221 research outputs found
Computation of Buffer Capacities for Throughput Constrained and Data Dependent Inter-Task Communication
Streaming applications are often implemented as task graphs. Currently, techniques exist to derive buffer capacities that guarantee satisfaction of a throughput constraint for task graphs in which the inter-task communication is data-independent, i.e. the amount of data produced and consumed is independent of the data values in the processed stream. This paper presents a technique to compute buffer capacities that satisfy a throughput constraint for task graphs with data dependent inter-task communication, given that the task graph is a chain. We demonstrate the applicability of the approach by computing buffer capacities for an MP3 playback application, of which the MP3 decoder has a variable consumption rate. We are not aware of alternative approaches to compute buffer capacities that guarantee satisfaction of the throughput constraint for this application
Buffer Capacity Computation for Throughput Constrained Streaming Applications with Data-Dependent Inter-Task Communication
Streaming applications are often implemented as task graphs, in which data is communicated from task to task over buffers. Currently, techniques exist to compute buffer capacities that guarantee satisfaction of the throughput constraint if the amount of data produced and consumed by the tasks is known at design-time. However, applications such as audio and video decoders have tasks that produce and consume an amount of data that depends on the decoded stream. This paper introduces a dataflow model that allows for data-dependent communication, together with an algorithm that computes buffer capacities that guarantee satisfaction of a throughput constraint. The applicability of this algorithm is demonstrated by computing buffer capacities for an H.263 video decoder
Electric Field Control of Shallow Donor Impurities in Silicon
We present a tight-binding study of donor impurities in Si, demonstrating the
adequacy of this approach for this problem by comparison with effective mass
theory and experimental results. We consider the response of the system to an
applied electric field: donors near a barrier material and in the presence of
an uniform electric field may undergo two different ionization regimes
according to the distance of the impurity to the Si/barrier interface. We show
that for impurities ~ 5 nm below the barrier, adiabatic ionization is possible
within switching times of the order of one picosecond, while for impurities ~
10 nm or more below the barrier, no adiabatic ionization may be carried out by
an external uniform electric field. Our results are discussed in connection
with proposed Si:P quantum computer architectures.Comment: 18 pages, 6 figures, submitted to PR
Onderbouwing wateropgave Haarlemmermeerpolder; modelbouw, kalibratie en scenarioanalyse
Ten behoeve van de Onderbouwing Wateropgave Noord-Holland is door Alterra in opdracht van het Hoogheemraadschap van Rijnland (HHR) een studie uitgevoerd naar de watervraag in de Haarlemmermeer. Hiertoe is een model opgezet voor water- en chloride-transport van de Haarlemmermeer. Gezien de doelstelling van het project is voor het modelinstrument FIWMultiSwap gekozen. Verschillende scenario's zijn met het model doorgerekend en geïnterpreteerd voor de wateropgav
Skin advanced glycation end product accumulation is poorly refected by glycemic control in type 2 diabetic patients (ZODIAC-9)
Background: Glycemic memory can be reflected by tissue accumulation of advanced glycation end products (AGEs). In type 1 diabetes mellitus (T1DM) patients, hemoglobin A1c (HbA1c) levels over various time periods poorly predicted the accumulation of different AGEs in skin biopsies. Our aim was to investigate whether HbA1c assessments can predict the change in skin AGEs during time in type 2 diabetes mellitus (T2DM). Methods: We included 452 T2DM patients participating in a shared-care setting, who are screened annually for HbA1c and diabetic complications. Baseline and follow-up levels of skin AGEs were assessed with a validated noninvasive autofluorescence (AF) method, which is based on the fluorescence characteristics of certain AGEs. Results: Our study population had a mean age of 65 years and 54% were female. After a mean follow-up duration of 3.3 years, linear regression analyses showed weak relationships among different assessments of HbA1c (baseline, maximum, mean, and variance of HbA1c) and skin AF at follow-up. Baseline skin AF and age were predictors of skin AF at follow-up, but diabetes duration, smoking, and creatinine were of less or no predictive value for skin AF at follow-up. Conclusions: In our T2DM population, integrated HbA1c assessments over years poorly predict the change in skin AGE level measured by skin AF. These findings agree with results in patients with T1DM. This suggests either the need for longer exposure to glucose disturbances to change tissue AGEs or other mechanisms, such as oxidative stress, leading to AGE accumulation.</p
Конкуренція університетів: світовий досвід і українські реалії
Досліджено процеси конкуренції вищих навчальних закладів; обґрунтовано основні критерії формування рейтингів університетів; виявлено взаємозв’язок між високим рейтингом університету і показником його елітності; розкрито значення капіталізації в конкурентних перевагах вищих навчальних закладів; визначено роль елітних університетів у постіндустріальному розвитку суспільства.Исследованы процессы конкуренции высших учебных заведений; обоснованы основные критерии формирования рейтингов университетов; показана взаимосвязь между высоким рейтингом университета и показателем его элитности; раскрыто значение капитализации в конкурентных преимуществах высших учебных заведений; определена роль элитных университетов в постиндустриальном развитии общества.The processes of competition of universities are studi ed, proved the main criteria for the formation of university rankings, found the relationship between highly-rated university and the rate of its elite, disclosed the value of capitalization in the competitive advantages of higher education institutions, and determined the role of elite universities in the post-industrial development
Zoeken naar een indicator voor mobiel N in de bodem
De nitraatconcentraties in het grondwater zijn op veel plaatsen in Nederland te hoog. Verandering in bemestingsbeleid zullen naar verwachting effect hebben op nitraatuitspoeling naar grondwater en oppervlaktewater. Monitoren van nitraatconcentraties in het grondwater is echter zeer arbeidsintensief. Daarom is gezocht naar een bodemparameter, die reageert op veranderingen in bemesting en daarom als indicator voor verandering in nitraatuitspoeling kan dienen. Bodemmonsters zijn genomen in langjarige bemestingsproeven en diverse bodemparameters zijn gemeten en vergeleken. Geen van de parameters gaf een duidelijke reactie op bemesting. De nitraatconcentratie in het grondwater reageerde wel. Dit lijkt de beste indicator voor uitspoeling te zijn
Calibration of the length of a chain of single gold atoms
Using a scanning tunneling microscope or mechanically controllable break
junctions it has been shown that it is possible to control the formation of a
wire made of single gold atoms. In these experiments an interatomic distance
between atoms in the chain of ~3.6 Angstrom was reported which is not
consistent with recent theoretical calculations. Here, using precise
calibration procedures for both techniques, we measure length of the atomic
chains. Based on the distance between the peaks observed in the chain length
histogram we find the mean value of the inter-atomic distance before chain
rupture to be 2.6 +/- 0.2 A . This value agrees with the theoretical
calculations for the bond length. The discrepancy with the previous
experimental measurements was due to the presence of He gas, that was used to
promote the thermal contact, and which affects the value of the work function
that is commonly used to calibrate distances in scanning tunnelling microscopy
and mechanically controllable break junctions at low temperatures.Comment: 6 pages, 6 figure
Decoherence in elastic and polaronic transport via discrete quantum states
Here we study the effect of decoherence on elastic and polaronic transport
via discrete quantum states. The calculations are performed with the help of
nonperturbative computational scheme, based on the Green's function theory
within the framework of polaron transformation (GFT-PT), where the many-body
electron-phonon interaction problem is mapped exactly into a single-electron
multi-channel scattering problem. In particular, the influence of dephasing and
relaxation processes on the shape of the electrical current and shot noise
curves is discussed in detail under the linear and nonlinear transport
conditions.Comment: 11 pages, 3 figure
Treatment Guidance for Patients With Lung Cancer During the Coronavirus 2019 Pandemic.
The global coronavirus disease 2019 pandemic continues to escalate at a rapid pace inundating medical facilities and creating substantial challenges globally. The risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in patients with cancer seems to be higher, especially as they are more likely to present with an immunocompromised condition, either from cancer itself or from the treatments they receive. A major consideration in the delivery of cancer care during the pandemic is to balance the risk of patient exposure and infection with the need to provide effective cancer treatment. Many aspects of the SARS-CoV-2 infection currently remain poorly characterized and even less is known about the course of infection in the context of a patient with cancer. As SARS-CoV-2 is highly contagious, the risk of infection directly affects the cancer patient being treated, other cancer patients in close proximity, and health care providers. Infection at any level for patients or providers can cause considerable disruption to even the most effective treatment plans. Lung cancer patients, especially those with reduced lung function and cardiopulmonary comorbidities are more likely to have increased risk and mortality from coronavirus disease 2019 as one of its common manifestations is as an acute respiratory illness. The purpose of this manuscript is to present a practical multidisciplinary and international overview to assist in treatment for lung cancer patients during this pandemic, with the caveat that evidence is lacking in many areas. It is expected that firmer recommendations can be developed as more evidence becomes available
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