Earticle

A magnetic field generator for compression plasma discharge channel of micro EDM deposition has been designed. The self-magnetic field type by discharge current in the plasma channel of micro EDM deposition process has been analyzed. It presents a stable gradient annular magnetic field with the variables of discharge current and the distance from the discharge center. The force analysis of the charged particles in the discharge plasma channel under the self-magnetic field has been researched. The design principles of external magnetic field for enhancing the self-magnetic field to influence the machining performance have been put forward. Then, the structure type and dimension of external magnetic field generator have been determined. Results show that the external magnetic generator has the capability to enhance the self-magnetic field for compression plasma discharge channel with the proper structure parameters. With the increasing of the number of turns to 20, the external magnetic generator can influence the range of 0.10mm to 0.20mm from discharge channel center.

In order to resist external loads, multiple clamping forces will be produced to a workpiece so that its correct position can be immobilized during the entire machining operation. However, insufficient clamping forces cannot prevent the workpiece from motions whereas excessive clamping forces may cause the improper deformations of workpiece-fixture system. Therefore, a novel approach to clamping force determination is proposed for fixture design. Firstly, the measure method of magnitudes and placements of clamping forces is established from the various measure spaces to the uniform measure space for the first time. Secondly, a synchronous optimal model of magnitudes and placements of clamping forces is formulated as nonlinear constrained equations according to the minimum total complementary energy principle. By solving the resulting nonlinear equations, all contact forces including clamping forces and their application placements can accurately predicted in the frictional workpiece-fixture system. This method is illustrated with example cases. The method presented here may also have an application to other passive, indeterminate problems such as power grasps in robotics.

One of the most popular types of personal health device is the activity monitor, which is attached to the user’s wrist or waist in order to measure physical activity data such as exercise time/duration and calorie consumption. Given that it has an activity sensor and a gyro sensor to measure the speed of a user’s movement, an activity monitor can also be used to track the movement of sporting equipment. The accelerator sensor in the activity monitor used for this study can measure up to a certain level. When the activity monitor is attached to a body part or slow-moving sporting equipment, the limit of the certain level is considered to be enough to measure the activity data. However, the peak acceleration of fast-moving sporting equipment may exceed the certain level. In this paper, in order to overcome the limitations of the sensor, the peak acceleration of the fast-moving sporting equipment is estimated using the interpolation method based on the acceleration values of the rest of the movement. Furthermore, it also describes how to calculate a swing surface.

Quantum-dot cellular automata(QCA) provides a new approach in computer circuit design and development at nanotechnology level. This technology promises extraordinary high computing speeds, low heat dissipation and highly dense circuits. In this paper,two 2:4 decodersare proposed. The proposed structures reduce the clock phases to only three phases making them faster than the designs currently available in literature.The first proposed structure has reduced number of cells and hence covers a small area.The second proposed method although it has more cells, has regular clock zones that can facilitate the implementation of this circuit.Simulation of the circuits was done using QCADesigner.

In this paper, a high-speed video stream encoder for the H.264 digital video codec standard specification is accelerated with nowadays parallel processing architectures. Based on the parallel processing techniques with GPU's, we used an OpenCL-based GPU kernel programs, and finally achieved a high-level CPU-GPU interoperability. In its design, our system makes the CPU perform all input/output operations and overall stream control, while GPU does the core encoding operations. Our final result shows remarkable speed-up in comparison with the previous implementations. All the details of our implementation are presented in this paper.

This paper aims at developing a simple, efficient and cost effective maximum power point tracking(MPPT) system that can be employed for stand-alone Photovoltaic (PV) applications. The power versus voltage characteristics curves of PV system is non linear and variable with sun’s irradiation and temperature. To maximize the power utilization from a PV panel, a dynamic Perturb & Observe (P&O) MPPT algorithm is implemented using voltage and current sensors, a boost converter with digital signal controller (ds PIC4011).In any standalone PV system, the power conditioning unit receives energy from the PV source there by reducing the net power generation. Considering this, the sensor circuits and the components in power conditioning unit is so rationally selected that it is not only cost effective but also consumes very less power for its operation. The suggested technique is highly advantageous in the sense it is compatible photovoltaic system with and without battery banks. Prior to hardware implementation, the proposed system was validated using Matlab/Simulink environment. The simulation and hardware results reveal that the proposed MPPT system is more efficient when compared with existing systems.

Due to the proliferation of mobile devices such as smart phones and tablet computers, and increase in the speed of network devices to forward data, the Internet traffic has increased manyfold compare to a decade ago. Energy consumed by network devices handling the network traffic has increased manyfold also. Researchers are not only focusing on battery oriented network such as wireless sensor and ad hoc networks on saving battery power to extend network life but are also focusing on wired network to save energy consumed by network devices. Energy consumed by wired network can be reduced by putting underutilized network devices or links to sleep. If a network device has a few links such as a backbone network device, it is better to consider underutilized device to put to sleep, but if a network device has many links such as in data centers network devices and campus networks devices, it is better to consider underutilized links to put to sleep. In this paper, we consider putting underutilized links to sleep. Off course, if all links of a network device are put to sleep, the device itself will be put to sleep. Furthermore, in this paper we consider OpenFlow-based network as it is software defined network and flexible to control network devices. Besides, OpenFlow is being standardized by big enterprises such as NEC, Google, Cisco, Microsoft etc. We evaluated our approach by simulation and compare it with node based approach to see its effectiveness.

GUI-based software is often developed a complicated test script with existing traditional automation software testing tools. The software automated test development technology consequently carried out some study of existing automated testing with current automated testing tools to simplify the script. The paper proposed a novel test automation technology with separated definition data, which replaced by script development or modification. The definition data are depicted for script driven, page description and test data separately. The test automation technology provided completed function and interface between this method and actual test tool. The test engineers is not need to write the any test script, but modify the definition files for test developing to some extent. The automation functional test technology has support the typical test tool and proved effective in the specific cases.