Fast K-dimensional tree algorithms for nearest neighborsearch with application to vector quantization encoding

Fast search algorithms are proposed and studied for vector quantization encoding using the K-dimensional (K-d) tree structure. Here, the emphasis is on the optimal design of the K -d tree for efficient nearest neighbor search in multidimensional space under a bucket-Voronoi intersection search framework. Efficient optimization criteria and procedures are proposed for designing the K-d tree, for the case when the test data distribution is available (as in vector quantization application in the form of training data) as well as for the case when the test data distribution is not available and only the Voronoi intersection information is to be used. The criteria and bucket-Voronoi intersection search procedure are studied in the context of vector quantization encoding of speech waveform. They are empirically observed to achieve constant search complexity for O(log N) tree depths and are found to be more efficient in reducing the search complexity. A geometric interpretation is given for the maximum product criterion, explaining reasons for its inefficiency with respect to the optimization criteria     

Optimal capacitor allocation in power systems

Static capacitors are installed at specific locations in large power systems for minimising power losses and to ensure quality of the supply system. It has been found that the number of units in each capacitor bank can be considerably reduced by suitable choice of transformer tap settings and generator voltage magnitudes, thereby reducing the cost of installation of capacitors. This paper presents an efficient method for finding the optimal values for the number of units in each capacitor bank and their locations for the purpose of reducing power losses and for ensuring the quality of the supply system. This is accomplished by optimal allocation of all reactive power sources in the system in a coordinated fashion by varying the number of units in each capacitor bank and generator voltage magnitudes and transformer tap setting positions.The problem is formulated as an optimisation problem with the objective function representing the revenue resulting from reduction in power losses, taking into account the cost due to interest and depreciation on the static capacitor installation and the constraints based on physical and technical limitations on the system. The problem falls in the category of Mixed Integer Linear Programming (M.I.L.P.) and is solved by decomposing the problem into two smaller subproblems viz., a pure integer programming problem in binary variables and a linear programming problem. The solutions of these subproblems are coordinated to get the solution of the original problem. Very fast convergence is obtained by preventing zigzagging of the solution about the optimal point. All these result in considerable savings in computer time and memory. The proposed model has been applied to sample systems and the results presented and discussed.     

Excision of ultraviolet and gamma ray products of the 5,6-dihydroxy-dihydrothymine type by nuclear preperations of xeroderma pigmentosum cells

Monomeric products of the 5,6-dihydroxy-dihydrothymine type are produced in the DNA by both ultraviolet and ionizing radiations. The capacity of nuclear preparations from normal and Xeroderma pigmentosum (XP) cells (Complementation groups A, B, C and D) to excise such products from ultraviolet or gamma-irradiated T7DNA was comparable and was independent of radiation induced strand breaks.     

Influence of long term feeding of palm oil on the lipid composition of perirenal adipose tissue in rats

The composition of perirenal adipose tissue in Wistar strain of rats fed palm oil (PO) fat at 5% and 20% in diet for a period of 18 weeks was studied. Peanut oil (PNO) at 5% and 20% were used as controls. Under the experimental conditions, the saturation index was higher in animals fed diet containing PO compared to those fed PNO. There was no significant difference with reference to 12:0, 14:0 and 18:1 fatty acid levels, whereas linoleic acid (18:2) showed a proportional relationship between the intake and perirenal adipose tissue levels. There was a significant correlation of dietary intake of linoleic acid and the U/S ratio in the adipose tissue. Linoleic acid (18:2, n6) levels were increased in 20% PNO groups as compared to those fed PO. However, palmitoleic acid (16:1) did not show a proportional relationship between the intake and adipose tissue levels. Thus, our studies show that more saturated fatty acids are incorporated in the PO group than in the PNO groups at the end of 18 weeks feeding.     

Optimisation of catalytic system for tar mitigation in biomass producer gas

ABSTRACT

The producer gas from biomass gasification is an upcoming power-generating technique for meeting the power requirements of the rural society. The performance of the biomass gasifier can be raised by mitigating tar in producer gas. Tar is highly carcinogenic and tends to condense at room temperature, which results in blocking and fouling of the downstream equipment. In this research, nano-structured SiO₂-supported Ni pellets are used as catalysts to reduce the tar content in producer gas from a biomass gasifier. Further, Cerium (Ce) and Praseodymium (Pr) are reinforced with Ni–SiO₂ pellets to improve the catalytic activity for tar mitigation. The Taguchi methodology is employed to rank and predict the optimal catalytic factor among the catalyst weight, gas feed rate (GF) and bed temperature (BT) for the tar cracking. The experimentation is done according to the L₉ design table and the mathematical model for tar concentration is developed with the adequacy (R²) of 99.93%. The optimal catalytic system with 9?g of Pr, 0.01?l/s GF and 775°C of BT has reduced the tar concentration from 27 to 0.17?mg/Nm³, i.e. the efficiency of tar mitigation achieved is around 99.3%.     

Solution equilibrium characteristics of electroless copper deposition on thermally-activated palladium-catalysed polyimide substrates

Solution equilibrium characteristics of two electroless copper baths containing EDTA and tartrate as the complexing agents were studied as functions of pH. Equilibrium diagrams were constructed for both Cu-tartrate and Cu-EDTA systems. It was determined that copper is chiefly complexed as Cu2L2 in acidic conditions and as Cu(OH)2L2–4 in alkaline conditions in the tartrate bath, and as CuA–2 in the EDTA bath, where L and A are the complexing tartrate and EDTA ligands, respectively. Electroless copper deposition rates were studied from a tartrate bath on thermally activated palladium-catalysed polyimide substrates as functions of copper and formaldehyde concentrations, and pH.     

Experimental Investigation on Surface and Machining Characteristics of Micro ED Milling of Ti-6Al-4 V with Different Nano Powder Mixed Dielectrics

Silicon - Micro ED milling is a micro machining technique for machining of high-quality micro parts on the electrically conductive material. Achieving a good surface finish with higher material...     

Characteristics of a calcium–milk coagulum

The texture, microstructure and composition of a milk coagulum obtained by coagulating milk with calcium chloride and heat were evaluated. A direct relationship was established between the microstructure and texture of the calcium–milk coagulum. The microstructure was comprised of casein micelles that were interlinked by appendages or fused with each other depending on the nature of the pre-heat treatment employed. The casein micellar network also entrapped fat globules. The pre-heat treatment of milk and the pH of milk during coagulation affected the hardness, adhesiveness, protein content and microstructure of the calcium–milk coagulum significantly. This study characterises a calcium–milk coagulum as a novel dairy product which differs from an acid coagulum in texture, microstructure and composition.