2022 32nd International Telecommunication Networks and Applications Conference (ITNAC)

Producción CientíficaMulti-band elastic optical network (MB-EON) is a promising technology to extend the bandwidth of the current elastic optical networks in the middle term. The migration from current networks to MB-EONs should be made carefully taking into account both the required cost and the bandwidth requirements. This paper focuses on the necessity of looking for a trade-off between the links to be upgraded during the migration from the standard C-band to the L-band and the acceptable level of capacity increase. Therefore, it makes two contributions to efficiently upgrade current elastic optical networks: firstly, a planning method to decide which fibers should be upgraded to exploit C+L band; and second, one heuristic for solving the routing, band, modulation level, and spectrum assignment (RBMLSA) problem during network operation. Simulation results demonstrate that, thanks to use of these proposals, the upgrade of a set of the fibers could be viewed as a fully convincing middle term solution by the network operators to get around the huge cost of the whole network migration to C+L line system.EU H2020 MSCA ITN-ETN IoTalentum (grant no. 953442);Ministerio de Ciencia e Innovación y Agencia Estatal de Investigación (Proyecto PID2020-112675RB-C42 financiado por MCIN/AEI/10.13039/501100011033)EU H2020 B5G-OPEN (GA 101016663

A new empirical model to predict stress intensity factor for double interacting surface cracks located in hollow cylinder

Fracture in cylinders is one of the most popular types of failure. Owing to the impact of production processes, nondestructive testing, and severe operational conditions, etc., cracks exist. The cracks could be detected in single or multiple form, where multiple cracks considered among the significant concerns that cylinders expected to experience. This is because in the existence of multiple neighboring cracks, crack interaction can take place between cracks and accelerates fracture process and lead to a catastrophic failure. Consequently, this study focuses on the problem of double interacting surface cracks located on external and internal surfaces of a hollow cylinder and oriented into parallel and non-coplanar parallel cracks configuration. Stress Intensity Factor (SIFs) has been chosen as the driving force to define the crack interaction. The SIFs have been analyzed for a wide variety of crack geometry, and cylinder type as well as separation distances utilizing finite element software Ansys under different types of mechanical loadings. Based on the analysis results, an empirical mathematical model was produced to predict the SIFs for double parallel cracks using the SIFs for a single crack, for thick and thin cylinders, separately. The empirical model was verified in terms of performance evaluation metrics, which exhibited prediction error less than 5%. Also, it is shown that crack interaction influence for parallel cracks demonstrated by shielding interaction influence only, while both shielding, and amplification impacts produced for non-coplanar cracks. The crack separation distance (horizontal and angular) between the cracks displayed substantial influence on interaction since it exhibited the ability to convert the interaction behavior from shielding to amplification impact (for angular). The presented results in this research serve the literature database since SIFs for a wide variety of cracks geometry have been introduced under different types of loading. Besides, the proposed mathematical model could be used easily and confidently as it displayed a high rate of accuracy

No. 11: The State of Food Insecurity in Cape Town

Cape Town is one of the wealthiest cities in the Southern African region. Yet, the vast majority of households in poor areas of the city experience food insecurity. This paper uses AFSUN data to examine the characteristics and drivers of food insecurity in Cape Town. While food insecurity correlates closely with income poverty and household structure, broader factors also impact upon urban food security, most notably urban design and market structure. Efforts to address urban food insecurity should therefore not simply target the household. Instead, a food systems approach is necessary, which considers supply chains, procurement, nutrition support programmes, public health, environmental sustainability, water and waste, the support of local enterprise and so on. Furthermore, this approach must consider the geography of the urban food system, in particular planning and zoning regulations regarding the location of both formal and informal food retail within low-income areas of the city