A hybrid directional step method for minimum performance target point search

2018 ◽  
Vol 62 ◽  
pp. 103-118 ◽  
Author(s):  
Weiqi Du ◽  
Yuanxin Luo ◽  
Yongqin Wang
Keyword(s):  
Target Point ◽  
Step Method ◽  
Point Search ◽  
Minimum Performance Target Point ◽  
Minimum Performance ◽  
Performance Target

scholarly journals A new method on motion planning for mobile robots using jump point search and Bezier curves

2021 ◽  
Vol 18 (4) ◽  
pp. 172988142110192
Author(s):  
Ben Zhang ◽  
Denglin Zhu
Keyword(s):  
Motion Planning ◽  
Initial Point ◽  
Target Point ◽  
Jump Point ◽  
Bezier Curves ◽  
Bézier Curves ◽  
Front End ◽  
Planning Algorithm ◽  
Point Search ◽  
Path Planning Algorithm

Innovative applications in rapidly evolving domains such as robotic navigation and autonomous (driverless) vehicles rely on motion planning systems that meet the shortest path and obstacle avoidance requirements. This article proposes a novel path planning algorithm based on jump point search and Bezier curves. The proposed algorithm consists of two main steps. In the front end, the improved heuristic function based on distance and direction is used to reduce the cost, and the redundant turning points are trimmed. In the back end, a novel trajectory generation method based on Bezier curves and a straight line is proposed. Our experimental results indicate that the proposed algorithm provides a complete motion planning solution from the front end to the back end, which can realize an optimal trajectory from the initial point to the target point used for robot navigation.

Reliability-Based Design Optimization Using Step Length Adjustment Algorithm and Sequential Optimization and Reliability Assessment Method

2019 ◽  
Vol 16 (07) ◽  
pp. 1850109 ◽  
Author(s):  
Ping Yi ◽  
Dongchi Xie ◽  
Zuo Zhu
Keyword(s):  
Design Optimization ◽  
Reliability Assessment ◽  
Step Length ◽  
Assessment Method ◽  
Sequential Optimization ◽  
Target Point ◽  
Reliability Based Design Optimization ◽  
Reliability Based Design ◽  
Inverse Reliability Analysis ◽  
Minimum Performance Target Point

A step length adjustment (SLA) iterative algorithm was proposed for locating the minimum performance target point (MPTP) in the inverse reliability analysis. This paper elaborates SLA and two deliberately designed numerical examples are used to compare SLA with other algorithms appearing in recent literatures for locating MPTP. The results show that SLA is much more robust and efficient. Then SLA and sequential optimization and reliability assessment (SORA) are combined to solve reliability-based design optimization (RBDO) problems. In the reliability assessment of SORA, with the design obtained from the previous cycle, SLA is used to locate MPTP. Then in the deterministic optimization, the boundaries of violated constraints are shifted to the feasible direction according to the MPTP obtained in the reliability assessment. Several examples frequently cited in similar studies are used to compare SORA-SLA with other RBDO algorithms. The results indicate the effectiveness and robustness of SORA-SLA.

Development of Target Point Search Methods for Course Following Systems: Treating Vehicle Control

2000 ◽  
Author(s):  
Frank R. Schaefer ◽  
Marc Ramsey ◽  
Imtiaz Haque ◽  
Jürgen Schuller
Keyword(s):  
Driver Model ◽  
Target Point ◽  
Point Selection ◽  
Lateral Deviation ◽  
Search Methods ◽  
Dynamic Planning ◽  
Point Search ◽  
Clear Guideline ◽  
Selection For ◽  
Spatial Objectives

Abstract This paper addresses target point search methods for course following systems. A central concept in the development of the control algorithms for such systems is that of target point selection. For a given driving situation, target points constitute spatial objectives that the control algorithm strives to realize. The results presented in this paper are based on experiments made with a recently developed new driver model [Schaefer and Schuller, 1999]. The model establishes control in two steps: geometric dynamic planning and plan-to-action mapping. The separation into these two units allows one to investigate the process of target point search independently. Target point search is conducted for the guidance of a vehicle’s c.g., i.e. a system thats trajectory can be assumed to have ‘differentiable’ curvature profile. The concepts introduced here, however, may easily be generalized to any system whose state transition (i.e. trajectory) may be described locally by instantaneous circles and that has to follow an abstract nominal path in the state space. A so called situational driving motivation ‘SDM’ is formulated that defines a clear guideline for geometric dynamic planning based on an time isolated situation. A number of different search methods including Preview Point Search, End of Sight Search, Deviation Dependent Preview Point, and a so-called Nestle Point Search, are investigated. The results are evaluated on the basis of the vehicle’s ability to go around a course with a minimum lateral deviation from the nominal course. The results show that the Nestle Curve Search method provides the best performance.

A Quantile-Based SORA Method Using Maximum Entropy Method With Fractional Moments

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Wanxin He ◽  
Hua Yang ◽  
Gang Zhao ◽  
Yan Zeng ◽  
Gang Li
Keyword(s):  
Maximum Entropy ◽  
Maximum Entropy Method ◽  
Assessment Method ◽  
Entropy Method ◽  
Sequential Optimization ◽  
Target Point ◽  
Reliability Based Design ◽  
Reliability Method ◽  
Fractional Moments ◽  
Minimum Performance Target Point

Abstract Reliability-based design optimization (RBDO) is receiving more attention from researchers because it can help to minimize cost reasonably in practical engineering. A large number of methods have been proposed to solve RBDO problems, most of which are based on the theory of the first-order reliability method (FORM). Therefore, the deficiencies of the FORM limit applications of general RBDO methods such as the dependency on the minimum performance target point (MPTP). In this study, we apply the fractional moment-based maximum entropy method to the RBDO problems for the first time and propose a novel RBDO method using the quantile-based sequential optimization and reliability assessment method. Because the proposed method is MPTP free, the shortcomings of FORM-based RBDO methods can be overcome. To demonstrate the performance of the proposed method, we test five numerical examples and one engineering example by the proposed method and three popular RBDO methods. The results show that the proposed method can balance the accuracy and the efficiency compared with other methods.

Purification of Urokinase from Complex Mixtures Using Immobilized Monoclonal Antibody Against Urokinase Light Chain

1983 ◽  
Vol 49 (01) ◽  
pp. 024-027 ◽  
Author(s):  
David Vetterlein ◽  
Gary J Calton
Keyword(s):  
Monoclonal Antibody ◽  
Light Chain ◽  
Culture Media ◽  
Biological Fluids ◽  
Single Step ◽  
High Yield ◽  
Step Method ◽  
Commercial Preparation ◽  
E Coli ◽  
Tissue Culture Media

SummaryThe preparation of a monoclonal antibody (MAB) against high molecular weight (HMW) urokinase light chain (20,000 Mr) is described. This MAB was immobilized and the resulting immunosorbent was used to isolate urokinase starting with an impure commercial preparation, fresh urine, spent tissue culture media, or E. coli broth without preliminary dialysis or concentration steps. Monospecific antibodies appear to provide a rapid single step method of purifying urokinase, in high yield, from a variety of biological fluids.

NUMERICAL MODEL TO SIMULATE THE EROSION ON THE SLOPE DUE TO OVERTOPPING

2010 ◽  
Vol 13 (3) ◽  
pp. 78-87
Author(s):  
Hoai Cong Huynh
Keyword(s):  
Numerical Model ◽  
Flow Model ◽  
Bed Load ◽  
Experiment Data ◽  
Step Method ◽  
Morphological Model ◽  
Load Transport ◽  
Bed Load Transport ◽  
The Finite Difference Method ◽  
Good Agreement

The numerical model is developed consisting of a 1D flow model and the morphological model to simulate the erosion due to the water overtopping. The step method is applied to solve the water surface on the slope and the finite difference method of the modified Lax Scheme is applied for bed change equation. The Meyer-Peter and Muller formulae is used to determine the bed load transport rate. The model is calibrated and verified based on the data in experiment. It is found that the computed results and experiment data are good agreement.

The Use of Cost-Benefit Analysis for Evaluating Efficiency of Public Investment Projects (The Case of Sochi-2014 Winter Olympic Games)

2011 ◽  
pp. 57-78
Author(s):  
I. Pilipenko
Keyword(s):  
Net Present Value ◽  
Olympic Games ◽  
Cost Benefit Analysis ◽  
Public Investment ◽  
Cost Benefit ◽  
Investment Efficiency ◽  
Benefit Analysis ◽  
Step Method ◽  
Investment Projects ◽  
The Usa

The paper analyzes shortcomings of economic impact studies based mainly on input- output models that are often employed in Russia as well as abroad. Using studies about sport events in the USA and Olympic Games that took place during the last 30 years we reveal advantages of the cost-benefit analysis approach in obtaining unbiased assessments of public investments efficiency; the step-by-step method of cost-benefit analysis is presented in the paper as well. We employ the project of Sochi-2014 Winter Olympic and Paralympic Games in Russia to evaluate its efficiency using cost-benefit analysis for five accounts (areas of impact), namely government, households, environment, economic development, and social development, and calculate the net present value of the project taking into account its possible alternatives. In conclusion we suggest several policy directions that would enhance public investment efficiency within the Sochi-2014 Olympics.

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