1,350 research outputs found
Safety and Security Analysis of AEB for L4 Autonomous Vehicle Using STPA
Autonomous vehicles (AVs) are coming to our streets. Due to the presence of highly complex software systems in AVs, there is a need for a new hazard analysis technique to meet stringent safety standards. System Theoretic Process Analysis (STPA), based on Systems Theoretic Accident Modeling and Processes (STAMP), is a powerful tool that can identify, define, analyze and mitigate hazards from the earliest conceptual stage deployment to the operation of a system. Applying STPA to autonomous vehicles demonstrates STPA\u27s applicability to preliminary hazard analysis, alternative available, developmental tests, organizational design, and functional design of each unique safety operation.
This paper describes the STPA process used to generate system design requirements for an Autonomous Emergency Braking (AEB) system using a top-down analysis approach to system safety. The paper makes the following contributions to practicing STPA for safety and security:
1) It describes the incorporation of safety and security analysis in one process and discusses the benefits of this;
2) It provides an improved, structural approach for scenario analysis, concentrating on safety and security;
3) It demonstrates the utility of STPA for gap analysis of existing designs in the automotive domain;
4) It provides lessons learned throughout the process of applying STPA and STPA-Sec
Morphology with Light Profile Fitting of Confirmed Cluster Galaxies at z=0.84
We perform a morphological study of 124 spectroscopically confirmed cluster
galaxies in the z=0.84 galaxy cluster RX J0152.7-1357. Our classification
scheme includes color information, visual morphology, and 1-component and
2-component light profile fitting derived from Hubble Space Telescope riz
imaging. We adopt a modified version of a detailed classification scheme
previously used in studies of field galaxies and found to be correlated with
kinematic features of those galaxies. We compare our cluster galaxy
morphologies to those of field galaxies at similar redshift. We also compare
galaxy morphologies in regions of the cluster with different dark-matter
density as determined by weak-lensing maps. We find an early-type fraction for
the cluster population as a whole of 47%, about 2.8 times higher than the
field, and similar to the dynamically young cluster MS 1054 at similar
redshift. We find the most drastic change in morphology distribution between
the low and intermediate dark matter density regions within the cluster, with
the early type fraction doubling and the peculiar fraction dropping by nearly
half. The peculiar fraction drops more drastically than the spiral fraction
going from the outskirts to the intermediate-density regions. This suggests
that many galaxies falling into clusters at z~0.8 may evolve directly from
peculiar, merging, and compact systems into early-type galaxies, without having
the chance to first evolve into a regular spiral galaxy.Comment: 13 pages, 11 figures, accepted for publication in A&
Ex-vivo perfusion bioassay : an excellent technique to measure the bioactivity of inhalable insulin coated microcrystals
Purpose: To measure the bioactivity of inhalable insulin coated microcrystals using a perfusion bioassay that measures its vasodilatory effect on smooth muscle arterial tissue. Methods: The bioactivity of an insulin protein coated microcrystal (PCMC), a potential candidate for pulmonary drug delivery and commercial insulin was determined on a Danish Myo Tech P110 pressure myograph system. 12 week old Mesenteric resistance arteries from Male Wistar rats were isolated and immersed in a physiological salt solution (PSS) and attached to 2 opposing hollow glass micro-cannula (outer diameter 80 microns). The PSS was gradually warmed to 37°C (at a pressure less than 5mm Hg) for 1hr. Subsequently the pressure was increased up to 40mm Hg over a period 15 minutes and equilibrated for a further 15 minutes after gassing with 95%O2 / 5%CO2 to achieve a pH of 7.4 at 37°C. After normalisation by two washes of 123mM KCl and exposure to 1-10mM noradrenaline the arteries were exposed intraluminally to each insulin preparation by gradual infusion directly into the lumen via a fetal microcannulae inserted to the tip of the glass mounting cannula, at a constant pressure. Results: The preliminary results (full cummulative response curve yet to be determined) demonstrate insulin mediated relaxation to noradrenaline preconstriction. The level of constriction drops from 100% to 42% as the concentration of insulin increases from -11 to -9 Log M for the PCMC compared with a drop from 100 % to 65% for the commercial insulin preparation. However the more potent vasodilatory effect found for the insulin PCMC is more likely to be a result of variance introduced in each dilution step than a real increase in potency. Conclusion: The perfusion bioassay technique provides an excellent method of measuring insulin bioactivity and indicates the insulin loaded on the microcrystal support is fully active
Accurate Sky Continuum Subtraction with Fibre-fed Spectrographs
Fibre-fed spectrographs now have throughputs equivalent to slit
spectrographs. However, the sky subtraction accuracy that can be reached has
often been pinpointed as one of the major issues associated with the use of
fibres. Using technical time observations with FLAMES-GIRAFFE, two observing
techniques, namely dual staring and cross beam-switching, were tested and the
resulting sky subtraction accuracy reached in both cases was quantified.
Results indicate that an accuracy of 0.6% on sky subtraction can be reached,
provided that the cross beam-switching mode is used. This is very encouraging
with regard to the detection of very faint sources with future fibre-fed
spectrographs, such as VLT/MOONS or E-ELT/MOSAIC.Comment: to appear in ESO Messenger, March 201
Diseño y automatización de una máquina de corte cartesiano para mayólicas en el proceso de enchapado en pisos de edificios residenciales
El presente trabajo muestra la realización del diseño y automatización de una máquina de corte cartesiano para mayólicas en el proceso de enchapado en pisos de edificios residenciales, con la finalidad de disminuir el tiempo que tarda el proceso, ya que actualmente los operarios lo realizan de manera empírica, ocurriendo errores de cálculos lo que conlleva a gastos de recursos innecesarios. El diseño se lleva a cabo empleando.
“Design methodology for mechatronics systems” VERIN DEUTSCHER INGENIEURE (VDI 2206) (VDI 2206, 2003), este método optimiza cada etapa con criterios de evaluación que conducen a la mejora del diseño.
Se inicia la investigación de los antecedentes evaluando el estado de la tecnológica, recurriendo a maquinas ya realizadas, evaluando sus pro y contras, y rescatando lo necesario para un correcto diseño y automatización de la máquina que facilite su uso.
En el marco teórico observamos los principales conceptos que se debe tener para el diseño y automatización de la máquina.
En la explicación de los detalles, se presentó los documentos requeridos para el diseño de la máquina y ver la forma más sencilla de automatizarla.Trabajo de suficiencia profesionalCampus Lima Centr
Towards a plant-wide Benchmark Simulation Model with simultaneous nitrogen and phosphorus removal wastewater treatment processes.
It is more than 10 years since the publication of the Benchmark Simulation Model No 1 (BSM1) manual (Copp, 2002). The main objective of BSM1 was creating a platform for benchmarking carbon and nitrogen removal strategies in activated sludge systems. The initial platform evolved into BSM1_LT and BSM2, which allowed the evaluation of monitoring and plant-wide control strategies, respectively. The fact that the BSM platforms have resulted in 300+ publications demonstrates the interest for the tool within the scientific community. In this paper, an extension of the BSM2 is proposed. This extension aims at facilitating simultaneous carbon, nitrogen and phosphorus (P) removal process development and performance evaluation at a plant-wide level. The main motivation of the work is that numerous wastewater treatment plants (WWTPs) pursue biological phosphorus removal as an alternative to chemical P removal based on precipitation using metal salts, such as Fe or Al. This paper identifies and discusses important issues that need to be addressed to upgrade the BSM2 to BSM2-P, for example: 1) new influent wastewater characteristics; 2) new (bio) chemical processes to account for; 3) modifications of the original BSM2 physical plant layout; 4) new/upgraded generic mathematical models; 5) model integration; 6) new control handles/sensors; and 7) new extended evaluation criteria. The paper covers and analyzes all these aspects in detail, identifying the main bottlenecks that need to be addressed and finally discusses the aspects where scientific consensus is required
COVID-19 may lower quality of life when infections and deaths increase: A longitudinal study in the Peruvian jungle
"Background: Quality of life (QoL) is a multifactorial concept on the perception of the individual’s wellbeing underpinned by environmental, psychological, and physical factors. Several studies have shown changes in QoL in the COVID-19 pandemic and may be due to increases in mortality rates, however, no study has investigated this among Peruvian jungle dwellers. Here, we have sought to estimate the QoL of individuals before and after the increase in cases and deaths from COVID-19.
Methods: A questionnaire-based longitudinal study was conducted in 102 inhabitants (mean 40.75 ± 7.49 years). The Spanish version of the WHOQOL-BREF was used in two stages: April and June. The first stage was accomplished before the first confirmed case of COVID-19, and the second stage was when the daily mortality rate was 3.5% with an incidence of 87%.
Results: Sixty (54.8%) participants were women, 67 (61.9%) were >31 years, and 38 (34.5%) and 32 (29.1%) participants had primary and secondary education, respectively. In the first and second stage we obtained an overall mean QoL of 46.65 ± 23.2 and 35 ± 27.7 points, respectively. Individuals had significantly lower QoL in the face of increased deaths in physical (p = 0.001), mental (p = 0.028) and environmental (p = 0.001) health domains, with the latter having the greatest impact (51.84 ± 5.81 vs. 16.66 ± 5.55 points).
Conclusion: Quality of life of Peruvian jungle dwellers is reduced during periods of increased mortality and incidence by COVID-19. Preventive strategies aimed at reducing the impact of COVID-19 on the mental health and global wellbeing of individuals living in the Amazon are recommended to Peruvian authorities.
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