Achieving greater anonymity in network latency

Each lnternet communication leaves trails that can be followed back to the user. Notably, anonymous communication schemes are purposed to hide users＇ identity as to personal, source, destination location and content information. Notably, no network capability is in existence to completely negate anonymity leakage in network latency[~l, thus, the minimization of anonymity leakage in network latency becomes critically salient. The purpose of this paper is to investigate network latency anonymity leaks, and propose practical techniques for their reduction. In this direction, the author investigate the following technical question： What implementation techniques can be configured to truly reduce anonymity leaks using deployable systems and exploiting the popular Tor security strategies.     

Processing and Development of Corrosion Resistance Surface-Active Thin Film Nanocellulose Composite Coatings for Mild Steel Protection

Protection of Metals and Physical Chemistry of Surfaces - Mild steels are applied in the construction of oil platforms and pipelines due to their ease of formability, machinability, good mechanical...     

Characterization of video codecs as autoregressive moving averageprocesses and related queueing system performance

A method of characterizing video codec sources in asynchronous transfer mode (ATM) networks as an autoregressive moving average (ARMA) process is described. Measurements of long-term mean and the autocorrelation function of cell interarrival times allow the parameter estimation of the ARMA model. The video source is then described by ARMA model. Furthermore, it is shown that the multiplexed stream of video cells is also an ARMA process. Such a cell stream is then applied to a model of a queuing system to obtain performance measures of the system. Perturbation analysis is then performed on the functional behavior of the queuing system by appropriate perturbation of the model parameters to determine cell waiting time sensitivity due to slight variations of the input process     

Motion estimation with object based regularisation

A dynamic programming based matching method for motion estimation. That optimises a Bayesian maximum likelihood function in a 3-D optimisation space, is presented. The Bayesian function consists of a matching cost and an object based 2-D regularisation cost. The method gives results more accurate than block-based matching since the motion boundaries are close to the actual object boundaries     

Energy-saving potentials of some local trees

The energy-saving potentials of some common tropical trees are presented. The experimental setup consists of a tree and sixteen (16) 0.05 cm by 0.05 cm dry wood of height 3 m which served as a stake. Each of the dry woods has two 0.001-mm-thick galvanized steel plates (0.3 cm by 0.3 cm), which served as the heated surface, nailed at heights of 1.3 and 2.6 m from the ground level. The plates are insulated at the back side with plywood, thus leaving only one side exposed to the direct effect of solar heating. The woods were installed at equal distances from the tree trunk such that the uncovered sides of the plates face east, west, north, and south. Temperatures of the plate at 1-h intervals were recorded from 08:00 and 17:00 h and subsequently used to compute energy absorbed by each plate. Four trees, Dogon Yaro (Azadirachta indica.), mango (Mangifera indica), velvet tamarind (Dialium indum), and oil bean (Pentacletra macrophylla), were used for the study. Results obtained showed that a reduction in solar space heating by up to 79 % can be achieved, depending on the position of the tree relative to the building. This corresponds to a saving in energy of up to 1050 kWh/year or 22 % of the annual energy consumption in a typical average residential building in Nigeria. Thus, proper tree planting is recommended for reduced residential energy consumption.     

Design improvements for a collector/generator/adsorber of a solid adsorption solar refrigerator

A study of the effects of different collector design parameters on the performances of a solar powered solid adsorption refrigerator is presented. The refrigerator uses activated carbon/methanol as the adsorbent/refrigerant pair. The study was undertaken using a computer simulation program developed from a transient analysis of the system. The parameters tested are the collector plate emissivity/absorptivity combination, adsorbent packing density, tube spacing, outer tube outside diameter, adsorbent thermal conductivity, heat transfer coefficient at adsorbent/tube interface, and adsorbent tube/collector plate materials combination. Two performance indicators namely, condensate yield and coefficient of performance (COP) were used in the study as figures of merit. A multiple regression technique was used to correlate the performance indicators with the collector parameters through a quadratic relation. Consequently an objective function, suitable for selecting optimal values of the parameters is defined, subject to specified constraints. Selecting the COP as the preferred indicator parameter, optimization was then carried out. Improvements in the ranges of 29–38% for COP and 26–35% for condensate yield were obtained with optimal choices of tube spacing, adsorbent packing density and collector plate/adsorbent tube material combinations.     

Effect of substituting cerium-rich mischmetal with lanthanum on high temperature properties of die-cast Mg–Zn–Al–Ca–RE alloys

Mg–Zn–Al–Ca–RE alloys have been found to be promising materials for substituting aluminum alloys used for automatic transmission case applications in the automobile industry. Particularly, Mg–0.5%Zn–6%Al–1%Ca–3%RE (ZAXE05613) alloy exhibits comparable creep resistance as ADC12 die-casting aluminum alloy that is currently used for automatic transmission case applications. Changing the rare earth (RE) content of the alloy from mischmetal to lanthanum gives a further improvement in the creep properties of the alloy. Lanthanum addition results in the crystallization of a large amount of acicular Al₁₁RE₃ (Al₁₁La₃) compound along the grain boundaries as well as across the grain boundaries and this effectively controls grain boundary sliding and dislocation motion in the vicinity of the grain boundaries. As a result, die-cast ZAXLa05613 alloy exhibits a higher creep resistance than that of ZAXE05613 alloy.     

Tumor presence at resection boundaries and lymph-node metastasis in bronchial carcinoma patients

A prospective study was performed analyzing the bronchial resection boundaries of 120 patients operated on for lung carcinoma. The resection boundary, maximum tumor diameter, distance between tumor and resection boundary, and lymph-node stage were analyzed by serial sections of the surgical specimens (lobes and lungs). The following results were obtained: 20/120 cases (17%) displayed microscopic tumor invasion of the resection boundary (R1 status), most frequently adenocarcinoma (21%). The R1 status was closely associated with the distance between tumor and resection boundary and postsurgical lymph-node state (pN stage): all 8 tumors excised at distance 1 mm or less from the bronchial resection boundary revealed bronchial submucous tumor growth, whereas none of the tumors located more than 20 mm from the resection boundary was found to display tumor invasion of the bronchial boundary. Curative resection was noted in all 40 tumors operated at pNO stage and in only 11 cases (69%) of tumors with distant lymph-node metastases (pN3 stage). No relationship between tumor infiltration of the resection boundary and type of resection was seen. The data indicate that a) intra-operative control of bronchial resection boundaries is necessary in all lung-carcinoma patients with central tumor localization less than 20 mm from the proposed resection boundary; b) a "safety distance" between resection boundary and tumor boundary is of specific importance in bronchial carcinoma with lymph-node metastases.     

Mean focal length of an aberrated lens

We outline an approach for the calculation of the mean focal length of an aberrated lens and provide closed-form solutions that show that the focal length of the lens is dependent on the presence of defocus, x-astigmatism, and spherical aberration. The results are applicable to Gaussian beams in the presence of arbitrary-sized apertures. The theoretical results are confirmed experimentally, showing excellent agreement. As the final results are in algebraic form, the theory may readily be applied in the laboratory if the aberration coefficients of the lens are known.     

Generalized beam quality factor of aberrated truncated Gaussian laser beams

We outline a theory for the calculation of the beam quality factor of an aberrated laser beam. We provide closed-form equations that show that the beam quality factor of an aberrated Gaussian beam depends on all primary aberrations except tilt, defocus, and x-astigmatism. The model is verified experimentally by implementing aberrations as digital holograms in the laboratory.