• International Journal of Computer Science & Network Security
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• v.22 no.2
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• pp.327-333
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• 2022

Internet Protocol Television (IPTV) has emerged as a personal entertainment source for home users. Streaming IPTV content over a wireless medium with good Quality of Service (QoS) can be a challenging task as IPTV content requires more bandwidth and Wireless Local Area Networks (WLANs) are susceptible to packet loss, delay and jitter. This research presents the capacity of IPTV using User Datagram Protocol (UDP) and TCP Friendly Rate Control (TFRC) over IEEE 802.11ac WLANs in good and bad network conditions. Experimental results show that in good network conditions, UDP and TFRC could accommodate a maximum of 78 and 75 Standard Definition Television (SDTV) users, respectively. In contrast, 15 and 11 High-Definition Television (HDTV) users were supported by UDP and TFRC, respectively. Performance of UDP and TFRC was identical in bad network conditions and same number of SDTV and HDTV users were supported by TFRC and UDP. With background Transmission Control Protocol (TCP) traffic, both UDP and TFRC can support nearly the same number of SDTV users. It was found that TFRC can co-exist fairly with TCP by giving more throughput to TCP unlike UDP.

• Journal of the Korea Society for Simulation
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• v.8 no.2
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• pp.45-56
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• 1999

It is necessary that we should control the traffic to not only efficiently use the rich bandwidth of ATM network but also satisfy the users various requirements for service quality. However, it is very difficult to decide which control mechanism would be applied in real network because there are various types of ATM traffic and traffic control mechanisms. In this paper, a smart simulator is developed ot analyze the performance of a UPC(Usage Parameter Control) mechanism which is a typical traffic control mechanism. The simulator consists of a user interface that supports a menu-driven input form and a simulation program that is executed with the users input parameters. Especially, the simulator establishes more powerful and flexible simulation environment since it supports a more complex simulation applying various source traffic to several different UPC mechanisms at the same time and allows an arbitrary user-defined traffic in addition to some well-known traffic.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.2A
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• pp.146-156
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• 2002

This paper presents an adaptive H.263+ rate control algorithm for streaming video applications under the networks supporting bandwidth renegotiation, which can communicate with end-users to accommodate their time-varying bandwidth requests during the data transmission. That is, the requests of end-users can be supported adaptively according to the availability of the network resources, and thus the overall network utilization can be improved simultaneously. They are especially suitable for the transmission of non-stationary video traffics. The proposed rate control algorithm communicates with the network to renegotiate the required bandwidth fort the underlying video which are measured based on the motion change information, and choose their control strategies according to the renegotiation results. Unlike most conventional algorithms that control only the spatial quality by adjusting quantization parameters, the proposed algorithm treats both the spatial and temporal qualities at the same time to enhance human visual perceptual quality. Experimental results are provided to demonstrate that the proposed rate control algorithm can achieve superior performance to the conventional ones with low computational complexity under the networks supporting bandwidth renegotiation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.8
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• pp.1632-1642
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• 1997

In this paper, we studied the effects of the power control imperfection on the system performances of a microcellular DS/CDMA system. The maximum user capacity, defined as the maximum number of users can be serviced simultaneouly, meeting a given voice quality, is first considered. Then the performence degradation due to the control error is analyzed. The frequency selective Raician channel model is used to characterize a microcellular mobile communication environment. The DS/CDMA system under consideration uses BPSK modulation and convolutional coding/Viterbe decoding with soft decision for forward error correction. It is shown that the user capacity falls linearly down with the increase of the power control error(in terms of the standard deviation in dB) and the interference from users outside the third tier cells have a minor effect on the performance. And the performance of DS/CDMA with the imperfect power control model is made to be less than 50% of that with perfect power control moded.

• Asia pacific journal of information systems
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• v.25 no.4
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• pp.719-745
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• 2015

Social networking services provide individuals with an easy approach for exchanging messages with others based on interpersonal relationships. However, why individuals spread marketer-generated content (MGC) in their online social circles remains unclear. Therefore, we develop a theoretical model to examine how social capital, intrinsic motivations, personal perceptions, past behavior, and personal traits influence MGC sharing behavior of social media users in micro-blogging context. Data collected from 319 social networking users support the proposed model. The results from partial least squares analyses show that enjoyment, perceived control, and outcome expectations are significant indicators of individual's MGC sharing intention in the social broadcasting environment. Results also suggest that social capital, users' intention, and past behavior positively influence the MGC sharing behavior of users. Moreover, individual prevention pride exhibits a significant interaction effect on the relationships between users' MGC sharing and its antecedents. Implications for research and practice are discussed.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.163-170
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• 2017

As the usage of smart phones continues to increase, the control UI, which users have to continue to use, sometimes finds a heavy burden on users. Therefore, in this study, we have studied the control user interface structure along with the theoretical background of the control user interface, and we have studied the role and usage of the control component based on it. Typical commonly used controls are button controls for transmission, selection controls for various selections, link controls for navigation, text controls for inputting characters, indicator controls for feedback on progress, A message control that displays information about warnings and errors, and a window control such as a dialog box. The structure of the control should be designed according to the use of the separated control to help the user efficiently use the control user interface. Based on the analysis of the theoretical usage of representative components belonging to the separated controls, we presented a new and correct way to use the control to improve the user experience. The use of improved control components will help to design the control structure efficiently and to improve the user experience.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.3
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• pp.79-87
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• 2019

The system proposed in this paper is a fully automated parking control system that can even protect users' information through blockchain. Unlike conventional parking control systems, the system consists of a web page that is accessible to people of all ages and ages, directly to the parking lot. Such a system would also benefit managers in the parking lot business. This is because it can reduce soaring labor costs and maximize the sales it can generate by operating 24 hours a day. In order to implement these systems, the web page was first designed using HTML and the API was configured using JAX-RS to invoke the API required by the web page. As a result, it created a web page that was easily accessible to anyone, built a server that could be accessed by more than 200 people at the same time, focused on personal information protection by encrypting the information of users through blockchain grafts, and designed a system that enabled users to complete payments easily. It is planning to add QR codes and GPS functions in the future and implement a function that allows one-touch information on parking lots and their vehicle information.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.616-619
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• 2004

As interests Un virtual reality being increased, the importance of HCI(Human computer interaction) field using gesture is also increased. However, in the preceding gesture recognition, the requirement of high-cost peripheral equipments limits users right. In this paper we suggest that through using low cost of USB PC-camera users are allowed to have more flexibly and cost down so that it can be adopted much commonly.

• The KIPS Transactions:PartA
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• v.13A no.7 s.104
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• pp.599-606
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• 2006

As the P2P service does not have any administration authorities that are able to manage the behavior of participants and control the malicious users, malicious user can give harm to legitimate users for the benefit of themselves. To perform the secure transaction with new members who did not have past experiences on transaction, service users can differentiate malicious users and legitimate users by referring to the reputation information that provided by users having past experience. However, users can intentionally give false evaluation to other users on Performed transaction. We call these users as 'liar'. In this Paper, we propose a new reputation system for liar reduction to guarantee an accuracy on reputation information.

• KIISE Transactions on Computing Practices
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• v.23 no.9
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• pp.550-556
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• 2017

Due to the rapid growth and development of Internet of Things (IoT), various devices are now accessible and controllable anytime from anywhere. However, the current IoT system requires a series of complex steps (e.g., launch an application, choose a space and thing, control the thing, etc.) to control the IoT devices; therefore, IoT suffers from a lack of efficient and intuitive methods of interacting with users. To address this problem, we propose a novel IoT control framework based on IoT tags and social messages. The proposed system provides an intuitive and efficient way to control the device based on the device ownership: 1) users can easily control the device by IoT tagging, or 2) users can send an IoT social message to the device owner to request control of the tagged device. Through the development of the prototype system, we show that the proposed system provides an efficient and intuitive way to control devices in the IoT environment.