On the origin of intrinsic randomness of Rayleigh-B′enard turbulence

It is of broad interest to understand how the evolution of non-equilibrium systems can be triggered and the role played by external perturbations. A famous example is the origin of randomness in the laminar-turbulence transition, which is raised in the pipe flow experiment by Reynolds as a century old unresolved problem. Although there exist different hypotheses, it is widely believed that the randomness is "intrinsic", which, however, remains as an open question to be verified. Simulating the modeled RayleighB′enard convection system by means of the so-called clean numerical simulation(CNS) with negligible numerical noises that are smaller even than thermal fluctuation, we verify that turbulence can be self-excited from the inherent thermal fluctuation without any external disturbances, i.e. out of nothing. This reveals a relationship between microscopic physical uncertainty and macroscopic randomness. It is found that in physics the system nonlinearity functions as a channel for randomness information,and energy as well, to transport microscopic uncertainty toward large scales. Such scenario can generally be helpful to understand the various relevant phenomena. In methodology, compared with direct numerical simulation(DNS), CNS opens a new direction to investigate turbulent flows with largely improved accuracy and reliability.     

Ignominy：a Tool for Software Dependency and Metric Analysis with Examples from Large HEP Packages

Ignominy is a tool developed in the CMS IGUANA project to analyse the structure of software systems.Its primary component is a dependency scanner that distills information into human-usable forms.It also includes several tools to visualise the collected data in the form of graphical views and numerical metrics.Ignominy was designed to adapt to almost any reasonable structure,and it has been used to analyse several large projects. The original purpose of Ignominy was to help us better ensure the quality of our own software,and in particular warn us about possible structureal problems early on .As a part of this activity it is now used as a standard part of our release procedure,we also use it to evaluate and study the quality of external packages we plan to make use of .We describe what Ignominy can find out,and how if can be used to ivsualise and assess a software structure.We also discuss the inherent problems of the analysis as well as the different approaches to modularity the tool makes quite evident.The focus is the illustration of these issues through the analysis results for several sizable HEP softwre projects.     

Current-driven transformations of a skyrmion tube and a bobber in stepped nanostructures of chiral magnets

Magnetic skyrmion tubes and bobbers are two types of different nanoscale spin configurations that can coexist in nanostructures of chiral magnets.They are then proposed to be utilized as binary bits to build racetrack memory devices.The ability to manipulate the two magnetic objects controllably by current in nanostructures is the prerequisite to realize the device.Here,we demonstrate by numerical simulations that a magnetic bobber and a skyrmion tube can be transformed to each other using spinpolarized current in nanostripes with stepped shape.We also show such stepped nanostructures can be readily applied as the write head for the skyrmion-bobber-based racetrack memory.     

Integration of Geant4 with the Gaudi Framework

The GAUDI software framework is to be used for all event-processing applications in the LHCb experiment.The GEANT4 toolkit has been integrated into GAUDI to form the basis of the LHCb simulation program GAUSS.The benefits of this approach are that it permits re-use of basic services,such as persistency,interactivity and data visualization,as well as physics algorithms that were originally developed in the context of the reconstruction and analysis programs.Following the GAUDI philosophy,the integration has been achieved by developing a number of services with abstract interfaces that can be plugged in at run-time.We describe the overall design and details of the components for interfacing the detector geometry,the primary interaction and the output from tracking particles through the detector.     

Software Process Improvement in CMS—Are we Different？

One of the most challenging issues faced in HEP in recent years is the question of how to capitalise on software development and maintenance experience in a continuous manner.To capitalise inour context means to evaluate and apply new technologies as they arise,and to further evolve technologies arlready widely in use,It also implies the definition and adoption of standards,while ensuring reproducibility and quality of results.The CMS process improvement effort is two-pronged.It aims at continuous improve ment of the ways we do Object Oriented software,as well as continuous improvement in the efficiency of the working enviuronment.In particular the use and creation of de-facto software process standards within CMS has proven to be key to our successful software process improvement program.We describe the successful CMS implementation of a software process improvement strategy,following ISO 15504 since three years.We give the current status of the most important processes families formally established in CMS,and provide the guidelines we followed both for tool development,and methodology establishment.     

Putting It All Together：Experience and Challenges at the DELPHI off—line Processing Farm

After over 10 years of existence,DELPHI off-line software counts altogether over 1500k lines.Being written by multitude of authorsk,many of them having already left,it is very incoherent and extremely difficult to maintain:it is written in Fortran,it relies on obsolete tools and it has to run in a distributed multi-os computing environment.Still.as the analysis of LEP data will continue during the next 5-6 years,this code will have to be used and be ported to yet another platforms.In order to ensure high efficiency in use of our resources,we have developed several tools which hide from the user most of the intricaices of the operating system,batch system and data access.These tools are well integrated and easy to maintain.As the problems are quite typical for the High Energy Physics software,we believe that the ideas we have implemented can be useful also for the next generation of experiments.     

Benchmark solutions for MHD solver development

A benchmark solution is of great importance in validating algorithms and codes for magnetohydrodynamic(MHD) flows.Hunt and Shercliff’s solutions are usually employed as benchmarks for MHD flows in a duct with insulated walls or with thin conductive walls,in which wall effects on MHD are represented by the wall conductance ratio.With wall thickness resolved,it is stressed that the solution of Sloan and Smith’s and the solution of Butler’s can be used to check the error of the thin wall approximation condition used for Hunt’s solutions.It is noted that Tao and Ni’s solutions can be used as a benchmark for MHD flows in a duct with wall symmetrical or unsymmetrical,thick or thin.When the walls are symmetrical,Tao and Ni’s solutions are reduced to Sloan and Smith’s solution and Butler’s solution,respectively.     

Probabilistic Implementation of Non-Local CNOT Operation and Entanglement Purification

We propose a protocol for implementation of nonlocal CNOT operation using a partially entangled channel and show that when partially entangled pairs are taken as quantum channels, the nonlocal CNOT operation can be implemented probabilistically by introducing a collective unitary transformation. The required resources for implementation of the nonlocal CNOT operation in this case are discussed. We also point out that the nonlocal CNOT operation can be used as a puritlcation protocol to concentrate entanglement from an ensemble of partially entangled particles into a subensemble of maximally entanglement ones.     

Critical temperature and condensed fraction of Bose-Einstein condensation in optical lattices

Critical temperature and condensate fraction of Bose-Einstein condensation in the optical lattice are studied. The results show that the critical temperature in optical lattices can be characterized with an equivalent critical temperature in a single lattice, which provide a fast evaluation of critical temperature and condensate fraction of Bose-Einstein condensation confined with pure optical trap. Critical temperature can be estimated with an equivalent critical temperature. It is predicted that critical temperature is proportional to q in q number lattices for superfluid state and should be equal to that in a single lattic for Mott insulate state. Required potential depth or Rabi frequency and maximum atom number in the lattices both for superfluid state and Mott state are presented based on views of thermal mechanical statistics.     

Taming desynchronized bursting with delays in the Macaque cortical network

Inhibitory coupled bursting Hindmarsh-Rose neurons are considered as constitutive units of the Macaque cortical network. In the absence of information transmission delay the bursting activity is desynchronized,giving rise to spatiotemporally disordered dynamics. This paper shows that the introduction of finite delays can lead to the synchronization of bursting and thus to the emergence of coherent propagating fronts of excitation in the space-time domain. Moreover,it shows that the type of synchronous bursting is uniquely determined by the delay length,with the transitions from one type to the other occurring in a step-like manner depending on the delay. Interestingly,as the delay is tuned close to the transition points,the synchronization deteriorates,which implies the coexistence of different bursting attractors. These phenomena can be observed by different but fixed coupling strengths,thus indicating a new role for information transmission delays in realistic neuronal networks.     

A Distributed Agent—based Architecture for Dynamic Services

Aprototype system for agent-based distributed dynamic services that will be applied to the development of Data Grids for high-energy physics is presented.The agent-based systems we are designing and develogping gather,disseminate and coordinate configuration ,time-dependent state and other information in the Grid system as a whole.These systems are being developed as an enabling technology for workflow-management and other forms of end-to-end Grid system monitoring and management.This prototype is being developed in Java and is based on the JINI,Mobile Agents,Self-Organizing Neural Networks.     

On the realization of atomic dipole squeezing by remote manipulation

A scheme for adjusting the dipole squeezing properties of one atom at one place by manipulating and detecting another atom at the remote place is proposed, in which these atoms initially in the spatially separated entangled state act as a quantum channel carrying quantum information. The result shows that the dipole squeezing properties of one atom can be adjusted by rotating and detecting the other, and the maximal atomic squeezing can be obtained under local operation and classical communication.     

A Parametric Dynamic Model of Dark Energy

The double complex symmetric gravitational theory is extended to the parametric symmetric gravitational theory by introducing a parameter β. Hence parametric Friedmann-Robertson-Walker equations are obtained and some characters of dark energy in corresponding spaces are discussed by taking different values of β. In our method some previous results can be included as the special case of our results. It is worth noting that some characters of dark energy can be more intuitively described in our model. By analysis, we can predict that the fate of universe would be a Big Rip in the future, and also find that the state parameters for the two different constraint conditions wФ are consistent with the present cosmological observations.     

Phase retrieval algorithm for optical information security

As a typical technology for optical encryption, phase retrieval algorithms have been widely used in optical information encryption and authentication systems. This paper presents three applications of two-dimensional(2D) phase retrieval for optical encryption and authentication: first, a hierarchical image encryption system, by which multiple images can be hidden into cascaded multiple phase masks; second, a multilevel image authentication system, which combines(t, n) threshold secret sharing(both t and n are positive integers, and t ≤ n) and phase retrieval, and provides both high-level and low-level authentication; and finally, a hierarchical multilevel authentication system that combines the secret sharing scheme based on basic vector operations and the phase retrieval, by which more certification images can be encoded into multiple cascaded phase masks of different hierarchical levels. These three phase retrieval algorithms can effectively illustrate phase-retrievalbased optical information security. The principles and features of each phase-retrieval-based optical security method are analyzed and discussed. It is hoped that this review will illustrate the current development of phase retrieval algorithms for optical information security and will also shed light on the future development of phase retrieval algorithms for optical information security.     

Knowledge Management and Electronic Publishing for the CNAO with EDMS

The Italian Government has recently approved the construction of a National Center for Oncological Hadrontherapy(CNAO),TERA(Foundation for Oncological Hadrontherapy)will lead the high technology projects of the CNAO,whose machine design is a spin-off to the medical world of the collaboration with CERN.The CERN EDMS(Engineering Data Management System)was initially launched at CERN to support the LHC project but has since become a general service available for all divisions and recognized experiments.As TERA is closely associated to CERN,TERA decided to profit from EDMS and to use it to support the ambitious Quality Assurance plan for the CNAO project.With this EDMS project TERA transfers know-how that has been developed in the HEP Community to a social sector of major importance that also has high-density information management needs.The features available in the CERN EDMS system provide the tools for managing the complete lifecycle of any technical document including a distributed approval process and a controlled distributed collaborative work environment using the World Wide Web.The system allows management of structures representing projects and relative documents including drawings within working contexts and with a customizable release procedure.TERA is customizing CERN EDMS to document the CNAO project activities,to ensure that the medical accelecrator and its auxiliary installations can be properly managed throughout its lifecycle,from design to maintenance and possibly dismantling.The technical performance requirements of EDMS are identical to those for LHC and CERN in general.We will describe what we have learned about how to set-up an EDMS project,and how it benefits a challenging initiative like the CNAO Project of the TERA collaboration.The knowledge managed by the system will facilitate later installations of similar centers (planned for Lyon and Stockholm)and will allow the reuse of experience gained in Italy.     

Spin-dependent transport induced by magnetization in zigzag graphene nanoribbons coupled to one-dimensional leads

We study spin transport in a zigzag graphene nanoribbon sample with two ferromagnetic strips deposited on the two sides of the ribbon.A tight-binding Hamiltonian was adopted to describe the sample connected to two onedimensional leads.Our theoretical study shows that the resonance peaks of conductance for the spin-up and spin-down electrons are separated for the parallel configuration of the ferromagnetic strips,while they are not separated for the case of antiparallel configuration.This means that giant magnetoresistance can be produced at particular energies by altering the configurations of the ferromagnetic strips,and the device can be designed as a spin filter.     

GENERALIZED GREEN''''S FUNCTIONS OF SURFACE EXCITATION OF ELASTIC WAVE FIELDS IN A PIEZOELECTRIC HALF-SPACE

Since the generalized Green's functions,which correspond to surface excitation of elastic wavefields in a half-space of piezoelectric crystal,are independent of excitation conditions and only depen-dent on material parameters and orientation,they can be investigated in advance and independently. It is shown that the generalized Green's functions can be written as a sum of three parts repre-senting separately a surface wave,a bulk wave and an electrostatic effect. We also confirm that the surface wave part and the bulk wave part at the far field of the generalizedGreen's functions can be expressed by analytical expressions,and thus,the surface wave field and thefar field of bulk wave among the excited elastic wave fields can be evaluated exactly. Finally,as an example,the generalized Green's functions for the 6 mm crystal are given.     

Studies for Optimization of Data Analysis Queries for HEP Using HERA—B Commissioning Data

In this paper we present an overview of the ongoing studies to build up a framework that supports the analysis after the reprocessing phase.This framework aims to develop a standard data query language for the HEP community,The related studies have been considering the relational database model as possible approach opposed to the object model.Several optimizing and tunning techniques are being used in technologies like DB2[3],Oracle[5] and Root[2],that are simultaneously being evaluated.The experience obtained can be seen as a valuable testbed for the future LHC and simultaneously as interesting input for the development of the GRID.     

Information Erasure and Recovery in Quantum Memory

We show that information in quantum memory can be erased and recovered perfectly if it is necessary. The fact that the final states of environment are completely determined by the initial states of the system allows an erasure operation to be realized by a swap operation between the system and an ancilla. Therefore, the erased information can be recovered. When there is an irreversible process, e.g. an irreversible operation or a decoherence process, in the erasure process, the information would be erased perpetually. We present that quantum erasure will also give heat dissipation in the environment. A classical limit of quantum erasure is given to coincide with Landauer‘s erasure principle.