University of Pisa

Displaying 1-40 of 46 results

  • White Papers // Dec 2012

    Decision Assistance in Risk Assessment - Monte Carlo Simulations

    High security must be a primary and permanent concern of the leadership of an organization and it must be ensured at any time. For this, a risk analysis is compulsory and imperative to be done during the risk management cycle. Security risk analysis and security risk management components mostly use...

    Provided By University of Pisa

  • White Papers // Oct 2012

    Wireless Sensing Based on RFID and Capacitive Technologies for Safety in Marble Industry Process Control

    This paper presents wireless sensing systems to increase the safety and robustness in industrial process control, particularly in industrial machines for marble slab working. The experimented contact-less sensing systems are based on RFID and capacitive technologies. Their application has the final aim of detecting the presence of a marble slab...

    Provided By University of Pisa

  • White Papers // Apr 2012

    Uniform Obfuscation for Location Privacy

    As location-based services emerge, many people feel exposed to high privacy threats. Privacy protection is a major challenge for such applications. A broadly used approach is perturbation, which adds an artificial noise to positions and returns an obfuscated measurement to the requester. The authors' main finding is that, unless the...

    Provided By University of Pisa

  • White Papers // Apr 2012

    A Hybrid and Flexible Discovery Algorithm for Wireless Sensor Networks With Mobile Elements

    In sparse wireless sensor networks, data collection is carried out through specialized mobile nodes that visit sensor nodes, gather data, and transport them to the sink node. Since visit times are typically unpredictable, one of the main challenges to be faced in this kind of networks is the energy-efficient discovery...

    Provided By University of Pisa

  • White Papers // Feb 2012

    Secure Cooperation of Autonomous Mobile Sensors Using an Underwater Acoustic Network

    Methodologies and algorithms are presented for the secure cooperation of a team of autonomous mobile underwater sensors, connected through an acoustic communication network, within surveillance and patrolling applications. In particular, the work proposes a cooperative algorithm in which the mobile underwater sensors (installed on Autonomous Underwater Vehicles - AUVs) respond...

    Provided By University of Pisa

  • White Papers // Sep 2011

    Investigation of Scalable Video Delivery Using H.264 SVC on an LTE Network

    The combination of increased data rates in 4G cellular networks (such as LTE Advanced), dedicated multicast/broadcast services (e-MBMS) and the emergence of Scalable Video Coding standards (H.264 SVC) allow mobile operators to offer multimedia-based services with a high quality of experience to end users. H.264 SVC offers three dimensions of...

    Provided By University of Pisa

  • White Papers // May 2011

    On Experimentally Evaluating the Impact of Security on IEEE 802.15.4 Networks

    IEEE 802.15.4 addresses low-rate wireless personal area networks, enables low power devices, and includes a number of security provisions and options (the security sub-layer). Security competes with performance for the scarce resources of low power, low cost sensor devices. So, a proper design of efficient and secure applications requires to...

    Provided By University of Pisa

  • White Papers // Apr 2011

    Reliable Data Delivery in Sparse WSNs With Multiple Mobile Sinks: An Experimental Analysis

    Urban sensing is emerging as a significant Wireless Sensor Networks (WSNs) application. In such a scenario, static sensors are sparsely deployed in a urban area to collect environmental information. Sensed data are opportunistically collected by Mobile Sinks (MSs), which can be other sensor nodes attached to cars or buses, or...

    Provided By University of Pisa

  • White Papers // Jan 2011

    A Corporate Model of Similitude for SMEs Reunion Into a Corporation, Viewed From the Angle of Physical Thought, and Its Complex Economic and Social Impact

    In order to exceed the circularity of formal economic thinking, the authors of the present paper favor the models of thinking specific to physics, which are also constructed statistically and mathematically, in an attempt to find an answer to the reunion of similar Small and Medium Enterprises (SMEs), into multinational...

    Provided By University of Pisa

  • White Papers // Jan 2011

    Network Dynamics in Regional Clusters: A New Perspective From an Emerging Economy

    Regional clusters are spatial agglomerations of firms operating in the same or connected industries, which enable innovation and economic performance for firms. A wealth of empirical literature shows that one of key elements of the success of regional clusters is that they facilitate the formation of local inter-organizational networks, which...

    Provided By University of Pisa

  • White Papers // Jan 2011

    Using Clustering and Blade Clusters in the TeraByte Task

    Web search engines exploit conjunctive queries and special ranking criteria which differ from the disjunctive queries typically used for ad-hoc retrieval. The authors wanted to asses the effectiveness of those techniques in the TeraByte task, in particular scoring criteria like: Link popularity, proximity boosting, home page score, descriptions and anchor...

    Provided By University of Pisa

  • White Papers // Jan 2011

    Types and Effects for Secure Service Orchestration

    A distributed calculus is proposed for describing networks of services. The authors model service interaction through a call-by-property invocation mechanism, by specifying the security constraints that make their composition safe. A static approach is then proposed to determine how to compose services and guarantee that their execution is always secure,...

    Provided By University of Pisa

  • White Papers // Jan 2011

    Security Issues in Service Composition

    The authors use a distributed, enriched ?-calculus for describing networks of services. Both services and the clients can protect themselves, by imposing security constraints on each other's behaviour. Then, service interaction results in a call-by-property mechanism that matches the client requests with services. A static approach is also described, that...

    Provided By University of Pisa

  • White Papers // Jan 2011

    Housing Tenure And Job Search Behaviour. A Different Analysis Of The Impact Of The UK Jobseeker~s Allowance

    This paper investigates the relation between job search effort and housing tenure by focussing on the impact of the UK Jobseeker's Allowance reform introduced in the UK in 1996. Theory suggests that a tightening in job search requirements, as implied by this reform, raises movements o benefit of non-employed with...

    Provided By University of Pisa

  • White Papers // Dec 2010

    Programming a Sensor Network in a Layered Middleware Architecture

    Wireless Sensor Networks (WSNs) have become a mature technology aimed at performing environmental monitoring and data collection. Nonetheless, harnessing the power of a WSN presents a number of research challenges. WSN application developers have to deal both with the business logic of the application and with WSN's issues, such as...

    Provided By University of Pisa

  • White Papers // Dec 2010

    Multidomain Layer 1 Infrastructure Virtualization as a Future Internet Services-Enabling Paradigm

    NGNs are being envisioned to circumvent the ossification of current Internet and leverage advanced and profitable Future Internet services. It is still unclear how this will be realized, but network infrastructure virtualization continues to gain momentum as an elegant solution to accommodate concurrent NGNs in a flexible, robust fashion. Despite...

    Provided By University of Pisa

  • White Papers // Nov 2010

    A New Statistical Approach to Network Anomaly Detection

    In the last few years, the number and impact of security attacks over the Internet have been continuously increasing. To face this issue, the use of Intrusion Detection Systems (IDSs) has emerged as a key element in network security. In this paper the authors address the problem considering a novel...

    Provided By University of Pisa

  • White Papers // Oct 2010

    Safer in the Clouds

    In the old times, people used to exploit the bakery's oven for their home-made bread. Similarly, people utilised the public mill to obtain flour from their wheat. In both cases, people did not own the physical infrastructure to process their products, neither had they invested on it. Instead, they rented...

    Provided By University of Pisa

  • White Papers // Oct 2010

    A Comprehensive Analysis of the MAC Unreliability Problem in IEEE 802.15.4 Wireless Sensor Networks

    Wireless Sensor Networks (WSNs) represent a very promising solution in the field of wireless technologies for industrial applications. However, for a credible deployment of WSNs in an industrial environment, four main properties need to be fulfilled, i.e., energy efficiency, scalability, reliability, and timeliness. In this paper, the authors focus on...

    Provided By University of Pisa

  • White Papers // Sep 2010

    Labour Incentive Schemes In A Cournot Duopoly With Simple Institutional Constraints

    This paper studies equilibrium incentive contracts in a Cournot duopoly, in which institutional arrangements constrain firms to pay (risk-neutral) workers a given salary. In this context, Performance-Related-Pay (PRP) and Relative Performance Evaluation (RPE) are compared in terms of resulting levels of workers' effort (firms' expected output), market price, profits, consumer...

    Provided By University of Pisa

  • White Papers // Aug 2010

    Adaptive Subframe Allocation in WiMAX Networks

    Recently, a promising technology called WiMAX is providing wireless last-mile connectivity due to its high speed data rates, low cost of deployment, and large coverage area. However, capacity allocation between uplink and downlink subframes is a system parameter that should be determined based on the expected traffic conditions. In this...

    Provided By University of Pisa

  • White Papers // Jul 2010

    VirtuaLinux Design Principles

    VirtuaLinux is a Linux meta-distribution that allows the creation, deployment and administration of both physical and virtualized clusters with no single point of failure. They are avoided by means of a combination of architectural, software and hardware strategies, including the transparent support for disk-less and master-less cluster configuration. VirtuaLinux support...

    Provided By University of Pisa

  • White Papers // May 2010

    Using AMC and HARQ to Optimize System Capacity and Application Delays in WiMAX Networks

    The IEEE 802.16 technology (WiMAX) is a promising alternative to 3G or wireless LAN for providing last-mile connectivity by radio link due to its large coverage area, low cost of deployment and high speed data rates. The standard specifies the air-interface between a Subscriber Station (SS) and a Base Station...

    Provided By University of Pisa

  • White Papers // Apr 2010

    Reliability and Energy Efficiency in Multi-Hop IEEE 802.15.4/ZigBee Wireless Sensor Networks

    Wireless Sensor Networks (WSNs) are a very appealing solution for many practical applications. Recently, WSNs have also been deployed in industrial scenarios, even for critical applications. Two major requirements are needed for an effective deployment of WSNs in such scenarios. The first is energy efficiency, as a network lifetime in...

    Provided By University of Pisa

  • White Papers // Apr 2010

    Data Centric Storage in ZigBee Wireless Sensor Networks

    Data Centric Storage is a recent paradigm that results more efficient than other storage techniques (such as local or external storage) in Wireless Sensor Networks (WSN). In this paper, the authors consider the use of this storage paradigm in WSN based on the ZigBee standard. In particular they propose a...

    Provided By University of Pisa

  • White Papers // Apr 2010

    Measuring Data and VoIP Traffic in WiMAX Networks

    Due to its large coverage area, low cost of deployment and high speed data rates, WiMAX is a promising technology for providing wireless last-mile connectivity. Physical and MAC layer of this technology refer to the IEEE 802.16e standard, which defines 5 different data delivery service classes that can be used...

    Provided By University of Pisa

  • White Papers // Jan 2010

    Data Warehouses Security Implementation

    Data warehouses were initially implemented and developed by the big firms and they were used for working out the managerial problems and for making decisions. Later on, because of the economic tendencies and of the technological progress, the data warehouses could also be set up by the medium and small...

    Provided By University of Pisa

  • White Papers // Dec 2009

    Fertility And Public Debt

    Public debt and fertility are two issues of major concern in the current debate about economic policy, especially in countries with below replacement fertility and large debt. In this paper, the authors show that public debt is in general harmful for fertility, in that debt issuing almost ever crowds out...

    Provided By University of Pisa

  • White Papers // Nov 2009

    From Wage Rigidities To Labour Market Rigidities: A Turning-Point In Explaining Equilibrium Unemployment?

    This paper offers a critical discussion of the concept of labour market rigidity relevant to explaining unemployment. Starting from Keynes's own view, the authors discuss how the concept of labour market flexibility has changed over time, involving nominal or real wage flexibility, contract flexibility or labour market institution flexibility. They...

    Provided By University of Pisa

  • White Papers // Oct 2009

    Child Policy Ineffectiveness In An OLG Small Open Economy With Human Capital Accumulation And Public Education

    Motivated by the recent decrease in the number of children experienced in many developed countries, in this paper the authors consider an OLG small open economy with endogenous fertility and human capital formation through public education and look at the role the government can play in affecting fertility rates through...

    Provided By University of Pisa

  • White Papers // Oct 2009

    The Impact Of Public Funding For Innovation On Firms~ R&D Investments: Do R&D Cooperation And Appropriability Matter?

    This paper provides a theoretical and empirical framework to explore how public funding affects firms' R&D investments depending on their engagement in horizontal R&D co-operations and different levels of appropriability conditions within the economy. It assumes firms' Cournot-Nash behavior in the choice of the optimal R&D investment level and provides...

    Provided By University of Pisa

  • White Papers // Oct 2009

    Financing Decisions: Convertibles, Taxes And Credit Risk

    While much theoretical and empirical research examines the issuer's choice between straight debt and equity, little attention has been paid to the choice relating to convertible bonds. The aim of this paper is to propose a rational model that will aid managers or issuers to decide between convertibles and stock...

    Provided By University of Pisa

  • White Papers // Oct 2009

    Endogenous Fertility, Endogenous Lifetime And Economic Growth: The Role Of Health And Child Policies

    In this paper the authors link endogenous fertility, endogenous longevity, economic growth and public policies - represented by public health investments and child policies - in a basic overlapping generations model. They found that there even exist four equilibria, and thus low and high development regimes, which may be, however,...

    Provided By University of Pisa

  • White Papers // Jun 2009

    Publish/subscribe in Wireless Sensor Networks Based on Data Centric Storage

    The rapid development of Wireless Sensor Networks (WSN) technologies gave rise to the need for abstraction mechanisms that can simplify the data management tasks. Under this respect, the publish/subscribe paradigms play an important role since they can be used to abstract the WSN in terms that are closer to applicative...

    Provided By University of Pisa

  • White Papers // Jun 2009

    Reliable and Energy-Efficient Data Collection in Sparse Sensor Networks With Mobile Elements

    Sparse Wireless Sensor Networks (WSNs) are emerging as an effective solution for a wide range of applications, especially for environmental monitoring. In many scenarios, a moderate number of sparsely deployed nodes can be sufficient to get the required information about the sensed phenomenon. To this end, special mobile elements, i.e....

    Provided By University of Pisa

  • White Papers // Jun 2009

    Set - Valued Consensus for Distributed Clock Synchronization

    This paper addresses the clock synchronization problem in a Wireless Sensor Network (WSN) and proposes a distributed solution that consists of a form of consensus, where agents are able to exchange data representing intervals or sets. The solution is based on a centralized algorithm for clock synchronization, proposed by Marzullo,...

    Provided By University of Pisa

  • White Papers // May 2009

    Distributed Erasure Coding in Data Centric Storage for Wireless Sensor Networks

    In-network storage of data in wireless sensor networks contributes to reduce the communications inside the network and to favor data aggregation. In this paper, the authors consider the use of erasure codes in combination to in-network storage. They provide an abstract model of in-network storage to show how erasure codes...

    Provided By University of Pisa

  • White Papers // May 2009

    Right-to-manage Unions Endogenous Growth And Welfare

    Using the basic overlapping generations one-sector model of endogenous growth the authors show that unionisation of labour markets may be growth-enhancing with respect to the standard competitive equilibrium economy with full employment, provided the capital's weight in technology and the replacement rate are both high enough. Moreover, a growth-maximising value...

    Provided By University of Pisa

  • White Papers // Apr 2009

    Transitions Out Of Unemployment: The Role Of Social Networks~ Topology And Firms~ Recruitment Strategies

    In this paper the authors adopt the probabilistic framework of Calvo-Armengol and Jackson (2004) to study the effects of job contact networks on out-of-unemployment transitions. In particular they evaluate the role of different network topologies vis-a-vis state-dependent probabilities of receiving information on vacancies, which they relate to different firms' recruitment...

    Provided By University of Pisa

  • White Papers // Jan 2009

    DiffServ Traffic Management With MPLS

    This paper describes a proportional differentiated services architecture based on MPLS constraint based routing for traffic engineering. Three classes are defined: Gold, Silver and Bronze. The Gold class gets the best service and, whenever possible, the double of the bandwidth of the Silver class. The Bronze class is a best...

    Provided By University of Pisa

  • White Papers // Dec 2010

    Multidomain Layer 1 Infrastructure Virtualization as a Future Internet Services-Enabling Paradigm

    NGNs are being envisioned to circumvent the ossification of current Internet and leverage advanced and profitable Future Internet services. It is still unclear how this will be realized, but network infrastructure virtualization continues to gain momentum as an elegant solution to accommodate concurrent NGNs in a flexible, robust fashion. Despite...

    Provided By University of Pisa

  • White Papers // Dec 2009

    Fertility And Public Debt

    Public debt and fertility are two issues of major concern in the current debate about economic policy, especially in countries with below replacement fertility and large debt. In this paper, the authors show that public debt is in general harmful for fertility, in that debt issuing almost ever crowds out...

    Provided By University of Pisa

  • White Papers // Nov 2010

    A New Statistical Approach to Network Anomaly Detection

    In the last few years, the number and impact of security attacks over the Internet have been continuously increasing. To face this issue, the use of Intrusion Detection Systems (IDSs) has emerged as a key element in network security. In this paper the authors address the problem considering a novel...

    Provided By University of Pisa

  • White Papers // Oct 2010

    Safer in the Clouds

    In the old times, people used to exploit the bakery's oven for their home-made bread. Similarly, people utilised the public mill to obtain flour from their wheat. In both cases, people did not own the physical infrastructure to process their products, neither had they invested on it. Instead, they rented...

    Provided By University of Pisa

  • White Papers // May 2010

    Using AMC and HARQ to Optimize System Capacity and Application Delays in WiMAX Networks

    The IEEE 802.16 technology (WiMAX) is a promising alternative to 3G or wireless LAN for providing last-mile connectivity by radio link due to its large coverage area, low cost of deployment and high speed data rates. The standard specifies the air-interface between a Subscriber Station (SS) and a Base Station...

    Provided By University of Pisa

  • White Papers // Apr 2010

    Measuring Data and VoIP Traffic in WiMAX Networks

    Due to its large coverage area, low cost of deployment and high speed data rates, WiMAX is a promising technology for providing wireless last-mile connectivity. Physical and MAC layer of this technology refer to the IEEE 802.16e standard, which defines 5 different data delivery service classes that can be used...

    Provided By University of Pisa

  • White Papers // Aug 2010

    Adaptive Subframe Allocation in WiMAX Networks

    Recently, a promising technology called WiMAX is providing wireless last-mile connectivity due to its high speed data rates, low cost of deployment, and large coverage area. However, capacity allocation between uplink and downlink subframes is a system parameter that should be determined based on the expected traffic conditions. In this...

    Provided By University of Pisa

  • White Papers // Apr 2011

    Reliable Data Delivery in Sparse WSNs With Multiple Mobile Sinks: An Experimental Analysis

    Urban sensing is emerging as a significant Wireless Sensor Networks (WSNs) application. In such a scenario, static sensors are sparsely deployed in a urban area to collect environmental information. Sensed data are opportunistically collected by Mobile Sinks (MSs), which can be other sensor nodes attached to cars or buses, or...

    Provided By University of Pisa

  • White Papers // Jun 2009

    Set - Valued Consensus for Distributed Clock Synchronization

    This paper addresses the clock synchronization problem in a Wireless Sensor Network (WSN) and proposes a distributed solution that consists of a form of consensus, where agents are able to exchange data representing intervals or sets. The solution is based on a centralized algorithm for clock synchronization, proposed by Marzullo,...

    Provided By University of Pisa

  • White Papers // Apr 2010

    Data Centric Storage in ZigBee Wireless Sensor Networks

    Data Centric Storage is a recent paradigm that results more efficient than other storage techniques (such as local or external storage) in Wireless Sensor Networks (WSN). In this paper, the authors consider the use of this storage paradigm in WSN based on the ZigBee standard. In particular they propose a...

    Provided By University of Pisa

  • White Papers // May 2009

    Distributed Erasure Coding in Data Centric Storage for Wireless Sensor Networks

    In-network storage of data in wireless sensor networks contributes to reduce the communications inside the network and to favor data aggregation. In this paper, the authors consider the use of erasure codes in combination to in-network storage. They provide an abstract model of in-network storage to show how erasure codes...

    Provided By University of Pisa

  • White Papers // Jun 2009

    Publish/subscribe in Wireless Sensor Networks Based on Data Centric Storage

    The rapid development of Wireless Sensor Networks (WSN) technologies gave rise to the need for abstraction mechanisms that can simplify the data management tasks. Under this respect, the publish/subscribe paradigms play an important role since they can be used to abstract the WSN in terms that are closer to applicative...

    Provided By University of Pisa

  • White Papers // Jun 2008

    Information Assurance in Critical Infrastructures Via Wireless Sensor Networks

    Information assurance in critical infrastructure is an issue that has been addressed generally focusing on real-time or quasi real-time monitoring of the critical infrastructure; so that action could be undertaken when anomalies arise, to avoid more severe consequences to the infrastructure. In this paper, the authors relax the hypothesis of...

    Provided By University of Pisa

  • White Papers // Jul 2008

    A Secure Middleware for Wireless Sensor Networks

    SMEPP Light is a middleware for Wireless Sensor Networks (WSNs) based on mote-class sensors. It is derived from the specification developed under the framework of the SMEPP project, to deal with the hardware and software constraints of WSNs. SMEPP Light features group management, group-level security policies, mechanisms for query injection...

    Provided By University of Pisa

  • White Papers // Dec 2010

    Programming a Sensor Network in a Layered Middleware Architecture

    Wireless Sensor Networks (WSNs) have become a mature technology aimed at performing environmental monitoring and data collection. Nonetheless, harnessing the power of a WSN presents a number of research challenges. WSN application developers have to deal both with the business logic of the application and with WSN's issues, such as...

    Provided By University of Pisa

  • White Papers // Sep 2011

    Investigation of Scalable Video Delivery Using H.264 SVC on an LTE Network

    The combination of increased data rates in 4G cellular networks (such as LTE Advanced), dedicated multicast/broadcast services (e-MBMS) and the emergence of Scalable Video Coding standards (H.264 SVC) allow mobile operators to offer multimedia-based services with a high quality of experience to end users. H.264 SVC offers three dimensions of...

    Provided By University of Pisa

  • White Papers // Apr 2012

    Uniform Obfuscation for Location Privacy

    As location-based services emerge, many people feel exposed to high privacy threats. Privacy protection is a major challenge for such applications. A broadly used approach is perturbation, which adds an artificial noise to positions and returns an obfuscated measurement to the requester. The authors' main finding is that, unless the...

    Provided By University of Pisa

  • White Papers // Feb 2012

    Secure Cooperation of Autonomous Mobile Sensors Using an Underwater Acoustic Network

    Methodologies and algorithms are presented for the secure cooperation of a team of autonomous mobile underwater sensors, connected through an acoustic communication network, within surveillance and patrolling applications. In particular, the work proposes a cooperative algorithm in which the mobile underwater sensors (installed on Autonomous Underwater Vehicles - AUVs) respond...

    Provided By University of Pisa

  • White Papers // May 2011

    On Experimentally Evaluating the Impact of Security on IEEE 802.15.4 Networks

    IEEE 802.15.4 addresses low-rate wireless personal area networks, enables low power devices, and includes a number of security provisions and options (the security sub-layer). Security competes with performance for the scarce resources of low power, low cost sensor devices. So, a proper design of efficient and secure applications requires to...

    Provided By University of Pisa

  • White Papers // Oct 2009

    Endogenous Fertility, Endogenous Lifetime And Economic Growth: The Role Of Health And Child Policies

    In this paper the authors link endogenous fertility, endogenous longevity, economic growth and public policies - represented by public health investments and child policies - in a basic overlapping generations model. They found that there even exist four equilibria, and thus low and high development regimes, which may be, however,...

    Provided By University of Pisa

  • White Papers // Nov 2009

    From Wage Rigidities To Labour Market Rigidities: A Turning-Point In Explaining Equilibrium Unemployment?

    This paper offers a critical discussion of the concept of labour market rigidity relevant to explaining unemployment. Starting from Keynes's own view, the authors discuss how the concept of labour market flexibility has changed over time, involving nominal or real wage flexibility, contract flexibility or labour market institution flexibility. They...

    Provided By University of Pisa

  • White Papers // Jan 2011

    Using Clustering and Blade Clusters in the TeraByte Task

    Web search engines exploit conjunctive queries and special ranking criteria which differ from the disjunctive queries typically used for ad-hoc retrieval. The authors wanted to asses the effectiveness of those techniques in the TeraByte task, in particular scoring criteria like: Link popularity, proximity boosting, home page score, descriptions and anchor...

    Provided By University of Pisa

  • White Papers // Jan 2011

    Types and Effects for Secure Service Orchestration

    A distributed calculus is proposed for describing networks of services. The authors model service interaction through a call-by-property invocation mechanism, by specifying the security constraints that make their composition safe. A static approach is then proposed to determine how to compose services and guarantee that their execution is always secure,...

    Provided By University of Pisa

  • White Papers // May 2009

    Right-to-manage Unions Endogenous Growth And Welfare

    Using the basic overlapping generations one-sector model of endogenous growth the authors show that unionisation of labour markets may be growth-enhancing with respect to the standard competitive equilibrium economy with full employment, provided the capital's weight in technology and the replacement rate are both high enough. Moreover, a growth-maximising value...

    Provided By University of Pisa

  • White Papers // Oct 2009

    Financing Decisions: Convertibles, Taxes And Credit Risk

    While much theoretical and empirical research examines the issuer's choice between straight debt and equity, little attention has been paid to the choice relating to convertible bonds. The aim of this paper is to propose a rational model that will aid managers or issuers to decide between convertibles and stock...

    Provided By University of Pisa

  • White Papers // Apr 2010

    Reliability and Energy Efficiency in Multi-Hop IEEE 802.15.4/ZigBee Wireless Sensor Networks

    Wireless Sensor Networks (WSNs) are a very appealing solution for many practical applications. Recently, WSNs have also been deployed in industrial scenarios, even for critical applications. Two major requirements are needed for an effective deployment of WSNs in such scenarios. The first is energy efficiency, as a network lifetime in...

    Provided By University of Pisa

  • White Papers // Oct 2010

    A Comprehensive Analysis of the MAC Unreliability Problem in IEEE 802.15.4 Wireless Sensor Networks

    Wireless Sensor Networks (WSNs) represent a very promising solution in the field of wireless technologies for industrial applications. However, for a credible deployment of WSNs in an industrial environment, four main properties need to be fulfilled, i.e., energy efficiency, scalability, reliability, and timeliness. In this paper, the authors focus on...

    Provided By University of Pisa

  • White Papers // Jun 2009

    Reliable and Energy-Efficient Data Collection in Sparse Sensor Networks With Mobile Elements

    Sparse Wireless Sensor Networks (WSNs) are emerging as an effective solution for a wide range of applications, especially for environmental monitoring. In many scenarios, a moderate number of sparsely deployed nodes can be sufficient to get the required information about the sensed phenomenon. To this end, special mobile elements, i.e....

    Provided By University of Pisa

  • White Papers // Apr 2012

    A Hybrid and Flexible Discovery Algorithm for Wireless Sensor Networks With Mobile Elements

    In sparse wireless sensor networks, data collection is carried out through specialized mobile nodes that visit sensor nodes, gather data, and transport them to the sink node. Since visit times are typically unpredictable, one of the main challenges to be faced in this kind of networks is the energy-efficient discovery...

    Provided By University of Pisa

  • White Papers // Jul 2008

    Energy Conservation in Wireless Sensor Networks: A Survey

    In the last years, Wireless Sensor Networks (WSNs) have gained increasing attention from both the research community and actual users. As sensor nodes are generally battery-powered devices, the critical aspects to face concern how to reduce the energy consumption of nodes, so that the network lifetime can be extended to...

    Provided By University of Pisa

  • White Papers // Jul 2010

    VirtuaLinux Design Principles

    VirtuaLinux is a Linux meta-distribution that allows the creation, deployment and administration of both physical and virtualized clusters with no single point of failure. They are avoided by means of a combination of architectural, software and hardware strategies, including the transparent support for disk-less and master-less cluster configuration. VirtuaLinux support...

    Provided By University of Pisa

  • White Papers // Jan 2011

    Security Issues in Service Composition

    The authors use a distributed, enriched ?-calculus for describing networks of services. Both services and the clients can protect themselves, by imposing security constraints on each other's behaviour. Then, service interaction results in a call-by-property mechanism that matches the client requests with services. A static approach is also described, that...

    Provided By University of Pisa

  • White Papers // Jan 2011

    Network Dynamics in Regional Clusters: A New Perspective From an Emerging Economy

    Regional clusters are spatial agglomerations of firms operating in the same or connected industries, which enable innovation and economic performance for firms. A wealth of empirical literature shows that one of key elements of the success of regional clusters is that they facilitate the formation of local inter-organizational networks, which...

    Provided By University of Pisa

  • White Papers // May 2008

    Neoclassical Economic Growth And Lifetime Welfare In A Simple OLG Model With Unions

    The authors analyse the effects of the introduction of a unionised labour market in a simple Diamond's OLG framework. Interesting findings, so far escaped closer scrutiny, emerge. Under some particular conditions about the key parameters of the model, the unionised-wage economy may perform better than the standard market-clearing wage frame...

    Provided By University of Pisa

  • White Papers // Apr 2009

    Transitions Out Of Unemployment: The Role Of Social Networks~ Topology And Firms~ Recruitment Strategies

    In this paper the authors adopt the probabilistic framework of Calvo-Armengol and Jackson (2004) to study the effects of job contact networks on out-of-unemployment transitions. In particular they evaluate the role of different network topologies vis-a-vis state-dependent probabilities of receiving information on vacancies, which they relate to different firms' recruitment...

    Provided By University of Pisa

  • White Papers // Oct 2009

    Child Policy Ineffectiveness In An OLG Small Open Economy With Human Capital Accumulation And Public Education

    Motivated by the recent decrease in the number of children experienced in many developed countries, in this paper the authors consider an OLG small open economy with endogenous fertility and human capital formation through public education and look at the role the government can play in affecting fertility rates through...

    Provided By University of Pisa

  • White Papers // Oct 2009

    The Impact Of Public Funding For Innovation On Firms~ R&D Investments: Do R&D Cooperation And Appropriability Matter?

    This paper provides a theoretical and empirical framework to explore how public funding affects firms' R&D investments depending on their engagement in horizontal R&D co-operations and different levels of appropriability conditions within the economy. It assumes firms' Cournot-Nash behavior in the choice of the optimal R&D investment level and provides...

    Provided By University of Pisa

  • White Papers // Jan 2011

    Housing Tenure And Job Search Behaviour. A Different Analysis Of The Impact Of The UK Jobseeker~s Allowance

    This paper investigates the relation between job search effort and housing tenure by focussing on the impact of the UK Jobseeker's Allowance reform introduced in the UK in 1996. Theory suggests that a tightening in job search requirements, as implied by this reform, raises movements o benefit of non-employed with...

    Provided By University of Pisa

  • White Papers // Sep 2010

    Labour Incentive Schemes In A Cournot Duopoly With Simple Institutional Constraints

    This paper studies equilibrium incentive contracts in a Cournot duopoly, in which institutional arrangements constrain firms to pay (risk-neutral) workers a given salary. In this context, Performance-Related-Pay (PRP) and Relative Performance Evaluation (RPE) are compared in terms of resulting levels of workers' effort (firms' expected output), market price, profits, consumer...

    Provided By University of Pisa

  • White Papers // Oct 2012

    Wireless Sensing Based on RFID and Capacitive Technologies for Safety in Marble Industry Process Control

    This paper presents wireless sensing systems to increase the safety and robustness in industrial process control, particularly in industrial machines for marble slab working. The experimented contact-less sensing systems are based on RFID and capacitive technologies. Their application has the final aim of detecting the presence of a marble slab...

    Provided By University of Pisa