• Journal of Communications and Networks
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• v.8 no.4
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• pp.410-421
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• 2006

In this work, we propose an analytic framework for dimensioning the link capacity of broadband access networks which provide universal broadband access services to a diverse kind of customers such as patient and impatient customers. The proposed framework takes into account the flow-level quality of service (QoS) of a connection as well as the packet-level QoS, via which a simple and systematic provisioning and operation of the network are provided. To that purpose, we first discuss the necessity of flow-aware network dimensioning by reviewing the networking technologies of the current and future access network. Next, we propose an analytic model for dimensioning the link capacity for an access node of broadband convergence networks which takes into account both the flow and packet level QoS requirements. By carrying out extensive numerical experiment for the proposed model assuming typical parameters that represent real network environment, the validity of the proposed method is assessed.

• Journal of Korea Multimedia Society
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• v.17 no.2
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• pp.180-190
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• 2014

Social network services are increasingly being used in organizational settings to improve relationships among employees and enhance prospects for information exchange and cooperative work. Social Networking Service(SNS) has deeply penetrated organizational job settings, influencing multiple aspects of employee's life. This study is designed to explore the impact of SNS engagement on the job performance mediated as team cooperation and decision making quality effects. Data were collected from 146 employees who use organizational SNS in there company. Factor analysis and structural equation method are employed. Results from a survey accompanied by the substantial impacts of organizational employee's social networking engagement on social learning processes and outcomes. SNS engagement not only directly influences organizational employee's job performance, but also helps their team cooperation and decision making quality from others and adapt to organizational culture, both of which play prominent roles in improving their job performance.

• ETRI Journal
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• v.46 no.5
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• pp.915-927
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• 2024

We obtain the air quality index (AQI) for a descriptive system aimed to communicate pollution risks to the population. The AQI is calculated based on major air pollutants including O₃, CO, SO₂, NO, NO₂, benzene, and particulate matter PM2.5 that should be continuously balanced in clean air. Air pollution is a major limitation for urbanization and population growth in developing countries. Hence, automated AQI prediction by a deep learning method applied to time series may be advantageous. We use a seasonal autoregressive integrated moving average (SARIMA) model for predicting values reflecting past trends considered as seasonal patterns. In addition, a transductive long short-term memory (TLSTM) model learns dependencies through recurring memory blocks, thus learning long-term dependencies for AQI prediction. Further, the TLSTM increases the accuracy close to test points, which constitute a validation group. AQI prediction results confirm that the proposed SARIMA-TLSTM model achieves a higher accuracy (93%) than an existing convolutional neural network (87.98%), least absolute shrinkage and selection operator model (78%), and generative adversarial network (89.4%).

• Journal of Korean Academy of Nursing
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• v.47 no.4
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• pp.476-487
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• 2017

Purpose: This study aimed to examine the effects of cognitive behavior therapy for insomnia (CBT-I) based on the mobile social networking service (SNS) on dysfunctional beliefs and attitudes about sleep, sleep quality, daytime sleepiness, depression, and quality of life among rotatingshift nurses in a hospital in Korea. Methods: A nonequivalent control group pre-post test design was used. The participants included 55 nurses with rotating three-shift work (25 in the experimental group and 30 in the control group). For the experimental group, CBT-I using mobile SNS was provided once a week for 60 minutes over six weeks. Data were analyzed using descriptive statistics, $x^2-test$, independent samples t-test, and Mann-whitney U test with the SPSS 21.0 program. Results: In the homogeneity test of the general characteristics and study variables, there were no significant differences between the two groups. Nurses in the experimental group had significantly lower scores on dysfunctional beliefs and attitudes regarding sleep and sleepiness than nurses in the control group. Nurses in the experimental group had significantly higher scores on sleep quality and quality of life than nurses in the control group. Conclusion: These findings indicate that using the mobile SNS-based CBT-I is feasible and has significant and positive treatment-related effects on rotating-shift nurses' irrational thoughts and beliefs in association with sleep, sleep quality, daytime sleepiness, and quality of life. These contribute to expanding our knowledge of rotating-shift nurses' sleep issues and their preferences for intervention.

• Smart Media Journal
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• v.8 no.2
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• pp.29-38
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• 2019

With the advancement of information and communication technology, tactical networks are continuously being converted to All-IP future tactical networks that integrate all application services based on Internet protocol. Futuristic tactical mesh network is built with tactical WAN (wide area network) nodes that are inter-connected by a mesh structure. In order to guarantee QoS (quality of service) of application services, tactical service mesh (TSM) is suggested as an intermediate layer between infrastructure and application layers for futuristic tactical mesh network. The tactical service mesh requires dynamic QoS monitoring and control for intelligent QoS coordination. However, legacy networking nodes used for existing tactical networks are difficult to support these functionality due to inflexible monitoring support. In order to resolve such matter, we propose a tactical mesh WAN node as a hardware/software co-designed networking node in this paper. The tactical mesh WAN node is conceptually designed to have multi-access networking interfaces and virtualized networking switches by leveraging the DANOS whitebox server/switch. In addition, we explain how to apply eBPF-based traffic monitoring to the tactical mesh WAN node and verify the traffic monitoring feasibility for supporting QoS coordination of tactical-mesh traffic.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.10
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• pp.1018-1023
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• 2010

The CAN (Controller Area Network) system is the most dominant protocol for in-vehicle networking system because it provides bounded transmission delay among ECUs (Electronic Control Units) at data rates between 125Kbps and 1Mbps. And, many automotive companies have chosen the CAN protocol for their in-vehicle networking system such as chassis network system because of its excellent communication characteristics. However, the increasing number of ECUs and the need for more intelligent functions such as ADASs (Advanced Driver Assistance Systems) or IVISs (In-Vehicle Information Systems) require a network with more network capacity and the real-time QoS (Quality-of-Service). As one approach to enhancing the network capacity of a CAN system, this paper introduces a CAN system with dual communication channel. And, this paper presents a distributed message allocation method that allocates messages to the more appropriate channel using forecast traffic of each channel. Finally, an experimental testbed using commercial off-the-shelf microcontrollers with two CAN protocol controllers was used to demonstrate the feasibility of the CAN system with dual communication channel using the distributed message allocation method.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.4
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• pp.197-203
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• 2020

This study investigates graduate competencies that can improve the uptake of higher education graduate outcomes in the working environment in Indonesia. This research was conducted by collecting data through sending questionnaires directly by the research team, via courier, or via postal service to respondents. A survey with questionnaire is carried out on April 2019, and the data from 117 respondents was analyzed. The sample population was all private higher education in the area of the I-XIV Higher Education Service Institution in Indonesia. This study employs factor analysis and structural equation modelling. The results show that the Graduates' competencies had a significant direct effect on the uptake of higher education graduates in the job market. The indirect effect of a Diploma Supplement and networking as mediation has a level of influence that is higher than the direct effect of graduate competence on the uptake of higher education graduate outcomes in the job market. The findings suggest that the Diploma Supplement and networking can increase the uptake of higher education graduates in Indonesia as expected by stakeholders and be able to compete in the global or international scale of environmental working. The professionalism of lecturers has a significant influence on the quality of learning.

• Journal of Ubiquitous Convergence Technology
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• v.2 no.1
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• pp.51-55
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• 2008

A digital home is a ubiquitous environment that is expected to be realized in the near future. All information appliances in a house are connected to each other through wired and/or wireless home networks. Authenticated user can access the various services provided by the digital home, and the access is not restricted by equipment, time, or location. The technologies that form the digital home can be grouped into two categories: wired networking technologies and wireless networking technologies. For the purpose of ubiquitous environments, wireless-networks offer suitable and seamless high-quality services. A wireless LAN can be created simply by equipping a single access point. For that reason, the cost of establishing such a network is low and using it is easy. Of course, there is an exciting new wireless technology. It is the Ultra Wide Band (UWB). However, it is not enough to bring wireless convenience, although offering a broad range of high-speed data transfer capabilities, Because of unstable. Thus, of the wireless-networking systems, we focus on the wireless LAN. We quantitatively analyze its capabilities. The dynamic and adaptive wireless LAN provides a foundation for the evolution toward the next generation of wireless and adaptive networks. The difference between wired LAN and wireless LAN in upload and download rates is small. Although the wireless LAN experiences a greater loss rate than the wired LAN, the difference is minimal. We conclude that a wireless LAN is suitable for use in an apartment environment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.10
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• pp.2430-2447
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• 2013

In recent years, HTTP adaptive streaming (HAS) has attracted considerable attention as the state-of-the-art technology for video transport. HAS dynamically adjusts the quality of video streaming according to the network bandwidth and device capability of users. Content-Centric Networking (CCN) has also emerged as a future Internet architecture, which is a novel communication paradigm that integrates content delivery as a native network primitive. These trends have led to the new research issue of harmonizing HAS with the in-network caching provided by CCN routers. Previous research has shown that the performance of HAS can be improved by using the H.264/SVC(scalable video codec) in the in-network caching environments. However, the previous study did not address the misbehavior that causes video freeze when overestimating the available network bandwidth, which is attributable to the high cache hit rate. Thus, we propose a new SVC-based adaptation algorithm that utilizes a drop timer. Our approach aims to stop the downloading of additional enhancement layers that are not cached in the local CCN routers in a timely manner, thereby preventing excessive consumption of the video buffer. We implemented our algorithm in the SVC-HAS client and deployed a testbed that could run Smooth-Streaming, which is one of the most popular HAS solutions, over CCNx, which is the reference implementation of CCN. Our experimental results showed that the proposed scheme (SLA) could avoid video freeze in an effective manner, but without reducing the high hit rate on the CCN routers or affecting the high video quality on the SVC-HAS client.

• Journal of Communications and Networks
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• v.8 no.2
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• pp.234-240
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• 2006

We study the dynamic burst assembly based on traffic prediction and offset and delay differentiation in optical burst switching network. To improve existing burst assembly mechanism and build an adaptive flexible optical burst switching network, an approach called quality of service (QoS) based adaptive dynamic assembly (QADA) is proposed in this paper. QADA method takes into account current arrival traffic in prediction time adequately and performs adaptive dynamic assembly in limited burst assembly time (BAT) range. By the simulation of burst length error, the QADA method is proved better than the existing method and can achieve the small enough predictive error for real scenarios. Then the different dynamic ranges of BAT for four traffic classes are introduced to make delay differentiation. According to the limitation of BAT range, the burst assembly is classified into one-dimension limit and two-dimension limit. We draw a comparison between one-dimension and two-dimension limit with different prediction time under QoS based offset time and find that the one-dimensional approach offers better network performance, while the two-dimensional approach provides strict inter-class differentiation. Furthermore, the final simulation results in our network condition show that QADA can execute adaptive flexible burst assembly with dynamic BAT and achieve a latency reduction, delay fairness, and offset time QoS guarantee for different traffic classes.