Research on high precision matching optimization method and software testing analysis of regions with fuzzy details of multimedia images in cloud environment

2016 ◽  
Vol 76 (16) ◽  
pp. 17019-17035
Author(s):  
Jianxin Ge ◽  
Jiaomin Liu
Keyword(s):  
Software Testing ◽  
High Precision ◽  
Optimization Method ◽  
Cloud Environment

Synthesis of a High-Precision Missile Homing System with an Permissible Stability Margin of the Normal Acceleration Stabilization System

2021 ◽  
Vol 22 (7) ◽  
pp. 365-373
Author(s):  
Quang Thong Do
Keyword(s):  
High Precision ◽  
Parametric Optimization ◽  
Stability Margin ◽  
Optimization Method ◽  
Synthesis Process ◽  
Stabilization System ◽  
Gain Margin ◽  
The Stability ◽  
Automatic Systems ◽  
Normal Acceleration

The proportional guidance method-based missile homing systems (MHS) have been widely used the real-world environments. In these systems, in order to destroy the targets at different altitudes, a normal acceleration stabilization system (NASS) is often utilized. Therefore, the MHS are complex and the synthesis of these systems are a complex task. However, it is necessary to synthesize NASS during the synthesis of the MHS. To simplify the synthesis process, a linear model of the NASS is used. In addition, we make use of the available commands in Control System Toolbox in MATLAB. Because the Toolbox has the commands to describe the transfer function, determine the stability gain margin, and the values of the transient respond of the linear automatic systems. Thus, this article presents two methods for synthesizing the missile homing systems, including (i) a method for synthesizing the MHS while ensuring the permissible stability gain margin of the NASS, and (ii) a method for synthesizing the MHS while ensuring the permissible stability margin of the NASS by overshoot. These techniques are very easy to implement using MATLAB commands. The synthesis of the proposed MHS is carried out by the parametric optimization method. To validate the performance of the proposed techniques, we compare them withthe MHS synthesized by ensuring the stability margin of the NASS bythe oscillation index. The results show that, two our proposed methods and the existing method provide the same results in terms of high-precision. Nevertheless, the proposed methods are simple and faster than the conventional method. The article also investigates the effect of gravity, longitudinal acceleration of the rocket, andblinding of the homing head on the accuracy of the synthesized MHS. The results illustrate that they have a little effect on its accuracy.

Synthesis of High-Precision Missile Homing System Using Proportional Guidance Method

2020 ◽  
Vol 21 (4) ◽  
pp. 242-248
Author(s):  
Do Quang Thong
Keyword(s):  
High Precision ◽  
Parametric Optimization ◽  
Initial Conditions ◽  
Dynamic Parameter ◽  
Optimization Method ◽  
Line Of Sight ◽  
Initial Condition ◽  
Optimal Parameters ◽  
Ballistic Missiles ◽  
Low Visibility

Modern air targets are characterized by low visibility, high maneuverability and high survivability. In addition, for some specific targets, for instance ballistic missiles, in order to defeat them the missile need tobe guided and carried out direct hit, i.e. "hit to kill". Therefore, in this paper, we present a high-precision missile homing system (MHS) using the proportional guidance method for firing at the highly maneuverable targets. Specifically, we propose a parametric optimization method for choosing a set of optimal parameters of the missile homing system for each dynamic parameter set of the missile. In addition, the paper gives the recommendations of choosing the initial conditions for the synthesis of missile homing system. In our experience, we should choose the small initial condition for synthesizing the missile homing system. Finally, the article also investigates the influence of systematic error in determining the speed, normal acceleration of missiles and the angular velocity of the line of sight of the missile and target on the accuracy of the missile homing system. We implement the proposed missile homing system and the parametric optimization method in Matlab. The experimental results illustrate that, using proposed system and the parametric optimization method, the missile can defeat the modern air targets with low visibility, high maneuverability and high survivability. 

scholarly journals A High Precision Time Grating Displacement Sensor Based on Temporal and Spatial Modulation of Light-Field

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 921 ◽  
Author(s):  
Min Fu ◽  
Changli Li ◽  
Ge Zhu ◽  
Hailin Shi ◽  
Fan Chen
Keyword(s):  
High Precision ◽  
Light Field ◽  
Light Transmission ◽  
Low Cost ◽  
Optimization Method ◽  
Spatial Modulation ◽  
Displacement Sensor ◽  
High Precision Measurement ◽  
Object Movement ◽  
Field Modulation

A new displacement sensor with light-field modulation, named as time grating, was proposed in this study. The purpose of this study was to reduce the reliance on high-precision measurements on high-precision manufacturing. The proposed sensor uses a light source to produce an alternative light-field simultaneously for four groups of sinusoidal light transmission surfaces. Using the four orthogonally alternative light-fields as the carrier to synthesize a traveling wave signal which makes the object movement in the spatial proportion to the signal phase shift in the time, the moving displacement of the object can be measured by counting time pulses. The influence of the light-field distribution on sensor measurement error was analyzed in detail. Aimed to reduce these influences, an optimization method that used continuous cosinusoidal light transmission surfaces with spatially symmetrical distribution was proposed, and the effectiveness of this method was verified with simulations and experiments. Experimental results demonstrated that the measurement accuracy reached 0.64 μm, within the range of 500 mm, with 0.6 mm pitch. Therefore, the light-field time grating can achieve high precision measurement with a low cost and submillimeter period sensing unit.

scholarly journals Trade-off analysis for structural design of high-precision space reflector using multiobjective optimization method

2015 ◽  
Vol 2 (4) ◽  
pp. 15-00058-15-00058
Author(s):  
Ryo KODAMA ◽  
Nozomu KOGISO ◽  
Masahiro TOYODA ◽  
Hiroaki TANAKA
Keyword(s):  
Multiobjective Optimization ◽  
High Precision ◽  
Structural Design ◽  
Optimization Method ◽  
Trade Off

scholarly journals A Constraint-Aware Optimization Method for Concurrency Bug Diagnosis Service in a Distributed Cloud Environment

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Lili Bo ◽  
Shujuan Jiang
Keyword(s):  
Data Access ◽  
Optimization Method ◽  
Service Performance ◽  
Cloud Environment ◽  
Security Issue ◽  
Concurrent Software ◽  
Concurrent Program ◽  
Cloud Computation ◽  
Distributed Cloud ◽  
Concurrency Bug

The advent of cloud computation and big data applications has enabled data access concurrency to be prevalent in the distributed cloud environment. In the meantime, security issue becomes a critical problem for researchers to consider. Concurrency bug diagnosis service is to analyze concurrent software and then reason about concurrency bugs in them. However, frequent context switches in concurrent program execution traces will inevitably impact the service performance. To optimize the service performance, this paper presents a static constraint-aware method to simplify concurrent program buggy traces. First, taking the original buggy trace as the operation object, we calculate the maximal sound dependence relations based on the constraint models. Then, we iteratively check the dependent constraints and move forward current event to extend thread execution intervals. Finally, we obtain the simplified trace that is equivalent to the original buggy trace. To evaluate our approach, we conduct a set of experiments on 12 widely used Java projects. Experimental results show that our approach outperforms other state-of-the-art approaches in terms of execution time.

Sign in / Sign up

Export Citation Format

Share Document