Optimal design of pressure vessel using an improved genetic algorithm

As the idea of simulated annealing （SA） is introduced into the fitness function, an improved genetic algorithm （GA） is proposed to perform the optimal design of a pressure vessel which aims to attain the minimum weight under burst pressure constraint. The actual burst pressure is calculated using the arc-length and restart analysis in finite element analysis （FEA）. A penalty function in the fitness function is proposed to deal with the constrained problem. The effects of the population size and the number of generations in the GA on the weight and burst pressure of the vessel are explored. The optimization results using the proposed GA are also compared with those using the simple GA and the conventional Monte Carlo method.     

Assessing the counselling needs of high school students in Kenya

The Student Counselling Needs Scale (SCNS) was administered to 867 participants recruited from high schools in Kenya. The data were analyzed using exploratory factor analysis yielding five factors: human relationships, career development, self development, social values, and learning skills were assessed. The findings highlighted the importance of using assessment instruments to identify students’ counselling needs in Kenya.     

The Experience of Columbian Child Soldiers from a Resilience Perspective

There are child soldiers fighting with government forces and opposition groups in more than 30 countries worldwide. Although studies have been conducted on the impact of war-related trauma on children, very few have focused on those children who do not exhibit trauma-related symptoms after experiencing armed combat. The purpose of this study was to identify and understand some of the mechanisms and resources that resilient children draw upon to overcome the trauma of child soldiering. Six Colombian child soldiers were recruited through purposive sampling techniques to participate in a narrative study focusing on their lived experiences and their personal understanding of how they were able to overcome the effects of war trauma. Six narrative themes were identified and discussed in terms of the literature on trauma and childhood resilience and also related to counselling needs and services.     

基于遗传算法的Ad-hoc网络安全多目标优化认证机制研究

节点的安全性是Ad-hoc网络面临的重要问题,因为通过非安全节点可以窃取、篡改网络中的数据包,甚至对网络造成致命性的破坏。通常情况下,Ad-hoc网络是借助于基于密钥的认证算法来实现节点的安全性保障的,但是这些认证算法并不适用于Ad-hoc的特殊网络环境。将遗传算法应用于节点安全性认证领域,通过基于多目标优化的认证机制,取代了密钥认证机制。通过模拟实验表明,基于多目标优化的认证机制,在Ad-hoc网络环境中,性能较为优越。     

纤维素酶研究进展

对纤维素利用中的核心热点问题——纤维素酶的生态分布、酶的组成、纤维素酶活性功能区、纤维素酶的作用机理、纤维素酶的表达调控的基础研究和纤维素酶的实际应用研究的进展作了综合评述.     

Estimation of Shallow S-Wave Velocity Structure of Two Practical Sites from Microtremors Array Observation in Tangshan Area

Microtremors array observation for estimating S-wave velocity structure from phase velocities of Rayleigh and Love wave on two practical sites in Tangshan area by a China-US joint group are researched.The phase velocities of Rayleigh wave are estimated from vertical component records and those of Love wave are estimated from three-component records of microtremors array using modified spatial auto-correlation method.Haskell matrix method is used in calculating Rayleigh and Love wave phase velocities,and the shallow S-wave velocity structure of two practical sites are estimated by means of a hybrid approach of Genetic Algorithm and Simplex.The results are compared with the PS logging data of the two sites,showing it is feasible to estimate the shallow S-wave velocity structure of practical site from the observation of microtremor array.     

Genetic polymorphism analyses of a novel panel of 19 X-STR loci in the Chinese Uygur ethnic minority

The population genetic data and forensic parameters of 19 X-chromosome short tandem repeat (X-STR) loci in Chinese Uygur ethnic minority are presented. These loci were detected in a sample of 233 (94 males and 139 females) unrelated healthy individuals. We observed 238 alleles at the 19 X-STR loci, with the corresponding gene frequencies spanning the range from 0.0021 to 0.5644. After Bonferroni correction (P>0.0026), there were no significant deviations from Hardy-Weinberg equilibrium. The cumulative power of discrimination in females and males, and the probability of exclusion of the 19 X-STR loci were 0.999 999 999 999 999 999 998 091, 0.999 999 999 999 966, and 0.999 999 986 35, respectively. The cumulative mean exclusion chance was 0.999 999 992 849 in deficiency cases, 0.999 999 999 999 628 in normal trios, and 0.999 999 998 722 in duo cases. The high value of the forensic parameters mentioned above revealed that the novel panel of 19 loci had important values for forensic applications in the Uygur group.     

Multiobjective optimization and multivariable control of the beer fermentation process with the use of evolutionary algorithms

INTRODUCTIONThefermentationprocesshasgreatscientificandpracticalimportance.Forseveralreasons,qua-litycontrol,forexample,itisimportanttoincludeallkindsoftechnologicaladvancesintheindustrialprocesses.Thisisthemainaimofourresearch,whichisverycomplexduetothenon-linearityofthestudiedphenomena.Themathematicalmodelsfoundinliteratureincludeonlylaboratoyconditions.Amathematicalmodelhasbeendevelopedforthebeerfermentationprocessbecauseoftheadvantagesthatitprovides.Itallowssimulatingwhatcanhappenwhe…     

Algorithm for 2D irregular-shaped nesting problem based on the NFP algorithm and lowest-gravity-center princlple

The nesting problem involves arranging pieces on a plate to maximize use of material. A new scheme for 2D irregular-shaped nesting problem is proposed. The new scheme is based on the NFP （No Fit Polygon） algorithm and a new placement principle for pieces. The novel placement principle is to place a piece to the position with lowest gravity center based on NFP. In addition, genetic algorithm （GA） is adopted to find an efficient nesting sequence. The proposed scheme can deal with pieces with arbitrary rotation and containing region with holes, and achieves competitive results in experiment on benchmark datasets.     

Application of stochastic method to optimum design of energy-efficient induction motors with a target of LCC

INTRODUCTIONMostcountrieshaveimplementednewpoli ciesontheenergysavingandenvironmentpro tection.AmericanPresidentBushsigned“TheComprehensiveNationalEnergyPolicyAct”in1992statingthatnogeneral purpose ,three phaseinductionmotorswillbeallowedintoUnit edStat…