• Title/Summary/Keyword: sacramento

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A Study on Regionalization of Parameters for Sacramento Continuous Rainfall-Runoff Model Using Watershed Characteristics (유역특성인자를 활용한 Sacramento 장기유출모형의 매개변수 지역화 기법 연구)

  • Kim, Tae-Jeong;Jeong, Ga-In;Kim, Ki-Young;Kwon, Hyun-Han
    • Journal of Korea Water Resources Association
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    • v.48 no.10
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    • pp.793-806
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    • 2015
  • The simulation of natural streamflow at ungauged basins is one of the fundamental challenges in hydrology community. The key to runoff simulation in ungauged basins is generally involved with a reliable parameter estimation in a rainfall-runoff model. However, the parameter estimation of the rainfall-runoff model is a complex issue due to an insufficient hydrologic data. This study aims to regionalize the parameters of a continuous rainfall-runoff model in conjunction with a Bayesian statistical technique to consider uncertainty more precisely associated with the parameters. First, this study employed Bayesian Markov Chain Monte Carlo scheme for the estimation of the Sacramento rainfall-runoff model. The Sacramento model is calibrated against observed daily runoff data, and finally, the posterior density function of the parameters is derived. Second, we applied a multiple linear regression model to the set of the parameters with watershed characteristics, to obtain a functional relationship between pairs of variables. The proposed model was also validated with gauged watersheds in accordance with the efficiency criteria such as the Nash-Sutcliffe efficiency, index of agreement and the coefficient of correlation.

A Novel Air Indexing Scheme for Window Query in Non-Flat Wireless Spatial Data Broadcast

  • Im, Seok-Jin;Youn, Hee-Yong;Choi, Jin-Tak;Ouyang, Jinsong
    • Journal of Communications and Networks
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    • v.13 no.4
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    • pp.400-407
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    • 2011
  • Various air indexing and data scheduling schemes for wireless broadcast of spatial data have been developed for energy efficient query processing. The existing schemes are not effective when the clients' data access patterns are skewed to some items. It is because the schemes are based on flat broadcast that does not take the popularity of the data items into consideration. In this paper, thus, we propose a data scheduling scheme letting the popular items appear more frequently on the channel, and grid-based distributed index for non-flat broadcast (GDIN) for window query processing. The proposed GDIN allows quick and energy efficient processing of window query, matching the clients' linear channel access pattern and letting the clients access only the queried data items. The simulation results show that the proposed GDIN significantly outperforms the existing schemes in terms of access time, tuning time, and energy efficiency.

A Prediction of Behavior of Granular Soils Based on the Advanced Elasto Plastic Model (개선된 탄.소성 구성모델을 이용한 사질토의 응력-변형률 거동예측)

  • Park, Byeong-Gi;Im, Seong-Cheol;Lee, Gang-Il
    • Geotechnical Engineering
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    • v.11 no.3
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    • pp.81-90
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    • 1995
  • Based on the close investigation of Lade elasto -plastic model, this study proposes a new elasto -plastic constitutive model for foundation composed of granular soils. The new model contains 1st stress invariant in plastic potential function as well as yield function, which is different from Lade original model. Both these functions called a correction function include a correction term. To validate the new analytical model, it was compered with some previous models. Comparison between the test results and numerical results using Lade and new model was carried out concerning Sacramento River sand, U.S.A and Backma River sand. The conclusion was obtained that more refined model well be deft.eloped throughout this research.

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Runoff Analysis on the Physically-Based Conceptual Time-Continuous Runoff Model (물리적.개념적 연속 유출모형에 의한 유출해석)

  • 배덕효;조원철
    • Water for future
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    • v.28 no.6
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    • pp.193-202
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    • 1995
  • The subjective research attempts to apply a rainfall-runoff model capable of considering time-variation of soil water contents which are highly correlated to the river flows on the qpqyungchang river basin and to evaluate its performance for flow forecasting. The model used in this study is a physically-based conceptual time-continuous model, which is composed of the Sacramento soil moisture accounting model and the nonlinear multiple conceptual reservoirs model. The daily precipitation and evaporation data for 7 years and for 3 years were used for the parameter estimation and the model verification, respectively. As a result, the flows including a significant flood event were well simulated, and the cross-correlation coefficient between observed flows and computed flows for the verification periods was 0.87, but in general computed flows were underestimated for the low-flow periods. Also, the effects of precipitation and soil water content to the river flows were analysed for the flood and the drought.

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Survey and Economic Analysis of Food Industry Residues for Biomass-to-energy Conversion in Merced and Stanislaus Counties, California, USA (바이오에너지로의 전환을 위한 캘리포니아 식품가공공장 오.폐수 특성 조사 및 경제성 분석)

  • Kim, Dae-Hyun
    • Journal of Biosystems Engineering
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    • v.34 no.4
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    • pp.243-253
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    • 2009
  • This research expands investigations into the biomass resource potential associated with California's food processing industry by surveying industries within a two county region in the San Joaquin Valley, California, USA. A previous survey conducted in 2005 for the Sacramento Municipal Utility District (SMUD) quantified residue and waste generation from food processors and food preparation businesses in the Sacramento region. The present survey investigates residue and waste streams from food processors located in Merced and Stanislaus Counties. Sixty food processors were identified to participate in the survey, of which 49 responded (82%) and data were acquired for 38 (63%) (6 facilities closed or moved, 8 decided not to participate). Within the two counties, total annual waste among survey respondents amounted to 24,044 dry tons of high moisture (${\geq}$60%) food residuals, 5,358 dry tons of low moisture (<60%) food residuals; and 23.7 million $m^3$ of wastewater containing 38,814 tons of biochemical oxygen demand ($BOD_5$). The total potential electric power generation from these food residues was estimated at approximately $7\;MW_e$. Total solid waste resource included in the survey response was estimated at about 10% of statewide residue generation for processors falling within the Standard Industrial Classification (SIC) System Major Group 20 (Food and Kindred Products) categories.

THE PRESENCE OF $C_2$ LINES IN SUNSPOTS

  • Yun, Hong-Sik;Beebe, H.A.;Baggett, W.E.
    • Journal of The Korean Astronomical Society
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    • v.15 no.1
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    • pp.37-39
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    • 1982
  • High spatial and spectral resolution observations have been made over a sunspot (SPO 6403) with the Echelle Spectrograph at the Vacuum Tower Telescope, Sacramento Peak Observatory. Our observed spectra, scanned with SPO's fast microdensitometer, clearly show strengthening of $C_2$ lines in the penumbra relative to the photosphere and much weakening in the umbra in agreement with the predictions made by our molecular equilibrium calculations (Lee et al. 1981).

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Intercepting Filter Approach to Injection Flaws

  • Salem, Ahmed
    • Journal of Information Processing Systems
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    • v.6 no.4
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    • pp.563-574
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    • 2010
  • The growing number of web applications in the global economy has made it critically important to develop secure and reliable software to support the economy's increasing dependence on web-based systems. We propose an intercepting filter approach to mitigate the risk of injection flaw exploitation- one of the most dangerous methods of attacking web applications. The proposed approach can be implemented in Java or .NET environments following the intercepting filter design pattern. This paper provides examples to illustrate the proposed approach.