274 research outputs found
Time-dependent, long-term hydrodynamic simulations of the inner protoplanetary disk II: The importance of stellar rotation
The spin evolution of young protostars, surrounded by an accretion disk,
still poses problems for observations and theoretical models. In recent
studies, the importance of the magnetic star-disk interaction for stellar spin
evolution has been elaborated. The accretion disk in these studies, however, is
only represented by a simplified model and important features are not
considered. We combined the implicit hydrodynamic TAPIR disk code with a
stellar spin evolution model. The influence of stellar magnetic fields on the
disk dynamics, the radial position of the inner disk radius, as well as the
influence of stellar rotation on the disk were calculated self-consistently.
Within a defined parameter space, we can reproduce the majority of fast and
slow rotating stars observed in young stellar clusters. Additionally, the back
reaction of different stellar spin evolutionary tracks on the disk can be
analyzed. Disks around fast rotating stars are located closer to the star.
Consequently, the disk midplane temperature in the innermost disk region
increases significantly compared to slow rotating stars. We can show the
effects of stellar rotation on episodic accretion outbursts. The higher
temperatures of disks around fast rotating stars result in more outbursts and a
longer outbursting period over the disk lifetime. The combination of a
long-term hydrodynamic disk and a stellar spin evolution model allows the
inclusion of previously unconsidered effects such as the back-reaction of
stellar rotation on the long-term disk evolution and the occurrence of
accretion outbursts. However, a wider parameter range has to be studied to
further investigate these effects. Additionally, a possible interaction between
our model and a more realistic stellar evolution code (e.g., the MESA code) can
improve our understanding of the stellar spin evolution and its effects on the
pre-main sequence star.Comment: 12 pages, 7 figures, accepted by Astronomy & Astrophysic
Unveiling the Real Performance of LPDDR5 Memories
LPDDR5 is the latest low-power DRAM standard and expected to be used in
various application fields. The vendors have published promising peak
bandwidths up to 50 % higher than those of the predecessor LPDDR4. In this
paper we evaluate the best-case and worst-case real bandwidth utilization of
different LPDDR5 configurations and compare the results to corresponding LPDDR4
configurations. We also show that an upgrade from LPDDR4 to LPDDR5 does not
always bring a bandwidth advantage and that some LPDDR5 configurations should
be avoided for specific workloads.Comment: ACM/IEEE International Symposium on Memory Systems (MEMSYS 2022
A Framework for Formal Verification of DRAM Controllers
The large number of recent JEDEC DRAM standard releases and their increasing
feature set makes it difficult for designers to rapidly upgrade the memory
controller IPs to each new standard. Especially the hardware verification is
challenging due to the higher protocol complexity of standards like DDR5,
LPDDR5 or HBM3 in comparison with their predecessors. With traditional
simulation-based verification it is laborious to guarantee the coverage of all
possible states, especially for control flow rich memory controllers. This has
a direct impact on the time-to-market. A promising alternative is formal
verification because it allows to ensure protocol compliance based on
mathematical proofs. However, with regard to memory controllers no
fully-automated verification process has been presented in the state-of-the-art
yet, which means there is still a potential risk of human error. In this paper
we present a framework that automatically generates SystemVerilog Assertions
for a DRAM protocol. In addition, we show how the framework can be used
efficiently for different tasks of memory controller development.Comment: ACM/IEEE International Symposium on Memory Systems (MEMSYS 2022
Connecting atmospheric blocking to European temperature extremes in spring
Atmospheric blocking is an important contributor to European temperature variability. It can trigger cold and warm spells, which is of specific relevance in spring because vegetation is particularly vulnerable to extreme temperatures in the growing season. The spring season is investigated as a transition period from predominant connections of blocking with cold spells in winter to predominant connections of blocking with warm spells in summer. Extreme temperatures are termed cold or warm spells if temperature stays outside the 10th to 90th percentile range for at least six consecutive days. Cold and warm spells in Europe over 1979–2014 are analyzed in observations from the European daily high-resolution gridded dataset (E-OBS) and the connection to blocking is examined in geopotential height fields from ERA-Interim. A highly significant link between blocking and cold and warm spells is found that changes during spring. Blocking over the northeastern Atlantic and Scandinavia is correlated with the occurrence of cold spells in Europe, particularly early in spring, whereas blocking over central Europe is associated with warmer conditions, particularly from March onward. The location of the block also impacts the spatial distribution of temperature extremes. More than 80% of cold spells in southeastern Europe occur during blocking whereas warm spells are correlated with blocking mainly in northern Europe. Over the analysis period, substantial interannual variability is found but also a decrease in cold spells and an increase in warm spells. The long-term change to a warmer climate holds the potential for even higher vulnerability to spring cold extremes
Physician-assisted suicide and euthanasia: Emerging issues from a global perspective
Medical professional societies have traditionally opposed physician-assisted suicide and euthanasia (PAS-E), but this opposition may be shifting. We present 5 reasons why physicians shouldn’t be involved in PAS-E. 1. Slippery slopes: There is evidence that safeguards in the Netherlands and Belgium are ineffective and violated, including administering lethal drugs without patient consent, absence of terminal illness, untreated psychiatric diagnoses, and nonreporting; 2. Lack of self-determination: Psychological and social motives characterize requests for PAS-E more than physical symptoms or rational choices; many requests disappear with improved symptom control and psychological support; 3. Inadequate palliative care: Better palliative care makes most patients physically comfortable. Many individuals requesting PAS-E don’t want to die but to escape their suffering. Adequate treatment for depression and pain decreases the desire for death; 4. Medical professionalism: PAS-E transgresses the inviolable rule that physicians heal and palliate suffering but never intentionally inflict death; 5. Differences between means and ends: Proeuthanasia advocates look to the ends (the patient’s death) and say the ends justify the means; opponents disagree and believe that killing patients to relieve suffering is different from allowing natural death and is not acceptable. Conclusions: Physicians have a duty to eliminate pain and suffering, not the person with the pain and suffering. Solutions for suffering lie in improving palliative care and social conditions and addressing the reasons for PAS-E requests. They should not include changing medical practice to allow PAS-E
Animazione socioculturale dell'infanzia e della gioventù
This book presents an overview of the results of the first standardised survey of services of open child and youth work in Switzerland, which was conducted in 2018 as a sub-project of the project Language Regions of the umbrella organisation Open Child and Youth Work Switzerland (DOJ/AFAJ) and other cooperation partners and was published in the three national languages of Switzerland which are German, French and Italian. A total of 620 services of open child and youth work, in which at least one permanently employed and/or paid professional worked, took part in the survey. In the book, the following aspects of the field of action are described in an overview and then contextualised: Types of services, opportunities for participation, quality work, professional orientation, financing, sponsorship and governance and management structures, statements on the target group, clients and staff, as well as on spatial or financial resources, founding year, opening hours etc., but also assessments of the professionals on specific topics. The results were also compared between the different linguistic regions and in the three different types of communes "urban", "intermediate" and "rural". The results of the study show a picture of a differentiated and complex field of action, illustrate achievements to date and point out the potential for future development
Resilienz durch soziale Innovation: Erfolgsfaktoren und Barrieren von sozialen Innovationen in der Stadtregion Bern
Soziale Innovationen, definiert als neue Lösungen für soziale Probleme, können zur Resilienz einer Gesellschaft beitragen. Damit deren Potenzial genutzt werden kann, gilt es jedoch, die Erfolgsfaktoren und Barrieren bei der Umsetzung von sozialen Innovationen zu verstehen. Dieser Beitrag untersucht deshalb im Rahmen einer Interviewstudie die Erfolgsfaktoren und Barrieren für soziale Innovationen im Raum Bern und stellt heraus, wie konkret zur Förderung von sozialen Innovationen beigetragen werden kann
Offene Kinder- und Jugendarbeit
This book presents an overview of the results of the first standardised survey of services of open child and youth work in Switzerland, which was conducted in 2018 as a sub-project of the project Language Regions of the umbrella organisation Open Child and Youth Work Switzerland (DOJ/AFAJ) and other cooperation partners and was published in the three national languages of Switzerland which are German, French and Italian. A total of 620 services of open child and youth work, in which at least one permanently employed and/or paid professional worked, took part in the survey. In the book, the following aspects of the field of action are described in an overview and then contextualised: Types of services, opportunities for participation, quality work, professional orientation, financing, sponsorship and governance and management structures, statements on the target group, clients and staff, as well as on spatial or financial resources, founding year, opening hours etc., but also assessments of the professionals on specific topics. The results were also compared between the different linguistic regions and in the three different types of communes "urban", "intermediate" and "rural". The results of the study show a picture of a differentiated and complex field of action, illustrate achievements to date and point out the potential for future development
uncertainty and complexity in the context of COVID-19
Although the first coronavirus disease 2019 (COVID-19) wave has peaked with the second wave underway, the world is still struggling to manage potential systemic risks and unpredictability of the pandemic. A particular challenge is the “superspreading” of the virus, which starts abruptly, is difficult to predict, and can quickly escalate into medical and socio-economic emergencies that contribute to long-lasting crises challenging our current ways of life. In these uncertain times, organizations and societies worldwide are faced with the need to develop appropriate strategies and intervention portfolios that require fast understanding of the complex interdependencies in our world and rapid, flexible action to contain the spread of the virus as quickly as possible, thus preventing further disastrous consequences of the pandemic. We integrate perspectives from systems sciences, epidemiology, biology, social networks, and organizational research in the context of the superspreading phenomenon to understand the complex system of COVID-19 pandemic and develop suggestions for interventions aimed at rapid responses.publishersversionpublishe
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