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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

A methodology to Develop an Integrated Engineering System to Estimate Quantities for Bridge Repairs at the Pre-Design Stage

Thaesler-Garibaldi, Maria P. 21 April 2005 (has links)
A Damage Assessment Model, Construction Process Model and Parametric Quantity Model were developed with the purpose of capturing the engineering knowledge involved in the estimating process of bridge repair construction projects. The Damage Assessment Model was used to create a sample database in which detailed inspection data was stored in a format compatible with the existing Pontis?tabase. Detailed inspection data, which provided quantitative values for the different damage types observed in bridges, could be retrieved from the sample database so that data could be used as either input parameters in the knowledge rules that triggered the selection of construction tasks in the Construction Process Model, or data could be used as variables in the equations used to estimate quantities in the Parametric Quantity Model. The Construction Process Model was used to incorporate the logic behind the construction process for different repair methods. The Construction Process Model was composed of seven repair matrices that defined specific repair methods for each Pontis?idge element. Construction tasks were grouped in construction modules that were modeled as flowcharts. Each construction module flowchart was composed of construction tasks arranged in sequential order and decision points that triggered the selection of construction tasks based on input parameters and knowledge rules. Input parameters were provided by the user, retrieved from the model or pre-defined in the model by expert knowledge. The construction modules developed involved construction tasks related to the repair of concrete bridge piles that were damaged due to reinforcement corrosion and related concrete deterioration. Data describing the construction tasks that were considered in the construction module flowcharts were modeled using the entity-relationship model and were stored in the sample database described previously. The Parametric Quantity Model combined data generated by the Damage Assessment Model and the Construction Process Model with additional expert knowledge and parameters into equations that were used to estimate quantities. The author investigated the use of neural networks as a tool to predict actual damage in bridge piles, conducted a preliminary survey to define labor productivity factors and collected data to define the duration of construction activities related to bridge repair.
12

Study of Possible Applications of Currently Available Building Information Modeling Tools for the Analysis of Initial Costs and Energy Costs for Performing Life Cycle Cost Analysis

Mukherji, Payal Tapandev 2010 December 1900 (has links)
The cost of design, construction and maintenance of facilities is on continual rise. The demand is to construct facilities which have been designed by apply life cycle costing principles. These principles have already given strong decision making power to the manufacturing industry. The need to satisfy the environmental sustainability requirements, improve operational effectiveness of buildings and apply value engineering principles has increased the dependency on life cycle costing analysis. The objective is to obtain economically viable solutions by analyzing the alternatives during the design of a building. Though the LCCA process is able to give the desired results, it does have some problems which have stood as hindrances to the more widespread use of the LCCA concept and method. The literature study has highlighted that the problem areas are the lack of frameworks or mechanisms for collecting and storing data and the complexity of LCCA exercise, which involves the analysis of a thousand of building elements and a number of construction-type options and maintenance activities for each building element at detailed design stages. Building Information Modeling has been able to repeatedly answer the questions raised by the AEC industry. The aim of this study is to identify the areas where BIM can be effectively applied to the LCCA process and become a part of the workflow. In this study, initially four LCCA case studies are read and evaluated from the point of view of understanding the method in which the life cycle costing principles have been applied. The purpose, the type alternatives examined, the process of analysis, the type of software used and the results are understood. An attempt has been carried out to understand the workflow of the LCCA process. There is a confidence that Building Information Modeling is capable of handling changes during the design, construction and maintenance phases of the project. Since applying changes to any kind of information of the building during LCC analysis forms the core, it has become necessary to use computer building models for examining these changes. The building modeling softwares are enumerated. The case studies have highlighted that the evaluation of the alternatives are primarily to achieve energy efficient solutions for the buildings. Applying these solutions involves high initial costs. The return on investment is the means by which these solutions become viable to the owners of the facilities. This is where the LCCA has been applied. Two of the important cost elements of the LCC analysis are initial costs and the operating costs of the building. The collaboration of these modeling tools with other estimating software where the initial costs of the building can be generated is studied. The functions of the quantity take-off tools and estimating tools along with the interoperability between these tools are analyzed. The operating costs are generated from the software that focuses on sustainability. And the currently used tools for performing the calculations of the life cycle costing analysis are also observed. The objective is to identify if the currently available BIM tools and software can help in obtaining LCCA results and are able to offset the hindrances of the process. Therefore, the software are studied from the point of view of ease of handling data and the type of data that can be generated. Possible BIM workflows are suggested depending on the functions of the software and the relationship between them. The study has aimed at taking a snapshot the current tools available which can aid the LCCA process. The research is of significance to the construction industry as it forms a precursor to the application of Building Information Modeling to the LCCA process as it shows that it has the capacity of overcoming the obstacles for life cycle costing. This opens a window to the possibility of applying BIM to LCCA and furthering this study.
13

Costing for the Future: Exploring Cost Estimation with Unmanned Autonomous Systems

Ryan, Thomas Robert Jr. January 2015 (has links)
This thesis explores three topics in the field of cost estimation for Unmanned Autonomous Systems. First, we propose a common definition of an Unmanned Autonomous System. We accomplish this through exhausting the literature in the areas cost estimation, autonomy in its current form, and how such advanced systems might be integrated into their environment. Second, we introduce a method to estimate the cost of Unmanned Autonomous Systems utilizing existing parametric cost estimation tools: SEER–HDR, COCOMO II, COSYSMO, and two cost estimating relationships–weight and performance. This discussion is guided by focusing on how current tools attempt to account for emergent systems. We also attempt to address challenges surrounding autonomy. To address these challenges from a cost perspective, this thesis recommends modifications to parameters within COCOMO II–via the use of object-oriented function points in lieu of current methods, and COSYSMO–via the introduction of two cost drivers namely, TVED and HRI-T. Third, we conduct analysis on four current Army Unmanned Autonomous Systems in an attempt to establish early trends within existing estimates. Finally, we explore areas of further research and discuss the implications of how pursing a more adequate cost model will lead to a better understanding of this ill-defined paradigm. *This material is based upon work supported by the Naval Postgraduate School Acquisition Research Program under Grant No. N00244-15-1-0008. The views expressed in written materials or publications, and/or made by speakers, moderators, and presenters, do not necessarily reflect the official policies of the Naval Postgraduate School nor does mention of trade names, commercial practices, or organizations imply endorsement by the U.S. Government.
14

An Expert System Integrated with a Bridge Information Management System (BrIMS), Cost Estimating, Deterioration Forecasting, and Linear Scheduling at the Conceptual Design Stage

Markiz, Nizar January 2018 (has links)
Major bridge stakeholders such as federal and provincial transportation agencies are in dire need for objective knowledge-based systems that assist decision-makers in the selection of bridge type. Besides that, estimating bridge construction costs at the conceptual design stage is an increasing necessity for accurate budgeting and effective allocation of funding. Whilst multiple bridge management systems have already been developed; they still possess major drawbacks pertaining to interoperability and integration with complex time and cost optimization-related problem solving. In another perspective, infrastructure restoration has been backlogged with multifaceted factors that have captured the attention of municipal and federal authorities. Several successful integrations of bridge information management systems (BrIMS) with decision support systems and computer-aided engineering design solutions have significantly leveraged downstream processes of bridge maintenance operations and inspired many researchers. The subjective nature of evaluating bridge conditions and deteriorations is the main factor that influences bridge maintenance, repair, and replacement decisions. In order to overcome this shortcoming, the objectives of this study are intended to demonstrate the viability of integrating a decision support system with a stochastic gamma deterioration model utilizing a probabilistic fuzzy logic strategic approach at the conceptual design stage. In summary, this study presents a systematic multi-objective knowledge-based approach for selecting bridge type, forecasting elemental deteriorations, linear scheduling, and estimating construction costs at the conceptual design stage. The proposed methodology comprises a framework to deploy a system that automatically generates conceptual cost estimates by integrating objective functions with bridge information modeling (BrIM) through an external data interchange protocol in synchrony with interoperability standards. Deployment of the developed system shall minimize the degree of subjectivity involved while decision makings pertaining to bridge projects and assists designers and cost engineers obtain results in an integrated quantitative, qualitative, and systematic manner. The successful deployment of the expert system signifies a technological achievement of novelty pertaining to the integration of bridge information modeling (BrIM) concept with probabilistic fuzzy logic strategic approaches at the conceptual design stage of bridges.
15

Comparing Time and Accuracy of Building Information Modeling to On-Screen Takeoff for a Quantity Takeoff of a Conceptual Estimate

Alder, Morgan A. 19 July 2006 (has links) (PDF)
Estimating is a critical aspect of every construction project. The most tedious component of an estimate is the quantity takeoff. Different tools are available to improve an estimator's productivity for a quantity takeoff. Faster quantity takeoffs enable estimator to bid more jobs. This study analyzed the time and accuracy of performing quantity takeoffs when using building information modeling (BIM) through a comparison study using Revit (BIM software) and On-Center's OST. In preparation for the study the researcher conducted a pilot study. Participants of the study were asked to perform a quantity takeoff using both Revit and OST. Their resulting data was then, analyzed comparing both the time and accuracy of each item taken off. The subjects' perspectives on the two different methods of performing takeoff are also included in the findings of this study. This study focused on a conceptual estimate takeoff for a small commercial building. The results of the study showed that, on average, those using BIM were able to perform the overall takeoff faster than those using OST while still maintaining equivalent accuracy. This study includes methods to improve productivity for quantity takeoff through an analysis of the takeoffs of counts, areas, and lengths. Findings of this study include methods, techniques, and cautions for performing a quantity takeoff using BIM.
16

Εφαρμογή των κοστολογικών συστημάτων στον τομέα των ξενοδοχειακών επιχειρήσεων

Ρούτση, Ελένη 28 September 2010 (has links)
Αναμφισβήτητα, τις τελευταίες δεκαετίες έχουν λάβει χώρα σημαντικές αλλαγές στο επιχειρησιακό περιβάλλον σε παγκόσμια κλίμακα, οι οποίες έχουν μεταβάλλει ριζικά τη δομή του. Παραδείγματα τέτοιων αλλαγών αποτελούν η εισαγωγή ευέλικτων συστημάτων παραγωγής, η εντατικοποίηση και η αυτοματοποίηση των παραγωγικών διαδικασιών, η αύξηση των γενικών εξόδων τόσο ως ποσό όσο και ως ποσοστό επί του συνολικού κόστους των προϊόντων, η μείωση του κόστους άμεσης εργασίας (κυρίως στη βιομηχανία ) ως ποσοστό του κόστους παραγωγής, η αύξηση της ποικιλίας προϊόντων που παράγονται σε μικρές ποσότητες και με διαφορετικές προδιαγραφές, η αύξηση του ρυθμού εισαγωγής νέων προϊόντων στην αγορά τα οποία έχουν μικρό κύκλο ζωής, η υιοθέτηση πελατοκεντρικού προσανατολισμού κ.α. Οι παραπάνω αλλαγές σε συνδυασμό με την αύξηση της έντασης του ανταγωνισμού και της συνεπακόλουθης μείωσης των περιθωρίων κέρδους, έχουν ανάγει σε πηγή ανταγωνιστικού πλεονεκτήματος την αποτελεσματική παρακολούθηση και, κυρίως, διοίκηση τους κόστους των ξενοδοχειακών επιχειρήσεων. Για τη λήψη ορθών επιχειρηματικών αποφάσεων απαιτείται ορθή πληροφόρηση, η οποία, σε μεγάλο βαθμό, στηρίζεται στα αριθμητικά μεγέθη που παράγει η κοστολογική οργάνωση των ξενοδοχειακών επιχειρήσεων. Εξάλλου, ο σωστός προγραμματισμός και η άσκηση της οικονομικής πολιτικής από το Κράτος απαιτεί επίσης σωστή και αντικειμενική πληροφόρηση, που στηρίζεται τα μέγιστα στα μεγέθη του κόστους. Η Κοστολόγηση είναι, δηλαδή, η διαδικασία που αριθμοποιεί τη ζωή των οικονομικών μονάδων, συγκεντρώνει, αναλύει, επεξεργάζεται, συσχετίζει τα αριθμητικά μεγέθη τα οποία συνοψίζει και παρουσιάζει καταλλήλως ώστε να είναι αξιοποιήσιμα από τους λήπτες των επιχειρηματικών αποφάσεων. Για να είναι όμως τα μεγέθη του κόστους αξιοποιήσιμα θα πρέπει, εκτός των άλλων, να τυγχάνουν μιας τέτοιας επεξεργασίας, κατάταξης και συσχετισμών ώστε να διασφαλίζεται η μέσω αυτών και δι’ αυτών κατάρτιση ορθών οικονομικών εκθέσεων και γενικά η άσκηση ελέγχου για την ορθότητα κάθε επιχειρηματικής απόφασης. Η σημαντικότητα του εργαλείου της κοστολόγησης για την παροχή αξιόπιστων πληροφοριών στη διοίκηση της ξενοδοχειακής επιχείρησης, για τη λήψη αποφάσεων αποτέλεσε έναυσμα για τη διενέργεια της παρούσας μελέτης η οποία αναφέρεται σε ένα από τα πλέον σύγχρονα πεδία έρευνας και ανάπτυξης της Λογιστικής Επιστήμης που συνδέεται με τη χρησιμοποίηση επιστημονικών μεθόδων, αρχών και κανόνων, στη Διοίκηση των επιχειρήσεων και ιδιαίτερα των ξενοδοχειακών. Όπως είναι γνωστό, η διοίκηση των επιχειρήσεων, πραγματοποιείται μέσω των λαμβανόμενων καθημερινά επιχειρηματικών αποφάσεων από τους υπεύθυνους φορείς εξουσίας – αρμοδιότητας και ευθύνης – που βρίσκονται σε όλα τα επίπεδα της Διοικητικής πυραμίδας. Αναλυτικότερα, οι επιμέρους στόχοι της παρούσας μελέτης είναι οι ακόλουθοι: Μέσα από την ανάλυση και την εμπειρική έρευνα των ξενοδοχείων να προκύψει μια πολιτική λογιστικής και κοστολογικής οργάνωσης αυτών, επισήμανση της σημασίας και του μεγέθους της τουριστικής ανάπτυξης της Ελλάδας, αναφορά στον εγχώριο και διεθνή ανταγωνισμό, παρουσίαση της κοστολογικής οργάνωσης των ξενοδοχείων και ανάλυση των κοστολογικών συστημάτων που χρησιμοποιούνται από αυτά, λαμβάνοντας υπόψη τις ιδιαιτερότητες του κλάδου των ξενοδοχειακών επιχειρήσεων που έχουν αντίκτυπο στην κοστολόγηση (τιμολόγηση, εποχικότητα, κόστος αδράνειας- υπολειτουργίας, value added, non value added δαπάνες, κ.λπ.). Η παρούσα διπλωματική μελέτη αποτελείται από οκτώ (8) κεφάλαια στα οποία πραγματεύονται τα ακόλουθα : Στο Κεφάλαιο 1 αναλύεται η δομή του ξενοδοχειακού συστήματος, στο Κεφάλαιο 2 αναλύεται η δομή του Τουριστικού συστήματος, στο Κεφάλαιο 3 αξιολογείται και παρουσιάζεται η οργάνωση του κόστους ως μεταβλητής που στηρίζει απαραιτήτως κάθε επιχειρηματική απόφαση, στο Κεφάλαιο 4 παρουσιάζεται η κοστολογική οργάνωση των ξενοδοχειακών επιχειρήσεων, στο Κεφάλαιο 5 αναλύεται ένα από τα σημαντικότερα είδη Κοστολόγησης, η Κοστολόγηση ανά δραστηριότητα, στο Κεφάλαιο 6 παρουσιάζονται στατιστικά στοιχεία για την χρηματοοικονομική ανάλυση του κλάδου των ξενοδοχειακών μονάδων, στο Κεφάλαιο 7 παρουσιάζεται η κοστολογική ανάλυση του κλάδου και στο Κεφάλαιο 8 παρουσιάζονται τα βασικά συμπεράσματα της μελέτης καθώς και προτάσεις βελτίωσης της εφαρμογής της κοστολόγησης στην εποχή μας. / Undeniably, the last decades have taken place important changes in the operational environment in world scale, that have alter radically his structure. Examples of such changes constitute the import of flexible systems of production, the intensifying and the automation of productive processes, the increase of general expenses so much as sum what as percentage on the total cost of products, the reduction of cost of direct work (mainly in the industry) as percentage of cost of production, the increase of variety of products that is produced in small quantities and with different specifications, the increase of rhythm of import of new products in the market which have small circle of life, the adoption of orientation to the customers, etc. The above changes in combination with the increase of intensity of competition and subsequent reduction of margins of profit, have reduced in source of competitive advantage the effective follow-up and, mainly, their administration of cost of hotel enterprises. For the decision-making equitable enterprising is required equitable information, which, to a great degree, is supported in the numerical sizes that produces the cost estimating organization of hotel enterprises. Moreover, the correct planning and the exercise of economic policy from the State require also correct and objective information that supports biggest in sizes of cost. The cost accounting is, that is to say, the process that puts in a line the life of economic units, assembles, analyzes, processes, connects the numerical sizes which it summarizes and presents suitably so that they are exploitable from the recipients of enterprising decisions. In order to be the sizes of cost exploitable it will be supposed, except the other, that they enjoy a such treatment, classification and correlations so that is ensured via these and of these training of equitable economic reports and in general the exercise of control on the correctness of each enterprising decision. The importance of tool of cost accounting for the benefit of reliable information in the administration of hotel enterprise, for the decision-making constituted spark for the realization of present study which is reported in one of the most modern fields of research and growth of Accountant Science that is connected with the utilization of scientific methods, values and rules, in the Administration of enterprises and particularly of hotels. As it is known, the administration of enterprises, it is realized via the received daily enterprising decisions by the responsible institutions of power- competence and responsibility - that they are found in all levels of Administrative pyramid. More analytically, the individual objectives of present study are the followings: Through the analysis and the empiric research of hotels result a policy accountant and cost estimating organization of these, pointing out of importance and size of tourist growth of Greece, report in the domestic and international competition, presentation of cost estimating organization of hotels and analysis of cost estimating systems that is used by them, taking into consideration his particularities of branch of hotel enterprises that have impact in the cost accounting (pricing, cost of inactivity, value added, non value added expenses, etc.). The present diplomatic study is constituted from eight (8) capitals in which deal with following: In Capital 1 it is analyzed the structure of hotel system, in Capital 2 it is analyzed the structure of Tourist system, in Capital 3 it is evaluated and presents itself the organization of cost as variable that supports essentially each enterprising decision, in Capital 4 it is presented the cost estimating organization of hotel enterprises, in Capital 5 it is analyzed one of the most important types of Cost accounting, the Cost accounting per activity, in Capital 6 they are presented statistical elements for the financing analysis of branch of hotel units, in Capital 7 it is presented the cost estimating analysis of branch and in Capital 8 they are presented the basic conclusions of study as well as proposals of improvement of application of cost accounting in our period of time.
17

Confidence Intervals on Cost Estimates When Using a Feature-based Approach

Iacianci, Bryon C. January 2012 (has links)
No description available.
18

A Comparative Study Of Regression Analysis, Neural Networks And Case

Karanci, Huseyin 01 September 2010 (has links) (PDF)
Construction cost estimating is essential for all of the stakeholders of a construction project from the beginning stage to the end. At early stages of a construction project, the design information and scope definition are very limited, hence / during conceptual (early) cost estimation, achieving high accuracy is very difficult. The level of uncertainty included in the cost estimations should be emphasized for making correct decisions throughout the dynamic stages of construction project management process, especially during early stages. By using range estimating, the level of uncertainties can be identified in cost estimations. This study represents integrations of parametric and probabilistic cost estimation techniques in a comparative base. Combinations of regression analysis, neural networks, case &ndash / based reasoning and bootstrap method are proposed for the conceptual (early) range cost estimations of mass housing projects. Practical methods for early range cost estimation of mass housing projects are provided for construction project management professionals. The methods are applied using bid offers of a Turkish contractor given for 41 mass housing projects. The owner of all projects is Housing Development Administration of Turkey (TOKI). The mass housing projects of TOKI are generally a mix of apartment blocks, social, health and educational facilities, and some projects may also have mosques. Results of the three different approaches are compared for predictive accuracy and predictive variability, and suggestions for early range cost estimation of construction projects are made.
19

Ceny dopravních staveb se zaměřením na pozemní komunikace / Prices of transport structures with a focus on road infrastructure

Fekete, László January 2012 (has links)
The aim of this work is to introduce the pricing for traffic constructions, more precisely for the road infrastructure in phase of preparation and realisation. There is a specific example of the cost estimating of a realized construction presented here. Then there is an analysis of an example focusing on the compliance with the financial limit of the planned construction. In the theoretical part of this thesis basic information about the traffic in the Czech Republic, a brief overview of the process of construction of roads, and price creation of the road structures with increased attention to cost estimating and possibilities of financing of roads are mentioned. In the last part of the work the evaluation of the work and samples of interesting facts about the current financing of transport constructions are presented.
20

Methodology for Cost Estimation of Systems at a Preliminary Stage of Design

Miller, Adam J. 11 September 2012 (has links)
No description available.

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