Advanced Materials Research Vols. 403-408

Abstract: This paper principally examines the flow pattern that occurs when molten weld metal droplets are detached from globule formations at the tip of an electrode and are thereafter transported to the weldpool. This viscoplastic flow study was done using the modified Casson prediction model which is based on the Newtonian Homogenous Flow equations. Both chemical and mechanical tests were done. The inclusions (Slag) were found to possess an upward flow of 3 ms-1. The mechanical test results show that the shear stress of 483.2 MPa, which exceeded a yield stress of 230 MPa, was responsible for the continuous slipping movement of the molten metal towards the center of the weld pool at a velocity of 1.2ms-1. The results obtained by the application of this model were validated by both computational and experimental results obtained by other researchers.

Abstract: With the combination of theoretical analysis, numerical simulation and actual test, the factors and rules impacting the collapse strength are studied. The collapse strength of the casing wear presents changes of exponent, power function, and linear trend with the residual casing wall thickness, wear radius and axial load respectively. Based on this, the computation model of collapsing strength for the whole casing wear has been established and the model is tested for verification by computing collapse strength of non-casing wear. The study results provide a guide for design of the casing sting strength and down-hole safety.

Abstract: The emergence of Application-specific Instruction-set Processor (ASIP) has encouraged the proliferation of tool-chains used to streamline its design flow. One of the features much sought-after in these tool-chains is notably the automatic generation of Application-specific Functional Units (AFUs) which, in turn, involves the custom instruction generation as a crucial step. Whereupon an additional step is assumed to pipeline the patterns identified for fulfilling the I/O constraint, custom instructions that correspond to maximal valid subgraphs are mostly beneficial to the speedup gain. Therefore, we present in this paper a propositional satisfiability approach to efficiently identify the custom instructions which contain a large number of valid nodes. Our approach is different substantially from the previous works where it uses an edge classification method to reduce the search space for convexity checking. The experiment results show that our method can, in a matter of few seconds, identify a set of custom instructions that speed up the application to a few times faster.

Abstract: This paper proposes a mobile phone based security and control system for home appliances through SMS/Bluetooth. It focuses on controlling home appliances remotely, and providing security with good graphical user interface. The system uses GSM technology, providing ubiquitous access to the system for security and automated appliance control from anywhere around the globe. The system provides security against intrusion using a smarter digital lock which notifies owners in case of an unauthorized via SMS message, as well as facilitates both short and long-range device control using Bluetooth or SMS technology. Rather than a conventional method of sending an SMS message to control devices, a graphical user interface is designed using Python S60 language for ease of use. The control signals in the form of SMS messages are encrypted and restricted to unique mobile phones or SIM cards for improved security.

Abstract: In any remote surveillance scenario, smart cameras have to take intelligent decisions to generate summary frames to minimize communication and processing overhead. Video summary generation, in the context of smart camera, is the process of merging the information from multiple frames. A summary generation scheme based on clustering based change detection algorithm has been implemented in our smart camera system for generating frames to deliver requisite information. In this paper we propose an embedded platform based framework for implementing summary generation scheme using HW-SW Co-Design based methodology. The complete system is implemented on Xilinx XUP Virtex-II Pro FPGA board. The overall algorithm is running on PowerPC405 and some of the blocks which are computationally intensive and more frequently called are implemented in hardware using VHDL. The system is designed using Xilinx Embedded Design Kit (EDK).

Abstract: The performance of the current and the next generation server applications such as E-Commerce, Storage and Web server that employ TCP/IP and UDP/IP as the communication protocol of choice depends upon the efficiency of the Protocol Stack Processing within this node. As the speed of networks exceeds one GBPS, the design and implementation of high-performance Network Interfaces (NI) for servers become very challenging. It is observed that using programmable NI with a general purpose processing core to offload some of the TCP/IP or UDP/IP protocol functions can deliver some important features which include scalability, short development times and reduced costs. In this paper, we proposes a new NI-programmable based model that support the Large Segment Offload (LSO) for sending side and a novel technique called Receiving Side Amalgamating (RSA) for receiving side and which is used for incoming packets. The core engine assigned to handle these functions is single specialized embedded processors utilizing RISC cores in each side. As a result, a 240 MHz RISC core can be used in Ethernet Network Interface ENI card for wide range of transmission line speed up to 100 Gbps. These results are based on the use of a specialized RISC core that we developed and simulated. Also, the author has discussed some of the design issues that are related to RISC core based NI and the data movement type.

Abstract: The wheel hub PCD (Pitch Circle Diameter) is the diameter of the circle whose circumference connects the centers of all bolt holes in the hub. Common bolt patterns are four, five and six-hole patterns, etc, and the product of the number of holes and PCD is an important parameter of wheel hubs. This article discusses the digital-image-processing-aided precise measurement of geometric data of hole-distributions, such as bolt-hole-center coordinates x0 and y0, pitch circle diameter PCD, angle between adjacent bolt holes θ, axle-hole-center coordinates and the radius from each bolt hole to the center of the axle hole, etc.

Abstract: A method of robust and positive realness control for continuous descriptor systems with time-delay and uncertainties has been given in the paper. By some parameters, the controller can make the closed-loop systems realize quadratic stability and robust positive realness. The efficiency of the method can be illustrated by a numerical example.

Abstract: In this paper, the virtual temporal sensors is introduced to function as those physical sensors, and a new approach for array calibration using temporal information is proposed, which possess a high accuracy while its computation burden is low. Theory analysis and simulation results are presented to demonstrate the performance of the proposed method.

Abstract: Frequency agility radar has strong ECCM capability. This paper studies the major technology for jamming FAR, and detailed analyses the influence to radar performance of frequency agility. It is significant for supplying reasoning information to the alteration of former arming and developing of new one.