161 research outputs found

    An evolutionary strategy based motion estimation algorithm for H.264 video codecs

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    In this paper, we propose a new motion estimation algorithm based on evolutionary strategy (ES) for the H.264 video codec applied to monoscopic video. The proposed technique applies in macroblock basis and performs a parallel local search for the motion vector associated with the minimum motion compensated residue. For this purpose (/spl mu/+/spl lambda/)-ES is used with heuristically and randomly generated population of initial motion vectors. Experimental results show that the proposed scheme can reduce the computational complexity up to 50% of the motion estimation algorithm used in the H.264 reference codec at the same picture quality. Therefore, the proposed algorithm provides a significant improvement in motion estimation in the H.264 video codec

    Soil water extraction pattern of coconut (Cococs nucifera L.) in relation to soil compaction

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    Effect of soil compaction on the gowth and activity of coconut roots in two soil series, namely, Andigama series (gravelly soil) and Madampe series (sandy loam soil) was studied. The effective root zone of coconut in relation to water sbsorption process under natural soil compaction were also investigated. Soil compactin and soil moisture absorption ability was determined using cone penetrometer and neutron scattering methods, respectively. Coconut root distributution in Andigama and Madampe series showed that 75%-80% of roots of adult coconut palms were localised in a depth ranging from 20 cm to 100 cm. About 5% of the roots were located beyond the 100 cm depth and 15% -20% was confined to the top layer (0-20 cm) of soil. Root growth of coconut in the two series did not show any significant differences. However, the root activity in the Madampe series, with respect to moisture absorption was higher that that of the Andigama series due to low compaction of the former. Results also showed that soil compaction higher than 250N/cm restricted the activity of coconut roots in the Andigama series for moisture absorption up to a distance of 2m away horizontally from the base of the tree and the highest moisture extraction was observed at m distance. High moisture extraction by coconut roots was confined to a depth ranging of 20 to 120 cm and of 20 to 250 cm in soils of Andigama and Madampe series, respectively, due to differences in soil compaction levels. It was condluded that soil compaction limits the water absorption ability of coconut roots vertically from the base of the tree, rather than coconut root growth and penetration

    Validation of a CT-free navigation system for the measurement of native acetabular alignment

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    Computer assisted surgery is becoming more frequently used in medical world. OrthoPilot Hip Suite CT-free navigation system (BBraun Aesculap) is one such computer assisted navigation system used for total hip replacement surgery. The validity of OrthoPilot system remains to be determined independent of the manufacturer. The main aims of this study were to investigate the accuracy of OrthoPilot data, while using surgical instruments and to confirm the suitability of the cup navigation algorithm. OrthoPilot was compared with the gold standard of a VICON movement analysis system. An aluminium pelvic phantom was machined with high accuracy to perform the experiments. Data were captured simultaneously from both OrthoPilot and VICON systems and acetabular angles were compared. Both systems produce comparable results for the distance between anatomical landmarks and acetabular angles. It can be concluded that data from OrthoPilot system, if used correctly, are sufficiently accurate for orthopaedic applications

    Efficient coding unit size selection based on texture analysis for HEVC intra prediction

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    Determining the best partitioning structure for a given Coding Tree Unit (CTU) is one of the most time consuming operations within the HEVC encoder. The brute force search through quadtree hierarchy has a significant impact on the encoding time of high definition (HD) videos. This paper presents a fast coding unit size decision-taking algorithm for intra prediction in HEVC. The proposed algorithm utilizes a low complex texture analysis technique based on the local range property of a pixel in a given neighborhood. Simulation results show that the proposed algorithm achieves an average of 72.24% encoding time efficiency improvement with similar rate distortion performance compared to HEVC reference software HM12.0 for HD videos

    Effective coding unit size decision based on motion homogeneity classification for HEVC inter prediction

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    © 2014 IEEE. Determining the best partitioning structure for a given Coding Tree Unit (CTU) is one of the most time consuming operations within the HEVC encoder. The brute force search through quad tree hierarchy has a significant impact on the encoding time especially on high definition (HD) videos. This paper presents a fast coding unit size decision-taking algorithm for inter prediction in HEVC. The proposed algorithm uses a motion homogeneity based classification approach utilizing RD cost as a feature vector. Simulation results show that the proposed algorithm achieves an average of 73.25% encoding time efficiency improvement with similar rate distortion performance compared to HEVC HM12.0 reference software

    A new chemical method for purification and surface modification of Sri Lankan vien graphite

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    Sri Lanka has its own demarcated possession for the high quality vein graphite containing 95-98 % of initial purity of carbon.Presently Sri Lankan vein graphite is exported as a cheap raw material without any value addition. The present study focuses to find a cost effective and convenient new chemical method for the graphite purification and to modify the graphite surface using alkali chloride solutions for improving performance of a graphite electrode (for negative electrode) of batteries. Collected vein graphite samples were powdered and prepared samples (10 g of <53 μm) were treated for acid digestion method with a mixture of 5 % of HF, Con.H2SO4& Con.HNO3. 3.50 g of portions graphite powders were separately mixed with 100 ml of 0.1% LiCl, 0.1% KCl and 0.1 % NaCl aqueous solutions for preparing of surface modified graphite. The carbon content of the Needle Platy Graphite (NPG) variety has the highest carbon content and the purity of the samples has been enhanced after acid digestion treatment by removing impurities. The FTIR analysis proved that many of impurity related functional group bands have been removed from the surface modified NPG.The Lithium, Sodium and Potassium Chloride coatings were capable to improve the electric conductivity performance

    ESTIMATION OF LIQUID EMISSION LOADS FROM INDUSTRIES WITHIN THE KELANI RIVER BASIN

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    The Kelani River could be ranked as the largest recipient of industrialeffluents of the country. The pollution burden of this effluent is quite diverseranging from food manufacturing industries to heavy industrial dischargesfrom textile factories, tanneries, soap and cleaning preparationsmanufacturing plants and rubber factories. An attempt was made to estimatethe liquid emission loads released annually into the Kelani River Basin by theabove sectors.Liquid emission loads were assessed in terms of Biological Oxygen Demand(BOD) and Total Suspended Solid (TSS) content. In certain cases specialparameters such as Chemical Oxygen Demand (COD) and Chromium werealso assessed because of chemical contamination and hazardous potential. Inestimating emission loads Rapid Assessment Procedure and the Date BadeUrban Pollution Control Model were used as the guide.The results of the study indicate that the Kelani River receives 766.73 tons ofBOD and 462.04 tons of TSS annually from the above mentioned industrialsectors and 3.8 million cubic meters of annual industrial wastewater volume.In addition, the tanneries and leather finishing factories discharge untreatedeffluent, which is contaminated with chromium, a hazardous heavy metalhaving bioaccumulation potential, into the river basin. The amount ofchromium released into the river is as high as 6.36 tons while the COD loadfrom rubber manufacturing sector is 48.71 tons annually

    EFFECT OF THE PERIOD OF THE YEAR WHICH EXPLANTS WERE COLLECTED ON SHOOT GROWTH AND THE CALLUS FORMATION OF THE TISSUE CULTURED JACK FRUIT

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    A method for rapid propagation of mature Jack fruit from apical meristem culture wasdeveloped. Apical meristems were estahlished in Modified Campbell and Durzan mediumsupplemented with NAA and ISA. Cultures were suh cultured in every 4 weeks interval inorder to reduce the accumulation of phenolic compounds. Reducing the accumulatedphenolics at the base of the explant enhanced the growth rate. There was a significantdifference in the growth performance of shoots and callus produced according to the periodof the year in which explants were collected.60% of the apical meristems cultured in modified CD medium supplemented with IBA andNAA produced shoots in November to December period. It was only 30% when the apiceswere cultured in April to May months and decreased to 20% in June - July months. Theshoots produced in November - December period showed a higher vigour (in number ofleaves per shoot. mean leaf width and mean shoot length) than those produced in othermonths. Since jackfruit show seasonal changes in fruit bearing and shedding of leaves. itcan be suggested that the difference in growth performances of tissues cultured in artificialculture media would have been effected by endogenous rhythms. It has been observed thatthe callus production depends on the incubation temperature. Callus was induced at thebase of the shoot hy increasing the incubation temperature from 2S± IIIC to 30± Ifie.Growth of the callus was also retarded hy accumulated phenolic compounds in themedium.

    AVIFAUNAL DIVERSITY IN A TEA PLANTATION ECOSYSTEM IN THE UP-COUNTRY OF SRI LANKA

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    A survey on birds was conducted at Mattakelle Tea Estate with the objective of assessing the significance of a given tea plantation ecosystem in maintaining avifaunal diversity. Seven different habitats were identified in the ecosystem namely home garden, seasonal stream, small scale reservoir, Eucalyptus forest, wetland, tea field and secondary forest. The monitoring was conducted from January to June 2010 using line transect method. 28 counts were made for each habitat. Besides, activities of birds, feeding habits and food recourses were observed.61 species of birds including  9 species of endemics and 10 species of migrants were recorded. One globally threatened species Kashmir Flycatcher (Ficedula subrubra) and 12 nationally threatened species were observed. Among the habitats, the highest species count of 62% was recorded in  home garden habitat where Shannon index (H’) = 3.03 and Evenness (J) =0.46. Species diversity and the evenness of the secondary forest were comparable to tea field indicating H’= 2.86 and J=0.43; H’ =2.77 and J= 0.46 respectively.  The avifaunal diversity was relatively low in the rest.The study revealed that each of the habitats provided unique niches and supported maintenance of natural diversity. Vegetation structure and the complexity of the ecosystem in tea plantations play a vital role in sustaining  avifaunal diversity. Several conservation measures such as increasing plant diversity, introduction of shade trees, conduct of good agricultural practices and prevention from setting fire are recommended to protect and conserve avifaunal diversity
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