Sintering and characterisation of nano-sized yttria-stabilised zirconia

A study has been conducted on the pressure-less sintering of the ZrC>2- Y2O3 system that contains 3 mol% Y2O3, and the effect that the temperature / time relationship has on the properties of the final product. Experiments were performed on two types of commercially available, nano-sized, ZrC>2 - 3mol% Y2O3 (3Y-TZP) powders. An unstabilised zirconia powder was also investigated for comparison purposes. Particle size analysis of these powder yield particle sizes ranging from 1.29 |xm to 1.78 pm, suggesting that the particles are heavily prone to agglomeration in water. BET specific surface area analysis showed the powders to be nano-sized as determined using equivalent spherical diameter theory. The density of the powders was measured using helium gas pycnometry. DTA/TGA analysis indicates that binder burnout occurs on heating in the range 300-440°C. Shrinkage and densification rate characteristics of the powders during sintering was investigated using dilatometry. One of the powders demonstrated full shrinkage during isothermal sintering; the other did not. The point of maximum densification rate differed by approximately 100°C for these powders. A dramatic expansion associated with the tetragonal to monoclinic transformation on cooling from 1400°C is observed by dilatometry for unstabilised zirconia powder sample but not for stabilised powder samples. This indicates that the sintered samples retain in tetragonal phase on cooling to room temperature. Pressureless conventional sintering and two-step sintering were used to sinter pressed discs. The density of discs which were sintered across a temperature range of 1350°C to 1550°C varies between 5.72 g/cm3 and 6.03 g/cm3, corresponding to 97.40% and 99.10% of theoretical density respectively. Density as high as 98.85% of theoretical was recorded for twostep sintering applying holding time of 16 h. Vickers hardness values increased with increasing sintering temperature. Fracture toughness measurements were carried out. X-ray diffraction analysis confirmed that sintered discs were fully tetragonal. Microstructural analysis of sintered samples was conducted to assess microstructural changes with respect to sintering temperature

TermEval: an automatic metric for evaluating terminology translation in MT

Terminology translation plays a crucial role in domain-specific machine translation (MT). Preservation of domain-knowledge from source to target is arguably the most concerning factor for the customers in translation industry, especially for critical domains such as medical, transportation, military, legal and aerospace. However, evaluation of terminology translation, despite its huge importance in the translation industry, has been a less examined area in MT research. Term translation quality in MT is usually measured with domain experts, either in academia or industry. To the best of our knowledge, as of yet there is no publicly available solution to automatically evaluate terminology translation in MT. In particular, manual intervention is often needed to evaluate terminology translation in MT, which, by nature, is a time-consuming and highly expensive task. In fact, this is unimaginable in an industrial setting where customised MT systems are often needed to be updated for many reasons (e.g. availability of new training data or leading MT techniques). Hence, there is a genuine need to have a faster and less expensive solution to this problem, which could aid the end-users to instantly identify term translation problems in MT. In this study, we propose an automatic evaluation metric, TermEval, for evaluating terminology translation in MT. To the best of our knowledge, there is no gold-standard dataset available for measuring terminology translation quality in MT. In the absence of gold standard evaluation test set, we semi-automatically create a gold-standard dataset from English--Hindi judicial domain parallel corpus. We trained state-of-the-art phrase-based SMT (PB-SMT) and neural MT (NMT) models on two translation directions: English-to-Hindi and Hindi-to-English, and use TermEval to evaluate their performance on terminology translation over the created gold standard test set. In order to measure the correlation between TermEval scores and human judgments, translations of each source terms (of the gold standard test set) is validated with human evaluator. High correlation between TermEval and human judgements manifests the effectiveness of the proposed terminology translation evaluation metric. We also carry out comprehensive manual evaluation on terminology translation and present our observations

Bangladesh and Regional Connectivity : Best Practices from Global Experiences

South Asia, economic integration, Bangladesh, transport costs

The Verbal and Non Verbal Signals of Depression -- Combining Acoustics, Text and Visuals for Estimating Depression Level

Depression is a serious medical condition that is suffered by a large number of people around the world. It significantly affects the way one feels, causing a persistent lowering of mood. In this paper, we propose a novel attention-based deep neural network which facilitates the fusion of various modalities. We use this network to regress the depression level. Acoustic, text and visual modalities have been used to train our proposed network. Various experiments have been carried out on the benchmark dataset, namely, Distress Analysis Interview Corpus - a Wizard of Oz (DAIC-WOZ). From the results, we empirically justify that the fusion of all three modalities helps in giving the most accurate estimation of depression level. Our proposed approach outperforms the state-of-the-art by 7.17% on root mean squared error (RMSE) and 8.08% on mean absolute error (MAE).Comment: 10 pages including references, 2 figure

Self-oscillating optical comb generator based on optoelectronic oscillator

This work is focused on two promising concepts of microwave photonics- optoelectronic oscillators and optical frequency comb generators, and their use to generate a self-oscillating optical comb. In particular we develop a recirculating loop topology in which a Mach-Zehnder modulator is modulated recursively via a secondary loop that acts as a self-homodyne input

Measurement of Antenna Radiation Pattern using Injection Locking Technique

This paper presents practical results using injection locking to synchronize the local oscillator on a wireless device enabling antenna measurements to be made in a modern anechoic chamber, overcoming the need to connect a cable to the device under tes

Benefits of active transmit balanced antenna fed by differential power amplifier

A differential amplifier feeding a balanced antenna is investigated experimentally. This approach would suit modern RFIC design rather than using a 50Ω unbalanced connection. As such the balun or power-combining network is eliminated resulting in a compact RF front-end design with wider bandwidth and lower losses. Experimental result shows that this technique promises higher output power compared to conventional feeding approach while using same RFIC and same power supply