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

Lehman Brothers Letter to the SEC

This letter is addressed to Jonathan G. Kat

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

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

Examining Neanderthal and carnivore occupations of Teixoneres Cave (Moià, Barcelona, Spain) using archaeostratigraphic and intra-site spatial analysis

Teixoneres Cave (Moia, Barcelona, Spain) is a reference site for Middle Palaeolithic studies of the Iberian Peninsula. The cave preserves an extensive stratigraphic sequence made up of eight units, which is presented in depth in this work. The main goal of this study is to undertake an initial spatial examination of Unit III, formed during Marine Isotope Stage 3, with the aim of understanding spatial organization and past activities developed by Neanderthals and carnivores (bears, hyenas and smaller carnivores). The total sample analysed includes 38,244 archaeological items and 5888 limestone blocks. The application of GIS tools allows us to clearly distinguish three geologically-defined stratigraphic subunits. Unit III has been previously interpreted as a palimpsest resulting from alternating occupation of the cave by human groups and carnivores. The distribution study shows that faunal specimens, lithic artefacts, hearths and charcoal fragments are significantly concentrated at the entrance of the cave where, it is inferred, hominins carried out different activities, while carnivores preferred the sheltered zones in the inner areas of the cave. The results obtained reveal a spatial pattern characterized by fire use related zones, and show that the site was occupied by Neanderthals in a similar and consistent way throughout the (>)7000 years range covered by the analysed subunits. This spatial pattern is interpreted as resulting from repeated short-term human occupations

Low‐cost technologies in a rich ecological context: Hotel California open‐air site at Sierra de Atapuerca, Burgos, Spain

OnlinePublHotel California is part of a network of open‐air Neanderthal sites located in the Sierra de Atapuerca (Burgos, Spain). In this study, we examine the technology of the lithic assemblages recovered from this site's archaeological levels 3 to 7, which are characterised by the use of local raw materials, non‐hierarchical centripetal exploitation systems, systematic production of flakes and few retouched items. This type of expedient technology is repeated throughout the entire sequence, which spans Marine Isotope Stages (MIS) 3 to 4. Through a comparison with the technocomplexes and occupation histories of surrounding sites – including a re‐evaluation of the published chronology for the nearby site of Fuente Mudarra, which is now dated exclusively to MIS 5 – we examine whether the detected pattern is applicable to the rest of the Atapuerca Mousterian record and if this expedient behaviour has equivalents in other sites in the region. Our findings show that the lithic procurement, exploitation and configuration strategies employed at the Sierra de Atapuerca open‐air sites were constant over broad time periods spanning MIS 5 to 3, in contrast to the technological sequences observed at other nearby sites on the Northern Iberian Plateau. The recurrent settlement of these open‐air Neanderthal sites over tens of thousands of years and the consistent use of expedient technologies during different occupation periods is likely attributable to the rich ecological context of the Sierra de Atapuerca environs.Marta Santamaría, Marta Navazo, Lee J. Arnold, Alfonso Benito-Calvo, Martina Demuro, and Eudald Carbonel