1,357 research outputs found
Melody contour identification and instrument recognition using semitone mapping in Nucleus Cochlear Implant recipients
Cochlear implants (CIs) were originally aimed at restoring speech perception for patients with profound hearing loss. Many postlingually deafened CI patients report that music is not well perceived while others enjoy it. Music consists of complex sounds composed of tones with harmonic structure of overtones and temporal fine structure. The harmonic structure is not preserved by the current standard (Std) ACE (advanced combination encoders) mapping and the temporal fine structure is not well encoded. The mapping is believed to produce distortion due to compression oin the low frequency range.
In 2008 we proposed two new semitone (Smt) mappings (Smt-LF and Smt-MF) in two frequency ranges (130-1502 Hz and 440-5040 Hz) respectively (Omran et al. 2008). Smt mapping is expected to preserve the harmonic structure representation of overtones and this may improve melody recognition with CIs. In this paper two psychoacoustic experiments (melody contour identification (MCI) (Galvin et al. 2007) and instrument recognition (IR)) were conducted with three different conditions (Std, Smt-MF and Smt-LF mappings) with CI recipients by streaming processed stimuli directly to the implant.
The MCI test included five patterns (rising - rising falling - flat - falling rising – falling). Each pattern consisted of five tones; each tone had a fundamental frequency and four overtones. The lowest fundamental frequency of each pattern is called “root”. Signals had two different roots A3 (220 Hz) and A4 (440 Hz).
Proposed nine patterns with three roots (A3, A4 and A5) by Galvin et al. (2007) were examined in a pilot test. This test took a long time and the preliminary results showed a possibility to reduce the number of patterns to five and eliminate the fifth octave root (A5). In the IR test, four pairs of instruments (Trumpet and Trombone, Flute and Clarinet, Violin and Cello, Guitar and Piano) from four groups (Brass, Woodwind, Struck and String instruments) respectively were used.
MCI and IR tests were conducted with 8 CI recipients. Results from MCI tests showed an improvement with Smt mapping in respect to Std mapping or at least similar results. However, wrong identification occurred with notes having filtered out partials. CI recipients showed an increase in identifying melody contour patterns with Smt mappings. Instrument identification performance decreased with semitone mappings
Identifying Contextual Predictors Of Urban Park Utilization Among Inter-Ethnic Groups In Malaysia
Social interaction among diverse ethnic groups motivates people within communities to visit urban parks towards achieving social cohesion. Malaysians of different ethnic backgrounds spend their leisure time in urban parks because it offers opportunities for social interaction. The perception and requirement of attributes needed varies among the various ethnic groups of Malays, Chinese and Indians in order to be assured of their full utilization of the parks. This study investigates the urban park attributes that encourage the utilization of urban park by these three ethnic groups toward achieving social cohesion. Using a survey questionnaire method a total of 274 respondents were sampled at Batu Pahat urban parks in Johor, Malaysia. Afterwards, Structural Equation Modelling (SEM) was used to analyse and validate respondents’ perception of urban park utilization. The findings show that aesthetics, safety, lighting, maintenance and cleanliness in public spaces attracted people to visit the urban park and contributed towards social cohesion
Hyperinsulinism-hyperammonaemia syndrome: novel mutations in the GLUD1 gene and genotype-phenotype correlations
Background: Activating mutations in the GLUD1 gene (which encodes for the intra-mitochondrial enzyme glutamate dehydrogenase, GDH) cause the hyperinsulinism–hyperammonaemia (HI/HA) syndrome. Patients present with HA and leucine-sensitive hypoglycaemia. GDH is regulated by another intra-mitochondrial enzyme sirtuin 4 (SIRT4). Sirt4 knockout mice demonstrate activation of GDH with increased amino acid-stimulated insulin secretion.
Objectives: To study the genotype–phenotype correlations in patients with GLUD1 mutations. To report the phenotype and functional analysis of a novel mutation (P436L) in the GLUD1 gene associated with the absence of HA.
Patients and methods: Twenty patients with HI from 16 families had mutational analysis of the GLUD1 gene in view of HA (n=19) or leucine sensitivity (n=1). Patients negative for a GLUD1 mutation had sequence analysis of the SIRT4 gene. Functional analysis of the novel P436L GLUD1 mutation was performed.
Results: Heterozygous missense mutations were detected in 15 patients with HI/HA, 2 of which are novel (N410D and D451V). In addition, a patient with a normal serum ammonia concentration (21 µmol/l) was heterozygous for a novel missense mutation P436L. Functional analysis of this mutation confirms that it is associated with a loss of GTP inhibition. Seizure disorder was common (43%) in our cohort of patients with a GLUD1 mutation. No mutations in the SIRT4 gene were identified.
Conclusion: Patients with HI due to mutations in the GLUD1 gene may have normal serum ammonia concentrations. Hence, GLUD1 mutational analysis may be indicated in patients with leucine sensitivity; even in the absence of HA. A high frequency of epilepsy (43%) was observed in our patients with GLUD1 mutations
Wireless technology: current status and future directions
Wireless Technology is expected to be the dominant
mode of access technology in the future. Besides voice, a
new data range of services such as multimedia and high
speed data are being offered for delivery over wireless
network. Mobility will be seamless, realizing the concept
of persons' being in contact anywhere, at any time.
Throughout this paper, we review the long, interesting
development of wireless communication in the past,
examine the current progress in standards and
technologies, and finally discuss possible trends for
wireless communication solutions
Behavior of expanded polystyrene (EPS) blocks under cyclic pavement foundation loading
This study introduces a mechanism for initial assessment and future development to improve understanding of expanded polystyrene (EPS) behavior as a super-lightweight material for road construction. Large scale cyclic plate load tests on model pavements were performed. The effect of several factors including thickness of soil, thickness of subsequent EPS layers and density of EPS on the surface deformations, resilient modulus (Mr) and interlayer pressure transfer were investigated. The results indicated that, compared to a covering soil layer of 300 mm, the rut depth on the loading surface reduced by 13.5% and 40.8% when the soil thickness was increased by 33% and 100%, respectively. With a constant soil thickness, increasing the thickness of an upper (denser) EPS layer with respect to a bottom (softer) EPS layer, from 200 mm to 600 mm, would only result in a 20% decrease in the peak settlements after loading. Resilient modulus of the system was found to be dependent on soil thickness. A designer can choose an appropriate resilient modulus assuming the soil-EPS composite acts as subgrade or subbase. In order to extend the results to a wider range of geofoams, soils and layer thicknesses, a simple stress analysis method was also trialed
A probabilistic multi-objective approach for FACTS devices allocation with different levels of wind penetration under uncertainties and load correlation
This study presents a probabilistic multi-objective optimization approach to obtain the optimal locations and sizes of static var compensator (SVC) and thyristor-controlled series capacitor (TCSC) in a power transmission network with large level of wind generation. In this study, the uncertainties of the wind power generation and correlated load demand are considered. The uncertainties are modeled in this work using the points estimation method (PEM). The optimization problem is solved using the Multi-objective particle swarm optimization (MOPSO) algorithm to find the best position and rating of the flexible AC transmission system (FACTS) devices. The objective of the problem is to maximize the system loadability while minimizing the power losses and FACTS devices installation cost. Additionally, a technique based on fuzzy decision-making approach is employed to extract one of the Pareto optimal solutions as the best compromise one. The proposed approach is applied on the modified IEEE 30-bus system. The numerical results evince the effectiveness of the proposed approach and shows the economic benefits that can be achieved when considering the FACTS controller
Means of Developing Communication Between the Engineering Colleges and the Labor Market
The research aims at identifying the means of developing communication between the engineering colleges and the labor market by studying the many scientific sources, the previous studies and the working papers of a number of conferences, seminars, and workshops related to the research topic. Strengthened the relationship between engineering colleges and the labor market. The research adopted a descriptive method. The current research confirmed the adoption of the modern model of the advanced countries of the world in enhancing communication between the engineering colleges and the labor market, which is based on the integrated vision based on partnership. The research came out with a number of recommendations and suggestions
EFFICACY AND SAFETY OF ACETAMINOPHEN COMPARED TO TRAMADOL AFTER LAPAROSCOPIC CHOLECYSTECTOMY
Abstract Background: Laparoscopic cholecystectomy become widely popular because of its less postoperative pain produced compared to conventional cholecystectomy. The use of opioids postoperatively to reduce pain may be harmful and produce some adverse effects .Tramadol is a centrally acting opioid which is effective for postoperative analgesic pain but produce undesirable adverse effects the patients do not tolerate it so that intravenous acetaminophen could be helpful to optimize postoperative analgesia by reducing the requirement for opioids and their adverse effects.Method: A prospective randomized clinical trial was carried out on 27 adults undergoing elective laparoscopic cholecystectomy were randomly assigned to two groups in this study (13patients) to receive intravenously 1000mg acetaminophen and (14 patients) to receive intramuscularly tramadol 100mg postoperatively; visual analog scale (VAS) was utilized to asses pain severity and efficacy of analgesic agents. Pain scores were assessed at 0,2,4,6,8,10 and 12h after surgery the incidence of adverse effects was also assessed.Results: Over a period of 12hours, visual analog scale (VAS) scores were significantly lower in each group at each time interval compared to zero time; there is a non significant difference in pain score between the different groups; the incidence of adverse effects like nausea and vomiting was significant in tramadol group compared to acetaminophen group.Conclusion: Postoperative intravenous acetaminophen infusion of 1000mg is useful for reducing pain scores after elective laparoscopic cholecystectomy; it is effective and safe analgesic with less adverse effects compared to tramadol.  Key words: laparoscopic cholecystectomy, Acetaminophen, Tramadol, Postoperative analgesia.  Â
Recent trends and developments in conducting polymer nanocomposites for multifunctional applications
Electrically-conducting polymers (CPs) were first developed as a revolutionary class of organic compounds that possess optical and electrical properties comparable to that of metals as well as inorganic semiconductors and display the commendable properties correlated with traditional polymers, like the ease of manufacture along with resilience in processing. Polymer nanocomposites are designed and manufactured to ensure excellent promising properties for anti-static (electrically conducting), anti-corrosion, actuators, sensors, shape memory alloys, biomedical, flexible electronics, solar cells, fuel cells, supercapacitors, LEDs, and adhesive applications with desired-appealing and cost-effective, functional surface coatings. The distinctive properties of nanocomposite materials involve significantly improved mechanical characteristics, barrier-properties, weight-reduction, and increased, long-lasting performance in terms of heat, wear, and scratch-resistant. Constraint in availability of power due to continuous depletion in the reservoirs of fossil fuels has affected the performance and functioning of electronic and energy storage appliances. For such reasons, efforts to modify the performance of such appliances are under way through blending design engineering with organic electronics. Unlike conventional inorganic semiconductors, organic electronic materials are developed from conducting polymers (CPs), dyes and charge transfer complexes. However, the conductive polymers are perhaps more bio-compatible rather than conventional metals or semi-conductive materials. Such characteristics make it more fascinating for bio-engineering investigators to conduct research on polymers possessing antistatic properties for various applica-tions. An extensive overview of different techniques of synthesis and the applications of polymer bio-nanocomposites in various fields of sensors, actuators, shape memory polymers, flexible elec-tronics, optical limiting, electrical properties (batteries, solar cells, fuel cells, supercapacitors, LEDs), corrosion-protection and biomedical application are well-summarized from the findings all across the world in more than 150 references, exclusively from the past four years. This paper also presents recent advancements in composites of rare-earth oxides based on conducting polymer composites. Across a variety of biological and medical applications, the fact that numerous tissues were receptive to electric fields and stimuli made CPs more enticing
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