Variations In Dimensions Research Articles

Seakeeping analysis of dead ship condition in fishing ships based on Artificial Neural Networks

In the operation of ships, assessing seakeeping performance is crucial. Historically, this has been done through experimentation in towing tank basins or numerical computations. However, with the rise of Artificial Intelligence (AI) and increased computational resources, there are many opportunities to use AI in predicting seakeeping performance. This research will utilize a pre-trained Artificial Neural Network (ANN) to evaluate the behaviour of fishing vessels in various operational scenarios. One of the key advantages of using these algorithms is the ability to predict a large number of scenarios quickly, compared to traditional methods. By analysing millions of variations in the principal dimensions of a fishing ship and different sea states, the study aims to identify the optimal seakeeping performance in challenging conditions, ultimately improving ship safety by examining principal form coefficients and dimensions. The research will also determine significant conclusions.

Narcissism and the perception of failure - evidence from the error-related negativity and the error positivity.

The literature on narcissism suggests two contradictory ways how highly narcissistic individuals deal with their failures: They might avoid consciously recognising their failures to protect their ego or they might vigilantly turn towards their failures to process cues that are important for maintaining their grandiosity. We tried to dissolve these contradictory positions by studying event-related potential components of error processing and their variations with narcissism. With a speeded go/no-go task, we examined how the error-related negativity (Ne; reflecting an early, automatic processing stage) and the error positivity (Pe; associated with conscious error detection) vary with Admiration and Rivalry, two narcissism dimensions, under ego-threatening conditions. Using multilevel models, we showed that participants with high Rivalry displayed higher Ne amplitudes suggesting a heightened trait of defensive reactivity. We did not find variations of either narcissism dimension with the Pe, which would have pointed to weaker error awareness. Thus, our results only supported the second position: a heightened vigilance to errors in narcissism at early, rather automatic processing stages.

Impact of variation in size, shape and dimension of nanomaterial on Debye temperature and Raman frequency

A simple unified thermodynamic approach is developed to determine the effect of size on Raman frequency of nanomaterials. The model approach is based on the Bond energy model developed to determine cohesive energy of nanomaterials with respect to bulk material. The model formulation includes the size, dimension and shape of nanomaterial. The model approach is obtained extending the relation used to determine the effect of size and shape on Debye temperature of nanomaterials. Raman Frequency variation with size is studied for Si, CdSe, InP, CeO2, SnO2, ZnO nanocrystals. It is noted from the model calculations that Raman frequency of nanocrystals drop with decrease in the size at nano level resulting in Raman red shift. The experimental data of previous workers is found in good agreement with model results. The approach is further used to determine the Raman frequency variation with size and shape in nanoparticles and nanowires of varied shapes and nanofilms. Depending on the surface atoms to volume ratio in nanomaterials of varied shapes, variation in Raman frequency is studied and good consistency with the available data confirms the validity of the formulation.

Machine Learning-Assisted Device Modeling With Process Variations for Advanced Technology

Process variations (PV), including global variation (GV) and local variation (LV), have become one of the major issues in advanced technologies, which is crucial for circuit performance and yield. However, developing a mature and physics-based model is challenging and time-consuming. Thus, in this work, we propose a machine learning (ML) based method for device modeling with PV and implement the corresponding circuit simulation, which is demonstrated on advanced Nanosheet FETs (NSFET). Verified by TCAD simulations, the artificial neural network (ANN)-based ML algorithm enables to capture PV, e.g., dimension and work function variations (WFV), with high accuracy and improved efficiency. For GV, the ANN surrogated NSFET-based ring oscillator (RO) simulation results show that the larger width (Wsh) or height (Hsh) of the Nanosheet leads to the higher RO frequency and lower circuit delay. For LV, the respective impacts of grain size and WF on circuit performance can be distinguished. The proposed workflow, from ANN model training to circuit simulation based on the generated Verilog-A model, is fully automatic, promising to shorten the procedure of device modeling and accelerate the development of advanced technologies.

Sella can tell your age and gender: Determination of age and gender by evaluating the linear dimension of the sella turcica on lateral cephalogram - Retrospective study

ABSTRACT Background: In the lateral cephalogram, the sella turcica, a saddle-shaped concavity in the middle cranial fossa on the intracranial surface of the sphenoid bone, is clearly visible. Since it is utilized for forensic analysis, gender determination, and age determination, it is an excellent source of further diagnostic data regarding the estimation of the average sella turcica dimension and morphological variance in various age groups and genders. Aim: This study aims to determine the average dimension and morphological variations of the sella turcica in different age and gender groups on lateral cephalogram. Materials and Methods: The study sample consisted of 100 lateral cephalometric radiographs from patients 18 years or older. Linear Measurements: The length, depth, and anteroposterior diameter of the Sella Turcica were measured using the Silverman and Kisling methods. Statistical analysis was performed using the one-way ANOVA test and unpaired sample t-test. Results: In the present study, age-wise comparison of the linear measurement of sella turcica was not statistically significant in accordance with age with parameter P ≤ 0.05. Among the linear measurement, the parameter depth and diameter had statistically significant differences using parameter P ≤ 0.05 and unpaired t-test with gender. In gender-wise comparison, females tend to have higher sella turcica measurements than males. Conclusion: There was a statistically nonsignificant relation between age, and length, depth, and A-P diameter. There were statistically significant differences between sella turcica depth and diameter with genders.

FRACTAL DIMENSION VARIATION OF CONTINUOUS FUNCTIONS UNDER CERTAIN OPERATIONS

In this paper, we make research on the fractal structure of the space of continuous functions and explore how the fractal dimension of continuous functions under certain operations changes. We prove that any nonzero real power and the logarithm of a positive continuous function can keep the fractal dimensions of bi-Lipschitz invariance closed. For continuous functions having finite zero points, the relationship between its global behavior and the local behavior of its square on zero points has been given. Further, we discuss the fractal dimension of the product of continuous functions and provide the product decomposition of a continuous function in terms of the lower and upper box dimensions. Some special properties of the space of one-dimensional continuous functions have also been shown.

Static analysis of multi-support stepped spindle shafts with nonlinear elastic bearings

In this paper a mathematical model and a computational technique for the static analysis of multi-support stepped spindle shafts on nonlinear elastic supports are presented. On the basis of the Timoshenko differential equation of the beam's bent axis and the method of initial parameters, a resolving system of equations is obtained that takes into account the nonlinear dependency of the stiffness of the bearings on the forces acting on them along with the stepwise variation of the cross-sectional dimensions of the shaft. A numerical method for solving the problem has been proposed and a software tool has been developed, which performs the static analysis of multi-support stepped spindle shafts on nonlinear elastic supports in MATLAB environment.

Determination of Nominal Dimensions and Permissible Variations in Dimensions of Critical Parts of Foreign Machinery Units

Introduction. Developing and adapting domestic technologies aimed at the maintenance and repair of foreign equipment is impossible without design documentation. The object of the study was the volumetric hydraulic drive Sauer-Danfoss of 90 series consisting of a hydraulic pump 90R100 and a hydraulic motor 90M100. The purpose of the study is to determine the nominal dimensions and permissible variations in dimensions of critical parts that affect efficiency of the foreign hydraulic drive. Materials and Methods. The first series of bench tests was devoted to finding the ranges of variation of significant factors influencing the volumetric efficiency. In the second series, there were constructed regression models and by using the steepest ascend method, there were determined the values of critical parts wear and clearances in the critical parts connections affecting efficiency of the hydraulic drive Sauer-Danfoss. The nominal values of dimensions and permissible variations in dimensions of the hydraulic drive critical parts were determined by the dimensional analysis method. Results. The bench tests made it possible to determine the ranges of changes in critical parts wear and clearances in the critical parts connections of volumetric hydraulic drives that affect the volumetric efficiency. There has been proposed and implemented a comprehensive approach to determining the nominal dimensions and permissible variations in dimensions of critical parts of foreign equipment units. This approach suggests a combination of experimental studies (bench tests) and the method of dimensional analysis. For the new volumetric hydraulic drive Sauer-Danfoss series 90 the following values are received: diameter of a hole in the cylinder block under the piston 22,7+0,006 mm, piston diameter 22,7–0,004 mm, diameter of a hole in the rear cover under the spool 9,5+0,004 mm, spool diameter 9,5–0,0025 mm. Discussion and Conclusion. There have been determined the nominal values of dimensions, permissible variations in dimensions of critical parts, and the values of technological clearances in the critical parts connections of the new volumetric hydraulic drive Sauer-Danfoss series 90 that affect its efficiency. The results obtained are the basis for the development of technology to restore the efficiency and increase the durability of the volumetric hydraulic drive units of foreign origin.

Mean Differences in Student Dimension, Technology Characteristic, Instructor Characteristic Based on Demography Factors

The worldwide COVID 19 epidemic that occurred in 2019 had a huge impact on everyone's lives. Nearly all sectors and industries have experienced a substantial impact as a result of the pandemic. The Movement Control Order was put into effect by the government in March 2020, which caused a disruption in people's routines. Higher education is one of the industries that have undergone significant overall change. The teaching and learning process continues throughout MCO, shifting from in-person instruction to online distant learning (ODL). Regardless of demographic differences, family economic circumstances, or unsuitable and uncomfortable learning conditions at home, all students are compelled to participate in ODL learning sessions. Examining the variations in student dimensions, technology characteristics, and instructor characteristics based on demographic factors is the main objective of this work. Gender, the student's current location (campus or hometown), the area (urban or rural), and the student's response to the question "Do you have a proper study area?" are all examples of demographic factors. The study's findings show that the area for instructor characteristic satisfaction score and respondents' gender only differ by a statistically significant result. Gender, respondent area, and study area conditions all varied significantly in terms of the student dimension satisfaction score. The technology characteristic satisfaction score did not show any notable variations for any of the categories.

Research on macroscopic mechanical properties and microscopic evolution characteristic of sandstone in thermal environment

To study macro and micro characteristics of rock and their correlation in high temperature environment, uniaxial compression experiment is conducted to analyze macroscopic mechanical properties of sandstone samples after different temperature treatment, and AE source location technology is used to study corresponding microscopic evolution characteristics. Then, the correlation between macroscopic mechanical properties and microscopic evolution characteristics is discussed qualitatively, and their quantitative relationship is revealed further. The research results show that the brittleness of the sandstone sample experiences transform process of “first increasing and then decreasing” as treatment temperature increases from room temperature to 1000 °C and turning point is 400 °C, according to the change trend in peak stress, peak strain and fracture characteristics. Based on the variations of fractal dimension and microfracture type of AE events, it is evident that the microcrack system of the sandstone sample experiences the change process of “first simple and then complex” with an increase of treatment temperature. The reason for these variations is that treatment temperature can change microcrack system through the game process of thermal healing effect and thermal fracture effect, resulting in the difference of macroscopic mechanical properties. As treatment temperature increases from room temperature to 400 °C, thermal healing effect is always stronger than thermal fracture effect and the difference enlarges continuously. The microcrack system shrinks gradually, and the sandstone sample presents less properties of the microcrack system and its brittleness increase. As treatment temperature is above 400 °C, a continued increase in treatment temperature makes the difference between the two effects start to decreases until thermal fracture effect exceeds thermal healing effect, then their difference enlarges again. The microcrack system develops gradually, and the sandstone sample presents more properties of the microcrack system and its brittleness decrease. Further, according to data fitting analysis, it can be considered that thermal healing effect presents a linear correlation with treatment temperature during the game process and thermal fracture effect shows an nonlinear correlation with treatment temperature. The difference in the increase rate of these two effects results in nonlinear relationship between the microcrack system and treatment temperature. Then, the linear relationship between the microcrack system and macroscopic mechanical properties is reveal and quantitative relationship model between macroscopic mechanical properties and treatment temperature is established, which has good agreement with the experimental data. This research is helpful to know the correlation of macro and micro variations of the sandstone sample in high temperature environment. It possesses important guiding significance and reference value for ensuring stability of the surrounding rock in deep underground engineering.

Numerical Study of GaP Nanowires: Individual and Coupled Optical Waveguides and Resonant Phenomena.

The development of novel nanophotonic devices and circuits necessitates studies of optical phenomena in nanoscale structures. Catalyzed semiconductor nanowires are known for their unique properties including high crystallinity and silicon compatibility making them the perfect platform for optoelectronics and nanophotonics. In this work, we explore numerically optical properties of gallium phosphide nanowires governed by their dimensions and study waveguiding, coupling between the two wires and resonant field confinement to unveil nanoscale phenomena paving the way for the fabrication of the integrated optical circuits. Photonic coupling between the two adjacent nanowires is studied in detail to demonstrate good tolerance of the coupling to the distance between the two aligned wires providing losses not exceeding 30% for the gap of 100 nm. The dependence of this coupling is investigated with the wires placed nearby varying their relative position. It is found that due to the resonant properties of a nanowire acting as a Fabry-Perot cavity, two coupled wires represent an attractive system for control over the optical signal processing governed by the signal interference. We explore size-dependent plasmonic behaviors of the metallic Ga nanoparticle enabling GaP nanowire as an antenna-waveguide hybrid system. We demonstrate numerically that variation of the structure dimensions allows the nearfield tailoring. As such, we explore GaP NWs as a versatile platform for integrated photonic circuits.

Dynamic Anti-Counterfeiting Labels with Enhanced Multi-Level Information Encryption

Information encryption is an important means to improve the security of anti-counterfeiting labels. At present, it is still challenging to realize an anti-counterfeiting label with multi-function, high security factor, low production cost, and easy detection and identification. Herein, using inkjet and screen printing technology, we construct a multi-dimensional and multi-level dynamic optical anti-counterfeiting label based on instantaneously luminescent quantum dots and long afterglow phosphor, whose color and luminous intensity varied in response to time. Self-assembled quantum dot patterns with intrinsic fingerprint information endow the label with physical unclonable functions (PUFs), and the information encryption level of the label is significantly improved in view of the information variation in the temporal dimension. Furthermore, the convolutional residual neural networks are used to decode the massive information of PUFs, enabling fast and accurate identification of the anti-counterfeit labels.

Solution of the plane problem of the theory of elasticity on bending of an articulated fixed multilayer panel with a circular axis

This article suggests a method for the solution of the plane problem of the theory of elasticity on the bending of an articulated fixed multilayered panel with a circular axis based on the polynomial approximation of displacements through the thickness of the panel. In contrast to the known solutions of this problem, in this case the coefficients of the approximating polynomials are calculated from the equilibrium conditions and equality of displacements and transverse stresses at the transition across the layer interface and solution of differential equations of equilibrium at several points through the thickness of the layers. Finally, the problem is reduced to the solution of a system of linear equations with respect to the coefficients of approximating polynomials. The validity of the method is confirmed by comparing the results of calculations obtained on its basis and the results obtained with the help of the reference finite element model. The problem is solved in two stages. At the first stage, for a single-layer panel, we investigate the dependence of the polynomial degree on the ratio of the average panel radius to its thickness and the ratio of the transverse shear modulus to the modulus of longitudinal elasticity, which characterize the nonlinearity of displacements. At the second stage, on the example of a three-layered panel, we consider the application of the proposed method for the calculation of multilayered panels. In such case, the results obtained at the first stage are used in selecting the initial degree of polynomials approximating displacements through the thickness of layers. The method proposed in this article makes it possible to obtain an analytical solution without introducing simplifying hypotheses about the nature of displacement of layers and their elastic characteristics in a wide range of variation in geometric dimensions and elastic characteristics of panel layers. This method can be used both for verification of numerical models and for carrying out strength calculations of multilayer panels.

Three-Dimensional Thermo-Mechanical Elastic Analysis of Functionally Graded Five Layers Composite Sandwich Plate on Winkler Foundations

In this work, the first shear deformation theory (FSDT) is used for the thermo-mechanical analysis of a simply supported five-layer functionally Graded (FG) sandwich plate resting on a Winkler elastic foundation. The sandwich plate consists of five layers (two functionally graded face sheets (AL−AL2O3), with aluminum (Al) as the metal and Alumina (AL2O3) as ceramic phases. Two vinyl ester adhesive layers bond the face sheets to an Elastollan core. The governing equations are obtained using the principle of virtual displacements. A uniform distributed load q with constant magnitude is applied on the top face sheet while all layers experience a steady temperature equal to T. We adapted layerwise theory (LT) to solve each layer’s stress distribution. Navier solution is employed to produce the semi-analytical solution results, which are compared with those of three-dimensional finite element analysis obtained by ABAQUS software. A parametric study is presented to observe the effect of the material gradation, variation in plate dimensions, variation in the thermo-mechanical load, and elastic foundation on the deflections and stresses in the functionally graded sandwich plate. For a composite sandwich plate with mechanical load, in the absence of thermal load, results of the first-order shear layer theory obtained by using the Navire method are relatively good in comparison to the normal stresses obtained for investigated points, which are obtained by finite element.

Quality appraisal for systematic literature reviews of health state utility values: a descriptive analysis

BackgroundHealth state utility values (HSUVs) are an essential input parameter to cost-utility analysis (CUA). Systematic literature reviews (SLRs) provide summarized information for selecting utility values from an increasing number of primary studies eliciting HSUVs. Quality appraisal (QA) of such SLRs is an important process towards the credibility of HSUVs estimates; yet, authors often overlook this crucial process. A scientifically developed and widely accepted QA tool for this purpose is lacking and warranted.ObjectivesTo comprehensively describe the nature of QA in published SRLs of studies eliciting HSUVs and generate a list of commonly used items.MethodsA comprehensive literature search was conducted in PubMed and Embase from 01.01.2015 to 15.05.2021. SLRs of empirical studies eliciting HSUVs that were published in English were included. We extracted descriptive data, which included QA tools checklists or good practice recommendations used or cited, items used, and the methods of incorporating QA results into study findings. Descriptive statistics (frequencies of use and occurrences of items, acceptance and counterfactual acceptance rates) were computed and a comprehensive list of QA items was generated.ResultsA total of 73 SLRs were included, comprising 93 items and 35 QA tools and good recommendation practices. The prevalence of QA was 55% (40/73). Recommendations by NICE and ISPOR guidelines appeared in 42% (16/40) of the SLRs that appraised quality. The most commonly used QA items in SLRs were response rates (27/40), statistical analysis (22/40), sample size (21/40) and loss of follow up (21/40). Yet, the most commonly featured items in QA tools and GPRs were statistical analysis (23/35), confounding or baseline equivalency (20/35), and blinding (14/35). Only 5% of the SLRS used QA to inform the data analysis, with acceptance rates of 100% (in two studies) 67%, 53% and 33%. The mean counterfactual acceptance rate was 55% (median 53% and IQR 56%).ConclusionsThere is a considerably low prevalence of QA in the SLRs of HSUVs. Also, there is a wide variation in the QA dimensions and items included in both SLRs and extracted tools. This underscores the need for a scientifically developed QA tool for multi-variable primary studies of HSUVs.

VTDCE-Net: A time invariant deep neural network for direct estimation of pharmacokinetic parameters from undersampled DCE MRI data.

To propose a robust time and space invariant deep learning (DL) method to directly estimate the pharmacokinetic/tracer kinetic (PK/TK) parameters from undersampled dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI)data. DCE-MRI consists of 4D (3D-spatial + temporal) data and has been utilized to estimate 3D (spatial) tracer kinetic maps. Existing DL architecture for this task needs retraining for variation in temporal and/or spatial dimensions. This work proposes a DL algorithm that is invariant to training and testing in both temporal and spatial dimensions. The proposed network was based on a 2.5-dimensional Unet architecture, where the encoder consists of a 3D convolutional layer and the decoder consists of a 2D convolutional layer. The proposed VTDCE-Net was evaluated for solving the ill-posed inverse problem of directly estimating TK parameters from undersampled space data of breast cancer patients, and the results were systematically compared with a total variation (TV) regularization based direct parameter estimation scheme. In the breast dataset, the training was performed on patients with 32 time samples, and testing was carried out on patients with 26 and 32 time samples. Translation of the proposed VTDCE-Net for brain dataset to show the generalizability was also carried out. Undersampling rates (R) of 8× , 12× , and 20× were utilized with PSNR and SSIM as the figuresof merit in this evaluation. TK parameter maps estimated from fully sampled data were utilized as groundtruth. Experiments carried out in this work demonstrate that the proposed VTDCE-Net outperforms the TV scheme on both breast and brain datasets across all undersampling rates. For and maps, the improvement over TV is as high as 2 and 5 dB, respectively, using the proposedVTDCE-Net. Temporal points invariant DL network that was proposed in this work to estimate the TK-parameters using DCE-MRI data has provided state-of-the-art performance compared to standard image reconstruction methods and is shown to work across all undersamplingrates.

Acoustic radiation through a flexible shell in a bifurcated circular waveguide

The current study models and explains the fluid–structure coupled response of a flexible shell connected with two rigid coaxial shells via circular step discontinuities. Radiations from annular and inner regions of inlet rigid shells scatter on interfaces after interaction with the geometric variations and change of material properties. The flexible shell that supports vibrations along the shell is expressed though the Donnell–Mushtari formulation in the differential system. The mode‐matching technique is applied to solve the governing boundary value problem. The solution is projected on the orthogonal characteristics which in flexible casing is generalized as compared with the properties of acoustically rigid setting. The implication of generalized orthogonality relations governs additional constants that are found by defining the physical connection of shell with rigid disc. The clamped and pin‐jointed conditions are considered in this article. The scattering powers and transmission loss are analyzed against frequency, chamber length, and radii of shells for clamped and pin‐jointed edge conditions. It is found that the power propagation in annular shell and inner shell behave conversely. Moreover, configuration can be attenuated through the variation of dimensions of chamber and edge conditions.

Progressive failure analysis of U-notched thin composite plates repaired with a double-sided composite patch

In this study, carbon fiber-reinforced U-notched composite plates were repaired with composite patches made of the same material using adhesive bonding and their mechanical performance was investigated experimentally and numerically. Repairs were made by applying a double-sided composite patch to the notched thin composite plates. The repaired composite plates were tested under tensile load. The effect of the variation in notch width and depth on the repaired plate failure load and type was investigated. At the end of the experiments, load–displacement graphs of each specimen were obtained. The effect of variation in notch depth and width in the repaired specimens was not as dominant as in the non-repaired specimens. While the variation in notch dimensions changed the failure load between 34% and 37% in the non-repaired specimens, this rate was between 18% and 21% in the repaired specimens. In the numerical analysis, progressive failure analysis was performed using the Hashin Failure Criteria. Subroutine codes were written in the program Ansys, which uses the finite element method for numerical analysis. In the results, numerical and experimental load–displacement graphs and failure types of the specimens are presented comparatively. The convergence rate of the experimental and numerical data was between 92% and 99.8%.

Equivalent circuit approach for the design of hole and slot bare anode block of magnetron

Magnetron is a high-power microwave source with high demand among vacuum devices. Before the design, validating it with other methods gives confidence to the designer. An equivalent circuit analysis is developed for a 16 vanes hole and slot structure yielding the design parameters, hole radius, slot length, slot width, and anode height. This method is adopted to calculate the cavity resonant frequencies preferable over the field equations, simulation, and fabrication. From inductance and capacitance definition, dispersion equation of the anode block is derived for each mode. The equivalent circuit approach is validated with the simulation to verify consistency. The resonant frequency relative difference of these two methods is 1.46%. The inductance and capacitance changes are observed by parametric variation of these structure dimensions. Strapping causes the frequency shift from 3.1685 to 2.217 GHz, and change in the cavity resonant frequency with the strap depth and strap height are plotted.

A Study on the Resolution and Depth of Focus of ArF Immersion Photolithography.

In this study, the resolution and depth of focus (DOF) of the ArF immersion scanner are measured experimentally according to numerical aperture (NA). Based on the experiment, the theoretical trade-off relationship between the resolution and depth of focus can be confirmed and k1 and k2 are extracted to be about 0.288 and 0.745, respectively. Another observation for a problem in small critical dimension realization is the increase in line width roughness (LWR) according to mask open area ratio. To mitigate the trade-off problem and critical dimension variation, the photoresist thickness effect on depth of focus is analyzed. Generally, the photoresist thickness is chosen considering depth of focus, which is decided by NA. In practice, the depth of focus is found to be influenced by the photoresist thickness, which can be caused by the intensity change of the reflected ArF light. This means that photoresist thickness can be optimized under a fixed NA in ArF immersion photolithography technology according to the critical dimension and pattern density of the target layer.