• International Journal of Knowledge Content Development & Technology
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• v.7 no.3
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• pp.67-86
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• 2017

The emergence of smart devices such as smartphones (e.g., iPhone) and tablets (e.g., iPad) may enhance e-learning by increasing communication and collaborative learning outside the classroom. These devices also facilitate the use of online technologies such as Facebook. However, the adaptation of Learning Management System (LMS) services to mobile devices took longer than social networks or online tools such as Facebook and Twitter have already been long used via smartphone. The main purposes of this study are to explore students' skill levels of LMS (Moodle) and their knowledge of online tools or technologies and then examine if there is a correlation between smartphone use and using of online tools and Moodle in learning. The study conducted among 173 students in the Department of Information Studies (DIS) in Oman, using online survey. The study found that most students demonstrated high levels of accessing course/subject materials and regularly engaging with studies of using LMSs. YouTube, Wikipedia and Facebook were clearly recorded as the most popular sites among students while LinkedIn and Academia.edu were two online tools that had never been heard of by over half of the 142 participants. Emailing and searching are recorded the most popular online learning activities among students. The study concluded that students prefer to use smartphone for accessing these tools rather than using it to access LMSs, while a positive correlation was found between the use of these tools and smartphones, but there was no correlation between smartphones and using LMSs.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.5
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• pp.39-50
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• 2014

Today people use a smartphone as a tool for enjoying personal hobbies or entertaining contents as well as communication media. Most of the traditional game-specific platforms have transferred to smartphones equipped with social network games that integrate games with human relationships. As average life span of most games has been shortened gradually, game companies should be ready to develop new games to meet user needs. In this study we investigate the acceptance of social games, enjoyable by users and their friends linked in social networks. Since user behavior of social games may show cultural differences by country, we perform a comparative study on acceptance of social games between Korean and Chinese users. The structural relationships among factors affecting social game adoption have been analyzed focusing on differences between Korean and Chinese. We analyze similarities and differences of adoption mechanism in two countries and present some practical implications for related industry.

• Convergence Security Journal
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• v.13 no.4
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• pp.19-25
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• 2013

The increasing demand for fast, flexible and guaranteed Quality of Service (QoS) in core networks has caused to deploy MultiProtocol Label Switching (MPLS) and Generalized MPLS (GMPLS) control plane. In GMPLS control plane, path computation and cooperation processes are one of the crucial element to maintain an acceptable level of service. The Internet Engineering Task Force (IETF) has proposed the Path Computation Element (PCE) architecture. The PCE is a dedicated network element devoted to path computation process and communications between Path Computation Clients (PCC) and PCEs is realized through the PCE Protocol (PCEP). This paper examines the PCE-based path computation architecture to include the design and implementation of PCEP. The functional modules including Finite State Machine (FSM) and related key design issues of each state are presented. In particular we also discuss internal/external protocol interfaces that efficiently control the communication channels.

• Research in Community and Public Health Nursing
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• v.29 no.2
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• pp.244-256
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• 2018

Purpose: This study tried to understand discourses of life-sustaining treatments in general daily and healthcare newspapers. Methods: A text-network analysis was conducted using the NetMiner program. Firstly, 572 articles from 11 daily newspapers and 258 articles from 8 healthcare newspapers were collected, which were published from August 2013 to October 2016. Secondly, keywords (semantic morphemes) were extracted from the articles and rearranged by removing stop-words, refining similar words, excluding non-relevant words, and defining meaningful phrases. Finally, co-occurrence matrices of the keywords with a frequency of 30 times or higher were developed and statistical measures-indices of degree and betweenness centrality, ego-networks, and clustering-were obtained. Results: In the general daily and healthcare newspapers, the top eight core keywords were common: "patients," "death," "LST (life-sustaining treatments)," "hospice palliative care," "hospitals," "family," "opinion," and "withdrawal." There were also common subtopics shared by the general daily and healthcare newspapers: withdrawal of LST, hospice palliative care, National Bioethics Review Committee, and self-determination and proxy decision of patients and family. Additionally, the general daily newspapers included diverse social interest or events like well-dying, euthanasia, and the death of farmer Baek Nam-ki, whereas the healthcare newspapers discussed problems of the relevant laws, and insufficient infrastructure and low reimbursement for hospice-palliative care. Conclusion: The discourse that withdrawal of futile LST should be allowed according to the patient's will was consistent in the newspapers. Given that newspaper articles influence knowledge and attitudes of the public, RNs are recommended to participate actively in public communication on LST.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.6A
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• pp.386-396
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• 2003

Recently, mobile communication systems have supported various services including internet from voice centric service as they evolve toward 3G. To accommodate the increasing number of users, an AAL2 multiplexing scheme is introduced in the UTRAN tub interface for link efficiency. However, limited radio resources and different requirements of various services make it difficult to guarantee the QoS requirements at radio access networks. The conventional AAL2/ATM multiplexing systems focused on the multiplexing efficiency of voice anddata services and QoS issues of real time and non real time services. In this paper, we classfy various services according to QoS requirements and propose AAL2/ATM multiplexing schemes using statistical multiplexing and scheduling with a rather simple structure to guarantee the given requirements. Simulation results show that the proposed schemes perform better than the conventional schemes to guarantee QoS requirements of various services.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9B
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• pp.1542-1550
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• 2000

Fiber optic link systems based on SCM scheme are widely used as efficient and economic RF signal links between base station and a central station in mobile communication networks. However, its performance can be seriously limited depending on the operational conditions of not only the optical transmission system but also the wireless link in various environments. In this paper, we propose an analytic model for performance analyses of the SCM fiber optic link for CDMA RF signal transmission in various link environments. We present optimal operational conditions taking account of the nonlinear effects of the optical transmission system, and the multiple access interference produced at the wireless link. It has been shown through the BER analyses in this paper that the selection of optical modulation index of the SCM fiber optic links can be found optimally to minimize the fiber optic link noises and intermodulation distortion due to LD.

• Journal of Communications and Networks
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• v.18 no.3
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• pp.387-396
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• 2016

Multiuser communication has been an important research area of underwater acoustic communications and networking. This paper studies the use of adaptive orthogonal frequency-division multiple access (OFDMA) in a downlink scenario, where a central node sends data to multiple distributed nodes simultaneously. In practical implementations, the instantaneous channel state information (CSI) cannot be perfectly known by the central node in time-varying underwater acoustic (UWA) channels, due to the long propagation delays resulting from the low sound speed. In this paper, we explore the CSI feedback for resource allocation. An adaptive power-bit loading algorithm is presented, which assigns subcarriers to different users and allocates power and bits to each subcarrier, aiming to minimize the bit error rate (BER) under power and throughput constraints. Simulation results show considerable performance gains due to adaptive subcarrier allocation and further improvement through power and bit loading, as compared to the non-adaptive interleave subcarrier allocation scheme. In a lake experiment, channel feedback reduction is implemented through subcarrier clustering and uniform quantization. Although the performance gains are not as large as expected, experiment results confirm that adaptive subcarrier allocation schemes based on delayed channel feedback or long term statistics outperform the interleave subcarrier allocation scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12C
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• pp.1021-1028
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• 2008

In a network environment, when a user requests a server's service, a remote user authentication system using smart cards is a very practical solution to validate the eligibility of a user and provide secure communication. In these authentication schemes, due to fast progress of networks and information technology, most of provided services are in multi-server environments. However, there are no studies in multi-server authentication schemes using smart cards providing mutual anonymity so far. In this paper, we propose a novel user authentication scheme using smart cards providing mutual authentication and mutual anonymity for multi-server environments. Our proposed scheme achieves the low-computation requirement for smart cards and a user can use permitted various services in eligible servers by only one registration. Also, this scheme guarantees perfect mutual anonymity of participants.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1663-1668
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• 2005

There have been numerous researches regarding the QoS guarantee in packet switching networks. IntServs, based on a signaling mechanism and scheduling algorithms, suggesting promising solutions, yet has the crucial complexity problem so that not enough real implementations has been witnessed. Flow aggregation is suggested recently to overcome this issue. In order to aggregated flows fairly so that the latency of the aggregated flows is bound, however, a non-work conserving scheduler is necessary, which is not very popular because of its another inherent complexity. We suggest a non-work conserving scheduler, the Round Robin with Virtual Flow (RRVF), which is a variation of the popular Deficit Round Robin (DRR). We study the latency of the RRVF, and observe that the non-work conserving nature of the RRVF yields a slight disadvantage in terms of the latency, but after the aggregation the latency is greatly reduced, so that e combined latency is reduced. We conclude that the flow aggregation through RRVF can actually reduce the complexity of the bandwidth allocation as well as the overall latency within a network.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.1
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• pp.3-9
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• 1999

This study is focused on the developing of the telecommunication technique for the analysis on the social changes. In the scope and method of this study there must invalve following three items; change living environment, solution of medical problom, solution of education problem. The results of this study is as follow: First, telecommunication technique policy must be constructed in Korea. Second, digitalizing interchange machine and wire network must be promoted, presenting the development and establishment direction of B-ISDN. Third, the telecommunication policy in future must be able to unify all the networks.