Search results for "scenario"
showing 10 items of 158 documents
A Dynamic Simulation Approach to Frame Drivers and Implications of Corruption Practices on Firm Performance
2014
Corruption is a multifaceted socio-economic phenomenon widely spread – although with different intensity – all around the world. Many studies on corruption have been conducted at a country-level, but relatively little effort has been placed in evaluating its implications, in terms of both financial and competitive performance, at a firm-level. Therefore, this paper aims at exploring the causal relationships underlying the effect of corruption on firm performance in order to show the different scenarios that may emerge from the combination between external (i.e., contextual conditions) and internal (i.e., organizational characteristics) forces that drive corruption. To this end, we adopt a D…
From local measures to regional impacts: Modelling changes in nutrient loads to the Baltic Sea
2021
Study Region: Our study region is the Baltic Sea Drainage Basin (BSDB), which covers an area of 1.8 Mio km2 distributed over 14 countries in northern Europe. Study Focus: We use a large-scale hydrological and nutrient transport model (E-HYPE) to model basin-wide impacts of measure scenarios on the Baltic Sea, where eutrophication is a critical issue for the marine ecosystem. We constructed measure scenarios based on stakeholder acceptance, established in workshops in different regions around the Baltic. These measures include local stream reach to catchment scale measures aiming to reduce nutrient transport into the stream network (buffer strips, stormwater ponds) and measures aiming to red…
Transit dose comparisons for60Co and192Ir HDR sources
2016
The goal of this study is to evaluate the ambient dose due to the transit of high dose rate (HDR) 60Co sources along a transfer tube as compared to 192Ir ones in a realistic clinical scenario. This goal is accomplished by evaluating air-kerma differences with Monte Carlo calculations using PENELOPE2011. Scatter from both the afterloader and the patient was not taken into account. Two sources, mHDR-v2 and Flexisource Co-60, (Elekta Brachytherapy, Veenendaal, the Netherlands) have been considered. These sources were simulated within a standard transfer tube located in an infinite air phantom. The movement of the source was included by displacing their positions along the connecting tube from …
Brief communication: Vehicle routing problem and UAV application in the post-earthquake scenario
2017
Abstract. In this paper we simulate a Unmanned Aerial Vehicle's (UAV) recognition after a possible case of diffuse damage after a seismic event in the town of Acireale (Sicily, Italy). Given a set of sites (84 relevant buildings) and the range of the UAV, we are able to find the number of vehicles to employ and the shortest survey path. The problem of finding the shortest survey path is an operational research problem called Vehicle Routing Problem (VRP) whose solution is known to be computationally time-consuming. We used the Simulated Annealing (SA) heuristic that is able to provide stable solutions in relatively short computing time. We also examined the distribution of the cost of the s…
Overcoming managers’ myopic decisions in a waste collection company
2019
Purpose The purpose of this paper is to show how the changing interrelationships between fleet management, human resources and outsourcer capacity areas are likely to counterbalance managerial policies, thereby generating a performance decay. The use of system dynamics modelling in a waste collection company offered an effective contribution to support decision makers to overcoming myopic decisions. Design/methodology/approach Literature review and a case study analysis (including interviews with company actors and data gathering) offered the basis to build a system dynamics model. The model built was then used to run simulations sessions to assess alternative investments decisions. Findin…
A life cycle scenario analysis of different pavement technologies for urban roads.
2019
In the past, lowest price was the award criterion, given that structural capacity and safety were assured. In the last years, environmental, energy, and long-term impacts have been introduced (climate change, resource depletion, energy consumption, generated solid waste, discharged water, and emissions). Unfortunately, the introduction of new pavement technologies and materials (i.e., waste plastics) affects maintenance and rehabilitation processes and call for accurate and timeliness studies and criteria. Consequently, this paper presents an energy and environmental assessment of an Italian urban road and considers different material-related scenarios that fully comply with emerging techno…
Risk Management Optimization for Sovereign Debt Restructuring
2015
Abstract Debt restructuring is one of the policy tools available for resolving sovereign debt crises and, while unorthodox, it is not uncommon. We propose a scenario analysis for debt sustainability and integrate it with scenario optimization for risk management in restructuring sovereign debt. The scenario dynamics of debt-to-GDP ratio are used to define a tail risk measure, termed conditional Debt-at-Risk. A multi-period stochastic programming model minimizes the expected cost of debt financing subject to risk limits. It provides an operational model to handle significant aspects of debt restructuring: it collects all debt issues in a common framework, and can include contingent claims, m…
Stochastic debt sustainability analysis for sovereigns and the scope for optimization modeling
2017
We express the opinion that sovereign debt sustainability analysis must be augmented by stochastic correlated risk factors and a risk measure to capture tail effects. Crisis situations can thus be adequately specified and analyzed with sufficient accuracy to warrant the relevance of policy decisions. In this context there is significant scope for optimization modeling for both strategic planning and operational management. We discuss diverse aspects of the problem of debt sustainability and highlight modeling approaches that can be brought to bear on the problem. Results with the fictitiuous, but nor unrealistic, Kingdom of Atlantis, which is sinking under excessive debt, illustrate the pro…