998 research outputs found
HP4 High-Performance Programmable Packet Parser
Now, header parsing is the main topic in the modern network systems to support many operations such as packet processing and security functions. The header parser design has a significant effect on the network devices' performances (latency, throughput, and resource utilization). However, the header parser design suffers from a lot number of difficulties, such as the incrementing in network throughput and a variety of protocols. Therefore, the programmable hardware packet parsing is the best solution to meet the dynamic reconfiguration and speed needs. Field Programmable Gate Array (FPGA) is an appropriate device for programmable high-speed packet implementation. This paper introduces a novel FPGA High-Performance Programmable Packet Parser architecture (HP4). HP4 automatically generated by the P4 (Programming protocol-independent Packet Processors) to optimize the speed, dynamic reconfiguration, and resource consumption. The HP4 shows a pipelined packet parser dynamic reconfiguration and low latency. In addition to high throughput (over 600 Gb/s), HP4 resource utilization is less than 7.5 percent of Virtex-7 870HT, and latency is about 88 ns. HP4 can use in a high-speed dynamic packet switch and network security
Common conditions of construction contracts in Egypt
Construction is known to be one of the riskiest industries as it can be affected by many foreseeable and unforeseeable circumstances and events leading to turning a project from a profitable status to incurring losses and vice versa. Such circumstances and events can include economic crisis, political decisions, wars, unforeseen ground conditions, unassigned responsibilities, flawed designs and many others. A well drafted construction contract reduces the effects of such uncertainties to a great extent by addressing as many potential risks as possible. In order to achieve such an aim, various international institutions have formulated international contract standards, which are used as general conditions to construction contracts in different areas in the world. Such conditions are complemented with particular conditions by contracts’ practitioners who would consider the specific natures of their projects as well as the countries and relevant laws of the destinations of the construction projects in hand. Despite the fact that the aim of particular conditions is to address the specific nature and circumstances of construction projects, the result can be otherwise or not as effective as expected. A major reason is the insufficient experience of a contract drafter which may not be inclusive to account for all scenarios and risks that may take place. This research aims at investigating the major risks facing construction projects as reflected through the particular conditions of a number of construction contracts, and presenting the top common conditions that are deemed to be of high importance for the consideration of contracts’ practitioners during the contract drafting process. While the research contributes in drafting particular conditions, it is not the objective of this research to create an ideal form of particular conditions. However, the main objective is to highlight the top particular conditions that have been already identified in construction contracts, literature review and experts’ opinions. Reaching such an objective would assist contract drafters in preparing adequate contract conditions and hence reducing the probability of disputes between projects’ parties if the herein findings are considered. The research mainly focuses on the analysis of the particular conditions of 28 construction contracts in order to understand the common considerations and risks. The outcome includes the top 30 common particular condition clauses that are recommended to be addressed within the particular conditions of new construction contracts, with details as to the specific provisions that are of significance under each clause. It should be noted that each of the top 30 conditions was included/addressed by more than 50% of the analyzed contracts. The methodology of the research mainly incorporates undertaking a literature review, executing a comparison and analysis of particular conditions, verifying analysis’ findings through experts’ surveys and presenting the findings. The findings of this research shows that 102 provisions relevant to 30 particular clauses are of significant importance to be considered while drafting new construction contracts
An indexing method for answering queries on moving objects
We consider the problem of indexing a set of objects moving in d-dimensional spaces along linear trajectories. A simple external-memory indexing scheme is proposed to efficiently answer general range queries. The following are examples of the queries that can be answered by the proposed method: report all moving objects that will (i) pass between two given points within a specified time interval; (ii) become within a given distance from some or all of a given set of other moving objects. Our scheme is based on mapping the objects to a dual space, where queries about moving objects are transformed into polyhedral queries concerning their speeds and initial locations. We then present a simple method for answering such polyhedral queries, based on partitioning the space into disjoint regions and using a B+-tree to index the points in each region. By appropriately selecting the boundaries of each region, we guarantee an average search time that matches a known lower bound for the problem. Specifically, for a fixed d, if the coordinates of a given set of N points are statistically independent, the proposed technique answers polyhedral queries, on the average, in O((N/B)1-1/d ·(log B N)1/d +K/B) I/O\u27s using O(N/B) space, where B is the block size, and K is the number of reported points. Our approach is novel in that, while it provides a theoretical upper bound on the average query time, it avoids the use of complicated data structures, making it an effective candidate for practical applications. The proposed index is also dynamic in the sense that it allows object insertion and deletion in an amortized update cost of log B (N) I/O\u27s. Experimental results are presented to show the superiority of the proposed index over other methods based on R-trees. © 2005 Springer Science + Business Media, Inc
Improved feature selection using a hybrid side-blotched lizard algorithm and genetic algorithm approach
Feature selection entails choosing the significant features among a wide collection of original features that are essential for predicting test data using a classifier. Feature selection is commonly used in various applications, such as bioinformatics, data mining, and the analysis of written texts, where the dataset contains tens or hundreds of thousands of features, making it difficult to analyze such a large feature set. Removing irrelevant features improves the predictor performance, making it more accurate and cost-effective. In this research, a novel hybrid technique is presented for feature selection that aims to enhance classification accuracy. A hybrid binary version of side-blotched lizard algorithm (SBLA) with genetic algorithm (GA), namely SBLAGA, which combines the strengths of both algorithms is proposed. We use a sigmoid function to adapt the continuous variables values into a binary one, and evaluate our proposed algorithm on twenty-three standard benchmark datasets. Average classification accuracy, average number of selected features and average fitness value were the evaluation criteria. According to the experimental results, SBLAGA demonstrated superior performance compared to SBLA and GA with regards to these criteria. We further compare SBLAGA with four wrapper feature selection methods that are widely used in the literature, and find it to be more efficient
An indexing method for answering queries on moving objects
We consider the problem of indexing a set of objects moving in d-dimensional spaces along linear trajectories. A simple external-memory indexing scheme is proposed to efficiently answer general range queries. The following are examples of the queries that can be answered by the proposed method: report all moving objects that will (i) pass between two given points within a specified time interval; (ii) become within a given distance from some or all of a given set of other moving objects. Our scheme is based on mapping the objects to a dual space, where queries about moving objects are transformed into polyhedral queries concerning their speeds and initial locations. We then present a simple method for answering such polyhedral queries, based on partitioning the space into disjoint regions and using a B+-tree to index the points in each region. By appropriately selecting the boundaries of each region, we guarantee an average search time that matches a known lower bound for the problem. Specifically, for a fixed d, if the coordinates of a given set of N points are statistically independent, the proposed technique answers polyhedral queries, on the average, in O((N/B)1-1/d ·(log B N)1/d +K/B) I/O\u27s using O(N/B) space, where B is the block size, and K is the number of reported points. Our approach is novel in that, while it provides a theoretical upper bound on the average query time, it avoids the use of complicated data structures, making it an effective candidate for practical applications. The proposed index is also dynamic in the sense that it allows object insertion and deletion in an amortized update cost of log B (N) I/O\u27s. Experimental results are presented to show the superiority of the proposed index over other methods based on R-trees. © 2005 Springer Science + Business Media, Inc
Remotely interrogated MEMS pressure sensor
This thesis considers the design and implementation of passive wireless microwave readable pressure sensors on a single chip. Two novel-all passive devices are considered for wireless pressure operation.
The first device consists of a tuned circuit operating at 10 GHz fabricated on SiO2 membrane, supported on a silicon wafer. A pressure difference across the membrane causes it to deflect so that a passive resonant circuit detunes. The circuit is remotely interrogated to read off the sensor data. The chip area is 20 mm2 and the membrane area is 2mm2 with thickness of 4 µm. Two on chip passive resonant circuits were investigated: a meandered dipole and a zigzag antenna. Both have a physical length of 4.25 mm. the sensors show a shift in their resonant frequency in response to changing pressure of 10.28-10.27 GHz for the meandered dipole, and 9.61-9.58 GHz for the zigzag antenna. The sensitivities of the meandered dipole and zigzag sensors are 12.5 kHz and 16 kHz mbar, respectively.
The second device is a pressure sensor on CMOS chip. The sensing element is capacitor array covering an area of 2 mm2 on a membrane. This sensor is coupled with a dipole antenna operating at 8.77 GHz. The post processing of the CMOS chip is carried out only in three steps, and the sensor on its own shows a sensitivity of 0.47fF/mbar and wireless sensitivity of 27 kHz/mbar. The MIM capacitors on membrane can be used to detune the resonant frequency of an antenna
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