Head of the line arbitration of packet switches with combined input and output queueing

A single-stage non-blocking N × N packet switch is considered. Data units may be stored before switching at the inputs as well as after switching at the outputs. Some output buffering capacity is intended to achieve high throughput, whereas an additional input buffering capacity keeps losses due to input-buffer overflow reasonably low. The paper studies the impact on performance of the head of the line arbitration policy, i.e. the sequence which is used to transfer data units from the heads of input queues to each output queue. The investigation is based on two performance measures: the average delay and the maximum throughput of the switch. Closed-form expressions for the FCFS, LCFS and the ROS policies are obtained. The result of the average delay with the FCFS policy leads to a lower bound, and that with the LCFS policy to an upper bound for the average delay, corresponding to an arbitrary symmetric policy which does not use information related to the state of the input queues. It is shown that the maximum throughput does not depend on the head of the line arbitration policy. It depends only on the output-buffer size and the packet-size distribution. The cases of fixed and exponentially distributed packet sizes are studied. The effects of asymmetric policies which result in different behaviours of some of the input queues is also considered.     

Effect of bovine skim milk and whey on monocyte function

Previous studies have documented the ability of bovine milk to inhibit lymphocyte proliferation in response to mitogens. It is not known whether inhibition of lymphocyte proliferation is mediated through the action of monocytes. To address this question, we examined the ability of bovine skim milk and whey to affect monocyte function with emphasis on expression of major histocompatibility class II antigens and production of interleukin-1 by monocytes. Data showed that expression of major histocompatibility complex class II molecules and production of interleukin-1 by monocytes were not altered when monocytes were cultured in the presence of bovine skim milk or whey. Thus, it is unlikely that the suppressive effect of milk on lymphocyte proliferation could be mediated through alterations in the expression of major histocompatibility class II molecules or in production of interleukin-1 by monocytes. The role of other monocyte antigens or secretory products, however, should also be evaluated.     

Industrial espionage

The rapid developments in micro-electronics technology have opened the way to an unprecedented increase in commercial and industrial espionage. Electronic devices are capable of eavesdropping on private conversation between people and people, people and computers, computer and computer. These devices are hard to detect thus resulting in an invasion of privacy and the theft of priviledged information.It is widely recognized that information is a resource with economic value. Information processing crimes highlight the need to accept the existence of these crimes, to analyze the risks, and to apply the techniques and technology available to combat industrial/commercial espionage and computer crime.     

Growth of thin Ag films produced by radio frequency magnetron sputtering

Thin Ag films in the thickness range D = 14–320 nm were deposited by radio frequency magnetron sputtering on glass substrates at room temperature inside a vacuum chamber with base pressure of about 5 × 10^− 6 Pa. The growth of the films was studied via X-ray diffraction and atomic force microscopy experiments. The two techniques are complementary and give us the opportunity to study the surface roughness, the statistical distribution and the average value of the grain size, as well as the texture of the samples. It is shown that the film roughness increases negligibly within the first 60 atomic layers of growth. The thicker films (D 300 nm) develop a nanocrystalline structure with a root mean square roughness of about 2.5 nm. The grain size evolves linearly with the thickness from 9.4 nm at D = 54 nm to 31.6 nm at D = 320 nm.     

New compounds: antitumor activity of 3beta-hydroxy-13alpha-amino-13,17-seco-5alpha-androstan-17-oic-13,17-lactam 4-[p-[bis(2-chloroethyl)amino]phenyl]butyrate

3beta-Hydroxy-13alpha-amino-13,17-seco-5alpha-androstan-17-oic-13,17-lactam 4-[p[bis(2chloroethyl)amino]phenyl]butyrate was prepared by reacting 4-[p-[bis(2-chloroethyl)amino]phenyl]butyryl chloride hydrochloride with 3beta-hydroxy-13alpha-amino-13,17-seco-5alpha-androstan-17-oic-13,17-lactam. They cytostatic action of the ester was investigated on two tumor systems (B16 melanoma on C57 b1 mice and T8-Guerin on rats).     

Distribution of plasminogen and plasmin in fractions of bovine milk.

The relative amounts of immunoreactive plasminogen and active plasmin in different fractions of bovine milk were examined. Raw milk was centrifuged to separate skim, cream, and a somatic cell pellet. Skim milk was centrifuged to separate milk serum and casein micelles. Milk fat globule membranes were isolated from the cream fraction of bovine milk. Proteins from somatic cells were isolated following sonication of the cells. Western blot analysis showed the presence of several forms of plasminogen in bovine milk. The predominant forms of plasminogen identified following electrophoresis under nonreducing conditions were proteins with approximate molecular weights of 88,000, 152,000, and 160,000. The predominant forms of plasminogen identified after electrophoresis under reducing conditions were two proteins with approximate molecular weights of 88,000 and 50,000. The highest amount (82% of the total plasminogen), as determined by an ELISA, was associated with the casein fraction. Lower plasminogen concentrations were associated with the serum, cream fractions, and milk fat globule membranes. The SDS-PAGE of the cream and milk fat globule membranes indicated that some casein was present in both fractions. Thus, the low plasminogen concentrations in these fractions may be associated with the caseins there. No immunoreactive plasminogen was present in the somatic cells. Active plasmin was present in the same milk fractions in which plasminogen was detected: casein, serum, and cream.     

Power Efficient Video Multipath Transmission over Wireless Multimedia Sensor Networks

This paper proposes a power efficient multipath video packet scheduling scheme for minimum video distortion transmission (optimised Video QoS) over wireless multimedia sensor networks. The transmission of video packets over multiple paths in a wireless sensor network improves the aggregate data rate of the network and minimizes the traffic load handled by each node. However, due to the lossy behavior of the wireless channel the aggregate transmission rate cannot always support the requested video source data rate. In such cases a packet scheduling algorithm is applied that can selectively drop combinations of video packets prior to transmission to adapt the source requirements to the channel capacity. The scheduling algorithm selects the less important video packets to drop using a recursive distortion prediction model. This model predicts accurately the resulting video distortion in case of isolated errors, burst of errors and errors separated by a lag. Two scheduling algorithms are proposed in this paper. The Baseline scheme is a simplified scheduler that can only decide upon which packet can be dropped prior to transmission based on the packet’s impact on the video distortion. This algorithm is compared against the Power aware packet scheduling that is an extension of the Baseline capable of estimating the power that will be consumed by each node in every available path depending on its traffic load, during the transmission. The proposed Power aware packet scheduling is able to identify the available paths connecting the video source to the receiver and schedule the packet transmission among the selected paths according to the perceived video QoS (Peak Signal to Noise Ratio—PSNR) and the energy efficiency of the participating wireless video sensor nodes, by dropping packets if necessary based on the distortion prediction model. The simulation results indicate that the proposed Power aware video packet scheduling can achieve energy efficiency in the wireless multimedia sensor network by minimizing the power dissipation across all nodes, while the perceived video quality is kept to very high levels even at extreme network conditions (many sensor nodes dropped due to power consumption and high background noise in the channel).     

Effect of high-pressure treatment at various temperatures on indigenous proteolytic enzymes and whey protein denaturation in bovine milk

The objective of the present study was to determine the effect of high pressure (HP) processing (200, 450 and 650 MPa) at various temperatures (20, 40 and 55 degrees C) on the total plasmin plus plasminogen-derived activity (PL), plasminogen activator(s) (PA) and cathepsin D activities and on denaturation of major whey proteins in bovine milk. Data indicated that transfer of both PL and PA from the casein micelles to milk serum occurred at all pressures utilized at room temperature (20 degrees C). In addition to the transfer of PL and PA from micelles, there were reductions in activities of PL (16-18%) and PA (38-62%) for the pressures 450 and 650 MPa, at room temperature. There were synergistic negative effects between pressure and temperature on residual PL activity at 450 and 650 MPa and on residual PA activity only at 450 MPa. Cathepsin D activity in the acid whey from HP-treated milk was in general baroresistant at room temperature. The residual activity of cathepsin D decreased significantly at 650 MPa and 40 degrees C and at the pressures 450 and 650 MPa at 55 degrees C. Synergistic negative effects on the amount of native beta-lactoglobulin were observed at 450 and 650 MPa and on the amount of native alpha-lactalbumin at 650 MPa. There were significant correlations between enzymatic activities (PL, PA and cathepsin D) and the residual native beta-lactoglobulin and alpha-lactalbumin in bovine milk. In conclusion, HP significantly affected the activity of indigenous proteolytic enzymes and whey protein denaturation in bovine milk. Reduction in activity of indigenous enzymes (PL, PA and cathepsin D) and transfer of PL and PA from the casein to milk serum induced by HP is expected to have a profound effect on cheese yield, proteolysis during cheese ripening and quality of UHT milk during storage.     

Gradient-based Pareto front approximation applied to turbomachinery shape optimization

Engineering with Computers - Multi-objective optimization has been rising in popularity, especially within an industrial environment, where several cost functions often need to be considered during...