Alternative Parameter Research Articles

Estimation of Sea Spray Aerosol Surface Area Over the Southern Ocean Using Scattering Measurements

AbstractThis study focuses on methods to estimate dry marine aerosol surface area (SA) from bulk optical measurements. Aerosol SA is used in many models' ice nucleating particle (INP) parameterizations, as well as influencing particle light scattering, hygroscopic growth, and reactivity, but direct observations are scarce in the Southern Ocean (SO). Two campaigns jointly conducted in austral summer 2018 provided co‐located measurements of aerosol SA from particle size distributions and lidar to evaluate SA estimation methods in this region. Mie theory calculations based on measured size distributions were used to test a proposed approximation for dry aerosol SA, which relies on estimating effective scattering efficiency (Q) as a function of Ångström exponent (å). For distributions with dry å < 1, Q = 2 was found to be a good approximation within ±50%, but for distributions with dry å > 1, an assumption of Q = 3 as in some prior studies underestimates dry aerosol SA by a factor of 2 or more. We propose a new relationship between dry å and Q, which can be used for −0.2 < å < 2, and suggest å = 0.8 as the cutoff between primary and secondary marine aerosol‐dominated distributions. Application of a published methodology to retrieve dry marine aerosol SA from lidar extinction profiles overestimated aerosol SA by a factor of 3–5 during these campaigns. Using Microtops aerosol optical thickness measurements, we derive alternative lidar conversion parameters from our observations, applicable to marine aerosol over the SO.

The serum acetylcholinesterase (AChE) levels as an alternative diagnostic tool in pre-operative Hirschsprung's disease

Background: The golden standard of Hirschsprung's disease diagnosis is through a histopathological examination of the aganglionic site. The significance of serum acetylcholinesterase (AChE) immunohistochemistry for diagnosing Hirschsprung's disease has been widely accepted. However, the study of serum AChE levels in Hirschsprung's disease patients is still scarce. We aimed to examine the serum levels of AChE in individuals with Hirschsprung's disease. Methods: An analytical observational study with a cross sectional design was conducted on 29 patients with Hirschsprung's disease. We divided the patients into two groups: 14 in Hirschsprung's disease group and 15 in the control group. Serum AChE level was measured using the enzyme-linked immunosorbent assay (ELISA) method. The optimal cut-off value for detecting Hirschsprung’s disease was determined using the ROC analysis. Results: The prevalence of Hirschsprung was higher in males than in females. The average AChE level in the Hirschsprung group was 95.89 ± 51.11 Units/mL, while the average level of AChE in the control group was 44.45 ± 33.40 Units/mL. The optimal cut-off value was 46.615 Units/mL. We found that this study's sensitivity, specificity, positive predictive value, negative predictive value, and accuracy values ​​were 83.3%, 70.6%, 66.7%, 85.7%, and 75.9%, respectively. There was a significant relationship between serum AChE levels and Hirschsprung's disease (p=0.004). Conclusion: The AChE levels in blood serum can be used as an alternative diagnostic parameter for Hirschsprung's disease. Patients with Hirschsprung's disease had higher serum AChE levels than patients without Hirschsprung's disease.

How vector space models disambiguate adjectives: A perilous but valid enterprise

AbstractThe present study is part of a larger research project developing computational tools for large-scale corpus-based semantic analyses. One such tool represents semantic structure with vector space models (VSMs). The paper shows that this tool and the models built require a deeper understanding, especially with a view to how its results relate to cognitive theories of meaning. Although token-based VSMs are increasingly used in corpus-based cognitive semantics, we believe it is insufficiently appreciated how alternative parameter settings deal with a range of semantic issues, such as granularity of meaning, prototypicality of the domain of application and interaction with syntactic patterns. For the purpose of this paper, we will focus on only one of those issues, viz. the prototypicality of the domain of application, presenting the results of three of our case studies on the Dutch adjectivesheilzaam,hoekig,hachelijkandgeldig. The models presented are built from a 520MW corpus of contemporary Dutch and Flemish newspapers and by varying parameters such as window size, part-of-speech and frequency thresholds in the selection of features. The resulting VSMs are evaluated through visual analytics: although multidimensional, they can be reduced to 2D and represented in scatterplots where more similar tokens appear closer to each other. The color-coding with manual sense tags employed here makes it possible to compare the groupings provided by human annotators with those of the computational models in a way consistent with the cognitive approach to meaning and categorization.

Specificity of estimating femoral anteversion using linea aspera version for total hip arthroplasty: A three-dimensional computed tomography study.

Femoral anteversion is an important parameter that can prevent complication following total hip arthroplasty (THA) caused by improper positioning of the implant. However, assessing femoral anteversion can be challenging in situation with significant defect of the femoral neck. In this study, linea aspera version was nominated as alternative parameter to femoral anteversion. So, the main objective of this study is to determine whether femoral anteversion correlates with linea aspera version. Cross-sectional study. Three-dimensional images of 100 femora were generated and their femoral anteversion and linea aspera version was measured. Correlation between the parameters was calculated. The mean linea aspera version was 7.27° ± 12.17° (mean ± standard deviation) while the mean femoral anteversion was 11.84° ± 10.06°. The linea aspera version was inversely correlated with the femoral anteversion with a correlation coefficient of -0.85. Linea aspera should be considered as an additional bony landmark to assess proper implant positioning in THA.

Connected and disconnected sea partons from the CT18 parametrization of PDFs

The separation of the connected and disconnected sea partons, which were uncovered in the Euclidean path-integral formulation of the hadronic tensor, is accommodated with an alternative parametrization of the non-perturbative parton distribution functions in the CT18 global analysis. This is achieved with the help of the distinct small $x$ behaviours of these two sea partons and the constraint from the lattice calculation of the ratio of the strange momentum fraction to that of the $\bar u$ or $\bar d$ in the disconnected insertion. The whole dataset of CT18 is used in this CT18CS fit. The impact of the recent SeaQuest data on the $\bar{d}(x)-\bar{u}(x)$ distribution of CT18CS is also discussed. The separate momentum fractions for the valence, the connected sea and disconnected sea of $u$ and $d$, the strange and the gluon partons are presented at $\mu =1.3$ GeV for the first time. They can be compared term-by-term with systematic error controlled lattice calculations.

Impact of disturbance signatures on tree-ring width and blue intensity chronology structure and climatic signals in Carpathian Norway spruce

Tree radial growth is influenced by climatic and various non-climatic factors, which can complicate the extraction of climate signals from tree rings. We investigated the influence of disturbance on tree-ring width (RW) and latewood blue intensity (BI) chronologies of Norway spruce from the Carpathian Mountains to explore the extent to which disturbance can affect temperature signals in tree rings. Overall, ∼15000 high-elevation Norway spruce tree cores from 34 sites grouped into four regions (Slovakia, Ukraine, North and South Romania) were analyzed. The curve intervention detection (CID) method was applied to detect and correct identified disturbance trends. RW chronology structural comparisons were performed among disturbance-affected and disturbance-corrected chronologies for various spatial (regional / site) scales and sampling subsets. Structural comparisons were also performed for RW and BI chronologies developed from separate groups of series (i.e., disturbed, and undisturbed) for five sites exhibiting clear disturbance trends. Temperature sensitivity was assessed for all chronology variants of both parameters. We found that disturbance trends only affected RW chronologies at the site/subset scale with relatively small series replication and were not detected at the regional scale. Unlike RW, BI chronologies were generally unaffected by disturbance. BI data also contained much stronger growing season temperature signals, which appeared to be both spatially and temporally more coherent. Whereas highly replicated and spatially extensive datasets can help minimize or eliminate disturbance trends in RW chronologies, this potential influence should be considered when interpreting climatic signals in tree rings and reconstructing historical climate in weakly replicated periods. On the other hand, BI is a promising alternative tree ring parameter with stronger and more stable growing season temperature signals, whose seemingly disturbance-free chronology structure does not appear to suffer from this ecological bias, and therefore represents a more suitable parameter for dendroclimatological research.

Study on the coupling between engine and alternator in a free-piston Stirling generator

The free-piston Stirling generator (FPSG) is composed of a free-piston Stirling engine (FPSE) and a linear alternator. The coupling relationship between the two parts directly affects the FPSG’s performance. The published literature about simulation models mainly focuses on investigating the FPSE and the alternator separately, which could hardly show the coupling between them. From the perspective of acoustic impedance matching, this paper established a complete simulation model of the FPSG based on SAGE software. The coupling relationship between the engine and the alternator and the influence of some vital parameters on FPSG’s performance were systematically investigated. The results showed that the linear alternator parameters directly influence the acoustic impedance at the surface of the power piston facing the FPSE, thereby affecting the FPSG’s performance. The working pressure affects the linear alternator by changing the working frequency. The acoustic-to-electric efficiency is only determined by the linear alternator parameters, external load and working frequency. To verify the simulation model, a FPSG prototype was established. Its characteristics showed good agreement with the simulation. With the heating temperature of 610 ℃, it could output 1040 W electric power with a thermal-to-electric efficiency of 36.2 %.

Effectiveness of multi-physics numerical model in simulating accelerated corrosion with spatial and temporal non-uniformity

This study is motivated by the need to develop an efficient numerical model to simulate non-uniform interfacial degradation of reinforcing steel in concrete in an accelerated corrosion setup considering the influence of differential aeration, moisture and conductivity. In this study, a multi-physics finite element (FE) model is presented to simulate spatially and temporally non-uniform surface topography of corroding steel with rust layer, and eliminates the assumption of uniform mass loss and its linear variation with time as per available literature that uses classical approach of Faraday’s law. The model is validated experimentally with accelerated corrosion setup. Unlike previous studies, pore saturation (PS) is continuously monitored and its existing experimental correlations with conductivity and oxygen diffusivity are adopted so that the model can be extended to simulate natural corrosion to enhance the accuracy of service life predictions. These evaluations can be made completely nondestructive and in real-time eliminating the challenges in capturing the influence of environment by the use of alternative parameters such as relative humidity from real climate change predictions. The key findings from the investigation reveal that incorporating local environmental parameters measured in situ allows for the model to naturally evolve with anodic and cathodic locations on steel surface avoiding the need to assume predefined locations. It is envisioned that the developed multi-physics FE model can be used as a reliable substitute to accelerated corrosion experiment which is frequently used for durability studies of corroding reinforced concrete (RC) members. It is shown that the daily and cumulative mass loss evaluated from the degraded surface topography of the corroded rebar using the simulated model are in good agreement with those evaluated experimentally. Further, the maximum pit depth evaluated from the simulated surface is validated that has valuable applications in estimating degraded strength of corroding steel and service life of RC members.

Improved Oxygen Uptake Efficiency Parameters Are Not Correlated with VO2peak or Running Economy and Are Not Affected by Omega-3 Fatty Acid Supplementation in Endurance Runners.

Peak oxygen uptake (VO2peak) is one of the most reliable parameters of exercise capacity; however, maximum effort is required to achieve this. Therefore, alternative, and repeatable submaximal parameters, such as running economy (RE), are needed. Thus, we evaluated the suitability of oxygen uptake efficiency (OUE), oxygen uptake efficiency plateau (OUEP) and oxygen uptake efficiency at the ventilatory anaerobic threshold (OUE@VAT) as alternatives for VO2peak and RE. Moreover, we evaluated how these parameters are affected by endurance training and supplementation with omega-3 fatty acids. A total of 26 amateur male runners completed a 12-week endurance program combined with omega-3 fatty acid supplementation or medium-chain triglycerides as a placebo. Before and after the intervention, the participants were subjected to a treadmill test to determine VO2peak, RE, OUE, OUEP and OUE@VAT. Blood was collected at the same timepoints to determine eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in erythrocytes. OUE correlated moderately or weakly with VO2peak (R2 = 0.338, p = 0.002) and (R2 = 0.226, p = 0.014) before and after the intervention, respectively. There was a weak or no correlation between OUEP, OUE@VAT, VO2peak and RE despite steeper OUE, increased OUEP and OUE@VAT values in all participants. OUE parameters cannot be treated as alternative parameters for VO2peak or RE and did not show changes following supplementation with omega-3 fatty acids in male amateur endurance runners.

Compression Density as an Alternative to Identify an Optimal Moisture Content for High Shear Wet Granulation as an Initial Step for Spheronisation.

Pellet production is a multi-step manufacturing process comprising granulation, extrusion and spheronisation. The first step represents a critical control point, since the quality of the granule mass highly influences subsequent process steps and, consequently, the quality of final pellets. The most important parameter of wet granulation is the liquid requirement, which can often only be quantitatively evaluated after further process steps. To identify an alternative for optimal liquid requirements, experiments were conducted with a formulation based on lactose and microcrystalline cellulose. Granules were analyzed with a Powder Vertical Shear Rig. We identified the compression density (ρpress) as the said alternative, linking information from the powder material and the moisture content (R2 = 0.995). We used ρpress to successfully predict liquid requirements for unknown formulation compositions. By means of this prediction, pellets with high quality, regarding shape and size distribution, were produced by carrying out a multi-step manufacturing process. Furthermore, the applicability of ρpress as an alternative quality parameter to other placebo formulations and to formulations containing active pharmaceutical ingredients (APIs) was demonstrated.

Estimation of Site Terms in Ground-Motion Models for California Using Horizontal-to-Vertical Spectral Ratios from Microtremor

ABSTRACT The horizontal-to-vertical spectral ratios from microtremor (mHVSR) data obtained at 196 seismic stations in California are used to evaluate three alternative microtremor-based proxies for site amplification for use in ground-motion models (GMMs): the site fundamental period (f0), the period-dependent amplitude of the mHVSR(T), and the normalized amplitude of the mHVSR(T). The alternative parameters are evaluated for the sites with and without measurements of VS30. If a VS30 measurement is not available for a site, then f0 has the highest correlation with the site amplification for short periods (T <1 s) and the normalized amplitude of the mHVSR(T) has the highest correlation for long periods (T ≥1 s). If a measurement of the VS30 is available for a site, then the normalized amplitude of the mHVSR(T) has the highest correlation for the site amplification not explained by VS30 for all periods. For both cases, the correlations are strongest at the longer periods as mHVSR(T) measurements excel at providing valuable information for sites with long-period amplification due to the deeper velocity structure. In particular, for sites with a VS30 measurement, the normalized mHVSR(T) amplitude provides more information about the long-period site terms than the basin depth currently used in GMMs. Empirical models of the median and standard deviation of the site terms based on the normalized mHVSR(T) curves are developed for the two cases. These models can be used directly in the ASK14 GMM to modify the median and aleatory standard deviation or they can be used to estimate the site-specific site term in the context of a partially nonergodic GMM. Including the mHVSR(T) measurement can have a significant effect on estimates of the ground motion at a site: the range 5%–95% on the observed HVSR(T) values corresponds to factors of 0.6–1.6 for the median spectral acceleration for periods between 0.5 and 4 s.

A NMR hybrid J-coupling alternation (hJCA) parameter linearly correlated to properties of intermolecular H-bonded chains

Intermolecular H-bonds play a fundamental role for macromolecules in biochemistry. In this sense, the analysis of NMR scalar couplings across H-bonded chains has emerged as an important method to unveil the quasi-covalent character of the so-called intermolecular self-assembly. To investigate relationships between these couplings and molecular properties of H-bonded chains, we propose a hybrid J-coupling alternation (hJCA) parameter. Our definition involves intra and intermolecular hyperfine contributions useful for chains with different parities. The results for increasing (HCN)n (n = 4–13) chains give evidence of linear correlations between hJCA and other molecular properties. For example, hJCA exhibits a linear correlation with the energy gap for these chains, which may be attributable to a possible degree of hyperconjugation of hydrogen bonding in HCN chains.

A fuel-consumption based window method for PEMS NOx emission calculation of heavy-duty diesel vehicles: Method description and case demonstration

Due to the lack of engine reference torque and the accumulated work of reference transient cycle, the work based window (WBW) method for portable emission measurement system test data processing cannot be used for vehicle emission assessment in the current on-board diagnostics (OBD) system in China. In this work, a fuel-consumption based window (FBW) method was proposed to imitate a WBW method procedure by using fuel consumption rate as an alternative parameter to scale the window so the entire procedure can be based on the attainable data items in the OBD system. Some key issues regarding converting WBW method to FBW method, including window separation, window average power ratio calculation and specific NOx emission conversion from mg/kg. fuel to mg/kW.h, were solved by linking the 100-km fuel consumption and the average vehicle specific power of China World Transient Vehicle Cycle test. The comparison between the FBW and WBW methods on the NOx emission calculation results shows that the number of all windows, the number of valid windows, and the thresholds for >50% valid windows are quite similar for WBW and FBW methods. The estimation accuracy of average power ratio for the FBW method depends on the value of transmission efficiency of vehicle driveline. The deviations of 90% specific NOx emission in mg/kW.h between the two methods are smaller than 6% for the cases investigated in the present work.

Rapid eye movement sleep duration during the multiple sleep latency test to diagnose hypocretin-deficient narcolepsy.

To assess the performances of alternative measures of the multiple sleep latency test (MSLT) to identify hypocretin-deficiency in patients with a complaint of hypersomnolence, including patients with narcolepsy. MSLT parameters from 374 drug-free patients with hypersomnolence, with complete clinical and polysomnographic (PSG) assessment and cerebrospinal hypocretin-1 measurement were collected. Conventional (sleep latency, number of sleep onset REM-SOREM-periods) and alternative (sleep duration, REM sleep latency and duration, sleep stage transitions) MSLT measures were compared as function of hypocretin-1 levels (≤110 vs > 110 pg/mL). We performed receiver-operating characteristics analyses to determine the best thresholds of MSLT parameters to identify hypocretin-deficiency in the global population and in subgroups of patients with narcolepsy (i.e. typical cataplexy and/or positive PSG/MSLT criteria, n = 223). Patients with hypocretin-deficiency had shorter mean sleep and REM sleep latencies, longer mean sleep and REM sleep durations and more direct REM sleep transitions during the MSLT. The current standards of MSLT/PSG criteria identified hypocretin-deficient patients with a sensitivity of 0.87 and a specificity of 0.69, and 0.81/0.99 when combined with cataplexy. A mean REM sleep duration ≥ 4.1 min best identified hypocretin-deficiency in patients with hypersomnolence (AUC = 0.932, sensitivity 0.87, specificity 0.86) and ≥ 5.7 min in patients with narcolepsy (AUC = 0.832, sensitivity 0.77, specificity 0.82). Compared to the current neurophysiological standard criteria, alternative MSLT parameters would better identify hypocretin-deficiency among patients with hypersomnolence and those with narcolepsy. We highlighted daytime REM sleep duration as a relevant neurophysiological biomarker of hypocretin-deficiency to be used in clinical and research settings.

(Invited) Achieving Lower Power Logic Using P-Type Metal Oxide Thin Film Transistors

Thin film transistors (TFTs) have enabled the active matrix displays that are a ubiquitous part of everyday life, from mobile phones and tablets through to desktop monitors and home televisions. They are used in the circuit at each pixel over the display as they can be fabricated for relatively low cost with excellent uniformity at low temperatures over large areas on glass substrates. These pixel circuits only require either n-channel or p-channel enhancement mode TFTs. However, there has long been a desire to integrate the display driver electronics onto the display panel as an alternative to connecting silicon-based integrated circuits using complementary metal oxide semiconductor (CMOS) field effect transistors (FETs) to displays. More recently, there has been an increasing interest in producing other logic circuits using TFTs on glass and plastic substrates as this could enable a new generation of products with embedded electronics. However, both of these applications need low power logic circuits. CMOS is an inherently low power technology, but it requires both n-channel and p-channel transistors. Whilst this can be realised in silicon CMOS FETs, it has not yet been achieved using TFTs because it has proved difficult to realise both n-channel and p-channel devices using one material system at low cost. For example, hydrogenated amorphous silicon can be used to make reasonable n-type material but not p-type.Thin film oxide semiconductors such as amorphous indium gallium zinc oxide have been successfully commercialised in the pixel circuits of active matrix displays as they possess high field effect mobility, low threshold voltage, low off-state current and a high switching ratio. There is therefore a lot of interest in finding a suitable complementary p-type metal oxide thin film material to allow CMOS-type logic to be realised using this material system.Cuprous oxide is one such promising candidate material as the top of the valence band is dominated by states which form as a result of hybridisation of the completely filled Cu 3d orbitals and the O 2p orbitals. These hybridised states are less localised and have a higher dispersion with a resulting decrease in the effective mass of holes in these states and a higher carrier mobility. The results of an extensive study of this material shows that the grain structure is of critical importance with [100] oriented films resulting in a higher mobility. Furthermore, the impact of grain boundaries on conduction must be controlled. Although this allows TFTs with reasonable on-state current to be fabricated, it is found that there is a significant residual off-state current which is a result of electron accumulation in the channel. This is consistent with the high off-state current that has been observed widely in TFTs using p-type metal oxide thin film materials.The low off-state current in silicon MOSFETs means that the geometric transistor design in low power CMOS logic circuits only needs to focus on the effect of the on-state current in the p-channel and n-channel transistors. However, in TFTs, the much larger off-state current also becomes important as it can end up being a significant parameter when calculating the power consumption of CMOS logic circuits. An alternative geometric design parameter for TFT logic circuits is presented. This compares the maximum switching current with the static currents allowing optimisation based on both the noise margin and static power consumption. The result is improved performance of TFT-based CMOS logic circuits using the n- and p-type thin film oxide semiconductors that are currently available.

Forest road density in flat and sloping site conditions in Brazil

ABSTRACT Forest road densities which are too high increase production costs, planting area loss, and environmental impacts. To solve this problem and plan an adequate forest road density, it is necessary to analyze and consider the topography, road network-related costs, and the type and number of machines to meet the required wood production. The aim of this study was to determine the current road density (RD), the optimal economic road density (ORD) and operational road density (OD) in flat and sloping site conditions for the full tree harvesting system in Southern Brazil. The RD was determined by the ratio of total road lengthand the total productive area. ORD was determined based on the transport geometry model, considering the minimization of the sum of unit costs of road construction and maintenance, loss of productive area, mitigation of road impacts, and wood extraction. The OD was determined considering the minimum number of extraction machines necessary to meet the annual demand for wood. All forest road densities were lower in flat site conditions than in sloping areas. In both conditions (flat and sloping), RDs (126 and 180 m ha−1, respectively) were higher than ORDs (53 and 65 m ha−1, respectively), which were lower than ODs (92 and 123 m ha−1, respectively). Therefore, OD can be an alternative parameter for managers to use in forest road network planning, mainly in conditions where ORD is not feasible to adopt.

Is pulmonary artery wedge pressure a reliable surrogate of left ventricular end-diastolic pressure during exercise for diagnosing HFpEF in patients with unexplained dyspnea?

Abstract Background Left ventricular end-diastolic pressure (LVEDP) is the gold-standard for the assessment of LV filling pressure. For practical reasons, pulmonary artery wedge pressure (PAWP) is used as a surrogate for LVEDP. However, the interposition of the left atrium (LA) may account discrepancies between LVEDP and PAWP. The imprecision of both end-diastolic (or mid-A) and mean PAWP estimates for LVEDP has been widely described for cardiac catheterization at rest. PAWP measurement during exercise has been advocated to discriminate heart failure with preserved ejection fraction (HFpEF) from non-cardiac dyspnea, with an end-expiratory pathologic threshold ≥25 mmHg. However, a formal comparison of PAWP (either mid-A or mean PAWP) vs LVEDP during exercise has never been performed. Aim To compare LVEDP and PAWP during exercise. Methods We retrospectively analyzed consecutive patients with unexplained dyspnea and a normal LV ejection fraction, who had a clinical indication of right and left heart catheterization at rest and during exercise to assess unexplained dyspnea. Patients with mitral regurgitation ≥ moderate were excluded. Hemodynamic measurements were always taken at end-expiration. Results Forty-six consecutive patients were included in the analysis (80% with a peak mean PAWP ≥25 mmHg). We found a good correlation between both mid-A and mean PAWP on one side, and LVEDP on the other side (R2>0.55). At peak exercise, mid-A PAWP had no bias as compared with LVEDP, while mean PAWP slightly overestimated LVEDP by 1–2 mmHg. However, confidence intervals were quite large (Figure 1), suggesting imprecision of PAWP estimates for LVEDP in the individual patient. A disagreement between mean PAWP and LVEDP, using a threshold of ≥25 mmHg for both variables at peak exercise, was found in 11% of patients. In 4% of them, mean PAWP was ≥25 but LVEDP <25 mmHg, due to the appearance of tall V waves in the PAWP position (LA stiffness), increasing PAWP above LVEDP. In the remaining 7%, LVEDP was ≥25 but PAWP <25 mmHg. The latter patients, in whom HFpEF would have not been diagnosed based on peak PAWP alone, showed a PAWP increase during exercise relative to cardiac output changes (PAWP/CO slope) >2 mmHg/L/min, as an alternative parameter suggesting HFpEF. Conclusions In patients with unexplained exertional breathlessness, both mid-A and mean PAWP showed good correlation with LVEDP during exercise with minimal average bias, but their ability to estimate LVEDP was burdened by a relevant imprecision. Therefore, when in these patients peak PAWP is <25 mmHg, its assessment might need to be complemented by additional measurements (including LVEDP or PAWP/CO slope) to maximize the diagnostic power of exercise cardiac catheterization in identifying HFpEF. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship.

Application of machine learning in predicting the rate-dependent compressive strength of rocks

Accurate prediction of compressive strength of rocks relies on the rate-dependent behaviors of rocks, and correlation among the geometrical, physical, and mechanical properties of rocks. However, these properties may not be easy to control in laboratory experiments, particularly in dynamic compression experiments. By training three machine learning models based on the support vector machine (SVM), back-propagation neural network (BPNN), and random forest (RF) algorithms, we isolated different input parameters, such as static compressive strength, P-wave velocity, specimen dimension, grain size, bulk density, and strain rate, to identify their importance in the strength prediction. Our results demonstrated that the RF algorithm shows a better performance than the other two algorithms. The strain rate is a key input parameter influencing the performance of these models, while the others (e.g. static compressive strength and P-wave velocity) are less important as their roles can be compensated by alternative parameters. The results also revealed that the effect of specimen dimension on the rock strength can be overshadowed at high strain rates, while the effect on the dynamic increase factor (i.e. the ratio of dynamic to static compressive strength) becomes significant. The dynamic increase factors for different specimen dimensions bifurcate when the strain rate reaches a relatively high value, a clue to improve our understanding of the transitional behaviors of rocks from low to high strain rates.

Minimum f-Divergence Estimation With Applications to Degradation Data Analysis

Minimizing the divergence between two probability distributions offers an alternative parameter estimation method. The current literature mainly focuses on minimizing the Kullback-Leibler (K-L) divergence between the true and the proposed models in which the true model is assumed to be known or fixed. In this paper, we propose a parameter estimation method that minimizes the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$f$ </tex-math></inline-formula> -divergence between two probability distributions. The method is suitable for different situations, no matter the true distribution is known or not. The statistical properties of the estimator, including consistency and asymptotic normality, are established. As an illustration, our method is employed to estimate the degradation model, which is a model frequently used to assess the lifetime of highly reliable products. A simulation study and a real degradation data analysis are presented to illustrate the effectiveness of the proposed estimation method.

Tight Bound on NewHope Failure Probability

<monospace>NewHope</monospace> Key Encapsulation Mechanism (KEM) has been presented at USENIX 2016 by Alkim <i>et al.</i> and was one of the lattice-based candidates to the post-quantum standardization initiated by the NIST. However, despite the relative simplicity of the protocol, the bound on the decapsulation failure probability resulting from the original analysis is not tight. In this work we refine this analysis to get a tight upper-bound on this probability which happens to be much lower than what was originally evaluated. As a consequence, we propose a set of alternative parameters, increasing the security and the compactness of the scheme. However using a smaller modulus prevent the use of a full NTT algorithm to perform multiplications of elements in dimension 512 or 1024. Nonetheless, similarly to previous works, we combine different multiplication algorithms and show that our new parameters are competitive on a constant time vectorized implementation. Our most compact parameters bring a speed-up of <inline-formula><tex-math notation="LaTeX">$17\%$</tex-math></inline-formula> (resp. <inline-formula><tex-math notation="LaTeX">$11\%$</tex-math></inline-formula> ) in performance but allow to gain more than <inline-formula><tex-math notation="LaTeX">$19\%$</tex-math></inline-formula> over the bandwidth requirements and to increase the security of <inline-formula><tex-math notation="LaTeX">$10\%$</tex-math></inline-formula> (resp. <inline-formula><tex-math notation="LaTeX">$7\%$</tex-math></inline-formula> ) in dimension 512 (resp. 1024).