Simple Estimation Research Articles

Extension of Simple and Accurate Inductance Estimation for Rectangular Planar Windings

This paper proposes a method to generalize the equations estimating the inductance of square-shape planar windings to rectangle shape. This is done by utilizing the optimal <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$p$</tex-math></inline-formula> -norm of the Generalized Mean Value or Power Mean (PM). Three well-established equations with verified accuracy are examined, namely Wheeler's, Rosa's, and the Monomial, which by definition consider only regular polygons. One critical parameter of the original equations is the outer-side length of the winding, which for the rectangle case, can be substituted by the PM of the two outer-side lengths, without the need for any further modifications. A methodology to select the optimal <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$p$</tex-math></inline-formula> -norm for the PM is presented in terms of achieving the best accuracy for this estimation. The selection of the optimal <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$p$</tex-math></inline-formula> is based on results from datasets containing more than 2600 simulations of different rectangle-shaped windings. Finally, the estimation accuracy is verified by laboratory measurements for a selection of planar inductors.

Structure of the equivalent Newtonian systems in MONDN-body simulations

Aims.We investigate the core-cusp problem of the Λ cold dark matter (ΛCDM) scenario in the context of the modified Newtonian dynamics (MOND) paradigm while exploiting the concept of an equivalent Newtonian system (ENS).Methods.By means of particle-meshN-body simulations in MOND, we explored the processes of galaxy formation via cold dissipationless collapse and the merging of smaller substructures. From the end states of our simulations, we recovered the associated ENS and studied the properties of their dark matter halos. We compared the simulation results with simple analytical estimates with a family ofγ-models.Results.We find that the dark matter density of ENSs of most spherical cold collapses have a markedly cored structure, particularly for the lowest values of the initial virial ratios. End states of some simulations with initially clumpy conditions have more complex profiles, and some of their ENSs exhibit a moderate cusp, with the logarithmic density slope always shallower than one.Conclusions.In contrast to what one would expect from theoretical and numerical arguments in ΛCDM, these results seem to point towards the fact that the absence of a central DM cusp in most observed galaxies would be totally consistent in a MONDian description.

Uncertainty and bias in fragility estimates by intensifying artificial accelerations

To comply with the objectives of Performance-Based Earthquake Engineering and gain a comprehensive understanding of a structure’s seismic response, the utilization of multiple ground motion records selected or scaled at various hazard levels is often necessary. Incremental Dynamic Analysis (IDA) and cloud analysis methods represent wide-range probabilistic approaches employed for this purpose. However, due to their computational complexity, researchers and engineers have sought alternative solutions. One such solution is the application of intensifying artificial accelerations (IAAs). By employing IAAs, the structural response can be recorded from linear elastic to nonlinear, and ultimately up to the collapse capacity, all within a single simulation.This paper presents a comprehensive summary of various generations of IAAs and their unique characteristics. To assess their performance on nonlinear single degree-of-freedom systems, the IAAs are compared against IDA results. As IAAs are typically generated to be independent of specific hazard levels, a series of generic (i.e., standardized) ground motion sets are used for IDA. Our objective is to quantitatively evaluate the bias in the mean response estimation by employing different generations of IAAs, developed based on various base response spectra and optimization objectives. Additionally, this paper provides a simplified estimation of fragility curves based on IAAs, and compares the resulting uncertainty with those generated through IDA. The findings aim to enhance the understanding of IAAs’ capabilities and limitations in capturing the seismic response characteristics of structures.

Effect of oil price shocks on output and prices: evidence from Saudi Arabia.

The primary objective of this article is to estimate how the spike in oil prices has impacted Saudi Arabia's output and other macroeconomic indicators. To address this question, the study utilizes a simple VAR estimation and VAR estimation with sign restrictions, specifically an oil demand shock and an oil supply shock, to determine the influence of oil price shocks. The study's findings are consistent with conventional wisdom and current research from oil-exporting countries. Consistent with all model specifications for both periods (monthly 2010q1 to 2020q2 and quarterly 1996q1 to 2020q2), the study finds that an oil price shock benefits the Saudi Arabian economy. The results indicate that a 10% increase in oil prices leads to a 2% increase in output, a 0.15 percentage point increase in the consumer price index, a 6% increase in export value, and a 3% increase in import value. The study highlights the importance of considering both oil supply and demand shocks in analyzing the impact of oil price fluctuations and concludes that the demand shock is more influential than the supply shock.

Rocking stiffness of electrical cabinets with tubular base in nuclear power plants

Safe operation of nuclear power plants during an earthquake requires continued operation of safety related electrical equipment as intended. Such equipment are mounted in electrical cabinets and are seismically qualified by using an in-cabinet response spectra (ICRS). Generation of ICRS requires a good understanding of the cabinet’s dynamic characteristics. Past studies have shown that the rotational stiffness associated with the cabinet base and the mounting arrangement plays a primary role in the dynamic behavior of the cabinet. This rotational stiffness is needed to evaluate and characterize the global rocking mode of cabinet vibration. Existing studies have developed formulations to calculate the rocking stiffness for a few mounting arrangements that are typically found in United States and some other western countries. However, existing formulations could not be applied to cabinets in South Korean nuclear plants due to the differences in cabinet mounting type. This study is focused on consideration of tubular mounting arrangement that is typically found in South Korean plants. First, closed-form formulations are developed using fundamental principles of mechanics for two separate cases of this mounting arrangement. Then, detailed nonlinear finite element (FE) analyses are conducted for different mounting arrangements corresponding to different properties and dimensions of the tubular base. The FE models are used to calibrate the proposed closed-form formulations for various different configurations and structural or geometrical properties of tubular members. The proposed formulations provide a simple and accurate estimation of cabinet rocking stiffness which otherwise is difficult to evaluate without a shake table test or a detailed finite element analysis.

Parameters of the Liquid-Gas-State Triangle for Hard-Core Attractive Yukawa Fluids.

We discuss the triangle of the liquid-gas concept within the fluid-lattice gas isomorphism approach and the Zeno-element, taking the hard-core Yukawa fluid (HCAYF) as an example. The applicability of such an isomorphism is demonstrated by the symmetrization of binodals with mapping onto the Ising model coexistence curve. We show that the parameters of the isomorphism transformation reflect the liquid-phase instability for hard-core Yukawa potential and its generalization. We also provide a simple mean-field estimate for the parameter z of the fluid-lattice gas transformation and use it to obtain the locus of the critical point.

A simple nonparametric conditional quantile estimator for time series with thin tails

In this study, we consider a simple conditional quantile estimator in a nonparametric framework with time series data. We prove the consistency and asymptotic normality of our simple estimator for absolutely regular processes (β-mixing). This simple estimator can get better finite sample performances at thin tails than the check-function-based estimator. Finite sample simulation results show that our simple estimators have better finite sample performances at thin tails of time series data.

Toward a simple and accurate Lagrangian-based error estimator for the BDF algorithms and adaptive time-stepping

PurposeThe purpose of this paper is to design a simple and accurate a-posteriori Lagrangian-based error estimator is developed for the class of backward differentiation formula (BDF) algorithms with variable time step size, and the adaptive time-stepping in BDF algorithms is demonstrated for efficient time-dependent simulations in fluid flow and heat transfer.Design/methodology/approachThe Lagrange interpolation polynomial is used to predict the time derivative, and then the accurate primary result is obtained by the Gauss integral, which is applied to evaluate the local error. Not only the generalized formula of the proposed error estimator is presented but also the specific expression for the widely applied BDF1/2/3 is illustrated. Two essential executable MATLAB functions to implement the proposed error estimator are appended for practical applications. Then, the adaptive time-stepping is demonstrated based on the newly proposed error estimator for BDF algorithms.FindingsThe validation tests show that the newly proposed error estimator is accurate such that the effectivity index is always close to unity for both linear and nonlinear problems, and it avoids under/overestimation of the exact local error. The applications for fluid dynamics and coupled fluid flow and heat transfer problems depict the advantage of adaptive time-stepping based on the proposed error estimator for time-dependent simulations.Originality/valueIn contrast to existing error estimators for BDF algorithms, the present work is more accurate for the local error estimation, and it can be readily extended to practical applications in engineering with a few changes to existing codes, contributing to efficient time-dependent simulations in fluid flow and heat transfer.

Comparison of known spawner abundance from fence counts to visual counts for simplified spawner estimation methods

Many salmon species are monitored by visual counts of spawners in streams; however, there are few data sets where abundance is known and compared to estimates derived from visual counts. We used spawner fences to obtain known kokanee ( Oncorhynchus nerka) spawner abundance (14 stream-years) on streams that are monitored with annual visual surveys (7 to 9 counts per year) and incorporated similar published data from pink salmon ( Oncorhynchus gorbuscha) (11 stream-years). We investigated the performance of several simplified expansion factor estimation methods with survey life and observer efficiency as unknown nuisance parameters. All visual indices of kokanee and pink salmon spawners from live ground counts were highly correlated to abundance from fence counts ( r2 ≥ 0.96 and 0.89, respectively). Application of cross-validation on out-of-sample data for both species showed that mean% error could range from 13% to 53% on a previously unsampled stream depending on the species, counting method, and visual index used. Predictive performance metrics were less sensitive to counting frequency than observer efficiency and associated variability, which was influenced by the counting method (aerial versus ground surveys).

Survival and Response Outcomes for Gastrointestinal Neuroendocrine Tumor (GEP-NETs) Patients Treated with Lutetium-177-DOTATATE in a Brazilian Reference Center: A Six-Year Follow-Up Experience.

PRRT can be an option for all-grade GEP-NETs, but selecting patients is challenging. In this scenario, clinical-pathological and radiological characteristics, such as pre-treatment Ga-68 DOTA PET/CT, might have the potential to help. A retrospective chart review was conducted on advanced GEP-NETs treated with at least one PRRT dose. Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan-Meier method. Krenning Score (KS), and the maximum standardized uptake value (SUVmax) were derived from the pre-treatment scans. A maximally selected rank statistics test was used for SUVmax simple cut point estimate. Among 36 patients, 19 had primary pancreatic tumors. The numbers of G1, G2, and G3 tumors were 10, 18, and 7, respectively. During a median follow-up of 90.5 months, 4 patients died. Median OS was not reached for G1 and G2 tumors, and it was 30 months for G3 (p = 0.001). Median PFS was 23 months, with G3 showing lower PFS compared to G1 [7 versus 30 months; HR 8.41 (95%CI 2.2-31.0; p = 0.001)]. PRRT provides long-term PFS in patients with G1/G2 GEP-NETs independent of clinical characteristics and primary site. G3 has worse survival, but selected patients may experience long OS after PRRT treatment.

Integrating spatial and ecological information into comprehensive biodiversity monitoring on agricultural land

Biodiversity loss on agricultural land is a major concern. Comprehensive monitoring is needed to quantify the ongoing changes and assess the effectiveness of agri-environmental measures. However, current approaches to monitoring biodiversity on agricultural land are limited in their ability to capture the complex pattern of species and habitats. Using a real-world example of plant and habitat monitoring on Swiss agricultural land, we show how meaningful and efficient sampling can be achieved at the relevant scales. The multi-stage sampling design of this approach uses unequal probability sampling in combination with intermediate small-scale habitat sampling to ensure broad representation of regions, landscape types, and plant species. To achieve broad coverage of temporary agri-environmental measures, the baseline survey on permanent plots is complemented by dynamic sampling of these specific areas. Sampling efficiency and practicality are ensured at all stages of sampling through modern sampling techniques, such as unequal probability sampling with fixed sample size, self-weighting, spatial spreading, balancing on additional information, and stratified balancing. In this way, the samples are well distributed across ecological and geographic space. Despite the high complexity of the sampling design, simple estimators are provided. The effects of stratified balancing and clustering of samples are demonstrated in Monte Carlo simulations using modelled habitat data. A power analysis based on actual survey data is also presented. Overall, the study could serve as a useful example for improving future biodiversity monitoring networks on agricultural land at multiple scales.

An Ecofriendly Novel Spectrophotometric Estimation and Validation of Meloxicam in Bulk Drug and their Dosage Form by mixed Hydrotropic Solubilization Method

Solubility is a crucial factor during estimation of poorly soluble drugs. Literature survey reveals spectrophotometric estimation of poorly soluble drugs are mostly done by employing organic solvents. The drawbacks of organic solvents include higher cost, toxicity, pollution and error due to volatility. Hydrotropic solubilisation method involves increasing the solubility of a poorly soluble drug in water with the addition of hydrotropic agents. Most of NSAIDs like Meloxicam, Mefenamic acid, Aceclofenacetc are poorly soluble in water. Meloxicam was found to be soluble in mixed hydrotropic solution of 10% sodium benzoate and 10% sodium caprylate with maximum absorbance at 364 nm. The developed method was found to be linear in the range of 2-10 µg/ml with correlation coefficient (R2) of 0.9968. The LOD and LOQ of proposed method was found to be 0.2634 µg/ml and 0.7983 µg/ml respectively. A novel, simple, safe, sensitive and cost-effective spectrophotometric estimation method was developed for estimation of Meloxicam using 10% sodium benzoate and 10% sodium caprylate as hydrotropic agent. This solubilization method can be employed to preclude the use of organic solvents for the estimation of poorly soluble drugs.

Tracing the opposing assimilate and nutrient flows in live conifer needles.

The vasculature along conifer needles is fundamentally different from that in angiosperm leaves as it contains a unique transfusion tissue inside the bundle sheath. In this study, we used specific tracers to identify the pathway of photoassimilates from mesophyll to phloem, and the opposing pathway of nutrients from xylem to mesophyll. For symplasmic transport we applied esculin to the tip of attached pine needles and followed its movement down the phloem. For apoplasmic transport we let detached needles take up a membrane-impermeable contrast agent and used micro-X-ray computed tomography to map critical water exchange interfaces and domain borders. Microscopy and segmentation of the X-ray data enabled us to render and quantify the functional 3D structure of the water-filled apoplasm and the complementary symplasmic domain. The transfusion tracheid system formed a sponge-like apoplasmic domain that was blocked at the bundle sheath. Transfusion parenchyma cell chains bridged this domain as tortuous symplasmic pathways with strong local anisotropy which, as evidenced by the accumulation of esculin, pointed to the phloem flanks as the preferred phloem-loading path. Simple estimates supported a pivotal role of the bundle sheath, showing that a bidirectional movement of nutrient ions and assimilates is feasible and emphasizing the role of the bundle sheath in nutrient and assimilate exchange.

Low-Cycle Fatigue Behavior of Wire and Arc Additively Manufactured Ti-6Al-4V Material.

Additive manufacturing (AM) techniques, such as wire arc additive manufacturing (WAAM), offer unique advantages in producing large, complex structures with reduced lead time and material waste. However, their application in fatigue-critical applications requires a thorough understanding of the material properties and behavior. Due to the layered nature of the manufacturing process, WAAM structures have different microstructures and mechanical properties compared to their substrate counterparts. This study investigated the mechanical behavior and fatigue performance of Ti-6Al-4V fabricated using WAAM compared to the substrate material. Tensile and low-cycle fatigue (LCF) tests were conducted on both materials, and the microstructure was analyzed using optical microscopy and scanning electron microscopy (SEM). The results showed that the WAAM material has a coarser and more heterogeneous grain structure, an increased amount of defects, and lower ultimate tensile strength and smaller elongation at fracture. Furthermore, strain-controlled LCF tests revealed a lower fatigue strength of the WAAM material compared to the substrate, with crack initiation occurring at pores in the specimen rather than microstructural features. Experimental data were used to fit the Ramberg-Osgood model for cyclic deformation behavior and the Manson-Coffin-Basquin model for strain-life curves. The fitted models were subsequently used to compare the two material conditions with other AM processes. In general, the quasi-static properties of WAAM material were found to be lower than those of powder-based processes like selective laser melting or electron beam melting due to smaller cooling rates within the WAAM process. Finally, two simplified estimation models for the strain-life relationship were compared to the experimentally fitted Manson-Coffin-Basquin parameters. The results showed that the simple "universal material law" is applicable and can be used for a quick and simple estimation of the material behavior in cyclic loading conditions. Overall, this study highlights the importance of understanding the mechanical behavior and fatigue performance of WAAM structures compared to their substrate counterparts, as well as the need for further research to improve the understanding of the effects of WAAM process parameters on the mechanical properties and fatigue performance of the fabricated structures.

Simple correlation dimension estimator and its use to detect causality

Revisiting the Grassberger–Procaccia algorithm inspires us to introduce an extremely simple estimator of the correlation dimension. For the new estimator, we also provide guidance on determining the extent to which the correlation dimension may be underestimated, given the size of the data and the dimensionality of the state space.As a topical application, the new estimates, along with some established intrinsic dimension calculations, are used to detect causal relationships. For the demonstration, we use a challenging example of coupled chaotic oscillators.

On general weighted cumulative residual extropy and general weighted negative cumulative extropy

In this paper, we define general weighted cumulative residual extropy (GWCRJ) and general weighted negative cumulative extropy (GWNCJ). We obtain simple estimators for complete and right censored data. We obtain some results on GWCRJ and GWNCJ. We establish its connection to reliability theory and coherent systems. We also propose empirical estimators of GWNCJ. GWCRJ based on first-order statistics has been studied. Proposed estimators are calculated through data analysis. A new test of uniformity is proposed and analysed based on GWNCJ.

For Security and Higher Spectrum Efficiency: A Variable Packing Ratio Transmission System Based on Faster-Than-Nyquist and Deep Learning

With the rapid development of various services in wireless communications, spectrum resource has become increasingly valuable. Faster than Nyquist (FTN) signaling, proposed in the 1970s, is a promising paradigm for improving spectrum utilization. This paper proposes the variable-packing-ratio (VPR)-based transmissions for high spectrum efficiency (SE) and security, respectively. Aided by deep learning (DL)-based estimation, the proposed scheme for high SE can achieve a higher capacity than the conventional Nyquist-criterion transmission with negligible modification to existing communication paradigms (e.g., spectrum allocation or frame structure). More importantly, for VPR-based secure transmission, a dynamic generation scheme is proposed to produce randomly distributed positions to switch the packing ratio, which can effectively avoid detections and attacks. In addition, we propose a simplified DL-based packing ratio estimation for both of these two scenarios so that the receiver can estimate the packing ratio without any in-band or out-band control messages. Simulation results show that the proposed simplified estimation achieves nearly the same accuracy and convergence speed as the original multi-branch fully-connected structure with a complexity reduction of 20 folds. Finally, we derive the closed-form SE of the proposed VPR transmission under different channels. The numerical results validate the correctness of the derivation and demonstrate the SE gains of the VPR scheme beyond conventional Nyquist transmission.

THE STRATEGIC HGVS PLANNING PRACTICES FOR SUSTAINABLE GREEN LOGISTICS IMPLEMENTATION

The Malaysian government is introducing a number of initiatives to try and reduce the effects of global warming. One of these is the road haulage industry, which contributes significantly as one of Malaysia's largest industries to the nation's effort to reduce its transportation emissions to 45% by 2030. However, the empty movement of trucks and improper transport planning by the management caused some delivery trucks to come back to the headquarters empty and did not fully utilise the space of the vehicles. Therefore, the researchers aimed to propose heavy goods vehicle (HGV) planning practice to solve the problems. This is a mixed-mode research paper in which data was gathered through interviews and estimated calculations. The data has been analysed by comparing the result of the simple estimation calculation with the operational cost and carbon emission. Based on the results, most of them agreed that by using the right strategy, operational costs and carbon emissions can be reduced. The researchers had introduced a few recommendations to enhance the firm’s transport planning practices that could contribute to the field of green logistics as well as the road haulage industry in Malaysia.

Orbital Alignment of the Eccentric Warm Jupiter TOI-677 b

Warm Jupiters lay out an excellent laboratory for testing models of planet formation and migration. Their separation from the host star makes tidal reprocessing of their orbits ineffective, which preserves the orbital architectures that result from the planet-forming process. Among the measurable properties, the orbital inclination with respect to the stellar rotational axis, stands out as a crucial diagnostic for understanding the migration mechanisms behind the origin of close-in planets. Observational limitations have made the procurement of spin–orbit measurements heavily biased toward hot Jupiter systems. In recent years, however, high-precision spectroscopy has begun to provide obliquity measurements for planets well into the warm Jupiter regime. In this study, we present Rossiter–McLaughlin (RM) measurements of the projected obliquity angle for the warm Jupiter TOI-677 b using ESPRESSO at the VLT. TOI-677 b exhibits an extreme degree of alignment (λ = 0.3 ± 1.3 deg), which is particularly puzzling given its significant eccentricity (e ≈ 0.45). TOI-677 b thus joins a growing class of close-in giants that exhibit large eccentricities and low spin–orbit angles, which is a configuration not predicted by existing models. We also present the detection of a candidate outer brown dwarf companion on an eccentric, wide orbit (e ≈ 0.4 and P ≈ 13 yr). Using simple estimates, we show that this companion is unlikely to be the cause of the unusual orbit of TOI-677 b. Therefore, it is essential that future efforts prioritize the acquisition of RM measurements for warm Jupiters.

Assessing the duration of EDSS improvement after a therapy start: A novel approach applied to the long-term extension of the PRISMS study

In a chronic and progressive disease such as multiple sclerosis (MS), the improvement on Expanded Disability Status Scale (EDSS) can be a transient event. Therefore, estimating the prevalence of disability improvement over time, accounting both for improvement incidence and duration, is of interest. The aim of this study was to show the application of a simple estimator for the proportion of patients with sustained improvement over time using data from the long-term extension of the PRISMS trial. A total of 534 relapsing-remitting MS (RRMS) patients from the PRISMS trial were included. Patients with a baseline EDSS of 0 were excluded. Patients were randomized to placebo (n=178), subcutaneous interferon beta-1a (sc IFN β-1a) 22µg (n=181) or sc IFN β-1a 44µg (n=175). At Year 2, patients receiving placebo were re-randomized to sc IFN β-1a 22µg or 44µg (delayed sc IFN β-1a) while patients receiving sc IFN β-1a 22µg or 44µg continued their initial regimen. Patients were followed up for over 7 years post-randomization. Disability improvement was defined as a 1-point decrease in EDSS from baseline confirmed at 6 months. Prevalence of improvement was estimated as difference of Kaplan-Meier (KM) estimators while the cumulative incidence of improvement was calculated using the standard KM curves. No significant differences in cumulative incidence of EDSS improvement at 3 years between delayed sc IFN β-1a (20.3%) and sc IFN β-1a 22µg (20.8%; p=0.49) or 44µg (21.3%; p=0.33). When taking duration of improvement into account, the proportion of patients showing an improved condition after 3 years was 10.1% with delayed sc IFN β-1a, 11.3% with sc IFN β-1a 22µg (p=0.17) and 15.4% with sc IFN β-1a 44µg (p=0.037) that was substantially maintained over the long term. With the use of this new statistical methodology, it is possible to estimate the time to improvement as well as the duration of improvement, information that is better suited to describing a non-final outcome like disability improvement. In this case, early sc IFN β-1a 44µg initiation had a greater proportion of patients with a sustained disability improvement over a long period of follow-up as compared to patients who had initially been randomized to placebo. In contrast, no significant differences on the cumulative incidence of improvement were observed.