Implementation of the Trigonometric LMS Algorithm using Original Cordic Rotation

The LMS algorithm is one of the most successful adaptive filtering algorithms. It uses the instantaneous value of the square of the error signal as an estimate of the mean-square error (MSE). The LMS algorithm changes (adapts) the filter tap weights so that the error signal is minimized in the mean square sense. In Trigonometric LMS (TLMS) and Hyperbolic LMS (HLMS), two new versions of LMS algorithms, same formulations are performed as in the LMS algorithm with the exception that filter tap weights are now expressed using trigonometric and hyperbolic formulations, in cases for TLMS and HLMS respectively. Hence appears the CORDIC algorithm as it can efficiently perform trigonometric, hyperbolic, linear and logarithmic functions. While hardware-efficient algorithms often exist, the dominance of the software systems has kept those algorithms out of the spotlight. Among these hardware- efficient algorithms, CORDIC is an iterative solution for trigonometric and other transcendental functions. Former researches worked on CORDIC algorithm to observe the convergence behavior of Trigonometric LMS (TLMS) algorithm and obtained a satisfactory result in the context of convergence performance of TLMS algorithm. But revious researches directly used the CORDIC block output in their simulation ignoring the internal step-by-step rotations of the CORDIC processor. This gives rise to a need for verification of the convergence performance of the TLMS algorithm to investigate if it actually performs satisfactorily if implemented with step-by-step CORDIC rotation. This research work has done this job. It focuses on the internal operations of the CORDIC hardware, implements the Trigonometric LMS (TLMS) and Hyperbolic LMS (HLMS) algorithms using actual CORDIC rotations. The obtained simulation results are highly satisfactory and also it shows that convergence behavior of HLMS is much better than TLMS.Comment: 12 pages, 5 figures, 1 table. Published in IJCNC; http://airccse.org/journal/cnc/0710ijcnc08.pdf, http://airccse.org/journal/ijc2010.htm

Energy efficient virtual machine provisioning in cloud data centers

A cloud data center consumes a great amount of electrical energy, resulting in a high level of carbon footprint. The reduction of electrical power consumption cuts down operational costs, and also improves system reliability for cloud based data centers. Data center power consumption is a critical issue that could be solved by consolidating servers' workload and turning off idle physical servers. We propose a heuristic based resource allocation policy for cloud based data centers in order to reduce operational costs. Our proposed technique shows that efficient resource allocation greatly reduces energy consumption, which leads to minimize operational costs. One of the more significant findings to emerge from this study is that, based on CPU utilization and live migration, proposed algorithm helps to minimize energy costs. The present study provides additional evidence with respect to environmental issues

An investigation of Pakistani university teacher-educators’ and student-teachers’ perceptions of the role and importance of inquiry-based pedagogy in their professional learning experiences in initial teacher education

This research is motivated by a paradigm shift in Initial Science Teacher Education in Pakistan, which places emphasis on the use of inquiry-based pedagogy as a key method for improving student-teachers’ understanding of science. In the light of this key role for inquiry-based pedagogy, this study explores the perceptions of teacher-educators and student-teachers who are participating in an initial teacher education (ITE) program in a university in Pakistan. The main aims of the study are to explore (a) their perceptions about the components for inquiry-based pedagogy which are required to be undertaken properly in the classroom; (b) their perceptions of the role and importance of inquiry-based pedagogy and (c) their perceptions of the barriers that impede the practice of inquiry-based approaches. The study uses a methodological triangulation to gather data from science teacher-educators and student-teachers, employing four research tools: a teacher-educators’ questionnaire, a student-teachers’ questionnaire, semi-structured interviews with 20 science teacher-educators, and two focus groups with small groups of science student-teachers. Though, the researcher’s role as an insider helped in collecting robust and extensive data due to a personal familiarity with the native setting, it also brought challenges in conducting the teacher-educators’ interviews. The analysis of data from both teacher-educators and student-teachers converged on the overarching themes of the role of inquiry-based pedagogy in ITE, the relationship between inquiry and science literacy and the barriers impeding the practice of inquiry-based pedagogy. Overall, it became clear that the conceptualization of inquiry-based learning with teacher-educators and student-teachers was rather limited. Nonetheless, the results of this study indicate that most teacher-educators were positive about the role and importance of inquiry-based pedagogy in ITE. The majority of teacher-educators appreciated their role as a facilitator of the learning process using inquiry and reported that they had developed an appreciation of the benefits of teaching science using inquiry-based pedagogy. Furthermore, teacher-educators strongly indicated an intention to use inquiry-based science teaching strategies in ITE in science though they tended to rely on questions as their main activity rather than using a range of inquiry-based instructional strategies. Moreover, the majority of teacher-educators reported that continued practice in teaching science courses and/or teaching method courses had contributed to their developing a fair understanding of inquiry-based pedagogy in science. The teacher-educators and student-teachers appreciated that inquiry-based pedagogy should be used in ITE because it helps in developing learning. The teacher-educators responded positively regarding the role of inquiry in developing science literacy and in enhancing the procedural understanding of student-teachers in science. Though most of the findings were supported by student-teachers’ responses from student-teachers’ questionnaires and focus groups, a gap was noted between the teacher-educators’ perceptions of the use of inquiry-base pedagogies and the student-teachers’ perceptions of their actual experiences in the science classroom in the responses given in the student-teachers’ focus groups. The results indicate that a majority of teacher-educators and students reported several serious barriers to using inquiry-based pedagogy. These were exam-based assessment, text-based curriculum in science courses, insufficient time, a lack of resources and a lack of university support. Furthermore, the majority of teacher-educators reported that the curriculum allows only limited exposure to inquiry when teacher-educators are burdened with a large teaching load as well as a shortage of time, limited resources and big classes. The teacher-educators commented that assessment allows them little autonomy in assessing student-teachers’ levels of science learning. Consequently, teacher-educators’ lack of motivation regarding the process of inquiry-based strategies was reported, which resulted in the reduced use of inquiry-based strategies. Thus, teacher-educators’ lack of motivation, difficulties in managing inquiry-based lessons and student-teachers’ low levels of confidence in using inquiry were all reported as more minor barriers which could be removed with a continued practice of inquiry-based approaches. Student-teachers’ perceptions from their questionnaires’ and focus groups’ data support the teacher-educators’ perceptions of the role and importance of inquiry-based pedagogy. Moreover, the majority of teacher-educators responded that student-teachers should be encouraged to develop an understanding of the process of inquiry. The emergent themes were discussed in the light of the existing literature in order to highlight similarities, as well as distinctive features in a Pakistani context. Finally, recommendations concerning the importance of inquiry-based pedagogy in science in ITE, the arrangement of resources, teacher-educators’ professional development, and preparation for student-teachers are presented for the attention of teacher-educators, the University administration, and Higher Education Authorities

Apel/Ref-lのレドックス制御機能は抗原提示細胞を介してヘルパーT細胞の反応を調節する

学位論文要約山形大

Social Safety and Security of Women Workers in Garments Sector of Bangladesh

Bangladesh is the fastest developing country in the world today Among various sectors responsible for this contribution the highest important is garments or RMG The generation of foreign currency employment opportunity are the basics done by RMG at present Most of this employment is poor women workforce at a very little cost While the garments sector is dependent on this labor force the employers are not providing them the facilities according to labor law Women s social occupational rights are at risk today This study has gone through the observation of women workers social safety security conditions with the solution of the problems prevailing in RMG secto

Exploratory Study of Textile Undergraduates’ Knowledge and Perception towards Eco-Friendly Clothing in Bangladesh

Environmentalism leads to the concept of eco-friendly clothing (EFC) and its popularity is advancing all over the world. In-depth knowledge acquisition regarding EFC has become a fundamental requirement for Bangladeshi Textile undergraduates as they are the future professionals in the EFC sector. To ascertain the knowledge level and perception of the Bangladeshi textile undergraduates regarding EFC was the aim of this study. In this exploratory study, a self-administered questionnaire was used to collect data through purposive sampling from the students enrolled into the Bangladesh undergraduate Textile Engineering programme. The respondents were 282 students of the fourth year of different universities located in Dhaka city. Descriptive statistics were used to represent the findings of the research. The results showed that 82.3% of the respondents were informed about EFC, 35.8% were knowledgeable regarding EFC raw materials and 53.02% were cognisant about the production process. 89.4% of the respondents expected one particular course on EFC in curriculum and 94% wanted to contribute towards EFC in the future. The study revealed that undergraduates have a knowledge gap regarding EFC, while their willingness to learn and contribute is very optimistic. The findings suggested that the evaluation and modification of the curriculum for EFC and incorporation of EFC courses can lessen this salient gap