On the Capacity Bounds of Undirected Networks

In this work we improve on the bounds presented by Li&Li for network coding gain in the undirected case. A tightened bound for the undirected multicast problem with three terminals is derived. An interesting result shows that with fractional routing, routing throughput can achieve at least 75% of the coding throughput. A tighter bound for the general multicast problem with any number of terminals shows that coding gain is strictly less than 2. Our derived bound depends on the number of terminals in the multicast network and approaches 2 for arbitrarily large number of terminals.Comment: 5 pages, 5 figures, ISIT 2007 conferenc

Shear design of HSC beams with combination of links and horizontal web steel

The existing recommendations in Eurocode 2 and the British Code of Practice for the shear design of beams are derived from research conducted essentially on normal-strength concrete (NSC) with cube strengths up to 50 MPa, and it was found that the shear strengths of high-strength concrete (HSC) members made with limestone aggregate are below the characteristic resistances of identical NSC members. Previous experimental tests have also shown that significant differences exist in the angle of crack of shear failure of NSC and HSC. This paper presents data from five beam tests, which demonstrate that HSC with limestone aggregate has a reduced shear strength compared with NSC made with gravel and thus shows a gap in knowledge in the design approach to shear resistance of HSC beams. Previous investigations have suggested that horizontal web steels can contribute to the overall shear resistance of a reinforced concrete member in conjunction with the other constituents, concrete, tension and shear steel. The paper also presents data from tests on 11 beam tests and shows that the shear resistance of HSC beams is highly dependent on dowel action resulting from horizontal web bars positioned at the centre of the depth of the beam. Past attempts to quantify this dowel action are investigated and an improved design rule is proposed

The effect of tool fixturing quality on the design of condition monitoring systems for detecting tool conditions

Condition monitoring systems of machining processes are essential technology for improving productivity and automation. Tool wear monitoring of cutting tools is one of the important applications in this area. In this paper, the effect of collet fixturing quality on the design of condition monitoring systems to detect tool wear is discussed. The paper investigates the difference in the system's behaviour and the changes in the condition monitoring system when the cutting tool is not rigidly fastened to the collet. A group of sensors, namely acoustic emission, force, strain, vibration and sound, are used to design the condition monitoring system. Automated Sensor and Signal Processing Selection (ASPS) approach1 is implemented to address the effect of the tool holding device (collet) on the monitoring system and the most sensitive sensors and signal processing method to detect tool wear. The results prove that the change in the fixturing quality could have significant effect on the design of the condition monitoring system and the behaviour of the system

Effect of Supplementing Molybdenum, Molybdenum and Sulphur, and Zinc on Mineral Excretion of Sheep Fed with Palm Kernel Cake

Feeding high levels of palm kernel cake (PKC) has been reported to cause copper (Cu) toxicity in sheep. The degree of Cu toxicity is generally dependent on type of sheep breed, the form of Cu in the diets, feeding duration and interaction of Cu with other nutrients. This study was specifically camed out to investigate the effect of molybdenum (Mo), sulphur (S) and zinc (Zn) supplementation on the balance of minerals and to relate the findings with the degree of toxicity in Santa In& x Malin crossbred sheep. Twenty male Santa In& x Malin crossbred sheep from 8 months to 1 year of age were divided randomly into 4 groups. The animals were fed the following diets over the 6 months experimental period, PKC (86.2%); guinea grass hay (10%) supplemented with 30 ppm Mo (diet Mo), 20 ppm Mo +lo00 ppm S (diet Mo+S), . 500 ppm Zn (diet Zn) and the control without supplementation (diet Control). Faecal and urine samples were collected during the digestibility trial for mineral analysis. Mineral contents were also analyzed in blood plasma samples throughout the experiment period as well as from liver, kidney, pancreas and bile collected at slaughter. Mo+S or Mo alone and Zn treatments were observed to reduce the Cu level in the liver, kidney, pancreas and bile of the sheep. But Mo+S is more effective in reducing Cu from those tissues, especially the liver. Plasma minerals results showed that both Zn and Mo+S treatments were more effective in reducing Cu, Fe and Mg levels over time. Based on the results of this study, the hepatic Cu content was found to be higher in control group compared with other treatments. However, Mo+S treatment was found to be more effective in controlling and lowering Cu levels. There were significant effect of dietary supplement of Mo+S, Mo and Zn in increasing the loss of endogenous Cu from the body via faeces and urine

A Fast Vertical Edge Detection Algorithm for Car License Plate Detection

Recently, License Plate Detection (LPD) has been used in many applications especially in transportation systems. Many methods have been proposed in order to detect license plates, but most of them worked under restricted conditions, such as fixed illumination, stationary background, and high resolution images. LPD plays an important role in Car License Plate Recognition (CLPR) system because it affects the system's accuracy. This thesis aims to propose a fast vertical edge detector using Vertical Edge Detection Algorithm (VEDA) and to build a Car License Plate Detection (CLPD) method. Pre-processing step is performed in order to enhance and initialize the input image for the next steps. This step is divided into three processes: First, the color image conversion to a gray scale image. Second, an adaptive thresholding is used in order to constitute a binarized image. Third, Unwanted Lines Elimination Algorithm (ULEA) is used in order to enhance the image. The next step is to extract the vertical edges from the 352x288 resolution image by using VEDA. This algorithm is based on the contrast between the values in the binarized image. VEDA is proposed in order to enhance the CLPD method computation time. After the vertical edges have been extracted by VEDA, a morphological operation is used to highlight the vertical details in the image. Next, candidate regions are extracted. Finally, the license plate area is detected. This thesis shows that VEDA is faster than Sobel operator; the results reveal that VEDA is faster than Sobel by about 5-9 times, this range depends on the image resolution. The proposed CLPD method can efficiently detect the license plate area. The method shows the total time of processing one 352x288 image is 47.7 ms, and it meets the requirement of real time processing. Under the experiment datasets, which were taken from real scenes, 579 from 643 images are successfully detected. The average accuracy of car license plate detection is 90%. For more evaluation and comparison purposes, the proposed CLPD method is compared with a similar Malaysian license plate detection method, which is CAR Plate Extraction Technology (CARPET). This comparison reveled that the CLPD method is more efficient than CARPET and also has more detection rate