WORKPIECE LOCATING AND POST PROCESSING SYSTEMS ON 6-DOF CNC MILLING MACHINE

A conventional non-computerized numerical control （CNC） machine is updated by mounting a six degree-of-free （DOF） parallel mechanism on it, thus obtaining a new CNC one. The structure of this CNC milling machine is introduced, and the workpiece locating system and the post processing system of the cutter location （CL） data file are analyzed. The new machine has advantages of low costs, simple structure, good rigidity, and high precision. It is easy to be transformed and used to process the workpiece with a complex surface.

PREPROCESSING AND POSTPROCESSING SYSTEM FOR FINITE ELEMENT COMPUTATION

This paper discusses some aspects of finite element computation,such as the automatic generation of finite element ,refinement of mesh,process of node density, distribution of load,optimum design and the drawing of stress contour, and describes the developing process of software for a planar 8 node element.

Prediction and Analysis of Post-Treatment of Sustainable Walnut Shell/Co-PES Parts by Laser Sintering

In order to enhance the strength of sustainable walnut shell/Co-PES(WSPC)sintered parts,wax-filtrated posttreatment was carried out.The effects of treating fluid temperature,preheating time and immersion time on the bending strength of WSPC wax-filtrated parts were analyzed by single factor analysis method.To obtain an accurate model for predicting the bending strength of the WSPC wax-filtrated part,the experiments were involved by using Box-Behnken design(BBD).Main parameters,such as treating fluid temperature,preheating time and immersion time,and their interactive effects were analyzed through analysis of variance(ANOVA)and graphical contours.The results demonstrated that all parameters’direct effects were significant to bending strength of the WSPC wax-filtrated part.Its optimum value was 5.0 MPa when the treating fluid temperature of 70°C,preheating time of 50 min,and immersion time of 20 s.The predicted models effectively validated had good predicting accuracy.The WSPC wax-filtrated part using optimal processing parameters was processed by investment casting,and then the metal casting of dimensional stability and smooth surface was obtained.Investment casting was done using WSPC wax-filtrated parts under optimal process parameters and then metal parts with stable structure size and smooth surface can be obtained,which indicates that WSPC material can be used for investment casting.

Interference Mitigation Techniques Using Receiver Processing and Resource Allocation

Heterogeneous network consists of the pico cells overlaid over the macro cell coverage area in a wireless cellular network. The pico cells are deployed to increase the capacity of the homogeneous network by reusing the spectrum further. However, more users will tend to be associated to the macro cell due to the fact that the transmit power of the pico cell is low. In order to increase the number of users associated to the pico cell, range extension techniques like biased association are used. This will cause severe interference to cell edge users of the pico cell from the macro cell causing degradation in throughput performance in the cell range extension area. In this paper, interference mitigation using receiver processing along with different scheduling techniques is proposed to improve the throughput, average delay, and the packet delivery ratio performance of the system. The performance comparison of the round robin, proportional fair and modified largest weighted delay first (MLWDF) algorithm for resource allocation using interference suppressing receiver is done, and analyzed. It is shown that the MLWDF algorithm achieves the highest throughput with minimum average delay of packets with the best delivery ratio.

Consequence of reinforced SiC particles and post process artificial ageing on microstructure and mechanical properties of friction stir processed AA7075

Friction stir processing and post process artificial ageing was successfully carried out on AA7075 with and without reinforcement of SiC particles producing defect free processed zone with uniform distribution of filler material.Effect of SiC particle reinforcement and artificial ageing times on the microstructural modifications was characterized using optical and electron microscopy,electron backscattered diffraction and X-Ray diffraction.Hardness,impact and wear tests were carried out to investigate mechanical behaviour before and after processing.Reinforcement of SiC particles during FSP and subsequent age hardening treatment brought about nearly twofold increase in hardness and impact toughness values by the combined effect of grain refinement,Zener pinning,dispersion strengthening and precipitation hardening.Significant improvement in wear resistance in terms of wear loss was also observed after processing compared to the reference material AA7075-T6.Fractured surface of post FSP age hardened AA7075 alloy exhibited features of ductile fracture during Charpy impact test.

Opportunities of Doubling Indian Farmers Income by Post Harvest Value Addition to Agricultural Produce

The governments across the developing countries are facing a challenge of steadily increasing population,maintaining balance in demand and supply of food and upliftment in socio-economic status of farming community.Among the leading developing countries,India has successfully increased agricultural crop production by fourfold,thus having at most potential for adoption of secondary agriculture practices after harvest of farm produce.Post-harvest processing of agricultural produce like milling of cereals and pulses,extraction of oil from oilseed crops,development of value added ready to eat and ready to serve food product etc.not only facilitate efficient utilization of crop produce but also check losses fetching better returns to the farmers/entrepreneurs.Post-harvest processing operations at the production catchment area helps in minimizing post harvest losses,helps in generating employment opportunities in rural areas,purity assured products in turn open window for the developed products to qualify for wider market.

A Full CMOS Integration Including ISFET Microsensors and Interface Circuit for Biochemical Applications

One of today's challenges is the integration of ISFETs in chemical and biochemical Microsystems.This article presents a full integration of ISFET chip containing the ISFET/REFET(reference FET) pair,ISFET/REFET amplifiers,bias current generator,as well as a reference electrode structure,all integrated on the same chip based on CMOS technology.The sensor chip was fabricated in a standard 0.35μm CMOS process(Chartered Semiconductor,Singapore).The extra post processing steps have been developed and added for depositing membranes.Finally,the pH response of the integrated sensor was measured with the interface circuit.

PROTOTYPE SURFACE MICRO- PRECISION IN FUSED DEPOSITION MODELING PROCESS

To aim at prototype parts fabricated with fused deposition modeling （FDM） process, the problems how to improve and enhance their surface micro-precision are studied. The producing mechanism of surface roughness is explained with three aspects concretely including the principle error of rapid prototyping （RP） process, the inherent characteristics of FDM process, and some mi- cro-scratches on the surface of the extruded fiber. Based on the micro-characters of section shape of the FDM prototype, a physical model reflecting the outer shape characters is abstracted. With the physical simplified and deduced, the evaluating equations of surface roughness are acquired. According to the FDM sample parts with special design for experimental measurement, the real surface roughness values of different inclined planes are obtained. And the measuring values of surface roughness are compared with the calculation values. Furthermore, the causes of surface roughness deviation between measuring values and calculation values are respectively analyzed and studied. With the references of analytic conclusions, the measuring values of the experimental part surface are revised, and the revised values nearly accord with the calculation values. Based on the influencing principles of FDM process parameters and special post processing of FDM prototype parts, some concrete measures are proposed to reduce the surface roughness of FDM parts, and the applying effects are better.

Automatic Extraction of Urban Road Centerlines from High-Resolution Satellite Imagery Using Automatic Thresholding and Morphological Operation Method

The commercial high-resolution imaging satellite with 1 m spatial resolution IKONOS is an important data source of information for urban planning and geographical information system (GIS) applications. In this paper, a morphological method is proposed. The proposed method combines the automatic thresholding and morphological operation techniques to extract the road centerline of the urban environment. This method intends to solve urban road centerline problems, vehicle, vegetation, building etc. Based on this morphological method, an object extractor is designed to extract road networks from highly remote sensing images. Some filters are applied in this experiment such as line reconstruction and region filling techniques to connect the disconnected road segments and remove the small redundant. Finally, the thinning algorithm is used to extract the road centerline. Experiments have been conducted on a high-resolution IKONOS and QuickBird images showing the efficiency of the proposed method.

The CAD/CAM Solution and Realization for Machining Large Scale Steel-concrete Objects

First the architecture of the integrated CAD/CAM system developed for machining large scale steel-concrete girders using I-DEAS and other developing tools are introduced; then the involved technologies in the development of the system are presented, which include the method for determining the position and orientation of the manufacturing features, the method for geometrical modeling of the girders, the techniques for generating the toolpaths for the 5-axis machining centers, the generative process planning technique and the postprocssing technique for the specific machines etc. Moreover some related special technical issues are also discussed. The CAD/CAM system is a network-based workshop-oriented manufacturing system, in which every machining cell can work independently serving two machining lines. The cell server take charge of the management of work schedules, personnel, machining resources, databases etc. the control computer serves to monitor the whole manufacturing lines, to arrange tasks, and to communicate; the two CAD/CAM workstations’ work is to model the girders using the CAD data, to plan the process and to generate the NC programs. The CL files that describe the toolpaths generated are ATP-format files. In order to translate them into NC codes that can be directly used by the 5-axis machining centers, a specific postprocessing program is developed for these distinct machines. The system has been successfully realized and applied in Shanghai Maglev Transrapid project. In the developing process, the following technical problems are solved: 1. Algorithms for measuring, positioning, and machining complex objects. 2. Methods for Modeling. 3. Animation and postprocess techniques for 5-axis machining centers. 4. Technologies for machining large-scale concrete-steel structures Although further evolution is needed for this system, the facts have proven its performance satisfactory and the technologies and the methods developed suitable.

A Robust Algorithm Based on Object Contours and Order Matching for Disparity Map Post-Processing

Based on the feature of stereo images' content and the property of natural objects, we redefine the general order matching constraint with object contour restriction. According to the modified order matching constraint, we propose a robust algorithm for disparity map post processing. Verified by computer simulations using synthetic stereo images with given disparities, our new algorithm proves to be not only efficient in disparity error detection and correction, but also very robust, which can resolve the severe problem in the algorithm proposed in Ref. that if there are large differences among the depths of objects in a scene, the algorithm will make mistakes during the process of disparity error detection and correction.

Advances in polishing of internal structures on parts made by laser-based powder bed fusion

The internal structures of metallic products are important in realizing functional applications.Considering the manufacturing of inner structures,laser-based powder bed fusion(L-PBF)is an attractive approach because its layering principle enables the fabrication of parts with customized interior structures.However,the inferior surface quality of L-PBF components hinders its productization progress seriously.In this article,process,basic forms,and applications relevant to L-PBF internal structures are reviewed comprehensively.The causes of poor surface quality and differences in the microstructure and property of the surface features of L-PBF inner structures are presented to provide a perspective of their surface characteristics.Various polishing technologies for L-PBF components with inner structures are presented,whereas their strengths and weaknesses are summarized along with a discussion on the challenges and prospects for improving the interior surface quality of L-PBF parts.

Porosity,cracks,and mechanical properties of additively manufactured tooling alloys:a review

Additive manufacturing(AM)technologies are currently employed for the manufacturing of completely functional parts and have gained the attention of hightechnology industries such as the aerospace,automotive,and biomedical fields.This is mainly due to their advantages in terms of low material waste and high productivity,particularly owing to the flexibility in the geometries that can be generated.In the tooling industry,specifically the manufacturing of dies and molds,AM technologies enable the generation of complex shapes,internal cooling channels,the repair of damaged dies and molds,and an improved performance of dies and molds employing multipleAMmaterials.Inthepresentpaper,a reviewof AM processes and materials applied in the tooling industry for the generation of dies and molds is addressed.AM technologies used for tooling applications and the characteristics of the materials employed in this industry are first presented.In addition,the most relevant state-of-the-art approaches are analyzed with respect to the process parameters and microstructural and mechanical properties in the processing of high-performance tooling materials used in AM processes.Concretely,studies on the AM of ferrous(maraging steels and H13 steel alloy)and non-ferrous(stellite alloys and WC alloys)tooling alloys are also analyzed.

Study of frame-rate up conversion based on H.264

In this study, a low complexity frame-rate up conversion method using compressed domain information for H.264 decoder is proposed. In the proposed scheme, the motion vectors （MVs） are estimated using constant acceleration motion model, and the MVs regarded as no credibility are corrected, and the interpolation method is applied on the basis of the macroblock （MB） coded types. Applied to the H.264 decoder, the proposed method provides high quality interpolation frames and an obvious decrease of the block artifacts.

Polynomial-based smooth trajectory planning for fruit-picking robot manipulator

Fruit-picking robot is an important form of intelligent agricultural machinery and has great impact in smart agriculture.Motion planning for its multi-Degree of Freedoms(DOFs)manipulator is significant to picking efficiency and fruit quality.However,it is difficult to plan appropriate trajectory for such a complex system.The purpose of this article is to gen-erate smooth trajectories for fruit-picking robot manipulators using shortcuts that are con-strained in velocity,acceleration and jerk.The proposed algorithm smooths the robot motion as a post process to trajectory planning.Given an input jerky path,the algorithm will first convert it into a fully synchronized trajectory,and then attempt to reduce the exe-cution time of this trajectory as much as possible while retaining the kinematic motion constraints.The idea of the proposed method is to build shorter and collision-free short-cuts that replace the intermediate motion between two randomly-picked points on the tra-jectory.Experiments carried on a mobile fruit-picking robot demonstrate that this technique is able to generate smooth and collision-free trajectories for robot manipulators.

AntarcticaLC2000：The new Antarctic land cover database for the year 2000

Antarctica plays a key role in global energy balance and sea level change.It has been conventionally viewed as a whole ice body with high albedo in General Circulation Models or Regional Climate Models and the differences of land cover has usually been overlooked.Land cover in Antarctica is one of the most important drivers of changes in the Earth system.Detailed land cover information over the Antarctic region is necessary as spatial resolution improves in land process models.However,there is a lack of complete Antarctic land cover dataset derived from a consistent data source.To fill this data gap,we have produced a database named Antarctic Land Cover Database for the Year 2000(AntarcticaLC2000) using Landsat Enhanced Thematic Mapper Plus(ETM+) data acquired around 2000 and Moderate Resolution Imaging Spectrometer(MODIS) images acquired in the austral summer of 2003/2004 according to the criteria for the 1:100000-scale.Three land cover types were included in this map,separately,ice-free rocks,blue ice,and snow/firn.This classification legend was determined based on a review of the land cover systems in Antarctica(LCCSA) and an analysis of different land surface types and the potential of satellite data.Image classification was conducted through a combined usage of computer-aided and manual interpretation methods.A total of 4067 validation sample units were collected through visual interpretation in a stratified random sampling manner.An overall accuracy of 92.3%and the Kappa coefficient of 0.836 were achieved.Results show that the areas and percentages of ice-free rocks,blue ice,and snow/firn are 73268.81 km2(0.537%),225937.26 km2(1.656%),and 13345460.41 km2(97.807%),respectively.The comparisons with other different data proved a higher accuracy of our product and a more advantageous data quality.These indicate that AntarcticaLC2000,the new land cover dataset for Antarctica entirely derived from satellite data,is a reliable product for a broad spectrum of applications.