Defenses Against Design Constraint Based Attacks

2021 ◽  
pp. 63-104
Author(s):  
Ranga Vemuri ◽  
Suyuan Chen
Keyword(s):  
Design Constraint

Research on the application of 3D reconstruction technology in traditional handicraft design

2021 ◽  
pp. 002072092110052
Author(s):  
GuoLong Zhang
Keyword(s):  
Poisson Equation ◽  
Optimization Algorithm ◽  
Three Dimensional ◽  
Reconstruction Algorithm ◽  
Social Production ◽  
Design Constraint ◽  
Reconstruction Process ◽  
Key Steps ◽  
Shielding Design ◽  
Reconstruction Model

The use of computer technology for three-dimensional (3 D) reconstruction is one of the important development directions of social production. The purpose is to find a new method that can be used in traditional handicraft design, and to explore the application of 3 D reconstruction technology in it. Based on the description and analysis of 3 D reconstruction technology, the 3 D reconstruction algorithm based on Poisson equation is analyzed, and the key steps and problems of the method are clarified. Then, by introducing the shielding design constraint, a 3 D reconstruction algorithm based on shielded Poisson equation is proposed. Finally, the performance of two algorithms is compared by reconstructing the 3 D image of rabbit. The results show that: when the depth value of the algorithm is 11, the surface of the rabbit image obtained by the proposed optimization algorithm is smoother, and the details are more delicate and fluent; under different depth values, with the increase of the depth value, the number of vertices and faces of the two algorithms increase, and the optimal depth values of 3 D reconstruction are more than 8. However, the proposed optimization algorithm has more vertices, and performs better in the reconstruction process; the larger the depth value is, the more time and memory are consumed in 3 D reconstruction, so it is necessary to select the appropriate depth value; the shielding parameters of the algorithm have a great impact on the fineness of the reconstruction model. The larger the parameter is, the higher the fineness is. In a word, the proposed 3 D reconstruction algorithm based on shielded Poisson equation has better practicability and superiority.

scholarly journals Low Power Digital Multimedia Telecommunication Designs

VLSI Design ◽  
2001 ◽  
Vol 12 (3) ◽  
pp. 301-315 ◽  
Author(s):  
Koon-Shik Cho ◽  
Jun-Dong Cho
Keyword(s):  
Motion Estimation ◽  
Low Power ◽  
Communication Systems ◽  
Matched Filter ◽  
Optimization Technique ◽  
Low Power Design ◽  
Multimedia Systems ◽  
Wireless Multimedia ◽  
Design Constraint ◽  
Power Capability

The increasing prominence of wireless multimedia systems and the need to limit power capability in very-high density VLSI chips have led to rapid and innovative developments in low-power design. Power reduction has emerged as a significant design constraint in VLSI design. The need for wireless multimedia systems leads to much higher power consumption than traditional portable applications. This paper presents possible optimization technique to reduce the energy consumption for wireless multimedia communication systems. Four topics are presented in the wireless communication systems subsection which deal with architectures such as PN acquisition, parallel correlator, matched filter and channel coding. Two topics include the IDCT and motion estimation in multimedia application.These topics consider algorithms and architectures for low power design such as using hybrid architecture in PN acquisition, analyzing the algorithm and optimizing the sample storage in parallel correlator, using complex matched filter that analog operational circuits controlled by digital signals, adopting bit serial arithmetic for the ACS operation in viterbi decoder, using CRC to adaptively terminate the SOVA iteration in turbo decoder, using codesign in RS codec, disabling the processing elements as soon as the distortion values become great than the minimum distortion value in motion estimation, and exploiting the relative occurrence of zero-valued DCT coefficient in IDCT.

What is the Evolutionary Advantage of Migraine?

Cephalalgia ◽  
2002 ◽  
Vol 22 (8) ◽  
pp. 624-632 ◽  
Author(s):  
E Loder
Keyword(s):  
Nervous System ◽  
Natural Selection ◽  
Environmental Factors ◽  
Genetic Factors ◽  
Evolutionary Perspective ◽  
Defence Mechanism ◽  
Design Constraint ◽  
Trade Off ◽  
Evolutionary Advantage ◽  
Evolutionary Explanations

Susceptibility to migraine is determined by genetic factors and is therefore subject to the forces of natural selection. Migraine is a common and ancient disorder whose prevalence may be increasing, suggesting that a migraine-prone nervous system may be associated with reproductive or survival advantages. Five evolutionary explanations are reviewed that might account for the persistence of migraine: (i) migraine as a defence mechanism; (ii) migraine as a result of conflict with other organisms; (iii) migraine as result of novel environmental factors; (iv) migraine as a trade-off between genetic harms and benefits; and (v) migraine as a design constraint. An evolutionary perspective on migraine allows the generation of important hypotheses about the disorder and suggests rewarding possibilities for further research.

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.

Optimization Design of an Axial-Flow Fan Used in Local Ventilation in Mining Industry

2011 ◽  
Author(s):  
Dhaval Desai ◽  
Jiang Zhou
Keyword(s):  
Optimization Design ◽  
Optimization Technique ◽  
Mining Industry ◽  
Axial Flow ◽  
Optimization Method ◽  
Low Noise ◽  
Design Constraint ◽  
Engineering Research ◽  
Blade Element Theory ◽  
Local Ventilation

In a world where the increasing demand on developing energy-efficient systems is probably the most stringent design constraint, the trend in engineering research in recent years has been to optimize the existing technologies rather than to implement new ones. The present work addresses a robust axial-type fan design technique developed using an optimization technique. A fan is indispensable equipment for primary and local ventilation in mining industries. We always pursue the fan with high working efficiency and low noise. In this paper, an optimization method is developed to improve the pneumatic properties of the fan based on the blade element theory. A new type of fan used in local ventilation is designed with the help of computer. It is shown that the new design enhanced the efficient up to 88%. Numerical analysis is also conducted to validate the optimization design results.

scholarly journals CO2 and cost optimization of reinforced concrete footings over a lime-treated soil using modified simulated annealing algorithm

Inge CUC ◽  
2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Jair De Jesús Arrieta Baldovino ◽  
Carlos Millán Páramo ◽  
Ronaldo Luis Dos Santos Izzo ◽  
Eclesielter Moreira
Keyword(s):  
Simulated Annealing ◽  
Co2 Emissions ◽  
Simulated Annealing Algorithm ◽  
Friction Angle ◽  
Curing Time ◽  
Design Constraint ◽  
Treated Soil ◽  
Lime Content ◽  
Spread Footings ◽  
Annealing Algorithm

Introduction: The design of spread footings over a lime-treated soil is studied as an important topic in geotechnical and environmental engineering. With the emergence and use of algorithms, it is possible to solve optimization problems in engineering, leading, for example, to decreased amounts of materials, time, energy, and work. Objective: This research aims to optimize the CO2 emission and cost of building spread footings over a treated soil with hydrated lime using the modified simulated annealing algorithm (MSAA). Method: The parameters for shear strength (cohesion and friction angle) was calculated of a silty soil of the Guabirotuba geological formation of Curitiba (Brazil) stabilized with different lime contents (3, 5, 7 and 9%) at different curing times (30, 90, and 180 days). Then with these parameters, the geometry of the spread footings was optimized with MSAA minimizing the cost and CO2 emissions of their construction. For the design constraint of the structures the ultimate bearing capacity of the soil was used as criteria, the settlements produced by the service load, and the base safety factor Results: The results show that most of the problems converge to the same solution for costs and CO2 emissions without depending on curing time and lime content used, due to the solutions being restricted primarily by the maximum permissible settlements. Conclusions: With the increase in lime content, the cohesion of the mixtures increased for all curing times studied ant the friction angle had no major variations in relation to the amount of lime administered or to the curing time employed. Costs and carbon dioxide emissions for spread footing construction converge to the same results. In this sense, 9% lime can be avoided, and small percentages of lime (i.e. 3-5%) are appropriated to ground improvement and reduce the costs of this procedure. On the other hand, the MSAA can be designated as a robust algorithm due to having achieved almost equal results and, in some cases, better results compared with other algorithms to solve problems reported in the literature.

An Optimum Design of Crowned Cylindrical Roller Bearings Using Genetic Algorithms

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
K. Sunil Kumar ◽  
Rajiv Tiwari ◽  
P. V. V. N. Prasad
Keyword(s):  
Genetic Algorithms ◽  
Fatigue Life ◽  
Stress Concentration ◽  
Stress Concentrations ◽  
Rolling Bearings ◽  
Design Constraint ◽  
Roller Bearings ◽  
Edge Stress ◽  
Heavy Loads ◽  
Cylindrical Roller

The long fatigue life is the one of the most important criterion for the design of rolling bearings, however, due to complex and diverse internal geometries, each type of rolling bearings require a different design formulation. To increase the life of cylindrical roller bearings, the profile (or the crowning) of the roller plays an important role. A flat profile of the rolling element results in the edge stress concentrations at roller ends. A circular crowning of roller eliminates the edge stress concentration at the lower and moderate loads only; however, it develops edge stress concentrations at heavy loads. The logarithmic profile of the roller results in no edge stress concentration at the low, medium, and heavy loads; distribution of contact stresses is also nearly uniform along the length of the roller. A design methodology for the optimum design of cylindrical roller bearings with the logarithmic profile has been outlined. A nonlinear constrained optimization problem has been formulated for the design of cylindrical roller bearings with logarithmic profiles and is optimized by using real-coded genetic algorithms. The change in roller profile has not been accounted for explicitly in the standard definition of the dynamic capacity; hence, for the present case directly the Lundberg–Palmgren life equation has been chosen as an objective function. Design variables include four bearing geometrical parameters and the two logarithmic profile generating parameters are considered. In addition to these, another five design constraint constants are also included, which indirectly affect the fatigue life of cylindrical roller bearings. The five design constraint constants have been given bounds based on the parametric studies through initial optimization runs. The effective length of the roller is taken corresponding to the standard roller diameter, which has standard discrete dimensions. Constraint violation study has been performed to have an assessment of the effectiveness of each of the constraints. A convergence study has been carried out to ensure the global optimum point in the design. A sensitivity analysis of various geometric design parameters has been performed using the Monte Carlo simulation technique, in order to see changes in the fatigue life of the bearing. Illustrations show that the multiplier of the logarithmic profile deviation parameter has more effect on the fatigue life as compared with other geometric parameters.

scholarly journals A Screw Theory Approach for the Type Synthesis of Compliant Mechanisms With Flexures

2009 ◽  
Author(s):  
Hai-Jun Su ◽  
Denis V. Dorozhkin ◽  
Judy M. Vance
Keyword(s):  
Compliant Mechanisms ◽  
Screw Theory ◽  
Compliant Mechanism ◽  
Computational Techniques ◽  
Theory Approach ◽  
Type Synthesis ◽  
Precision Engineering ◽  
Pattern Design ◽  
Design Constraint ◽  
Systematic Formulation

This paper presents a screw theory based approach for the type synthesis of compliant mechanisms with flexures. We provide a systematic formulation of the constraint-based approach which has been mainly developed by precision engineering experts in designing precision machines. The two fundamental concepts in the constraint-based approach, constraint and freedom, can be represented mathematically by a wrench and a twist in screw theory. For example, an ideal wire flexure applies a translational constraint which can be described a wrench of pure force. As a result, the design rules of the constraint-based approach can be systematically formulated in the format of screws and screw systems. Two major problems in compliant mechanism design, constraint pattern analysis and constraint pattern design are discussed with examples in details. This innovative method paves the way for introducing computational techniques into the constraint-based approach for the synthesis and analysis of compliant mechanisms.

Performance comparison of electrorheological valves with two different geometric configurations: Cylinder and plate

2008 ◽  
Vol 223 (3) ◽  
pp. 573-581 ◽  
Author(s):  
Y-M Han ◽  
K-G Sung ◽  
J W Sohn ◽  
S-B Choi
Keyword(s):  
Pressure Drop ◽  
Response Time ◽  
Analytical Model ◽  
Performance Comparison ◽  
Time Varying ◽  
Control Performance ◽  
Electrode Gap ◽  
Design Constraint ◽  
Geometric Configurations ◽  
Er Fluid

This article presents a control performance comparison of electrorheological (ER) fluid-based valves between cylindrical and plate configurations. After identifying Bingham characteristics of chemical starch-based ER fluid, an analytical model of each valve is established. In order to reasonably compare valve performance, design constraint is imposed by the choosing the same electrode gap and length, and each ER valve is manufactured. Valve performances such as pressure drop and response time are then evaluated and compared through analytical model and experiment. In addition, a time-varying pressure tracking controllability of each ER valve is experimentally realized.

Synthesis of Defect Free Six Bar Linkages for Body Guidance Through up to Six Finitely Separated Positions

1994 ◽  
Author(s):  
Timothy Tylaska ◽  
Kazem Kazerounian
Keyword(s):  
Design Problem ◽  
Design Methodology ◽  
Complete Solution ◽  
Higher Order ◽  
Synthesis Problem ◽  
Design Constraint ◽  
Solution Sets ◽  
Constraint Equations ◽  
Design Considerations ◽  
Highly Nonlinear

Abstract In the synthesis of watt I six bar linkage, for finitely separated design positions, or in higher order design, constraint equations become highly nonlinear and transcendental. This paper presents a method to decouple the synthesis problem to the synthesis of two path generator 4-bar linkages. Based on this decoupled system, an explicit design methodology is developed, enabling a three, four, five or six body guidance position Watt I linkage to be designed while the designer has choice of some body pivots and ground pivots. Numerical procedures for higher number of positions are also discussed. The methodology allows the designer to obtain an entire set of solutions to a particular design problem. As a spin off from this work, a methodology is also presented to obtain complete solution sets of four bar path generators capable of passing through up to seven precision points, with a procedure that can be eventually extended to eight and nine path points. Design considerations such as branching and transmission angles are also considered.

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