Resource Allocation in Integrated Preoperational and Operational Management of Natural Hazards

The management of natural hazards occurring over a territory entails two main phases: a preoperational —or pre-event—phase, whose objective is to relocate resources closer to sites characterized by the highest hazard, and an operational —during the event—phase, whose objective is to manage in real time the available resources by allocating them to sites where their intervention is needed. Obviously, the two phases are closely related, and demand a unified and integrated treatment. This work presents a unifying framework that integrates various decisional problems arising in the management of different kinds of natural hazards. The proposed approach, which is based on a mathematical programming formulation, can support the decisionmakers in the optimal resource allocation before (preoperational phase) and during (operational phase) an emergency due to natural hazard events. Different alternatives of modeling the resources and the territory are proposed and discussed according to their appropriateness in the preoperational and operational phases. The proposed approach can be applied to the management of any natural hazard and, from an integration perspective, may be particularly useful for risk management in civil protection operations. An application related to the management of wildfire hazard is presented.     

Information theoretic results for circular distributions

The broad class of generalized von Mises (GvM) circular distributions has certain optimal properties with respect to information theoretic quantities. It is shown that, under constraints on the trigonometric moments, and using the Kullback–Leibler information as the measure, the closest circular distribution to any other is of the GvM form. The lower bounds for the Kullback–Leibler information in this situation are also provided. The same problem is also considered using a modified version of the Kullback–Leibler information. Finally, series expansions are given for the entropy and the normalizing constants of the GvM distribution.     

Just-in-time in ATO vehicle manufacturing: The Minivan-Piaggio V.E. case study

The system adopted by Piaggio V.E. to run the production of 'Minivan' aims at conciliating the manufacturing philosophy 'just-in-time' JIT with the creation of a wide range of end-product codes. Some general assumptions for a JIT production, with small lot sizes, are described together with their implementation in the operationorganizing system adopted by Piaggio V.E. for the 'Minivan' assembly line. The strategy pursued by Piaggio V.E. for the Minivan focuses on the quality of the product and the level of service in the form of fast order cycle and a high number of options offered on catalogue. According to the logic of an ATO production system, the customer orders a customized product and the manufacturer does not keep any finished inventory, but aims at effective management of the information flows.     

Service and Life Quality: The Case of Palermo

The research aims at analysing the ``quality' of some services offered to the citizens by the Commune of Palermo. The data available were gathered thanks to a sampling survey carried out in October 1997. The sample is made up of 1008 residents in the city of Palermo and is proportionally stratified according to the quarter of residence. Information was gathered by means of a telephone questionnaire. The answering rate was rather high and a great interest in the subjects dealt was taken.The research wants to individuate the degree of efficiency of the Commune of Palermo, also at administrative level, with some questions concerning the municipal council, taking the expectations of the citizens of the city into account through an analytic survey of the indicators measuring the judgement of the citizen towards the main services. This result will be the starting point of an exhaustive analysis aiming at the individuation of the ``quality of life' in Palermo, which is tightly connected with the services offered.     

Assessing the use of sample selection models in the estimation of fertility postponement effects

Several studies have shown that at the individual level there exists a negative relationship between age at first birth and completed fertility. Using twin data in order to control for unobserved heterogeneity as possible source of bias, Kohler et al. (2001) showed the significant presence of such "postponement effect" at the micro level. In this paper, we apply sample selection models, where selection is based on having or not having had a first birth at all, to estimate the impact of postponing first births on subsequent fertility for four European nations, three of which have now lowest-low fertility levels. We use data from a set of comparative surveys (Fertility and Family Surveys), and we apply sample selection models on the logarithm of total fertility and on the progression to the second birth. Our results show that postponement effects are only very slightly affected by sample selection biases, so that sample selection models do not improve significantly the results of standard regression techniques on selected samples. Our results confirm that the postponement effect is higher in countries with lowest-low fertility levels.     

Handling co-dependence issues in resampling-based variable selection procedures: a simulation study

If a number of candidate variables are available, variable selection is a key task aiming to identify those candidates which influence the outcome of interest. Methods as backward elimination, forward selection, etc. are often implemented, despite their drawbacks. One of these drawbacks is the instability of their results with respect to small perturbations in the data. To handle this issue, resampling-based procedures have been introduced; using a resampling technique, e.g. bootstrap, these procedures generate several pseudo-samples that are used to compute the inclusion frequency of each variable, i.e. the proportion of pseudo-samples in which the variable is selected. Based on the inclusion frequencies, it is possible to discriminate between relevant and irrelevant variables. These procedures may fail in case of correlated variables. To deal with this issue, two procedures based on 2×2 tables of inclusion frequencies have been developed in the literature. In this paper we analyse the behaviours of these two procedures and the role of their tuning parameters in an extensive simulation study.     

Analysing Space-Time Accessibility Towards the Implementation of the Light Rail System: The Case Study of Brescia

This paper proposes a methodology for investigation of the space–time relations of accessibility to public services and collective mobility. The paper assesses the space–time efficiency of local public transport facilities and makes an accessibility analysis as a baseline for evaluating future changes. It explains the potential for improvement and the effects on planning paradigms. Public transport accessibility greatly changes during day and night time so they should be assessed through multi-scaled and diachronic maps as a contribution to the timetable plan and overall planning strategies. The case study of Brescia, Italy is used to test the methodology. The new light rail system of Brescia entered into operation in 2013 and could change the entire form of urban mobility.     

Shedding light on the aim of stock options: a literature review

Stock options (hereafter SOs) have been extensively investigated by the literature. The debate has been mainly grounded in the agency theory that has interpreted these tools as mechanisms to align the conflicting interests of managers and owners towards the shareholder value maximization. However, the latest empirical evidence suggests that SOs are often used by opportunistic managers to extract rents to the detriment of shareholders. In addition, literature identifies the perceived cost as a further theoretical lens to interpret the use of SOs. Despite the growing interest around the topic, the research is still fragmented and fails to present a comprehensive picture on the factors that affect the aim of SOs. Our literature review attempts to fill this gap by providing a systematization of the studies on the topic. The paper concludes by presenting the theoretical and practical implications of the study and suggesting directions for future research.     

The role of passing network indicators in modeling football outcomes: an application using Bayesian hierarchical models

AStA Advances in Statistical Analysis - Passes are undoubtedly the more frequent events in football and other team sports. Passing networks and their structural features can be useful to evaluate...     

The Process of Job Creation and Job Destruction in the Italian Economy

ABSTRACT: Longitudinal analysis of labour flows provides a number of important indications on the characteristics of job creation and job destruction in the Italian economy, and on the role played by small firms in this process. The main indications may be summarized as follows: 1)the ratio of total separations to total work-force is remarkably high, and almost completely independent of the business cycle: one out of four workers leaves his/her position each year in the economy at large. In the small firms sector alone turnover is much higher, with total separations almost approaching 50|X% of employment; 2)as the economy takes a downturn, it is mainly the number of jobs created through expansion of existing firms that follows this cycle, while separations remain roughly constant; 3)the proportion of jobs created via the establishment of new firms is modest compared to that attributable to the expansion of existing plants (16.0-14.491)). Likewise, the proportion of job losses due to closures visi vis employment shedding by contracting firms, is of the same order of magnitude; 4)job creation and destruction is very high in the small firm sector. Employment in firms of dimension (0-19) is 25.8 % of total employment at the beginning of the observation period (1978) and reaches 28% at its end (1984). Yet the proportion of job creation attributable to small firms is approximately 60% of the new positions due to expansion of existing firms in manufacturing, and 68% in the services. The fraction of jobs destroyed by small firms is somewhat lower: about 46% in manufacturing and 59% in the services; 5)he small firms contribution to net job creation appears even more remarkable both in the aggregate, as well as within all sectors of economic activity and geographical areas. In 1978-80 net employment change in manufacturing is 106,000 units per year; correspondingly net job creation by firms (0-19) is alone 222,000. In the services the proportion between net employment change and the share of the small firms is 1:3. In 1981-83, while in manufacturing over 213,000 jobs are destroyed on average each year, net creation by small firms is still positive (+ 48,000); in the services the overall change is very small (+ 3,000), while the net contribution of small firms is + 53,000.