Current Issue : July - September Volume : 2012 Issue Number : 3 Articles : 5 Articles
A filter algorithm with inexact line search is proposed for solving nonlinear programming problems.\r\nThe filter is constructed by employing the normof the gradient of the Lagrangian function to\r\nthe infeasibility measure. Transition to superlinear local convergence is showed for the proposed\r\nfilter algorithm without second-order correction. Under mild conditions, the global convergence\r\ncan also be derived. Numerical experiments show the efficiency of the algorithm....
The understanding of equivalent expressions is a necessary aspect in students’ number sense towards their learning Mathematics, hence the assessment of students’ proficiency in it. This paper reports the findings from a study of equivalent expressions in number sense proficiency of Senior Secondary School students in Bwari Area Council of the Federal Capital Territory (FCT), Abuja, Nigeria. A total of 300 students, from Senior Secondary School students in Bwari Area Council of Federal Capital Territory (FCT), Abuja, Nigeria participated in this study. A majority (63%) of these students obtained C and D grades in their respective end of term school examinations. The design for this study was quantitative in nature where the data on students’ number concept sense of numbers was collected using number concept in Number Sense Test adapted from McIntosh et al, (1997).The results from this study indicate that students obtained a percentage of success rates ranging from 47.63% to 61.13% across the levels. There was no significant difference in the results between Senior Secondary1 (SS1) students and Senior Secondary 2 (SS2) students and also between Senior Secondary 2 (SS2) and Senior Secondary 3 (SS3) students. The gender comparison shows that the male students obtained slightly higher score than their female counterparts. There was no significant difference in the performance of the male and female students. It seems there is an over reliance on paper and pencil computation neglecting intuitive understanding of numbers among these students....
Spacecraft maneuvers is a very important topic in aerospace engineering activities today. In a more\r\ngeneric way, a spacecraft maneuver has the objective of transferring a spacecraft from one orbit to\r\nanother, taking into account some restrictions. In the present paper, the problem of rendezvous\r\nis considered. In this type of problem, it is necessary to transfer a spacecraft from one orbit to\r\nanother, but with the extra constraint of meeting another spacecraft when reaching the final orbit.\r\nIn particular, the present paper aims to analyze rendezvous maneuvers between two coplanar\r\ncircular orbits, seeking to perform this transfer with lowest possible fuel consumption, assuming\r\nthat this problem is time-free and using four burns during the process. The assumption of four\r\nburns is used to represent a constraint posed by a real mission. Then, a genetic algorithm is used\r\nto solve the problem. After that, a study is made for a maneuver that will make a spacecraft\r\nto encounter a planet, in order to make a close approach that will change its energy. Several\r\nsimulations are presented....
The convergence of model-free adaptive control MFAC algorithm can be guaranteed when\r\nthe system is subject to measurement data dropout. The system output convergent speed gets\r\nslower as dropout rate increases. This paper proposes aMFAC algorithm with data compensation.\r\nThe missing data is first estimated using the dynamical linearization method, and then the\r\nestimated value is introduced to update control input. The convergence analysis of the proposed\r\nMFAC algorithm is given, and the effectiveness is also validated by simulations. It is shown that\r\nthe proposed algorithm can compensate the effect of the data dropout, and the better output\r\nperformance can be obtained....
This paper reports the findings from a study on the effect of operations in number sense proficiency of Senior Secondary School students in Bwari Area Council of the Federal Capital Territory (FCT), Abuja, Nigeria. A total of 300 Senior Secondary School students in Bwari Area Council of the Federal Capital Territory (FCT) Abuja, Nigeria participated in this study. A majority (63%) of these students obtained C and D grades in their respective end of term school examinations. The design for this study was quantitative in nature where the data on students’ number concept sense of numbers was collected using number concept in Number Sense Test adapted from McIntosh et al, (1997). The results from this study indicate that students obtained a percentage of success rates ranging from 49.5% to 55.4% across the levels. There was no significant difference in the results between Senior Secondary1 (SS1) students and Senior Secondary 2 (SS2) students and also between Senior Secondary 3(SS3) students. The gender comparison shows that the male students obtained slightly higher score than their female counterparts. There was no significant difference in the performance of the male and female students. It seems there is an over reliance on paper and pencil computation neglecting intuitive understanding of numbers among these students....
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