• Title/Summary/Keyword: sink and source.

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Sensitivity of Input Parameters in the Spectral Wave Model

  • Park, Hyo-Bong
    • Journal of Ocean Engineering and Technology
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    • v.23 no.2
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    • pp.28-36
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    • 2009
  • Many researches have been done to define the physical parameters for the wave generation and transformation over a coastal region. However, most of these have been limited to the application of particular conditions, as they are generally too empirical. To yield more reasonable wave estimation using a spectral wave model, it is important to understand how they work for the wave estimation. This study involved a comprehensive sensitivity test against the spectral resolution and the physical source/sink terms of the spectral wave model using SWAN and TOMAWAC, which have the same physical background with several different empirical/theoretical formulations. The tests were conducted for the East Anglian coast, UK, which is characterized by a complex bathymetry due to several shoals and offshore sandbanks. For the quantitative and qualitative evaluation of the models' performance with different input conditions, the wave elements and spectrums predicted at representative sites the East Anglia coast were compared/analyzed. The spectral resolution had no significant effect on the model results, but the lowest resolution on the frequency and direction induced underestimations of the wave height and period. The bottom friction and depth-induced breaking terms produced relatively high variations in the wave prediction, depending on which formulation was applied. The terms for the quadruplet and whitecapping had little effect on the wave estimation, whereas the triads tended to predict shorter and higher waves by energy transferring to higher frequencies.

An Energy Efficient Communication Protocol using Location Information in Wireless Sensor Networks (무선 센서 망에서 위치 정보를 이용한 에너지 효율적인 통신 프로토콜)

  • Jin, Min-Sook;Park, Ho-Sung;Lee, Eui-Sin;Kim, Tae-Hee;Lee, Jeong-Cheol;Kim, Sang-Ha
    • Journal of KIISE:Information Networking
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    • v.36 no.4
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    • pp.322-329
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    • 2009
  • Many researches in wireless sensor networks have used a geographic routing to effectively disseminate data between sinks and sources. To know the location information, the geographic routing has proposed two manners. A sink-initiated and a source-initiated are flooding to disseminate its location information in WSN. However, these two manners have two problems. Firstly, whenever they move, they flood their location information. Secondly, their location information is disseminated unnecessary nodes besides nodes which send and receive data in actually. Therefore, this paper proposes a protocol that can solve the two problems and disseminate effectively data between few sinks and few sources. The proposed protocol exploits a location information manager that manages location information of the sinks and the sources. We also compare the performance of the proposed protocol with the existing protocols through a simulation.

Experimental Study on the Development of Food Drying Machine for Home Use Using Low Electricity (저전력 가정용 식품건조기 개발에 관한 실험적 연구)

  • Kim, Soon-Ho;Kim, Ki-Wan;Kim, Hoon
    • Journal of Power System Engineering
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    • v.19 no.4
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    • pp.43-49
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    • 2015
  • This study has been analyzed and investigated the possibility for the substitution of a heat source with the application of PTC(Positive Temperature Coefficient Heater) in a food drying machine. And this experiment was conducted to measure temperatures at the upper part of the vessel and the heat sink. And the structure has the many holes plane connected with the external air in the upper part of similar volumetric vessel, and attached to the PTC heater (3sets) of total consumption electricity of 120[W] in Al radiant heat structure and the small fan (2sets) in the suitable space of the lower part. Consequently, it was found that at the most conditions of food drying test with the seven holes(5mm) under the control temperature $62^{\circ}C$, the optimum drying condition formatted and the optimum time range especially appeared from 6,500 second to 7,000 second in case of drying test on banana sample.

An Origin-Centric Communication Scheme to Support Sink Mobility for Continuous Object Detection in IWSNs (산업용 무선 센서망을 이용한 연속개체 탐지에서 이동 싱크 지원을 위한 발원점 중심의 통신방안)

  • Kim, Myung-Eun;Kim, Cheonyong;Yim, Yongbin;Kim, Sang-Ha;Son, Young-Sung
    • KIPS Transactions on Computer and Communication Systems
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    • v.7 no.12
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    • pp.301-312
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    • 2018
  • In industrial wireless sensor networks, the continuous object detection such as fire or toxic gas detection is one of major applications. A continuous object occurs at a specific point and then diffuses over a wide area. Therefore, many studies have focused on accurately detecting a continuous object and delivering data to a static sink with an energy-efficient way. Recently, some applications such as fire suppression require mobile sinks to provide real-time response. However, the sink mobility support in continuous object detection brings challenging issues. The existing approaches supporting sink mobility are designed for individual object detection, so they establish one-to-one communication between a source and a mobile sink for location update. But these approaches are not appropriate for a continuous object detection since a mobile sink should establish one-to-many communication with all sources. The one-to-many communication increases energy consumption and thus shortens the network lifetime. In this paper, we propose the origin-centric communication scheme to support sink mobility in a continuous object detection. Simulation results verify that the proposed scheme surpasses all the other work in terms of energy consumption.

Mineral Movement in Relation to Pollination in Two Perennial Plants (두 다년생 식물에 있어서 수분에 따른 무기물의 이도 양상)

  • 강혜순
    • Journal of Plant Biology
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    • v.34 no.2
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    • pp.151-158
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    • 1991
  • A new technique involving gamma-spectrometry was used to determine the effects of pollination on mineral uptake in petals, ovaries and leaves of tulips and daffodils. A gamma-emitting radionu'::lide solution containing selenium-75, cesium-137, manganese-54, and zinc-65 was applied to the roots of tulips and daffodils growing in water. Mineral uptake was monitored in plant parts over a 24 day period. Pollinated tulip flowers showed a rapid withdrawal of minerals from the petals and an increase in ovary mineral content, while such a source-sink relationship was not established in daffodils. In both species, the concentration of most minerals in petals and ovaries declined prior to abortion of the plant part. The roots and bulbs of the plants contained the vast majority of the labeled minerals. This study demonstrated a possibility that certain plant parts could be isolated and monitored for mineral uptake over time without destruction.uction.

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Enhanced Hybrid Routing Protocol for Load Balancing in WSN Using Mobile Sink Node

  • Kaur, Rajwinder;Shergi, Gurleen Kaur
    • Industrial Engineering and Management Systems
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    • v.15 no.3
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    • pp.268-277
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    • 2016
  • Load balancing is a significant technique to prolong a network's lifetime in sensor network. This paper introduces a hybrid approach named as Load Distributing Hybrid Routing Protocol (LDHRP) composed with a border node routing protocol (BDRP) and greedy forwarding (GF) strategy which will make the routing effective, especially in mobility scenarios. In an existing solution, because of the high network complexity, the data delivery latency increases. To overcome this limitation, a new approach is proposed in which the source node transmits the data to its respective destination via border nodes or greedily until the complete data is transmitted. In this way, the whole load of a network is evenly distributed among the participating nodes. However, border node is mainly responsible in aggregating data from the source and further forwards it to mobile sink; so there will be fewer chances of energy expenditure in the network. In addition to this, number of hop counts while transmitting the data will be reduced as compared to the existing solutions HRLBP and ZRP. From the simulation results, we conclude that proposed approach outperforms well than existing solutions in terms including end-to-end delay, packet loss rate and so on and thus guarantees enhancement in lifetime.

Study for grain-filling of rice using 13C labeling flow-metabolome analysis

  • Okamura, Masaki;Hirai, Masami Yokota;Sawada, Yuji;Okamoto, Mami;Arai-Sanoh, Yumiko;Yoshida, Hiroe;Mukouyama, Takehiro;Adachi, Shunsuke;Fushimi, Erina;Yabe, Shiori;Nakagawa, Hiroshi;Kobayashi, Nobuya;Kondo, Motohiko
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.59-59
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    • 2017
  • Rice (Oryza sativa L.) is the most important crop and its yield must be improved to feed the increasing global population. Recently developed high-yielding varieties with extra-large sink capacity often have a problem in unstable grain-filling. Therefore, understanding limiting factors for improving grain-filling and controlling them are essential for further improvement of rice grain yield. However, since grain-filling rate was determined by complex sink-source balance, the ability of grain-filling was very difficult to evaluate. Source ability for 'grain' was not only determined by the ability of carbon assimilation in leaves, but also that of carbon translocation from leaves to panicles. Sink strength was determined by the complex carbon metabolism from sucrose degradation to starch synthesis. Hence, to evaluate the grain-filling ability and determine its regulatory steps, the whole picture of carbon flow from photosynthesis at leaves to starch synthesis at grains must be revealed in a metabolite level. In this study, the yield and grain growth rate of three high-yielding varieties, which show high sink capacity commonly, were compared. Momiroman showed lower grain filling rate and slower grain growth rate than the other varieties, Hokuriku 193 and Tequing. To clarify the limiting point in the carbon flow of Momiroman, $CO_2$ labeled by stable isotope ($^{13}C$) was fed to three varieties during ripening period. The ratio of $^{13}C$ left in the stem was higher in Momiroman 24 hours after feeding, suggesting inefficient carbon translocation of Momiroman. More interestingly, $^{13}C$ translocation from soluble fraction to insoluble one in the grain seemed to be slower in Momiroman. To get the further insight in a metabolite level, we are now trying the $^{13}C$ labeling metabolome analysis in the developing grains.

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