Impact of planning horizon on water distribution network design

Abstract The continuous expansion of Water Distribution Network (WDN) makes its design a dynamic process performed within many planning horizons. An appropriate planning horizon is important to save costs and avoid over-design. Typically, a master plan is practiced around every 20 years. The complexity of WDN and computational demands have prevented a full network study of the impact of planning horizon on system cost and efficiency. In this paper, a dynamic network model was employed to simulate the growth of WDN under different growth patterns (exponential and linear) and planning horizons to explore the optimum planning horizon under different interest rates. It is found that the choice of the optimum (i.e. least costly) planning horizon is sensitive to the interest rate. For both growth patterns, a shorter planning horizon is favored with higher annual interest rates while a longer planning horizon is favored with lower rates. With the same interest rate, exponential growth pattern generally favors a shorter planning horizon than linear growth pattern due to more excess capacity provided at the beginning of the study period. The optimum planning horizon is longer than 20 years when interest rate is lower than 3.0% for linear growth or 2.0% for exponential growth.

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Water-Demand Growth Modelling in Puerto Ayora’s Water Distribution Network Using EPANET

International Journal of World Policy and Development Studies ◽

10.32861/ijwpds.58.71.81 ◽

2019 ◽

pp. 71-81

Author(s):

María Reyes ◽

Nemanja Trifunović ◽

Saroj Sharma ◽

Maria Kennedy

Keyword(s):

Water Supply ◽

Water Demand ◽

Water Distribution ◽

Water Distribution Network ◽

Planning Horizon ◽

Growth Modelling ◽

Hydraulic Characteristics ◽

Demand Growth ◽

Moderate Growth ◽

The Town

This paper elaborates the hydraulic characteristics of the water supply network of the town of Puerto Ayora. First, it intends to replicate the household individual storage by simulating nodal tanks with the use of the EPANET software. Later, it uses the Pressure-Driven Approach (PDA) to develop a methodology that estimates the overflow of storage facilities, one of the main sources of wastage in Puerto Ayora. Finally, it uses the Demand-Driven Approach (DDA), with the aim of assessing the network in the future, under four population growth scenarios. With the chosen moderate growth scenario, two options are suggested in order to tackle the water supply issues at the end of the planning horizon.

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Income Tax Aspects of Liquidation in Multiperiod Linear Growth Models

Journal of Agricultural and Applied Economics ◽

10.1017/s0081305200014333 ◽

1978 ◽

Vol 10 (2) ◽

pp. 29-34 ◽

Cited By ~ 1

Author(s):

Donald W. Reid ◽

Wesley N. Musser ◽

Neil R. Martin

Keyword(s):

Linear Programming ◽

Firm Growth ◽

Linear Growth ◽

Growth Models ◽

Optimal Growth ◽

Planning Horizon ◽

Growth Patterns ◽

Net Worth ◽

Programming Framework ◽

On Farm

Since the mid-1960s, agricultural economists have given much attention to research on farm-firm growth. One procedure used in this type of research has been multiperiod linear programming models, e.g. [1, 6, 9, 11, 14, 17]. Several researchers using the multiperiod linear programming framework have compared optimizing criteria. Generally, comparisons were made between maximizing some type of present value criterion and maximizing net worth at the end of the planning horizon. The different assumptions associated with the two maximizing criteria have resulted in different optimal growth patterns.

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Serial volumetric assessment of the natural history and growth pattern of incidentally discovered meningiomas

Journal of Neurosurgery ◽

10.3171/2008.8.jns08481 ◽

2009 ◽

Vol 110 (4) ◽

pp. 675-684 ◽

Cited By ~ 77

Author(s):

Tetsuo Hashiba ◽

Naoya Hashimoto ◽

Shuichi Izumoto ◽

Tsuyoshi Suzuki ◽

Naoki Kagawa ◽

...

Keyword(s):

Regression Analysis ◽

Natural History ◽

Tumor Growth ◽

Exponential Growth ◽

Growth Pattern ◽

Linear Growth ◽

Growth Patterns ◽

Surgical Removal ◽

Volumetric Assessment

Object Due to advances in neuroimaging and the increasing use of imaging to screen for brain disease (“brain checkups”), meningiomas are now often detected as an incidental finding. The natural history of these asymptomatic meningiomas remains unclear, however. In this study, the authors investigated the natural history and growth pattern of incidentally detected meningiomas using serial volumetric assessment and regression analysis. Methods In 70 patients with incidentally discovered meningiomas who underwent follow-up for longer than 1 year, tumor volumes were calculated volumetrically at each follow-up visit, and tumor growth was determined. In patients with tumor growth, regression analysis was performed to determine the pattern of growth. Results Forty-four tumors exhibited growth and 26 did not. In a regression analysis, 16 of the tumors that grew followed an exponential growth pattern and 15 exhibited linear growth patterns. The presence of calcification was the only imaging characteristic that significantly distinguished the group with tumor growth from that without, although no radiological characteristics significantly distinguished the exponential growth group from the linear growth group. Two patients with obvious tumor growth underwent surgical removal and the pathological specimens extracted showed a high proliferative potential. Conclusions The authors found that incidentally discovered meningiomas did not always follow an exponential growth pattern but often exhibited more complex patterns of growth. Serial monitoring of tumor volumes and regression analysis may reveal the growth pattern of incidental meningiomas and provide information useful for determining treatment strategy.

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The first month of the COVID-19 outbreak in 46 sub-Saharan African countries. A comparative analysis of growth rates

10.1101/2020.04.09.20057091 ◽

2020 ◽

Author(s):

Martin J. Prince ◽

Atalay Alem ◽

Dixon Chibanda ◽

Lara Fairall ◽

Abebaw Fekadu ◽

...

Keyword(s):

Critical Care ◽

Growth Rates ◽

Exponential Growth ◽

Linear Growth ◽

Growth Patterns ◽

European Countries ◽

World Health ◽

African Countries ◽

Sub Saharan ◽

Doubling Times

ABSTRACTBackgroundThe COVID-19 outbreak in sub-Saharan African countries started after those in Asia, Europe and North America, on 28th February 2020. The susceptibility to infection of populations in that region has been debated. Outbreaks on the scale of those seen elsewhere would pose substantial challenges. There are reasons for concern that transmission may be high and difficult to control, rapidly exceeding capacity to meet the needs for hospitalization and critical care.MethodsWe obtained data on daily new confirmed cases for all 46 countries from the World Health Organization, and used these to model and visualize growth trajectories using an AutoRegressive Integrated Moving Average (ARIMA) model. We then estimated doubling times from growth rates estimated from Poisson regression models, and by back counting from the most recent observation. We also calculated the time from 1st to 50th case, and the time from 5th to 100th case. These indicators were compared with the same summary indicators of growth at the same stage of the outbreak in highly affected European countries.ResultsKenya was the only country with clear evidence of exponential growth. Nineteen countries had either reported no cases, were in the first few days of the outbreak, or had reported fewer than 10 cases over a period of two or more weeks. For the remaining 27 countries we identified four growth patterns: slow linear growth, more rapid linear growth, variable growth patterns over the course of the outbreak, and early signs of possible exponential growth. For those in the last three groups, doubling times ranged from 3 to 4 days, times from 1st to 50th case from 12 to 29 days, and from 5th to 100th case from eight to 15 days. These early indicators are comparable to those in European countries that have gone on to have substantial outbreaks, and time to 50th case was shorter suggesting lesser effectiveness of contact-tracing and quarantine in the early phase.ConclusionThe 46 sub-Saharan African countries, home to over one billion people, are at a tipping point with clear potential for the outbreak to follow a similar course as in HIC in the global north. Radical population-level physical distancing measures may be required, but their impact on poor, disadvantaged and vulnerable people and communities need mitigating. Health systems in the region need urgent technical and material support, with testing, personal protection, and hospital/ critical care.

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Pseudo-exponential growth in length of the fission yeast, Schizosaccharomyces pombe

Canadian Journal of Microbiology ◽

10.1139/m88-235 ◽

1988 ◽

Vol 34 (12) ◽

pp. 1338-1343 ◽

Cited By ~ 11

Author(s):

Hisao Miyata ◽

Machiko Miyata ◽

Byron F. Johnson

Keyword(s):

Schizosaccharomyces Pombe ◽

Fission Yeast ◽

Exponential Growth ◽

Linear Growth ◽

Normal Growth ◽

Growth Patterns ◽

Birth Length ◽

Yeast Cells ◽

Wild Type ◽

Constant Length

The growth patterns of individual cells of the fission yeast (Schizosaccharomyces pombe wild-type cells, strain 972 h−; cells exposed to hydroxyurea; and cdc mutants, 11-123, 2-33) were investigated by time-lapse photomicrography. Wild-type cells showed one, two, or three linear-growth segments followed by a constant-length stage. Cells with two segments were most frequent. Hydroxyurea cells that divided as oversized cells (about three times the birth length) had three linear-growth segments in a cycle. Mutant cdc11-123 cells did not divide but had a constant-length stage separating the cycles; both the first and second cycles consisted of two linear-growth segments, and cells were oversized at the second constant-length stage (about 3.5 times the birth length). Elongating cdc2-33 cells that did not divide and were oversized (about five times the birth length) while under observation, showed four linear-growth segments. Cells of all strains showed 30 to 40% increase in growth rate at the rate-change point and maintained approximate exponential (pseudo-exponential) growth. We conclude that the normal growth pattern of individual fission-yeast cells is the pseudo-exponential pattern.

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Decision analysis for determining the optimum planning horizon in aggregate production planning: Part 2: Difference between planning horizons in weekly and in monthly schedulings

International Journal of Production Research ◽

10.1080/00207548508904718 ◽

1985 ◽

Vol 23 (2) ◽

pp. 423-436 ◽

Cited By ~ 4

Author(s):

HIROYUKI NAGASAWA ◽

NORIYUKI NISHIYAMA ◽

KATSUNDO HITOMI

Keyword(s):

Decision Analysis ◽

Production Planning ◽

Planning Horizon ◽

Aggregate Production Planning ◽

Aggregate Production ◽

Optimum Planning ◽

Planning Horizons

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Economic effects of monetary policy in Russia: What do large datasets tell us?

Voprosy Ekonomiki ◽

10.32609/0042-8736-2020-4-31-53 ◽

2020 ◽

pp. 31-53 ◽

Cited By ~ 1

Author(s):

Anna A. Pestova ◽

Natalia A. Rostova

Keyword(s):

Monetary Policy ◽

Interest Rate ◽

Interest Rates ◽

Economic Activity ◽

Global Financial Crisis ◽

Exchange Rate Regime ◽

Aggregate Demand ◽

Economic Effects ◽

Theoretical Concepts ◽

Empirical Estimates

Is the Bank of Russia able to control inflation and, at the same time, manage aggregate demand using its interest rate instruments? In other words, are empirical estimates of the effects of monetary policy in Russia consistent with the theoretical concepts and experience of advanced economies? This paper is aimed at addressing these issues. Unlike previous research, we employ “big data” — a large dataset of macroeconomic and financial data — to estimate the effects of monetary policy in Russia. We focus exclusively on the period after the 2008—2009 global financial crisis when the Bank of Russia announced the abandoning of its fixed ruble exchange rate regime and started to gradually transit to an interest rate management. Our estimation results do not confirm standard responses of key economic activity and price variables to tightening of monetary policy. Specifically, our estimates do not reveal a statistically significant restraining effect of the Bank of Russia’s policy of high interest rates on inflation in recent years. At the same time, we find a significant deteriorating effect of the monetary tightening on economic activity indicators: according to our conservative estimates, each of the key rate increases occurred in March and December 2014 had led to a decrease in the industrial production index by about 0.2 percentage points within a year.

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DETERMINAN INFLASI DI INDONESIA PERIODE 1980-2015

Jurnal Ekonomi dan Bisnis ◽

10.24123/jeb.v21i1.1631 ◽

2016 ◽

Vol 21 (1) ◽

pp. 1-7

Author(s):

Risna Risna

Keyword(s):

Interest Rate ◽

Interest Rates ◽

Money Supply ◽

Government Spending ◽

Positive Impact ◽

Secondary Data ◽

Quantitative Approach ◽

State Spending ◽

Factors Affecting ◽

The Interest Rate

This study aims to determine the effect of government spending, the money supply, the interest rate of Bank Indonesia against inflation.This study uses secondary data. Secondary data were obtained directly from the Central Bureau of Statistics and Bank Indonesia. It can be said that there are factors affecting inflationas government spending, money supply, and interest rates BI. The reseach uses a quantitative approach to methods of e-views in the data. The results of analysis of three variables show that state spending significantand positive impact on inflationin Indonesia, the money supply significantand negative to inflationin Indonesia, BI rate a significantand positive impact on inflation in Indonesia

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