1,753 research outputs found
N-version programming as an opportunity to exclude errors in software
One of the methods for increasing computer system dependability level is the N-version programming method. Liming Chen and Algirdas Avizienis proposed this concept with the main hypothesis that «independent efforts in software development will significantly reduce the likelihood of identical failures that occurs in two or more versions of the program». The main goal of N-version programming is to increase the reliability of the software by bounding design errors. The effectiveness of a multiversion system depends on the variety of variations at the executive teams formation stage, different algorithms implementation, design and testing tools.Одним із методів підвищення рівня гарантоздатності комп'ютерних систем є метод багатоверсійного програмування. Ця концепція була запропонована Лімінгом Ченом і Альгірдасом Авіженісом у вигляді основної гіпотези про те, що «незалежні зусилля при розробці програмного забезпечення значно зменшать імовірність ідентичних збоїв, що виникають у двох або більше версіях програми». Метою багатоверсійного програмування є підвищення надійності роботи програмного забезпечення за рахунок локалізації помилок проектування. Ефективність багатоверсійної системи залежить від різноманітності варіацій на етапах утворення груп виконавців, використання різних алгоритмів, засобів проектування та випробувань.Одним из методов повышения уровня гарантоспособности компьютерных систем является метод многоверсионного программирования. Эта концепция была предложена Лимингом Ченом и Альгирдасом Авиженисом в виде основной гипотезы о том, что «независимые усилия при разработке программного обеспечения значительно уменьшат вероятность идентичных сбоев, возникающих в двух или более версиях программы». Целью многоверсионного программирования является повышение надежности работы программного обеспечения за счет локализации ошибок проектирования. Эффективность многоверсионной системы зависит от разнообразия вариаций на этапах образования групп исполнителей, использования разных алгоритмов, средств проектирования и испытаний
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Automatic near real-time selection of flood water levels from high resolution Synthetic Aperture Radar images for assimilation into hydraulic models: a case study
Flood extents caused by fluvial floods in urban and rural areas may be predicted by hydraulic models. Assimilation may be used to correct the model state and improve the estimates of the model parameters or external forcing. One common observation assimilated is the water level at various points along the modelled reach. Distributed water levels may be estimated indirectly along the flood extents in Synthetic Aperture Radar (SAR) images by intersecting the extents with the floodplain topography. It is necessary to select a subset of levels for assimilation because adjacent levels along the flood extent will be strongly correlated. A method for selecting such a subset automatically and in near real-time is described, which would allow the SAR water levels to be used in a forecasting model. The method first selects candidate waterline points in flooded rural areas having low slope. The waterline levels and positions are corrected for the effects of double reflections between the water surface and emergent vegetation at the flood edge. Waterline points are also selected in flooded urban areas away from radar shadow and layover caused by buildings, with levels similar to those in adjacent rural areas. The resulting points are thinned to reduce spatial autocorrelation using a top-down clustering approach. The method was developed using a TerraSAR-X image from a particular case study involving urban and rural flooding. The waterline points extracted proved to be spatially uncorrelated, with levels reasonably similar to those determined manually from aerial photographs, and in good agreement with those of nearby gauges
Functional bold MRI: advantages of the 3 T vs. the 1.5 T
We quantitatively evaluate the benefits of a higher field strength for functional
brain MRI (fMRI) based on the blood oxygenation level-dependent contrast. The 3-T
fMRI shows a higher sensitivity for the motor and somatosensory stimulation and
more specific localization in the grey substance. The 3-T fMRI detects additional
areas of activation with the motor paradigm
The SARS-CoV-2 Pandemic Impacts the Management of Swiss Pediatric Intensive Care Units.
The impact of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic on pediatric intensive care units (PICUs) is difficult to quantify. We conducted an observational study in all eight Swiss PICUs between 02/24/2020 and 06/15/2020 to characterize the logistical and medical aspects of the pandemic and their impact on the management of the Swiss PICUs. The nine patients admitted to Swiss PICUs during the study period suffering from pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) and constituting 14% (9/63) of all SARS-CoV-2 positive hospitalized patients in Swiss children's hospitals caused a higher workload [total Nine Equivalents of nursing Manpower use Score (NEMS) points, p = 0.0008] and were classified to higher workload categories (p < 0.0001) than regular PICU patients (n = 4,881) admitted in 2019. The comparison of the characteristics of the eight Swiss PICUs shows that they were confronted by different organizational issues arising from temporary regulations put in place by the federal council. These general regulations had different consequences for the eight individual PICUs due to the differences between the PICUs. In addition, the temporal relationship of these different regulations influenced the available PICU resources, dependent on the characteristics of the individual PICUs. As pandemic continues, reflecting and learning from experience is essential to reduce workload, optimize bed occupancy and manage resources in each individual PICU. In a small country as Switzerland, with a relatively decentralized health care local differences between PICUs are considerable and should be taken into account when making policy decisions
Bottom Effect in Atomic Force Microscopy Nanomechanics
In this work, the influence of the rigid substrate on the determination of the sample Young''s modulus, the so-called bottom-effect artifact, is demonstrated by an atomic force microscopy force-spectroscopy experiment. The nanomechanical properties of a one-component supported lipid membrane (SLM) exhibiting areas of two different thicknesses are studied: While a standard contact mechanics model (Sneddon) provides two different elastic moduli for these two morphologies, it is shown that Garcia''s bottom-effect artifact correction yields a unique value, as expected for an intrinsic material property. Remarkably, it is demonstrated that the ratio between the contact radius (and not only the indentation) and the sample thickness is the key parameter addressing the relevance of the bottom-effect artifact. The experimental results are validated by finite element method simulations providing a solid support to Garcia''s theory. The amphiphilic nature of the investigated material is representative of several kinds of lipids, suggesting that the results have far reaching implications for determining the correct Young''s modulus of SLMs. The generality of Garcia''s bottom-effect artifact correction allows its application to every kind of supported soft film
Infratentorial hygroma secondary to decompressive craniectomy after cerebellar infarction
We present a case of expansive CSF collection in the cerebellar convexity. The patient was a 74 years old lady who one month before had suffered a cerebellar infarct complicated with acute hydrocephalus. She had good evolution after decompressive craniectomy without shunting. Fifteen days after surgery, the patient started with new positional vertigo, nausea and vomiting and a wound CSF fistula that needed ventriculoperitoneal shunt (medium pressure) because conservative treatment failed. After shunting, the fistula closed, but the patient symptoms worsened. The MRI showed normal ventricular size with a cerebellar hygroma, extending to the posterior interhemispheric fissure. The collection had no blood signal and expanded during observation. A catheter was implanted in the collection and connected to the shunt. The patient became asymptomatic after surgery, and the hygromas had disappeared in control CT at one month. This case shows an infrequent problem of CSF circulation at posterior fossa that resulted in vertigo of central origin. A higroma-ventricle-peritoneal shunt solved the symptoms of the patient
Acute Myeloid Leukemia: Focus on Novel Therapeutic Strategies
Acute myeloid leukemia (AML) is a heterogeneous disease with variable clinical outcomes. Cytogenetic analysis reveals which patients may have favorable risk disease, but 5-year survival in this category is only approximately 60%, with intermediate and poor risk groups faring far worse. Advances in our understanding of the biology of leukemia pathogenesis and prognosis have not been matched with clinical improvements. Unsatisfactory outcomes persist for the majority of patients with AML, particularly the elderly. Novel agents and treatment approaches are needed in the induction, post-remission and relapsed settings. The additions of clofarabine for relapsed or refractory disease and the hypomethylating agents represent recent advances. Clinical trials of FLT3 inhibitors have yielded disappointing results to date, with ongoing collaborations attempting to identify the optimal role for these agents. Potential leukemia stem cell targeted therapies and treatments in the setting of minimal residual disease are also under investigation. In this review, we will discuss recent advances in AML treatment and novel therapeutic strategies
SentiCircles for contextual and conceptual semantic sentiment analysis of Twitter
Lexicon-based approaches to Twitter sentiment analysis are gaining much popularity due to their simplicity, domain independence, and relatively good performance. These approaches rely on sentiment lexicons, where a collection of words are marked with fixed sentiment polarities. However, words’ sentiment orientation (positive, neural, negative) and/or sentiment strengths could change depending on context and targeted entities. In this paper we present SentiCircle; a novel lexicon-based approach that takes into account the contextual and conceptual semantics of words when calculating their sentiment orientation and strength in Twitter. We evaluate our approach on three Twitter datasets using three different sentiment lexicons. Results show that our approach significantly outperforms two lexicon baselines. Results are competitive but inconclusive when comparing to state-of-art SentiStrength, and vary from one dataset to another. SentiCircle outperforms SentiStrength in accuracy on average, but falls marginally behind in F-measure
A Mixed-Integer Linear Programming Model for Transportation Planning in the Full Truck Load Strategy to Supply Products with Unbalanced Demand in the Just in Time Context: A Case Study
[EN] Growing awareness in cutting transport costs and minimizing the environmental impact means that companies are increasingly interested in using the full truck load strategy in their supply tasks. This strategy consists of filling trucks completely with one product type or a mixture of products from the same supplier. This paper aims to propose a mixed-integer linear programming model and procedure to fill trucks which considers limitations of stocks, stock levels and unbalanced demand and minimization of the total number of trucks used in the full truck load strategy. The results obtained from a case study are presented and are exported in a conventional spreadsheet available for a company in the automotive industry.Maheut ., JP.; García Sabater, JP. (2013). A Mixed-Integer Linear Programming Model for Transportation Planning in the Full Truck Load Strategy to Supply Products with Unbalanced Demand in the Just in Time Context: A Case Study. IFIP Advances in Information and Communication Technology. 397:576-583. doi:10.1007/978-3-642-40361-3_73S576583397Bitran, G.R., Haas, E.A., Hax, A.C.: Hierarchical production planning: a single stage system. Operations Research 29, 717–743 (1981)Sun, H., Ding, F.Y.: Extended data envelopment models and a practical tool to analyse product complexity related to product variety for an automobile assembly plant. International Journal of Logistics Systems and Management 6, 99–112 (2010)Boysen, N., Fliedner, M.: Cross dock scheduling: Classification, literature review and research agenda. Omega 38, 413–422 (2010)Garcia-Sabater, J.P., Maheut, J., Garcia-Sabater, J.J.: A two-stage sequential planning scheme for integrated operations planning and scheduling system using MILP: the case of an engine assembler. Flexible Services and Manufacturing Journal 24, 171–209 (2012)Ben-Khedher, N., Yano, C.A.: The Multi-Item Replenishment Problem with Transportation and Container Effects. Transportation Science 28, 37–54 (1994)Cousins, P.D.: Supply base rationalisation: myth or reality? European Journal of Purchasing Supply Management 5, 143–155 (1999)Kiesmüller, G.P.: A multi-item periodic replenishment policy with full truckloads. International Journal of Production Economics 118, 275–281 (2009)Goetschalckx, M.: Transportation Systems Supply Chain Engineering, vol. 161, pp. 127–154. Springer, US (2011)Liu, R., Jiang, Z., Fung, R.Y.K., Chen, F., Liu, X.: Two-phase heuristic algorithms for full truckloads multi-depot capacitated vehicle routing problem in carrier collaboration. Computers Operations Research 37, 950–959 (2010)Arunapuram, S., Mathur, K., Solow, D.: Vehicle Routing and Scheduling with Full Truckloads. Transportation Science 37, 170–182 (2003
Surgery guided by 5-aminolevulinic fluorescence in glioblastoma: volumetric analysis of extent of resection in singlecenter experience
We analyzed the efficacy and applicability of surgery guided by 5-aminolevulinic
acid (ALA) fluorescence in consecutive patients with glioblastoma multiforme
(GBM). Thirty-six patients with GBM were operated on using ALA fluorescence.
Resections were performed using the fluorescent light to assess the right plane
of dissection. In each case, biopsies with different fluorescent quality were
taken from the tumor center, from the edges, and from the surrounding tissue.
These samples were analyzed separately with hematoxylin-eosin examination and
immunostaining against Ki67. Tumor volume was quantified with pre- and
postoperative volumetric magnetic resonance imaging. Strong fluorescence
identified solid tumor with 100% positive predictive value. Invaded tissue beyond
the solid tumor mass was identified by vague fluorescence with 97% positive
predictive value and 66% negative predictive value, measured against
hematoxylin-eosin examination. All the contrast-enhancing volume was resected in
83.3% of the patients, all patients had resection over 98% of the volume and mean
volume resected was 99.8%. One month after surgery there was no mortality, and
new or increased neurological morbidity was 8.2%. The fluorescence induced by
5-aminolevulinic can help to achieve near total resection of enhancing tumor
volume in most surgical cases of GBM. It is possible during surgery to obtain
separate samples of the infiltrating cells from the tumor borde
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