Anti-Optimization Versus Probability in an Applied Mechanics Problem: Vector Uncertainty

2000 ◽  
Vol 67 (3) ◽  
pp. 472-484 ◽  
Author(s):  
M. Zingales ◽  
I. Elishakoff
Keyword(s):  
Smooth Boundary ◽  
Optimization Method ◽  
Rectangular Domain ◽  
Probability Density Functions ◽  
Alternative Methods ◽  
Applied Mechanics ◽  
Mechanical Problem ◽  
Uncertain Variables ◽  
Advantages And Disadvantages ◽  
Probabilistic Setting

In this study probabilistic and nonprobabilistic anti-optimization approaches are contrasted to evaluate their relative advantages and disadvantages while solving a mechanical problem in presence of vector uncertainty. The different cases that are analyzed in probabilistic setting that deal with either uniform or generic probability density functions for the uncertain variables varying in a rectangular domain. This case has been compared with interval analysis, a particular case of anti-optimization. The presence of a convex, smooth boundary of the uncertain domain has been also considered for comparing results obtained with these two alternative methods. It is shown that in case of vector uncertainty the anti-optimization method yields the same solution for the design problem as is provided by means of more complex probabilistic considerations. [S0021-8936(00)03103-2]

Probabilistic Optimal Design Using Successive Surrogate Probability Density Functions

1990 ◽  
Author(s):  
R. J. Eggert ◽  
R. W. Mayne
Keyword(s):  
Probability Density ◽  
Optimization Method ◽  
Probability Density Functions ◽  
Density Functions ◽  
Matching Method ◽  
Design Constraint ◽  
New Approach ◽  
Function Formulation ◽  
The Moment ◽  
Theoretical Considerations

Abstract Probabilistic optimization using the moment matching method and the simulation optimization method are discussed and compared to conventional deterministic optimization. A new approach based on successively approximating probability density functions, using recursive quadratic programming for the optimization process, is described. This approach incorporates the speed and robustness of analytical probability density functions and improves accuracy by considering simulation results. Theoretical considerations and an example problem illustrate the features of the approach. The paper closes with a discussion of an objective function formulation which includes the expected cost of design constraint failure.

Approaches to motion control intellectualization of a mobile robot

2021 ◽  
Author(s):  
Stepan A. Lapshinov ◽  
Vadim A. Shakhnov ◽  
Anton V. Yudin
Keyword(s):  
Mobile Robot ◽  
Motion Control ◽  
Control Device ◽  
Alternative Methods ◽  
Design Solution ◽  
Movement Direction ◽  
Software Complex ◽  
Advantages And Disadvantages ◽  
Drive Control ◽  
Omni Wheel

The paper considers the principles of intelligent motion control of mobile robots using the example of omni-wheel modules. The proposed design solution uses components of movement intelligence in any direction, receiving commands from a human operator or above a standing automatic control device, consisting of an angle of movement direction and the required distance of movement. This paper presents an embodiment of using omni-wheels to move a mobile robot over a flat surface. Features of device and application of drive with three omni-wheels in comparison with differential drive are considered. Kinematics, basic principles of motion control formation, hardware and software complex for its implementation are described. There were revealed two alternative methods of organization of drive control in conditions of shortage of low-level hardware resources on the basis of 8-bit microcontroller, their advantages and disadvantages have been analyzed. Process support and materials have been presented that allows realizing the competitive advantages of development while minimizing the cost of components. Features of mobile robot travel route development have been mentioned on the example of competitive practice.

scholarly journals Opportunities and Questions: A Short Report on Rubric Assessments in Asia and the Middle East

2019 ◽  
Author(s):  
Ronnie Goodwin
Keyword(s):  
Middle East ◽  
Assessment Tool ◽  
Relevant Literature ◽  
Alternative Methods ◽  
Learning Theories ◽  
Short Report ◽  
Rating Systems ◽  
Self Assessment ◽  
Advantages And Disadvantages ◽  
The Impact

This qualitative short report considers the viability of the use of rubrics or alternative methods to assess writing in Asia and the Middle East. The background of learning theories, assessment types, and self-assessment literature provides a foundation for further discussion of the appropriate use of rubrics, including the prioritization of criterion, the quality of scoring, the impact of organizational features on scoring, the influence of bias, and the best application of rubric assessment. Relevant points for further study are identified, such as differentiation in research between generalized analytical rating systems and rubric assessment with specific, empirical criterion. The contradictory research regarding the advantages and disadvantages of rubric assessment in comparison with holistic assessment are of particular and crucial interest for global pedagogy. Many of the reviewed Western articles excluded Asian perspectives- except for China- and thus present a limited understanding of social and educational compatibility with new assessments and rubric assessments in particular. The discussion identifies patterns and points of contention and seeks to explore viewpoints rather than limit the scope of inquiry and consideration thus noting that relevant literature suggests that with appropriate teacher training, teachers may appropriately use rubrics as a formative assessment tool for writing in Asia and the Middle East.

Estimation of the proportion of C3 and C4 plant species in the diet of animals from the ratio of natural 12C and 13C isotopes in the faeces

1979 ◽  
Vol 92 (1) ◽  
pp. 91-100 ◽  
Author(s):  
R. J. Jones ◽  
M. M. Ludlow ◽  
J. H. Troughton ◽  
C. G. Blunt
Keyword(s):  
Time Lag ◽  
Alternative Methods ◽  
C4 Plant ◽  
Advantages And Disadvantages ◽  
C Isotopes ◽  
Tropical Legumes ◽  
C Value ◽  
13C Isotopes ◽  
Definition Of

SummaryThe relation between the ratio of the natural 12C and 13C isotopes of carbon in the feed and resultant faeces of animals was studied to develop a technique for estimating the proportion of C3 species (tropical legumes) and C4 species (tropical grasses) selected by grazing animals.In general, theδ13C values (see text for definition) of faeces from rabbits, sheep, goats and cattle were lower (more negative) than those of the corresponding feeds by from 0·4 to 2·0. This was possibly due to contamination in the gut by tissues or fluids with lower δ13C values. When C4 and C3 feeds were alternated, cattle took about a week to fully achieve the new level (δ13C of – 28·7 on the C3 feed and – 13·1 on the C4 feed) in the faeces. This time lag is associated with the time taken for the feed to move through the digestive tract.When mixed C3 and C4 feeds were fed to rabbits, sheep, goats and cattle there was a negative linear relation between percentage legume (C3) in the feed and the δ13C of the faeces (P < 0·01). A decrease in one unit in the δ13C value was associated with an increase of 7·0–8·5% legume in the diet.Estimation of the percentage legume in the feed from the δ13C value of the faeces and of the C3 and C4 components of the diet, resulted in a consistent over estimation of the legume component because the faeces had lower values than the corresponding feeds. This bias was removed if the prediction was based on the δ13C of the feeds minus 1 unit; the legume percentage in the diets of the sheep, goats and cattle could then be estimated with a precision of about ± 5%.Differences in digestibility between the C3 and C4 components greatly bias the estimations. This bias in the diets fed to rabbits was effectively removed by using in vitro organic matter digestibility values of the two components to correct for the differences. Legume percentage in the diet could then be estimated with a RSD of ± 3%.Advantages and disadvantages compared with alternative methods of estimating the diet of grazing animals are discussed.

Recent advances in measurement of amylase activity--a comparative study.

1980 ◽  
Vol 26 (7) ◽  
pp. 846-853 ◽  
Author(s):  
R A Kaufman ◽  
N W Tietz
Keyword(s):  
Comparative Study ◽  
Amylase Activity ◽  
Alternative Methods ◽  
Advantages And Disadvantages ◽  
Preliminary Discussion ◽  
Recent Advances ◽  
Analytical Range

Abstract We evaluated four kinetic amylase procedures with respect to kinetics, analytical range, blank rates, reagent stability, reagent impurities, interfering substances, and intrinsic sensitivities. Each of the methods is shown to have its own unique advantages and disadvantages. A preliminary discussion of some alternative methods, in which glycosidic p-nitrophenyl alpha-oligosaccharides are substrates, is included.

scholarly journals Estimation of ethylene production and 1-aminocyclopropane-1-carboxylic acid in plants by means of gas chromatography

2008 ◽  
Vol 54 (No. 2) ◽  
pp. 55-60 ◽  
Author(s):  
H. Fišerová ◽  
Z. Mikušová ◽  
M. Klemš
Keyword(s):  
Gas Chromatography ◽  
Carboxylic Acid ◽  
Ethylene Production ◽  
Sampling Procedure ◽  
Alternative Methods ◽  
Time Consumption ◽  
Advantages And Disadvantages ◽  
Endogenous Level ◽  
Extraction And Purification ◽  
And Storage

The paper deals with problems associated with preparation and collection of samples when estimating the production of ethylene and content of ACC (1-aminocyclopropane-1-carboxylic acid) in plants by means of gas chromatography. A proper method of sampling can significantly influence not only the reliability of obtained data but also their interpretation. Attention was paid to cultivation of plant material, sampling vessels, conditions of ethylene production, sampling procedure, and storage of gaseous samples. The estimation of ACC as a precursor of ethylene is more laborious but it supplements the information about the endogenous level of ethylene in a given part of the plant organism. The authors describe the sampling procedure, methods of sample preservation, extraction and purification, and also the method of oxidation of ACC to ethylene. In the final part of this study the authors evaluate the time consumption and difficulty of individual methods and describe their advantages and disadvantages as compared with other, alternative methods.

Evaluating the Cost and Effectiveness of Customer Training Methods

1978 ◽  
Vol 22 (1) ◽  
pp. 331-331
Author(s):  
Stephen H. Ellis
Keyword(s):  
Field Studies ◽  
Training Effectiveness ◽  
Alternative Methods ◽  
Training Methods ◽  
Advantages And Disadvantages ◽  
Hands On ◽  
Different Types ◽  
Self Instruction ◽  
The Cost ◽  
Customer Training

The talk will deal with alternative methods of training customers to use new telephone services. Various measures of training effectiveness will be discussed with regard to their advantages and limitations. It will be argued that several measures—including cost—must be taken into account when evaluating training approaches. Two field studies will be described that examine several different types of training: (1) “Hands On” (demonstration) vs. “No Hands On” training; (2) Media-based vs. Lecture-based training; (3) “Live” training vs. Self-Instruction. The advantages and disadvantages of each approach will be described in terms of several measures of training effectiveness.

A Bayesian Approach to Reliability-Based Optimization With Incomplete Information

2006 ◽  
Author(s):  
Subroto Gunawan ◽  
Panos Y. Papalambros
Keyword(s):  
Incomplete Information ◽  
Piston Ring ◽  
Probability Distributions ◽  
Cylinder Liner ◽  
Optimization Method ◽  
Uncertain Variables ◽  
Additional Information ◽  
Finite Samples ◽  
Estimate Reliability ◽  
Reliability Based Optimization

In engineering design, information regarding the uncertain variables or parameters is usually in the form of finite samples. Existing methods in optimal design under uncertainty cannot handle this form of incomplete information; they have to either discard some valuable information or postulate existence of additional information. In this article, we present a reliability-based optimization method that is applicable when information of the uncertain variables or parameters is in the form of both finite samples and probability distributions. The method adopts a Bayesian Binomial inference technique to estimate reliability, and uses this estimate to maximize the confidence that the design will meet or exceed a target reliability. The method produces a set of Pareto trade-off designs instead of a single design, reflecting the levels of confidence about a design’s reliability given certain incomplete information. As a demonstration, we apply the method to design an optimal piston-ring/cylinder-liner assembly under surface roughness uncertainty.

scholarly journals 3D RECONSTRUCTION FROM MULTI-VIEW MEDICAL X-RAY IMAGES – REVIEW AND EVALUATION OF EXISTING METHODS

2015 ◽  
Vol XL-1-W5 ◽  
pp. 319-326 ◽  
Author(s):  
S. Hosseinian ◽  
H. Arefi
Keyword(s):  
3D Reconstruction ◽  
Imaging Techniques ◽  
Weight Bearing ◽  
Computer Assisted Surgery ◽  
3D Models ◽  
Alternative Methods ◽  
Computer Assisted ◽  
X Ray ◽  
Advantages And Disadvantages ◽  
Reconstruction Methods

The 3D concept is extremely important in clinical studies of human body. Accurate 3D models of bony structures are currently required in clinical routine for diagnosis, patient follow-up, surgical planning, computer assisted surgery and biomechanical applications. However, 3D conventional medical imaging techniques such as computed tomography (CT) scan and magnetic resonance imaging (MRI) have serious limitations such as using in non-weight-bearing positions, costs and high radiation dose(for CT). Therefore, 3D reconstruction methods from biplanar X-ray images have been taken into consideration as reliable alternative methods in order to achieve accurate 3D models with low dose radiation in weight-bearing positions. Different methods have been offered for 3D reconstruction from X-ray images using photogrammetry which should be assessed. In this paper, after demonstrating the principles of 3D reconstruction from X-ray images, different existing methods of 3D reconstruction of bony structures from radiographs are classified and evaluated with various metrics and their advantages and disadvantages are mentioned. Finally, a comparison has been done on the presented methods with respect to several metrics such as accuracy, reconstruction time and their applications. With regards to the research, each method has several advantages and disadvantages which should be considered for a specific application.

scholarly journals Сomparative analysis of the methods of strengthening of masonry, metal structures, reinforced concrete, such as traditional methods and the alternative methods of strengthening by FRP-materials

2020 ◽  
pp. 267-291
Author(s):  
Iryna Rudnieva
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Alternative Methods ◽  
Building Structures ◽  
Traditional Methods ◽  
External Appearance ◽  
Metal Structures ◽  
Advantages And Disadvantages ◽  
Heritage Buildings ◽  
Determining Factor

Built mostly centuries ago, heritage buildings as well the more contemporary buildings of the last century, which have lost the bearing capacity often need restoration and strengthening, especially in seismic regions and in regions with shrinkage phenomena (subsidence region). The need of strengthening of the building constructions during exploitation appears mostly because of their premature wear as a result of technological influences and weathering, various damage and various other factors. Traditional methods of strengthening are effective, but in some cases not appropriate or not applicable  for use. An example is the increase of the load-bearing structures of historical buildings, preserving the external appearance of which is the determining factor. In this case, the use of the discussed alternative methods can be justified alternative. Knowledge of the causes of defects and damage of structures allows to choose the best option of repairing or strengthening. The aim of the research is the evaluation of the structural performance of composite fibre-reinforced elements in the wider sector of the conservation of historical, architectonic and environmental heritage, as well the more contemporary buildings of the last century, which have lost of the bearing capacity focusing reliability indexes and the appearance of the structure. In the article was described and analyzed the existing traditional methods and the alternative methods of strengthening by FRP-materials (composite materials) such building structures as masonry, metal structures, reinforced concrete, and the computation in software ABAQUS. These procedures of strengthening building structures by FRP-materials  in Ukraine are not widely used due to the lack of a regulatory framework that would regulate their use, as well because these materials are relatively expensive compared to the traditional ones. The article analyzed the existing methods of computation and design of the strengthening using FRP-materials, and the computation in software ABAQUS was performed with conclusions and recommendations based on results of the computation. The aim of the work was to review the technology and analyze the advantages and disadvantages of each of the strengthen methods that should be used when choosing effective solutions for strengthening building structures. In conclusion, the need for further study and researches was confirmed.

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