• 제목/요약/키워드: Monthly

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Assessing the Benefits of Incorporating Rainfall Forecasts into Monthly Flow Forecast System of Tampa Bay Water, Florida (하천 유량 예측 시스템 개선을 위한 강우 예측 자료의 적용성 평가: 플로리다 템파 지역 사례를 중심으로)

  • Hwang, Sye-Woon;Martinez, Chris;Asefa, Tirusew
    • Journal of The Korean Society of Agricultural Engineers
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    • v.54 no.4
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    • pp.127-135
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    • 2012
  • This paper introduced the flow forecast modeling system that a water management agency in west central Florida, Tampa Bay Water has been operated to forecast monthly rainfall and streamflow in the Tampa Bay region, Florida. We evaluated current 1-year monthly rainfall forecasts and flow forecasts and actual observations to investigate the benefits of incorporating rainfall forecasts into monthly flow forecast. Results for rainfall forecasts showed that the observed annual cycle of monthly rainfall was accurately reproduced by the $50^{th}$ percentile of forecasts. While observed monthly rainfall was within the $25^{th}$ and $75^{th}$ percentile of forecasts for most months, several outliers were found during the dry months especially in the dry year of 2007. The flow forecast results for the three streamflow stations (HRD, MB, and BS) indicated that while the 90 % confidence interval mostly covers the observed monthly streamflow, the $50^{th}$ percentile forecast generally overestimated observed streamflow. Especially for HRD station, observed streamflow was reproduced within $5^{th}$ and $25^{th}$ percentile of forecasts while monthly rainfall observations closely followed the $50^{th}$ percentile of rainfall forecasts. This was due to the historical variability at the station was significantly high and it resulted in a wide range of forecasts. Additionally, it was found that the forecasts for each station tend to converge after several months as the influence of the initial condition diminished. The forecast period to converge to simulation bounds was estimated by comparing the forecast results for 2006 and 2007. We found that initial conditions have influence on forecasts during the first 4-6 months, indicating that FMS forecasts should be updated at least every 4-6 months. That is, knowledge of initial condition (i.e., monthly flow observation in the last-recent month) provided no foreknowledge of the flows after 4-6 months of simulation. Based on the experimental flow forecasts using the observed rainfall data, we found that the 90 % confidence interval band for flow predictions was significantly reduced for all stations. This result evidently shows that accurate short-term rainfall forecasts could reduce the range of streamflow forecasts and improve forecast skill compared to employing the stochastic rainfall forecasts. We expect that the framework employed in this study using available observations could be used to investigate the applicability of existing hydrological and water management modeling system for use of stateof-the-art climate forecasts.

Three-Way Balanced Multi-level Semi Rotation Sampling Designs

  • Park, You-Sung;Choi, Jai-Won;Kim, Kee-Whan
    • Proceedings of the Korean Statistical Society Conference
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    • 2002.05a
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    • pp.19-24
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    • 2002
  • The two-way balanced one-level rotation design has been discussed (Park, Kim and Choi, 2001), where the two-way balancing is done on interview time in monthly sample and rotation group. We extend it to three-way balanced multi-level design under the most general rotation system. The three-way balancing is accomplished on interview time not only in monthly sample and rotation group but also in recall time. We present the necessary condition and rotation algorithm which guarantee the three-way balancing. We propose multi-level composite estimators (MCE) from this design and derive their variances and mean squared errors (MSE), assuming the correlation from the measurements of the same sample unit and three types of biases in monthly sample.

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EVAPORATION DATA STOCHASTIC GENERATION FOR KING FAHAD DAM LAKE IN BISHAH, SAUDI ARABIA

  • Abdulmohsen A. Al-Shaikh
    • Water Engineering Research
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    • v.2 no.4
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    • pp.209-218
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    • 2001
  • Generation of evaporation data generally assists in planning, operation, and management of reservoirs and other water works. Annual and monthly evaporation series were generated for King Fahad Dam Lake in Bishah, Saudi Arabia. Data was gathered for period of 22 years. Tests of homogeneity and normality were conducted and results showed that data was homogeneous and normally distributed. For generating annual series, an Autoregressive first order model AR(1) was used and for monthly evaporation series method of fragments was used. Fifty replicates for annual series, and fifty replicates for each month series, each with 22 values length, were generated. Performance of the models was evaluated by comparing the statistical parameters of the generated series with those of the historical data. Annual and monthly models were found to be satisfactory in preserving the statistical parameters of the historical series. About 89% of the tested values of the considered parameters were within the assigned confidence limits

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Serological survey of Japanese encephalitis virus in domestic animals (축종별 일본뇌염바이러스에 대한 항체보유율 조사)

  • 이상준;정년기;송운재;장승익;하숙희;문병천;이필돈
    • Korean Journal of Veterinary Service
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    • v.26 no.1
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    • pp.11-18
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    • 2003
  • A total of 1,024 sera were collected from cattle(227), pigs(465), chickens(257) and dogs(75) raised or slaughtered in Daejeon metropolitan city from April to September 2002. Japanses encephalitis virus(JEV) antibodies in sera were detected by the haemagglutination inhibition test. The prevalence rates of JEV antibodies were 99.1 %, 54.0 %, 63.0 % and 98.7 % in cattle, pigs, chickens and dogs, respectively. In case of cattle and dogs, the monthly antibody-positive rates were as high as 85.7∼100.0 % and there were no differences among six months. In case of pigs, the monthly antibody-positive rate showed the lowest in April(6.4 %) and the highest in July(100.0 %) and it remained above 50 % during the summer-time. In case of chickens, the monthly antibody-positive rate was 100.0 % in July & August, 80.5 % in June, 40.0 % in May, 7.5 % in September and 5.0 % in April in order and there were distinct differences in seasons.

A Study of Adoption on the Concept of Monthly Probable Maximum Precipitation (월 PMP 개념의 적용에 관한 연구)

  • Choi, Han-Kyu;Kim, Nam-Won;Choi, Yong-Mook;Yoon, Hee-Sub
    • Journal of Industrial Technology
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    • v.21 no.B
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    • pp.241-248
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    • 2001
  • Normally at a flood season the operation of the dam depends on a short range weather forecast that makes many difficulties of the management at a dry season. It is needed to study the pattern of the long period rainfall. The concept of PMP(Probable Maximum Precipitation) was used for designing dam. From the concept, this study is applied the concept of monthly probable maximum precipitation for operating dam. It can be possible to let us know the appropriateness of a limiting water level at a rainy season. For the operation of dam at a dry season this study can predict roughly the flood season's pattern of precipitation by month or period, therfore the prediction of precipitation can rise efficient operation of a dam.

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A Study on Determination of Frequency Storage Capacities by Inflows (유입량에 따른 빈도별 저수용량 결정에 관한 연구)

  • Choi, Han-Kyu;Choi, Yong-Mook;Jeon, Kwang-Je
    • Journal of Industrial Technology
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    • v.20 no.A
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    • pp.131-138
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    • 2000
  • A past monthly data is not faithful so much for a short term. But, the stochastic generation technique was provide of a long-term data. Thus this study is used a data which generated a monthly inflow amounts data by Thomas-Fiering model. This model is needed a certain process which determination of distribution, decision of continuous durability, etc. It was generated a inflow data every one month as Thomas-Fiering method. The generated inflow data was used input data for a monthly cumulative analysis. This analysis obtained a storage capacities which would be required during droughts having various return periods. It was presented a equation of fitting regression that was carried out regression analysis of 5, 10, 20, 50 years period.

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COMPARISON OF TEMPERATURE DERIVED FROM THE MICROWAVE SOUNDING UNIT AND MONTHLY UPPER AIR DATA.

  • Hwang, Byong-Jun;Kim, So-Hyun;Chung, Hyo-Sang
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.491-495
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    • 1999
  • We compared the satellite observed temperature with the radiosonde observed temperature in the Korean Peninsula. The radiosonde observed data were obtained from four upper air observation stations in the Korean Peninsula from 1981 to 1998, and that was compared with the satellite observed data of the channel-2 and channel-4 of microwave sounding unit(MSU) on board NOAA series of polar-orbiting satellites. The radiosonde data were reconstructed into monthly radiosonde T$_{b}$ using MSU weighting function. The monthly climatology shows radiosonde T$_{b2}$ is higher than MSU T$_{b2}$ in summer. The correlation between MSU T$_{b2}$ and radiosonde T$_{b2}$ is 0.72-0.76 and 0.73-0.81 between MSU T$_{b4}$ and radiosonde T$_{b4}$.

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New Elderly Consumers' Fashion Innovativeness and Monthly Spending on Clothing : Focusing on Moderating Role of Materialism

  • Choo, Ho-Jung;Hong, Kyung-Hee;Moon, Hee-Kang
    • International Journal of Costume and Fashion
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    • v.10 no.1
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    • pp.47-66
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    • 2010
  • New elderly consumer market composed of consumers 50 years or older has both resemblance and difference with younger fashion market. This study aimed to examine the effect of socio-demographic and psychological factors on fashion innovativeness and monthly spending on clothing of new aged elderly consumers with the moderating role of materialism. The study found that socio-demographic factors tended to have direct effects on clothing spending, while psychographic factors have both direct effect and indirect effect through fashion innovativeness. The mediating role of fashion innovativeness in predicting clothing spending was found to be moderated by materialism of new elderly consumers. Marketing implications and limitations were discussed.

An Innovative Application Method of Monthly Load Forecasting for Smart IEDs

  • Choi, Myeon-Song;Xiang, Ling;Lee, Seung-Jae;Kim, Tae-Wan
    • Journal of Electrical Engineering and Technology
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    • v.8 no.5
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    • pp.984-990
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    • 2013
  • This paper develops a new Intelligent Electronic Device (IED), and then presents an application method of a monthly load forecasting algorithm on the smart IEDs. A Multiple Linear Regression (MLR) model implemented with Recursive Least Square (RLS) estimation is established in the algorithm. Case Study proves the accuracy and reliability of this algorithm and demonstrates the practical meanings through designed screens. The application method shows the general way to make use of IED's smart characteristics and thereby reveals a broad prospect of smart function realization in application.

Capacity Planning and Control of Probe Process in Semiconductor Manufacturing (반도체 Probe 공정에서의 생산 능력 계획)

  • Jeong, Bong-Ju;Lee, Young-Hoon
    • IE interfaces
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    • v.10 no.1
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    • pp.15-22
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    • 1997
  • In semiconductor manufacturing, the probe process between fabrication and assembly process is constrained mostly by the equipment capacity because most products pass through the similar procedures. The probe process is usually performed in a batch mode with relatively short cycle times. The capability of the probe process can be determined by the optimal combination of the equipments and the products. A probe line usually has several types of equipment with different capacity. In this study, the probe line is modeled in terms of capacity to give the efficient planning and control procedure. For the practical usage, the hierarchical capacity planning procedure is used. First, a monthly capacity plan is made to meet the monthly production plan of each product. Secondly, the daily capacity planning is performed by considering the monthly capacity plan and the daily fabrication output. Simple heuristic algorithms for daily capacity planning are developed and some experimental results are shown.

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