A New Approach to Abstract Syntax with Variable Binding

The permutation model of set theory with atoms (FM-sets), devised by Fraenkel and Mostowski in the 1930s, supports notions of ‘name-abstraction’ and ‘fresh name’ that provide a new way to represent, compute with, and reason about the syntax of formal systems involving variable-binding operations. Inductively defined FM-sets involving the name-abstraction set former (together with Cartesian product and disjoint union) can correctly encode syntax modulo renaming of bound variables. In this way, the standard theory of algebraic data types can be extended to encompass signatures involving binding operators. In particular, there is an associated notion of structural recursion for defining syntax-manipulating functions (such as capture avoiding substitution, set of free variables, etc.) and a notion of proof by structural induction, both of which remain pleasingly close to informal practice in computer science. Received October 2000 / Accepted in revised form April 2001     

Collaborative Localization for Multi-Robot System with Fault Detection and Exclusion Based on the Kullback-Leibler Divergence

Multi-robot system attracted attention in various applications in order to replace the human operators. To achieve the intended goal, one of the main challenges of this system is to ensure the integrity of localization by adding a sensor fault diagnosis step to the localization task. In this paper, we present a framework able, in addition of localizing a group of robots, to detect and exclude the faulty sensors from the group with an optimized thresholding method. The estimator has the informational form of the Kalman Filter (KF) namely Information Filter (IF). A residual test based on the Kullback-Leibler divergence (KLD) between the predicted and the corrected distributions of the IF is developed. It is generated from two tests: the first acts on the means and the second deals with the covariance matrices. Thresholding using entropy based criterion and Receiver Operating Characteristics (ROC) curve are discussed. Finally, the validation of this framework is studied on real experimental data from a group of robots.     

Evaluating the Use of Daily Care Notes Software for Older People with Dementia

There has been little research to investigate the impact of software to support the care for older people with dementia care. This article reports the evaluation of software adapted to support one key person-centered task for the care of older residents with dementia – recording and sharing daily care notes. The evaluation on the dementia wing of 1 residential home for over 6 months revealed that use of the software on mobile devices carried by the carers increased the number and volume of daily care notes recorded, but only for the types of content that were already being recorded by carers. Carers reported more advantages that resulted from daily care notes once in digital form than from the documenting task, as well as barriers to the use of mobile digital software to record daily care notes.     

Overflow probability in shared cell switched buffers

The ubiquity of the cell switching technique is a clear indication of its continued importance for the future of telecommunications worldwide. The performance of shared buffers in cell switches provides substantial improvement over switches with separate output buffers. The conventional approach to shared buffer analysis is numerical convolution; however, previous work provides an analytical solution based on the Chernoff bound. In this paper we develop a new closed-form expression for the cell loss probability in the shared buffer that offers superior accuracy, enhanced simplicity, and better generality     

Management of persistent filtering cicatrix following cataract extraction

We used a safe and simple surgical technique in the management of persistent filtering cicatrices after cataract extraction. The edematous, friable filtering cicatrix was excised entirely and a healthy fornix-based conjunctival flap was sutured over the fistula. Invariably, the fistula was very small, usually only large enough to admit a 27-gauge needle. Of the 27 eyes treated with this technique, there were two failures, but no other complications.     

Education for the optometric educator

Optometric education is faced with the need for new thinking in developing and training educators and new methods of financing their education. Establishing of research faculty and the instituting of research in present schools of optometry must be given a high priority in the future of optometric education.     

Effect of the Sugar Replacement by Citrus Fibre on the Physical and Structural Properties of Wheat-Corn Based Extrudates

Citrus fibre was used as a substitute for sucrose in the formulation of wheat-corn-based extrudates produced using twin screw extruder. Replacing 5 % sugar with an equal quantity of fibre resulted in an increase in die pressure, torque and specific mechanical energy (SME), and consequently the expansion ratio increased. A further increase in fibre content to 10 % (e.g. reducing sugar to 0 %) had little effect on the extrusion processing parameters. The microstructure of extrudates examined by X-ray computed tomography shows that the porosity of the extrudates increased with increasing fibre content, which was attributed to an increased number of large pores. As the citrus fibre content increased, the maximum force required to fracture the extrudate increased; however, the cell wall thickness decreased. This suggests that the fibre component may have contributed to the strength of the cell wall. This study demonstrated a potential utilisation of fibre from by-product of juice extraction as a source of dietary fibre in low sugar-extruded products.     

Pasting,thermal, gel texture,resistant starch and colour properties of unripe banana flour from 10 desert banana varieties cultivated in South Africa

Unripe banana flour is a potential commercial ingredient in various food products for increased resistant starch and reduced gluten contents. In the present study, the pasting (rapid visco-analysis), gel texture (penetration test), thermal (differential scanning calorimetry), colour (tri-stimulus colour indices) and the resistant starch properties of unripe banana flour produced from different dessert banana varieties (n?=?10) cultivated in South Africa, were analysed and juxtaposed to wheat and maize flour. The functional properties varied significantly (p?≤?0.05) between banana varieties, and from wheat and maize flours, to various extents. Selected functional property ranges of unripe banana, wheat and maize flours, respectively included; flour colour index (63.16–76.42, 77.34 and 80.96), paste viscosity (405.5–556.6, 124.7 and 115.6 RVU), gelatinization temperature (64.67–71.21, 71.11 and 69.95?°C), gel firmness (7.24–11.44?×?10^??2 N, 3.49?×?10^??2 N and 6.56?×?10^??2 N) and resistant starch content (19.9–47.4, 2.8 and 2.2% w/w). Multivariate analysis (principle component analysis) showed that the unripe banana flours from different varieties were distinguished from each other based on the pasting temperature. The unripe banana flours were distinguished from both wheat and maize flour based on breakdown and peak paste viscosities. The breakdown viscosity was the most positively related measure to the resistant starch content with a linear regression R-squared value of 0.898, indicating a significant role played by granule structure in resistance to enzymatic hydrolysis. The present research demonstrates that selection of appropriate dessert banana variety is important when replacing staple flours (wheat and maize) with unripe dessert banana flour as a functional ingredient.