• The KIPS Transactions:PartA
• /
• v.11A no.7 s.91
• /
• pp.511-520
• /
• 2004

A peer-to-peer model is very useful in solving the server link bottleneck problem of a client-server model. In this work, we discuss the problems of distributing multimedia content over peer-to-peer network. We focus on two problems in peer-to-peer media content distribution systems. The first is the transmission scheduling of the media data for a multi-source streaming session. We present a sophisticated scheduling scheme called fixed-length slotted scheduling, which results in minimum buffering delay. The second problem is on the fast distribution of media content in the peer-to-peer system that is self-growing. We propose a mechanism accelerating the speed at which the system's streaming ca-pacity increases, called FAST.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2010.07a
• /
• pp.360-363
• /
• 2010

Streaming Technology can support the real-time playback without downloading and storing multimedia data in local HDD. So, client browser or plug-in can represent multimedia data before the end of file transmission using streaming technology. Recently, the demand for efficient real-time playback and transmission of large amounts of multimedia data is growing rapidly. But most users' connections over network are not fast and stable enough to download large chunks of multimedia data. In this paper, we propose an intelligent IP streaming system based on personalized media service. The proposed IP streaming system enables users to get an intelligent recommendation of multimedia contents based on the user preference information stored on the streaming server or the home media server. The supposed intelligent IP streaming system consists of Server Metadata Agent, Pumping Server, Contents Storage Server, Client Metadata Agent and Streaming Player. And in order to implement the personalized media service, the user information, user preference information and client device information are managed under database concept. Moreover, users are assured of seamless access of streamed content event if they switch to another client device by implementing streaming system based on user identification and device information. We evaluate our approach with manufacturing home server system and simulation results.

• Journal of ILASS-Korea
• /
• v.12 no.2
• /
• pp.86-93
• /
• 2007

There is a growing interest to develop an eco-friendly air cleaner with high performance through a remanufacturing process. Two kinds of polyurethane filter media, a coarse (Filter-A) and a fine filter media (Filer-B), are used in this study to protect a vehicle engine from airborne particles. In order to improve the collection performance of the filters (Filter-A, Filter-B), an oil coating technology on the filter surface was introduced. As a result, inertial force is a dominant collection mechanism for a dry filter media, so that collection efficiency increases with increasing filtration velocity. However, intra-structure change of an oil-coated filter media influences on the collection mechanism, which shows a non-linear collection efficiency curve in terms of filtration velocity. The result shows that the developed filter media are eco-friendly and effective to protect a vehicle engine from airborne particles especially at low filtration velocity.

• Journal of the Korean Academic Society of Industrial Cluster
• /
• v.4 no.1
• /
• pp.51-61
• /
• 2010

Digital Signage is outdoor media to provide each content and message through digital displays instead that posters and signs are displayed on public facilities. Recently, digital signage have been popular to deliver variety information and advertising on the rapid development of intelligent digital imaging devices based LCD, LED. Continuously digital signage demand and market are growing because digital signage feature is able to capable of interactive communication. Digital signage is expected that digital advertising market is continue rising in spite of global economic downturn at various research institutions, and it is expected to replace traditional media advertising in a new way with the coming digital signage at convergence media side.

• The Research Journal of the Costume Culture
• /
• v.25 no.6
• /
• pp.928-942
• /
• 2017

Social media has become an integral part of consumers' daily lives. Individuals connect with one another on social networking sites to like, share, and post information and experiences. As social media become popular among millennials, a growing number of fashion retailers use social media networks in the context of online commerce transactions. Accordingly, an increased number of fashion retailers has been using social media as an advertising tool and a retail channel. Despite the popularity of social media among millennials, empirical findings are limited to reveal factors associated with young consumers' intentions to use social commerce in fashion shopping. This study sought to examine factors affecting millennials' intentions to use social commerce in fashion shopping by adopting the technology acceptance model. A total of 524 college students completed an online survey in the U.S. The results of structural equation model confirmed that perceived ease of use, usefulness, and enjoyment had a positive impact on millennials' attitudes and intentions toward fashion shopping in social commerce. While both perceived ease of use and usefulness positively influenced enjoyment, usefulness had a stronger impact than ease of use. Compared to usefulness, enjoyment had much stronger impact on attitudes. Further structural model analysis revealed a direct, positive influence of perceived usefulness of social commerce on perceived enjoyment of social commerce, which has not been explored in prior studies. These findings provide theoretical and managerial implications.

• Journal of Digital Contents Society
• /
• v.18 no.8
• /
• pp.1523-1527
• /
• 2017

Recently, there have been a growing number of services for users to shoot content by themselves and to broadcast this data to a large number through the Internet. One-person media live services are popular in life, and similar services are becoming common. Most of these services are for general users. However, depending on the service model or the situation, there are cases where the object of streaming is limited depending on the security-sensitive service environment. Especially, in the case of closed networks such as military, government, and security organizations, these specialized services are needed. Therefore, in this paper, we implemented a live media system in a closed network environment. We study system components suitable for service environment and study how to develop components.

• Microbiology and Biotechnology Letters
• /
• v.35 no.1
• /
• pp.73-80
• /
• 2007

Biofilm media was equipped in two-compartmented wastewater treatment bioreactor which was separated by porcelain septum. DC 2.0 volt of electric potential was charged to anodic (oxidative) biofilm media (ABM) to induce oxidation potential but not to that of carbon (neutral) biofilm media (CBM) that was used for control test. Biofilm structure, biomass variation, Off variation and wastewater treatment efficiency in the bioreactor equipped with ABM (ABM-bioreactor) and CBM (CBM-bioreactor). Time-coursed variation of biofilm structure forming on surface of ABM and CBM was observed by scanning electron microscopy. The biofilm growing on ABM was dispersed on surface and was not completely covered the media but the biofilm growing on CBM was continuously increased and finally covered the media. The ORP of CBM was decreased to 100 mV, which was reciprocally proportional to the biomass growth. However, the ORP of ABM was about 800 mV, which was maintained during operation for about 60 days. The treatment efficiency of COD in the ABM bioreactor was 2 times higher than those in the CBM bioreactor. From these results, we proposed that electrochemical oxidation potential charged to biofilm media may inhibit formation of biofilm extremely condensed and activate bacterial cell metabolism.

• Journal of the Korea Convergence Society
• /
• v.11 no.2
• /
• pp.109-116
• /
• 2020

Social media is growing rapidly as a means of promoting artists' artworks and a channel for sales. However, since social media is not fundamentally a platform designed for trading, it has various limitations that make it difficult to ensure trust and security in carrying out transactions. In this paper, it is proposed interoperability between social media and blockchain-based smart contract system that can record and preserve the artist's profile, information related to artworks and details of the contract on the blockchain. The proposed interoperability allows artwork trading participants on social media to maintain mutual trust and to conduct the contract transparently. Also, the proposed interoperability consists of an API provided by the social media developer or an open source API without having to modify existing social media. This study is expected to contribute to the growth of the art trading market on social media by complementing the art trading practices on social media.

• Horticultural Science & Technology
• /
• v.28 no.6
• /
• pp.973-979
• /
• 2010

The objective of this study was to determine the effect of electrical conductivity (EC) of nutrient solution on the growth, nutrient uptake of potted kalanchoe plants ($Kalanchoe$ $blossfeldiana$ 'New Alter') and the nutrient accumulation at the growing media with growth stage in ebb and flow subirrigation systems. Significant differences in leaf area, plant height, and dry weight of the plants were found among the different ECs of nutrient solution of 0.8, 1.6, 2.4, and $3.2dS{\cdot}m^{-1}$. Particularly the difference in plant growth became significantly greater from 5 weeks after treatment. The overall growth was the highest at EC $1.6dS{\cdot}m^{-1}$. Leaf area, plant height, and dry weight were maintained higher when EC increased to $2.4dS{\cdot}m^{-1}$, but rapidly decreased after EC $3.2dS{\cdot}m^{-1}$. The uptake of NO3-N was the greatest while that of $Mg^{2+}$ was the lowest at EC $1.6dS{\cdot}m^{-1}$, even though small differences were found among macro elements. The EC at the top layer of the growing media was 1 to 3 times higher than that at the bottom layer. Nutrient accumulation was accelerated in both the top and bottom layers with growth stage. At EC $3.2dS{\cdot}m^{-1}$, the growth of the plants was suppressed due to higher nutrient accumulation at the growing media. From the results, the strength and composition of nutrient solution should be determined by considering nutrient accumulation at the growing media in addition to EC of nutrient solution in ebb and flow subirrigation systems.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.29 no.1
• /
• pp.19-27
• /
• 2021

Hydroponic farming is a method to grow a plant without soil. Plants can be grown on water or hydroponic growing media, and they are fed with mineral nutrient solutions, which are fertilizers dissolved into water. Hydroponic farming has the advantage of increasing plant productivity over conventional greenhouse farming. Previous studies of hydroponic nutrient wastewater from acyclic hydroponic farms pointed out that hydroponic nutrient wastewater contained residual nutrients, and they were drained to a nearby river bank which causes several environmental issues. Also, previous studies suggest that excessive use of the nutrient solution and disposal of used hydroponic growing media and crop wastes in hydroponic farms are major problems to hydroponic farming. This study was conducted to determine the impact of hydroponic nutrient wastewater, used hydroponic growing media, and crop wastes from acyclic hydroponic farms on the surrounding environment by analyzing water quality and soil analysis of the above three factors. Three soil cultivation farms and several hydroponic farms in the Gangwon C region were selected for this study. Samples of water and soils were collected from both inside and outside of each farm. Also, a sample of soil and leachate from crop waste piles stacked near the farm was collected for analysis. Hydroponic nutrient wastewater from acyclic hydroponic farm contained an average of 402 mg/L of total nitrogen (TN) concentration, and 77.4 mg/L of total phosphate (TP) concentration. The result of TP in hydroponic nutrient wastewater exceeds the living environmental standard of the river in enforcement decree of the framework act on environmental policy by 993.7 times. Also, it exceeds the standard of industrial wastewater discharge standards under the water environment conservation act by 6~19 times in TN, and 2~27 times in TP. Leachate from crop waste piles contained 11,828 times higher COD and 395~2662 times higher TP than the standard set by the living environmental standard of the river in enforcement decree of the framework act on environmental policy and exceeds 778 times higher TN and 5 times higher TP than the standard of industrial wastewater discharge standards under the water environment conservation act. For more precise studies of the impact of hydroponic nutrient wastewater, used hydroponic growing media, and crop wastes from acyclic hydroponic farms on the surrounding environment, additional information regarding a number of hydroponic farms, arable area(ha), hydroponic farming area, seasonal, weather, climate factor around the river, and the property of the area and farm is needed. Analysis of these factors and additional water and soil samples are needed for future studies.