424 research outputs found

    Time division multiplex of discrete air-conditioning units

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    POS1: Poster Session (1): P-025In Hong Kong, air-conditioning (a/c) is a major energy end-user in building services. Nowadays, operation modes of various a/c are uncoordinated. Hence, the diversity of this major energy usage is coarse and uncontrolled. The project shall utilize Time-Division-Multiplex (TDM) concept to regulate this. Through research effort, a better diversity of energy utilization in premises will be achieved. The peak demand of current, the sum of steady load currents and the cable heat loss will then be reduced. The cable capacity will be better utilized, and the potential of reserve in buildings will then be significantly enhanced. Beyond this study, the TDM concept can be extended to other appliances, for example, kitchen appliances and storage-type water heater. It is also envisaged that the project becomes an integral part to smart metering communication management. This shall call for a new culture to regulate the load demand pattern with a better diversity in premises.postprintThe International Conference on Electrical Engineering (ICEE) 2008, Okinawa, Japan, 6-10 July 2008

    The treatment of patients suffering from benign paroxysmal positional vertigo with oscillation

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    Conference Theme: Challenges to specialists in the 21st centurypublished_or_final_versio

    Advances in the management of hearing problems

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    The recent advances in the management of hearing problems are in three areas; firstly, early detection and diagnosis of hearing loss in children so that rehabilitation can be started whenever appropriate. Secondly, prostheses can be made from better tolerated material and employed for surgical reconstruction of the ossicular chain in the middle ear. Finally, the rehabilitation of those patients who have sensorineural problems can be enhanced by the programmable hearing aids. For the unfortunate patients who suffer from profound deafness, a cochlear implantation can be carried out to enable them to regain functional hearing.published_or_final_versio

    Fabrication of Photovoltaic Cell From Rhenium Containing Polymer

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    Photovoltaic devices were fabricated using rhenium bis(arylimino) acenaphthene (DIAN) complex containing poly(p-phenylenevinylene). These polymers absorb strongly in the visible region at ca. 440-550 nm. In addition, this type of transition metal based polymers have been shown to exhibit large photo-sensitivity due to the presence of the rhenium complex, which has a relatively long-lived Metal-to-Ligand Charge Transfer (MLCT) character. By using this type of polymers, the metal content can be adjusted easily by simply changing the monomer feed ratio. Moreover, the excited state properties and electronic absorption properties can be modified by varying the structure of the diimine ligand coordinated to the metal. This approach allows us to fine-tune the absorption spectra of the polymers by employing different types of rhenium complex derivatives. PEDOT:PSS and PTCDI were used as the hole and electron transport layers, respectively. The ITO/PEDOT:PSS/DIAN-PPV/PTCDI/Al devices were found to exhibit photovoltaic response under the illumination of AMI solar radiation. The short-circuit current ISC, open-circuit voltage V OC, and the fill factor FF were measured to be 38 μA/cm 2, 0.93 V and 0.21 respectively. Another photovoltaic device was prepared with the structure ITO/PEDOT:PSS/DIAN-PPV:TiO2/PTCDI/Al and its photovoltaic properties were studied. The presence of TiO2 will assist the electron transport of the DIAN-PPV to the PTCDI, in which the electrons can be collected at the aluminium electrode. The short-circuit current ISC open-circuit voltage VOC, and the fill factor FF were measured to be 51 μA/cm2, 1.18 V and 0.12 respectively. It was observed that the power conversion efficiency of photovoltaic devices related closely to the rhenium content and the structure of the rhenium complex used.published_or_final_versio

    Stridor in Asian infants: assessment and treatment

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    Stridor is the main symptomof upper airway obstruction in infants. It can be congenital or acquired, acute or chronic. Pathologies can be located from the nose down to the trachea. Common causes include laryngomalacia, vocal cord palsy, subglottic stenosis, tracheal anomaly, laryngeal cleft, vascular and lymphatic malformation, laryngeal papillomas, craniofacial abnormalities and even head and neck tumours. In this paper, we will discuss our approach to infants with stridor including assessment with flexible and rigid endoscopy and treatments to various conditions in a tertiary centre. Causes of stridor in infants undergoing rigid laryngotracheobronchoscopy in Queen Mary Hospital, University of Hong Kong Medical Centre between 2005 and 2011 will be retrospectively reviewed. Treatments according to various conditions will be discussed. Successful management of these neonates requires accurate diagnosis, early intervention, and multidisciplinary care by ENT surgeons, paediatricians, and paediatric anaesthetists.published_or_final_versio

    Operator entanglement of two-qubit joint unitary operations revisited: Schmidt number approach

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    Operator entanglement of two-qubit joint unitary operations is revisited. Schmidt number is an important attribute of a two-qubit unitary operation, and may have connection with the entanglement measure of the unitary operator. We found the entanglement measure of two-qubit unitary operators is classified by the Schmidt number of the unitary operators. The exact relation between the operator entanglement and the parameters of the unitary operator is clarified too.Comment: To appear in the Brazilian Journal of Physic

    Multitrait analysis of quantitative trait loci using Bayesian composite space approach

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    <p>Abstract</p> <p>Background</p> <p>Multitrait analysis of quantitative trait loci can capture the maximum information of experiment. The maximum-likelihood approach and the least-square approach have been developed to jointly analyze multiple traits, but it is difficult for them to include multiple QTL simultaneously into one model.</p> <p>Results</p> <p>In this article, we have successfully extended Bayesian composite space approach, which is an efficient model selection method that can easily handle multiple QTL, to multitrait mapping of QTL. There are many statistical innovations of the proposed method compared with Bayesian single trait analysis. The first is that the parameters for all traits are updated jointly by vector or matrix; secondly, for QTL in the same interval that control different traits, the correlation between QTL genotypes is taken into account; thirdly, the information about the relationship of residual error between the traits is also made good use of. The superiority of the new method over separate analysis was demonstrated by both simulated and real data. The computing program was written in FORTRAN and it can be available for request.</p> <p>Conclusion</p> <p>The results suggest that the developed new method is more powerful than separate analysis.</p
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