Monitoring Cropland Phenology on Google Earth Engine Using Gaussian Process Regression

Monitoring cropland phenology from optical satellite data remains a challenging task due to the influence of clouds and atmospheric artifacts. Therefore, measures need to be taken to overcome these challenges and gain better knowledge of crop dynamics. The arrival of cloud computing platforms such as Google Earth Engine (GEE) has enabled us to propose a Sentinel-2 (S2) phenology end-to-end processing chain. To achieve this, the following pipeline was implemented: (1) the building of hybrid Gaussian Process Regression (GPR) retrieval models of crop traits optimized with active learning, (2) implementation of these models on GEE (3) generation of spatiotemporally continuous maps and time series of these crop traits with the use of gap-filling through GPR fitting, and finally, (4) calculation of land surface phenology (LSP) metrics such as the start of season (SOS) or end of season (EOS). Overall, from good to high performance was achieved, in particular for the estimation of canopy-level traits such as leaf area index (LAI) and canopy chlorophyll content, with normalized root mean square errors (NRMSE) of 9% and 10%, respectively. By means of the GPR gap-filling time series of S2, entire tiles were reconstructed, and resulting maps were demonstrated over an agricultural area in Castile and Leon, Spain, where crop calendar data were available to assess the validity of LSP metrics derived from crop traits. In addition, phenology derived from the normalized difference vegetation index (NDVI) was used as reference. NDVI not only proved to be a robust indicator for the calculation of LSP metrics, but also served to demonstrate the good phenology quality of the quantitative trait products. Thanks to the GEE framework, the proposed workflow can be realized anywhere in the world and for any time window, thus representing a shift in the satellite data processing paradigm. We anticipate that the produced LSP metrics can provide meaningful insights into crop seasonal patterns in a changing environment that demands adaptive agricultural production.

Analysis of the main factors affecting mass production in the plastic molding process by using the finite element method

Plastic injection molding is widely used in many industrial applications. Plastic products are mostly used as disposable parts or as portable parts for fast replacements in many devices and machines. However, mass production is always adopted as an ideal method to cover the huge demands and customers’ needs. The problems of warpage due to thermal stresses, non-uniform pressure distribution around cavities, shrinkage, sticking and overall products quality are some of the important challenges. The main objective of this work is to analyze the stress distribution around the cavities during the molding and demolding to avoid their effects on the product quality. Moreover, diagnosing the critical pressure points around and overall the cavity projection area, which is subjected to high pressure will help to determine the optimum pressure distribution and ensure filling all cavities at the same time, which is another significant objective. Computer-aided design (CAD) and CATIA V5R20 are adopted for design and modeling procedures. The computer-aided engineering (CAE) commercial software ABAQUS 6141 has been dedicated as finite element simulation packages for the analysis of this process. Simulation results show that stress distribution over the cavities depends on both pressure and temperature gradient over the contact surfaces and can be considered as the main affecting factor. The acceptable ranges of the cavity stresses were determined according to the following values: the cavity and core region temperature of 55–65 °C, filling time of 10–20 s, ejection pressure 0.85 % of injection pressure, and holding time of 10–15 s. Also, theoretical results reveal that the uniform pressure and temperature distribution can be controlled by adjusting the cavities layout, runner, and gate size. Moreover, the simulation process shows that it is possible to facilitate and identify many difficulties during the process and modify the prototype to evaluate the overall manufacturability before further investing in tooling. Furthermore, it is also concluded that tooling iterations will be minimized according to the design of the selected process

NUMERICAL ANALYSIS OF INFUSION STRATEGIES IN VACUUM ASSISTED RESIN TRANSFER MOLDING (VARTM) PROCESS

The Liquid composite Molding (LCM) process, such as Vacuum Assisted Resin Transfer Molding (VARTM), offers a fast and high-quality production of composites laminates. In the VARTM process, the simulation tool is found beneficial to predict and solve composite manufacturing issues. The part quality is dependent on the resin mold filling stage in the VARTM process. The infiltration of resin into a porous fibrous medium is taken place during the resin mold filling stage. The permeability has a crucial role during the resin mold filling stage. In this study, simulation of resin infusion through multiple injection gates is discussed. The various infusion schemes are simulated to identify defect-free composite manufacturing. The simulation approach is applied to five different stacking sequences of reinforcements. In this transient simulation study, permeability and resin viscosity is essential inputs for the resin flow. The simulation approach found that a gating scheme plays a vital role in mold filling time and defect-free composite fabrication. It is found that the line gating system can be useful for fast mold filling over the point gating system.

Analytical and numerical analyses of filling progression and void formation in flip-chip underfill encapsulation process

Purpose This paper aims to study the filling progression of underfill flow and void formation during the flip-chip encapsulation process. Design/methodology/approach A new parameter of filling progression that relates volume fraction filled to filling displacement was formulated analytically. Another indicative parameter of filling efficiency was also introduced to quantify the voiding fraction in filling progression. Additionally, the underfill process on different flip-chips based on the past experiments was numerically simulated. Findings All findings were well-validated with reference to the past experimental results, in terms of quantitative filling progression and qualitative flow profiles. The volume fraction filled increases monotonically with the filling displacement and thus the filling time. As the underfill fluid advances, the size of the void decreases while the filling efficiency increases. Furthermore, the void formed during the underfilling flow stage was caused by the accelerated contact line jump at the bump entrance. Practical implications The filling progression enabled manufacturers to forecast the underfill flow front, as it advances through the flip-chip. Moreover, filling progression and filling efficiency could provide quantitative insights for the determination of void formations at any filling stages. The voiding formation mechanism enables the prompt formulation of countermeasures. Originality/value Both the filling progression and filling efficiency are new indicative parameters in quantifying the performance of the filling process while considering the reliability defects such as incomplete filling and voiding.

‘Making, Not Filling Time’

Improvisation and notation are frequently opposed in terms of transience versus permanence, an opposition that reflects broader Eurocentric ideas of orality and literacy. Confronting such binary distinctions, Schuiling describes the use of notation by three groups of improvising musicians, showing how notations mediate their understanding of time. This forms the basis of a critique of Alfred Schütz’s influential account of social interaction in musical performance. Schuiling argues that Schütz’s distinction of an ‘inner time’ of music and an ‘outer time’ mapped by the score remains tied to a work-centred musical ontology, and fails to attend to the making of time in the course of performance. Drawing on his fieldwork, Schuiling reconsiders the work of Maurice Halbwachs, the primary target of Schütz’s argument. Rather than understanding music as an object of inner contemplation, Halbwachs provides a view of music and temporality as a way of opening up to the world.

Increased Backward Wave Pressures Rather than Flow Explain Age-Dependent Heart Rate Effects on Central, But not Peripheral Arterial Pressure

Through both backward (Pb) and forward (Pf) wave effects, a lower heart rate (HR) associates with increased central (PPc), beyond brachial pulse pressure (PP). However, the relative contribution to Pf of aortic flow (Q) versus re-reflection of Pb, has not been determined. Using central pressure, aortic velocity and diameter measurements in the outflow tract (echocardiography), we constructed central pressure waveforms that account for the relative contribution of Q versus re-reflection to Pf. We thus evaluated the mechanisms of HR-PPc relations in a community sample (n=824) and the impact of age thereon. Inverse HR-PPc ( P <0.0001), but not HR-brachial PP ( P =0.064) relations were noted. The slope of HR-PPc relation was increased in older adults ( P <0.005). HR was inversely associated with ventricular filling time, ejection duration, stroke volume, and peak Pf ( P <0.001 to P <0.0001). However, an increased Q and hence pressures generated by the product of aortic characteristic impedance and Q did not account for Pf effects. Age-dependent HR-PPc and Pf relations were both accounted for by enhanced Pb ( P <0.0001) with an increased Pf mediated by increments in wave re-reflection ( P <0.0001). The lack of impact of ejection duration on PPc was explained by an increased time to peak Pb ( P <0.0001). In conclusion, increases in PPc and Pf at a decreased HR are accounted for by an enhanced Pb rather than by a prolonged ejection or filling duration and hence flow (Q). These effects at a young-to-middle age are of little clinical significance, but at an older age, are of clinical importance.

Multiple Responses Injection Moulding Parameter Optimisation Via Taguchi Method for Polypropylene-Nanoclay-Gigantochloa

Recently, the reinforcement of natural fibres into the polymer has been the main topic due to ecological which can sustain the life of our earth. Natural plant fibre composite has advantages in production in manufacturing product due to biodegradability and environmental protection. The injection moulding process is a major interest within the field of manufacturing technology because of the issue of archive the good quality of the product while minimizing the defect of the product that has been produced. Therefore, this research purpose describes the effects of gigantochloa scortechinii (natural fibre) mix with the polypropylene-nanoclay by using multiple objective optimisations for instance Taguchi Orthogonal Array method for injection moulding processing condition towards multiple responses such as melt flow index, flexural strength, warpage, and shrinkage. The compounding material used in this research is polypropylene, nanoclay, the compatibilizer which is polypropylene graft maleic anhydride (PP-g-MA), and gigantochloa scortechinii which known as bamboo fibre. For comparison purpose, the contents of natural fibre selected are 0wt.%, 3wt.% and 6wt.% towards the processing condition which are packing pressure, melt temperature, screw speed and filling time. Based on the signal to noise ratio analysis results, the highest value of S/NQP is at 6wt.% which is 160.6451 dBi followed by 3wt.% (158.1919 dBi) and 0wt.% (134.8150 dBi). Furthermore, the most influential parameter changed with the existence of Gigantochloa Scortechinii from melt temperature into packing pressure. In conclusion, the optimum values for multiple responses have been affected by the present of Gigantochloa Scortechinii.

762 Myocardial bridge evaluation towards personalized medicine (the rialto registry): preliminary findings

Aims Myocardial bridge (MB) is the most common inborn coronary artery variant in which a segment of an epicardial coronary artery takes a tunneled course under a bridge of myocardium. MB has been documented from 1.5% to 16% of invasive angiographic series thus the true prevalence of MB is uncertain. The clinical relevance of MB is heterogeneous, being usually an asymptomatic bystander. However, a growing body of evidence suggests its association with myocardial ischaemia. In the present work, by setting up a database of patients affected by MB, we sought to assess their clinical characteristics and risk of major adverse cardiac events (MACE). Methods and results This is a prospective/retrospective study and observational study in which we included 17 681 patients referred to undergo invasive coronary angiography (ICA) for suspected coronary artery disease. During the screening phase, we found that 338 cases (26 non-recruitable) were reported to have MB (1.9%). In-hospital clinical-instrumental data was acquired after ICA. The data obtained in the follow-up (FUP) visit is also included in the study. In particular, we recorded MACE and Seattle Angina Questionnaire (SAQ). The most frequent location of MB was the LAD coronary artery (96.8%). Other locations were the circumflex artery (1.3%), the right coronary artery (1%), the posterior interventricular artery (0.6%), and the first diagonal artery (0.3%). Chronic coronary syndrome (CCS) was the most frequent clinical presentation (47.5%). A big proportion (34.6%) of our patients were found to have MB during the occurrence of an acute coronary syndrome (ACS). In acute setting, unstable angina was the most frequent clinical presentation (17.6%). 47 patients (15%) underwent coronary angiography with provocative test (intracoronary acetylcholine) in order to search vasomotor disorders: according to COVADIS criteria, 17 procedures (5.5%) resulted positive for vasospastic angina (VSA). Invasive functional assessment with FFR/iFR was accomplished to assess the haemodynamic significance both of MBs and atherosclerotic plaques proximal to the MB segment in 35 patients (11.2%): in nine procedures (2.9%), functional tests resulted positive. β-Blockers (BBs) are suggested as first-line drugs as they increase diastolic filling time, by decreasing heart rate. Calcium channel blockers (CCBs) are useful, in VSA setting, to reduce epicardial spasm. In our court, 40% of patients toke BBs and 20% of patients toke CCBs at admission. The primary endpoint of the study is the incidence of MACE, defined as the composite of cardiac death, myocardial infarction and cardiac hospitalization. Considering patients who have already undergone FUP (114; 36.5%), we recorded 19 MACE (16.7% of patients with FUP). The secondary endpoint is the rate of patients with SAQ Angina Summary Score &lt; 70: the rate of patients with SAQ &lt; 70 is 23.7% at 6 months, 23.8% at 12 months and 23.2% at 24 months. Conclusions MB has been typically considered benign and asymptomatic, but its clinical relevance is still matter of debate. A remarkable proportion of our patients were found to have a MB during the occurrence of ACS or CCS, highlighting that different mechanisms of ischaemia may coexist. Furthermore, invasive functional assessment shows a plausible correlation between MB and vasomotor disorders. Our study is still ongoing, and we hope to maximize the data in order to have a solid comprehension of MB and to propose the assessment that may indicate a tailored therapy.

Reference values for fetal Doppler-based cardiocirculatory indices in monochorionic-diamniotic twin pregnancy

Background Placental anastomoses in monochorionic diamniotic (MCDA) twin pregnancy have a major impact on fetal circulation. This study was designed to define reference ranges of cardiac and vascular Doppler indices in MCDA twin pregnancies. Methods This cross-sectional study included 442 uncomplicated MCDA twin fetuses undergoing Doppler ultrasonography at 18–35 weeks of gestation. Left and right myocardial performance index (LV-MPI, RV-MPI), E/A ratio of atrioventricular valves, pulsatility indices of umbilical artery, middle cerebral artery (MCA), and ductus venosus (DV), cerebroplacental ratio, peak systolic velocity of MCA, S/a ratio of DV, and early diastolic filling time of ductus venosus (DV-E) were evaluated under standardized settings. The equation models between Doppler indices and gestational age (GA) were fitted. After adjustment for GA, the correlations between MPI and fetal heart rate (FHR), and between MPI and DV indices were analyzed. Results Estimated centiles of Doppler indices were derived as a function of GA, being distinct in values from those of singletons. There was no correlation between GA-adjusted MPI and FHR. DV-E was inversely related to LV-MPI. Conclusions MCDA twins showed significant changes in some Doppler indices throughout gestation with quantitative differences from singletons, emphasizing the importance of MC twin-specific reference values for clinical application. Further adjustment of MPI for FHR was unnecessary. DV-E is a vascular index indirectly representing fetal diastolic function.

Optimization of Injection-Molding Process for Thin-Walled Polypropylene Part Using Artificial Neural Network and Taguchi Techniques

Plastics are commonly used engineering materials, and the injection-molding process is well known as an efficient and economic manufacturing technique for producing plastic parts with various shapes and complex geometries. However, there are certain manufacturing defects related to the injection-molding process, such as short shot, shrinkage, and warpage. This research aims to find optimum process parameters for high-quality end products with minimum defect possibility. The Artificial Neural Network and Taguchi Techniques are used to find a set of optimal process parameters. The Analytic Hierarchy Process is used to calculate the weight of each defect in the proposed thin-walled part. The Finite Element Analysis (FEA) using SolidWorks plastics is used to simulate the injection-molding process for polypropylene parts and validate the proposed optimal set of process parameters. Results showed the best end-product quality was achieved at a filling time of 1 s, cooling time of 3 s, pressure-holding time of 3 s, and melt temperature of 230 °C. The end-product quality was mostly influenced by filling time, followed by the pressure-holding time. It was found that the margin of error for the proposed optimization methods was 1.5%, resulting from any uncontrollable parameters affecting the injection-molding process.