• Title/Summary/Keyword: partition

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Energy Partition to Workpiece in Creep feed Grinding (크리피드연삭에서 공작물로 유입되는 에너지 비율)

  • 김남경;박호성;홍순익;송지복
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.799-804
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    • 1997
  • This paper is concerned with the heat flux distribution and energy partition for creep-feed grinding. Form measurements of transient grinding temperatures in the workpiece sub-surface using an embeded thermocouple, the overall energy partition to the workpiece was estimated form moving heat source theory for a triangular heat flux distribution as 3.0% for down grinding and 4.5% for up grinding. The higher energy partition for up grinding can be attributed to the need to satisfy thermal compatibility at the grinding zone. The influence of cooling outside the grinding zone can be analytically taken into account by specifying convective heat transfer coefficients on the workpiecs surface h /sab a/ heat source (grinding zone) and h /sab b/ behind the heat source. The smaller energy patition together with slightly lower grinding power favors down grinding over up grinding.

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EFFECT OF PARTITION AND SPECIES DIFFUSIVITY ON DOUBLE DIFFUSIVE CONVECTION OF WATER NEAR DENSITY MAXIMUM

  • Sivasankaran, S.;Kandaswamy, P.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.11 no.1
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    • pp.71-83
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    • 2007
  • The double diffusive convection of cold water in the vicinity of its density maximum in a rectangular partitioned enclosure of aspect ratio 5 with isothermal side walls and insulated top and bottom is studied numerically. A thin partition is attached to the hot wall. The species diffusivity of the fluid is assumed to vary linearly with concentration. The governing equations are solved by finite difference scheme. The effects of position and height of the partition, variable species diffusivity and enclosure width are analyzed for various hot wall temperatures. It has been found that adding partition on the hot wall reduces the heat transfer. The density inversion of the water has a great influence on the natural convection. When increasing species diffusivity parameter heat and mass transfer rate is decreased.

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BTEX와 액상간 분배성 알코올류 추적자의 분배특성 연구

  • Lee Seong-Su;Ju Sang-Yeon;Park Jun-Beom
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2006.04a
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    • pp.115-118
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    • 2006
  • The partitioning tracer method has been studied as an alternative method for characterizing aquifers contaminated by nonaqueous phase liquids (NAPLs). Accurate partition coefficients of tracers partitioning between NAPL and water are needed to improve the reliability of the partitioning tracer method. In this research, partition coefficients of alcohol tracers partitioning between benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds and water are estimated from using the approach of equivalent alkane carbon number (EACN). General agreement was observed in between the measured and estimated partition coefficients. Based on these results we can verify that the EACN approach is suitable for estimating the partition coefficient.

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Organic Pollutant Transport in Unsaturated Porous Media by Atmospheric Breathing Processes( I ) - Partition Coefficient -

  • Ja-Kong;Lim, Jae-Shin;Do, Nam-Young
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 1996.11a
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    • pp.50-53
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    • 1996
  • This paper reports the experimental results for the determination of the overall partition coefficient of VOCs in unsaturated soil, A chromatographic method was used for the determination of gaseous partition coefficients to natural soil under various water content conditions. The equilibrium vapor pressure of water over saturated salt solution was used to fix the relative humidity of the air and control the water content of the soil systems. The transport behavior was studied for dichloromethane, trichloroethane and dichlorobenzene pollutants, with log octanol-water partition coefficients(log $K_{ow}$ ) which range from 1.25 to 3.39, or water to soil partitioning which varies by 135 times; water solubility constants which vary by 3 times; and vapor pressures which range from 1 to 362 torr. Water content of the soil had a pronounced effect on the effective partition coefficient(between gas and soil + water stationary phase) as well as on the effective dispersion coefficient.

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Technical Development for the Circulating Fluidized Bed Combustor of firing Korean Low Grade Anthracite Coals (Particle Flow Patterns in a Circulating Fluidized-Bed with an internal Nozzle and a Partition Wall) (한국산 저질무연탄 연소용 순환식유동층 연소로 개발(간막이벽과 내부노즐을 설치한 순환유동층내에서의 유체거동))

  • Khee, Kwan-Seok
    • Journal of the Korean Society for Heat Treatment
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    • v.6 no.4
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    • pp.243-248
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    • 1993
  • A Circulating Fluidized-Bed (CFB) with an internal nozzle and a partition wall was proposed. The technique of fluidization is related to operations first used commercially in the fields of metallurgical and mechanical engineering such as the heat treatment of metals and power station combustors. In the modified CFB, an internal nozzle and a partition wall were additionally set in the main bed. This cold mode CFB apparatus made of acrylic resin; the main bed is 1,500mm high and 100mm in the inner diameter, the internal nozzle is 130mm high and 10mm in the inner diameter, and the partition wall is 7mm thick and 100mm in the diameter. Glass beads of $89{\mu}m$ in the mean diameter were employed as bed materials.

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A topology-based circuit partitioning for field programmable circuit board (Field programmable circuit board를 위한 위상 기반 회로 분할)

  • 최연경;임종석
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.34C no.2
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    • pp.38-49
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    • 1997
  • In this paper, w describe partitioning large circuits into multiple chips on the programmable FPCB for rapid prototyping. FPCBs consists of areas for FPGAs for logic and interconnect components, and the routing topology among them are predetermined. In the partition problem for FPCBs, the number of wires ofr routing among chips is fixed, which is an additonal constraints to the conventional partition problem. In order to deal with such aconstraint properly we first define a new partition problem, so called the topologybased partition problem, and then propose a heuristic method. The heuristic method is based on the simulated annealing and clustering technique. The multi-level tree clustering technique is used to obtain faster and better prtition results. In the experimental results for several test circuits, the restrictions for FPCB were all satisfied and the needed execution time was about twice the modified K-way partition method for large circuits.

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Effect of Soil Moisture on Partition of Mineral Nutrients in Panax ginseng (인삼의 무기양분 분배에 대한 토양수분의 영향)

  • Park, Hoon;Choi, Bayung-Ju
    • Journal of Ginseng Research
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    • v.7 no.1
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    • pp.74-79
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    • 1983
  • Effect of soil moisture on content and partition of mineral nutients in panax ginseng (2 years old) was investigated. Similarity was found between N and p, Ca and Mg, K and Fe. Mn and Zn were quite different each other and from others. Nutrient partition was affected more by nutrient content than by dry matter. Under suboptimal moisture condition partition to shoot was inhibited in order of Mg, Zn, Ca, Mg, N and P while accelerated in odor of Fe. K and Mn. Under supraoptimal moisture condition Partition to shoot was inhibited in order of Zn, Fe, K, and Ca, while accelerated in order of Mg, N, Mn and p.

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Infrared Image Enhancement Using A Histogram Partition Stretching and Shrinking Method (히스토그램 분할 펼침과 축소 방법을 이용한 적외선 영상 개선)

  • Jung, Min Chul
    • Journal of the Semiconductor & Display Technology
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    • v.14 no.4
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    • pp.50-55
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    • 2015
  • This paper proposes a new histogram partition stretching and shrinking method for infrared image enhancement. The proposed method divides the histogram of an input image into three partitions according to its mean value and standard deviation. The method stretches both the dark partition and the bright partition of the histogram, while it shrinks the medium partition. As the result, both the dark part and the bright part of the image have more brightness levels. The proposed method is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiments were conducted by using various infrared images. The results show that the proposed algorithm is successful for the infrared image enhancement.

A Hybrid Index of Voronoi and Grid Partition for NN Search

  • Seokjin Im
    • International journal of advanced smart convergence
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    • v.12 no.1
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    • pp.1-8
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    • 2023
  • Smart IoT over high speed network and high performance smart devices explodes the ubiquitous services and applications. Nearest Neighbor(NN) query is one of the important type of queries that have to be supported for ubiquitous information services. In order to process efficiently NN queries in the wireless broadcast environment, it is important that the clients determine quickly the search space and filter out NN from the candidates containing the search space. In this paper, we propose a hybrid index of Voronoi and grid partition to provide quick search space decision and rapid filtering out NN from the candidates. Grid partition plays the role of helping quick search space decision and Voronoi partition providing the rapid filtering. We show the effectiveness of the proposed index by comparing the existing indexing schemes in the access time and tuning time. The evaluation shows the proposed index scheme makes the two performance parameters improved than the existing schemes.

A research for partition recovery method in a forensic perspective (포렌식 관점의 파티션 복구 기법에 관한 연구)

  • Namgung, Jaeung;Hong, Ilyoung;Park, Jungheum;Lee, Sangjin
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.23 no.4
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    • pp.655-666
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    • 2013
  • As the capacity of storage devices becomes larger, most users divide them into several logical partitions for convenience of storing and controlling data. Therefore, recovering partitions stably which are artificially hidden or damaged is the most important issue in the perspective of digital forensic. This research suggests partition recovery algorithm that makes stable and effective analysis using characteristics of each file system. This algorithm is available when partition is not distinguishable due to concealment of partition or damage in partition area.