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Artykuły w czasopismach na temat "Restrictive correlation Model"
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Guo, Jianqiao, Yang Sun, Yunxia Hao, Ligang Cui i Gexue Ren. "A mass-flowing muscle model with shape restrictive soft tissues: correlation with sonoelastography". Biomechanics and Modeling in Mechanobiology 19, nr 3 (18.12.2019): 911–26. http://dx.doi.org/10.1007/s10237-019-01260-z.
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McAleer, Michael, Felix Chan, Suhejla Hoti i Offer Lieberman. "GENERALIZED AUTOREGRESSIVE CONDITIONAL CORRELATION". Econometric Theory 24, nr 6 (9.07.2008): 1554–83. http://dx.doi.org/10.1017/s0266466608080614.
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This paper develops a generalized autoregressive conditional correlation (GARCC) model when the standardized residuals follow a random coefficient vector autoregressive process. As a multivariate generalization of the Tsay (1987, Journal of the American Statistical Association 82, 590–604) random coefficient autoregressive (RCA) model, the GARCC model provides a motivation for the conditional correlations to be time varying. GARCC is also more general than the Engle (2002, Journal of Business & Economic Statistics 20, 339–350) dynamic conditional correlation (DCC) and the Tse and Tsui (2002, Journal of Business & Economic Statistics 20, 351–362) varying conditional correlation (VCC) models and does not impose unduly restrictive conditions on the parameters of the DCC model. The structural properties of the GARCC model, specifically, the analytical forms of the regularity conditions, are derived, and the asymptotic theory is established. The Baba, Engle, Kraft, and Kroner (BEKK) model of Engle and Kroner (1995, Econometric Theory 11, 122–150) is demonstrated to be a special case of a multivariate RCA process. A likelihood ratio test is proposed for several special cases of GARCC. The empirical usefulness of GARCC and the practicality of the likelihood ratio test are demonstrated for the daily returns of the Standard and Poor's 500, Nikkei, and Hang Seng indexes.
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Yue, Yu, Bo Zhang i Zheng Liang Xue. "Study on Desulfurization Kinetics Model of LF Refining". Advanced Materials Research 690-693 (maj 2013): 246–51. http://dx.doi.org/10.4028/www.scientific.net/amr.690-693.246.
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The desulphurization kinetics in ladle refining was analyzed, and the restrictive link for the desulfurization was selected based on previous research. Then the kinetics of desulfurization model in LF refining was developed and the empirical formula of sulfur ratio was summarized. The result by calculated shows that there is a good linear correlation between desulfurization rate and time, and the mass transfer coefficient D=3.79x10-5m/min.
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Cimiotti, Diana, Heidi Budde, Roua Hassoun i Kornelia Jaquet. "Genetic Restrictive Cardiomyopathy: Causes and Consequences—An Integrative Approach". International Journal of Molecular Sciences 22, nr 2 (8.01.2021): 558. http://dx.doi.org/10.3390/ijms22020558.
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The sarcomere as the smallest contractile unit is prone to alterations in its functional, structural and associated proteins. Sarcomeric dysfunction leads to heart failure or cardiomyopathies like hypertrophic (HCM) or restrictive cardiomyopathy (RCM) etc. Genetic based RCM, a very rare but severe disease with a high mortality rate, might be induced by mutations in genes of non-sarcomeric, sarcomeric and sarcomere associated proteins. In this review, we discuss the functional effects in correlation to the phenotype and present an integrated model for the development of genetic RCM.
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Cimiotti, Diana, Heidi Budde, Roua Hassoun i Kornelia Jaquet. "Genetic Restrictive Cardiomyopathy: Causes and Consequences—An Integrative Approach". International Journal of Molecular Sciences 22, nr 2 (8.01.2021): 558. http://dx.doi.org/10.3390/ijms22020558.
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The sarcomere as the smallest contractile unit is prone to alterations in its functional, structural and associated proteins. Sarcomeric dysfunction leads to heart failure or cardiomyopathies like hypertrophic (HCM) or restrictive cardiomyopathy (RCM) etc. Genetic based RCM, a very rare but severe disease with a high mortality rate, might be induced by mutations in genes of non-sarcomeric, sarcomeric and sarcomere associated proteins. In this review, we discuss the functional effects in correlation to the phenotype and present an integrated model for the development of genetic RCM.
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Tsidik, L. I. "CLINICAL VALIDATION OF THE SCALES OF EXPANSIVENESS, RESTRICTIVE CONTROL, CORRECTION AND PHOBIC FEARS OF THE MODIFIED VARIANT OF THE NEUROTIC DISORDERS QUESTIONNAIRE". Journal of the Grodno State Medical University 18, nr 6 (31.12.2020): 681–86. http://dx.doi.org/10.25298/2221-8785-2020-18-6-681-686.
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Background. On the basis of the statements of the questionnaire of neurotic disorders within the framework of the Rush model, which is a kind of modern test theory, 13 scales with proven psychometric properties were formed. This article evaluates the clinical effectiveness of four of them. Purpose of the study. To carry out clinical validation of scales of expansiveness, restrictive control, correction and phobic fears of the modified version of the neurotic disorders questionnaire. Material and methods. A total of 296 people were examined, among them 167 women and 129 men. Statistical methods of research included factor analysis of standardized residuals, ROC-analysis, and correlation analysis. Results. The scales under study have a homogeneous structure. With the help of ROC-analysis, moderate differentiating properties of the scales were revealed, and cutoff values were calculated, which were the criteria for interpretation. Correlation analysis of the total indicator revealed statistically significant correlations between the studied scales and the MMPI scores, the QIDS-SR16 questionnaire and the Hamilton Anxiety Rating Scale (HADS). Conclusions. The scales of expansiveness, restrictive control, correction and phobic fears of the modified version of the neurotic disorders questionnaire are clinically valid and can be used to solve various practical problems.
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Cao, Shulei, Maria Dainotti i Bharat Ratra. "Standardizing Platinum Dainotti-correlated gamma-ray bursts, and using them with standardized Amati-correlated gamma-ray bursts to constrain cosmological model parameters". Monthly Notices of the Royal Astronomical Society 512, nr 1 (24.02.2022): 439–54. http://dx.doi.org/10.1093/mnras/stac517.
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ABSTRACT We show that the Platinum gamma-ray burst (GRB) data compilation, probing the redshift range 0.553 ≤ z ≤ 5.0, obeys a cosmological-model-independent three-parameter Fundamental Plane (Dainotti) correlation and so is standardizable. While they probe the largely unexplored z ∼ 2.3–5 part of cosmological redshift space, the GRB cosmological parameter constraints are consistent with, but less precise than, those from a combination of baryon acoustic oscillation (BAO) and Hubble parameter [H(z)] data. In order to increase the precision of GRB-only cosmological constraints, we exclude common GRBs from the larger Amati-correlated A118 data set composed of 118 GRBs and jointly analyse the remaining 101 Amati-correlated GRBs with the 50 Platinum GRBs. This joint 151 GRB data set probes the largely unexplored z ∼ 2.3–8.2 region; the resulting GRB-only cosmological constraints are more restrictive, and consistent with, but less precise than, those from H(z) + BAO data.
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Lebedev, Valery V., i Konstantin V. Lebedev. "On Assessing the Impact of Coronavirus Epidemic in Russia on Population Incomes". Economics of Contemporary Russia, nr 1 (29.03.2021): 116–33. http://dx.doi.org/10.33293/1609-1442-2021-1(92)-116-133.
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The paper discusses an approach to assessing the impact of the coronavirus epidemic in Russia on economic efficiency and, as a result, on the monetary income of the country's population. The approach used is based on the application of the methodology of mathematical modeling. Based on the analysis of statistical information, it is shown that there is a correlation between the dynamics of the average per capita income of the population and GDP. To assess the dynamics of GDP, a dynamic model of the impact of restrictive measures aimed at curbing the spread of the coronavirus epidemic on macroeconomic efficiency is constructed. The main hypothesis of the model is that the main factor affecting the efficiency of the economy is the productivity of workers who create GDP. In the constructed model, all employees are divided into three groups. The first group – workers whose activities were not affected by the coronavirus; the second group-workers whose productivity decreased due to the coronavirus; the third group-workers whose productivity fully or partially recovered after the easing of restrictive measures. As a result, the dynamics of GDP is determined by a system of three ordinary differential equations with parameters depended on the epidemiological situation. To assess the indicators that characterize the spread of infection and affect the parameters of the macroeconomic efficiency model, a discrete modification of the classical SIR-model of the epidemic with piecewise constant parameters is constructed. This model allowed us to estimate the dynamics of the average for the four day values of the basic reproductive numbers and other indicators of spread of infection through the use of official statistical information in the base period, and to perform scenario calculations for the development of the epidemic in Moscow and beyond until July 2021 Developed modification of the SIR model allows for its clarification with regard to the influence of vaccination on the dynamics of epidemiological process.
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Knezevic, Aleksandar, i Vera Gligorijevic. "The ethno-demographic context of declining birth rates and birth control in Eastern Serbia - an example of an atypical demographic transition". Bulletin de l'Institut etnographique 71, nr 1 (2023): 267–98. http://dx.doi.org/10.2298/gei2301267k.
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The restrictive reproductive model in Eastern Serbia, which appeared in pre- industrial rural society and without of sufficient development potential that would lead to the redefinition of ethical and general social norms, was in many ways similar to industrialized and urbanized societies. The expansive spread of the restricted model of reproduction was atypical in relation to the verme, place and conditions in which it appeared, and beyond all the theoretical postulates of the demographic transition. The paper analyzes the dynamics of change in both components of the natural population movement at the end of the 19th and the beginning of the 20th century and considers the ethnodemographic, ecocultural and socioeconomic context of birth and mortality, which interrelationship indicates the stages of the demographic transition. In addition to objective problems related to the quality of statistical data, the regional demographic differentiation of changes in birth mortality rates indicates a certain correlation between the intensity of the decline in birth and the ethnic structure of the population.
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Bozo, N. V., i O. T. Shipkova. "Interregional Differentiation and Heterogeneity of the Consequences of Pandemic Restrictions in Russia". Voprosy statistiki 30, nr 2 (16.04.2023): 43–52. http://dx.doi.org/10.34023/2313-6383-2023-30-2-43-52.
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The purpose of the study is to analyze the features of the economic development of Russian regions under the influence of various socio-economic factors and the differentiation of region groups depending on the implementation of state regulation of economic activity measures in them during the pandemic period. The analysis was carried out using statistical methods (primarily methods of statistical groupings and correlation-regression analysis). The conceptual and methodological principles for assessing changes in economic activity in Russian regions after the introduction of restrictive measures of different levels of severity are outlined based on the study of Russian and foreign scientific publications on the issues under consideration. A regression model uses to identify the influence of the studied factors. To identify the impact of the studied factors, the authors built a regression model that included the following statistical indicators: index of industrial production, unemployment rate, share of the urban population, share of the region's gross value added (GVA), number of small and medium-sized enterprises (excluding micro-enterprises) per 10,000 population, share of the region in the production of all Russian mining enterprises, region openness coefficient, average per capita monetary income of the population, poverty level. The final part of the article presents the results of the study indicating that pandemic restrictions, depending on the degree of their severity, had a different impact on the economy of the regions. The authors emphasize the heterogeneity of changes in the factors determining the economic activity of regions under the influence of restrictive measures on the part of governments, particularly regional authorities.
Części książek na temat "Restrictive correlation Model"
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Autschbach, Jochen. "Many-electron Systems and the Pauli Principle". W Quantum Theory for Chemical Applications, 109–27. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190920807.003.0007.
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It is shown how the quantum Hamiltonian for a general molecule is set up, using the ‘quantum recipe’ of chapter 3. In the most restrictive Born Oppenheimer approximation, the nuclei are held fixed and the Schrodinger equation (SE) is set up for the electrons only. The wavefunction depends on the positions and spin projections of all electrons. The electron spin projection is introduced heuristically as another two-valued electron degree of freedom. The electronic SE cannot be solved exactly, and (spin-) orbitals are introduced to construct an approximate wavefunction. The Pauli principle demands that a many-electron wavefunction is antisymmetric upon the exchange of electron labels, which leads to the construction of the approximate orbital-model wavefunction as a Slater determinant rather than a simple Hartree product. The orbital model wavefunction does not describe the Coulomb electron correlation, but it incorporates the (Fermi) correlation leading to the Pauli exclusion.
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Bidese, Ermenegildo, Andrea Padovan i Alessandra Tomaselli. "Rethinking Verb Second and Nominative case assignment". W Rethinking Verb Second, 575–93. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198844303.003.0024.
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Cimbrian is a German(ic) VO heritage language that does not display the linear V2 restriction: the DP subject can show up before the finite verb together with other constituents, while German-like verb-subject inversion only obtains with clitic pronouns. In recent literature on Cimbrian, pronominal subject inversion has been taken as a traditional argument in favour of mandatory V-to-C movement (assuming a split-C configuration). Building on this assumption, the syntax of the enclitic expletive subject, -da/-ta, (which shows up whenever the DP subject does not raise in the C-domain) makes the Cimbrian data particularly relevant, since it casts light on the correlation between V2 and Nominative case licensing. The stance in this chapter is that Nominative case in Cimbrian is assigned by C—as generally assumed for Germanic V2 languages—but in an idiosyncratic way: (i) it applies within the C domain, i.e. FinP; (ii) expletive -da/-ta absorbs Nominative case and acts as a defective goal with respect to the ‘low’ subject. On the basis of the feature-spreading model in Ouali (2008), the phasal head C in Cimbrian is taken to ‘KEEP’ its relevant ϕ- and T-features, to assign Nominative case in [Spec,FinP], and to triggering mandatory V-movement.
Streszczenia konferencji na temat "Restrictive correlation Model"
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Stratila, Alina, i Ina Gumeniuc. "Prospects for growth in labor productivity of construction personnel after the Covd pandemic 19". W 4th Economic International Conference "Competitiveness and Sustainable Development". Technical University of Moldova, 2022. http://dx.doi.org/10.52326/csd2022.20.
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The serious economic consequences of the COVD 19 pandemic are reflected in all activities of the national economy of the Republic of Moldova, including construction. In 2020, the activity of construction enterprises is characterized by a slowdown in the growth rate of sales revenues, a reduction in net profits, and a decrease in the average number of employees. Reaching the level of key economic indicators achieved by construction enterprises before the pandemic requires time and significant production stimulation. The key factor for the long-term development of enterprises is still the personnel and its productivity. The article assesses the use of personnel of construction enterprises for the period 2015-2020, including the period of restrictive measures during the first wave of COVD 19. Various quantitative and qualitative aspects of personnel use are considered: personnel mobility, personnel training, working conditions and remuneration, and labor productivity. A multifactor correlation model was elaborated, which allows for a comprehensive approach to the study of personnel productivity by including a wide range of economic indicators of personnel utilization in the regression equation. Measuring the degree of correlation between the effect of the time factor on the economic indicators included in the model allowed to reasonably forecast the expected level of labor productivity in the short term. The increase in labor productivity in 2022 can be 15% compared to the level of the indicator in 2020. The use of the obtained correlation model, covering comprehensively various aspects of the use of enterprise personnel, allows to simulate the desired level of labor productivity, which ensures the reduction of the recovery period of construction enterprises after the pandemic. The practical application of the model is recommended to the interested persons, managing construction enterprises.
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Villedieu, Philippe, i Olivier Simonin. "Kinetic Modeling and Monte-Carlo Simulations of Droplet Coalescence in a Turbulent Gas Flow". W ASME 2002 Joint U.S.-European Fluids Engineering Division Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/fedsm2002-31385.
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Two-phase gas-droplet flows are involved in a lot of industrial applications, especially in the combustion field (Diesel engine, turbomachinery, rocket engine,…). Among all the characteristics of the spray, the droplet size distribution generally has a major influence on the global performances of the system and must be accurately taken into account in a numerical simulation code. This is a difficult task because the carrier gas flow is very often turbulent. Hence, droplets located in the vicinity of the same point may have different velocities and coalesce, leading at the end to a strong modification of the initial droplet size distribution. The first part of our contribution will be devoted to the presentation of a new kinetic model for droplet coalescence in turbulent gas flows. This model is an extension, to the case of sprays, of the ideas introduced by Simonin, Deutsch and Lavie´ville in [1]. The key ingredient is the use of the “joint density function”, fgp (t, x, r, v, u), representing the density of droplets at time t, located at point x, with radius r and velocity v and “viewing” an instantaneous turbulent gas velocity u. The great advantage of using fgp (t, x, r, v, u) instead of the usual density function fp (t, x, r, v) is the possibility to close the collision operator, in the governing kinetic equation, with less restrictive assumptions on the velocity correlations of two colliding droplets. The link between this model and the usual one (relying on the so-called “chaos assumption”) will be discussed. In the second part of our contribution, we shall present a new Monte-Carlo algorithm derived from our kinetic model. Numerical simulation results, for some academic test cases (homogeneous isotropic turbulence), will be shown and compared to the results obtained with a classical algorithm for droplet collision, based on the chaos assumption (see for example [2] or [3]). The figure 1 below shows a comparison between the temporal evolution of the mass mean radius computed by a classical collision model (neglecting the influence of gas and droplet velocity correlation) and by the “joint-pdf” based model. In the first case, the growth rate of the droplet, due to coalescence phenomena, is overestimated. Moreover, figure 2 shows that the droplet kinetic energy, induced by the turbulent gas motion, decays rapidly with the chaos assumption based model, as already noticed by Lavie´ville et al [1] in the case of solid particle collisions.
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Kusano, Shunichi, Konstantinos P. Papathanassiou i Motoyuki Sato. "Volume scattering power restriction based on correlation coefficients for polarimetric SAR model-based decompositions". W IGARSS 2012 - 2012 IEEE International Geoscience and Remote Sensing Symposium. IEEE, 2012. http://dx.doi.org/10.1109/igarss.2012.6352267.
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Kumar, Saket, Sandarbh Gautam, Nitu Kumari Thakur, Murtaza Ahmed Khan i Sikandar Kumar. "A Data Driven P-V-T Model to Predict the Oil Formation Volume Factor, Solution GOR and Bubble Point Pressure for Characterizing an Oil Reservoir". W SPE Reservoir Characterisation and Simulation Conference and Exhibition. SPE, 2023. http://dx.doi.org/10.2118/212600-ms.
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Abstract Characterizing an oil reservoir requires one to understand the Pressure- Volume-Temperature (PVT) properties of reservoir fluids, especially bubble point pressure, solution gas oil ratio and oil formation volume factor because of its more often utilization in reservoir engineering studies. The current correlations are restricted by the use of sample from a particular field. As the physical properties and the composition of the crude oil varies the results becomes erroneous after a specific range. This correlation will give results only over a specific range of properties like specific gravity, viscosity, composition etc. The challenge is to develop a new approach which overcomes the current shortcomings. In this paper a new machine learning based model has been developed using Interactive Multivariate Linear Regression (I-MLR) method by integrating a large number of datasets to predict above mentioned properties. It overcomes the restriction of the previous correlations as it does not use data from any particular field. As such it is applicable over wide range of physical properties and composition. This model does not require any laboratory studies which makes it more economical. The validation of the model is done after detailed comparative study done with various commercially used empirical correlations.
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Gebreegziabher, T., E. Ayorinde i T. Singh. "Detection and Characterization of Pulsatile Flow Induced Acoustic Emissions in Stenosed Arterial Geometric Models". W ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-39914.
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A Newtonian fluid is used in a simplified experimental hydraulic model of a cardiovascular system (CVS) to study pulsatile flow in arterial geometric models with different stages of stenosis (restriction rates) and understand the progression of stenosis and how the fluid flow properties in stenosed sections of arteries behave. In this study, 16mm long cylindrical stenosis models (orifices) with different restriction rates were pressed into the middle section of a 570 mm long arterial geometric model (polyethylene tube) one at a time. The arterial geometric models were connected to a solenoid or reciprocating pump (DC Voltage) capable of generating pulsatile flow at different pumping frequencies. The effects of pulsatile flow properties (pressure pulse, flow rate, etc) on acoustic emission (AE) signal levels using sensors for the detection of elastic waves in the arterial models for different restriction rates of stenoitic geometric models (orifices) at different pumping frequencies have been investigated. The results from this research show that there is a strong correlation between the flow properties of the Newtonian fluid in the arterial geometric models and the level of the flow induced AE signal indicators such as the waveforms, elastic energy, number of events, etc. Thus, as AE techniques can be used to predict flow characteristics in a given geometric model to assess the restriction level of a flow passage, the same principle could be applied in the detection of severe atherosclerosis or stenosis in large arteries — human external carotid arteries.
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Miscia, Giuseppe, Enrico Bertocchi, Luca D’Agostino, Andrea Baldini, Enrico Dolcini i Angelo Narducci. "Composite Materials in Automotive: Improving Safety by Refining FEA Correlation". W ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-64564.
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In the last few years, the restrictive safety standards and the need for weight reduction have brought the crashworthiness research to focus on composite materials because of their high energy absortion-to-mass ratio. On the other hand, the possibility of obtaining predictive dynamic FEA models for these new materials is still an open issue: the present work aims at developing a methodology for the characterization of composite materials with particular interest for the head impact simulation. Composite materials behavior, defined through the mathematical models implemented in FEA codes, is very complex and requires a large amount of physical and numerical setting parameters. The majority of these parameters can be obtained by an experimental campaign that involves several kind of different tests. The presented methodology allows to obtain a good numerical-experimental correlation simply performing few tests which emulate the behavior of the component during the head impact event. A software tool based on a genetic optimization technique has been developed in order to determinate automatically the material properties values that guarantee the best numerical-experimental correlation.
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Chavan, Niranjan S., A. Bhattacharya i Kannan Iyer. "Modeling of Two-Phase Flow Instabilities in Microchannels". W ASME 3rd International Conference on Microchannels and Minichannels. ASMEDC, 2005. http://dx.doi.org/10.1115/icmm2005-75048.
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This paper addresses a non-dimensional analytical stability model aimed at predicting the occurrence of flow instabilities at micro-scale. In this context, linear stability model using homogenous flow was considered. Towards that, a linear stability model was developed using perturbation method. A characteristic equation (the response of pressure drop to a hypothetical perturbation in inlet velocity) obtained in this analysis, is shown to be a function of sub-cooling number, Zuber number, Froude number, friction number and inlet and outlet restriction coefficients. Then, a neutral dynamic stability curve is obtained using D-Partition approach. Similarly, static or excursive stability curve is also obtained from the characteristic equation. The derived analytical form for static and dynamic instability threshold is represented in the form of simplified correlations. The experimental data reported by other researchers agree well with these correlations. From the results, it is amply clear that for all practical purposes, two-phase cooling will be unstable. The question to be answered in future is, therefore, whether the oscillations that accompany can be tolerated from the application viewpoint.
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Yan, Jason, Shenwei Zhang, Shahani Kariyawasam, Maria Pino i Taojun Liu. "Validate Crack Assessment Models With In-Service and Hydrotest Failures". W 2018 12th International Pipeline Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/ipc2018-78251.
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Crack or crack-like anomaly is one of the major threats to the safety and structural integrity of oil and gas pipelines. Various assessment models have been developed and used within pipeline industry to predict the burst capacity for pipelines containing longitudinally-oriented surface cracks. These models have different level of conservatism, accuracy, and precision which significantly impacts pipeline operators’ integrity mitigation decisions such as pressure restriction, excavation, and repair, and also lead to different level of safety. This paper compares the accuracy and precision of the most commonly used crack assessment models, i.e. Modified Ln-Sec, CorLAS, API 579 Level 2 and the recent-published PRCI MAT-8 model using in-service and hydrostatic testing failure data. A total number of 12 in-service and 63 hydrostatic test pipe ruptures due to stress corrosion cracking (SCC) with actual burst pressure, material property, and detailed crack size measurements are collected, and used to derive the probabilistic characteristics of the model errors associated with each model. Compared to the burst tests conducted in the laboratory and investigated in other previous studies, the results obtained from in-service and hydrostatic test ruptures are more representative of the real boundary conditions in pipeline operation. All the assumptions and empirical correlations associated with each model are discussed in details. The analysis result suggests that CorLAS is the most accurate model with the least uncertainty (or highest precision). Mitigation activities can be optimized without compromising safety by using the most accurate and precise model.
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Cheng, Ping, Guodong Wang i Xiaojun Quan. "Boiling and Condensation in Microchannels". W ASME 2008 First International Conference on Micro/Nanoscale Heat Transfer. ASMEDC, 2008. http://dx.doi.org/10.1115/mnht2008-52387.
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The characteristics of boiling of water and condensation of steam in a microchannel under heating or cooling conditions are discussed in this paper. Stable and unstable boiling modes occur in a microchannel, depending on the nucleated bubble size in the microchannel. Stable boiling mode with constant temperature variations exists when the size of the nucleated bubble is less than that of the microchannel diameter, while unstable boiling mode exists when the size of the bubble is greater than the microchannel diameter. The latter is owing to the fact that when a bubble grows to the size of the microchannel, it will expand in both upstream and downstream directions. Subsequently, the reversed flow of vapor bubble is swept downstream by the incoming subcooled liquid, leading to large cyclic fluctuations of temperature and pressure. The amplitude and frequency of these fluctuations depend greatly on the inlet/outlet configurations and the exit vapor quality. By fabricating an inlet restriction on each microchannel, the reversed flow of vapor can be suppressed, resulting in a stable flow boiling mode. Boiling heat transfer coefficient and pressure drop in a microchannel under stable flow boiling conditions are obtained. These data at high vapor qualities are found to be substantially different from the correlations obtained for flow boiling in macrochannels. For condensation in a microchannel, mist flow, annular flow, injection flow, slug/bubbly flow exist depending on mass flux, condensation heat flux, and the location in the microchannel. The occurrence of the injection flow is owing to the instability of the liquid/vapor interface because the surface tension effect is predominant in microchannels. The location, at which the injection flow occurs, depends on the mass flux and the cooling rate of steam. Increase in steam mass flux, decrease in cooling rate and the microchannel diameter tend to enhance instability of the condensate film on the wall, resulting in occurrence of the injection flow further toward the outlet with an increase in occurrence frequency. At low mass fluxes, the pressure drop obtained for condensation in microchannels is substantially different from the correlation equations for macrochannels because of different flow patterns.
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Juday, Richard D. "Globally optimal filters". W OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/oam.1992.thpp1.
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A filter calculating algorithm is presented. The algorithm produces filters that are analytically optimal. That is, we show that no filter exceeds this algorithm's performance for the stated metric, noise and signal models, and SLM limitations. It is suitable to a wide variety of performance metrics, including signal-to-noise ratio and correlation sharpness. It explicitly accommodates colored additive input noise of known power spectral density and also detector plane additive noise that may be intensity dependent. The modulator on which the filter is expressed must be known, though (aside from the restriction that it be finite) it is entirely arbitrary. The SLM may be complex, coupled, phase-only, amplitude-only, binary, ternary, or otherwise discrete. It need not be spatially uniform in its action. Finite contrast ratio is accommodated. The algorithm requires a search over no more than two parameters, and conditions that may restrict the search are also presented.