• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.95-98
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• 2010

OpenFlow 는 인터넷 스위치(라우터 포함)를 부분적으로 개선하여 연구자가 기존 네트워크의 정상적인 서비스를 간섭하지 않으면서 새로운 네트워킹 기술을 테스트할 수 있는 미래인터넷 (Future Internet) 연구를 위한 프로토콜이다. 하지만 OpenFlow 기반 테스트베드의 상태 정보를 확인하고 발생한 플로우들을 제어할 수 있는 도구(tool)가 부족하여, 연구자가 실험의 다양성을 제공 받기 어렵다. ENVI(Extensible Network Visualization & Control Framework)는 OpenFlow 네트워크 가시화를 위한 프레임워크로, 사용자의 목적에 맞는 인터페이스를 만들도록 제공해 준다. 본 논문에서는 OpenFlow 기반 테스트베드의 토폴로지 정보 및 플로우 상태를 쉽게 확인하고, 플로우 경로를 제어하는 OpenFlow 제어기 응용의 개발과 ENVI 의 확장을 설계하고 이를 구현을 통해 검증한다.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.241-247
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• 2013

For in vitro minimal-growth conservation of S. sarmentosum, the in vitro shoots with 10 mm length were cultured on Murashige and Skoog's media (MS) containing different levels of agar (0.8, 1.2, 1.6, 2%), Gelrite (0.4, 0.6, 0.8, 1%), ABA (0, 5, 10, $20mg{\cdot}L^{-1}$), and sucrose (2, 3, 6, and 9%) without subculture at $4^{\circ}C$ and $25^{\circ}C$. All media were supplemented with $0.2mg{\cdot}L^{-1}$ BA, agar and Gelrite media, with 5% sucrose, sucrose media, with 1.2% agar, and ABA media, with 5% sucrose and 1.2% agar, respectively. In vitro minimal-growth conservation in room-temperature ($25^{\circ}C$) was effective in the media containing with $10mg{\cdot}L^{-1}$ ABA or 1.6% agar, and the healthy plantlets could be preserved for 10 months without subculture. After 12 months at $4^{\circ}C$, survival rate was 100% in all media. The in vitro minimal-growth conservation in low temperature ($4^{\circ}C$) was effective in the media containing with $10mg{\cdot}L^{-1}$ ABA or 6% sucrose, and the healthy plantlets could be preserved over 18 months without subculture. Especially, long-term conservation using minimal growth of S. sarmentosum was much more efficient in the medium containing high level sucrose at $4^{\circ}C$ compared to others.

• Journal of Korean Society of Forest Science
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• v.80 no.4
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• pp.436-444
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• 1991

To increase both the production of mushrooms and the usages of the residues (used media) for roughage, the pinchips(PC) and sawdusts(SD) of three Korean oak species were tested as cultivating media for Lentinus edodes with varing the composition of the media. The results are as follows. 1. Organic acids(tannic acid and citric acid), which were added in the PC medium to enrich the quality of mushrooms, did not increase the growths of the mycelia and the quality. 2. The mushrooms were able to be harvested from six months after beginning the cultivation. No significant differences were found among the qualities of the mushrooms produced by various treatments. 3. The contents of crude proteins(1.82-4.55%) in the used media were higher than those in woods (c.a. 0.7%), and the total digestible nutrients (44.0-46.0%) in the used medium were not much different from those in rice straws (c.a.48.0%). 4. The contents of some essential amino acids (methionine in the used medium of the tannic acid added PC or S.D. and isoleucine, phenylalanine and lysine in the used medium of the untreated PC or SD) were higher than those in the control (raw media). The contents of a few other essential amino acids (threonine, valine and arginine) were lower in the used media. Most nonessential amino acids in the used media, particularly in the used bed-log, appeared to decrease than those in the control.

• Journal of Korean Society on Water Environment
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• v.20 no.5
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• pp.500-505
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• 2004

While more attention has been paid in recent years to urban point source pollution control, no considerable measures have been taken to control urban non-point source pollution. Contaminants from non-point sources deposited on urban impermeable surfaces such as road and highway are easily released to the public waters by rainfall, leading to the deterioration in water quality in urban area. The present study investigated a system using filter media to reduce the level of contamination in urban road runoff. Three different media, designated as J-P (polypropylene, blowing type), B-P (polypropylene, fiber type), and P-F (Polyvinyl alcohol, cube and sheet type) were evaluated on the basis of pollutant removal efficiency as well as hydraulic property. Experiments were peformed using a 1/4-scale treatment unit at various pollutant roading and rainfall intensity with real rainwater runoff collected from road surfaces. The results at different rainfall intensities shows that the medium J-P is superior to the other media for water permeability. J-P was not blocked at 10 mm/hr rainfall and its permeability was stable. On the other hand, B-P and P-F resulted in substantial overflow ratio even at I mm/hr rainfall intensity. Comparing treatment efficiencies for suspended solids, all media showed similar removal ranged from 91 % to 95%. However, J-P seems to be better than the other media considering its higher water permeability. J-P and P-F, both hydrophobic, yielded over 76% of heavy metal removal. But, the hydrophilic media B-P showed much smaller removal ranging from 26% to 47%. This indicates that J-P and P-F are beneficial to remove heavy metal due to their hydrophobic property. The treatment efficiencies over PAHs (poly aromatic hydrocarbons) showed the similar removal efficiency ranging from 66% to 97% for all three media.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.177-185
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• 2008

Research on media access control (MAC) scheme for Wireless Sensor Network (WSN) has been mainly focused on energy efficiency improvement, while interest on latency is relatively weak. However, end-to-end latency could be a critical limitation specifically in the multi-hop network such as wireless multimedia sensor networks. In this paper we propose a media access control scheme with distributed transmission power control to Improve end-to-end transmission latency as well as reduce power consumption in multi-hop wireless sensor networks. According to the simulation results, the proposed scheme is turned out to be an energy efficient scheme with improved end-to-end transmission latency.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.1
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• pp.119-124
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• 2016

In this paper, we studied on MAC(Media Access Control) protocol for UAVs application. According to the number of UAVs, ground control station should control properly increased UAVs. So, we applied CSMA/CA that used in current civil aircraft to UAV communications and verified the applicability through comparison of throughput and delays of data with various message sizes, In the results, we confirmed applicability for UAVs MAC protocol.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.6
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• pp.1060-1064
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• 2006

Data collected by sensors in field are transmitted to the base station gathering all of data. Because sensors have to gather data in surroundings and periodically transmit data to the base station, it makes energy consumed much. In this paper, we mose the scheme that is to avoid traffic congestion with achievement of energy efficiency, so collected data is transmitted efficiently. This is to adjust transmission rate differently in case of increasing or decreasing traffic and minimize the energy consumption with setting ideal options up basic CSMA(Carrier Sense Multiple Access) protocol in each sensor. Through the simulation, we find the ideal CSMA options and apply the proposed scheme of traffic control mechanism to them and analyze them, then show energy efficiency and effective traffic control mechanism.

• Journal of Practical Engineering Education
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• v.9 no.2
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• pp.99-106
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• 2017

The most important thing in STEAM education is to enhance students' interest and understanding of science and technology. In this paper, we propose basic circuit system design and control method applicable to STEAM fusion education. The circuit system design practice using the breadboard is designated as an essential curriculum in the corresponding department at the high school and college level in the domestic curriculum. However, there is a lack of STEAM convergence implementation examples that can easily understand circuit system design and control methods. Therefore, we proposed and tested a method to implement and control a media art type circuit system.

• Smart Media Journal
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• v.11 no.11
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• pp.9-16
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• 2022

Among the types of robots, it is not easy to make a robot that walks on two legs. For this, it is necessary to be able to create software that can control precise servomotor settings and various operations. This process is very difficult for beginners and not easy to make because there is no suitable Arduino shield shape for the robot. Therefore, in this study, a method for manufacturing Arduino and plug-in type shield was proposed. In addition, the process of developing a PC control program that can simplify motion control, manufacturing a robot, and setting servo motor values to easily control motion was introduced. It is expected that this will be of great help to novice developers who are interested in making robots.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.497-503
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• 2022

This study was conducted to investigate the horticultural media + decomposed granite + reused rock wool in the following mixing ratio: Control = 100:0, M1 = 80:0:20, M2 = 60:30:10, M3 = 40:30:30, M4 = 30:40:30, M5 = 0:50:50 (reused rockwool : decomposed granite : horticultural media) and develop the physicochemical properties and the growth of 'Sulhyang' strawberry runner plant. In the physical aspect of the horticultural media, statistical differences were recognized that the bulk density and particle density were lower in the control and M1. But the bulk density and particle density were high in the M3, M4, and M5, because it had high mixing ratio between recycled rock wool and decomposed granite. EAW and WBC showed a similar tendency. The air porosity and total porosity were higher in control and M1 than M3, M4, M5. Exchangeable cation (K⁺, Ca²⁺, Na⁺, Mg²⁺) and base replacement capacity (CEC) were higher in control and M1, than M2, M3, M4, and M5. As a result of the cultivation of 'Sulhyang' runner plant, the plant length was long in M2, 32.1 cm and smaller than M5 to 28.4 cm. However, if the crown diameter, which is the growth indicator of the runner plant, all 6 treatments were formed 11.23 mm-12.03 mm, which is considered to be suitable for the growth of the runner plant. There wasn't a statistical difference between the weight and dry weight of the root. As a result, the growth difference of the seedlings by the horticulture media was similar. Therefore, considering the physical properties of the horticultural media, it was judged that the air porosity and total porosity would be improved when the recycled rock wool and the decomposed granite were properly mixed rather than the use of the horticultural media as a single medium, which would be advantageous for irrigation management.