ZERO TRANSMISSION AND ITS APPLICATION IN HIGH SPEED CNC MACHINE TOOLS

In order to realize high speed machining,the special requirements for the transmission and sturctrue of CNC machine tool have to be satisfied.A high speed spindle unit driven by a built-in motor is developed.An oil-water heat exchange system is used for cooling the spindle motor.The spindle is supported by Si_4N_3 ceramic ball angular contact bearings. An oil-air lubricator is used to lubricate and cool the spindle bearings.Some special structures are taken for balancing the spindle.

MICRO ELECTRICAL DISCHARGE MACHINING DEPOSITION IN AIR

A new deposition method is described using micro electrical discharge machining （EDM） to deposit tool electrode material on workpiece in air. The basic principles of micro electrical discharge deposition （EDD） are analyzed and the realized conditions are predicted. With an ordinary EDM shaping machine, brass as the electrode, high-speed steel as the workpiece, a lot of experiments are carried out on micro EDD systematically and thoroughly. The effects of major processing parameters, such as the discharge current, discharge duration, pulse interval and working medium, are obtained, As a result, a micro cylinder with 0.19 mm in diameter and 7.35 mm in height is deposited. By exchanging the polarities of the electrode and workpiece the micro cylinder can be removed selectively. So the reversible machining of deposition and removal is achieved, which breaks through the constraint of traditional EDM. Measurements show that the deposited material is compact and close to workpiece base, whose components depend on the tool electrode, material.

Energy-Efficient Framework for Virtual Machine Consolidation in Cloud Data Centers

With the advent of the era of cloud computing, the high energy consumption of cloud computing data centers has become a prominent problem, and how to reduce the energy consumption of cloud computing data center and improve the efficiency of data center has become the research focus of researchers all the world. In a cloud environment, virtual machine consolidation(VMC) is an effective strategy that can improve the energy efficiency. However, at the same time, in the process of virtual machine consolidation, we need to deal with the tradeoff between energy consumption and excellent service performance to meet service level agreement(SLA). In this paper, we propose a new virtual machine consolidation framework for achieving better energy efficiency-Improved Underloaded Decision(IUD) algorithm and Minimum Average Utilization Difference(MAUD) algorithm. Finally, based on real workload data on Planet Lab, experiments have been done with the cloud simulation platform Cloud Sim. The experimental result shows that the proposed algorithm can reduce the energy consumption and SLA violation of data centers compared with existing algorithms, improving the energy efficiency of data centers.

WEB-BASED VIRTUAL CNC MACHINE MODELING AND OPERATION

A CNC simulation system based on intemet for operation training of manufacturing facility and manufacturing process simulation is proposed. Firstly, the system framework and a rapid modeling method of CNC machine tool are studied under the virtual environment based on PolyTrans and CAD software. Then, a new method is proposed to enhance and expand the interactive ability of virtual reality modeling language（VRML） by attaining communication among VRML, JavaApplet, JavaScript and Html so as to realize the virtual operation for CNC machine tool. Moreover, the algorithm of material removed simulation based on VRML Z-map is presented. The advantages of this algorithm include less memory requirement and much higher computation. Lastly, the CNC milling machine is taken as an illustrative example for the prototype development in order to validate the feasibility of the proposed approach.

Fortifying the Digital Bastion: Pioneering Cybersecurity with Dynamic Secrets Management and CMDB Fusion in the Enterprise

In the relentless quest for digital sovereignty, organizations face an unprecedented challenge in safeguarding sensitive information, protecting against cyber threats, and maintaining regulatory compliance. This manuscript unveils a revolutionary blueprint for cyber resilience, empowering organizations to transcend the limitations of traditional cybersecurity paradigms and forge ahead into uncharted territories of data security excellence and frictionless secrets management experience. Enter a new era of cybersecurity innovation and continued excellence. By seamlessly integrating secrets based on logical environments and applications (assets), dynamic secrets management orchestrates and automates the secrets lifecycle management with other platform cohesive integrations. Enterprises can enhance security, streamline operations, fasten development practices, avoid secrets sprawl, and improve overall compliance and DevSecOps practice. This enables the enterprises to enhance security, streamline operations, fasten development & deployment practices, avoid secrets spawls, and improve overall volume in shipping software with paved-road DevSecOps Practices, and improve developers’ productivity. By seamlessly integrating secrets based on logical environments and applications (assets), dynamic secrets management orchestrates and automates the application secrets lifecycle with other platform cohesive integrations. Organizations can enhance security, streamline operations, fasten development & deployment practices, avoid secrets sprawl, and improve overall volume in shipping software with paved-road DevSecOps practices. Most importantly, increases developer productivity.

New Method for Studying Rock-Breaking Mechanism by Disc Cutters

Gaining a thorough understanding of the theoretical principles of rock breaking with a disc cutter is a critical issue in tunnel boring machine (TBM) technology. To fully consider the complexity and importance of the basic principles of rock breaking during tunnel excavation, in this paper we use a new method, the smooth particle hydrodynamics (SPH), to study the rock-breaking mechanism and verify its accuracy and feasibility. Using the SPH method, we induce the rock fragmentation process with two cutters in synchronous and sequential orders. The results show that when the cutters act on rock sequentially, the second indentation influences the crack evolution of the first indentation. With increased cutter spacing, the second crack gradually becomes independent of the first crack. Under synchronous action of the two cutters, a bursiform nucleus is generated beneath the cutters and the area of the nucleus increases with increased cutter spacing. Whether the cutters act on the rock sequentially or synchronously, we found the optimum cutter spacing of our chosen rock type to be 60 mm. Our analyses results show that the efficiency of sequential rock cutting is superior to synchronous cutting, both with respect to crack evolution and cutter force. © 2017, Tianjin University and Springer-Verlag Berlin Heidelberg.

Improving the Patient Discharge Planning Process through Knowledge Management by Using the Internet of Things

The UK National Health Service (NHS) is faced with problems of managing patient discharge and preventing the problems that result from it such as frequent readmissions, delayed discharge, long waiting lists, bed blocking and other such consequences. The problem is exacerbated by the growth in size, complexity and the number of chronic diseases in the NHS. In addition, there is an increase in demand for high quality care, processes and planning. Effective Discharge Planning (DP) requires practitioners to have appropriate, patient personalised and updated knowledge in order to be able to make informed and holistic decisions about a patients’ discharge. This paper examines the role of Knowledge Management (KM) in both sharing knowledge and using tacit knowledge to create appropriate patient discharge pathways. The paper details the factors resulting in inadequate DP, and demonstrates the use of Internet of Things (IoT) and Machine2Machine (M2M) as candidate technologies and possible solutions which can help reduce the problem. The use of devices that a patient can take home and devices which are perused in the hospital generate information, which can serve useful when presented to the right person at the right time, thus harvesting knowledge. The knowledge when fed back can support practitioners in making holistic decisions with regards to a patients’ discharge.

RISE: A RelIable and SEcure Scheme for Wireless Machine to Machine Communications

Wireless Machine to Machine （M2M） communications enable ubiquitous sensing, controlling, and acting via sensors, actuators, and actors. Reliability and security are of foremost importance in wireless M2M systems. A simple, target distinguishing attack can result in M2M＇s failure. This paper presents a Reliable and SEcure scheme, RISE, which is a package of policies that guarantee the reliability of data （including sensor reports and actuator instructions） and devices （including sensors, actuators, and actors）. The data reliability is improved by four algorithms, ChooseMedian, ChooseMost, ChooseNearest, and Trust-based Enhancement. Report attainability is improved via m repeat-sending and n multiple-reporting algorithms. Device reliability is guaranteed by device-indistinguishability, which comprises data-indistinguishability and behavior-indistinguishability. The security requirements are formally defined, and the security analysis proves the soundness and completeness of the scheme,

Research on the nanometric machining of a single crystal nickel via molecular dynamics simulation

Molecular dynamics simulations are employed to study the nanometric machining process of single crystal nickel. Atoms from different machining zones had different atomic crystal structures owing to the differences in the actions of the cutting tool. The stacking fault tetrahedral was formed by a series of dislocation reactions, and it maintained the stable structure after the dislocation reactions. In addition, evidence of crystal transition and recovery was found by analyzing the number variations in different types of atoms in the primary shear zone, amorphous region, and crystalline region. The effects of machining speed on the cutting force, chip and subsurface defects, and temperature of the contact zone between the tool and workpiece were investigated. The results suggest that higher the machining speed, larger is the cutting force. The degree of amorphousness of chip atoms and the depth and extent of subsurface defects increase with the machining speed. The average friction coefficient first decreases and then increases with the machining speed because of the temperature difference between the chip and machining surface.

Electrical Discharge Machining of Al2024-65 vol%SiC Composites

In the present work, the wire electrical discharge machining（WEDM） process of the 65 vol% SiCp/2024 Al composite prepared by pressure infiltration methods has been investigated. The microstructure of the machined composite was characterized by scanning electron microscope, the average surface roughness（Ra）, X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy（TEM） techniques. Three zones from the surface to the interior（melting zone, heat affected zone and un-affected zone） were found in the machined composites, while the face of SiC particles on the surface toward the outside was ‘‘cut＇＇ to be flat. Increase in Al and Si but decrease in C and O were observed in the core areas of the removed particles. Si phase, which was generated due to the decomposition of SiC, was detected after the WEDM process. The irregular and spherical particles were further observed by TEM. Based on the microstructure observation, it is suggested that the machining mechanism of 65 vol% SiCp/2024 Al composite was the combination of the melting of Al matrix and the decomposition of SiC particles.

Investigation on surface structuring generated by electrochemical micromachining

Surface geometrical features and their function- ality depend on the manufacturing process which is employed for fabrication of surface structures. Maskless electrochemical micromachining （EMM） is used to generate various surface structures for diminishing and controlling friction and wear to increase the lifetime, reliability, and efficiency of mechanical systems. This paper presents a method for the generation of structured surfaces on stainless steel （SS-304） surfaces by using maskless EMM. The micropatterned tool is composed of 800 μm diameter circular holes in a 5 × 5 matrix form. The indigenously developed EMM set up consists of an EMM cell, electrical power supply system, and a controlled vertical cross-flow electrolyte circulation arrangement to control the influence of process parameters during the generation of the micro features of structured surfaces. The single structured cathode tool is used for the mass production of structured surfaces with a short fabrication time in the industrial context by avoiding the use of an individual masking process for each workpiece. The process has been characterized in terms of the effects of predominant process parameters such as machining voltage, electrolyte concentration, duty ratio, pulsed frequency, and machining time on the machined surface characteristics such as current efficiency, machining accuracy, and depth of the circular pattern on the stainless steel surfaces. A mathematical model is also developed to determine the theoretical depth of the dimple pattern and correlate the theoretical depths with actual depths as obtained by experimentation. Moreover, an effort has been made to study the structuringcharacteristics on the basis of micrographs obtained duringthe EMM.

Generating Conformance Tests for Nondeterministic Protocol Machines

We present a method of generating test cases from the software specifications which are modeled by nondeterministic finite state machines. It is applicable to both nondeterministic and deterministic finite state machines. When applied to deterministic machines, this method yields usually smaller test suites with full fault coverage than the existing methods that also assure full fault coverage. In particular, the proposed mehod can be used to test the control portion of software specified in the formalspecification languages SDL or ESTELLE.

Patterns of Chromatin-Modifications Discriminate Different Genomic Features in Arabidopsis

Dynamic regulation and packaging of genetic information is achieved by the organization of DNA into chromatin. Nucleosomal core histones, which form the basic repeating unit of chromatin, are subject to various post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitinylation. These modifications have effects on chromatin structure and, along with DNA methylation, regulate gene transcription.The goal of this study was to determine if patterns in modifications were related to different categories of genomic features, and, if so, if the patterns had predictive value. In this study, we used publically available data（ChIP-chip）for different types of histone modifications（methylation and acetylation） and for DNA methylation for Arabidopsis thaliana and then applied a machine learning based approach（a support vector machine） to demonstrate that patterns of these modifications are very different among different kinds of genomic feature categories（protein, RNA,pseudogene, and transposon elements）. These patterns can be used to distinguish the types of genomic features.DNA methylation and H3K4me3 methylation emerged as features with most discriminative power. From our analysis on Arabidopsis, we were able to predict 33 novel genomic features, whose existence was also supported by analysis of RNA-seq experiments. In summary, we present a novel approach which can be used to discriminate/detect different categories of genomic features based upon their patterns of chromatin modification and DNA methylation.