411 research outputs found
Safety-oriented Testing for High-speed Rail Onboard Equipment Using Petri Nets
With its ability to operate at high speeds and capacity, high-speed rail offers a fast, dependable, and ecofriendly urban transportation option. Safety-critical systems such as high-speed rail signaling systems must be tested regularly to assess compliance with specifications and ensure reliable performance. Given that the onboard equipment is the core component of the signaling system, conducting safety testing on this equipment is of utmost importance. Current methods of analyzing test requirements mainly rely on human interpretation of specifications. However, the official technical specifications usually only outline standard operational scenarios, which could result in an inefficient and unclear safety analysis. This paper focuses on safety-oriented testing for onboard equipment. In particular, we propose a Petri net based approach to generate test cases for diverse operational scenarios. This approach improves both the efficiency and reliability of the testing process while ensuring compliance with safety requirements
Natural vs. Anthropic influence on the multidecadal shoreline changes of mediterranean urban beaches: Lessons from the Gulf of Cagliari (Sardinia)
Urban Mediterranean beaches are often characterized by a fragile and unstable equilibrium that can be easily altered by ongoing climate change and by the increase in human pressure. This may pose serious threats to the survival of beach systems that cannot accommodate these modifications. In this paper, the spatio-temporal shift of the shoreline was investigated along two urban beaches in the Gulf of Cagliari (Poetto and Giorgino; southern Sardinia, western Mediterranean Sea) across a time frame of 62 years (1954–2016). The Digital Shoreline Analysis System (DSAS) ArcGIS™ extension was used to extract different statistical parameters which allowed us to quantify the erosion and accretion rates. These data were further examined in relation to a number of anthropic and natural forcings in order to disentangle the factors controlling shoreline evolution. Eight sectors with interchanging net erosive and accretion trends were identified along the Poetto and Giorgino beaches. In six decades, some sectors of the two study sites appeared to have undergone great shoreline modification as a result of the intense anthropogenic activities impacting these coastal areas. The westernmost portions of both beaches were found to be the most vulnerable to erosion processes; such conditions were likely controlled by the interplaying of local hydrodynamics and by the intense coastal development which affected these sectors. The highest retreat rates (mean end point rate (EPR) = −0.51/year) were recorded in the western limit of Giorgino beach. Along the western limit of Poetto beach, EPR erosion rates (mean EPR = −2.92/year) considerably increased in the years after the artificial beach nourishment carried out in 2002, suggesting that the majority of the nourished material was lost offshore or partly redistributed along the beach. Coastal structures, urban development, river catchment modification, industrial and port activities, beach cleaning and touristic and recreational activities have been identified as the ongoing causes of coastal alteration. If these factors remain constant, under projected climate change scenarios, these beaches are at risk of further increased flooding and erosion. In this context, the application of DSAS appeared as an essential tool, supporting a monitoring system able to provide understanding and, potentially, predictions of the short-to long-term evolution of these beach systems
PMC21 PATIENT-REPORTED OUTCOMES IN PRODUCT DEVELOPMENT GUIDANCE
Medina Campeny, XavierHomenatge a Mercè Rodoreda amb una reproducció del personatge de la Colometa, a la Plaça del Diamant, novel·la de l'escriptora. Al 1984 es va posar provisionalment a la pl. Rius i Taulet. Al 1990 es va traslladar a l'actual emplaçament
Characterizing Sulfolobus spindle shaped viruses from Yellowstone National Park and Kamchatka, Russiaerizing
Viruses are important drivers of evolution for organisms across the three domains of life. We study how microbes co-evolve with their viruses using the model thermoacidophilic archaea Sulfolobus islandicus, which is found in hot springs around the world and is commonly infected by Sulfolobus spindle-shaped viruses (SSVs). SSV9, from Kamchatka, Russia, exhibits a unique phenotype that causes non-infected S. islandicus cells to go dormant and die while infected cells survive. To explore if this phenotype is broadly functional, we tested the effect of SSV9 on multiple S. islandicus strains and Sulfolobus species. We also investigated whether other SSVs from Kamchatka or Yellowstone National Park possess the ability to inhibit the growth of non-infected cells. The results from these experiments inform us of how broadly applicable the killing of non-infected cells is among SSVs and provide an improved understanding of the ways that viruses affect the evolution of their microbial hosts.Ope
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