Projekt strukture i analiza čvrstoće palube za slijetanje helikoptera

Paluba ili platforma za slijetanje helikoptera je za većinu trgovačkih, putničkih i posebice specijalnih tipova brodova (offshore, istraživački) od velike važnosti, kako za komunikaciju tako i za moguće hitne situacije. Navedeno naročito dolazi do izražaj kod brodova koji se bave složenim offshore operacijama u teškim vremenskim prilikama i stanjima mora. Uvodno su prikazane vrste i pregled projektnih parametara platforme za slijetanje helikoptera. Za odabrani tip istraživačkog broda napravljen je projekt strukture, računalni model i analiza čvrstoće. Korištena su pravila i propisi klasifikacijskog društva American Bureau of Shipping za određivanje minimalnih strukturnih dimenzija, kao i za definiranje projektnih stanja opterećenja, te konačno kriterija za potvrdu projekta. Za izradu računalnog modela i analizu strukture metodom konačnih elemenata korišten je 3D CAD programski paket Inventor. Definirani su najgori slučajevi opterećenja, te su na osnovi izvršene analize usvojene konačne dimenzije strukture

Optimal VDC service provisioning in optically interconnected disaggregated data centers

©2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Virtual data center (VDC) is a key service in modern data center (DC) infrastructures. However, the rigid architecture of traditional servers inside DCs may lead to blocking situations when deploying VDC instances. To overcome this problem, the disaggregated DC paradigm is introduced. In this letter, we present an integer linear programming (ILP) formulation to optimally allocate VDC requests on top of an optically interconnected disaggregated DC infrastructure, aiming to quantify the benefits that such an architecture can bring when compared with traditional server-centric DCs. Moreover, a lightweight simulated annealing-based heuristic is provided for the scenarios where the ILP scalability is challenged. The obtained numerical results reveal the substantial benefits yielded by the resource disaggregation paradigm.Peer ReviewedPostprint (author's final draft

End-to-end 5G service deployment and orchestration in optical networks with QoE guarantees

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThe upcoming 5G deployments will impose stringent requirements. Optical networks control and resource orchestration is set to potentially turn into software-defined approaches in order to address such requirements. As a result, there rises a need for an architectural scheme capable of supporting the different types of services defined for 5G verticals.We present in this paper an architecture enabling end-to-end (E2E) provisioning and monitoring of such 5G services over optical network segments. In particular, the scenario considers the coordination of various optical enabled network segments by a higher level E2E Orchestrator, which provides of network slice deployment and is able to guarantee agreed levels of Quality of Experience (QoE). Moreover, we discuss an example of 5G service provisioning using the proposed architecture to demonstrate its behaviour in front of different network events.Peer ReviewedPostprint (author's final draft

ASTEC V1.3 Code Assessment on the STORM Aerosols Mechanical REsuspension Test (A Fission Product Transport Study)

The European severe accident analysis code ASTEC is assessed on the most representative STORM tests. Two aerosol resuspension modules are used to calculate the resuspended fraction of aerosols deposited in the primary circuit model of STORM facility. It was concluded thta concerning the final mass fraction and mainly the kinetics of aerosol resuspension in turbulent pipe flow conditions there is a need for further code assesment and for improvement of resuspension models implemented in the current version of SOP"HAEROS/ASTEC V1.3 code. This is under way in the Source Term area of the SARNET project.JRC.F.4-Nuclear design safet

On the complexity of configuration and orchestration for enabling disaggregated server provisioning in optical composable data centers

Due to the limitations of traditional data center (DC) architectures, the concept of infrastructure disaggregation has been proposed. DC resources are separated into multiple blades to be exploited independently. As a result, composable DC (CDC) infrastructures are achieved, enhancing the modularity of resource provisioning. However, disaggregation introduces additional challenges that need to be carefully analyzed. One relates to the potential complexity increase on the orchestration and infrastructure configuration that need to be performed when provisioning resources to support services. This aspect is highly influenced by the distribution of resources at the physical infrastructure. As such, when analyzing the performance of a CDC, it becomes essential to also study the related operational complexity of the resource orchestration and configuration phases. Furthermore, the requirements of several tenant services may impose heterogeneous deployments over the shared physical infrastructure in the form of either disaggregated single-server or multi-server distributions. The associated orchestration/configuration cost is again highly influenced by the data plane architecture of the CDC. With these aspects in mind, in this paper, we provide a methodology for analysis of the complexity of resource orchestration for a service deployment and the associated configuration cost in optical CDCs, considering various service deployment setups. A selected set of CDC architectures found in the literature is employed to quantitatively illustrate how the data plane design and service deployment strategies affect the complexity of infrastructure configuration and resource orchestration.This work has been supported by the Spanish Government through project TRAINER-B (PID2020-118011GB-C22) with FEDER contribution.Peer ReviewedPostprint (author's final draft

Dynamic service reallocation in NFV-based transport WDM optical networks

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Future network services are expected to deliver additional functionalities besides connectivity. The Network Function Virtualization (NFV) paradigm provides the foundation for such concept. We propose a reallocation-based provisioning mechanism to enrich service provisioning architectures in NFV-based transport optical networks, achieving up to three orders of magnitude reductions in experienced blocking.Peer ReviewedPostprint (published version

Supporting QoE/QoS-aware end-to-end network slicing in future 5G-enabled optical networks

Copyright 2019 Society of Photo‑Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this publication for a fee or for commercial purposes, and modification of the contents of the publication are prohibited.Network slicing with Quality of Experience/Quality of Service (QoE/QoS) guarantees is seen as one of the key enablers of future 5G networks. Nevertheless, it poses several challenges in both resource provisioning and management that need to be addressed for the efficient end-to-end service delivery. In particular, network slice deployments considering operation across several domains and network segments, require of inter-domain configurations, continuous monitoring, potential actuations, inter-slice isolation, among other, in order to be provisioned and maintained, looking forward to guaranteeing their assured Key Performance Indicators (KPIs). In such scenario, optical networks are of prime importance, enabling the inter-connectivity between multiple far away segments and Points of Presence (PoPs). In light of this, in this paper we present an architecture design enabling network slice provisioning for 5G service chaining in multi-segment/multi-domain optical network scenarios. The presented design is enriched with a policy-based monitoring and actuation framework able to maintain the desired QoS for the provisioned end-to-end (E2E) network slice. We experimentally validated the proposal against real slice deployments and traffic generation, providing a proof of concept for the presented architecture, with special emphasis in the demonstration of the actuation framework as a key element for quality guarantees.Peer ReviewedPostprint (published version

Enabling multi-segment 5G service provisioning and maintenance through network slicing

This is a post-peer-review, pre-copyedit version of an article published in Journal of Network and Systems Management . The final authenticated version is available online at: http://dx.doi.org/10.1007/s10922-019-09509-9The current deployment of 5G networks in a way to support the highly demanding service types defined for 5G, has brought the need for using new techniques to accommodate legacy networks to such requirements. Network Slicing in turn, enables sharing the same underlying physical infrastructure among services with different requirements, thus providing a level of isolation between them to guarantee their proper functionality. In this work, we analyse from an architectural point of view, the required coordination for the provisioning of 5G services over multiple network segments/domains by means of network slicing, considering as well the use of sensors and actuators to maintain slices performance during its lifetime. We set up an experimental multi-segment testbed to demonstrate end-to-end service provisioning and its guarantee in terms of specific QoS parameters, such as latency, throughput and Virtual Network Function (VNF) CPU/RAM consumption. The results provided, demonstrate the workflow between different network components to coordinate the deployment of slices, besides providing a set of examples for slice maintenance through service monitoring and the use of policy-based actuations.Peer ReviewedPostprint (author's final draft

Orchestrated SDN-based VDC provisioning over multi-technology optical data centre networks

©2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In this paper, we describe some scenarios and technologies that have been proposed to cope with the requirements of current and next generation data centre infrastructure. In particular, we discuss the extensions that have been implemented at both orchestration and control levels to efficiently manage the data centres resources. We put the focus on the integration between the Orchestrator and the SDN Controller by describing the communication interfaces and their interaction to provision optimized Virtual Data Centres (VDC) instances over novel data centre infrastructure, with special mention to the different solutions adopted to manage multiple optical technologies at the data plane.Peer ReviewedPostprint (author's final draft

SDN-based parallel link discovery in optical transport networks

This is the peer reviewed version of the following article: Montero R, Agraz F, Pagès A, Perelló J, Spadaro S. SDN‐based parallel link discovery in optical transport networks. Trans Emerging Tel Tech. 2018;e3512. https://doi-org.recursos.biblioteca.upc.edu/10.1002/ett.3512, which has been published in final form at https://doi-org.recursos.biblioteca.upc.edu/10.1002/ett.3512. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.The use of optical technologies in modern network scenarios has increased in the last decade, mostly due to their support in crucial networking topics (ie, bandwidth and scalability). In parallel, these scenarios have also experienced the emergence of a new paradigm recognized as software-defined networking (SDN), which bases on the decoupling of forwarding and control functions, with aims to provide a more efficient way to manage network resources compared to legacy networking architectures. As both SDN and optical technologies are constantly being introduced in different networking scenarios (eg, data centers, metro, and access networks), their coexistence becomes a must. In this matter, it is important to notice that SDN was initially designed for electronic-based networks; hence, its support for optical technologies is still at an early stage. Consequently, integration of both solutions still requires research efforts by the community. In this paper, we present a mechanism to address topology discovery in wavelength-switching optical transport networks (OTNs). In particular, we discuss the importance of the topology discovery function and analyse the proposed mechanism, which bases itself on the use of wavelength-specific signaling tones as link-binding data to provide preservice parallel link discovery in OTNs. Furthermore, we validate the method experimentally against an emulated OTN testbed with two different setups and compare the results to our previous work on this subject, achieving substantial reductions in the total topology discovery time.Peer ReviewedPostprint (author's final draft