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Every day the number of devices interacting through telecommunications networks grows resulting into an increase in the volume of data and information generated. At the same time, a growing number of information security incidents is being observed including the occurrence of unauthorized accesses, also named intrusions. As a consequence of these two developments, Information and Communications services providers require automated processes to detect and solve such intrusions, and this should done quickly in order to keep the related cybersecurity risks at acceptable levels. However, the presence of large volumes of data negatively interferes with the performance of classifiers used in intrusion detection tasks, which limits their applicability in practical cases. The research reported in this paper focuses on proposing a novel feature selection algorithm for intrusion detection scenarios. To this end, an extensive literature review was executed to first discover issues in the feature selection algorithms reported. Based on the insights obtained, the new multi-measure feature selection algorithm was designed that uses qualitative information provided by multiple feature selection measures, and reduces the dimensionality of the training data set. The algorithm proposed was next extensively tested using various data sets. It provides greater efficacy than other feature selection algorithms used for intrusion detection purposes. We finalize by providing some ideas on future research in order to further improve the algorithm., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Information and Communication Technology

For most people, cybersecurity is a difficult notion to grasp. Traditionally, cybersecurity has been considered a technical challenge, and still many specialists understand it as information security, with the notions of confidentiality, integrity, and availability as its foundation. Although many have searched for different and broader perspectives, the complexity and ambiguity of the notion still thwarts a common understanding. While the author was developing and executing a MSc cybersecurity program for professionals with a wide variety of backgrounds and widely differing views on cybersecurity, the lack of a common understanding of cybersecurity was clearly evident. Based on these observations, the author began seeking and defining a new, transdisciplinary conceptualization of cybersecurity that can be widely agreed upon. It resulted in the publication of three scientific papers. This paper is an amalgam of the contents of the three supplemented with some extensions. It turned out that the previously introduced description of two key notions, cyberspace and cybersecurity, is still an adequate starting point. Described here is a set of additional mental models elaborating on these key notions and providing more detail on their meanings. The research suggests that this set of mental models strongly supports the description and analysis of current cybersecurity challenges and helps people understand how everyone, in his or her various roles, can contribute to reducing the related cyber risks. These claims are supported by presenting the modeling and analysis approaches of various MSc-thesis research projects executed by students when working on practical cybersecurity problems both within and outside their organisations. The author further discovered that, for a limited set of cybersecurity challenges, it was not yet possible to identify adequate mental models; this defines the agenda for future research., Information and Communication Technology, Cyber Security

Cyber operations are relatively a new phenomenon of the last two decades. During that period, they have increased in number, complexity, and agility, while their design and development have been processes well kept under secrecy. As a consequence, limited data(sets) regarding these incidents are available. Although various academic and practitioner public communities addressed some of the key points and dilemmas that surround cyber operations (such as attack, target identification and selection, and collateral damage), still methodologies and models are needed in order to plan, execute, and assess them in a responsibly and legally compliant way. Based on these facts, it is the aim of this article to propose a model that i)) estimates and classifies the effects of cyber operations, and ii) assesses proportionality in order to support targeting decisions in cyber operations. In order to do that, a multi-layered fuzzy model was designed and implemented by analysing real and virtual realistic cyber operations combined with interviews and focus groups with technical – military experts. The proposed model was evaluated on two cyber operations use cases in a focus group with four technical – military experts. Both the design and the results of the evaluation are revealed in this article., Information and Communication Technology, Organisation and Governance

Cyber Operations stopped being utopia or Sci-Fi based scenarios: they became reality. When planning and conducting them, military actors encounter difficulties since they lack methodologies and models that support their actions and assess their effects. To address these issues by tackling the underlying scientific and practical gap, this article proposes an assessment methodology for the intended and unintended effects of Cyber Operations, labeled as Military Advantage, Collateral Damage and Military Disadvantage, and aims at supporting the targeting process when engaging targets in Cyber Operations. To arrive at this methodology, an extensive review on literature, military doctrine and methodologies was conducted combined with two series of interviews with military commanders and field work in joint military exercises. The assessment methodology is proposed considering multidimensional factors, phases and steps in a technical - military approach. For validation, one realistic Cyber Operation case study was conducted in a focus group with nine military experts plus four face-to-face meetings with another four military experts., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Information and Communication Technology, Organisation and Governance

For most people, cybersecurity is a hard to grasp notion. Traditionally, cybersecurity has been considered as a technical challenge and still many specialists view it equivalent with information security, with the notions of confidentiality, integrity and availability as starting points of thinking. And although others searched for a broader perspective, the complexity and ambiguity of the notion still thwarts a common understanding. While developing and executing a MSc cybersecurity program for professionals, the lack of a common understanding of what cybersecurity entails was again observed. Stimulated by this, we started to look for and define a new, transdisciplinary conceptualization of cybersecurity that everyone can agree upon. It resulted in two scientific papers published. This paper describes the outcomes of the continuation of our research journey. It turned out that the earlier introduced description of two key notions, namely that of cyberspace and that of cybersecurity, can still be considered as adequate starting points. Here, we describe a set of additional mental models that elaborates them and provides more detail to the meaning of the two key notions. In practice, it turned out that the additional mental models strongly support the description and analysis of existing and upcoming cybersecurity challenges and helps to understand how everybody, in his or her various roles, can or should contribute to reducing the related cyber risks to adequate levels. We further discovered that for certain cybersecurity challenges, especially those related to efficient cyber risk mitigation, we could not yet identify an adequate sub-set of mental models. This defines the agenda for near future cybersecurity research., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Information and Communication Technology

In the last few years, the telecommunications scenario has experienced an increase in the volume of information generated, as well as in the execution of malicious activities. In order to complement Intrusion Detection Systems (IDSs), data mining techniques have begun to play a fundamental role in data analysis. On the other hand, the presence of useless information and the amount of data generated by telecommunication services (leading to a huge dimensional problem), can affect the performance of traditional IDSs. In this sense, a data preprocessing strategy is necessary to reduce data, but reducing data without affecting the accuracy of IDSs represents a challenge. In this paper, we propose a new data preprocessing strategy which reduces the number of features and instances in the training collection without greatly affecting the achieved accuracy of IDSs. Finally, our proposal is evaluated using four different rule-based classifiers, which are tested on real scan and backscatter data collected by a network telescope., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Information and Communication Technology, Cyber Security

Cyber operations lack models, methodologies, and mechanisms to describe relevant data and knowledge. This problem is directly reflected when cyber operations are conducted and their effects assessed, and it can produce dissonance and disturbance in corresponding decision-making processes and communication between different military actors. To tackle these issues, this article proposes a knowledge model for cyber operations implemented as a computational ontology following a design science approach grounded on extensive technical-military research. This model classifies the essential entities of cyber operations and is exemplified in three case studies. Validation results show that this model can be used to describe cyber operations clearly and concisely., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Information and Communication Technology, Organisation and Governance, Cyber Security

The 2013 National Security Agency revelations of pervasive monitoring have led to an "encryption rush" across the computer and Internet industry. To push back against massive surveillance and protect users' privacy, vendors, hosting and cloud providers have widely deployed encryption on their hardware, communication links, and applications. As a consequence, most web connections nowadays are encrypted. However, there is still a significant part of Internet traffic that is not encrypted. It has been argued that both costs and complexity associated with obtaining and deploying X.509 certificates are major barriers for widespread encryption, since these certificates are required to establish encrypted connections. To address these issues, the Electronic Frontier Foundation, Mozilla Foundation, the University of Michigan and a number of partners have set up Let's Encrypt (LE), a certificate authority that provides both free X.509 certificates and software that automates the deployment of these certificates. In this paper, we investigate if LE has been successful in democratizing encryption: we analyze certificate issuance in the first year of LE and show from various perspectives that LE adoption has an upward trend and it is in fact being successful in covering the lower-cost end of the hosting market., Organisation and Governance, Cyber Security, Information and Communication Technology

Today’s increasing connectivity creates cyber risks at personal, organizational up to societal level. Societal cyber risks require mitigation by all kinds of actors where government should take the lead due to its responsibility to protect its citizens. Since no formal global governance exists, the governmental responsibility should start at the national level of every country. To achieve successful management of global cyber risks, appropriate alignment between these sovereignly developed strategies is required, which concerns a complex challenge. To create alignment, getting insight into differences between national cyber strategies, is the first step. This, in turn, requires an appropriate analysis approach that helps to identify the key differences. In this article, we introduce such an analysis approach based on social contract theory. The resulting analysis model consists of both a direct and an indirect type of social cyber contract between governments, citizens and corporations, within and between sovereign nations. To show its effectiveness, the proposed social cyber contract model is validated through an illustrated case examining various constitutional rights to privacy, their embedding in the national cyber strategies and how their differences could cause potential barriers for alignment across sovereignties., Information and Communication Technology, Organisation and Governance, Cyber Security

Low-voltage distribution grids experience a rising penetration of inverter-based, distributed generation. In order to not only contribute to but also solve voltage problems, these inverters are increasingly asked to participate in intelligent grid controls. Communicating inverters implement distributed voltage droop controls. The impact of cyber-attacks to the stability of such distributed grid controls is poorly researched and therefore addressed in this article. We characterize the potential impact of several attack scenarios by employing the positivity and diagonal dominance properties. In particular, we discuss measurement falsification scenarios where the attacker corrupts voltage measurement data received by the voltage droop controllers. Analytical, control-theoretic methods for assessing the impact on system stability and voltage magnitude are presented and validated via simulation., Intelligent Electrical Power Grids, Information and Communication Technology, Cyber Security

De termen “informatiebeveiliging” en “cyber security” worden vaak door elkaar gebruikt soms met dezelfde, soms met een afwijkende betekenis. Velen spreken vandaag de dag ook over cyberspace, bijvoorbeeld als een nieuw (door de mens gecreëerd) vijfde domein naast de bestaande domeinen land, water, lucht en ruimte. Een en ander roept de vraag op of informatiebeveiliging en cyber security (wel of niet) fundamenteel van elkaar verschillen. Geconfronteerd met de uitdaging om nieuw multidisciplinair onderzoek & onderwijs rond cyber security te ontwikkelen, ontstond de noodzaak om orde op zaken te stellen en de begrippen helder ten opzichte van elkaar te positioneren. Dit heeft geleid tot een nieuwe conceptualisatie rond de begrippen cyberspace en cyber security. Informatiebeveiliging is in deze visie onderdeel van het bredere begrip van cyber security. De eerste ervaringen rond het gebruik van dit nieuwe begrippenkader zijn zeer positief., Engineering, Systems and Services, Technology, Policy and Management

De termen “informatiebeveiliging” en “cyber security” worden vaak door elkaar gebruikt soms met dezelfde, soms met een afwijkende betekenis. Velen spreken vandaag de dag ook over cyberspace, bijvoorbeeld als een nieuw (door de mens gecreëerd) vijfde domein naast de bestaande domeinen land, water, lucht en ruimte. Een en ander roept de vraag op of informatiebeveiliging en cyber security (wel of niet) fundamenteel van elkaar verschillen. Geconfronteerd met de uitdaging om nieuw multidisciplinair onderzoek & onderwijs rond cyber security te ontwikkelen, ontstond de noodzaak om orde op zaken te stellen en de begrippen helder ten opzichte van elkaar te positioneren. Dit heeft geleid tot een nieuwe conceptualisatie rond de begrippen cyberspace en cyber security. Informatiebeveiliging is in deze visie onderdeel van het bredere begrip van cyber security. De eerste ervaringen rond het gebruik van dit nieuwe begrippenkader zijn zeer positief., Engineering, Systems and Services, Technology, Policy and Management

While supporting regulatory learning processes in work environments is increasingly becoming important, there is not a clear picture of the interaction between self- and coregulatory processes performed by learners in workplace e-learning systems. In this paper, by following a design-based research methodology, we develop a theory-based framework to support the design of an e-learning system aiming at supporting learning regulatory processes in work environments. Then we evaluat the relationship between self- and co-regulatory processes conducted by 177 users in a prototype built upon this framework. The results suggest that there is a significant relationship between self- and co-regulatory learning processes., Engineering, Systems and Services, Technology, Policy and Management

While the concept of Web 2.0 based Personal Learning Environments (PLEs) has generated significant interest in educational settings, there is little consensus regarding what this concept means and how teachers and students can develop and deploy Web 2.0 based PLEs to support their teaching and learning activities. In this paper a conceptual framework for building Web 2.0 based PLEs is proposed. The framework consists of four main elements, including (i) student’s control model, (ii) learning potential of Web 2.0 tools and services, (iii) project-based teaching approach, and (iv) technology-enhanced learning activities. The main purpose of the framework is to assist teachers to design appropriate Web 2.0 based learning activities. Students then can accomplish these learning activities to develop their PLEs and complete their learning projects., Engineering, Systems and Services, Technology, Policy and Management

Urbanism, Architecture and The Built Environment

While supporting regulatory learning processes in work environments is increasingly becoming important, there is not a clear picture of the interaction between self- and coregulatory processes performed by learners in workplace e-learning systems. In this paper, by following a design-based research methodology, we develop a theory-based framework to support the design of an e-learning system aiming at supporting learning regulatory processes in work environments. Then we evaluat the relationship between self- and co-regulatory processes conducted by 177 users in a prototype built upon this framework. The results suggest that there is a significant relationship between self- and co-regulatory learning processes., Engineering, Systems and Services, Technology, Policy and Management

Urbanism, Architecture and The Built Environment

While the concept of Web 2.0 based Personal Learning Environments (PLEs) has generated significant interest in educational settings, there is little consensus regarding what this concept means and how teachers and students can develop and deploy Web 2.0 based PLEs to support their teaching and learning activities. In this paper a conceptual framework for building Web 2.0 based PLEs is proposed. The framework consists of four main elements, including (i) student’s control model, (ii) learning potential of Web 2.0 tools and services, (iii) project-based teaching approach, and (iv) technology-enhanced learning activities. The main purpose of the framework is to assist teachers to design appropriate Web 2.0 based learning activities. Students then can accomplish these learning activities to develop their PLEs and complete their learning projects., Engineering, Systems and Services, Technology, Policy and Management

Implementing personal learning environments (PLEs) in educational settings is a challenging and complex process. Teachers as the main agents of change in their classroom settings need support in designing and implementing these new learning environments and integrating them into the educational process. In this paper, we propose a model to implement Web 2.0 PLEs in educational settings based on the conceived objectives of PLEs, namely (i) enhancing the students’ control in educational process and (ii) supporting and empowering students to build and deploy their PLEs. In addition, we develop a technological prototype based on the model, and report and analyze the perceptions of a group of teachers regarding the potential of the prototype to improve the educational process. The results suggest that the implementation of the model can contribute to the development of a student-centric learning environment and improvement in the teachers’ technological, pedagogical, and content knowledge (TPACK)., Engineering, Systems and Services, Technology, Policy and Management

Building Engineering, Structural Engineering, Civil Engineering and Geosciences

In dit cahier wordt in beknopte vorm verslag gedaan van het onderzoeksproject Integrated Planning and Design in the Delta (IPDD), dat in de periode 2011-2013 is uitgevoerd als onderdeel van het NWO programma Urban Regions in the Delta (URD). Zoals alle URD projecten, is het doel van het IPDD project om kennis te ontwikkelen voor een duurzaam ruimtelijk beleid en voor integrale gebiedsontwikkeling in stedelijke netwerken. De aanleiding hiervan is de transitie waarin ruimtelijk beleid en gebiedsontwikkeling zich bevinden. De sterke cultuur en het institutionele raamwerk van het naoorlogse ruimtelijk beleid, door Faludi en van der Valk als de ‘Dutch planning doctine’ beschreven, en waarmee Nederland internationaal een status als gidsland verwierf, is uitgewerkt. Vooralsnog is niet een vanzelfsprekend alternatief ontstaan., Urbanism, Architecture and The Built Environment

Building Engineering, Structural Engineering, Civil Engineering and Geosciences

Implementing personal learning environments (PLEs) in educational settings is a challenging and complex process. Teachers as the main agents of change in their classroom settings need support in designing and implementing these new learning environments and integrating them into the educational process. In this paper, we propose a model to implement Web 2.0 PLEs in educational settings based on the conceived objectives of PLEs, namely (i) enhancing the students’ control in educational process and (ii) supporting and empowering students to build and deploy their PLEs. In addition, we develop a technological prototype based on the model, and report and analyze the perceptions of a group of teachers regarding the potential of the prototype to improve the educational process. The results suggest that the implementation of the model can contribute to the development of a student-centric learning environment and improvement in the teachers’ technological, pedagogical, and content knowledge (TPACK)., Engineering, Systems and Services, Technology, Policy and Management

In dit cahier wordt in beknopte vorm verslag gedaan van het onderzoeksproject Integrated Planning and Design in the Delta (IPDD), dat in de periode 2011-2013 is uitgevoerd als onderdeel van het NWO programma Urban Regions in the Delta (URD). Zoals alle URD projecten, is het doel van het IPDD project om kennis te ontwikkelen voor een duurzaam ruimtelijk beleid en voor integrale gebiedsontwikkeling in stedelijke netwerken. De aanleiding hiervan is de transitie waarin ruimtelijk beleid en gebiedsontwikkeling zich bevinden. De sterke cultuur en het institutionele raamwerk van het naoorlogse ruimtelijk beleid, door Faludi en van der Valk als de ‘Dutch planning doctine’ beschreven, en waarmee Nederland internationaal een status als gidsland verwierf, is uitgewerkt. Vooralsnog is niet een vanzelfsprekend alternatief ontstaan., Urbanism, Architecture and The Built Environment

The number of inverse infrastructures (Vree, 2003), that is, user-driven and self-organizing infrastructures, is rising and unsettling policies that are foremost tailored to deal with large-scale and centrally-governed infrastructures (Egyedi et al. 2012). To better understand and address this mismatch, Van den Berg (2012) has developed a complex adaptive systems (CAS) framework for analyzing inverse infrastructures. It is based on and well-fits CASs in physics, mathematics and biology. In this paper we explore the framework’s applicability to three inverse infrastructures, i.e.: Wikipedia (Davis and Nikolic, 2012), citizen-driven waste paper collection (De Jong and Mulder, 2012), and the user-driven roll-out of local glass fiber networks (Weijers, 2012; Nederkoorn, 2012). Applying it reveals that, while the framework’s most basic elements can be identified rather straightforwardly, other elements are often more difficult to identify in human CASs. Our tentative conclusion is that (i) the framework is a good starting point for analyzing inverse infrastructures, and (ii) more case studies are needed to fully understand the conditions under which self-organized emergent behavior of complex infrastructures can be observed., Infrastructures, Systems and Services, Technology, Policy and Management

In order to make the international supply chain system highly efficient in worldwide transportation of goods, its business processes should be supported by high quality information systems that, “24x7”, provide the right data, at the right time, at the right place, to the right person. To do so, the idea of a (virtual) “Seamless Integrated Data Pipeline” has been proposed, a new concept of an effective information exchange system. A key requirement of the Data Pipeline is that the information to be exchanged must be safe and reliable. Starting form the idea that existing systems should be used, this paper proposes three basic protocols that enable the secure exchange of data with respect to three identified security requirements, namely, that of secure identification of supply chain partners, that of harmonization of security levels, and that of harmonization of trust levels., Infrastructures, Systems and Services, Technology, Policy and Management

In the current society, logistics is faced with at least two big challenges. The first challenge considers safety and security measurements dealing with terrorism, smuggling, and related security accidents with a high societal impact. The second challenge is to meet sustainability requirements implying optimal use of resources and physical infrastructure. A condition sine qua non for dealing with these challenges is the realization of a flexible platform for sustainable and secure data exchange between collaborating global supply chain actors. This paper presents such a platform. It allows shippers, authorities, logistic service providers, and carriers to be fully interoperable across closed communities, to perform paperless logistics, and to adhere to societal demands of security, safety, and sustainability. Its functionality is derived from similar approaches as have been applied in modern social media. The paper elaborates on the functionality of the platform and its implications for research. It builds upon the research and innovation work as currently done within the EU FP7 Cassandra and iCargo projects., Infrastructures, Systems and Services, Technology, Policy and Management

Although current and upcoming web technologies offer all kinds of new opportunities to support student-centered learning, there does not exist yet a clear roadmap to integrate these technologies into teaching and learning processes. In this paper a model is introduced in order to develop Personal Learning Environements (PLEs) consisting of Web2.0 tools and to integrate them into teaching and learning processes. Next to this, an example implementation in the context of a secondary school is described. Two questions framed this study. First, how do students integrate PLE tools into their learning activities? Second, what is the students and teacher’s perception of the PLE project? Results show, among others, that web2.0 tools should be thoroughly integrated with active teaching and learning methods in order to realize a student-centered learning environment. It was also concluded that students need enough time and teacher’s facilitation in order to get learning and pedagogical value out of PLEs tools and to be able to truly integrate them into their learning activities., Infrastructures, Systems and Services, Technology, Policy and Management

The number of inverse infrastructures (Vree, 2003), that is, user-driven and self-organizing infrastructures, is rising and unsettling policies that are foremost tailored to deal with large-scale and centrally-governed infrastructures (Egyedi et al. 2012). To better understand and address this mismatch, Van den Berg (2012) has developed a complex adaptive systems (CAS) framework for analyzing inverse infrastructures. It is based on and well-fits CASs in physics, mathematics and biology. In this paper we explore the framework’s applicability to three inverse infrastructures, i.e.: Wikipedia (Davis and Nikolic, 2012), citizen-driven waste paper collection (De Jong and Mulder, 2012), and the user-driven roll-out of local glass fiber networks (Weijers, 2012; Nederkoorn, 2012). Applying it reveals that, while the framework’s most basic elements can be identified rather straightforwardly, other elements are often more difficult to identify in human CASs. Our tentative conclusion is that (i) the framework is a good starting point for analyzing inverse infrastructures, and (ii) more case studies are needed to fully understand the conditions under which self-organized emergent behavior of complex infrastructures can be observed., Infrastructures, Systems and Services, Technology, Policy and Management

In order to make the international supply chain system highly efficient in worldwide transportation of goods, its business processes should be supported by high quality information systems that, “24x7”, provide the right data, at the right time, at the right place, to the right person. To do so, the idea of a (virtual) “Seamless Integrated Data Pipeline” has been proposed, a new concept of an effective information exchange system. A key requirement of the Data Pipeline is that the information to be exchanged must be safe and reliable. Starting form the idea that existing systems should be used, this paper proposes three basic protocols that enable the secure exchange of data with respect to three identified security requirements, namely, that of secure identification of supply chain partners, that of harmonization of security levels, and that of harmonization of trust levels., Infrastructures, Systems and Services, Technology, Policy and Management

In the current society, logistics is faced with at least two big challenges. The first challenge considers safety and security measurements dealing with terrorism, smuggling, and related security accidents with a high societal impact. The second challenge is to meet sustainability requirements implying optimal use of resources and physical infrastructure. A condition sine qua non for dealing with these challenges is the realization of a flexible platform for sustainable and secure data exchange between collaborating global supply chain actors. This paper presents such a platform. It allows shippers, authorities, logistic service providers, and carriers to be fully interoperable across closed communities, to perform paperless logistics, and to adhere to societal demands of security, safety, and sustainability. Its functionality is derived from similar approaches as have been applied in modern social media. The paper elaborates on the functionality of the platform and its implications for research. It builds upon the research and innovation work as currently done within the EU FP7 Cassandra and iCargo projects., Infrastructures, Systems and Services, Technology, Policy and Management

Although current and upcoming web technologies offer all kinds of new opportunities to support student-centered learning, there does not exist yet a clear roadmap to integrate these technologies into teaching and learning processes. In this paper a model is introduced in order to develop Personal Learning Environements (PLEs) consisting of Web2.0 tools and to integrate them into teaching and learning processes. Next to this, an example implementation in the context of a secondary school is described. Two questions framed this study. First, how do students integrate PLE tools into their learning activities? Second, what is the students and teacher’s perception of the PLE project? Results show, among others, that web2.0 tools should be thoroughly integrated with active teaching and learning methods in order to realize a student-centered learning environment. It was also concluded that students need enough time and teacher’s facilitation in order to get learning and pedagogical value out of PLEs tools and to be able to truly integrate them into their learning activities., Infrastructures, Systems and Services, Technology, Policy and Management

This paper presents the first bibliometric mapping analysis of the field of computer and information ethics (C&IE). It provides a map of the relations between 400 key terms in the field. This term map can be used to get an overview of concepts and topics in the field and to identify relations between information and communication technology concepts on the one hand and ethical concepts on the other hand. To produce the term map, a data set of over thousand articles published in leading journals and conference proceedings in the C&IE field was constructed. With the help of various computer algorithms, key terms were identified in the titles and abstracts of the articles and co-occurrence frequencies of these key terms were calculated. Based on the co-occurrence frequencies, the term map was constructed. This was done using a computer program called VOSviewer. The term map provides a visual representation of the C&IE field and, more specifically, of the organization of the field around three main concepts, namely privacy, ethics, and the Internet., Infrastructures, Systems and Services, Technology, Policy and Management

This paper presents the first bibliometric mapping analysis of the field of computer and information ethics (C&IE). It provides a map of the relations between 400 key terms in the field. This term map can be used to get an overview of concepts and topics in the field and to identify relations between information and communication technology concepts on the one hand and ethical concepts on the other hand. To produce the term map, a data set of over thousand articles published in leading journals and conference proceedings in the C&IE field was constructed. With the help of various computer algorithms, key terms were identified in the titles and abstracts of the articles and co-occurrence frequencies of these key terms were calculated. Based on the co-occurrence frequencies, the term map was constructed. This was done using a computer program called VOSviewer. The term map provides a visual representation of the C&IE field and, more specifically, of the organization of the field around three main concepts, namely privacy, ethics, and the Internet., Infrastructures, Systems and Services, Technology, Policy and Management

To reveal farmers’ motives for on-farm diversification and integration of farming components in the Mekong Delta, Vietnam, we developed a fuzzy logic model (FLM) using a 10-step approach. Farmers’ decision-making was mimicked in a three-layer hierarchical architecture of fuzzy inference systems, using data of 72 farms. The model includes three variables for family motives of diversification, six variables related to component integration, next to variables for the production factors and for farmers’ appreciation of market prices and know-how on 10 components. To obtain a good classification rate of the less frequent activities, additional individual fine-tuning was necessary after general model calibration. To obtain the desired degree of sensitivity to each variable, it was necessary to use up to five linguistic values for some of the input and output variables in the intermediate hierarchical layers. Model’s sensitivity to motivational variables determining diversification and integration was of the same magnitude as its sensitivity to market prices and farmers’ know-how of the activities, but less than its sensitivity to labour, capital and land endowment. Modelling to support strategic decision-making seems too elaborate for individual farms, but FLM will be useful to integrate farmers’ opinions in strategic decision-making at higher hierarchical levels., Infrastructures, Systems and Services, Technology, Policy and Management

To reveal farmers’ motives for on-farm diversification and integration of farming components in the Mekong Delta, Vietnam, we developed a fuzzy logic model (FLM) using a 10-step approach. Farmers’ decision-making was mimicked in a three-layer hierarchical architecture of fuzzy inference systems, using data of 72 farms. The model includes three variables for family motives of diversification, six variables related to component integration, next to variables for the production factors and for farmers’ appreciation of market prices and know-how on 10 components. To obtain a good classification rate of the less frequent activities, additional individual fine-tuning was necessary after general model calibration. To obtain the desired degree of sensitivity to each variable, it was necessary to use up to five linguistic values for some of the input and output variables in the intermediate hierarchical layers. Model’s sensitivity to motivational variables determining diversification and integration was of the same magnitude as its sensitivity to market prices and farmers’ know-how of the activities, but less than its sensitivity to labour, capital and land endowment. Modelling to support strategic decision-making seems too elaborate for individual farms, but FLM will be useful to integrate farmers’ opinions in strategic decision-making at higher hierarchical levels., Infrastructures, Systems and Services, Technology, Policy and Management

The value of models in process industries becomes apparent in practice and literature where numerous successful applications are reported. Process models are being used for optimal plant design, simulation studies, for off-line and online process optimization. For online optimization applications the computational load is a limiting factor. The focus of this thesis is on nonlinear model approximation techniques aiming at reduction of computational load of a dynamic real-time optimization problem. Two types of model approximation methods were selected from literature and assessed within a dynamic optimization case study: model reduction by projection and physics-based model reduction. Model order reduction by projection is partially successful. Even with a strongly reduced number of transformed differential equations it is possible to compute acceptable approximate solutions. Projection does not provide predictable results in terms of simulation error and stability and does not reduce the computational load of simulation. On the other hand, physics-based model reduction appeared to be very successful in reducing the computational load of the sequential dynamic optimization problem., Design, Engineering and Production

The value of models in process industries becomes apparent in practice and literature where numerous successful applications are reported. Process models are being used for optimal plant design, simulation studies, for off-line and online process optimization. For online optimization applications the computational load is a limiting factor. The focus of this thesis is on nonlinear model approximation techniques aiming at reduction of computational load of a dynamic real-time optimization problem. Two types of model approximation methods were selected from literature and assessed within a dynamic optimization case study: model reduction by projection and physics-based model reduction. Model order reduction by projection is partially successful. Even with a strongly reduced number of transformed differential equations it is possible to compute acceptable approximate solutions. Projection does not provide predictable results in terms of simulation error and stability and does not reduce the computational load of simulation. On the other hand, physics-based model reduction appeared to be very successful in reducing the computational load of the sequential dynamic optimization problem., Design, Engineering and Production

Civil Engineering and Geosciences

Civil Engineering and Geosciences

Electrical Engineering, Mathematics and Computer Science

Recently van den Berg and Kesten have obtained a correlation-like inequality for Bernoulli sequences. This inequality, which goes in the opposite direction of the FKG inequality, states that the probability that two monotone (i.e., increasing or decreasing) events "occur disjointly" is smaller than the product of the individual probabilities. They conjecture that the monotonicity condition is immaterial, i.e., that the inequality holds for all events. In the present paper we try to make clear the intuitive meaning of the conjecture and prove some nontrivial special cases, one of which, a pure correlation inequality, is an extension of Harris' FKG inequality., Electrical Engineering, Mathematics and Computer Science

Electrical Engineering, Mathematics and Computer Science

Recently van den Berg and Kesten have obtained a correlation-like inequality for Bernoulli sequences. This inequality, which goes in the opposite direction of the FKG inequality, states that the probability that two monotone (i.e., increasing or decreasing) events "occur disjointly" is smaller than the product of the individual probabilities. They conjecture that the monotonicity condition is immaterial, i.e., that the inequality holds for all events. In the present paper we try to make clear the intuitive meaning of the conjecture and prove some nontrivial special cases, one of which, a pure correlation inequality, is an extension of Harris' FKG inequality., Electrical Engineering, Mathematics and Computer Science

This graduate thesis is written to finish off my study marine geodesy at the Department of Geodesy, Delft University of Technology. It is based on the calculation of underwater acoustic refraction in a medium with a lineair sound velocity profile. At present most underwater navigation systems are working with underwater sound. The velocity of sound in water is affected by temperature, pressure and salinity. Acoustic rays passing through a medium in which the sound velocity is changing are bent, just like light rays are bent passing between mediums having different propagation velocities. Up to now the curved ray path was computed by a straightforward application of Snellius 's law and geometry. A new method for the reduction of curved acoustic distances is described in this report. These new reduction formulas have been derived for the reduction of electro magnetic waves in the atmosphere by H.Moritz. In this report the Moritz reduction formulas will be applied in combination with the Snellius law on underwater sound rays., Civil Engineering and Geosciences

Document(en) uit de collectie Chemische Procestechnologie, DelftChemTech, Applied Sciences

Document(en) uit de collectie Chemische Procestechnologie, DelftChemTech, Applied Sciences

Civil Engineering and Geosciences