• 제목/요약/키워드: the diffusion process

검색결과 2,047건 처리시간 0.033초

네트워크 외부효과를 고려한 두 단계 공급체인에서의 신기술 도입과 확산속도에 대한 연구 : 구매자-공급자간 관계 요인에 대한 모형 (Adoption and Diffusion Speed of New Technology with Network Externality in a Two-level Supply Chain : An Approach to Relative Factors in Buyer-Supplier Relationships)

  • 최대헌
    • 한국경영과학회지
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    • 제38권3호
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    • pp.51-70
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    • 2013
  • This paper develops a model to predict the adoption and level of usage of network technology in a two-level supply chain with buyer-supplier relationships. A firm's adoption of a new technology depends not only on its own beliefs of the new technology's costs and benefits, but also on the adoption decisions of other firms in the supply chain. A model first analyzes an individual supplier's decision about a new technology adoption considering with multiple suppliers and buyers. Individual suppliers' decisions are aggregated with a population model to project how new technology diffuses across the supply chain and examine the pattern of diffusion process. This study found that as more firms adopt in initial periods, the total amount of information to the potential adopters in the population increases, and then the number of firms persuaded by the information increases as the process moves up the distribution of adoption process. We consider three factors influencing the diffusion speed of the new technology in a supply chain network : mean benefits, cost sharing, and information provision. This study examines how such factors affect the reduction of threshold levels, which implies that reductions in threshold levels have an aggregate effect by accelerating the rate of adoption. In particular, we explore relationship factors available in practice in a buyer-supplier relationship and numerically examines how these relationship factors contribute to increase the diffusion speed of the technology in a two-level supply chain.

확산망에 의한 방향성 계층적 공간 필터의 구현 (Implementation of Hierarchical Spatial Filters with Orientation Selectivity by Using Diffusion Network)

  • 최태완;김재창
    • 전자공학회논문지B
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    • 제33B권10호
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    • pp.130-138
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    • 1996
  • In this paper, we propose a neural network which detect edges of different orentation and spatial frequency in arbitrary image data. We constructed the proposed neural network iwth two different types neural network. A diffusion network performs the gaussian operation efficiently by the diffusion process. And the spatial difference network has specially designed connections suitble to detect the contours of a specific oriention. Simulation results showed that the proposed neural network can extract the edges of selected orientation efficiently by applying the neural network to a test pattern and the real image.

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비등방형 확산과 계층적 클러스터링을 이용한 칼라 영상분할 (Color Image Segmentation Using Anisotropic Diffusion and Agglomerative Hierarchical Clustering)

  • 김대희;안충현;호요성
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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    • pp.377-380
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    • 2003
  • A new color image segmentation scheme is presented in this paper. The proposed algorithm consists of image simplification, region labeling and color clustering. The vector-valued diffusion process is performed in the perceptually uniform LUV color space. We present a discrete 3-D diffusion model for easy implementation. The statistical characteristics of each labeled region are employed to estimate the number of total clusters and agglomerative hierarchical clustering is performed with the estimated number of clusters. Since the proposed clustering algorithm counts each region as a unit, it does not generate oversegmentation along region boundaries.

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확산구동재결정에 의한 TiC 소결체의 기계적성질 변화 (Effect of Diffusion Induced Recrystallization on the Mechanical Properties of Sintered TiC)

  • 채기웅
    • 한국세라믹학회지
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    • 제35권2호
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    • pp.196-200
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    • 1998
  • Effect of diffusion induced recrystallization(DIR) on mechanical properties of hot-pressed TiC was in-vestigated. The TiC specimen was electroplated with Cr and then heat-treated at 1550. Through the DIR process a new set of (Ti, Cr) C mixed carbide grains with uniform and small size was formed at the surface. As a consequence the scattering in fracture strength decreased and the toughness increased.

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N-type 고효율 태양전지용 Boron Diffused Layer의 형성 방법 및 특성 분석 (Boron Diffused Layer Formation Process and Characteristics for High Efficiency N-type Crystalline Silicon Solar Cell Applications)

  • 심경배;박철민;이준신
    • 한국전기전자재료학회논문지
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    • 제30권3호
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    • pp.139-143
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    • 2017
  • N-type crystalline silicon solar cells have high metal impurity tolerance and higher minority carrier lifetime that increases conversion efficiency. However, junction quality between the boron diffused layer and the n-type substrate is more important for increased efficiency. In this paper, the current status and prospects for boron diffused layers in N-type crystalline silicon solar cell applications are described. Boron diffused layer formation methods (thermal diffusion and co-diffusion using $a-SiO_X:B$), boron rich layer (BRL) and boron silicate glass (BSG) reactions, and analysis of the effects to improve junction characteristics are discussed. In-situ oxidation is performed to remove the boron rich layer. The oxidation process after diffusion shows a lower B-O peak than before the Oxidation process was changed into $SiO_2$ phase by FTIR and BRL. The $a-SiO_X:B$ layer is deposited by PECVD using $SiH_4$, $B_2H_6$, $H_2$, $CO_2$ gases in N-type wafer and annealed by thermal tube furnace for performing the P+ layer. MCLT (minority carrier lifetime) is improved by increasing $SiH_4$ and $B_2H_6$. When $a-SiO_X:B$ is removed, the Si-O peak decreases and the B-H peak declines a little, but MCLT is improved by hydrogen passivated inactive boron atoms. In this paper, we focused on the boron emitter for N-type crystalline solar cells.

EULER-MARUYAMA METHOD FOR SOME NONLINEAR STOCHASTIC PARTIAL DIFFERENTIAL EQUATIONS WITH JUMP-DIFFUSION

  • Ahmed, Hamdy M.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제18권1호
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    • pp.43-50
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    • 2014
  • In this paper we discussed Euler-Maruyama method for stochastic differential equations with jump diffusion. We give a convergence result for Euler-Maruyama where the coefficients of the stochastic differential equation are locally Lipschitz and the pth moments of the exact and numerical solution are bounded for some p > 2.

CVD에 의한 알루미나 멤브레인의 표면개질에 관한 연구 (The Study on Surface Modification of Alumina Membrane by CVD)

  • 이동호;최두진;현상훈;고광백
    • 한국세라믹학회지
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    • 제32권12호
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    • pp.1349-1356
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    • 1995
  • The change of permeation mechanism from Knudsen diffusion to micropore diffusion was observed after CVD modification of an alumina-sol coated alumina support which was prepared by slip coating process. Permselectivities of He/N2, H2/N2, and CO2/N2 were 5.67, 5.02, and 1.44, respectively. These values were higher than those under Knudsen diffusion controlled region.

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양모의 저온 염색 소개 - Sirolan LTD Process from ICI (Low Temperature Dyeing Process by Intercellular diffusion through Cell Membrane Complex Modification of Wool. - Technology based on CSIRO and ICI)

  • 윤일남
    • 한국염색가공학회:학술대회논문집
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    • 한국염색가공학회 2001년도 추계학술발표회 논문집
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    • pp.3-11
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    • 2001
  • Fundamental studies at the CSIRO division of Wool technology and ICI on the diffusion of dyes into wool〔1,2〕have let to development of a new approach to wool dyeing. In this method, the cell membrane complex of wool is modified before dyeing by treatment under mildly alkaline conditions with a special chemicals. Wool pretreated with ethoxylated quaternary ammonium salt has an increased rate of dyebath exhaustion and dye penetration early in the dyeing cycle. This enables the treated material to be dyed below the boil for a similar time to the conventional cycle. This technique can be used on untreated and shrinkresist-treated wool and wool/nylon blends. In addition to good macro-levelness and excellent coverage of tippiness, the low temperature dyeing process give higher exhaustion levels of dyestuffs and insect-resist agent and hence cleaner effluent liquors, compared with conventional dyeing process. Low Temperature Dyeing process cause significantly less fiber damage than conventional way. The reduction in damage is reflected in improved processing performance of the dyed wool.

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Numerical simulation of diffusion in the stratified flow

  • Mizumoto N.;Kawamura T.
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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    • pp.255-256
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    • 2003
  • Simulations of atmospheric diffusion process under stable and unstable conditions were carried out using both numerical and experimental methods. Results from the previous study show that numerical simulation using 3-dimensional incompressible Navier-Stokes equation and density deviation are in good agreement with typical plume pattern. In this study, we use experimental data of temperature and wind profile obtained from a thermally stratified wind tunnel as initial conditions for numerical simulation and compare the results.

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ROBUST OPTIMAL PROPORTIONAL REINSURANCE AND INVESTMENT STRATEGY FOR AN INSURER WITH ORNSTEIN-UHLENBECK PROCESS

  • Ma, Jianjing;Wang, Guojing;Xing, Yongsheng
    • 대한수학회보
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    • 제56권6호
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    • pp.1467-1483
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    • 2019
  • This paper analyzes a robust optimal reinsurance and investment strategy for an Ambiguity-Averse Insurer (AAI), who worries about model misspecification and insists on seeking robust optimal strategies. The AAI's surplus process is assumed to follow a jump-diffusion model, and he is allowed to purchase proportional reinsurance or acquire new business, meanwhile invest his surplus in a risk-free asset and a risky-asset, whose price is described by an Ornstein-Uhlenbeck process. Under the criterion for maximizing the expected exponential utility of terminal wealth, robust optimal strategy and value function are derived by applying the stochastic dynamic programming approach. Serval numerical examples are given to illustrate the impact of model parameters on the robust optimal strategies and the loss utility function from ignoring the model uncertainty.