• Title/Summary/Keyword: Demand estimation

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Volume Estimation Method for Greenhouse Rainwater Tank (온실 빗물 저수조의 용량산정 방법)

  • Seo, Chan Joo;Koo, Ja-Kong
    • Journal of the Korea Organic Resources Recycling Association
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    • v.24 no.2
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    • pp.31-39
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    • 2016
  • Due to the temporal variation of inflow/outflow, the water tank is needed. For the calculation of water tank capacity, the absolute difference between cumulative amounts of supply(e.g., rainfall) and demand(e.g.,watering) is used. No matter the (-) and (+) the absolute maximum capacity of the subtraction is calculated as the capacity. In this paper, using rainfall and watering of greenhouse facilities, it is proved that the non-linear supply or demand can be applied, and it is proved also that the greater non-linear variation case. And as the time interval for monitoring is decreased, the basin or tank volume are increased, with approximately 10 days as the critical monitoring interval for the annual natural rainfall event.

Analysis of Demands of Manpower in Southwest Marine Tourism (서.남해안권 관광벨트의 해양관광레저인력 수요 분석)

  • Park, Chang-Kyu
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.13 no.4
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    • pp.87-93
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    • 2007
  • Tourists' needs are changing rapidly and new niche markets, such as nature tourism, eco-tourism, and marine tourism, are flourishing in response to consumer demand. Especially, the estimating demand & supply of manpower in marine tourism is a very important issue for basic tourism HRD policy. This research is focused on the estimation of growing demands of manpower and suggests the method to estimate the proper number of manpower in marine tourism industry.

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Development of Station Dwelling Time Estimation Model for Seoul Metro Line No. 4 (도시철도 정차시간 분석을 통한 모형식 개발에 관한 연구 (서울시 도시철도 4호선을 중심으로))

  • Park, Jeong-Su;Sin, Dong-Hui;Won, Je-Mu
    • Journal of Korean Society of Transportation
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    • v.24 no.2 s.88
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    • pp.147-156
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    • 2006
  • Metropolitan Subway, tke volume of station, distance between station is short. when the demand is concentrated during moving peak periods, the Headway that than Line Headway in which Station Headway is applied to Station Capacity computation be. The factors to determine the Station Headway have a fixing Price of the machine and the Dwell time. Other factors aye decided already or fixing price but the Dwell time that change according to demand cause the biggest effect at Station Headway. After analyze constituents that influence to Station Headway in this study calculated correct Station Capacity drawing estimating dwell time model that change according to demand.

A Study on the Regional Property for the Agricultural Water Demand (농업용수 수요량의 지역적 특성 조사 연구(관개배수 \circled1))

  • 김선주;이광야;여운식;박재흥
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2000.10a
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    • pp.120-125
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    • 2000
  • This study analyzes agricultural water demand nationwide which calculated by the estimation system for agricultural water demand(ESAD) with the data are observed in the other Studies. The results are as follows. Maximum, minimum and average values of annual evapotranspiration in paddy in 1,767 boundaries covering all the country are estimated as 819.2mm, 595.2mm and 702.9mm respectively. In the case of transplant seeding, the annual effective rainfall is estimated as 834.7mm to 464.3mm, while the average is 635.3mm. The amount of effective rainfall is largest in case of transplant seedlings and then come watered direct seeding and dry direct seeding regardless of region. Maximum, minimum and average values of annual evapotranspiration in upland in 1,767 boundaries are estimated as 659.97mm, 129.3mm and 411.8mm respectively. The annual effective rainfall is estimated as 607.2mm to 68.3mm while the average is 257.4mm. infiltration ratio in paddy in 1,767 boundaries applied in ESAD is 5.06mm/day in average, varying from 12.0mm/day to 2.0mm/day. Applied conveyance loss is 12.8% in average, varying from 18.0% to 8.0%.

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A Simple Power Management Scheme with Enhanced Stability for a Solar PV/Wind/Fuel Cell Fed Standalone Hybrid Power Supply using Embedded and Neural Network Controller

  • Thangavel, S.;Saravanan, S.
    • Journal of Electrical Engineering and Technology
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    • v.9 no.5
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    • pp.1454-1470
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    • 2014
  • This paper propose a new power conditioner topology with intelligent power management controller that integrates multiple renewable energy sources such as solar energy, wind energy and fuel cell energy with battery backup to make best use of their operating characteristics and obtain better reliability than that could be obtained by single renewable energy based power supply. The proposed embedded controller is programmed for maintaining a constant voltage at PCC, maximum power point tracking for solar PV panel and WTG and power flow control by regulating the reference currents of the controller on instantaneous basis based on the power delivered by the sources and load demand. Instantaneous variation in reference currents of the controller enhances the controller response as it accommodates the effect of continuously varying solar insolation and wind speed in the power management. The power conditioner uses a battery bank with embedded controller based online SOC estimation and battery charging system to suitably sink or source the input power based on the load demand. The simulation results of the proposed power management system for a standalone solar/WTG/fuel cell fed hybrid power supply with real time solar radiation and wind velocity data collected from solar centre, KEC for a sporadically varying load demand is presented in this paper and the results are encouraging in reliability and stability perspective.

Recommended Practice for Demand Factor/Diversity Factor with respect to Power Consumption Characteristics in Commercial Buildings (업무용 빌딩의 전력소비 특성을 고려한 수용률/부등률의 적용에 관한 연구)

  • 김세동
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.16 no.6
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    • pp.74-79
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    • 2002
  • This paper shows a reasonable design standard factor in commercial buildings, that was made by the systematic and statistical way considering actual conditions, such as investigated electric equipment capacity, electric power consumption, load characteristic, etc., for 23 commercial buildings. With a rapid growth of national economics with the development of intelligence society , electrical energy consumption markedly increased Expecially, it is increased electrical energy consumption in the commercial buildings and thus an energy conservation through efficient use of electricity became more important In our country, the estimation of demand factor and electric equipment capacity are not properly and thus the application of these factors are confusing and different in each electric design of the field.

A Case Study of Sustainable Potential of Rainwater System Development for Household Water Consumption in Nigeria (지속가능한 생활용 우수시스템 개발 사례)

  • Adelodun, Bashir;Choi, Kyung-Sook
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.485-485
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    • 2018
  • Rainwater harvesting system (RWH) can provide a relief for the household and farmers especially in areas with intense water scarcity during the long lull of rainy season. However, much attention has not been given to this alternative water source in Nigeria. This paper estimates the per capita water demand for 1,950 inhabitants and rainwater potential in Ojonbodu Estate, Oyo State, Nigeria, using data from detailed questionnaires, water consumption calculator software, and 20-year rainfall data. The potential rainwater estimation was based on amount of precipitation, size of catchment and runoff coefficient. Consequently, using estimated values of $39420m^3$ and $6.5114{\times}10^7m^3$ for per capita consumption and potential rainwater respectively, the rainwater harvesting system was designed for rainwater collection, and storage. The harvested rainwater was $450, 000m^3$ with collection efficiency of 69.16 %, which exceeded the household water consumption requirement. Thus, the harvested rainwater was able to meet the estimated water demand of the Ojonbodu Estate households during the period of water scarcity.

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Effect of Social Norm on Consumer Demand: Multiple Constraint Approach

  • Choi, Sungjee;Nam, Inwoo;Kim, Jaehwan
    • Asia Marketing Journal
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    • v.22 no.1
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    • pp.41-60
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    • 2020
  • The goal of the study is to understand the role of social norm in purchase decisions where demand is revealed in the form of multiple-discreteness. Consumers are socially engaged in various activities through the expectation from others in their community. Actions or decisions are likely to reflect this influence. This implicit or explicit social norm is revealed as the rules, regulations, and standards that are understood, shared, endorsed, and expected by group members. When consumers' decisions are in distance from the norm, they come to face discomfort such as shame, guilt, embarrassment, and anxiety. These pressure act as a constraint as opposed to utility in their decision making. In this study, the effect of social norms on consumer demand is captured via multiple constraint model where constraints are not only from budget equation but also from psychological burden induced by the deviation from the norm. The posterior distributions of model parameters were estimated via conjoint study allowing for heterogeneity via hierarchical Bayesian framework. Individual characteristics such as age, gender and work experience are also used as covariates for capturing the observed heterogeneity. The empirical results show the role of social norm as constraint in consumers' utility maximization. The proposed model accounting for social constraint outperforms the standard budget constraint-only model in terms of model fit. It is found that people with longer job experience tend to be more robust and resistant to the deviation from the norm. Incorporating social norm into the utility model allows for another means to disentangle the reason for no-purchase as 'not preferred' and 'not able to buy'.

Unbiasedness or Statistical Efficiency: Comparison between One-stage Tobit of MLE and Two-step Tobit of OLS

  • Park, Sun-Young
    • International Journal of Human Ecology
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    • v.4 no.2
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    • pp.77-87
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    • 2003
  • This paper tried to construct statistical and econometric models on the basis of economic theory in order to discuss the issue of statistical efficiency and unbiasedness including the sample selection bias correcting problem. Comparative analytical tool were one stage Tobit of Maximum Likelihood estimation and Heckman's two-step Tobit of Ordinary Least Squares. The results showed that the adequacy of model for the analysis on demand and choice, we believe that there is no big difference in explanatory variables between the first selection model and the second linear probability model. Since the Lambda, the self- selectivity correction factor, in the Type II Tobit is not statistically significant, there is no self-selectivity in the Type II Tobit model, indicating that Type I Tobit model would give us better explanation in the demand for and choice which is less complicated statistical method rather than type II model.

Analysis of the Competitiveness of Broadband over Power Line Communication in Korea

  • Jeong, Gi-Cheol;Koh, Dae-Young;Lee, Jong-Su
    • ETRI Journal
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    • v.30 no.3
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    • pp.469-479
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    • 2008
  • This study analyzes factors affecting the competitiveness of broadband over power line communication (BPLC) and predicts demand for the service, based on quantitative information about consumer preferences drawn from a survey of Korean consumers. Findings from the estimation suggest that, although consumers value some beneficial features of BPLC, to be competitive the speed and stability of its data transmission needs to be improved. Moreover, on the basis of a market simulation, we expect BPLC to occupy only a small portion of Korea's Internet access market in the future, a finding we expect would hold true for other developed countries whose Internet access markets are already mature.

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