10,068 research outputs found
Electricity load profile classification using Fuzzy C-Means method
This paper presents the Fuzzy C-Means (FCM) clustering method. The FCM technique assigns a degree of membership for each data set to several clusters, thus offering the opportunity to deal with load profiles that could belong to more than one group at the same time. The FCM algorithm is based on minimising a c-means objective function to determine an optimal classification. The simulation of FCM was carried out using actual sample data from Indonesia and the results are presented. Some validity index measurements was carried out to estimate the compactness of the resulting clusters or to find the optimal number of clusters for a data set
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A Difference-in-Differences Approach to Assess the Effect of a Heat Action Plan on Heat-Related Mortality, and Differences in Effectiveness According to Sex, Age, and Socioeconomic Status (Montreal, Quebec).
BackgroundThe impact of heat waves on mortality and health inequalities is well documented. Very few studies have assessed the effectiveness of heat action plans (HAPs) on health, and none has used quasi-experimental methods to estimate causal effects of such programs.ObjectivesWe developed a quasi-experimental method to estimate the causal effects associated with HAPs that allows the identification of heterogeneity across subpopulations, and to apply this method specifically to the case of the Montreal (Quebec, Canada) HAP.MethodsA difference-in-differences approach was undertaken using Montreal death registry data for the summers of 2000-2007 to assess the effectiveness of the Montreal HAP, implemented in 2004, on mortality. To study equity in the effect of HAP implementation, we assessed whether the program effects were heterogeneous across sex (male vs. female), age (≥ 65 years vs. < 65 years), and neighborhood education levels (first vs. third tertile). We conducted sensitivity analyses to assess the validity of the estimated causal effect of the HAP program.ResultsWe found evidence that the HAP contributed to reducing mortality on hot days, and that the mortality reduction attributable to the program was greater for elderly people and people living in low-education neighborhoods.ConclusionThese findings show promise for programs aimed at reducing the impact of extreme temperatures and health inequities. We propose a new quasi-experimental approach that can be easily applied to evaluate the impact of any program or intervention triggered when daily thresholds are reached. Citation: Benmarhnia T, Bailey Z, Kaiser D, Auger N, King N, Kaufman J. 2016. A difference-in-differences approach to assess the effect of a heat action plan on heat-related mortality, and differences in effectiveness according to sex, age, and socioeconomic status (Montreal, Quebec). Environ Health Perspect 124:1694-1699; http://dx.doi.org/10.1289/EHP203
Using a fuzzy inference system to control a pumped storage hydro plant
The paper discusses the development of a fuzzy inference system (FIS) based governor control for a pumped storage hydroelectric plant. The First Hydro Company's plant at Dinorwig in North Wales is the largest of its kind in Europe and is mainly used for frequency control of the UK electrical grid. In previous investigations, a detailed model of the plant was developed using MATLAB(R)/SIMULINK(R) and this is now being used to compare FIS governor operation with the proportional-integral-derivative (PID) controller currently used. The paper describes the development of an FIS governor, and shows that its response to a step increase in load is superior to the PID under certain conditions of load. The paper proceeds to discuss the implications of these results in view of the possible practical application of an FIS governor at the Dinorwig plant
Benefits Cost Anaylsis: Options for Sea Level Rise Adaptation on West Cliff Drive
This report presents the results of a benefit cost analysis of various options for adapting West Cliff Drive (in the City of Santa Cruz, California) to sea level rise as identified through extensive technical analysis and community input. This report has built on previous work completed as part of the West Cliff Drive Adaptation and Management Plan project. The previous work products provided much of the information needed for this benefit cost analysis included an existing conditions inventory, future exposure and vulnerability assessment, and an adaptation alternatives analysis. Since most of the West Cliff Drive corridor is publicly owned by the City of Santa Cruz and California State Parks, results of the future exposure and vulnerability assessment showed that little private property and only small portions of public infrastructure is at risk in the future. Thus, the benefit cost analysis focuses primarily on changes to the recreational uses of the West Cliff Drive corridor.
One challenge to adaptation planning is the uncertainty associated with the rate and elevation of sea level rise at future points of time, critical to the question of what to do and when. To deal with this uncertainty, the benefit cost analysis uses a technique called Monte Carlo analysis, a technique to test many different possible scenarios of sea level rise; in this analysis, 100,000 different scenarios were examined in every run of the analysis. The underlying sea level rise data is the same as used by the State of California in its various sea level rise planning guidance documents. This approach to the benefit cost analysis allows an estimate not only of net benefits but also the probability of positive net benefits of each adaptation strategy.
The purpose of this benefit cost analysis is to compare the economic benefits and costs of the coastal adaptation options aimed at managing coastal erosion to a future in which no additional adaptation actions beyond those routinely taken by the City are taken. The benefit cost analysis is designed to support a choice between those different adaptation strategies which involve substantial new expenditures by the City the or “business as usual” strategy. The fundamental question is whether it is economically worthwhile for the City to invest substantial resources in adapting to sea level rise along West Cliff Drive compared with continuing as they have in the past? Economically worthwhile projects have benefits greater than costs, taking into account the differences in timing of spending and receipt of benefits. This concept is called the net present value.
Four scenarios are examined: Business as Usual – No actions are taken beyond routine maintenance and irregular emergency repairs Managed Retreat – Existing armoring structures are removed, and natural erosion and shoreline processes restored. Recreation Focused Strategy – A combination of sand management, reduction in coastal armoring footprints and sand retention structures along with structural adaptation in high hazard areas such as sea caves. Protection Focused Strategy – Projects that stabilize the shoreline such as revetments, seawalls, filling of sea caves, and construction of artificial bedrock
Structural use of bamboo. Part 2: Durability and preservation
Bamboo is a strong, fast growing and very sustainable material, having been used structurally for thousands of years in many parts of the world. In modern times, it has the potential to be an aesthetically pleasing and low cost alternative to more conventional materials, such as timber, as demonstrated by some visually impressive recent structures. This five-part technical series, aimed at both developed- and developing-world contexts, will bring together current knowledge and best practice on the structural use of bamboo, covering: • an introduction to bamboo (part 1) • durability and preservation (part 2) • design values (part 3) • element design equations (part 4) • connections (part 5) This second article presents the main causes of decay of bamboo and the different methods of protection and preservation available
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