Classification of Malaysian vowels using formant based features

Automatic speech recognition (ASR) has made great strides with the development of digital signal processing hardware and software, especially using English as the language of choice. Despite of all these advances, machines cannot match the performance of their human counterparts in terms of accuracy and speed, especially in case of speaker independent speech recognition. In this paper, a new feature based on formant is presented and evaluated on Malaysian spoken vowels. These features were classified and used to identify vowels recorded from 80 Malaysian speakers. A back propagation neural network (BPNN) model was developed to classify the vowels. Six formant features were evaluated, which were the first three formant frequencies and the distances between each of them. Results, showed that overall vowel classification rate of these three formant combinations are comparatively the same but differs in terms of individual vowel classification

Effect of pH on growth and nitrogen fixation of Azotobacter Spp.

Three species o f Azotobacter were isolated from prawn-cum-paddy fields o f Kerala. These strains were found to have the optimum pH for growth and nitrogen fixation near or slightly above neutrality, i.e., in the pH range o f 7.0 to 8.

Determination of gross energy of feeds

The amount of heat, measured in calories, that is released when a substance is completely oxidized in a bomb calorimeter containing 25 to 30 atmospheres of oxygen, is called the gross energy (GE) of the substance. A sample of the material to be tested is weighed into a combustion capsule. The combustion capsule is placed in an oxygen bomb containing 25 to 30 atmospheres of oxygen. The oxygen bomb is covered with 2000 g of water in an adiabatic calorimeter. After the bomb and calorimeter have been adjusted to the same temperature, the sample is Ignited with a fuse wire. The temperature rise is measured under adiabatic conditions. From the hydrothermal equivalent of the calorimeter the temperature rise minus some small corrections for fuse wire oxidation and acid production, the caloric content of the sample is calculated

Lipid requirements of milkfish {Chanos chanos) fry

Feeding axperiments conducted in the laboratory on the fry of milkfish, Chanos chanos, with purified diets containing graded levels of lipids showed that 6%-lipid level induces the optimum food intake, maximum growth and best utilization of food and protein. Whereas the lipid levels higher than this optimum have led to increased fat deposition in the tissues, the lower levels have caused reduced growth and poor utilization of food and protein. An inverse relationship is observed between the moisture and lipid contents of the experimental fish. The diet containing 6% lipid has provided the fish with 1.09% saturated fatty acids, 1.56% mono-unsaturated acids, and 3.195% of poly-unsaturated fatty acids. The w6/w3 ratio of the diet was 2.43/0.762

Optimising the Active Sonar System Design

Designing an optimum sonar system for a given platform is based on analysing various parameters in their totality, establishing the constraints and assumptions relevant to the platform and the environment as well as on manipulating the design parameters to arrive at the sonar configuration that will maximise performance. In this paper, the design tradeoffs involved in the system design for an active sonar are discussed. A computer aided analysis for the 'first order' estimation of the sonar performance is presented. Typical results of the analysis in connection with the design for certain hypothetical systems are also included

Influence of probiotic bacterium Lactobacillus acidophilus on the survival and growth of pearl oyster Pinctada fucata spat

Combination of micro-alga Chaetoceros calcitrans and the probiotic bacterium Lactobacillus acidophilus evaluated at 1:1 and 1:2 levels revealed that in the probiotic treated group, Pinctada fucata spat registered significantly high survival of 79.7 and 89.0 % (P<0.05) respectively compared to that of 65.0 % survival in control. The probiotic treated groups also showed significant improvement in growth in terms of length and weight as compared to the control group. The probiotic treated spat attained a weight gain of 346.0 ± 1.57 mg (1:1 level) and 382.0 ± 11.76 mg (1:2 level) compared to 296.4 ± 9.04 mg in control group. The length in terms of dorso-ventral measurement (DVM) increased to 18.68 mm (1:1 level) and 19.6 (1:2 level) mm compared to 13.56 mm in control group

Guaiane sesquiterpenes from seaweed Ulva fasciata Delile and their antibacterial properties

Two new guaiane sesquiterpene derivatives, guai-2-en-10a-ol (1) and guai-2-en-10a-methanol (2), were chromatographically purified as major constituents of the CHCl3/CH3OH (1:1, v/v) soluble fraction of Ulva fasciata. Acetylation of 2 furnished guai-2-en-10a-methyl methanoate (3) with acetyl group at C11 position. The structures of the compounds were elucidated using one and two-dimensional NMR and mass spectrometric analysis. Compounds 2 and 3 exhibited significant inhibition to the growth of Vibrio parahaemolyticus with minimum inhibitory concentrations of 25 and 35 mg/mL, respectively. The electronegative C10 acetyl group with high polarisability (7.02� 10�24 cm3) in 3 appeared to withdraw electron cloud from substituted cycloheptyl ring and (R)-3-methylcyclohept-1-ene moiety, thus acting as the nucleophilic center of the molecule resulting in high bioactivity

Superconductivity in Ru substituted BaFe2-xRuxAs2

The occurrence of bulk superconductivity at ~22 K is reported in polycrystalline samples of BaFe2-xRuxAs2 for nominal Ru content in the range of x=0.75 to 1.125. A systematic suppression of the spin density wave transition temperature (TSDW) precedes the appearance of superconductivity in the system. A phase diagram is proposed based on the measured TSDW and superconducting transition temperature (TC) variations as a function of Ru composition. Band structure calculations, indicate introduction of electron carriers in the system upon Ru substitutiom. The calculated magnetic moment on Fe shows a minimum at x=1.0, suggesting that the suppression of the magnetic moment is associated with the emergence of superconductivity. Results of low temperature and high field Mossbauer measurements are presented. These indicate weakening of magnetic interaction with Ru substitutionComment: 20 pages 10 figure

On Security and reliability using cooperative transmissions in sensor networks

Cooperative transmissions have received recent attention and research papers have demonstrated their benefits for wireless networks. Such benefits include improving the reliability of links through diversity and/or increasing the reach of a link compared to a single transmitter transmitting to a single receiver (single-input single-output or SISO). In one form of cooperative transmissions, multiple nodes can act as virtual antenna elements and provide diversity gain or range improvement using space-time coding. In a multi-hop ad hoc or sensor network, a source node can make use of its neighbors as relays with itself to reach an intermediate node with greater reliability or at a larger distance than otherwise possible. The intermediate node will use its neighbors in a similar manner and this process continues till the destination is reached. Thus, for the same reliability of a link as SISO, the number of hops between a source and destination may be reduced using cooperative transmissions as each hop spans a larger distance. However, the presence of ma-licious or compromised nodes in the network impacts the benefits obtained with cooperative transmissions. Using more relays can increase the reach of a link, but if one or more relays are malicious, the transmission may fail. However, the relationships between the number of relays, the number of hops, and success probabilities are not trivial to determine. In this paper, we analyze this problem to understand the conditions under which cooperative transmissions fare better or worse than SISO transmissions. We take into consideration additional parameters such as the path-loss exponent and provide a framework that allows us to evaluate the conditions when cooperative transmissions are better than SISO transmissions. This analysis provides insights that can be employed before resorting to simulations or experimentation. © Springer Science+Business Media, LLC 2012