A complex software environment such as the ALICE Computing Grid infrastructure requires permanent control and management for the large set of services involved. Automating control procedures reduces ...the human interaction with the various components of the system and yields better availability of the overall system. In this paper we will present how we used the MonALISA framework to gather, store and display the relevant metrics in the entire system from central and remote site services. We will also show the automatic local and global procedures that are triggered by the monitored values. Decision-taking agents are used to restart remote services, alert the operators in case of problems that cannot be automatically solved, submit production jobs, replicate and analyze raw data, resource load-balance and other control mechanisms that optimize the overall work flow and simplify day-to-day operations. Synthetic graphical views for all operational parameters, correlations, state of services and applications as well as the full history of all monitoring metrics are available for the ent ire system that now encompasses 85 sites all over the world, mo re than 14000 CPU cores and 10PB of storage.
This study was conducted in order to determine the material hardness value due to modification of the milling cutting parameters. The alloy hardness was analysed as a function of different cutting ...parameters for milling operations (speed, feed and depth of cut), using a face mill. A total number of 17 samples were machined using parameters obtained by combining the input parameters. The total number of combinations is reduced by a preoptimization, using the DesignExpert software. The cutting process was performed in dry conditions, and it was recorded that dry cutting magnesium-aluminium alloy AZ61A with the used parameters did not lead to chip ignition. The surface hardness was determined based on the Vickers scale (HV), its values ranging from 110.59 HV to 121.37 HV. The obtained results showed that the feed has a significant contribution in the surface harness modification. The application of the Taguchi method reveals that the material hardness can be improved, together with the manufacturing time, by means of the speed, feed and depth of cut maximization.
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High-Energy Physics experiments like ALICE at LHC require petabytes of storage and thousand of CPU working in parallel to store, reconstruct and analyze the collected data. This computing power is ...provided by aggregating the resources of hundreds of institutes and research centers and in addition several purpose-built large computing centers. All these resources are transparently available to the users under the umbrella of ALICE Grid. To ensure smooth operation of this complex distributed machinery we have developed a set of tools to monitor and control the various services, based on the MonALISA monitoring framework. By integrating monitoring information in the system we have achieved a high degree of automation and have significantly reduced the burden on the Grid managers. In this article we present how we collect the monitoring information and a few of the tools that make use of it.
Recent developments in the field of bio-engineering allow the use of magnesium alloys as a substitute for medical implants. The issue with such alloys is the degradation rate witch has to be improved ...in order to provide the necessary support for the entire duration of the bone fraction healing. For improving the bone shielding heat treatment does not represent a solution, but chemical and or mechanical do. One mechanical process that has excellent result is burnishing, but this process is difficult to be implemented on a milling machine. Therefore, it was necessary that a new tool and tool holder to be developed, that allow the simultaneous process to take place. A high-pressure hydraulic roller burnishing tool with a special tool holder was used on a CNC milling machine. The material used for this study is magnesium alloy AZ31B-F, and one of the main purposes was to improve the material hardness (HV). The milling-burnishing parameters that where varied are the speed and feed, burnishing pressure and depth, type of process (successive or simultaneous), machining direction and the material hardness after milling. The results were analyzed as percentage improvement between the milling and burnishing measured values.
A new synthetic concept named TERMINI that stands for irreversible TERminator Multifunctional INItiator is reported. Suitable combinations of TERMINI and living polymerizations provide access to ...strategies for the design and synthesis of unprecedented complex molecular and macromolecular architectures from a diversity of commercial monomers. TERMINI represents a masked multifunctional initiator designed to quantitatively and irreversibly interrupt a chain organic reaction or a living polymerization. After demasking, the TERMINI repeat unit enables the quantitative reinitiation, in the presence or absence of a catalyst, of the same or a different living polymerization or a chain organic reaction in more than one direction, thus becoming a branching point. The demonstration of this concept was made by using a combination of metal-catalyzed living radical polymerization (LRP) and (1,1-dimethylethyl)1-3,5-bis(S-phenyl 4-N,N ‘ -diethylthiocarbamate)phenylethenyloxydimethylsilane as TERMINI, to elaborate a novel iterative divergent method for the synthesis of dendritic macromolecules based on methyl methacrylate (MMA).
We introduce a novel third order analogue nonlinear system, using three multipliers as nonlinear functions. The proposed system exhibits rich nonlinear dynamics, with periodic and chaotic behaviors, ...depending on the system parameters. The strange attractor of the system, under chaotic parameter choice, is characterized by a limited domain occupied in the state space. The analysis of the nonlinear dynamics of the system is presented and in depth simulation results confirm the desired properties. Suggested applications of the proposed system include analogue noise generators and spread spectrum clock generators. Index Terms--chaos, noise generators, nonlinear attractors, nonlinear dynamical systems, pulse generation.
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