Determination of Dermal Absorption Qsar/Qsprs by Brute Force Regression: Multiparameter Model Development with Molsuite 2000

2003 ◽  
Vol 66 (20) ◽  
pp. 1927-1942 ◽  
Author(s):  
Richard Moody ◽  
Hart MacPherson
Keyword(s):  
Model Development ◽  
Dermal Absorption ◽  
Brute Force

Performance Testing of Coal Fired Power Plants

2007 ◽  
Author(s):  
Shane E. Powers ◽  
William C. Wood
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Performance Test ◽  
Model Development ◽  
Performance Testing ◽  
The United States ◽  
Plant Performance ◽  
Cycle Performance ◽  
Test Program

With the renewed interest in the construction of coal-fired power plants in the United States, there has also been an increased interest in the methodology used to calculate/determine the overall performance of a coal fired power plant. This methodology is detailed in the ASME PTC 46 (1996) Code, which provides an excellent framework for determining the power output and heat rate of coal fired power plants. Unfortunately, the power industry has been slow to adopt this methodology, in part because of the lack of some details in the Code regarding the planning needed to design a performance test program for the determination of coal fired power plant performance. This paper will expand on the ASME PTC 46 (1996) Code by discussing key concepts that need to be addressed when planning an overall plant performance test of a coal fired power plant. The most difficult aspect of calculating coal fired power plant performance is integrating the calculation of boiler performance with the calculation of turbine cycle performance and other balance of plant aspects. If proper planning of the performance test is not performed, the integration of boiler and turbine data will result in a test result that does not accurately reflect the true performance of the overall plant. This planning must start very early in the development of the test program, and be implemented in all stages of the test program design. This paper will address the necessary planning of the test program, including: • Determination of Actual Plant Performance. • Selection of a Test Goal. • Development of the Basic Correction Algorithm. • Designing a Plant Model. • Development of Correction Curves. • Operation of the Power Plant during the Test. All nomenclature in this paper utilizes the ASME PTC 46 definitions for the calculation and correction of plant performance.

Heuristic determination of the cosmological constant

2021 ◽  
pp. 2150114
Author(s):  
Manuel Urueña Palomo ◽  
Fernando Pérez Lara
Keyword(s):  
Field Theory ◽  
Energy Density ◽  
Cosmological Constant ◽  
Accelerated Expansion ◽  
Fundamental Constants ◽  
Quantum Field ◽  
Brute Force ◽  
Expansion Of The Universe ◽  
The Universe

The vacuum catastrophe results from the disagreement between the theoretical value of the energy density of the vacuum in quantum field theory and the estimated one observed in cosmology. In a similar attempt in which the ultraviolet catastrophe was solved, we search for the value of the cosmological constant by brute-force through computation. We explore combinations of the fundamental constants in physics performing a dimensional analysis, in search of an equation resulting in the measured energy density of the vacuum or cosmological constant that is assumed to cause the accelerated expansion of the universe.

scholarly journals Modeling of diversification of foreign economic interactions

2018 ◽  
Vol 16 (1) ◽  
pp. 155-165
Author(s):  
Ihor Hroznyi ◽  
Oleh Kuzmak ◽  
Olena Kuzmak ◽  
Olha Rusinova
Keyword(s):  
Dynamic System ◽  
Simulation Model ◽  
Mutual Influence ◽  
Model Development ◽  
Complex Dynamic ◽  
Complex Dynamic System ◽  
World Markets ◽  
Economic Interactions ◽  
Simulation Package

The article developed a basic simulation model of diversification of foreign economic interactions, which makes it possible to assess the mutual influence of key economic indicators and their reaction to changes in the equilibrium in world markets. The peculiarity of the developed model of diversification of foreign economic interactions is its functioning as a complex dynamic system in which many factors are interrelated, and the connections are dynamic. This makes it possible to calculate a simulation model that takes into account hidden and subtle connections. While modeling foreign economic interactions and evaluating the influence of various regulators on them, in addition to the stage of model development itself, mandatory parameterization of this model is proposed, that is, the determination of specific types of dependence between the factors included in the model and the parameters of these dependencies. The implementation of this model can be carried out in any simulation package.

Borrowing external information to estimate angler size selectivity: model development and application to Murray cod

2020 ◽  
Vol 77 (2) ◽  
pp. 425-437
Author(s):  
Daniel C. Gwinn ◽  
Gavin Butler ◽  
Brett Ingram ◽  
Scott Raymond ◽  
Mark Lintermans ◽  
...  
Keyword(s):  
Model Development ◽  
External Information ◽  
Size Selectivity ◽  
Large Size ◽  
Data Limitations ◽  
Vulnerability Model ◽  
Selectivity Model ◽  
Murray Cod ◽  
Modelling Approach

Estimating the size selectivity of fishery users and sampling methods can be difficult to achieve due to data limitations. However, these limitations can be moderated by borrowed information from other sources such as other systems, times, and species. Here we develop a model that integrates an externally sourced boat electrofishing length–vulnerability model with internally sourced boat electrofishing and angling catch data to estimate length-dependent vulnerability of fish to angling in a data-limited situation. We apply the model to Murray cod (Maccullochella peelii) as an example and show that angling for Murray cod selectively captures a narrow range of sizes that includes medium to large size fish. Although boat electrofishing also followed a similar pattern, the range of fish sizes vulnerable to capture was much broader, including a more uniform vulnerability of all size classes evaluated. Understanding the length selectivity to capture has key implications for effective determination of fisheries regulations, as well as interpreting monitoring data. Thus, we see this modelling approach as a good option when more informative data are not available to support the estimation process.

Solution of Pavement Deterioration Equations by Genetic Algorithms

2000 ◽  
Vol 1699 (1) ◽  
pp. 101-106 ◽  
Author(s):  
A. Raja Shekharan
Keyword(s):  
Genetic Algorithms ◽  
Model Development ◽  
Complex Model ◽  
Predictor Variables ◽  
Easy Task ◽  
Advantages And Disadvantages ◽  
Pavement Deterioration ◽  
High Degree ◽  
The Relationship

Pavement deterioration models are indispensable for many purposes; as a result, a number of models are in use. Models with simple equation forms are easier to use, but frequently such models may not suffice for many purposes. Consequently, complex nonlinear forms of models are to be considered. However, determination of the solution to a complex model form is not an easy task. There are various methods of obtaining solutions to such models, with each method having its own advantages and disadvantages. The use of genetic algorithms for model development is examined in this study. A very brief description of genetic algorithms is included, and their application for the development of a model is illustrated. Five models of varied complexities, extracted from the literature, are employed to create databases in which the relationship between the response and the predictor variables is known. The solutions to the models are developed employing genetic algorithms. The results indicate a high degree of accuracy, which suggests that genetic algorithms are useful as a tool for development of solutions to pavement deterioration models.

Extensible-Link Kinematic Model for Characterizing and Optimizing Compliant Mechanism Motion

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Justin Beroz ◽  
Shorya Awtar ◽  
A. John Hart
Keyword(s):  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Kinematic Model ◽  
Model Development ◽  
Taylor Series Expansion ◽  
Analytical Determination ◽  
Motion Trajectory ◽  
Model Framework ◽  
Error Components

We present an analytical model for characterizing the motion trajectory of an arbitrary planar compliant mechanism. Model development consists of identifying particular material points and their connecting vectorial lengths in a manner that represents the mechanism topology; whereby these lengths may extend over the course of actuation to account for the elastic deformation of the compliant mechanism. The motion trajectory is represented within the model as an analytical function in terms of these vectorial lengths, whereby its Taylor series expansion constitutes a parametric formulation composed of load-independent and load-dependent terms. This adds insight to the process for designing compliant mechanisms for high-accuracy motion applications because: (1) inspection of the load-independent terms enables determination of specific topology modifications that reduce or eliminate certain error components of the motion trajectory; and (2) the load-dependent terms reveal the polynomial orders of principally uncorrectable error components in the trajectory. The error components in the trajectory simply represent the deviation of the actual motion trajectory provided by the compliant mechanism compared to the ideally desired one. A generalized model framework is developed, and its utility demonstrated via the design of a compliant microgripper with straight-line parallel jaw motion. The model enables analytical determination of all geometric modifications for minimizing the error trajectory of the jaw, and prediction of the polynomial order of the uncorrectable trajectory components. The jaw trajectory is then optimized using iterative finite elements simulations until the polynomial order of the uncorrectable trajectory component becomes apparent; this reduces the error in the jaw trajectory by 2 orders of magnitude over the prescribed jaw stroke. This model serves to streamline the design process by identifying the load-dependent sources of trajectory error in a compliant mechanism, and thereby the limits with which this error may be redressed by topology modification.

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