Classical Correlations Research Articles

Entropy-based geometric measures of correlations for bell diagonal states via measurement

Abstract The classification and quantification of quantum correlations are the important issues in quantum information theory. Quantum relative entropy and Rényi relative entropy are both non-negative, and can therefore be regarded as generalized distances between quantum states. We first introduced the method proposed by Brodutch and Modi for constructing measurements of classical and quantum correlations. Subsequently, we use this method to construct measurement-induced geometric classical and quantum correlations based on quantum relative entropy and Rényi− 1 2 relative entropy. For two-qubit Bell diagonal states, the analytic expressions for these geometric classical correlations and quantum correlations are obtained.

Experimental investigation on transitional flow of supercritical hydrocarbon fuel within straight channels of Printed Circuit Heat Exchangers for hypersonic thermal management systems

The onboard supercritical CO2 closed Brayton cycle (SCBC) has established an effective thermal management pathway for hypersonic vehicles operating at high Mach numbers. A Printed Circuit Heat Exchanger (PCHE) is employed within the cycle system to facilitate heat transfer between fuel and carbon dioxide, with its thermo-hydraulic characteristics significantly impacting both power generation and propulsion performance. Given the insufficient research on the flow and heat transfer of hydrocarbon fuels in PCHEs, this study aims to experimentally address the gaps in understanding transition flow for supercritical hydrocarbon fuels, particularly within semi-circular microchannels. We conducted experiments on the flow transitions using a specially designed test piece with a diameter of 1 mm, replicating the PCHE channel characteristics. The experimental Reynolds number range from 300 to 8300 spans laminar, transition, and turbulent flow regimes. Friction factors for n-decane are obtained under adiabatic and heated conditions. The results validate the nomenclature of the quasi-turbulent region and reveal that the critical Reynolds numbers for the transitional, quasi-turbulent and hydraulic smooth turbulent regions under adiabatic conditions are 2200, 2440 and 2980, respectively. A reduction in friction drag attributed to boundary layer viscosity is observed to alter the friction factor under heating conditions, while heating influences both the onset and termination of the transition region, but does not affect its width. Classical correlations are compared with the experimental results, and new empirical correlations for both adiabatic and non-adiabatic conditions are developed, showing superior predictive accuracy compared to existing models. This provides a reliable tool for the engineering design of heat exchangers in the onboard thermal manage systems.

Spatiotemporal pattern of ENSO-induced modulation on landscape fires over Pacific Rim from 2001‒2020

While El Niño-Southern Oscillation (ENSO) modulates landscape fire activities across the Pacific Rim, the detailed patterns and mode-specific variations of these effects remain poorly understood. This study aims to address that gap by systematically assessing the spatiotemporal variations in burned areas from 2001‒2020 during different modes of ENSO, namely, Eastern Pacific (EP) El Niño, EP La Niña, Central Pacific (CP) El Niño and CP La Niña. We evaluate the modulation patterns using classical correlation and cross-spectrum analyses, focusing on five hotspot regions: Temperate North America (TENA), Southern Hemisphere South America (SHSA), Northern Hemisphere South America (NHSA), Equatorial Asia (EQAS) and Australia and New Zealand (AUST). El Niño and La Niña exhibit asymmetrical opposite effects on burned areas, as expected. The findings reveal spatial non-uniformity in the impact of ENSO on landscape fires, with La Niña enhancing burned areas in TENA and SHSA, whereas El Niño predominantly affects AUST, EQAS and NHSA. CP and EP ENSO events differ in intensity and their large-scale circulation patterns. These differences cause notable variations in the regional burned area. Water vapour redistribution emerges as the key driver. The study emphasises the heterogeneity in ENSO modes in regulating landscape fires, providing insights for future landscape fire risk assessment and prevention efforts under climate change.

Some Characterizations for Partial Classical Correlation States in Multipartite Quantum Systems

Some Characterizations for Partial Classical Correlation States in Multipartite Quantum Systems

Drivers of summer Arctic sea-ice extent at interannual time scale in CMIP6 large ensembles revealed by information flow

Arctic sea-ice extent has strongly decreased since the beginning of satellite observations in the late 1970s. While several drivers are known to be implicated, their respective contribution is not fully understood. Here, we apply the Liang-Kleeman information flow method to five different large ensembles from the Coupled Model Intercomparison Project Phase 6 (CMIP6) over the 1970-2060 period to investigate the extent to which fluctuations in winter sea-ice volume, air temperature and ocean heat transport drive changes in subsequent summer Arctic sea-ice extent. This allows us to go beyond classical correlation analyses. Results show that air temperature is the most important controlling factor of summer sea-ice extent at interannual time scale, and that winter sea-ice volume and Atlantic Ocean heat transport play a secondary role. If we replace air temperature by net shortwave and downward longwave radiations, we find that the sum of influences from both radiations is almost similar to the air temperature influence, with the longwave radiation being dominant in driving changes in summer sea-ice extent. Finally, we find that the influence of air temperature is more prominent during periods of large sea-ice reduction and that this temperature influence has overall increased since 1970.

Adaptation of digital gamification in professional education amid martial law challenges

Introduction: The growing interest within the scientific community in the potential of gamification in professional education during wartime drives the relevance of this research. Objective: The main aim of this article is to identify the significance of positive and negative factors in gamification in professional education and analyse their impact on the educational environment. Methods: The research used scientific literature analysis, statistical data analysis, and generalisation and systematisation to substantiate the main features and positive and negative aspects of gamification in professional education. To justify the feasibility of applying gamification elements in the Ukrainian context, an expert survey of lecturers was conducted, which allowed for the formation of weighted average indicators by criteria using Excel tools and the performance of a correlation SWOT analysis in the JASP program (Classical Correlation tool). Results: The analysis revealed that lecturers rate the advantages and opportunities of gamification higher than the challenges and threats. Positive effect include of gamification on the development of students' collaborative skills, engagement, and motivation, however, negative consequences the creation of unhealthy competition, reduced learning effectiveness, and the need for enhanced control over game elements. Conclusions: The research identified that the main aspects that will contribute to the effective integration of game elements into the learning process are an integrated approach, infrastructure reliability, flexibility, and adaptability of educational programmes, which will ensure the further development of approaches to student engagement and the enhancement of their motivation in the process of acquiring professional skills.

THE INFLUENCE OF TRAINING AND WORK ENVIRONMENT ON EMPLOYEE PERFORMANCE AT PT SAMWON COPPER TUBE INDONESIA

The objective of this study is to determine the influence of training and work environment on employee performance at PT Samwon Copper Tube Indonesia in Tangerang Regency, Banten. The method used is quantitative. The sampling technique used is saturated sampling, meaning all members of the population are used as the sample, resulting in a sample of respondents in this study. Data analysis was conducted using validity tests, reliability tests, classical assumption tests, regression analysis, correlation coefficients, determination coefficients, and hypothesis testing. The study results indicate that training has a positive and significant effect on employee performance, with a regression equation showing a direct relationship. The coefficient of determination shows that part of the variation in employee performance can be explained by the training variable, and hypothesis testing results indicate a positive and significant influence of training on employee performance at PT Samwon Copper Tube Indonesia in Tangerang Regency, Banten. The work environment also has a positive and significant effect on employee performance, with a regression equation showing a direct relationship. The coefficient of determination shows that part of the variation in employee performance can be explained by the work environment variable, and hypothesis testing results indicate a positive and significant influence of the work environment on employee performance at PT Samwon Copper Tube Indonesia in Tangerang Regency, Banten. Training and work environment simultaneously have a positive and significant effect on employee performance, with a regression equation indicating the contribution of these two variables together. The coefficient of determination shows that a large portion of the variation in employee performance can be explained by training and work environment, while the remainder is influenced by other factors. Hypothesis testing results indicate a positive and significant influence of training and work environment simultaneously on employee performance at PT Samwon Copper Tube Indonesia in Tangerang Regency, Banten.

THE INFLUENCE OF SERVICE QUALITY AND PRICE ON PURCHASE DECISIONS IN CLOTHING STORES AT PARUNG MARKET

This study aims to identify the influence of service quality and price on the purchase decisions of clothing at stores in Parung Market, both partially and simultaneously. The research is associative and quantitative, with consumers of Parung Market stores as the subjects. The sample consists of 90 individuals selected using Slovin’s formula. Data collection was done through questionnaires, and the data were analyzed using various tests, such as validity and reliability tests, classical assumption tests, linear regression, correlation coefficient, determination coefficient, and partial and simultaneous hypothesis testing. All analyses were performed using SPSS version 25. The results show that service quality affects purchase decisions, with a positive relationship demonstrated by the regression equation. The correlation coefficient indicates a fairly strong relationship between service quality and purchase decisions. In addition, price has a significant influence on purchase decisions, with a higher correlation coefficient compared to service quality. Simultaneously, both service quality and price together influence purchase decisions. This relationship is strengthened by the high and significant correlation coefficient. The conclusion of this study is that both service quality and price, individually or together, play an important role in influencing consumer purchase decisions at Parung Market.

Sexual somatic dimorphism in connection with ecological factors

Introduction. Analysis of correlations of sexual somatic dimorphism (SD) with the degree of urbanization (quantity of population) and geographic latitude of the residence place is carried out using the material of monitoring of Russian children and adolescents. Material and methods. The study embraces the wide specter of ethno-territorial samples of children and adolescents from Russia and neighboring countries (literary data), examined through the historic interval 1930-2010 years. To estimate the direction and degree of associations of anthropometric traits (height, weight, chest girth) and ecological factors the classic correlation analysis for pairwise combinations of variables was implemented for age groups of 9-year-old children and 13-year-old adolescents. The quantitative estimation of SD was carried out using Kullback divergence, the analogue of Makhalanobis distance. Results. Significant correlations of SD of height with both ecological factors for 13-year-old adolescents and SD of weight for 9-year-old children with the quantity of population were fixed on base of the whole data massive. The more homogeneous data base (only Slavonic groups examined in 1960s-1970s) shows significant correlations of latitude with SD of height for 13-year-old adolescents only in combination with the quantity of population of the residence place up to 500 thousands of people; and latitude with SD of weight for 9-year-old children only for million-plus cities. Significant correlations of quantity of population were fixed for SD of height of 13-year-old adolescents in more southern ranges of latitude (37-50degrees), for SD of weight for 9-year-old children in more northern ranges of latitude (50 degrees and more). Conclusion. The study shows complex superposition of ecological factors, which influence somatic variability of children through growth process. High degree of urbanization conceal anthropoecological correlations SD-latitude for ecosensitive age 13 years, but reveal them for “neutral” age, 9 years, with the opposite vector. The most southern range of latitudes (about 40 degrees) reveal positive associations of SD with the degree of urbanization for 13-year-olds, which are not fixed in more northern latitudes. More frequent anthropoecological correlations of SD of height, as genetic marker, of 13-year-olds, and SD of weight as the marker of nutrition status and life style of 9-year-olds reflect the physiological essence of age periods - increase of intersex differences for adolescents and decrease of intersex differences for second childhood children

Deriving Three-Outcome Permutationally Invariant Bell Inequalities.

We present strategies to derive Bell inequalities valid for systems composed of many three-level parties. This scenario is formalized by a Bell experiment with N observers, each of which performs one out of two possible three-outcome measurements on their share of the system. As the complexity of the set of classical correlations prohibits its full characterization in this multipartite scenario, we consider its projection to a lower-dimensional subspace spanned by permutationally invariant one- and two-body observables. This simplification allows us to formulate two complementary methods for detecting nonlocality in multipartite three-level systems, both having a complexity independent of N. Our work can have interesting applications in the detection of Bell correlations in paradigmatic spin-1 models, as well as in experiments with solid-state systems or atomic ensembles.

Measuring, processing, and generating partially coherent light with self-configuring optics

Optical phenomena always display some degree of partial coherence between their respective degrees of freedom. Partial coherence is of particular interest in multimodal systems, where classical and quantum correlations between spatial, polarization, and spectral degrees of freedom can lead to fascinating phenomena (e.g., entanglement) and be leveraged for advanced imaging and sensing modalities (e.g., in hyperspectral, polarization, and ghost imaging). Here, we present a universal method to analyze, process, and generate spatially partially coherent light in multimode systems by using self-configuring optical networks. Our method relies on cascaded self-configuring layers whose average power outputs are sequentially optimized. Once optimized, the network separates the input light into its mutually incoherent components, which is formally equivalent to a diagonalization of the input density matrix. We illustrate our method with numerical simulations of Mach-Zehnder interferometer arrays and show how this method can be used to perform partially coherent environmental light sensing, generation of multimode partially coherent light with arbitrary coherency matrices, and unscrambling of quantum optical mixtures. We provide guidelines for the experimental realization of this method, including the influence of losses, paving the way for self-configuring photonic devices that can automatically learn optimal modal representations of partially coherent light fields.

Finite-temperature Rydberg arrays: Quantum phases and entanglement characterization

As one of the most prominent platforms for analog quantum simulators, Rydberg atom arrays are a promising tool for exploring quantum phases and transitions. While the ground-state properties of one-dimensional Rydberg systems are already thoroughly examined, we extend the analysis towards the finite-temperature scenario. For this purpose, we develop a tensor network-based numerical toolbox for constructing the quantum many-body states at thermal equilibrium, which we exploit to probe classical correlations as well as entanglement monotones. We clearly observe ordered phases continuously shrinking because of thermal fluctuations at finite system sizes. Moreover, by examining the entanglement of formation and entanglement negativity of a half-system bipartition, we numerically confirm that a conformal scaling law of entanglement extends from the zero-temperature critical points into the low-temperature regime. Published by the American Physical Society 2024

The Effect of Service Prices and Service Quality on Consumer Satisfaction at PT. Paramita Ban Workshop Cipete, South Jakarta Period 2023

The purpose of this study is to determine the influence of service price and service quality on consumer satisfaction at the PT Paramita Ban Cipete Workshop in South Jakarta. The method used is quantitative. The sampling technique used saturated sampling and a sample of 98 respondents was obtained. Data analysis uses validity tests, reliability tests, classical assumption tests, regression analysis, correlation coefficients, determination coefficients and hypothesis tests. The results of this study are that the price of services has a significant effect on consumer satisfaction with a determination coefficient value of 25.2% and the hypothesis test is obtained t calculation > t table or (4.788 > 1.988). The quality of service did not have a significant effect on consumer satisfaction with a determination coefficient value of 74.8% and the hypothesis test was obtained by calculating t < t table or (1,616 < 1,988). Service price and service quality simultaneously have a significant effect on consumer satisfaction with the regression equation Y = 19,999 + 0.414 (X1) Y = 19,999 + 0.134 (X2). The value of the determination coefficient was 25.2% while the remaining 74.8% was influenced by other factors. The hypothesis test obtained the F value calculated > F table or (17.764 > 3.094).

Scalable determination of multipartite entanglement in quantum networks

Quantum networks comprised of entangled end nodes serve stronger than the classical correlation for unparalleled quantum internet applications. However, practical quantum networking is affected by noise, which at its worst, causes end nodes to be described by pre-existing classical data. In such untrusted networks, determining quantum network fidelity and genuine multi-node entanglement becomes crucial. Here, we show that determining quantum network fidelity and genuine N-node entanglement in an untrusted star network requires only N + 1 measurement settings. This method establishes a semi-trusted framework, allowing some nodes to relax their assumptions. Our network determination method is enabled by detecting genuine N-node Einstein-Podolsky-Rosen steerability. Experimentally, using spontaneous parametric down-conversion entanglement sources, we demonstrate the determinations of genuine 3-photon and 4-photon quantum networks and the false positives of the widely used entanglement witness, the fidelity criterion of 1/2. Our results provide a scalable method for the determination of multipartite entanglement in realistic quantum networks.

Pengaruh Kepemimpinan dan Disiplin Kerja Terhadap Kinerja Karyawan Pada CV Bintang Makmur Bekasi

Influence of Leadership and Work Discipline on Employee Performance at CV. Bintang Makmur Bekasi.This research aims to find out how the relationship between the variables Leadership (X1) and Work Discipline (X2) influences the Employee Performance variable (Y) at CV Bintang Makmur Bekasi. Research data is data taken using a questionnaire distributed to CV Bintang Makmur Bekasi employees. The population in this study were 44 employees of CV Bintang Makmur Bekasi. Data analysis techniques Data using Descriptive Analysis, Validity Test, Reliability, Simple, Multiple Regression Analysis, Classical Assumption Test, t Test (Partial), F Test (Simultaneous), Correlation Coefficient and Determination. Data processing in research uses SPSS 29. Based on the results, simultaneous tests produce a significance value of 0.001 < 0.05, which means that leadership and work discipline influence employee performance. Furthermore, the results of the coefficient of determination show a figure of 0.885, so 88.5% of Leadership (X1) and Work Discipline (X2) influence Employee Performance (Y) at CV Bintang Makmur Bekasi, while the remaining 21.5% is influenced by intervening variables which Thus, it can be concluded that the first hypothesis (Ha1), second hypothesis (Ha2), and third hypothesis (Ha3) can be accepted.

Quantum fluctuation dynamics of open quantum systems with collective operator-valued rates, and applications to Hopfield-like networks

We consider a class of open quantum many-body systems that evolves in a Markovian fashion, the dynamical generator being in GKS-Lindblad form. Here, the Hamiltonian contribution is characterized by an all-to-all coupling, and the dissipation features local transitions that depend on collective, operator-valued rates, encoding average properties of the system. These types of generators can be formally obtained by generalizing, to the quantum realm, classical (mean-field) stochastic Markov dynamics, with state-dependent transitions. Focusing on the dynamics emerging in the limit of infinitely large systems, we build on the exactness of the mean-field equations for the dynamics of average operators. In this framework, we derive the dynamics of quantum fluctuation operators, that can be used in turn to understand the fate of quantum correlations in the system. We then apply our results to quantum generalized Hopfield associative memories. Here we show that, asymptotically and at the description level of quantum fluctuations, only a very weak amount of quantum correlations, in the form of quantum discord, emerges beyond classical correlations.

Numerical investigation on dynamic flow characteristics of methane condensation in microchannels

Microchannel condensers play an essential role in cryogenic two-phase heat management systems due to their efficient heat transfer characteristics. Thus, it is worth conducting an in-depth study on microscale condensation characteristics of cryogenic fluids. This paper delves into the flow condensation process of methane in microchannels. A two-dimensional transient model with high accuracy for cryogenic fluids has been developed by combining a self-defined program for the source term of the phase transition model. The model fully considers the boundary layer thickness and accurately explores the mesh accuracy. The complete condensation flow patterns are captured for various vapor quality, mass flux, and wall subcooling degrees. The injection flow is a unique flow regime for condensation in microchannels. The decrease in wall subcooling degree and increase in mass flux leads to the separation point at the neck of the injected flow moving towards the exit, while the annular flow region is expanding and the flow pattern transition is lagging. The mass flux improves the heat transfer coefficient more significantly at high vapor quality. During injection and bubble flow, the wall shear stress and local heat transfer coefficient are subject to bouncing and oscillations, which may induce fluctuations in the upstream annular flow. The prediction performance of six classical heat transfer correlations is evaluated. The results indicate that the Nie et al. correlation has the highest comprehensive prediction accuracy with MRD and MARD of -5.00 % and 15.83 %, respectively.

Estimating Velocity Correlations Using Single Pixel PIV

In this work, we analyze the possibility of determining correlations of turbulent velocity fluctuations from PIV data with improved spatial resolution. The analysis is based on the method presented by Oldenziel et al. (2023), where a joint probability density function of the velocity at two locations is calculated from the single-pixel ensemble correlation for these locations. Synthetic PIV images are used to discuss the occurrence of random and systematic errors and to derive the number of image pairs required for a determination of the correlation coefficient with desired uncertainty, depending on the particle image density. Compared to classical window correlation, the presented method can improve the spatial resolution by about one order of magnitude if a very large number of PIV image pairs are available and/or many statistically independent points with identical flow properties can be used. As an example of application, we show the spatial distribution of a two-point correlation in a compressible turbulent boundary layer flow for a reference point near the wall.

Quantumness of gravitational cat states in correlated dephasing channels

We study the quantumness of gravitational cat states in correlated dephasing channels. Our focus is on exploring how classical correlations between successive actions of a dephasing channel influence the decoherence of two gravitational cats (two qubits) at a thermal regime. The results show that the quantum coherence, local quantum Fisher information, and Bell non-locality can be significantly enhanced by augmenting classical correlations throughout the entire duration when the two qubits pass the channel. However, the gravitational interaction and energy gap between states exhibit intricate impacts on the quantum characteristics of gravitational cats. New features are reported that can be significant for both gravitational physics and quantum information processing.

Strain Determination Using a Global Interpolation Concept Based on Coherence Scanning Interferometry Measurements

BackgroundThe experimental detection of small and large strains requires special approaches of full-field measurement techniques and their evaluation on 3D curved surfaces of components.ObjectivesSince classical digital image correlation methods have difficulties with the application of paints in some applications, one aim is to use a method in which the surface roughness is used to apply the strain calculation.MethodsIn this paper, 2D digital image correlation is applied to 2D intensity maps extracted from a coherence scanning interferometer together with height information. Height information are used to reconstruct the 3D motion of tracked material points. Surface interpolation and strain calculation are performed using globally formulated radial basis functions.ResultsThe entire procedure leads to an appropriate technique for determining the in-plane strains in curved surfaces of parts, whereas the expected accuracy for various levels of the radial basis functions are discussed in detail.ConclusionsParticularly, coherence scanning interferometry yields highly accurate height information. To smooth the surface motion, it turns out that in particular a regression analysis is required, where we apply radial basis functions with various approximation levels. This is an alternative procedure for surface strain determination.