7 resultados para Parallel hyperspectral unmixing method

em BORIS: Bern Open Repository and Information System - Berna - Suiça


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The various meanings of discourse connectives like while and however are difficult to identify and annotate, even for trained human annotators. This problem is all the more important that connectives are salient textual markers of cohesion and need to be correctly interpreted for many NLP applications. In this paper, we suggest an alternative route to reach a reliable annotation of connectives, by making use of the information provided by their translation in large parallel corpora. This method thus replaces the difficult explicit reasoning involved in traditional sense annotation by an empirical clustering of the senses emerging from the translations. We argue that this method has the advantage of providing more reliable reference data than traditional sense annotation. In addition, its simplicity allows for the rapid constitution of large annotated datasets.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

OBJECTIVE: A previous study of radiofrequency neurotomy of the articular branches of the obturator nerve for hip joint pain produced modest results. Based on an anatomical and radiological study, we sought to define a potentially more effective radiofrequency method. DESIGN: Ten cadavers were studied, four of them bilaterally. The obturator nerve and its articular branches were marked by wires. Their radiological relationship to the bone structures on fluoroscopy was imaged and analyzed. A magnetic resonance imaging (MRI) study was undertaken on 20 patients to determine the structures that would be encountered by the radiofrequency electrode during different possible percutaneous approaches. RESULTS: The articular branches of the obturator nerve vary in location over a wide area. The previously described method of denervating the hip joint did not take this variation into account. Moreover, it approached the nerves perpendicularly. Because optimal coagulation requires electrodes to lie parallel to the nerves, a perpendicular approach probably produced only a minimal lesion. In addition, MRI demonstrated that a perpendicular approach is likely to puncture femoral vessels. Vessel puncture can be avoided if an oblique pass is used. Such an approach minimizes the angle between the target nerves and the electrode, and increases the likelihood of the nerve being captured by the lesion made. Multiple lesions need to be made in order to accommodate the variability in location of the articular nerves. CONCLUSIONS: The method that we described has the potential to produce complete and reliable nerve coagulation. Moreover, it minimizes the risk of penetrating the great vessels. The efficacy of this approach should be tested in clinical trials.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Due to the ongoing trend towards increased product variety, fast-moving consumer goods such as food and beverages, pharmaceuticals, and chemicals are typically manufactured through so-called make-and-pack processes. These processes consist of a make stage, a pack stage, and intermediate storage facilities that decouple these two stages. In operations scheduling, complex technological constraints must be considered, e.g., non-identical parallel processing units, sequence-dependent changeovers, batch splitting, no-wait restrictions, material transfer times, minimum storage times, and finite storage capacity. The short-term scheduling problem is to compute a production schedule such that a given demand for products is fulfilled, all technological constraints are met, and the production makespan is minimised. A production schedule typically comprises 500–1500 operations. Due to the problem size and complexity of the technological constraints, the performance of known mixed-integer linear programming (MILP) formulations and heuristic approaches is often insufficient. We present a hybrid method consisting of three phases. First, the set of operations is divided into several subsets. Second, these subsets are iteratively scheduled using a generic and flexible MILP formulation. Third, a novel critical path-based improvement procedure is applied to the resulting schedule. We develop several strategies for the integration of the MILP model into this heuristic framework. Using these strategies, high-quality feasible solutions to large-scale instances can be obtained within reasonable CPU times using standard optimisation software. We have applied the proposed hybrid method to a set of industrial problem instances and found that the method outperforms state-of-the-art methods.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper presents a parallel surrogate-based global optimization method for computationally expensive objective functions that is more effective for larger numbers of processors. To reach this goal, we integrated concepts from multi-objective optimization and tabu search into, single objective, surrogate optimization. Our proposed derivative-free algorithm, called SOP, uses non-dominated sorting of points for which the expensive function has been previously evaluated. The two objectives are the expensive function value of the point and the minimum distance of the point to previously evaluated points. Based on the results of non-dominated sorting, P points from the sorted fronts are selected as centers from which many candidate points are generated by random perturbations. Based on surrogate approximation, the best candidate point is subsequently selected for expensive evaluation for each of the P centers, with simultaneous computation on P processors. Centers that previously did not generate good solutions are tabu with a given tenure. We show almost sure convergence of this algorithm under some conditions. The performance of SOP is compared with two RBF based methods. The test results show that SOP is an efficient method that can reduce time required to find a good near optimal solution. In a number of cases the efficiency of SOP is so good that SOP with 8 processors found an accurate answer in less wall-clock time than the other algorithms did with 32 processors.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

OBJECTIVES Primary care physicians (PCPs) should prescribe faecal immunochemical testing (FIT) or colonoscopy for colorectal cancer screening based on their patient's values and preferences. However, there are wide variations between PCPs in the screening method prescribed. The objective was to assess the impact of an educational intervention on PCPs' intent to offer FIT or colonoscopy on an equal basis. DESIGN Survey before and after training seminars, with a parallel comparison through a mailed survey to PCPs not attending the training seminars. SETTING All PCPs in the canton of Vaud, Switzerland. PARTICIPANTS Of 592 eligible PCPs, 133 (22%) attended a seminar and 106 (80%) filled both surveys. 109 (24%) PCPs who did not attend the seminars returned the mailed survey. INTERVENTION A 2 h-long interactive seminar targeting PCP knowledge, skills and attitudes regarding offering a choice of colorectal cancer (CRC) screening options. OUTCOME MEASURES The primary outcome was PCP intention of having their patients screened with FIT and colonoscopy in equal proportions (between 40% and 60% each). Secondary outcomes were the perceived role of PCPs in screening decisions (from paternalistic to informed decision-making) and correct answer to a clinical vignette. RESULTS Before the seminars, 8% of PCPs reported that they had equal proportions of their patients screened for CRC by FIT and colonoscopy; after the seminar, 33% foresaw having their patients screened in equal proportions (p<0.001). Among those not attending, there was no change (13% vs 14%, p=0.8). Of those attending, there was no change in their perceived role in screening decisions, while the proportion responding correctly to a clinical vignette increased (88-99%, p<0.001). CONCLUSIONS An interactive training seminar increased the proportion of physicians with the intention to prescribe FIT and colonoscopy in equal proportions.