Elementary school teachers\u27 beliefs about teaching and learning mathematics : selected case studies in Taiwan.

Mathematics curriculum innovation has been launched in Taiwan recently in order to reflect the changing needs of the 21st century. The underlying assumptions of reform are: a learner-centered approach, emphasis on confluent education, and a problem-solving & reasoning approach. Research has revealed that teachers\u27 beliefs can negatively interact with curriculum reform. On the other hand, some studies document that beliefs have little effect on instructional behavior. Therefore, this study attempts to investigate three questions: (1) what are the teachers\u27 beliefs about the teaching and learning of mathematics in Taiwanese elementary schools and in what ways are teachers\u27 beliefs congruent with the ongoing trend of reform; (2) what is the general picture of teachers\u27 mathematical instructional practices in Taiwanese elementary schools and in what ways are these instructional practices congruent with the ongoing trend of reform; and (3) what is the relationship between teachers\u27 beliefs and their instructional practices? Basically, this study combines qualitative and quantitative methods in collecting and analyzing data. That is, teacher interviews and questionnaires were administered in order to understand teachers\u27 beliefs about teaching and learning mathematics while observational checklists and naturalistic field observations were used to portray instructional behavior. The major findings of this study are: (1) Elementary school teachers\u27 beliefs tend to hold with the traditional absorption learning theory and seem incongruent with the undergoing curriculum reform. (2) The instructional practices tend to reflect a traditional teacher-centered classroom and also seem incongruent with the launched reform. (3) Teachers\u27 beliefs about teaching and learning play a vital role in shaping their instructional behavior; the situational constraints merely play a minor role. In light of the above findings, some implications such as teacher education were drawn to broaden teachers\u27 beliefs

Characterizing Intermittency of 4-Hz Quasi-periodic Oscillation in XTE J1550-564 using Hilbert-Huang Transform

We present the time-frequency analysis results based on the Hilbert-Huang transform (HHT) for the evolution of a 4-Hz low-frequency quasi-periodic oscillation (LFQPO) around the black hole X-ray binary XTE J1550-564. The origin of LFQPOs is still debated. To understand the cause of the peak broadening, we utilized a recently developed time-frequency analysis, HHT, for tracking the evolution of the 4-Hz LFQPO from XTE J1550 564. By adaptively decomposing the ~4-Hz oscillatory component from the light curve and acquiring its instantaneous frequency, the Hilbert spectrum illustrates that the LFQPO is composed of a series of intermittent oscillations appearing occasionally between 3 Hz and 5 Hz. We further characterized this intermittency by computing the confidence limits of the instantaneous amplitudes of the intermittent oscillations, and constructed both the distributions of the QPO's high and low amplitude durations, which are the time intervals with and without significant ~4-Hz oscillations, respectively. The mean high amplitude duration is 1.45 s and 90% of the oscillation segments have lifetimes below 3.1 s. The mean low amplitude duration is 0.42 s and 90% of these segments are shorter than 0.73 s. In addition, these intermittent oscillations exhibit a correlation between the oscillation's rms amplitude and mean count rate. This correlation could be analogous to the linear rms-flux relation found in the 4-Hz LFQPO through Fourier analysis. We conclude that the LFQPO peak in the power spectrum is broadened owing to intermittent oscillations with varying frequencies, which could be explained by using the Lense-Thirring precession model.Comment: 27 pages, 9 figures, accepted for publication in The Astrophysical Journa

The Emergent Landscape of Detecting EGFR Mutations Using Circulating Tumor DNA in Lung Cancer.

The advances in targeted therapies for lung cancer are based on the evaluation of specific gene mutations especially the epidermal growth factor receptor (EGFR). The assays largely depend on the acquisition of tumor tissue via biopsy before the initiation of therapy or after the onset of acquired resistance. However, the limitations of tissue biopsy including tumor heterogeneity and insufficient tissues for molecular testing are impotent clinical obstacles for mutation analysis and lung cancer treatment. Due to the invasive procedure of tissue biopsy and the progressive development of drug-resistant EGFR mutations, the effective initial detection and continuous monitoring of EGFR mutations are still unmet requirements. Circulating tumor DNA (ctDNA) detection is a promising biomarker for noninvasive assessment of cancer burden. Recent advancement of sensitive techniques in detecting EGFR mutations using ctDNA enables a broad range of clinical applications, including early detection of disease, prediction of treatment responses, and disease progression. This review not only introduces the biology and clinical implementations of ctDNA but also includes the updating information of recent advancement of techniques for detecting EGFR mutation using ctDNA in lung cancer

A New Measure of Cluster Validity Using Line Symmetry

[[abstract]]Many real-world and man-made objects are symmetry, therefore, it is reasonable to assume that some kind of symmetry may exist in data clusters. In this paper a new cluster validity measure which adopts a non-metric distance measure based on the idea of "line symmetry" is presented. The proposed validity measure can be applied in finding the number of clusters of different geometrical structures. Several data sets are used to illustrate the performance of the proposed measure.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[incitationindex]]EI[[ispeerreviewed]]Y[[booktype]]紙本[[booktype]]電子版[[countrycodes]]TW