165 research outputs found

    Methodology for urban rail and construction technology research and development planning

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    A series of transit system visits, organized by the American Public Transit Association (APTA), was conducted in which the system operators identified the most pressing development needs. These varied by property and were reformulated into a series of potential projects. To assist in the evaluation, a data base useful for estimating the present capital and operating costs of various transit system elements was generated from published data. An evaluation model was developed which considered the rate of deployment of the research and development project, potential benefits, development time and cost. An outline of an evaluation methodology that considered benefits other than capital and operating cost savings was also presented. During the course of the study, five candidate projects were selected for detailed investigation; (1) air comfort systems; (2) solid state auxiliary power conditioners; (3) door systems; (4) escalators; and (5) fare collection systems. Application of the evaluation model to these five examples showed the usefulness of modeling deployment rates and indicated a need to increase the scope of the model to quantitatively consider reliability impacts

    Protecting built property against fire disasters: Multi ‐attribute decision making with respect to fire risk

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    The protection of buildings against fire disasters may require a comparison of alternative fire safety designs. The fire safety solutions can be compared by means of a general methodology known as multi‐attribute selection or multi‐criteria decision making. The alternative fire designs can be described by a number of attributes which characterise each of the alternatives. Fire risk expressed in the general form used for the quantitative risk assessment is applied to compose the set of attributes of a multi‐attribute selection problem. It is shown how to accomplish the multi‐attribute selection in the presence of epistemic uncertainties in the elements of fire risk estimate. Epistemic probability distributions assigned to elements of fire risk are specified and propagated though models of the multi‐attribute selection by means of Monte Carlo simulation. An example presented in the paper considers the choice among alternative systems of automatic fire sprinklers. Santruka Norint užtikrinti pastatu gaisrine sauga, gali prireikti lyginti alternatyvius projektinius saugos sprendimus. Tai atlikti galima pasitelkiant daugiakriterinio vertinimo metodologija. Alternatyvieji sprendimai gali būti aprašyti keletu charakteristiku (atributu) ir lyginami vienas su kitu. Straipsnyje atributu sarašas sudaromas naudojant gaisro rizikos išraiška, sudaroma kiekybinio rizikos vertinimo principais. Parodyta, kaip atlikti daugiakriterini vertinima, kai rizikos išraiškos elementai yra neapibrežti epistemine prasme. Episteminio neapibrežtumo skirstiniai priskiriami uždavinio atributams ir propaguojami matematiniais daugiakriterinio vertinimo modeliais pasitelkiant Monte Karlo modeliavima. Pateikiamas pavyzdys, nagrinejantis automatiniu sprinkleriu sistemos parinkima iš keliu alternatyviu variantu. First Published Online: 10 Feb 201

    Solving Civil Engineering Problems by Means of Fuzzy and Stochastic MCDM Methods: Current State and Future Research

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    The present review examines decision-making methods developed for dealing with uncertainties and applied to solve problems of civil engineering. Several methodological difficulties emerging from uncertainty quantification in decision-making are identified. The review is focused on formal methods of multiple criteria decision-making (MCDM). Handling of uncertainty by means of fuzzy logic and probabilistic modelling is analysed in light of MCDM. A sensitivity analysis of MCDM problems with uncertainties is discussed. An application of stochastic MCDM methods to a design of safety critical objects of civil engineering is considered. Prospects of using MCDM under uncertainty in developing areas of civil engineering are discussed in brief. These areas are design of sustainable and energy efficient buildings, building information modelling, and assurance of security and safety of built property. It is stated that before long the decision-making in civil engineering may face several methodological problems: the need to combine fuzzy and probabilistic representations of uncertainties in one decision-making matrix, the necessity to extend a global sensitivity analysis to all input elements of a MCDM problem with uncertainties, and an application of MCDM methods in the areas of civil engineering where decision-making under uncertainty is presently not common.The present review examines decision-making methods developed for dealing with uncertainties and applied to solve problems of civil engineering. Several methodological difficulties emerging from uncertainty quantification in decision-making are identified. The review is focused on formal methods of multiple criteria decision-making (MCDM). Handling of uncertainty by means of fuzzy logic and probabilistic modelling is analysed in light of MCDM. A sensitivity analysis of MCDM problems with uncertainties is discussed. An application of stochastic MCDM methods to a design of safety critical objects of civil engineering is considered. Prospects of using MCDM under uncertainty in developing areas of civil engineering are discussed in brief. These areas are design of sustainable and energy efficient buildings, building information modelling, and assurance of security and safety of built property. It is stated that before long the decision-making in civil engineering may face several methodological problems: the need to combine fuzzy and probabilistic representations of uncertainties in one decision-making matrix, the necessity to extend a global sensitivity analysis to all input elements of a MCDM problem with uncertainties, and an application of MCDM methods in the areas of civil engineering where decision-making under uncertainty is presently not common

    70th anniversary of the birth of Academician Edmundas Kazimieras Zavadskas

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    "70th anniversary of the birth of Academician Edmundas Kazimieras Zavadskas review."Technological and Economic Development of Economy, 20(2), pp. 182-19

    Methodology of hazards identification in construction work course

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    The building industry is characterised by high variety and variability of working processes and work environment conditions, which is conductive to accidents at work. It is pointed out that the process of analyzing hazards in construction work should correspond to the successive changes in the state of the civil structure being erected and to the associated changes in the state of the production system. The starting‐point for identifying hazards and determining the place and time of their occurrence should be a correctly drawn up graphic schedule of construction work. Santrauka Statybos pramonei būdinga didele darbo procesu ir darbo aplinkos salygu ivairove bei kintamumas, o tai daro poveiki nelaimingiems atsitikimams darbe. Pažymetina, kad statybos darbu pavoju analizavimo procesas turi būti suderintas su statomo visuomeninio pastato būkles pokyčiais ir su ja susijusiais gamybos sistemos būkles pasikeitimais. Rizikos veiksniu atpažinimo pradžioje bei nustatant ju atsiradimo vieta ir laika turetu būti tinkamai sudarytas statybos darbu kalendorinis planas. Reikšminiai žodžiai: profesine rizika, visuomenines paskirties statinys, gamybos proceso struktūra, avaringumo veiksniai, avaringumo rodikliai, statybos darbu kalendorinis plana

    Design with uncertainty: the role of future options for infrastructure integration

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    Decision making for effective infrastructure integration is challenging because the performance of long-lasting facilities is often difficult to foresee or well beyond the designer's control. We propose a new approach for integrating the construction/retrofitting of two or more types of facilities. Infrastructure integration has many perceived benefits, but practitioners also express serious doubts, particularly when it comes to civil engineering works. To substantiate this approach, we test all of the major options for integrating a ground source heat pump system with the construction/retrofitting of an archetypal office building. We use actual data from the United Kingdom, which represent a middle-of-the-road setting among major developed countries. The model highlights the sensitivity of the range of cost-effective solutions to the embedding of future options. The findings point to a clear need for appropriate standards for managing infrastructure integration. We expect this kind of model to find increasing applications among infrastructure complexes, particularly as cities become denser and more multifunctional.All authors wish to acknowledge the funding support of the EPSRC Centre for Smart Infrastructure and Construction at Cambridge University (EPSRC reference EP/K000314/1). Ying Jin would also like to acknowledge the funding support received from the Tsinghua–Cambridge–MIT Low-carbon University Alliance and the China Ministry of Education Key Lab of Eco-Planning & Green Building at Tsinghua University

    Technology development in construction: a continuum from distant past into the future

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    This paper deals with the historical and current trends in the development of civil engineering and construction technologies. The authors demonstrate the continuity of creative thought and effort among early master builders and technology developers throughout the history of civilizations that created the most iconic structures remaining in the world heritage of the built environment to the contemporary times. Recent concepts and ongoing efforts in the development of advanced construction technologies based on automation and information sciences, materials science and systems engineering are highlighted in the context of historical ideas and achievements of past architects and construction engineers of the past century

    Design of people evacuation from rooms and buildings

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    There is a fire hazard in many civil buildings or engineering structures. Analysis of people evacuation time from the room or building is an important part of the designing process. Nevertheless, analysis of human behaviour in fire conditions is very complicated. Various factors should be evaluated, physical and even psychical, influencing safe evacuation of people from buildings. The analytical and calculating methods created are intended for analysis of people evacuation in fire conditions. Unfortunately, use of complicated calculations for determination of people evacuation requires too many resources; therefore, their application is limited. The calculation method for people evacuation presented in this paper is based on dependencies of the physical characteristics of people stream (density, intensity, movement speed) on people movement manner. The time required to evacuate people from people gathering room and building is determined in the numerical illustration of the method application. The article presents the comparison of simple calculation method and modeling with FDS+Evac software results of time for safe evacuation of people from rooms and buildings. Santrauka Daugelyje civiliniu pastatu ar inžineriniu statiniu kyla gaisro rizikos pavojus. Žmoniu evakuacijos laiko iš patalpos ar statinio analize yra svarbi projektavimo dalis. Tačiau žmoniu elgsenos gaisro salygomis analize yra labai sudetinga. Ivairūs fizikiniai ir netgi psichologiniai veiksniai, darantys itaka saugiai žmoniu evakuacijai iš statiniu, turi būti ivertinti. Išrasti analitiniai ir skaičiuojamieji metodai, skirti žmoniu evakuacijai gaisro salygomis analizuoti. Deja, sudetingu skaičiavimu metodu taikymas žmoniu evakuacijai nustatyti reikalauja pernelyg daug ištekliu, todel ju taikymas yra ribotas. Šiame straipsnyje pateikiamas žmoniu evakuacijos skaičiavimo metodas, paremtas fizikinemis žmoniu srauto charakteristikomis (tankiu, intensyvumu, judejimo greičiu), priklausomai nuo žmoniu judejimo būdo. Palyginti aprašyto ir sudetingojo žmoniu evakuacijos skaičiavimo metodu, naudojant FDS+Evac programine iranga, rezultatai. Published Published Online: 24 Jun 2011 Reikšminiai žodžiai: žmoniu evakuacija, sauga, evakuacijos laikas, FDS+Eva

    Risk and vulnerability analysis in society’s proactive emergency management: Developing methods and improving practices

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    Risk and vulnerability analyses can play important roles in the society’s proactive emergency management. This thesis addresses two ways of improving the analysis of risk and vulnerability analysis in this context. First, by developing methods for risk and vulnerability analysis of technical infrastructure networks and emergency response systems. Secondly, by aiming to improve practises related to RVA through an evaluation of Swedish municipal RVAs and an empirical study of how various disaster characteristics affect people judgments of disaster seriousness. The research has to a large extent been carried out by using a design research approach developed in the thesis

    A product lifecycle framework for environmental management and policy analysis : case study of automobile recycling

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1995.Includes bibliographical references (leaves 122-123).by Andrew Chinshun Chen.Ph.D
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