scholarly journals Planning renewal of water mains while considering deterioration, economies of scale and adjacent infrastructure

2010 ◽  
Vol 10 (6) ◽  
pp. 897-906 ◽  
Author(s):  
Yehuda Kleiner ◽  
Amir Nafi ◽  
Balvant Rajani
Keyword(s):  
Cathodic Protection ◽  
Economies Of Scale ◽  
Poisson Model ◽  
Pipe Material ◽  
Efficient Manner ◽  
Structural Deterioration ◽  
Dynamic Factors ◽  
Water Mains ◽  
Subsequent Failure

The structural deterioration of water mains and their subsequent failure are affected by many factors, both static (e.g., pipe material, pipe size, age (vintage), soil type) and dynamic (e.g., climate, cathodic protection, pressure zone changes). This paper describes a non-homogeneous Poisson model developed for the analysis and forecast of breakage patterns in individual water mains, while considering both static and dynamic factors. Subsequently, these forecasted breakage patterns are used to schedule the renewal of water mains in an economically efficient manner, while considering the various associated costs, including economies of scale and scheduled works on adjacent infrastructure. In this paper, he principles of the approach are described briefly and its application is demonstrated with the help of a case study.

scholarly journals I-WARP: Individual Water mAin Renewal Planner

2010 ◽  
Vol 3 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Y. Kleiner ◽  
B. Rajani
Keyword(s):  
Research Council ◽  
National Research Council ◽  
Water Utilities ◽  
Pipe Material ◽  
Mathematical Approach ◽  
Structural Deterioration ◽  
Dynamic Factors ◽  
Water Mains ◽  
Subsequent Failure

Abstract. I-WARP is based upon a nonhomogeneous Poisson approach to model breakage rates in individual water mains. The structural deterioration of water mains and their subsequent failure are affected by many factors, both static (e.g., pipe material, pipe size, age (vintage), soil type) and dynamic (e.g., climate, cathodic protection, pressure zone changes). I-WARP allows for the consideration of both static and dynamic factors in the statistical analysis of historical breakage patterns. This paper describes the mathematical approach and demonstrates its application with the help of a case study. The research project within which I-WARP was developed, was jointly funded by the National Research Council of Canada (NRC), and the Water Research foundation (formerly known as the American Water Works Association Research Foundation – AwwaRF) and supported by water utilities from USA and Canada.

scholarly journals I-WARP: individual water main renewal planner

2010 ◽  
Vol 3 (1) ◽  
pp. 25-41 ◽  
Author(s):  
Y. Kleiner ◽  
B. Rajani
Keyword(s):  
Research Council ◽  
National Research Council ◽  
Water Utilities ◽  
Pipe Material ◽  
Mathematical Approach ◽  
Structural Deterioration ◽  
Dynamic Factors ◽  
Water Mains ◽  
Subsequent Failure

Abstract. I-WARP is based upon a nonhomogeneous Poisson approach to model breakage rates in individual water mains. The structural deterioration of water mains and their subsequent failure are affected by many factors, both static (e.g., pipe material, pipe size, age (vintage), soil type) and dynamic (e.g., climate, cathodic protection, pressure zone changes). I-WARP allows for the consideration of both static and dynamic factors in the statistical analysis of historical breakage patterns. This paper describes the mathematical approach and demonstrates its application with the help of a case study. The research project within which I-WARP was developed, was jointly funded by the National Research Council of Canada (NRC), and the Water Research foundation (formerly known as the American Water Works Association Research Foundation – AwwaRF) and supported by water utilities from USA and Canada.

scholarly journals Comparison of four models to rank failure likelihood of individual pipes

2011 ◽  
Vol 14 (3) ◽  
pp. 659-681 ◽  
Author(s):  
Yehuda Kleiner ◽  
Balvant Rajani
Keyword(s):  
Water Distribution ◽  
Distribution Networks ◽  
Classification Model ◽  
Pipe Material ◽  
Homogeneous Poisson Process ◽  
Model Based ◽  
Water Mains ◽  
Natural Variations ◽  
Non Homogeneous Poisson Process ◽  
Subsequent Failure

The use of statistical methods to discern patterns of historical breakage rates and use them to predict water main breaks has been widely documented. Particularly challenging is the prediction of breaks in individual pipes, due to the natural variations that exist in all the factors that affect their deterioration and subsequent failure. This paper describes alternative models developed into operational tools that can assist network owners and planners to identify individual mains for renewal in their water distribution networks. Four models were developed and compared: a heuristic model, a naïve Bayesian classification model, a model based on logistic regression and finally a probabilistic model based on the non-homogeneous Poisson process (NHPP). These models rank individual water mains in terms of their anticipated breakage frequency, while considering both static (e.g. pipe material, diameter, vintage, surrounding soil, etc.) and dynamic (e.g. climate, operations, cathodic protection, etc.) effects influencing pipe deterioration rates.

scholarly journals Copula parameter estimation using Bayesian inference for pipe data analysis

2018 ◽  
Vol 45 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Farzana Atique ◽  
Nii Attoh-Okine
Keyword(s):  
Data Analysis ◽  
Soil Condition ◽  
Condition Assessment ◽  
Pipe Material ◽  
Data Set ◽  
Copula Modeling ◽  
Structural Deterioration ◽  
Copula Parameter ◽  
Water Mains ◽  
Non Gaussian

Water main systems are aging and becoming a growing concern for maintenance. The structural deterioration of water mains is affected by different factors, such as pipe age, pipe material, soil condition, and pipe size, among others. Various methods of modeling have been used to predict the failure of water mains. Since pipe networks are underground and obtaining data on pipe conditions is very costly, statistical modeling has been widely used for pipe condition assessment. An emerging statistical method known as copula modeling is used here for pipe data analysis. The copula method is very useful in cases where marginals belong to different families of distributions. It is also useful for generating a large number of data points when it is difficult to obtain a data set, as is the case for pipe condition assessment, and where data sets have random variables belonging to non-Gaussian family distributions. Different copula families are applied here to model the dependency between the pipe age and repair age of pipes. The paper uses a Bayesian framework to estimate the parameter values in the copula model. This approach offers an additional option for estimating copula parameters for pipe data.

Failure Analysis of CDM-ESD Damage in a GaAs RFIC

2000 ◽  
Author(s):  
Amy Poe ◽  
Steve Brockett ◽  
Tony Rubalcava
Keyword(s):  
Radio Frequency ◽  
Failure Analysis ◽  
Integrated Circuit ◽  
Production Test ◽  
Analysis Techniques ◽  
Device Model ◽  
Charged Device ◽  
Subsequent Failure

Abstract The intent of this work is to demonstrate the importance of charged device model (CDM) ESD testing and characterization by presenting a case study of a situation in which CDM testing proved invaluable in establishing the reliability of a GaAs radio frequency integrated circuit (RFIC). The problem originated when a sample of passing devices was retested to the final production test. Nine of the 200 sampled devices failed the retest, thus placing the reliability of all of the devices in question. The subsequent failure analysis indicated that the devices failed due to a short on one of two capacitors, bringing into question the reliability of the dielectric. Previous ESD characterization of the part had shown that a certain resistor was likely to fail at thresholds well below the level at which any capacitors were damaged. This paper will discuss the failure analysis techniques which were used and the testing performed to verify the failures were actually due to ESD, and not caused by weak capacitors.

Statistical approach for describing failures and lifetimes of water mains

1998 ◽  
Vol 38 (6) ◽  
pp. 209-217 ◽  
Author(s):  
Jianhua Lei ◽  
Sveinung Sægrov
Keyword(s):  
Data Base ◽  
Ductile Iron ◽  
Counting Process ◽  
Statistical Approach ◽  
Process Models ◽  
Average Lifetime ◽  
Maintenance Practice ◽  
Water Mains ◽  
Near Future

This paper demonstrates the statistical approach for describing failures and lifetimes of water mains. The statistical approach is based on pipe inventory data and the maintenance data registered in the data base. The approach consists of data pre-processing and statistical analysis. Two classes of statistical models are applied, namely counting process models and lifetime models. With lifetime models, one can estimate the probability which a pipe will fail within a time horizon. With counting process models one can see the deteriorating (or improving) trend in time of a group of “identical” pipes and their rates of occurrence of failure (ROCOF). The case study with the data base from Trondheim municipality (Norway) demonstrates the applicability of the statistical approach and leads to the following results: 1). In the past 20 years, Trondheim municipality has experienced approximately 250 to 300 failures per year. However, the number of failures per year will significantly increase in the near future unless better maintenance practice is implemented now. 2). Unprotected ductile iron pipes have a higher probability of failures than other materials. The average lifetime of unprotected ductile iron pipes is approximately 30 to 40 years shorter than the lifetime of a cast iron pipe. 3). Pipes installed 1963 and 1975 are most likely to fail in the future; 4) The age of a pipe does not play a significant role for the remaining lifetime of the pipe; 5). After 2 to 3 failures, a pipe enters a fast-failure stage (i.e., frequent multiple between failures).

scholarly journals The DWQ-EMR Embedded Tool to Enhance the Family Physician-Caregiver Connection: A Pilot Case Study

Geriatrics ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 29
Author(s):  
Kristina Marie Kokorelias ◽  
Einat Danieli ◽  
Sheila Dunn ◽  
Sid Feldman ◽  
David Patrick Ryan ◽  
...  
Keyword(s):  
Family Caregivers ◽  
Best Practice ◽  
Data Gathering ◽  
Family Physicians ◽  
Efficient Manner ◽  
Efficient Access ◽  
Increased Risk ◽  
Starting Point ◽  
To Receive

The number of family caregivers to individuals with dementia is increasing. Family physicians are often the first point of access to the health care system for individuals with dementia and their caregivers. Caregivers are at an increased risk of developing negative physical, cognitive and affective health problems themselves. Caregivers also describe having unmet needs to help them sustain care in the community. Family physicians are in a unique position to help support caregivers and individuals with dementia, but often struggle with keeping up with best practice dementia service knowledge. The Dementia Wellness Questionnaire was designed to serve as a starting point for discussions between caregivers and family physicians by empowering caregivers to communicate their needs and concerns and to enhance family physicians’ access to specific dementia support information. The DWQ aims to alert physicians of caregiver and patient needs. This pilot study aimed to explore the experiences of physicians and caregivers of people using the Questionnaire in two family medicine clinics in Ontario, Canada. Interviews with physicians and caregivers collected data on their experiences using the DWQ following a 10-month data gathering period. Data was analyzed using content analysis. Results indicated that family physicians may have an improved efficacy in managing dementia by having dementia care case specific guidelines integrated within electronic medical records. By having time-efficient access to tailored supports, family physicians can better address the needs of the caregiver–patient dyad and help support family caregivers in their caregiving role. Caregivers expressed that the Questionnaire helped them remember concerns to bring up with physicians, in order to receive help in a more efficient manner.

Managing Biomass Supply Chains

2020 ◽  
pp. 1-27
Author(s):  
Victoria Muerza ◽  
Luca Urciuoli ◽  
E. (Bert) Annevelink ◽  
J.C.M.A (Joost) Snels ◽  
Jan E. G. van Dam
Keyword(s):  
Supply Chains ◽  
Economies Of Scale ◽  
Agricultural Crops ◽  
Leadership Roles ◽  
Strategic Objectives ◽  
Biomass Logistics ◽  
Fodder Production ◽  
Management Leadership ◽  
Operational Activities

This chapter explores the feasibility and advantages of integrated biomass logistics centres (IBLCs). These are centres aiming to collect residues from farming activities and transform these into new intermediate bio-products. Operations in these IBLCs aim to achieve economies of scale through integration of resources and business lines, while creating technical and environmental advantages for firms and societies. The experience from one agro-industry case study in Spain (fodder production) highlights the importance of leadership roles to manage the newly created supply chains, through the identification of strategic objectives and the coordination of operational activities. Hence, the scope of this chapter is to review the concept of IBLCs under the lens of supply chain management leadership. Thereafter, it will discuss the potential to transfer the IBLC concept to emerging markets, with examples for African agricultural crops.

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