Rui António dos Santos Cruz
@ulisboa.pt
Instituto Superior Técnico, Universidade de Lisboa
Scopus Publications
Scopus Publications
Pedro Maximino, Rui S. Cruz, Miguel L. Pardal
Iberian Conference on Information Systems and Technologies Cisti, 2023
In an age where citizens are constantly moving between different places, transport demand is extremely high, and so, it is important to have sophisticated public transportation systems in place to ensure a sustainable development of urban areas and meet the needs of citizens. Public transport operators consequently need to provide reliable services in order to minimize disruption events that can affect the vehicles and their drivers, such as breakdowns, accidents or illnesses. The project here described focuses on the type of events and approaches related with the vehicle drivers and the identification of both their performance profiles and health condition while in operation. For that purpose, existing nonintrusive technologies present on the vehicle are leveraged, able to collect data related to physiological measurements taken in realtime. Such sensitive data will be processed, stored and shared in a secure manner, using blockchain-based technologies, so that only authenticated and authorized parties will be able to access the data, according to their clearance level, through an Application Programming Interface (API) designed for that purpose. The architecture of the system will be microservices-based, with components deployed at different infrastructure levels—from On Board Units (OBUs) in vehicles up to cloud-based subsystems.
Miguel Moreira Oliveira, Rui Santos Cruz
Iberian Conference on Information Systems and Technologies Cisti, 2022
Manuel Duarte Mascarenhas, Rui Santos Cruz
Iberian Conference on Information Systems and Technologies Cisti, 2022
Sara Rouhani, Rafael Belchior, Rui S. Cruz, Ralph Deters
World Wide Web, 2021
Auditing provides an essential security control in computer systems, by keeping track of all access attempts, including both legitimate and illegal access attempts. This phase can be useful to the context of audits, where eventual misbehaving parties can be held accountable. Blockchain technology can provide trusted auditability required for access control systems. In this paper, we propose a distributed \\ac{ABAC} system based on blockchain to provide trusted auditing of access attempts. Besides auditability, our system presents a level of transparency that both access requestors and resource owners can benefit from it. We present a system architecture with an implementation based on Hyperledger Fabric, achieving high efficiency and low computational overhead. The proposed solution is validated through a use case of independent digital libraries. Detailed performance analysis of our implementation is presented, taking into account different consensus mechanisms and databases. The experimental evaluation shows that our presented system can process 5,000 access control requests with the send rate of 200 per second and a latency of 0.3 seconds.
Mariana Cruz, Rui S. Cruz
Iberian Conference on Information Systems and Technologies Cisti, 2021
Railway networking systems are critical infrastructures that must support fast, reliable and low delay communications. Technologies still used in those infrastructures---such as GSM-R, evolving into LTE-R are becoming more complex, yet more flexible, and evolving to "software defined" architectures. The technologies presented and explored in this work are expected to change the future of these types of critical systems. The main goal of this work is to study the key benefits of using the SDN model to control the next generation railways networking infrastructures. The safety, security and correctness properties of SDN controllers in high availability railway networks will be analyzed, for compliance with the European Rail Traffic Management System (ERTMS)/European Train Control System (ETCS) specifications, and in the context of a real project being deployed in a Portuguese Railway by Thales Portugal. From the analysis of the project requirements and the selected network equipment, it was possible to evaluate and propose adequate methods to automatically derive network re-configuration strategies, namely in case of failure events---e.g., preventing packet loss affecting vital railway traffic signaling procedures---in order to reduce field intervention and complexity in those infrastructures.
Miguel Oliveira, Rui S. Cruz
Iberian Conference on Information Systems and Technologies Cisti, 2021
To support new and more complex software systems, tools, and applications, the IT Infrastructures have evolved to be more flexible and grow both in size and complexity. To manage those Infrastructures, several tools are used. For large datacenters and public cloud infrastructures, complex managements systems have been developed in-house, according to specific implementations and philosophies. However, for the small, business owned, infrastructures, such tools are usually used independently. In this paper, we present the architecture of a new Orchestrator tool that aims to provide a single point of management, while also maintaining a resource inventory, by means of a Distributed Ledger, in order to maintain records of all the changes in the infrastructure, ensuring traceability over past changes, and even allowing for rollback of certain actions.
Carolina Fernandes, Rui Cruz
Journal of Information Systems Engineering and Management, 2021
The problem between Over-the-Top (OTT) and Communications Service Provider (CSP), namely for multimedia streaming services, is not new and has been a topic much discussed in the TM Forum. At time of writing, a technical solution that would benefit both parties has not yet been presented. With the existing model (no operational integration), both OTTs and CSPs are dissatisfied. This paper proposes a technical solution that can be beneficial to both parties and can potentially solve the existing conflicts. The solution presents the high-level design of Business Processes to integrate OTT Service Platforms in CSP Operations. Some hypothetical, but close to reality scenarios were defined in order to show how the model could be applied. The design of the model incorporates information and suggestions collected from Portuguese CSPs. To evaluate the accuracy of the design methodology, a set of interviews were conducted with industry experts in the sector, who evaluated each process model of the solution. A set of surveys from end users of those types of services was also conducted, in order to understand their opinions about the ideas used for the construction of the model.
Carolina Fernandes, Rui Cruz
Iberian Conference on Information Systems and Technologies Cisti, 2020
The problem between Over-the-Top (OTT) and Communications Service Provider (CSP), namely for multimedia streaming services, is not new and has been a topic much discussed in the TM Forum. At time of writing, a technical solution that would benefit both parties has not yet been presented. With the existing model (no operational integration), both OTTs and CSPs are dissatisfied. This paper proposes a technical solution that can be beneficial to both parties and can potentially solve the existing conflicts. The solution presents the high-level design of Business Processes to integrate the OTT Service Platforms in CSP Operations. Some hypothetical, but close to reality scenarios were defined in order to show how the model could be applied. The design of the models incorporates information and suggestions collected from Portuguese CSPs. To evaluate the accuracy of the methodology, a set of interviews were conducted with industry experts, who evaluated each model of the solution. A set of surveys from users of these types of services was also conducted, in order to understand their opinions about the ideas used in the construction of the model.
Antonio Calcada, Rui Cruz
Iberian Conference on Information Systems and Technologies Cisti, 2020
Aging demographic, intermittent treatment and increasing costs of care characterise the situation the Healthcare sector is facing. Further, the increase in access and use of more sophisticated, cheaper and wearable technologies, sets the opportunity for the development of novel Healthcare related solutions that can bring a positive and transformative change in the Healthcare landscape. This work presents the development of an alarm algorithm and respective monitoring strategy for an outpatient scenario employing wearable technology. The research methodology that was followed allowed to identify and determine the Vital Body Signs (VBSs) and thresholds characterising medical conditions and deviations from the normal physiological state. A survey conducted among Healthcare experts, provided the validation, with agreement rates over 71%, of the set of VBSs and respective thresholds to integrate in the alarm algorithm in order to enable the detection of both life-threatening and increased Health risk situations. The validation tests performed through the analysis of Health Data sets, enabled the design of the proposed model, and also to identify its limitations.
Rui S. Cruz, Miguel Casquilho
Iberian Conference on Information Systems and Technologies Cisti, 2019
This study is based on a concrete problem in a fertilizer factory about the estimation of process parameters: to calculate the mean and standard deviation from weights (sums only)of loads of unequal (known)number of bags (“equal” case being trivial). With many distribution depots., the data for each depot must be collected for processing. These are addressed in a Cloud Computing., big-data framework. The use of Apache Spark is described and adopted., as advantageous over Hadoop due to “in-memory computation” and Resilient Distributed Dataset. The computation uses Terraform and Ansible as configuration tool, and is deployed on the Google Cloud Platform. The evaluation preliminary tests confirmed good accuracy and produced low runtimes.
Rui Cruz, Joao Jardim, Joao Mira, Carlos Teixeira
Proceedings of 2018 16th International Conference on Intelligent Transport System Telecommunications Itst 2018, 2018
Rui Santos Cruz, Mário Serafim Nunes
Peer to Peer Networking and Applications, 2015
Jânio M. Monteiro, Rui S. Cruz, Charalampos Z. Patrikakis, Nikolaos C. Papaoulakis, Carlos T. Calafate, et al.
Digital Arts and Entertainment Concepts Methodologies Tools and Applications, 2014
António Pedro Inácio, Rui Santos Cruz, Mário Serafim Nunes
Annales Des Telecommunications Annals of Telecommunications, 2013
Mikoaj Leszczuk, Rui Cruz, Dawid Juszka, Mario Nunes, Lucjan Janowski, et al.
2013 IEEE Globecom Workshops GC Wkshps 2013, 2013
Jânio M. Monteiro, Rui S. Cruz, Charalampos Z. Patrikakis, Nikolaos C. Papaoulakis, Carlos Tavares Calafate, et al.
Multimedia Networking and Coding, 2012
Joana Palhais, Rui S. Cruz, Mário S. Nunes
Lecture Notes of the Institute for Computer Sciences Social Informatics and Telecommunications Engineering, 2012
Charalampos Patrikakis, Nikolaos Papaoulakis, Panagiotis Papageorgiou, Aristodemos Pnevmatikakis, Paul Chippendale, et al.
IEEE Multimedia, 2011
Rui A. Santos Cruz, Mário Serafim Nunes, Leandro Menezes, João Domingues
Multimedia Tools and Applications, 2011
Hugo Santos, Rui Santos Cruz, Mário Serafim Nunes
Lecture Notes of the Institute for Computer Sciences Social Informatics and Telecommunications Engineering, 2010
Rui Santos Cruz, Mário Serafim Nunes, João Espadanal Gonçalves
Lecture Notes of the Institute for Computer Sciences Social Informatics and Telecommunications Engineering, 2010
Winsys 2010 Proceedings of the International Conference on Wireless Information Networks and Systems, 2010
Joao Espadanal Goncalves, Rui Santos Cruz, Mario Serafim Nunes
6th Euro Nf Conference on Next Generation Internet Ngi 2010 Proceedings, 2010
Rui Santos Cruz, Mario Serafim Nunes, Charalampos Z. Patrikakis, Nikolaos C. Papaoulakis
2010 IEEE Globecom Workshops GC 10, 2010
2009 10th International Conference on Telecommunications Contel 2009, 2009