sources' power subject to the total power constraint. Applying the achieved closed-form solutions to the above-mentioned problems, a two-stage strategy is proposed to implement the overall power allocation. Simulation results highlight the effectiveness of our proposed algorithm and indicate the necessity of optimal power allocation.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.261-264
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• 2001

This paper relates to a node structure of a multiway search tree and a search method using the node structure and, more particularly, to a search method for accelerating its search speed by reducing the depth of each small tree in a multi-way search tree. The proposed idea can increase the number of keys capable of being recorded on a cache line by using one pointer at a node of the multi-way search tree so that the number of branches in a network address search is also increased and thus the tree depth is reduced. As a result, this idea can accelerate the search speed and the speed of the forwarding engine and accomplish a further speed-up by decreasing required memories and thus increasing a memory rate.

• Journal of Korean Academy of Nursing
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• v.40 no.1
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• pp.88-98
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• 2010

Purpose: The purpose of this study was to identify the social network types of elders and to identify differences among latent classes by social network. Methods: The data of 312 elders used in this study were collected from health, welfare, and other facilities and from elders living in the community. The interviews were conducted from July 16 to September 30, 2007 using a standard, structured questionnaire. Descriptive statistics, one way ANOVA with the SPSS 15.0 program and latent class analysis using Maximum Likelihood Latent Structure Analysis (MLLSA) program were used to analyze the data. Results: Using latent class analysis, social network types among older adults were identified as diverse for 58.0% of the sample, as family for 34.0%, and as isolated for 8.0%. The health status of respondents differed significantly by network type. Elders in diverse networks had significantly higher health status and elders in isolated networks had significantly lower physical health status on average than those in all other networks. Conclusion: The results of this study suggest that these network types have important practical implications for health status of elders. Social service programs should focus on different groups based on social network type and promote social support and social integration.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.3
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• pp.155-160
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• 2011

IPTV functions not only as media player that does play the broadcasting industry's contents, also as the gateway is guaranteed of QoS(Quality of Service). This is for free contents-sharing that device stores contents using home network circumstance, and is for watching with seamless network service. Also this have required next QoS model that can handle stably as it may contain more data of the small computing device in next generation home system. We need ubiquitous-oriented QoS's design and development project that focuses on internal and external media service, not the existing QoS nor one-sided QoS of media sevice industry. This paper focuses on network module development. This supports IPTV in media industry and two-way capability of QoS highlighting multimedia service in network industry. In additional, this can handle stably the multiplex signal of USN/RFID as the representative ubiquitous and home network that services high-speed wire and wireless interface, and support the seamless u-QoS.

• The Transactions of the Korea Information Processing Society
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• v.4 no.5
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• pp.1319-1326
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• 1997

The Internet is a very convenient neteork, but not always a So.many orvanizations often require administrative security policies when they want to connect with ther organizations thtough a pubic network.A firewall is one way of protecting an internal network from the untrusted extemal network with a mechanism for selectively permiting or blocking traffic between the intermal network and the extermal network. The firewall also provides some limited Intemet access such as Ftp.Telet, etc.Usually , through a firewall system, X applications running on the extermal network may not access an X display on the intermal network.Thus, X applications run-ning on the extemal network are not supported through the usual firewall.In this paper, we propose a method of suppoting X application programs effedtively dffectvely through the firewall, overcoming this restriction.

• Educational Technology International
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• v.13 no.1
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• pp.1-25
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• 2012

Despite the relatively short history of Social Network Sites or Services (SNS), it has quickly gained popularity with more than seven hundred million users all over the globe. The SNS emerged as one of the strongest cultural influences for the contemporary society. The SNS would provide both chances and challenges for Education. The main purpose of the article was to explore the way education react and adapt to the emergence of social network and SNS. It tried to provide major theoretical grounds that bridge education and social network. In the due process, the researchers have examined the curriculum and instructional design process of education from the perspective of disruptive and sustainable aspect of SNS technology. Consequently, four major theoretical grounds were identified and reviewed: Gibson's theory of affordance, Vygotsky's social constructivism, Rha's human visual intelligence theory, and the network theory. By investigating these theories, the educational potentials of social network and SNS were emerged. The SNS was viewed as a new medium with abundant potentials of expanding the learning space, empowering the affective aspects of learning, and facilitating the formation of group intelligence. Finally, some future implications and challenges of SNS were suggested.