A Comparative Study of Genetic Algorithm Parameters for the Inverse Problem-based Fault Diagnosis of Liquid Rocket Propulsion Systems

Fault diagnosis of liquid rocket propulsion systems （LRPSs） is a very important issue in space launch activities particularly when manned space missions are accompanied, since the safety and reliability can be significantly enhanced by exploiting an efficient fault diagnosis system. Currently, inverse problem-based diagnosis has attracted a great deal of research attention in fault diagnosis domain. This methodology provides a new strategy to model-based fault diagnosis for monitoring the health of propulsion systems. To solve the inverse problems arising from the fault diagnosis of LRPSs, GAs have been adopted in recent years as the first and effective choice of available numerical optimization tools. However, the GA has many control parameters to be chosen in advance and there still lack sound theoretical tools to analyze the effects of these parameters on diagnostic performance analytically. In this paper a comparative study of the influence of GA parameters on diagnostic results is conducted by performing a series of numerical experiments. The objective of this study is to investigate the contribution of individual algorithm parameter to final diagnostic result and provide reasonable estimates for choosing GA parameters in the inverse problem-based fault diagnosis of LRPSs. Some constructive remarks are made in conclusion and will be helpful for the implementation of GA to the fault diagnosis practice of LRPSs in the future.

A Comparative Study on the Tense-Aspect of Auxiliary in English and Chinese

The aim of the paper is to give a general comparison about the structural composition of the AUX in English and Chinese mainly from the perspective of tense-aspect.Based on the basic construction of English AUX system,which includes such elements as Tense,Modal,Perfect aspect,Progressive aspect and Passive,the paper focuses on comparing the syntactic characteristics of tense element in the two languages.The final part of the paper briefly summarized predicted learning problems that Chinese learners of English as well as English learners of Chinese would have in learning English and Chinese respectively.

A Memetic Algorithm With Competition for the Capacitated Green Vehicle Routing Problem

In this paper, a memetic algorithm with competition(MAC) is proposed to solve the capacitated green vehicle routing problem(CGVRP). Firstly, the permutation array called traveling salesman problem(TSP) route is used to encode the solution, and an effective decoding method to construct the CGVRP route is presented accordingly. Secondly, the k-nearest neighbor(k NN) based initialization is presented to take use of the location information of the customers. Thirdly, according to the characteristics of the CGVRP, the search operators in the variable neighborhood search(VNS) framework and the simulated annealing(SA) strategy are executed on the TSP route for all solutions. Moreover, the customer adjustment operator and the alternative fuel station(AFS) adjustment operator on the CGVRP route are executed for the elite solutions after competition. In addition, the crossover operator is employed to share information among different solutions. The effect of parameter setting is investigated using the Taguchi method of design-ofexperiment to suggest suitable values. Via numerical tests, it demonstrates the effectiveness of both the competitive search and the decoding method. Moreover, extensive comparative results show that the proposed algorithm is more effective and efficient than the existing methods in solving the CGVRP.

A Critical Review of “A Comparative study of the effects of input-based and production-based instruction on vocabulary acquisition by young EFL learners”

A critical review of an article titled"A Comparative study of the effects of input-based and production-based instruction on vocabulary acquisition by young EFL learners"will be conducted. On the one hand, the reviewed study has reached its significance in the achievement of the comparative effects of input-based and production-based tasks on vocabulary acquisition. On the other hand, some problems can be found in the study, from research method to its discussion. The present paper is devoted to analyzing main aspects of the article one by one and providing corresponding suggestions.

Spatial Segregation Limit of a Quasilinear Competition-Diffusion System

The aim of this paper is to investigate a Volterra-Lotka competition model of quasilinear parabolic equations with large interaction. Some existence, uniqueness and convergence results for the system are given. Also investigated is its spatial segregation limit when the interspecific competition rates become large. We show that the limit problem is similar to a free boundary problem.

Spectroscopic and macroscopic studies of the adsorption of arsenate and phosphate on polynuclear aluminum organomineral precipitates

Aluminum organic coprecipitates play important roles in the transport of oxyanions in soil environment.A new polynuclear aluminum organomineral precipitate(Al13-oxalate precipitate) was prepared to investigate the adsorption behavior of arsenate and phosphate on noncrystalline aluminum precipitates.Important thermodynamic parameters for adsorption reaction were evaluated using macroscopic adsorption data and equations.The result showed that,the adsorption reaction basically is a diffusion process.FTIR spectroscopic studies have provided evidence for the formation of two different types of complexes in substrate,protonated bidentate and deprotonated bidentate complexes at pH 4 and pH≥6,respectively.The classic competitive adsorption and XPS studies both indicated that phosphate has stronger chemical interaction with substrate than arsenate.The findings of XPS studies revealed that the precipitate substrate can act as Lewis acid when adsorbing oxyanions.

Competitive analysis of price online inventory problem with cost function

In this paper,a new price is given to the online decision maker at the beginning of each day.The trader must decide how many items to purchase according to the current price.We present three variants and an online algorithm based on cost function.The competitive ratio of the online algorithm is given for each variant,which is a performance measure of an online algorithm.More importantly,we show that the online algorithm is optimal.

Competition assignment problem algorithm based on Hungarian method

Traditional Hungarian method can only solve standard assignment problems, while can not solve competition assignment problems. This article emphatically discussed the difference between standard assignment problems and competition assignment problems. The kinds of competition assignment problem algorithms based on Hungarian method and the solutions of them were studied.

Competitive analysis of online inventory problem with interrelated prices

This paper investigates the online inventory problem with interrelated prices in which a decision of when and how much to replenish must be made in an online fashion even without concrete knowledge of future prices. Four new online models with different price corre- lations are proposed in this paper, which are the linear-decrease model, the log-decrease model, the logarithmic model and the exponential model. For the first two models, the online algo- rithms are developed, and as the performance measure of online algorithm, the upper and lower bounds of competitive ratios of the algorithms are derived respectively. For the exponential and logarithmic models, the online algorithms are proposed by the solution of linear programming and the corresponding competitive ratios are analyzed, respectively. Additionally, the algorithm designed for the exponential model is optimal, and the algorithm for the logarithmic model is optimal only under some certain conditions. Moreover, some numerical examples illustrate that the algorithms based on the dprice-conservative strategy are more suitable when the purchase price fluctuates relatively flat.

The contribution of resources and capabilities to the competitiveness： The case of Port of Sines

The main objective of this paper is to analyse the competitiveness of the main maritime Port sited in Portugal - Port of Sines. This paper is developed under the resource-based view approach. A literature review about the resource-based view is presented with a special highlight on the contribution of organisation owns＇ resources to the competitiveness. With this study we intend to emphasize the applicability of a management theory to a different type of organisation which only recently starts to be preoccupied with its competitiveness. A case study methodology is used in order to collect all information needed about its main resources and capabilities of Port and also its competitiveness. The resources analysed in this paper are： The infrastructures, the accessibilities, the Port operations and also the information systems used on it. Also, a set of performance data is analysed as the main indicators of competitiveness. After that, a conceptual model is presented in order to systematise the main resources and capabilities under which the competitiveness of the Port of Sines is built on.

STUDIES ON THE COMPETITION FOR CADMIUM ION BETWEEN CHELATING AGENTS AND BOVINE SERUM ALBUMIN

Eleven chelating agents were studied for their capabilities to mobilize the cadmium bound tp bovine serum albumin(BSA).The parameter F,which is defined as the ratio between the percentages of cadmium bound to BSA in the presence and absence of chelating agents,can be used as the criterion to evaluate the mobilizing capability of chelating agent.The F values determined experimentally lead to a mobilizing capability order:DTPA>EDTA>EGTA>NTA>TR1EN>PEN>CYS>HIS>SAThe polyaminopolycarboxylate type chelators mobilize cadmium effectively.A linear relationship was found between 1gF and lg k'CdL (conditional stability constant of the cadmium chelate).

A Case Study on Primary Problem Student in Yemen

Nowadays,problem student is a common phenomenon exiting in primary and secondary school,Yemen.However,current unknown is why problem students appear and how to make an effective intervention way for reducing the problem behaviors.Although there have been many researches about problem student's problem behaviors researches on causes,developmental mechanism and educational strategies of problem students mainly stay on the theoretical research stage.This study aimed to investigate main reason for the formation of problem students and then make an effective intervention way and examine the invention effect.Firstly,combining existing research literature and teaching experience,this study sums up that problem behavior of problem students is mainly learning problem,interpersonal problem and willpower problem.Secondly,this study selected ten"problem students"of primary school as the participants.They are simply classified into three categories in accordance with the severity of the problem behaviors of problem students.I summarized various causes and affecting factors of problem behaviors through observing their performances and behaviors,and conduct in-depth interviews and explorations throughout the whole research process.Thirdly,on the basis of kind and severity of problems,various flexibly methods were used for the intervention study of problem behaviors.After that,I conducted interviews with the study cases,parents and teachers once again and made tracked records for the intervention effect.The intervention achieves marked improvement.For example,most students greatly improve their behaviors in class.Finally,I reflect the research process itself,considering that the case study is necessary method for the issue of"problem students".The use of qualitative research method is more conducive to enter the inner world of the studying cases,and better understand their true conditions as well.And on this basis,it is easier to find a breakthrough in the problem to improve the"problem students"and make a closer link between theoretical research and practical application.

Complex variable solution for boundary value problem with X-shaped cavity in plane elasticity and its application*

A new type of displacement pile, the X-section cast-in-place concrete （XCC） pile, has recently been developed in China. Extensive field tests and laboratory experi- ments are undertaken to evaluate its performance and quantify the non-uniform deforma- tion effect （NUDE） of the X-shaped cross section during installation. This paper develops a simplified theoretical model that attempts to capture the NUDE. Based on the theory of complex variable plane elasticity, closed-form solutions of the stress and displacement for the X-shaped cavity boundary value problem are given. Subsequently, the analytical solution is used to evaluate the NUDE, the concrete filling index （CFI）, and the perimeter reduction coefficient of the XCC pile cross section. The computed results are compared with field test results, showing reasonable agreement. The present simplified theoretical model reveals the deformation mechanism of the X-shaped cavity and facilitates applica- tion of the newly developed XCC pile technique in geotechnical engineering.

Competition effects in an afrotemperate forest

Background： Information about competition responses is mainly available for monospecific stands or mixed stands with a small number of species. Studies on complex multi-species and highly structured forest ecosystems are scarce. Accordingly, the objective of this study was to quantify competition effects and analyse competition responses in a species-diverse afrotemperate forest in South Africa, based on an observational study with mapped tree positions and long-term diameter increment records. Methods： The sensitivity to competition was analysed for individual species and involved the calculation of the slope of the linear relation between the value of a competition index （CI） and diameter growth as a measure of sensitivity. In a next step different competition indices were combined and tree diameters were grouped in three classes as surrogates for canopy status and ontogenetic stage. Results： Five competition indices were found to be effective in showing sensitivity to competition for a number of canopy and sub-canopy species. Significant linear regressions were fitted for 18 of a total of 25 species. Species reactions varied significantly in their sensitivity to the different CIs. The indices were classified as belonging to two groups, those that responded more to local crowding and those that are more sensitive to overtopping, which revealed species-specific sensitivities to both factors. The analysis based on diameter classes revealed that species clearly changed their sensitivity to crowding or overtopping depending on diameter. Canopy and sub-canopy species showed distinct differences in their reactions. Conclusions： The application of multiple CIs brought novel insights relating to the dynamics of afrotemperate forests. The response patterns to different competition indices that focus on crowding and overtopping are varied and tree diameter dependent, indicating that oversimplified assumptions are not warranted in the interpretation of Cl- growth relations.

Landscape Economics: Connotations, Basic Problems and Research Methods

This paper analyzed necessity and laws of natural and cultural resource consumption and creation activities as a branch of economics or research direction, proposed such basic frameworks of landscape economics such as connotations, basic problems and research methods on the basis of sorting out literature. Landscape economics is a social science focusing on the public preferences for natural and humanistic landscapes, and the preference evolution laws, economic laws of landscape resource consumption and creation activities. The basic problems include evaluation of landscape resource value, optimal utilization of landscape resources, landscape resource development and protection policies, formation and creation of diversified landscape structure. The research methods include investigation of consumers' willingness, experiment and behavioral economics, logical reasoning, and case study.

Determination of Causal Effect in Observational Studies： Analysis of Correlated Data with Binary End-Points

Identifying the causal impact of＇ some intervention challenging when one is faced with correlated binary end-points in observational studies is a challenging task, and it is even more The statistical literature on analyzing such data is well documented. Dependence between observations from the same study subject in correlated data renders invalid the usual chi-square tests of independence and inflates the variance ofparameter estimates. Disaggregated approaches such as hierarchical linear models which are able to adjust for individual level covariate：s are favoured in the analysis of such data, thereby gaining power over aggregated and individual-level analyses. In this article the authors, therefore, address the issue of analyzing correlated data with dichotomous end-points by using hierarchical logistic regression, a generalization of the standard logistic regression model for independent outcomes.

On Teaching Consonants for Freshmen of English Majors

When study English phonetics,Chinese learners will meet many difficulties,which need teachers to deal with.This paper is to discuss about how to teach consonants.

A Bi-Objective Green Vehicle Routing Problem: A New Hybrid Optimization Algorithm Applied to a Newspaper Distribution

The purpose of this work is to present a methodology to provide a solution to a Bi-objective Green Vehicle Routing Problem (BGVRP). The methodology, illustrated using a case study (newspaper distribution problem) and literature Instances, was divided into three stages: Stage 1, data treatment;Stage 2, “metaheuristic approaches” (hybrid or non-hybrid), used comparatively, more specifically: NSGA-II (Non-dominated Sorting Genetic Algorithm II), MOPSO (Multi-Objective Particle Swarm Optimization), which were compared with the new approaches proposed by the authors, CWNSGA-II (Clarke and Wright’s Savings with the Non-dominated Sorting Genetic Algorithm II) and CWTSNSGA-II (Clarke and Wright’s Savings, Tabu Search and Non-dominated Sorting Genetic Algorithm II);Stage 3, analysis of the results, with a comparison of the algorithms. An optimization of 19.9% was achieved for Objective Function 1 (OF1;minimization of CO2 emissions) and consequently the same percentage for the minimization of total distance, and 87.5% for Objective Function 2 (OF2;minimization of the difference in demand). Metaheuristic approaches hybrid achieved superior results for case study and instances. In this way, the procedure presented here can bring benefits to society as it considers environmental issues and also balancing work between the routes, ensuring savings and satisfaction for the users.