• Title/Summary/Keyword: Local sink

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Press Formability of Austenitic AISI304 Stainless Steel (오스테나이트계 AISI304 스테인레스강판의 프레스 성형특성)

  • Nam, J.B.;Ryoo, D.Y.;Kim, Y.S.
    • Transactions of Materials Processing
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    • v.3 no.1
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    • pp.38-50
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    • 1994
  • Fundamental deformation mechanism and plastic behavior of AISI304 austenitic stainless steel were investigated to evaluate press formability. Local and uniform deformation capacity of AISI304 steel were compared to those of ferritic AISI430 steel and Al killed low carbon steel. Nine kinds of austenitic stainless steels having different austenite stabilities were made in laboratory scale to examine the transformation behavior in various deformation mode and variation of mechanical properties. Deformation path and strain distributions along edge corner of commercial sink die were illustrated and effect of austenite stability on press forming of sink die was clarified with experiments using square cup drawing tools.

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Pressure Loss and Forced Convective Heat Transfer in an Annulus Filled with Aluminum Foam (발포 알루미늄이 삽입된 환형관에서의 압력손실 및 강제대류 열전달)

  • Noh Joo-Suk;Lee Kye-Bock;Lee Chung-Gu
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.9
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    • pp.855-862
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    • 2005
  • An experimental investigation has been carried out for aluminum foam heat sink inserted into the annulus to examine the feasibility as a heat sink for high performance forced water cooling in the annulus. The local wall temperature distribution, inlet and outlet pressures and temperatures, and heat transfer coefficients were measured for heat flux of 13.6, 18.9, 25.1, 31.4 $kw/m^2$ and Reynolds number ranged from 120 to 2000. Experimental results show that the friction factor is higher than clear annulus without aluminum foam, while the significant augmentation in Nu is obtained. This technique can be used for the compactness of the heat exchanger.

Data Dissemination Protocol Considering Target Mobility in Ubiquitous Sensor Network (유비쿼터스 센서 네트워크 환경에서 감지대상의 이동성을 고려한 데이터 전달 프로토콜)

  • Suh Yu-Hwa;Kim Ki-Young;Shin Young-Tae
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.3A
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    • pp.311-320
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    • 2006
  • This paper proposes DDTM for USN having end-point mobility. The existing network protocols did not consider target's and sink's mobility. So it requires flooding and path update whenever targets or sinks move. This can lead to drain battery of sensors excessively and decrease lifetime of USN. DDTM is the protocol based on TTDD considering sink's mobility. TTDD provides sink's mobility efficiently by using the grid structure, but it requires the high energy because of reconstructing the grid structure whenever targets move. In this way, the proposed protocol can decrease a consumption of energy, since it reuses the existing grid structure of TTDD, if the target moves in local cell. We compare DDTM with TTDD under the total message and the energy consumption by using a discrete analytical model for cost analysis. Analytical results demonstrated that our proposed protocol can provide the higher efficiency on target's mobility.

Local Update-based Multicasting Scheme for Mobile Sinks in Wireless Sensor Networks (무선 센서 망에서 이동싱크 지원을 위한 지역 수정 기반 멀티캐스팅 기법)

  • Lee, Jeong-Cheol;Park, Ho-Sung;Oh, Seung-Min;Jung, Ju-Hyun;Park, Soo-Chang;Lee, Eui-Sin;Kim, Sang-Ha
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.1
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    • pp.80-84
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    • 2010
  • Data multicasting from a source to multiple sinks in wireless sensor networks is used to achieve both reducing communication costs and energy efficiency. Almost all existing schemes for the multicasting might be effectively performed by optimal construction of a multicasting tree between a source and multiple stationary sinks. However, in practical sensor applications, sinks could move around on the wireless sensor networks for own missions, such as scouting of soldiers and saving lives of victims by firefighters. Unfortunately, the sink mobility causes frequent entire reconstruction of the multicasting tree and thus it leads to exhaustion of battery power of sensors. Hence, we propose an energy-efficient multicast protocol to support multiple mobile sinks by the local multicast tree reconstruction, called Local Update-based geographic Multicasting for Mobile sinks (LUMM) for wireless sensor networks. Our simulation results show that our scheme for mobile sinks is more efficient in terms of energy resource management than other exist works.

Publish/Subscrib Service based Selective Sensor Data Monitoring System using Mesh Network (메쉬 네트워크에서 가입/게시(subscribe/publish) 서비스기반 선택적 센서정보 모니터링 시스템)

  • Kim, Yong-Hyuck;Kim, Young-Han
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.3B
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    • pp.493-502
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    • 2010
  • In this paper we propose a scalable sensor network system that makes mesh network among the sink nodes to solve the scalability problem of existing sensor network which is caused by multi-hop networking between the sensor nodes. In the proposed system, the sink nodes have the wireless networking ability to communicate with another sink nodes in mesh fashion, and with the monitoring nodes which is located in the local area or internet area. Especially, the system includes L4(Application Layer) routing mechanism that provides subscribe/publish service to serve selective transmission of sensor data to the specific monitoring nodes. The collected sensor data is transmitted to the monitoring nodes when the sensor data is matched with the monitoring node's interesting value.

Experimental Simulation of Local External Forcing of the Contained Rotating Flow (회전반 유체실험에서 국지적 외력의 실험적 모의)

  • Yi, Chang-Won;Na, Jung-Yul
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.5 no.2
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    • pp.77-85
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    • 2000
  • Simulation of local external forcing and its response in the rotation table experiment has been investigated. Spatially-uniform external forcings have been applied in many experimental studies, however, based on the fact that the north-south distribution of the wind-stress curl and the existence of local maximum of the sea surface heat loss in the northern part of the East Sea, new method of combined effects of local forcings has been employed in separate experiments. Carefully designed local source or sink at the bottom of the cylindrical container can produce horizontal pressure gradient within the Ekman layer, and consequently the interior also attains the same pressure gradient that produces geostrophic interior circulation. In order to keep free surface during the local-surface cooling, a side-wall cooling method is suggested. For the various type of local forcing including the effects local cooling and the periodic change of local wind-stress curl, western-boundary flow in terms of its strength, position of separation from the boundary have been observed.

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Study on Forest Functions Classification using GIS - Chunyang National Forest Management Planning - (GIS를 이용한 산림기능구분에 관한 연구 - 춘양 국유림 산림경영계획구를 대상으로 -)

  • Kwon, Soon-Duk;Park, Young-Kyu;Kim, Eun-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.4
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    • pp.10-21
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    • 2008
  • A forest functions classification map is an essential element for the management planning of national forests. This study was intended to make out the map at the stand level by utilizing the Forest Functions Evaluation Program(FFEP), developed by Korea Forest Research Institute. In this program, the potential of each function was evaluated in each grid cell, and then a forest functions estimation map was generated based on the optimum grid cell values in each sub-compartment unit. Finally, the program produced a forest functions classification map with consideration of the priority of the functions. The final forest functions classification map required for the national forest management planning made out overlapping those results which the rest of the forest classified referring priority functions classification map to national forest manager and classified according to the local administrative guidance and sustainable forest resources management guidance. The results indicated that the forest function classification using the FFEP program could be an efficient tool for providing the data required for national forest management planning. Also this study made a meaningful progress in the forest function classification by considering the local forest administrative guidance and sustainable forest resources management guidance.

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Investigation on sink/source related traits and their relation of watermelon germplasm to promote use

  • Hwang, Hyun-Chul;Yi, Jung-Yoon;Rhee, Ju-Hee;Hur, On-Sook;Ro, Na-Young;Sung, Jung-Sook;Lee, Ho-Sun;Lee, Jae-Eun;Lee, Sok-Young
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2018.10a
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    • pp.75-75
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    • 2018
  • Watermelons, Citrullus species(Cucurbitaceae), are native to Africa and have been cultivated since ancient times. T he fruit flesh of wild watermelon is watery, but typically hard-textured, pale-colored and bland or bitter. The familiar sweet dessert watermelons, C. lanatus, featuring non-bitter, tender, well colored flesh, have a narrow genetic base, suggesting that they are originated from a series of selection events in a single ancestral population. In this study, considered as sweet dissert watermelon, genetic resources, C. lanatus, comprising of traditional cultivars and local accessions were collected from 18 different countries in four continents. A total of 60 accessions were characterized morphologically according to RDA genebank descriptors combined with Japan and China, list for 11 qualitative characteristics, leaf length, leaf width, petiole length, petiole diameter-source, stalk end length, stalk diameter, fruit length, fruit diameter, rind thickness, flesh sugar content($^{\circ}brix$), fruit weight-sink, and 6 sink related characters, leaf margin incision-source, fruit shape, fruit skin ground color, fruit skin stain color, fruit skin stain pattern and flesh color-sink, were also investigated. Even though the relatedness between some morphological traits and fruit weight or fruit sweetness showed no significance, the accessions investigated have a great deal of variation for most of the morphological traits. Additionally, the accessions which showed good performance in flesh color and fruit shape (IT271048) and high sugar content of flesh (IT274119, IT290118) above 14brix, were investigated in this experiment. The accessions, which have the information on specific traits including the selected accessions could be introduced, distributed and investigated for further use.

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Mercury Fluxes from the Nan-Ji-Do Area of Seoul -Application of Micrometerorological Methods (미기상학적 기법을 응용한 난지도지역이 수은교환율 측정연구)

  • 김민영;김기현;이강웅;정일현
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.6
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    • pp.585-594
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    • 2000
  • Through an application of Micrometerorological methods, we conducted measurements of Hg fluxes from Nan-Ji-Do which is well known as one of the major local areal sources in Seoul metropolitan area during Match/April of 2000. In the course of our study, we determined the concentration gradients of total gaseous Hg(between 20 and 2000 cm heights) and combined these data with Micrometerorological components to derive is fluxes. It turned out that emission from and dry deposition to soil surfaces occurred at the ratio of 72:27 from a total of 271 hourly measurements. The validity of measured concentration gradients( or resulting fluxes) was evaluated in terms of percent gradient. Accordingly, about more than 95% of gradient data derived were statistically significant. The mean fluxes of Hg across soil-air interface, when computed using the concentrations gradients and relevant parameters, were found at 253(during emission) and -846ng/$m^2$/h(during dry deposition) The occurrences of abnormalously high exchange rates appear to be the combined effects of enormously high gradient values and high transfer coefficients. While the emissions of Hg occurred constantly during the whole study periods, the occurrences of dry deposition events were observed most intensively during very limited time periods(3/29 and 4/3). The results of our study cleary indicated that the studied area is a strong local areal source, while exhibiting great potential as a major sink simultaneously.

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