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Two- and three-dimensional dynamic acoustothermography is carried out in model experiments. The. temperature of the model plasticine objects was determined from the measurements of their thermal acoustic radiation in the course of...
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Two- and three-dimensional dynamic acoustothermography is carried out in model experiments. The. temperature of the model plasticine objects was determined from the measurements of their thermal acoustic radiation in the course of their heating and cooling. The measurements were performed with the use of a planar array of 14 acoustothermometers and two planar arrays perpendicular to each other with 7 acous-tothermometers in each of them. The results of measurements were used to plot a dynamic map of the tem-perature of acoustic brightness and to reconstruct the dynamics of variations in the parameters of the temper-ature distribution: the spatial coordinates of the heated region, its characteristic size and, maximal tempera-ture. The duration of one measurement cycle was 10 s, the error in determining the position of the center and the size of the heated region did not exceed 1 mm, and the accuracy of the temperature's calculation was about 1 degree. The results of the Study may be used for controlling the temperature in the course of medical procedures that include heating of internal tissues in human patients.
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Model development is a successive process of validating, revising, and extending models, and requires iterative execution of simulation experiments. While developing a model by extension, executing similar simulation experiments t...
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Model development is a successive process of validating, revising, and extending models, and requires iterative execution of simulation experiments. While developing a model by extension, executing similar simulation experiments to those performed with the original model reveals important behavioral insights into the extended model. An automatic generation and execution of these simulation experiments can provide valuable support in the process of developing models. A prerequisite is an explicit specification of simulation experiments. Therefore, we annotate models with simulation experiments that are specified in a declarative domain specific language SESSL (Simulation Experiment Specification via a Scala Layer). Based on experiment specifications of the original model, we introduce a mechanism to automatically generate and execute simulation experiments for the extended model with necessary adaptations. Furthermore, as we experiment with stochastic models, we exploit statistical model checking and specify the expected model behavioral properties, against which the simulation results are checked. Thereby, when a model is extended, the original experiment specifications are reused, adapted, and applied to the extended model. Accordingly, the generated simulation trajectories are probed to check whether the expected properties hold with a certain probability or not. Thus, more fast and frequent feedback during model development can be provided to the modeler. Based on a model of membrane related dynamics, we show how the developed approach can be used in successively extending models. (C) 2016 Elsevier B.V. All rights reserved.
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Strauch and Murray have been the first to report the free transfer of the epigastric skin flap, and they described it on the ventral abdominal skin of the rat, with a size of 6 X 3 cm. Many other authors have followed to report a ...
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Strauch and Murray have been the first to report the free transfer of the epigastric skin flap, and they described it on the ventral abdominal skin of the rat, with a size of 6 X 3 cm. Many other authors have followed to report a number of variations and modifications. The experimental free transfer of this flap is usually to the ipsilateral or contralateral inguinal region. Later on, transfers to different locations like the axillary region were reported.
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Most hospitality research has treated the concept of service quality as an entity unto itself That is, it has been studied in isolation or as a precursor variable for satisfaction. In the era of the experience economy, however, se...
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Most hospitality research has treated the concept of service quality as an entity unto itself That is, it has been studied in isolation or as a precursor variable for satisfaction. In the era of the experience economy, however, service quality must beintegrated into a holistic model built on the notion of a guest's experience. Thus, this article proposes an integrated, threephase model structured to incorporate service quality as a major component of the experience construct. While speculation aboutwhat constitutes a hospitality experience abound, the complex relationship among value, service quality, satisfaction, and experience is in its infancy. Before this relationship can be fully examined, dimensions of these four critical components need tobe incorporated into a unified, holistic model that includes the four primary constructs of service quality, value, satisfaction, and experience. This article focuses on this initial challenge.
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Experimentation is traditionally considered a privileged means of confirmation. However, why and how experiments form a better confirmatory source relative to other strategies is unclear, and recent discussions have identified exp...
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Experimentation is traditionally considered a privileged means of confirmation. However, why and how experiments form a better confirmatory source relative to other strategies is unclear, and recent discussions have identified experiments with various modeling strategies on the one hand, and with 'natural' experiments on the other hand. We argue that experiments aiming to test theories are best understood as controlled investigations of specimens. 'Control' involves repeated, fine-grained causal manipulation of focal properties. This capacity generates rich knowledge of the object investigated. 'Specimenhood' involves possessing relevant properties given the investigative target and the hypothesis in question. Specimens are thus representative members of a class of systems, to which a hypothesis refers. It is in virtue of both control and specimenhood that experiments provide powerful confirmatory evidence. This explains the distinctive power of experiments: although modelers exert extensive control, they do not exert this control over specimens; although natural experiments utilize specimens, control is diminished.
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Process-aware information systems (PAISs) is a special class of information systems intended to support the tasks of initialization, end-to-end management, and completion of business processes. During their operation such systems ...
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Process-aware information systems (PAISs) is a special class of information systems intended to support the tasks of initialization, end-to-end management, and completion of business processes. During their operation such systems accumulate a large amount of data that are stored in the form of event logs. Event logs are a valuable source of knowledge about the actual behavior of a system. For example, they include (i) information about the discrepancy between the real and prescribed behavior of the system, (ii) information for identifying the bottlenecks and performance issues, and (iii) information for detecting the antipatterns of building a business system. These problems are studied in the discipline called process mining. The practical application of the process mining methods and practices is carried out using specialized software for data analysts. The subject area of the process analysis involves the work of an analyst with a large number of graphical models. Such work can be more efficiently with a convenient graphical modeling tool. This paper discusses the principles of designing a graphical tool VTMine for Visio for process modeling, based on the widespread application Microsoft Visio for business intelligence. The features of the architecture design of the software extension for application in the process mining area are presented along with the features of integration with existing libraries and tools for working with data. The usage of the developed tool for solving various types of tasks in modeling and analysis of processes is demonstrated on a set of experimental schemes.
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Steady-state free precession (SSFP) has recently been proposed for function MRI because of the potential for reducing image distortion and signal dropout. Several different contrast mechanisms have been suggested to explain the re...
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Steady-state free precession (SSFP) has recently been proposed for function MRI because of the potential for reducing image distortion and signal dropout. Several different contrast mechanisms have been suggested to explain the reported observations, but there has been limited work comparing theory with experiment in the brain. Moreover, the detailed work that has considered oxygen-dependent signal in SSFP outside the brain has focused on R(2) effects in the pass band, and largely neglected the signal contrast that occurs due to off-resonance effects. The article describes a model for SSFP functional contrast based on the convolution of the theoretical SSFP profile with the underlying frequency distribution. It is demonstrated that such a model must account for the effects of diffusion, which can alter the apparent R(2) and linespread. Monte Carlo simulations are used to calibrate corrections for these terms. This new model has the computational efficiency of the convolution model while encapsulating information from more time-consuming Monte Carlo simulations. This corrected convolution model is shown to agree well with experimental data, and model predictions and limitations are discussed.
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Modeling the effects of clinical magnetization transfer (MT) scans, which generate contrast using short, shaped radiofrequency (RF) pulses (pulsed MT), is complex and time-consuming. As a result, several studies have proposed appr...
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Modeling the effects of clinical magnetization transfer (MT) scans, which generate contrast using short, shaped radiofrequency (RF) pulses (pulsed MT), is complex and time-consuming. As a result, several studies have proposed approximate methods for a simplified analysis of the experimental data. However, potential differences in the MT parameters estimated by each method may complicate the comparison of reported results. In this study we evaluated three approximate methods currently used in quantitative MT (qMT) studies. In the first part of the investigation, an MT modeling technique that makes minimal approximations, other than the use of a two-pool tissue representation, was developed and validated. Subsequently, this technique served as a standard against which to evaluate the other, more approximate models. Each model was used to fit experimental data from samples of wild-type (WT) and shiverer mouse spinal cord, as well as simulated data generated by our minimal approximation modeling technique.The results of this study demonstrate that the approximations used in pulsed MT modeling are quite robust. In particular, it was shown that the semisolid pool fraction, M(0)(B), which is known to correlate strongly with myelin content, and the transverse relaxation time of macromolecular protons, T(2)(B), could be evaluated with reasonable accuracy regardless of the model used.
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Developmental processes in complex animals are directed by a hardwired genomic regulatory code, the ultimate function of which is to set up a progression of transcriptional regulatory states in space and time. The code specifies t...
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Developmental processes in complex animals are directed by a hardwired genomic regulatory code, the ultimate function of which is to set up a progression of transcriptional regulatory states in space and time. The code specifies the gene regulatory networks (GRNs) that underlie all major developmental events. Models of GRNs are required for analysis, for experimental manipulation and, most fundamentally, for comprehension of how GRNs work. To model GRNs requires knowledge of both their overall structure, which depends upon linkage amongst regulatory genes, and the modular building blocks of which GRNs are heirarchically constructed. The building blocks consist of basic transcriptional control processes executed by one or a few functionally linked genes. We show how the functions of several such building blocks can be considered in mathematical terms, and discuss resolution of GRNs by both "top down" and bottom up
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The combined use of experimental and mathematical models can lead to a better understanding of fracture healing. In this study, a mathematical model, which was originally established by Bailon-Plaza and van der Meulen (J Theor Bio...
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The combined use of experimental and mathematical models can lead to a better understanding of fracture healing. In this study, a mathematical model, which was originally established by Bailon-Plaza and van der Meulen (J Theor Biol 212:191-209, 2001), was applied to an experimental model of a semi-stabilized murine tibial fracture. The mathematical model was implemented in a custom finite volumes code, specialized in dealing with the model's requirements of mass conservation and non-negativity of the variables. A qualitative agreement between the experimentally measured and numerically simulated evolution in the cartilage and bone content was observed. Additionally, an extensive parametric study was conducted to assess the influence of the model parameters on the simulation outcome. Finally, a case of pathological fracture healing and its treatment by administration of growth factors was modeled to demonstrate the potential therapeutic value of this mathematical model.
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