563 research outputs found
Fluid flow and heat transfer simulation of an electro hydraulic actuator
Every technological system has to be improved and developed with time to stay competitive in the market. These means anticipate and solvent every possible problem that can appear in a mechanical system and propose new features and characteristics.
Since the appearance of mechanised rail transport systems appeared in England in the 1820s, train transport system has been continuously developing. The introduction of high-speed rail passenger service between metropolitan areas has stimulated considerable interest in the effects of vibration on passenger comfort.
Vibrations are caused by track irregularities, and reduction of these vibrations at high speeds is a particularly difficult task. The high and increasing demand of requisite for this transport have encouraged research in many different areas that affect rail transport. One of these areas is the dampening system, especially in passenger trains.
Due to internal heat generation and the influence of external temperatures, inside the actuator can be established temperatures that can affect the efficiency of the different elements from the actuator. So an imperative is to have a total control of the development of temperatures inside.
The knowledge of the thermal behaviour of the actuator is performed through a Computational Fluid Dynamics (CFD) simulation, in this case with STAR-CCM+ software. Through this a detailed thermal analysis of the entire system is possible. The main objectives with this simulation are the study of heat transfer in different load simulations and varying model conditions to study how this effect the general solution. After implementing this changes, analysis from heat distribution, maximum temperatures and detection of hot spot
LANGUAGE IMPORTANCE SCORE
A system and method are disclosed for classifying videos based on a Language Importance Score (LIS) indicating how important it is to understand a certain language to be able to understand a given video. The method extracts video features directly from the video after it has been uploaded rather than by analysing viewing patterns from logs. The level of LIS is classified as LOW, MID, or HIGH based on the degree of ease for a user to understand. Global/multilingual video platforms can use this system to optimize search to improve viewer experience effectively
Language Importance Score
A system and method are disclosed for classifying videos based on a Language Importance Score (LIS) indicating how important it is to understand a certain language to be able to understand a given video. The method extracts video features directly from the video after it has been uploaded rather than by analysing viewing patterns from logs. The level of LIS is classified as LOW, MID, or HIGH based on the degree of ease for a user to understand. Global/multilingual video platforms can use this system to optimize search to improve viewer experience effectively
Developing Methods For Designing Shape Memory Alloy Actuated Morphing Aerostructures
The past twenty years have seen the successful characterization and computational modeling efforts by the smart materials community to better understand the Shape Memory Alloy (SMA). Commercially available numerical analysis tools, coupled with powerful constitutive models, have been shown to be highly accurate for predicting the response of these materials when subjected to predetermined loading conditions. This thesis acknowledges the development of such an established analysis framework and proposes an expanded design framework that is capable of accounting for the complex coupling behavior between SMA components and the surrounding assembly or system. In order to capture these effects, additional analysis tools are implemented in addition to the standard use of the non-linear finite element analysis (FEA) solver and a full, robust SMA constitutive model coded as a custom user-defined material subroutine (UMAT). These additional tools include a computational fluid dynamics (CFD) solver, a cosimulation module that allows separate FEA and CFD solvers to iteratively analyze fluid-structure interaction (FSI) and conjugate heat transfer (CHT) problems, and the addition of the latent heat term to the heat equations in the UMAT to fully account for transient thermomechanical coupling. Procedures for optimizing SMA component and assembly designs through iterative analysis are also introduced at the highest level. These techniques are implemented using commercially available simulation process management and scripting tools. The expanded framework is demonstrated on example engineering problems that are motivated by real morphing structure applications, namely the Boeing Variable Geometry Chevron (VGC) and the NASA Shape Memory Alloy Hybrid Composite (SMAHC) chevron. Three different studies are conducted on these applications, focusing on component-, assembly-, and system-level analysis, each of which may necessitate accounting for certain coupling interactions between thermal, mechanical, and fluid fields. Output analysis data from each of the three models are validated against experimental data, where available. It is shown that the expanded design framework can account for the additional coupling effects at each analysis level, while providing an efficient and accurate alternative to the cost- and time-expensive legacy design-build-test methods that are still used today to engineer SMA actuated morphing aerostructures
Can PSMA PET/CT help in dose-tailoring in post-prostatectomy radiotherapy?
There are few randomized trials to evaluate the use of PSMA-PET in the planning of post-prostatectomy radiotherapy. There are two unresolved questions 1) should we increase the dose to lesions visible on PSMA-PET 2) can we reduce dose in the case of a negative PSMA-PET. In this review, we summarize and discuss the available evidence in the literature. We found that in general, there seems to be an advantage for dose-increase, but ta large recent study from the pre-PSMA era didn't show an advantage for dose escalation. Retrospective studies have shown that conventional doses to PSMA-PET-positive lesions seem sufficient. On the other hand, in the case of a negative PSMA-PET, there is no evidence that dose-reduction is possible. In the future, the combination of PSMA-PET with genomic classifiers could help in better identify patients who might benefit from either dose- de-or -increase. We further need to identify intraindividual references to help identify lesions with higher aggressiveness
Cee-16: A Cluster Analysis Based on Tourism Competitiveness and Correlations With Major Determinants
The purpose of this paper is to identify the main groups of CEE-16 countries in terms of tourism competitiveness. Competitiveness, as part of the supply side, is addressed in view of the supply-demand correlations, and we consider the attractiveness of tourist destinations from the tourists’ perspective as the link between the two sides. For the analysis are selected exactly the 16 countries participating in the 16+1 platform initiated by China in 2011, tourism being one of the components of sectoral cooperation in this framework. We demonstrate that tourism infrastructure (its upgrading and development) is one of the main determinants of tourism competitiveness, even surpassing in importance the tourism assets. In this context, the “China factor” might play a significant role for the CEE-16 in terms of spurring competitiveness, as it is not antagonistic, but complementary with other determinants of competitiveness, including the EU funds. From the perspective of attractiveness, 16+1 cooperation can boost Chinese tourists’ arrivals in the region. In order to test these hypotheses, as part of the methodology, the authors calculate a specific travel and tourism competitiveness index (STTCI), starting from the main objectives of the 16+1 cooperation platform, namely prioritization, openness, environmental sustainability, transport infrastructure and specific infrastructure for tourism services. The authors correlate this STTCI with other qualitative indicators and obtain two categories of clusters among the CEE-16 countries. In Romania’s case, one can remark the following paradox. The cumulative amount of investment in tourism during 2000-2017 is the largest among the CEE-16 countries, corresponding to its tourism assets and the necessity to connect them; however, Romania lags behind most of the analyzed countries in terms of qualitative indicators such as revealed comparative advantage, direct productivity and multiplier effect of GDP. Therefore, the cluster it belongs to does not reflect its real tourism asset
Can PSMA PET/CT help in dose-tailoring in post-prostatectomy radiotherapy?
There are few randomized trials to evaluate the use of PSMA-PET in the planning of post-prostatectomy radiotherapy. There are two unresolved questions 1) should we increase the dose to lesions visible on PSMA-PET 2) can we reduce dose in the case of a negative PSMA-PET. In this review, we summarize and discuss the available evidence in the literature. We found that in general, there seems to be an advantage for dose-increase, but ta large recent study from the pre-PSMA era didn’t show an advantage for dose escalation. Retrospective studies have shown that conventional doses to PSMA-PET-positive lesions seem sufficient. On the other hand, in the case of a negative PSMA-PET, there is no evidence that dose-reduction is possible. In the future, the combination of PSMA-PET with genomic classifiers could help in better identify patients who might benefit from either dose- de-or -increase. We further need to identify intraindividual references to help identify lesions with higher aggressiveness
Influencing Factors on Radiotherapy Outcome in Stage I-II Glottic Larynx Cancer—A Multicenter Study
Background and Purpose: Larynx cancer represents one of the most frequently diagnosed head and neck malignancies, which is most often confined to the glottic area. The aim of this study was to report the oncological outcome and identify prognostic factors in early-stage glottic squamous cell carcinoma treated with radiotherapy. Material and Methods: Patients (n = 761) diagnosed and treated in 10 centers between 1990 and 2015 were retrospectively analyzed. Probabilities of loco-regional control (LRC) and overall survival (OS) were calculated and possible prognostic factors were analyzed using Cox proportional hazards models. Results: The median follow-up was 63 months (range: 2-243). Three hundred and sixty-four, 148 and 249 patients had cT1a, cT1b, and cT2 stage I-II disease, respectively. Five and 10-years LRC/OS rates in the whole cohort were 83/82% and 80/68%, respectively. Three patients developed distant recurrences. In univariate analysis, male sex (HR: 3.49; 95% CI: 1.47-11.37; p < 0.01), T2 vs. T1a (HR: 1.62; 95% CI: 1.08-2.43; p = 0.02) and anterior commissure involvement (ACI) (HR: 1.66; 95% CI: 1.38-2.45; p < 0.01) were associated with impaired LRC. In multivariate analysis, male sex (HR: 3.42; 95% CI: 1.44-11.17; p < 0.01) and ACI (HR: 1.51; 95% CI: 1.01-2.28; p = 0.047) remained poor prognostic factors. No relation of treatment technique and biologically equivalent dose (BED) to oncological outcome was identified except for higher BED10(L = 25; T = 1) yielding better LRC in T1a tumors (p = 0.04) in univariate analyses. Conclusion: Our results highlight the negative impact of ACI on tumor control. A less-expected finding was the impact of sex on tumor control. Further research is needed to validate its prognostic value and investigate any related biologic or behavioral factors, which may be modified to improve oncologic outcome
Comprehensive Monitoring of Wildfires in Europe: The European Forest Fire Information System (EFFIS)
Genomic structural variations lead to dysregulation of important coding and non-coding RNA species in dilated cardiomyopathy
The transcriptome needs to be tightly regulated by mechanisms that include transcription factors, enhancers, and repressors as well as non-coding RNAs. Besides this dynamic regulation, a large part of phenotypic variability of eukaryotes is expressed through changes in gene transcription caused by genetic variation. In this study, we evaluate genome-wide structural genomic variants (SVs) and their association with gene expression in the human heart. We detected 3,898 individual SVs affecting all classes of gene transcripts (e.g., mRNA, miRNA, lncRNA) and regulatory genomic regions (e.g., enhancer or TFBS). In a cohort of patients (n = 50) with dilated cardiomyopathy (DCM), 80,635 non-protein-coding elements of the genome are deleted or duplicated by SVs, containing 3,758 long non-coding RNAs and 1,756 protein-coding transcripts. 65.3% of the SV-eQTLs do not harbor a significant SNV-eQTL, and for the regions with both classes of association, we find similar effect sizes. In case of deleted protein-coding exons, we find downregulation of the associated transcripts, duplication events, however, do not show significant changes over all events. In summary, we are first to describe the genomic variability associated with SVs in heart failure due to DCM and dissect their impact on the transcriptome. Overall, SVs explain up to 7.5% of the variation of cardiac gene expression, underlining the importance to study human myocardial gene expression in the context of the individual genome. This has immediate implications for studies on basic mechanisms of cardiac maladaptation, biomarkers, and (gene) therapeutic studies alike
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