Orthogonal Design Method for Optimizing Roughly Designed Antenna

In the paper, the analysis of wave scattering on a system of two soundproof spheres was carried out using the orthogonal central compositional design method. The main objectives of the work are to determine the main parameters, the change of which significantly affects on the whole system; to determine the variable parameter values of the system, at which the loss functions (the total scattering cross section and the normalized pressure at a fixed point) take the minimum and maximum values, and to study the system at optimal parameter values. The orthogonal compositional design method is implemented for a three-factor computational experiment, where three main parameters of the system were selected as factors: the wave radius, the ratio of the sphere radii, and the distance between the sphere centers. For the obtained regression equation, the significance of the coefficients was checked using Student’s t-test and the adequacy of the model using Fisher’s F-test. It was found that in the case of a spherical wave from a monopole radiation source, the nonlinear influence of the factors is more pronounced than in the case of a plane wave; normal pressure calculated at a fixed point is insensitive to changes in parameters in the case of a plane wave, as well as in the case of a monopole radiation source for small values of the sphere surface complex conductivity; the total scattering cross section is highly sensitive in the case of a system with ideally rigid spheres; the highest and lowest values of the loss functions are achieved at the boundary of the three-dimensional parametric region of factors changes. Pressure distribution diagrams were constructed, which made it possible to determine the zones of high or low pressure for the found optimal values of the factors.

The last decade has witnessed a great interest on the application of evolutionary algorithms, such as genetic algorithm (GA), particle swarm optimization (PSO) and gene expression programming (GEP), for optimization problems. This paper presents a hybrid algorithm by combining the GEP algorithm and the orthogonal design method. A multiple-parent crossover operator is introduced for the chromosome reproduction using the orthogonal design method. In addition, an evolutionary stable strategy is also employed to maintain the population diversity during the evolution. The efficiency of the proposed algorithm is evaluated using three benchmark problems. The results demonstrate that the proposed hybrid algorithm has a better generalization ability compared to conventional algorithms.

The flow field inside cyclone separator is a kind of complex three-dimensional rotation turbulent flow with two-phase separation phenomenon. In order to optimize the structure and shorten the cycle of research and development, it is very essential to find the appropriate calculation method for the flow field inside cyclone separator. In this article, the internal flow field of tangential inlet cyclone separator was simulated and calculated by adopting different calculation model and different numerical simulation scheme by orthogonal design method. And the result was compared with that of existing experiment to find a reasonable method for the simulation of the flow field inside the cyclone. On the basis of standard k-ε model, the numerical simulation scheme was formulated by the orthogonal test method, through the comparison of results, the best combinations are gained; This research result has certain reference value for cyclone separator design and performance optimization.

Development of a dual phase steel using orthogonal design method

Design and multi-objective optimization of hairpin motor cooling system based on orthogonal design method and composite algorithm

In order to improve the performance of a four stroke marine engine, a new marine diesel engine has been developed based on the baseline engine. The crank speed of the new developed engine is higher than the baseline engine and the stroke is shortened. However, the compression ratio is unchanged. The shortened stroke of the new developed engine enhances the tendency of spray-wall impingement and combustion deteriorated which results from the reduction of the squish height. To solve this problem, four factors in combustion system: nozzle protrusion height, the upper nozzle angle, the lower nozzle angle and the injection timing, are optimized based on orthogonal design method. Under the restriction of in-cylinder pressure 20MPa, -9 °CA is the optimal injection timing. When the nozzle protrusion height is 7mm, the upper nozzle and lower nozzle angle are 170° and 160° respectively, the spray and flame relatively evenly distribute in the combustion chamber, further strengthens the utilization of fresh air and then enhance the output of engine.

A high specific speed centrifugal pump is used in the situation of large flow and low head. Centrifugal pump parameters need to be optimized in order to raise its head and efficiency under off-design conditions. In this study, the orthogonal experiment design method is adopted to optimize the performance of centrifugal pump basing on three parameters, namely, blade outlet width b2, blade outlet angle β2 and blade wrap angle φ. First, the three-dimensional model of the centrifugal pump is established by CFturbo and SolidWorks. Then nine different schemes are designed by using orthogonal table, and numerical simulation is carried out in CFX15.0. The final optimized combination of parameters is b2 = 24 mm, β2 = 24°, φ = 112°. Under the design condition, the head and efficiency of the optimized centrifugal pump are appropriately improved, the increments of which are 0.74 m and 0.48%, respectively. However, the efficiency considerably increases at high flow rates, with an increase of 6.9% at 1.5 Qd. The anti-cavitation performance of the optimized centrifugal pump is also better than the original pump. The results in this paper can provide references for parameter selection (b2, β2, φ) in the centrifugal pump design.

Use of an orthogonal design method to study two-stage chemical carcinogenesis in BALB/3T3 cells.

On-line conversion and determination of artemisinin and its kinetic parameters using orthogonal design by coupling of flow injection with capillary electrophoresis

Purpose: Preparation of gel-formed Dachuanxiong prescription. Method: In this experiment, liquid chromatograph is used to measure the content of gastrodin in gastrodia elata and orthogonal design method is adopted to optimize the technological conditions for extracting gastrodin. Comprehensive evaluation is conducted based on examination factors including dry powder, glycerol, hydroxypropyl methylcellulose and borneol as well as indexes including viscosity, appearance and spreadability, through which prescription can be screened and optimized, and gel-formed Dachuanxiong prescription can thus be prepared. Result: Content of gastrodin in gastrodia elata as raw material is 0.53%, and excipient should be gel made from 1 g of ethanol, 1.5 g of hydroxypropyl methylcellulose, 10 g of glycerol, 0.01 g of borneol and 100 g of water. Conclusion: This technology for preparation of gel is stable and simple, which can increase the content of ferulic acid obviously. Preparation of pure traditional Chinese medicine is delivered through nasal mucosa to relieve headache and mainly used to treat headache.[1]Chuanxiong Prescription was established by Liu Wansu, a well-known doctor living in the Jin and Yuan Dynasty. In this prescription, ligusticum wallichii can invigorate the circulation of blood and promote the circulation of qi, and gastrodia elata can relieve dizziness and pain. Combination of them can realize a good effect for the treatment of migraine caused by blood stasis and fire. This prescription is simple and effective. Based on physical and chemical properties of various medical materials, active ingredients in them can be extracted with the method of alcohol extraction. [2-4]According to result of document retrieval and patent search, volume fraction, number of times of extraction and time of extraction should be used as conditions of examination. [1]However, it can be verified through in-depth research on physical and chemical properties and pharmacological actions of medical materials in the prescription as well as repetitive tests that number of times of extraction have an obvious influence on extraction rate. Based on the above content, factors of examination in the experiment are determined and examination through orthogonal experiment is thus carried out, through which technological conditions that can realize a high rate of extraction of gastrodin (index component) is screened out. This experiment selects the optimal technology for extracting gel which can relieve headache and be delivered through nasal mucosa, in which orthogonal test method is applied, and content of gastrodin is viewed as an index. Ethanol should be used in the optimal extraction technology. The optimal technology is stable and practicable, which can obviously increase the content of ferulic acid.

An indoor experimental model of flow in crossed smooth karst pipe and fissure is set up for testing hydraulic characteristic. The model and its measuring system, including crossed karst pipe and fissure and water circulation System etc., are introduced in detail. By use of the orthogonal design method, about 48 test data of hydraulic characteristic of crossed karst pipe and fissure are obtained under different cross angle and water head etc., and the test results are analyzed briefly by use of the orthogonal statistical analysis method. The influence of fissure width, karst dimension and inlet water head on pipe flow and water head loss are analyzed.

Research into ant colony algorithms for solving continuous optimization problems forms one of the most significant and promising areas in swarm computation. Although traditional ant algorithms are designed for combinatorial optimization, they have shown great potential in solving a wide range of optimization problems, including continuous optimization. Aimed at solving continuous problems effectively, this paper develops a novel ant algorithm termed “continuous orthogonal ant colony” (COAC), whose pheromone deposit mechanisms would enable ants to search for solutions collaboratively and effectively. By using the orthogonal design method, ants in the feasible domain can explore their chosen regions rapidly and efficiently. By implementing an “adaptive regional radius” method, the proposed algorithm can reduce the probability of being trapped in local optima and therefore enhance the global search capability and accuracy. An elitist strategy is also employed to reserve the most valuable points. The performance of the COAC is compared with two other ant algorithms for continuous optimization — API and CACO by testing seventeen functions in the continuous domain. The results demonstrate that the proposed COAC algorithm outperforms the others.

By using the expressions of the field parameters and with the aid of the Orthogonal Design Method, we optimized the design of the saddle deflection yoke with a ferromagnetic shield. The results obtained agree with the practical model. It is pointed out that the end ear and the distribution of the field parameter B0(z) have important effects on the deflection aberrations. An example is given that compares the electron optical properties of the deflection coils with the cosine distribution and finite length with that of a distributed winding.

Objective: To select and optimize the conditions of urine cobalt determination by graphite furnace atomic absorption spectroscopy and establish a method for urine cobalt determination. Methods: In April 2020, the matrix modifier and spectrum wavelength were selected by mathematical statistics method, the heating procedure of graphite furnace was optimized, the variance of orthogonal test results was analyzed, and the working curve was quantified by external standard method. Results: The results showed that the diammonium hydrogen phosphate was a matrix modifier with a wavelength of 240.7 nm, and the optimized graphite furnace heating procedure showed a good linear relationship at 5-80 μg/L. The correlation coefficient was 0.9991. The detection limit was 0.9 μg/L, the lowest detection concentration was 1.8 μg/L. The recovery was 94.0%-101.4%, and the precision was 2.6%-5.8%. Conclusion: The orthogonal design method can efficiently and scientifically optimize the optimal combination of the various factor levels of graphite furnace atomic absorption spectrometry. The determination method established based on this has high precision and good accuracy, and can be applied to the determination of cobalt in urine.

Preparation and dynamic mechanical properties of fiber-reinforced high-strength all-coral-sand seawater concrete