• Journal of Broadcast Engineering
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• v.19 no.1
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• pp.14-23
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• 2014

This paper proposed controlling methods for SDN(Software Defined Network) based multiple radio access technology as the solutions of following two issues which were mainly occurred by explosive increasing of video traffic. The first one is a requirement for traffic off-loading caused by 3rd-party video service providers from the mobile network operator's viewpoint. The other one is a provision of high-speed video contents transmission services with low price. Furthermore, the performance evaluation was also conducted on the real test-bed which is composed of OpenStack cloud and SDN technology such as OpenFlow and Open vSwitch. A virtual machine running on the OpenStack provide a video service and the terminal which is able to use multiple radio access technology supports two 2.4GHz WLANs(Wireless Local Area Network) and three 5GHz WLANs, concurrently. Finally, we can get 820Mbps of the maximum transmission speed by using that five WLAN links for the single service at the same time.

• The Transactions of the Korea Information Processing Society
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• v.4 no.8
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• pp.2080-2091
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• 1997

It is generally recognized that Video On Demand (VOD) service will become a promising interactive service in the emerging broadband integrated services digital networks. A centralized VOD system, all programs are stored in a single VOD server which is linked to each user via exchanges, is applicable when a small number of users enjoys the VOD service. However, in case of large service penetration, it is very important to solve the problems of bandwidth and load concentrating in the central video server(CVS) and program transmission network. In this paper, the architecture of the video distribution service network is studied, then a traffic characteristics and models for VOD system are established, and proposed program allocation method to video servers. For this purpose, we present an analysis of program storage amount in each LVS(Local Video Server), transmission traffic volume between LVSs, and link traffic volume between CVS and LVSs, according to changing the related factors such as demand, the number of LVS, vision probability, etc. A method for finding out storage capacity in LVSs is also presented on the basis of the tradeoffs among program storage cost, link traffic cost, and transmission cost.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.1
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• pp.103-116
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• 2022

The purpose of this study is to investigate the perception on video material making and the effect on science teaching ability after conducting non-face-to-face teaching material making activity for elementary pre-service teachers. This activity consisted two processes. One is that elementary pre-service teachers conduct inquiry, understand related science concepts, analyze science textbooks and then make video material. The other is that they watch video materials produced by colleagues. This study was conducted on 89 elementary pre-service teachers for 8 weeks. After this activity was completed, the perception on video material making and the effect on science teaching ability of elementary pre-service teachers were investigated, and the results were analyzed. In the process of making and watching non-face-to-face teaching materials, elementary pre-service teachers showed positive results in teaching-learning, video production, and emotion and attitude toward video material making. In addition, it was found that they improved their science teaching ability through this activity and were very satisfied with this activity. However, they also mentioned several disappointments such as exclusion of learners' right to self-determination, lack of various communication channels, and errors in content of materials. This suggests that if these problems are solved, non-face-to-face classes can also be a good form of class.

• Journal of the Korean Society of Food Culture
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• v.35 no.2
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• pp.181-192
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• 2020

This study aimed to identify whether or not four service situations varying according to positive and negative combinations of physical evidence and functional service influence store image and purchase behavioral intentions of customers at bulgogi restaurants. The video-scenario technique was used for the study. Data were analyzed with the SPSS (Window 19.0) package using frequency analysis, one-way ANOVA, 2 by 2 factorial ANOVA, exploratory factor analysis, and multiple regression analysis to confirm the hypotheses. The combined effect of functional service and physical evidence influenced store image and purchase intention. In terms of seperate effect of physical evidence and functional service, the effect of employee service on store image was more powerful than that of physical evidence, even though the effect differed depending on the situation. Purchase intention was only influenced by functional service quality from employees under the four different scenarios. Thus, when opening a Korean restaurant, proper management of tangible evidence suitable to service, and the prices expected from local customers should be determined. Additionally, extremely high or low levels of physical evidence management should be avoided.

• Journal of Communications and Networks
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• v.7 no.3
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• pp.235-242
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• 2005

Multimedia applications and especially encoded video services, are expected to playa major role in the 3rd generation (3G) and beyond mobile communication systems. Given that future service providers are expected to provide video applications at various price and quality levels, quick and economically affordable methods for preparing/encoding the offering media at various qualities are necessary to be developed. This paper presents a method for objective evaluation of the perceived quality of MPEG­4 video content, based on a quantification of subjective assessments. Showing that subjectively derived perceived quality of service (PQoS) vs. bit rate curves can be successfully approximated by a group of exponential functions, the proposed method exploits a simple objective metric, which is obtained from the mean frame rate vs. bit rate curves of an encoded clip. The validity of this metric is assessed by comparing subjectively derived PQoS results to the corresponding ones, which come from the proposed objective method, showing that the proposed technique provides satisfactory PQoS estimation.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.2
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• pp.60-64
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• 2006

In typical video streaming services such as MPEG encoded video, the transmission data sizes change depending on the frame types and the required bandwidth for QoS support also changes as time passes. Accordingly, in video streaming services using the Internet it could happen that the video services stop occasionally due to instantaneous deficiencies of the required bandwidth under unexpected congestion even if the highest priority is allocated to the service by network administration. In this paper, we investigate several methods for bandwidth allocation and traffic engineering to support MPEG video traffic and propose a new method to reduce the transmission delay and enhance the throughput, there by provisioning the QoS requirements. In the proposed scheme, LSPs are established based on temporal variation patterns of the Internet traffic and the CQ_LLQ policing scheme is applied for traffic shaping at the ingress routers. Finally we verified the performance of the proposed scheme via computer simulations using OPNET.

• Asia-Pacific Journal of Business
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• v.12 no.2
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• pp.205-222
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• 2021

Purpose - Due to the Covic-19 pandemic, the perceived value of video conferencing platforms has been increased drastically. However, there is little guidance on how service providers can improve video conferencing platforms. The purpose of this study is to investigate the factors that influence the users' perceived value of video conferencing services based on the heuristic-systematic model and the value-based adoption model. Design/Methodology/Approach - In this paper, we theoretically explore the relationship of the antecedents of perceived value(credibility, expertise, attractiveness, economic feasibility, security, and interactivity) and its outcomes (perceived usefulness, perceived risk and perceived value). The outcomes of this research is a conceptualization of antecedents of perceived value supported by research hypothesis based on the existing literature. A total of 100 valid questionnaires were collected to empirically test the research model. Findings - The analysis results showed that credibility, economic feasibility, and interactivity positively influenced perceived usefulness. On the other hand, credibility, professionalism and interactivity negatively influenced perceived risk. Perceived usefulness positively affects perceived value and perceived risk has a negative effect on perceived value. The brand image as a moderating variable was found to decrease the effect of perceived risk on perceived value. Research Implications - The contribution of this study is significant for video conferencing providers as follows. First, a service provider can actively utilize influencers or referees with high credibility and expertise to maximize the perceived usefulness of users. Second, economic feasibility should be ensured in respect of users through various alliance discount strategies. Third, a video conferencing service company needs to build a positive brand image in order to increase users' perceived value.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.281-283
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• 2021

The representative companies mentioned in the recommendation service in the domestic OTT(Over-the-top media service) market are YouTube and Netflix. YouTube, through various methods, started personalized recommendations in earnest by introducing an algorithm to machine learning that records and uses users' viewing time from 2016. Netflix categorizes users by collecting information such as the user's selected video, viewing time zone, and video viewing device, and groups people with similar viewing patterns into the same group. It records and uses the information collected from the user and the tag information attached to the video. In this paper, we propose a method to improve video media recommendation by automatically generating metadata of video media that was written by hand.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.5
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• pp.24-32
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• 2011

According to accelerate the convergence of defense and information technology, there is a need for innovative change in Military e-Learning service system. In other words, It has increased the need for system integration based on standards and interoperability to develop into a network-centric information and knowledge. In this study, It would like to introduce an integrated direction Military e-Learning service system on the SOA-based video content services in the operating system for the operating model. SOA is taking advantage in integration and expansion of the unit with a process. Using it, define of video services platform architecture and define of business model based on the Imprimatur model. Based on this, it define the role of actors for video content service in each step of the operating model, that is Production model, Brokerage model and consumption model. In the operating system, it define the functions and data to control and handle the needed functionality for video content services based on the operational model.

• Journal of Digital Convergence
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• v.18 no.3
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• pp.311-316
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• 2020

is a mobile application based SNS video platform that launched its service in China in 2016. At the beginning of the service, TikTok is a music video content platform, and later, it evolved into a social platform that provides a wide variety of contents, and the process of creating, producing, and editing videos was easily provided. Since started its service, it has analyzed various social phenomena that have appeared to young people and the types and characteristics of video content popular in this app. The demand for vertical video content in the form of short clip is on the rise rapidly, which can be expected to improve the quality of video content in accordance with the development of mobile-based imaging technology. Useful for mobile based on the creative video producers through this study data are to be used to.