Non-natural metrics on the tangent bundle

Natural metrics provide a way to induce a metric on the tangent bundle from the metric on its base manifold. The most studied type is the Sasaki metric, which applies the base metric separately to the vertical and horizontal components. We study a more general class of metrics which introduces interactions between the vertical and horizontal components, with scalar weights. Additionally, we explicitly clarify how to apply our and other induced metrics on the tangent bundle to vector fields where the vertical component is not constant along the fibers. We give application to the Special Orthogonal Group SO(3) as an example.Published versio

Inhibiting factors affecting teachers’ implementation of the KBSM (revised) English language curriculum

This paper aims to discuss teachers’ degree of implementation of the KBSM (Revised) English Language Curriculum, introduced in 2003. It also sets to highlight the inhibiting factors that had impeded teachers’ implementation of the Skills Specifications or activities suggested in the Huraian Sukatan Pelajaran (HSP) Bahasa Inggeris Tingkatan Empat of the new curriculum. Firstly, the author finds that about 60 percent of the teachers obtained only a medium degree of implementation for 18 out of the 22 Skills Specifications. Secondly, the author concludes that among the prominent factors that had inhibited teachers’ implementation of the KBSM (Revised) English language curriculum in Malaysian classrooms were too many components of the new curriculum, hence leading to lack of understanding of the curriculum, lack of in-service training, time constraints and finally inadequate and irrelevant teaching materials

The dual origin of cultivation in coconut and its implications for breeding : [Abstract W494]

Coconut is cultivated throughout the tropical coasts and is integral part of the way of life of many human communities. There is no related wild species. Many coconut varieties were identified. Stature and mating system distinguish selfpollinating Dwarfs and cross-pollinating Talls. Within these types, varieties differ in terms of fruit color, size and morphology. Our work aimed to identify the genetic relationships between these varieties as well as the region where cultivation was initiated. It was also to elucidate its dissemination pathways. DNA was collected from 1322 individuals representing more than 100 populations from most of the producing countries. It was analyzed using a microsatellite kit. Results were interpreted in the light of historical information on human population movements. Software Structure identified two major groups. The largest and most diverse group (A) extended from South-east Asia to the whole Pacific. The other group (B) was present in India and on the Atlantic coasts. East Africa and the Western Indian Ocean showed evidence of introgression among groups. The frequency of group A alleles was higher in Madagascar and in the Comoros than in East Africa, reflecting austronesian migrations and arab trade in the region. Attempts to subdivide further diversity preserved group B but split group A into 4 populations. Three of them were centered on South-East Asia, Papua New Guinea (PNG) and the South Pacific without definite limit between them. Virtually all self-pollinating Dwarf coconuts were in the South-East Asian group suggesting that this region was the place of origin of dwarfism. The last population was found on the Pacific coast of Central America and was brought from the Philippines, probably at pre- Columbian times. Our results suggest that coconut cultivation was initiated separately in South Asia and in a region extending from South-East Asian and PNG. The high level of molecular differentiation between groups A and B suggests that gene exchange between India and Pacific was interrupted for a long period. Identifying QT alleles that were fixed during this period would provide breeders with efficient improvement strategies. (Texte integral

Performance of common-mode chokes

A low-cost method for experimental investigation of common-mode chokes for reducing high-frequency motor ground-currents of inverter-based drive systems of several hundred kW is presented. It provides a powerful tool during the design stage of such chokes to verify their predicted performance. The method draws from the mainly capacitive behavior of machines at very high frequencies. Results of experimental tests for drives with peak ground-current amplitudes of more than 60 Amperes, carried out on a 4 kW test-bed, are presented. They confirm the feasibility of such tests as well as the capability of small, inexpensive, single-turn chokes to effectively reduce the ground-current

Competency level of technological pedagogical contents knowledge (TPCK) framework amongst graduate teachers

This article propose a framework for educational technology based on Shulman’s formulation of ‘‘pedagogical content knowledge’’ and extend it to the integration of technology into it. It attempts to capture some of the essential qualities of teacher knowledge required for technology integration in teaching. Briefly, that thoughtful pedagogical uses of technology require the development of a complex, situated form of knowledge that we call Technological Pedagogical Content Knowledge (TPCK). The TPCK framework has much to offer to discussions of technology integration at multiple levels: theoretical, pedagogical, and methodological as well as the complex roles of, and interplay among, three main components of learning environments: content, pedagogy, and technology

Testing the Profitability of Simple Technical Trading Rules: A Bootstrap Analysis of the Italian Stock Market.

The aim of this paper consists in testing the profitability of simple technical trading rules in the Italian stock market. By means of a recently developed bootstrap methodology we assess whether technical rules based on moving averages are capable of producing excess returns with respect to the Buy-and-Hold strategy. We find that in most cases the rules are profitable and the excess return is statistically significant. However, the well-known problem of data-snooping, which seems to be confirmed by our analysis, requires some caution in the application of these methods.

Spatial models for flood risk assessment

The problem of computing risk measures associated to flood events is extremely important not only from the point of view of civil protection systems but also because of the necessity for the municipalities of insuring against the damages. In this work we propose, in the framework of an integrated strategy, an operating solution which merges in a conditional approach the information usually available in this setup. First we use a Logistic Auto-Logistic (LAM) model for the estimation of the univariate conditional probabilities of flood events. This approach has two fundamental advantages: it allows to incorporate auxiliary information and does not require the target variables to be independent. Then we simulate the joint distribution of floodings by means of the Gibbs Sampler. Finally we propose an algorithm to increase ex post the spatial autocorrelation of the simulated events. The methodology is shown to be effective by means of an application to the estimation of the flood probability of Italian hydrographic regions