• Journal of Broadcast Engineering
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• v.10 no.4 s.29
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• pp.548-556
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• 2005

In wireless network environments, wireless channels are characterized by time-varying fading and interference conditions, which may lead to burst packet corruptions and delay variation. This can cause severe quality degradation of streaming media. To guarantee successful transmission of media over the hostile wireless networks, where channel conditions are highly fluctuating, a flexible and network-adaptive transport method is required. Thus, we propose a network-adaptive transport error control consisting of packet-level interleaved FEC and delay-constrained ARQ, which acts as an application-level transport method of streaming media to alleviate burst packet losses while adapting to the changing channel condition in wireless networks. The performances of the proposed network-adaptive transport error control, general error control schemes, and hybrid schemes are evaluated by a developed simulator at the transport-level and video quality of streaming media. Simulation results show that the proposed mechanism provides the best overall performance among compared other schemes in terms of the transport-level performance of error control and the performance of video quality for streaming media.

• Proceedings of the Safety Management and Science Conference
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• 2008.11a
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• pp.57-68
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• 2008

Since six sigma program was first introduced in late 1990's, it has been evolved in Korea. The number of six sigma adopting company are getting increased and diversify manufacturing, service, government. In these days, the rapid innovation of internet technology change the media industry's game rule. This paper is concerned with a six sigma applications to internet media portal service company. The main focus of this study is to introduce an empirical case study on the implementation of DMAIC procedures for internet media portal service company.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.2
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• pp.215-222
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• 2009

This study compares the performance of the filters with various media in pretreatment of seawater desalination by reverse osmosis. For this purpose, Masan bay seawater is used as raw water. The filter performance is evaluated by the filtrate quality and the head loss development. Five media is selected in this study: anthracite, $Filtralite^{(R)}$, sand, Pumice, $AFM^{(R)}$. These media are used in combination for dual media filter and alone for mono media filter. The comparison results show that NC0.8-1.6 is the best $Filtralite^{(R)}$. The dual media filter of NC0.8-1.6 and sand outperformed other filters in particle removal. The dual media filter of anthracite and sand showed good performance in organic removal. The mono media filter of Pumice produced the similar filtrate quality as the mono media filter of sand although the effective size of Pumice is considerably greater than that of sand. Due to big size, head loss development is maintained slow in the filtration of Pumice.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.481-488
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• 1995

This study was carried out to evaluate the variations of headloss rate and of specific deposit to depths with effective size of media and configuration of filter layer during algae blooming period. 0.51mm size media was disqualified because most of headloss occurred rapidly below 5cm from surface layer however 0.91mm size media acted deep filtration more than 20cm from top, as result 0.91mm sixte media filter had 2~3 times longer filtration time than 0.51mm sixte media filter, but 0.91mm size media have break-through potentiality. multi-layer filter with 1.02mm anthracite and 0.51mm sand had large deposit volume in upper layer that could longer filtration time, moreover smaller media in lower layer that could protect break-through.

• Journal of Korean Academy of Nursing
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• v.51 no.1
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• pp.68-79
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• 2021

Purpose: This study aimed to analyze the mass and social media contents and structures related to particulate matter before and after the policy enforcement of the comprehensive countermeasures for particulate matter, derive nursing implications, and provide a basis for designing health policies. Methods: After crawling online news articles and posts on social networking sites before and after policy enforcement with particulate matter as keywords, we conducted topic and semantic network analysis using TEXTOM, R, and UCINET 6. Results: In topic analysis, behavior tips was the common main topic in both media before and after the policy enforcement. After the policy enforcement, influence on health disappeared from the main topics due to increased reports about reduction measures and government in mass media, whereas influence on health appeared as the main topic in social media. However semantic network analysis confirmed that social media had much number of nodes and links and lower centrality than mass media, leaving substantial information that was not organically connected and unstructured. Conclusion: Understanding of particulate matter policy and implications influence health, as well as gaps in the needs and use of health information, should be integrated with leadership and supports in the nurses' care of vulnerable patients and public health promotion.

• Korean Journal of Environmental Biology
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• v.24 no.3
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• pp.275-281
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• 2006

We examined effects of water temperature, salinity, irradiance, and different media on the growth of the toxic dinoflagellate Alexandrium tamarense (HYM9704), which was isolated from Jinhae Bay, Korea. The ranges of temperature and salinity in which the strain was able to grow were $10{\sim}20^{\circ}C$ and $20{\sim}34$ psu, respectively. These values were in accordance with those observed in situ. The maximum growth rates of axenic A. tamarense (HYM9704) was $0.25d^{-1}$ at $15^{\circ}C$, 30 psu, and $100{\mu}Em^{-2}s^{-1}$. The temperature affected the growth rates of axenic A. tamarense more significantly than the salinity. The type of culture media did not affect the growth rates of axenic A. tamarense. The strain in N-limited and P-limited media went into the stationary phase faster than that in T1 and T1/2 medium.

• Journal of Communications and Networks
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• v.10 no.4
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• pp.430-436
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• 2008

Recent studies have convinced that network coding can improve the performance of live media streaming in terms of startup delay, resilience to peer dynamics, as well as reduced bandwidth cost on dedicated streaming servers. However, there still exist some strategy drawbacks and neglected problems which need to be further researched. In addition to the commonly used evaluation parameters of the network and user experiences mentioned above, we focus on additional key factors, playback lag and switch lag, which have not been fully explored in previous work. In this paper, we present SonicStream, a novel and fully implemented live peer to peer (P2P) media streaming system with consideration of rich user experiences, including startup delay, playback continuity, playback lag, switch lag, etc. In pursuit of a further enhanced user experience, we revise traditional peer selection/data scheduling methods. Through a series of experimental evaluations and a cautious comparison with the latest similar work $R^2$, the superior performance of SonicStream has been preliminarily verified.

• Journal of Mushroom
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• v.5 no.2
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• pp.76-80
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• 2007

After bottle culture of Pleurotus eryngii, media were taken out the bottle and normally utilized compost. However, nutritional elements were remained in the waste media. This study was carried out to investigate the reusable possibility and the optimal additive rate of waste media in an artificial cultivation of Pleurotus eryngii. The pH had tendency to decrease as the waste media was added from 6.0 to 4.8. Based on the additive rate of 10, 20, 30, 40, and 50%, each treatment waste media was added to new media for culturing Pleurotus eryngii. Among various treatments, the mycelial growth and primordia formation of Pleurotus eryngii were more favorable in the addition of 10-30% waste median than in the addition of 40 and 50%. The yield of its fruiting body was increased slightly in the treatment of 10-30% waste media.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06a
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• pp.50-51
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• 2010

• Journal of Distribution Science
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• v.22 no.1
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• pp.79-94
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• 2024

Purpose: The popularity of social media has altered how customers interact with businesses, and an increasing number of customers prefer to voice their complaints on social media. Bystanders can observe the customer complaint process on social media, but the impact of transparency on bystanders remains uncertain. Therefore, this study established and verified a model for defining the effect of transparency and service recovery types on bystanders. Research Design and Methodology: In this study, we used the internet survey platform "So Jump" to collect data. And we validated three studies with SPSS 26.0 and Smart PLS 4.0. Result: First, we showed that the transparency process (vs. result) is more likely to increase customer forgiveness and E-loyalty and reduce E-NWOM intention among bystanders. Second, customer forgiveness also plays a complementary mediating role between transparency and E-loyalty, as well as between transparency and E-NWOM intention. Finally, we found a modest interaction effect between transparency (process vs. result) and service recovery types (psychological vs. tangible vs. hybrid) on bystanders' customer forgiveness and E-loyalty. Conclusions: This study provides actionable recommendations for how service managers can effectively employ social media as a means for distributing feedback information to manage service recovery in the future.