6,591 research outputs found

    Ensuring Urban Water Security in Water-Scarce Regions of the United States

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    On December 11-13, 2013, The Johnson Foundation at Wingspread, along with partner ReNUWit, convened experts from different parts of the country to discuss the implications of chronic and episodic water scarcity on our nation's water infrastructure -- with the goal of moving beyond the "case-by-case" conversation to one about how cities can transform their infrastructure and management strategies. The resulting report identifies key principles of water security and explores components of good strategy and innovative water supply options while building the case for transformation

    A risk mitigation framework for construction / asset management of real estate and infrastructure projects

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    The increasing demand on residential, office, retail, and services buildings as well as hotels and recreation has been encouraging investors from both private and public sectors to develop new communities and cities to meet the mixed demand in one location. These projects are huge in size, include several diversified functions, and are usually implemented over many years. The real estate projects’ master schedules are usually initiated at an early stage of development. The decision to start investing in infrastructure systems, that can ultimately serve fully occupied community or city, is usually taken during the early development stage. This applies to all services such as water, electricity, sewage, telecom, natural gas, roads, urban landscape and cooling and heating. Following the feasibility phase and its generated implementation schedule, the construction of the infrastructure system starts together with a number of real estate projects of different portfolios (retail, residential, commercial,…etc.). The development of the remaining real estate projects continues parallel to customer occupancy of the completed projects. The occurrence of unforeseen risk events, post completing the construction of infrastructure system, may force decision makers to react by relaxing the implementation of the remaining unconstructed projects within their developed communities. This occurs through postponing the unconstructed project and keeping the original feasibility-based sequence of projects unchanged. Decision makers may also change the sequence of implementing their projects where they may prioritize either certain portfolio or location zone above the other, depending on changes in the market demand conditions. The change may adversely impact the original planned profit in the original feasibility. The profit may be generated from either real estate portfolios and/or their serving Infrastructure system. The negative impact may occur due to possible delayed occupancy of the completed real estate projects which in turn reduces the services demand. This finally results in underutilization of the early implemented Infrastructure system. This research aims at developing a dynamic decision support prototype system to quantify impacts of unforeseen risks on the profitability of real estate projects as well as its infrastructure system in the cases of changing projects’ implementation schedules. It is also aimed to support decision makers with scheduled portfolio mix that maximizes their Expected Gross Profit (EGP) of real estate projects and their infrastructure system. The provided schedules can be either based on location zone or portfolio type to meet certain marketing conditions or even to respect certain relations between neighbor projects’ implementation constraints. In order to achieve the research objectives, a Risk Impact Mitigation (RIM) decision support system is developed. RIM consists mainly of four models, Real Estate Scheduling Optimization Model RESOM, Sustainable Landscape Optimization Model SLOM, District Cooling Optimization Model DCOM and Water Simulation Optimization Model WSOM. Integrated with the three Infrastructure specialized models SLOM, DCOM, WSOM, RESOM provides EGP values for individual Infrastructure systems. The three infrastructure models provide the demand profile that relate to a RESOM generated implementation schedule. RESOM then uses these profiles for calculating the profits using the projects’ capital expenditure and financial expenses. The three models included in this research (SLOM, DCOM and WSOM) relate to the urban landscape, district cooling and water systems respectively. RIM is applied on a large scale real estate development in Egypt. The development was subjected to difficult political and financial circumstances that were not forecasted while preparing original feasibility studies. RIM is validated using a questionnaire process. The questionnaire is distributed to 31 experts of different academic and professional background. RIM’s models provided expected results for different real life cases tested by experts as part of the validation process. The validation process indicated that RIM’s results are consistent, in compliance with expected results and is extremely useful and novel in supporting real estate decision makers in mitigating risk impacts on their profits. The validation process also indicated promising benefits and potential need for developed commercial version for future application within the industry

    Caution Ahead: Overdue Investments in New York's Aging Infrastructure

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    While Superstorm Sandy focused much-needed attention on key pieces of New York City's infrastructure, the city faces a number of other infrastructure vulnerabilities that have little to do with storm-preparedness -- from aging water mains and deteriorating roads to crumbling public schools. If left unchecked, they could wreak havoc on the city's economy and quality of life

    Gap Analysis Based Decision Support Methodology to Improve Level of Service of Water Services

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    One of water utility’s managerial challenges is to make a balance in between two distinctive managerial goals, cost-effective provision of water service and improving customer satisfaction of water service. As management priorities of the water utility perspective do not reconcile from the customer’s perspective, this gap challenges the sustainable provision of water service. In this study, the new methodology based on a gap analysis was proposed to improve the Overall Level of Service (O-LOS) of water service. Two new indexes (Gap Index [GI] and the Efficiency Index [EI]) were developed to improve the O-LOS and minimize the gap between the customers and the service providers. The methodology proposed in this study is effective in supporting the water utility decisions on budget allocation to make a balance in between the customers’ demand and the service providers’ needs

    Bi-objective modeling approach for repairing multiple feature infrastructure systems

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    A bi-objective decision aid model for planning long-term maintenance of infrastructure systems is presented, oriented to interventions on their constituent elements, with two upgrade levels possible for each element (partial/full repairs). The model aims at maximizing benefits and minimizing costs, and its novelty is taking into consideration, and combining, the system/element structure, volume discounts, and socioeconomic factors. The model is tested with field data from 229 sidewalks (systems) and compared to two simpler repair policies, of allowing only partial or full repairs. Results show that the efficiency gains are greater in the lower mid-range budget region. The proposed modeling approach is an innovative tool to optimize cost/benefits for the various repair options and analyze the respective trade-offs.info:eu-repo/semantics/publishedVersio

    Microgrids & District Energy: Pathways To Sustainable Urban Development

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    A microgrid is an energy system specifically designed to meet some of the energy needs of a group of buildings, a campus, or an entire community. It can include local facilities that generate electricity, heating, and/or cooling; store energy; distribute the energy generated; and manage energy consumption intelligently and in real time. Microgrids enable economies of scale that facilitate local production of energy in ways that can advance cost reduction, sustainability, economic development, and resilience goals. As they often involve multiple stakeholders, and may encompass numerous distinct property boundaries, municipal involvement is often a key factor for successful implementation. This report provides an introduction to microgrid concepts, identifies the benefits and most common road blocks to implementation, and discusses proactive steps municipalities can take to advance economically viable and environmentally superior microgrids. It also offers advocacy suggestions for municipal leaders and officials to pursue at the state and regional level. The contents are targeted to municipal government staff but anyone looking for introductory material on microgrids should find it useful

    National flood damage evaluation methods: A review of applied methods in England, the Netherlands, the Czech Republik and Germany

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    The focus of this guidance document is decision making under uncertainty in river basin management. Our purpose is to give hints for the analysis of decision situations in the HarmoniRiB case studies. The background of HarmoniRiB and thus of the case studies is the implementation of the EU-Water Framework Directive. The directive states the goal that all waters3 in the EU should reach a good status4 by 20155. In order to achieve this goal the member states need to set up river basin districts, each one having a management plan that includes a programme of measures which will achieve good status in the most costeffective manner. We conceptualize this management problem as a decision problem: Which measures should be selected for the programme of measures? The HarmoniRiB case studies are not able to cover all problems of the implementation of the EU-Water Framework Directive in all their complexity. They only investigate certain aspects of this problem. Therefore, we concentrate in this guidance document on a certain type of decision, the selection of management measures to reach a certain goal (this would usually be good status) for the case study river basins. Thereby we put a special focus on uncertainties. --

    PREDICTION OF REMAINING USEFUL LIFE FOR COMPONENTS IN SSC OF RSG-GAS BASED ON RELIABILITY ANALYSIS

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    In the maintenance system, efforts are needed to improve the effectiveness of the maintenance system and organization. For effective maintenance planning it is necessary to have a good understanding of the reliability and component availability of the system. For this reason, it is necessary to determine the remaining component life using Remaining Useful Life (RUL), so that maintenance tasks can be planned effectively. The purpose of this study is to determine the remaining life of the safety A component from SSC RSG-GAS based on reliability analysis. The method used in this paper is a statistical approach to estimating RUL. The Weibull hazard model is determined for modeling the hazard function so that it can be integrated in the reliability analysis. The model is verified using data from the safety A component from the SSC RSG-GAS. The results obtained from the analysis are useful for estimating the remaining useful lives of these components which can then be used to plan for effective maintenance and help control unplanned outages. The results obtained can be used for maintenance development and preventive repair planning
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