澳门特区免费幼儿教育政策研究

澳门特区自2007～2008学年开始实施15年免费教育,即9年义务教育、3年高中教育和3年学前教育免费.研究者运用网络调查及访谈法,对澳门特区免费幼儿教育政策进行研究,结果发现:(1)免费幼儿教育政策只适用于6家公办幼儿园和42家加入免费教育学校系统的私立幼儿园.(2)7家未加入免费教育学校系统的私立幼儿园需缴学费、补充服务费和选择性服务费,但可获政府发放的学费津贴和书簿费.家长很满意这一政策,并表示愿意继续送孩子上收费的私立幼儿园.(3)受访园(校)长、家长及教师对澳门的免费幼儿教育政策都很满意,教师特别满意政府推出的幼儿园教师津贴.(4)免费幼儿教育政策对私立园所的影响有所不同:有些私立园所为了生存而选择加入免费教育学校系统,有些私立园所则为了校政自主而选择不加入免费教育学校系统.客观上,高收费门槛令不同阶层家庭的幼儿自然分流.     

Some aspects of science education in Britain: a comparative study

This article gives a broad picture of science education in Britain, starting with school pupils of about 11 years of age and concluding at the Ph.D. level. In the main it considers the education system from the point of view of students preparing for professional scientific work in basic and applied research as well as those who will leave the system at first degree level for a variety of occupations, ranging from school teaching to development and marketing posts in industry. The article is not directly concerned with the education and training of engineers and technologists. The British system is compared briefly with the educational patterns of several western European countries and the USA.     

On the notions of ambiguity and information loss

One of the fundamental problems in information science is to distinguish various objects (such as books or journal articles) on the basis of associated values (such as authors and titles). Where the values fail to distinguish two distinct objects we say that the objects are ambigious under the given value assignment. To obtain a measure of ambiguity, it is only necessary to count the number of ways that the objects can be arranged for each set of ambiguous objects, multiply these counts and take logarithms. It is shown that such an approach leads to a measure in the formal sense and that the measure depends only on the definition of equality of values so that it can be simply extended to sets of values and ordered sets of values. It is also shown that it is possible to construct a function of ambiguity that one can call “information” and that the information loss that occurs when distinct values are grouped into equivalence classes (as in the use of search and sort keys) is also a measure. Finally, it is shown that ambiguity and information as here defined are directly related to Shannon's definition of “information” thus tieing this approach to that portion of information theory associated with the derivation of optimal distributions frequently used in information science models.     

External quality assessment for the RIA of thyroid related hormones: Second phase

An external quality assessment was conducted to assess the performance of various laboratories for RIA of thhyroid related hormones in two phases. In the first phase thirty five laboratories participated. At the end of first phase a meeting cum workshop was organised to discuss the results of first phase, difficultires faced by the participants and pinpoint the short oming. A second phase was then initiated with an objective of improvement in the performance, if any, where twelve samples from four pools were distributed to twenty four laboratories who participated for the second phase. The overall return of the results increased significantly from 71.8% (1586/2208) for the first phase to 92.4% (732/792) for the second phase. The inter laboratory %CV for T₃, T₄ and TSH were lower during the second phase (30.6%, 19.0% and 31.6% respectively) as compared to those observed during first phase (36.3%, 22.7% and 52.8% respectively). Similarly, there was an improvement in reproducibility of ALTM as %CV for T₃, T₄ and TSH decreased from 6.0%, 9.8% and 13.4% respectively to 4.5%, 4.6% and 8.5% respectively. The individual performances of the participating laboratories viz. bias, variability of bias and imprecision also showed a trend towards improvement as percent laboratories having desirable or acceptable results for T₃, T₄ and TSH increased from 10.7%, 60.7% and 0.0% respectively to 20.8%, 66.7% and 22.2% respectively. External quality assessment thus appears to be beneficial in assessing the performane of a laboratory in comfparison with other laboratories and indeed helps in improving the performance.     

Resistive pulse sensing of magnetic beads and supraparticle structures using tunable pores

Tunable pores (TPs) have been used for resistive pulse sensing of 1 μm superparamagnetic beads, both dispersed and within a magnetic field. Upon application of this field, magnetic supraparticle structures (SPSs) were observed. Onset of aggregation was most effectively indicated by an increase in the mean event magnitude, with data collected using an automated thresholding method. Simulations enabled discrimination between resistive pulses caused by dimers and individual particles. Distinct but time-correlated peaks were often observed, suggesting that SPSs became separated in pressure-driven flow focused at the pore constriction. The distinct properties of magnetophoretic and pressure-driven transport mechanisms can explain variations in the event rate when particles move through an asymmetric pore in either direction, with or without a magnetic field applied. Use of TPs for resistive pulse sensing holds potential for efficient, versatile analysis and measurement of nano- and microparticles, while magnetic beads and particle aggregation play important roles in many prospective biosensing applications.     

Robust block second order sliding mode control for a quadrotor

This paper presents the design of a controller based on the block control technique combined with the super twisting control algorithm for trajectory tracking of a quadrotor helicopter. A first order exact differentiator is used in order to estimate the virtual control inputs, which simplifies the control law design. In addition, the wind parameter resulting from the aerodynamic forces is also estimated in order to ensure robustness against these unmatched perturbations. The stability and finite time convergence of the exact differentiator have been recently proved by means of Lyapunov functions, and therefore the stability analysis of the proposed controller has been carried out along the same lines. The performance and effectiveness of the proposed controller are tested in a simulation study taking into account external disturbances.