• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.9B
• /
• pp.793-805
• /
• 2003

In OBS (Optical Burst Switching) networks which decouple the burst from its header, the fault of a fiber link can lead to the failure of all the light-path that traverses the fiber. Because each light-path is expected to operate at a rate of a few Gbps by using WDM (Wavelength Division Multiplexing) technology, any failure may lead to large data loss. Therefore, an efficient recovery scheme must be provided. In this paper, we analyze network utilization and BCP (Burst Control Packet) loss rate according to each link failure by applying the conventional restoration schemes in OBS networks. And through these simulation results, an ASPR scheme is proposed improve the fault management scheme in terms of recovery time and throughput. Finally, We compare the performance of our proposed scheme with that of the conventional one with respect to burst loss rate, resource utilization and throughput by OPNET simulations.

• Journal of Broadcast Engineering
• /
• v.23 no.6
• /
• pp.813-823
• /
• 2018

UHD content is characterized by higher bandwidth requirements to provide seamless playback. The existing HTTP adaptive streaming scheme periodically requests video segment of lower quality than the available bandwidth in the steady state. In the steady state, the On-Off pattern is repeated due to the difference of the available bandwidth and the encoding rate of the content. And the repeated Off interval is causing the problem that can not efficiently use the available bandwidth. In the wireless environment where the delay and loss rate are higher with large bandwidth fluctuations, this problem is exacerbated because the available bandwidth is estimated inaccurately. Therefore, in this paper, we propose a segment scheduling scheme for efficient bandwidth utilization of UHD contents streaming in wireless environment. Proposed scheme is a group segment that simultaneously reqeusts multiple segments in one request message in order to reduce frequency of OFF interval. Through simulation, Our scheme improves bandwidth utilization.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.10a
• /
• pp.527-530
• /
• 2014

DASH is a well-known streaming technology, which was proposed in 2010 by MPEG and standardized in 2011. Major multimedia contents service providers, including Apple, Microsoft, and Adobe are all using this technology to support their media streaming services. Whenever a new service is requested to the server, the DASH technology helps servicing the multimedia streaming to client by recognizing the capacity of network and by adapting the quality of the multimedia contents. In DASH, the quality of multimedia contents will be automatically lowered to meet the fluctuating network status, when undesirable breaks interrupt the network. In this paper, we classified and analysed the advantages and disadvantages of DASH researches in three aspects: bit-rate measurement method, bandwidth aggregation method; rate adaptation metrics, algorithms and logics; user's experiences and QoE.

• Journal of Broadcast Engineering
• /
• v.28 no.2
• /
• pp.185-193
• /
• 2023

As many different over-the-top (OTT) services become ubiquitous, demands for high-quality content are increasing. However, high dynamic range (HDR) contents, which can provide more realistic scenes, are still insufficient. In this regard, we propose a new HDR video reconstruction technique using multi-exposure low dynamic range (LDR) videos. First, we align a reference and its neighboring frames to compensate for motions between them. In the alignment stage, we perform content-based alignment to improve accuracy, and we also present a high-resolution (HR) module to enhance details. Then, we merge the aligned features to generate a final HDR frame. Experimental results demonstrate that our method outperforms existing methods.

• Journal of KIISE:Information Networking
• /
• v.28 no.4
• /
• pp.527-539
• /
• 2001

The wireless asynchronous transfer mode (ATM) system has the advantage of providing the broadband services with various quality-of-service requirements to the mobile terminal efficiently by utilizing the ATM technology developed for the wired ATM system. The available bit rate (ABR) service among various ATM services utilizes the available bandwidth remaining in the ATM link, which allows the efficient bandwidth usage. During the handoff of the mobile terminal, however, the queue length in the access point (AP) which resides in the boundary of the wired ATM network and the wireless ATM network may increase abruptly. In this paper, we propose a scheme which prevents the buffer-overflow and buffer-underflow in the AP during the handoff of the wireless ABR connection in the wireless ATM system using binary feedback rate-based ABR traffic control. This scheme controls the source's cell generation rate during both handoff period and some time interval after the completion of the handoff procedure. The simulation results show that the proposed scheme prevents the buffer-overflow and buffer-underflow. The proposed scheme can contribute to increasing the throughput of the wireless ABR service during handoff by preventing the buffer overflow and underflow during handoff period.

• The Journal of the Korea Contents Association
• /
• v.12 no.7
• /
• pp.323-335
• /
• 2012

The purpose of this study is to clarify the impact of information contents at online purchase sites of movie merchandise. The results of this study are as follows: 1) Movie-understanding information(synopsis, actors, reviews) has a meaningful influence on information service satisfaction irrespective of consumer involvement; 2) Movie-understanding and movie-going information(time, place, price, purchasing method) are alike in having a meaningful influence on online purchasing intention. However, movie-going information has a meaningful influence in case of lower consumer involvement, while movie-understanding information has a meaningful influence in case of higher consumer involvement.; 3) Information service satisfaction gives a strong influence on online purchasing intention irrespective of the level of consumer involvement. In conclusion, there is a need to improve diversity and quality of movie-understanding information to enhance consumer satisfaction. Also, it will be necessary to improve movie-understanding and movie-going information in order to enhance online purchasing intention. These results are expected to give an insight to build a creative marketing strategy of online purchase sites of movie merchandise.

• The KIPS Transactions:PartC
• /
• v.13C no.4 s.107
• /
• pp.427-434
• /
• 2006

Broadband Convergence Network(BcN) is a critical infrastructure to provide wired-and-wireless high-quality multimedia services by converging communication and broadcasting systems, However, there exist possible danger to spread the damage of an intrusion incident within an individual network to the whole network due to the convergence and newly generated threats according to the advent of various services roaming vertically and horizontally. In order to cope with these new threats, we need to analyze the vulnerabilities of BcN in a system architecture aspect and classify them in a systematic way and to make the results to be utilized in preparing proper countermeasures, In this paper, we propose a new classification of vulnerabilities which has been extended from the ITU-T recommendation X.805, which defines the security related architectural elements. This new classification includes system elements to be protected for each service, possible attack strategies, resulting damage and its criticalness, and effective countermeasures. The new classification method is compared with the existing methods of CVE(Common Vulnerabilities and Exposures) and CERT/CC(Computer Emergency Response Team/Coordination Center), and the result of an application to one of typical services, VoIP(Voice over IP) and the development of vulnerability database and its management software tool are presented in the paper. The consequence of the research presented in the paper is expected to contribute to the integration of security knowledge and to the identification of newly required security techniques.

• KIISE Transactions on Computing Practices
• /
• v.23 no.6
• /
• pp.359-370
• /
• 2017

In overseas-hospital construction, the digital hospital is a trend that is based on the developments of the information and communication technologies, state-of-the-art medical equipment, smart health, and telemedicine. Along with the increasing proportion of IT, this has resulted in the spreading of the concept throughout city-like hospitals and their transformation into digital hospitals. In the hospital-construction business, IT is a key element that will link the modernization of the mechanical, electrical, and equipment systems, construction, and medical equipment for efficiency maximization through integration. The purpose of this study is the analysis of the market-expansion success factors through the construction of a success-story-based, IT-driven overseas-hospital business. The digital-hospital concept and the development process are analyzed through a literature review, and the success factors are analyzed in terms of the cost, time, and quality that are proposed in the project-management body of knowledge. The main contributions of this study regarding the success factors are as follows: First, a cost-side need exists regarding the establishment of strategic-value engineering in terms of increasing the value from the perspectives of the IT and operational infrastructures; second, in terms of the construction time, all of the hospital systems must comply with the established deadlines for the integrated test and commissioning; and lastly, in terms of quality, it is important to ensure that the System Integration digital-hospital services are delivered according to the user requirements.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.11
• /
• pp.2603-2608
• /
• 2015

Mushroom is a high in protein, low calorie food and has dietary fiber, vitamins, iron and minerals such as zinc. It is called that mushroom is one of the biggest concerns for healthy foods. When we make the artificial cultivation of mushroom, one of the greatest influence element is temperature. In this regard, farmers passively measure temperatures in the greenhouse as inaccurate way such as by the naked eyes. In this paper, we constructed a display system in order to improve the efficiency of manual management of temperature based on the influence of temperature on the mushroom. In related to the methods of mushroom cultivation, the recent technology apply the new technology such as sensors and IT convergence services. And then cultivating mushroom is managed effectively. In this paper, we implement an automatic display system for sensing data. By using this function, farmers could effectively manage environment needed to be grown mushroom, and anticipate the improvement of sales by increasing quality of mushrooms as well.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.11
• /
• pp.2597-2602
• /
• 2015

With the development of economy and improving of people's living standards, people dietary needs will be achieved from subsistence to high nutrition and from high nutrition to healthy transformation. Mushroom as a kind of highly nutritious, low fat, rich vitamin food has a great interest among the people. This makes the mushroom into a new sunrise industry and it gradually from pure manual cultivation develops toward the fully automatic factory. In the process of mushroom factory production, regulation of environmental factors directly affects the yield and quality of mushroom. In related to the methods of mushroom cultivation, the recent technologies apply the new technology such as sensors and IT convergence services. And then cultivating mushroom is managed effectively. This paper in order to solve the above problems and construct an effective mushroom growth environment using technology such as humidity sensor construct an environment that can automatically adjust the humidity. This environment has important significance to improve the level of automation mushroom production, increase yield per unit area and quality of mushroom, increase economic efficiency of mushroom production, and enhance the competitiveness of mushroom production.