Modeling and Solving Project Portfolio and Contractor Selection Problem Based on Project Scheduling under Uncertainty

AbstractIn this paper a new formulation of the project portfolio selection problem based on the project schedules in uncertain circumstances have been proposed. The project portfolio selection models usually disregard the project scheduling, whereas is an element of the project selection process. We investigate a project portfolio selection problem based on the schedule of the projects, so that the minimum expected profit would be met in the shortest possible time period. Also due to uncertain nature of durations of the activities, this duration considered as the semi-trapezoidal fuzzy numbers. Finally, a fuzzy linear programming model is developed for the problem, where the results indicated the validity of the presented model

Operational Risk Management (ORM) 1

Abstract: This article discusses the management process of operational risk in financial institutions. While risk management has always been an integral part of financial activity, the 1990s has seen risk management establish itself as a key function within banks and other financial institutions. With greater emphasis on ensuring that money is not lost through adverse market conditions, counterparty failure or inappropriate controls, systems or people, risk management has become a discipline in its own right within financial markets. In this paper, we first review the different steps of the risk management process with respect to operational risk in the banking industry: the definition of operational risk, quantitative and qualitative methods for measuring operational risk, and risk management methods with respect to operational risk. In this study, we focus on the particular difficulties that arise with operational risk and argue that these steps cannot be treated separately as opposed to the management process of market or credit risk

Direct use of solar radiation for heating and cooling of residential buildings in hot-arid climates

Vita.The decade of the 1970's will be remembered as the era of energy crises--a time for the re-evaluation of technology, industry, and the way of life in modern society. For the first time man's dependence on energy from finite resources of fossil fuels became a major consideration. Despite the economic and political impact of the energy crisis and the uncertainty of the future availability of energy, this crisis was an enlightening lesson in energy conservation. Exploration for new sources of energy, especially the energy from the sun, became the subject for research in many institutions of higher learning. The present study and many others of this nature are the by-products of the energy crisis of the 1970's. This study demonstrates that the direct use of solar radiation for heating and cooling of residential buildings in hot-arid regions is not only an effective and reliable alternative for conserving a significant amount of energy sources every year but also plays an important role in lowering the pollution level in the environment. Homes can be built to take advantage of the enormous amount of clean energy available from the sun. This study undertakes a review and evaluation of the current passive heating and cooling features used primarily in residential buildings. The suitability and efficiency of these features in hot-arid climates is one of the primary considerations. A model solar house is designed using the most suitable passive heating and cooling systems. Through computer simulation the annual energy requirements of the solar house are compared to that of a conventional house designed using current standard practice. The weather simulation model uses the weather data generated for four cities in Iran which are used as the location for these houses. The thermal analysis and evaluations of the solar and the conventional houses indicate that the solar houses uses 82% less heating energy than that of the conventional house. The computer program used in this study does not consider the thermal effect of the passive cooling features in it calculations. When the thermal contributions of the passive heating and cooling features are considered in the overall thermal behavior of the solar house, the annual energy requirements of the building are considerably less than that indicated in the computer results presented in graph forms. In effect, it can be assessed that a properly designed solar house in hot-arid regions requires practically no purchased energy during the summer or winter months

Combining Monte Carlo Simulation and Bayesian Networks Methods for Assessing Completion Time of Projects under Risk

In this study, Monte Carlo simulation and Bayesian network methods are combined to present a structure for assessing the aggregated impact of risks on the completion time of a construction project. Construction projects often encounter different risks which affect and prevent their desired completion at the predicted time and budget. The probability of construction project success is increased in the case of controlling influential risks. On the other hand, interactions among risks lead to the increase of aggregated impact of risks. This fact requires paying attention to assessment and management of project aggregated risk before and during the implementation phase. The developed structure of this article considers the interactions among risks to provide an indicator for estimating the effects of risks, so that the shortage of extant models including the lack of attention to estimate the aggregated impact caused by risks and the intensifying impacts can be evaluated. Moreover, the introduced structure is implemented in an industrial case study in order to validate the model, cover the functional aspect of the problem, and explain the procedure of structure implementation in detail

An Overview Of Iranian Ice Repositories, An Example Of Traditional Indigenous Architecture

Publisher's Versio

Combining Monte Carlo Simulation and Bayesian Networks Methods for Assessing Completion Time of Projects under Risk

In this study, Monte Carlo simulation and Bayesian network methods are combined to present a structure for assessing the aggregated impact of risks on the completion time of a construction project. Construction projects often encounter different risks which affect and prevent their desired completion at the predicted time and budget. The probability of construction project success is increased in the case of controlling influential risks. On the other hand, interactions among risks lead to the increase of aggregated impact of risks. This fact requires paying attention to assessment and management of project aggregated risk before and during the implementation phase. The developed structure of this article considers the interactions among risks to provide an indicator for estimating the effects of risks, so that the shortage of extant models including the lack of attention to estimate the aggregated impact caused by risks and the intensifying impacts can be evaluated. Moreover, the introduced structure is implemented in an industrial case study in order to validate the model, cover the functional aspect of the problem, and explain the procedure of structure implementation in detail.This article belongs to the Special Issue Occupational Safety and Risks in Constructio

Expert System for Bone Scan Interpretation Improves Progression Assessment in Bone Metastatic Prostate Cancer.

INTRODUCTION The bone scan index (BSI) was introduced as a quantitative tool for tumor involvement in bone of patients with metastatic prostate cancer (mPCa). The computer-aided diagnosis device for BSI analysis EXINIbone(BSI) seems to represent technical progress for the quantitative assessment of bone involvement. But it is not yet clear if the automated BSI (aBSI) could contribute to improved evaluation of progression in patients under antiandrogens or chemotherapy in contrast to the visual interpretation and/or conventional biomarkers such as the prostate-specific antigen (PSA). METHODS In 49 mPCa patients, bone scans were performed initially and during different therapy courses. Scans were evaluated visually and by the artificial-neural-network-based expert system EXINIbone(BSI). Progression of metastatic bone involvement was defined according to the Prostate Cancer Clinical Trials Working Group 2 (PCWG2) criteria in the visual interpretation. The computer-assisted interpretation was based on different cutoff values in relative changes of the aBSI. Additionally, assessments according to bone scanning were compared to changes in the PSA value as a potential surrogate for treatment response. RESULTS Using a sensitive cutoff value (5% or 10%) for the relative aBSI increase led to significantly increased progression determination compared to the visual interpretation of bone scans (49% and 43% vs. 27%, p < 0.001). In 63% of the cases PSA and BSI changes matched, whereas in 18% progression was only indicated by the aBSI. A relative cutoff of 5% for the aBSI decrease could reclassify 47 serial scan pairs which were visually interpreted as stable into 22 progressive and 25 remissive scans. CONCLUSION Distinct thresholds of the relative aBSI could help to better assess disease progression in mPCa patients. Manual corrections of the BSI values are not required in most cases. The aBSI could serve as a useful additional parameter for therapy monitoring in mPCa patients in the future