• Title/Summary/Keyword: Resource Availability

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An Adaptive Storage System for Enhancing Data Reliability in Solar-powered Sensor Networks (태양 에너지 기반 센서 네트워크에서 데이터의 안정성을 향상시키기 위한 적응형 저장 시스템)

  • Noh, Dong-Kun
    • Journal of KIISE:Computer Systems and Theory
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    • v.36 no.5
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    • pp.360-370
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    • 2009
  • Using solar power in wireless sensor networks requires a different approach to energy optimization from networks with battery-based nodes. Solar energy is an inexhaustible supply which can potentially allow a system to run forever, but there are several issues to be considered such as the uncertainty of energy supply and the constraint of rechargeable battery capacity. In this paper, we present SolarSS: a reliable storage system for solar-powered sensor networks, which provides a set of functions, in separate layers, such as sensory data collection, replication to prevent failure-induced data loss, and storage balancing to prevent depletion-induced data loss. SolarSS adapts the level of layers activated dynamically depending on solar energy availability, and provides an efficient resource allocation and data distribution scheme to minimize data loss.

Biodiesel Production From Fat of Tra Catfish and Basa Catfish (Viet Nam) Using Alkaline Catalysts

  • Huong, Le Thi Thanh;Tan, Phan Minh;Hoa, Tran Thi Viet;Lee, Soo
    • Journal of the Korean Applied Science and Technology
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    • v.25 no.3
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    • pp.299-312
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    • 2008
  • The fat of Tra and Basa catfish (Mekong Delta, Viet Nam) was evaluated for the first time as the potential feedstock for biodiesel production, due to its abundance, availability and cheap cost. The unsaturated fatty acid contents of Tra and Basa fat were 57.97% and 64.17%, respectively. Biodiesel was prepared from Tra and Basa fat by methanolysis reaction using alkali catalysts like sodium hydroxide and potassium hydroxide. Effects of various process parameters on biodiesel production, such as molar ratio of methanol to fat, catalyst concentration, temperature and time were investigated. As those results, the transesterification can be performed under moderate conditions, and the biodiesel yields were shown more than 90%. KOH catalyst was the best catalyst for biodiesel production from both Basa and Tra fat. As the feedstock aspect, Basa fat was indicated more efficiency than that of Tra fat. The maximum yield could be achieved by the transesterification from Basa fat with 5:1 molar ratio of methanol to fat, 0.8% KOH catalyst, $50^{\circ}C$, and 50 min. For Tra fat, the optimal condition were at 6:1 molar ratio of methanol to fat, 0.8% KOH catalyst, $50^{\circ}C$, and 45 min. Nowadays, due to cheaper cost and abundance, Tra fat is a promised resource for cheap biodiesel production in Viet Nam.

PSYCHO-PHYSICAL ANALYSIS OF PAPER AND A NEW DESIGN CONCEPT OF PAPER MEDIA FOR THE NEXT CENTURY

  • Fumihiko ONABE
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 1999.11b
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    • pp.209-213
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    • 1999
  • In the society of the 21\ulcorner century under multiphase media conditions, the rapidly glowing electronic media will replace the conventional paper media in a variety of areas. However, if human being still has an affinity for paper media and an instinct for hardcopy from electronic-based text or image, the new market will be created for the paper industry. To what extent the consumer choses paper media for output will depend upon the availability of functions of paper media appealing to human senses; i.e., "sensory functions of paper". As a whole, on-demand type personal as well as business communications will increase in the next century and this trend will lead certainly to a rapidly expanding "contents hardcopy market". The technological progress of the paper industry in the 21\ulcorner century depends upon the market needs for higher products quality and higher efficiency of manufacturing process as well as an endeavour to overcome constraints from forest resource, energy, and environmental issues. Under the conditions with above constraints, the paper media will be polarized into two categories; (1)paper for higher image reproduction capability for original image or text and (2)paper for lower reproduction but with higher appeals for human senses. To cope with these trends, psycho-physical analysis and a sensory engineering approach for developing new paper media is vitally required. Also newly emerged roles of paper physics in the multimedia age is pointed out associated with sensory functions of paper that are not well-understood so far.

Evaluation for User Experience about Interface Design of Video-Sharing Website -Mainly with Analysis on 'YouTube' and 'Vimeo'- (영상 공유 사이트의 인터페이스 디자인에 따른 사용자 경험 연구 -유튜브(YouTube)와 비메오(Vimeo)를 중심으로-)

  • Lee, Seung-Yun;Kim, Seung-In
    • Journal of Digital Convergence
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    • v.14 no.8
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    • pp.423-429
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    • 2016
  • The study evaluates user experiences of YouTube and Vimeo, typical Video-sharing websites, to suggest guidelines that are more user-cantered and useful. I did some literature research followed with evaluation of theoretical backgrounds, present conditions and future services. Also, I used the six principles of "Creating Pleasurable Interface" by Stephen Anderson to conduct an in-depth interview. The results indicate that YouTube needs to improve availability of its functions and usability by reducing advertisement. Vimeo needs to improve its popularity by increasing popular contents and add relationship service such as personal broadcasting system and community services. I expect this study will become a good resource for upgrading user experiences of Video-sharing websites. I also believe that this study can guide other studies about user experience in other fields.

Strategies for Increasing Biomass Energy Utilization in Rural Areas - Focusing on heating for greenhouse cultivation - (농촌지역 바이오매스 에너지 보급 활성화 전략 - 시설재배 난방을 중심으로 -)

  • Hong, Seong Gu
    • Journal of The Korean Society of Agricultural Engineers
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    • v.57 no.6
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    • pp.9-20
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    • 2015
  • The demand of renewable energy is expected to grow in the long run in spite of current stable lower oil prices. Energy consumption for heating in horticulture greenhouse is large and affects the profits of the farms. This study analyzed the availability of biomass in rural area and proposed the strategies for utilizing the biomass for greenhouse heating. Data reveal the annual average fuel consumption in greenhouses is about 78 TOE/ha. Considering biomass resource in rural areas, agricultural residues are not sufficient to meet the biomass demand from greenhouses. Therefore it is recommended to secure further biomass including wild herbaceous biomass and woody biomass from forest. Based on the conditions of biomass gasification equipment investment and fuel prices, maximum allowable price of biomass turned out about 100,000 KRW/t to be competitive to kerosine. Biomass supply chain should be established for facilitating biomass trading between biomass consumers and biomass producers such as farmers who provide crop residues. An online trading system is an example of the system where consumers who utilize biomass make payments to suppliers and get the information about the biomass. Intermediate collection storages are required to store biomass from distributed sources. Operation of biomass heating systems in demonstration greenhouses is necessary to get information to refine and further develop commercial biomass heating systems. Relatively large greenhouses are desirable to have biomass heating systems for economic viability. The location of the greenhouse farms should be selected within the area where enough biomass resources are available for feeding the biomass facility.

Higher Biomass Productivity of Microalgae in an Attached Growth System, Using Wastewater

  • Lee, Seung-Hoon;Oh, Hee-Mock;Jo, Beom-Ho;Lee, Sang-A;Shin, Sang-Yoon;Kim, Hee-Sik;Lee, Sang-Hyup;Ahn, Chi-Yong
    • Journal of Microbiology and Biotechnology
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    • v.24 no.11
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    • pp.1566-1573
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    • 2014
  • Although most algae cultivation systems are operated in suspended culture, an attached growth system can offer several advantages over suspended systems. Algal cultivation becomes light-limited as the microalgal concentration increases in the suspended system; on the other hand, sunlight penetrates deeper and stronger in attached systems owing to the more transparent water. Such higher availability of sunlight makes it possible to operate a raceway pond deeper than usual, resulting in a higher areal productivity. The attached system achieved 2.8-times higher biomass productivity and total lipid productivity of $9.1g\;m^{-2}day^{-1}$ and $1.9g\;m^{-2}day^{-1}$, respectively, than the suspended system. Biomass productivity can be further increased by optimization of the culture conditions. Moreover, algal biomass harvesting and dewatering were made simpler and cheaper in attached systems, because mesh-type substrates with attached microalgae were easily removed from the culture and the remaining treated wastewater could be discharged directly. When the algal biomass was dewatered using natural sunlight, the palmitic acid (C16:0) content increased by 16% compared with the freeze-drying method. There was no great difference in other fatty acid composition. Therefore, the attached system for algal cultivation is a promising cultivation system for mass biodiesel production.

Present and Future of Agricultural Extension System in Uganda (우간다 농촌지도사업의 현재와 미래)

  • Oumo, Florence Imaikorit;Cho, Gyoung-Rae
    • Journal of Agricultural Extension & Community Development
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    • v.21 no.1
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    • pp.245-272
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    • 2014
  • This study aims to explore the present and future of agricultural extension system in Uganda. Though Uganda has used many approaches in its agricultural extension, very little has been registered in farm productivity and profitability. Too many reforms some of them some are top-down while others are bottom - up. In most cases these reforms may not be given a chance to develop to show their impact. Future success of agricultural extension and rural development efforts in Uganda will depend not only on the presence of technical expertise and availability of resources but also on each government's willingness to redefine the role of its institutions and to allow the active participation of rural people in formulating and implementing and agricultural extension and rural development programs. As result the public extension systems in Uganda needs to be demand-driven so to make it relevant and important to the beneficiary.

Production of DME from CBM by KOGAS DME Process (KOGAS DME 공정을 이용한 CBM으로부터 DME 생산)

  • Cho, Won-Jun;Mo, Yong-Gi;Song, Taek-Yong;Lee, Hyen-Chan;Baek, Young-Soon;Denholm, Douglas;Ko, Glen;Choi, Chang-Woo
    • Journal of Hydrogen and New Energy
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    • v.22 no.6
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    • pp.925-933
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    • 2011
  • The traditional feedstock for dimethyl ether (DME) has been natural gas obtained by pipeline from a nearby natural gas or oil field. This report focuses on other feedstock: Coal bed methane (CBM). The resource availability and suitability of CBM for DME manufacturing have been investigated. CBM in a short time has become an important industry, providing an abundant clean-burning fuel and also suggesting as a feedstock for gas industry. The use of CBM will have very little impact on the KOGAS' DME process design and economics up to 50 vol% of $CO_2$ in the CBM source. Many of the CBM sources in Asia are high in $CO_2$, but pose no difficulties for the KOGAS' DME plant. Since tri-reformer requires substantial $CO_2$ in its feed, no $CO_2$ removal from the CBM feed is needed. The $CO_2$ in the CBM means that less $CO_2$ needs to be recycled from the downstream in the process.

An Efficient MPLS Routing System for Supporting QoS and Best-Effort Services (QoS 서비스와 최선형 서비스를 위한 효율적인 MPLS 라우팅 시스템)

  • Jeon, Hahn-Earl;Kim, Sung-Dae;Shin, Yong-Chul;Lee, Jai-Yong;Kim, Hyung-Taek
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.1B
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    • pp.71-79
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    • 2003
  • As the traffic grows rapidly in the Internet, the QoS guarantee of the flows and the traffic engineering problems have become very important issues. MPLS has more advantages to solve the problems than existing IP routing because of its use of multiple paths between the source and destination pairs Particularly, the availability of Constraint-based Shortest Path First(CSPF) algorithm and explicit route in MPLS made the problem referred above to be solved efficiently. However, the CSPF algorithm has the characteristic of selecting the shortest path of all paths which meet the traffics' QoS constraints Therefore, even though there are alternative paths to route traffic, alternate QoS paths may not be found and best-effort traffic will be dropped during congestion period In this paper, we present the network resource optimization method related to the traffic engineering by using load balancing through routing in MPLS network.

Real-Time Monitoring System Based on IPv6 over BLE (BLE 상의 IPv6 기반의 실시간 모니터링 시스템)

  • Kim, Seong-Woo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.2
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    • pp.309-315
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    • 2017
  • Recently it has drawn much attention on the technologies about Internet of Things (IoT) which connects objects with constrained resource and heterogenous communication module in order to communicate information via internet. We propose a real-time sensor monitoring system based on IPv6 over Bluetooth Low Energy (BLE), which is included in Bluetooth 4.2 Specification. Since this system uses a publish-subsribe based IoT protocol, so called Message Queueing Telemetry Transport (MQTT), neither transforming network data nor any proxy server is needed in order to transmit data. Through the web client connected to this system, you can monitor sensor data sent by BLE device in real-time, intermediated via MQTT broker and then delivered to the client via HTTP and websocket protocol. In this paper we evaluated network capacity and availability of the implemented test platform. Thus by using this system it is possible to make development cost low and to construct IoT network with heterogenous devices easily.