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.     

DEPUTY：Analysing Architectural Structures and Checking Style

The DepUty(dependencies utility)can be classified as a project and process management tool.The main goal of DepUty is to assist by means of source code analysis and graphical representation using UML,in understanding dependencies of sub-systems and packages in CMS object Oriented software,to understand architectureal structure,and to schedule code release in modularised integration.It also allows a new-comer to more easily understand the global structure, of CMS software,and to void circular dependencies up-front or re-factor the code,in case it was already too close to the edge of non-maintainability.We will discuss the various views DepUty provides to analyse package dependencies and illustrate both the metrics and style checking facilities it provides.     

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.     

Implementation of LDA+DMFT with the pseudo-potential-plane-wave method

We propose an efficient implementation of combining dynamical mean field theory(DMFT) with electronic structural calculation based on the local density approximation(LDA).The pseudo-potential-plane-wave method is used in the LDA part,which enables it to be applied to large systems.The full loop self consistency of the charge density has been reached in our implementation,which allows us to compute the total energy related properties.The procedure of LDA+DMFT is introduced in detail with a complete flow chart.We have also applied our code to study the electronic structure of several typical strong correlated materials,including cerium,americium and NiO.Our results fit quite well with both the experimental data and previous studies.     

Quasispecies distribution of Eigen model

We have studied sharp peak landscapes of the Eigen model from a new perspective about how the quasispecies are distributed in the sequence space. To analyse the distribution more carefully, we bring in two tools. One tool is the variance of Hamming distance of the sequences at a given generation. It not only offers us a different avenue for accurately locating the error threshold and illustrates how the configuration of the distribution varies with copying fidelity $q$ in the sequence space, but also divides the copying fidelity into three distinct regimes. The other tool is the similarity network of a certain Hamming distance $d_{0}$, by which we can gain a visual and in-depth result about how the sequences are distributed. We find that there are several local similarity optima around the centre (global similarity optimum) in the distribution of the sequences reproduced near the threshold. Furthermore, it is interesting that the distribution of clustering coefficient $C(k)$ follows lognormal distribution and the curve of clustering coefficient $C$ of the network versus $d_{0}$ appears to be linear near the threshold.     

Effect of a two-phase wedge-sliding model on the ingredient drift of a stable mixed fluid and its computing method

A two-phase wedge-sliding model is developed based on the micro-cellular structure and minimum entropy theory of a stable system,and it is used to describe the ingredient distribution of a mixed fluid in a non-uniform stress field and to analyse its phase drift phenomenon.In the model,the drift-inhibition angle and the expansion-inhibition angle are also deduced and used as evaluating indexes to describe the drifting trend of different ingredients among the mixed fluids.For solving above two indexes of the model,a new calculation method is developed and used to compute the phase distributions of multiphase fluid at peak stress and gradient area stress,respectively.As an example,the flow process of grease in a pipe is analysed by simulation method and used to verify the validity of the model.     

Detection of a Physical Difference between the CDM Halos in Simulation and in Nature

Numerical simulation is an important tool that is helpful for us to understand the process of structure formation in the universe. However, many simulation results of cold dark matter （CDM） halos on a small scale are inconsistent with observations： the central density profile is too cuspy and there are too many substructures, Here we point out that both the problems may be connected with a hitherto unrecognized bias in the simulated halos. Although CDM halos in nature and in simulation are both virialized systems of collisionless CDM particles, gravitational encounter cannot be neglected in the simulated halos because they contain many fewer particles. We demonstrate this by two numerical experiments, showing that there is a difference on the microcosmic scale between the natural and simulated halos. The simulated halo is more akin to globular clusters where gravitational encounter is known to lead to such drastic phenomena as core collapse. Such an artificial core collapse process appears to link the two problems together in the bottom-up scenario of structure formation in the ACDM universe. The discovery of this bias also has implications on the applicability of the Jeans theorem in galactic dynamics.     

Do we need to use regularization for the thermal part in the NJL model?

The Nambu–Jona-Lasinio(NJL)model is one of the most useful tools for studying non-perturbative strong interactions in matter.Because it is a nonrenormalizable model,the choice of regularization is a subtle issue.In this paper,we discuss one of the general issues regarding regularization in the NJL model,which is whether we need to use regularization for the thermal part by evaluating the quark chiral condensate and thermal properties in the two-flavor NJL model.The calculations in this work include three regularization schemes that contain both gauge covariant and invariant schemes.We found that,regardless of the regularization scheme we choose,it is necessary to use regularization for the thermal part when calculating physical quantities related to the chiral condensate and to not use regularization for the thermal part when calculating physical quantities related to the grand potential.     

Code Organization and Configuration Management

Industry experts are increasingly focusing on team productivity on team productivity as the key to success,the base of the team effort is the four-fold structure of software in terms of logical organisation,physical organisation,managerial organisation,and dynamical structure.We describe the ideas put into action within the CMS software for organising software into sub-systems and packages,and to establish configuration management in a multiproject environment.We use a structure that allows to maximise the independence of soft ware development in individual areas,and at the same time emphasises the overwhelming importance of the interdependencies between the packages and components in the system.We comment on release procedures,and describe the inter-relationship between release,development,integration,and testing.     

Electric and Magnetic Properties of a New Ferrite—Ceramic Composite Material

We have investigated a new ferrite-ceramic composite material with inductive and capacitive properties fabricated by a solid-state reaction method.We analyse the effects of the composite mechanism and microstructure on the magnetic and electric properties.The results show that the new materials can be used not only as inductor materials,but also as capacitor materials in the wide frequency range of 1kHz-1.8GHz.The real part of permeability of the composite material is between 10 and 5.6,the imaginary part of permeability is between 1.2 and 0.5,and the dielectric constant is about ten times larger than that of ordinary ferrite materials.It is suggested that the new composite materials will be widely used in anti-electromagnetic interference fields and radio frequency communication fields.     

COMPUTER SIMULATION OF VISCOUS FINGERING IN SIERPINSKI CARPET

A new method—mapping dilation method is proposed in this paper to construct Sierpinski carpet. Viscous fingering (VF) in Sierpinski carpet, based on the assumption that bond radii are beta distribution, is investigated by means of successive over-relaxation techniques. The topology and the geometry of the porous media have a strong effect on displacement processes. In the Sierpinski network, the VF pattern of porous media in the limit M→∞ is found to be similar to the diffusion-limited-aggregation pattern. The fractal dimension for VF in fractal space is calculated and the fractal dimension D can be reasonably regarded as a useful parameter to evaluate the sweep efficiencies and oil recoveries. We have also found that the geometry of the porous medium also has strong effects on the displacement processes and the structure of the VF. Moreover, we find that the sweep efficiency of the displacement processes mainly depends upon the length of the network system and also on the viscosity ratio M. This shows that the current method can be used to solve VF problems in complex structures if the structures are self-similar, or they can be reduced to a self-similar structure.     

Emittance Measurements for Beams Extracted from LECR3 Ion Source

High quality ion beams are required by IMP cyclotron and atomic physics research, so it is important to research and measure beam emitt ance of ECR ion source. Intense beams extracted from ECR ion source usually have low energy, so it is suitable to use Electric-Sweep Scanner to measure the emittance. This kind of measurement is popularly used at ECR ion source, and it has some prominent merits such as high accuracy, very short time of data processing and easy expressing of the emittance pattern. So we designed and built this emittance scanner to measure emittance of the ion beams produced by LECR3 ion source. The structure of the ESS is shown in Fig.l, and the photo of the ESS is shown in Fig.2.     

Gravitational coupling,dynamical changes of units and the cosmological constant problem

A spacetime interval connecting two neighbouring points can be measured in different unit systems.For instance,it can be measured in atomic unit defined in terms of fundamental constants existing in quantum theories.It is also possible to use a gravitational unit which is defined by the use of properties of macroscopic objects.These two unit systems are usually regarded as indistinguishable up to a constant conversion factor.Here we consider the possibility that these two units are related by an epoch-dependent conversion factor.This is a dynamical changes of units.Regarding a conformal transformation as a local unit transformation,we use a gravitational model in which the gravitational and the matter sectors are given in different conformal frames(or unit systems).It is relevant to the cosmological constant problem,namely the huge discrepancy between the estimated and the observational values of the cosmological constant in particle physics and cosmology,respectively.We argue that the problem arises when one ignores evolution of the conversion factor relating the two units during expansion of the Universe.Connection of the model with violation of equivalence principle and possible variation of fundamental constants are also discussed.     

Electrochromic & magnetic properties of electrode materials for lithium ion batteries

Progress in electrochromic lithium ion batteries(LIBs) is reviewed, highlighting advances and possible research directions. Methods for using the LIB electrode materials' magnetic properties are also described, using several examples.Li_4Ti_5O_(12)(LTO) film is discussed as an electrochromic material and insertion compound. The opto-electrical properties of the LTO film have been characterized by electrical measurements and UV–Vis spectra. A prototype bi-functional electrochromic LIB, incorporating LTO as both electrochromic layer and anode, has also been characterized by charge–discharge measurements and UV–Vis transmittance. The results show that the bi-functional electrochromic LIB prototype works well. Magnetic measurement has proven to be a powerful tool to evaluate the quality of electrode materials. We introduce briefly the magnetism of solids in general, and then discuss the magnetic characteristics of layered oxides, spinel oxides, olivine phosphate Li Fe PO_4, and Nasicon-type Li_3Fe_2(PO_4)_3. We also discuss what kind of impurities can be detected, which will guide us to fabricate high quality films and high performance devices.     

The IGUANA Interactive Graphics TOolkit with Examples from CMS and D0

IGUANA（Interactive Graphics for User ANAlysis)is a C toolkit for developing graphical user interfaces and high performance 2-D and 3-D graphics applications,such as data browsers and detector and event visualisation programs.The IGUANA strategy is to use freely available software(e.g.Qt,SoQt,OpenInventor,OpenGL,HEPVis)and package and extend it to provide a general-purpose and experiment-independent toolkit.We describe the evaluation and choices of publicly available GUI/graphics software and the additional functionality currently provided by IGUANA.We demonstrate the use of IGUANA with several applications built for CMS and D0.     

Design of Photonic Bandgap Fibre with Novel Air-Hole Structure

We introduce PBGFs with the cladding made of our newly designed quasi-hexagonal air holes and demonstrate how it actually operates. This cladding structure is introduced for the first time to the best of our knowledge, and is realized by making use of the hydrofluoric acid＇s corrosive properties. The fibre corrosion can be accurately controlled, thus opening us the gate for the design and fabrication of new PB. GFs with more complex and more efficient cladding structures. Numerical results and actual simulations indicate that PBGFs built with this cladding structure have improved b~dgap properties and guiding bands as wide as 500 nm have been theoretically reached. Using the same method, we have also been able to design two other types of PBGFs with improved cladding structure.     

Towards a gravitation theory in Berwald-Finsler space

Finsler geometry is a natural and fundamental generalization of Riemann geometry. The Finsler structure depends on both coordinates and velocities. It is defined as a function on tangent bundle of a manifold. We use the Bianchi identities satisfied by the Chern curvature to set up a gravitation theory in Berwald-Finsler space. The geometric part of the gravitational field equation is nonsymmetric in general. This indicates that the local Lorentz invariance is violated.     

An Electronic Logbook for the HEP Control Room

The Control Room Logbook(CRL)is designed to improve and replace the paper logbooks traditionally used in the HEP accelerator control room.Its features benefit the on-line coordinator,the shift operators,and the remote observers,This paper explains some of the most attractive features for each of these roles.The features include the ability to configure the logbook for the specific needs of a collaboration,a large variety of entry types operator can add by simply clicking and dragging,and a flexible web interface for the remote observer to keep up with control room activities.The entries are saved as UTF-8 based XML files,which allowed us to give the data structure and meaning such that it can easily be parsed in the present and far into the future.The XML tag data is also indexed in a relational database,making queries on dates,keyworks,entry type and other criteria feasible and fast .The CRL is used in the D0 control room.This presentation also discusses our experience with deployment,platform independence and other interesting issues that arose with the installation and use of logbook.     

Pattern recognition and data mining software based on artificial neural networks applied to proton transfer in aqueous environments

In computational physics proton transfer phenomena could be viewed as pattern classification problems based on a set of input features allowing classification of the proton motion into two categories： transfer ＇occurred＇ and transfer ＇not occurred＇. The goal of this paper is to evaluate the use of artificial neural networks in the classification of proton transfer events, based on the feed-forward back propagation neural network, used as a classifier to distinguish between the two transfer cases. In this paper, we use a new developed data mining and pattern recognition tool for automating, controlling, and drawing charts of the output data of an Empirical Valence Bond existing code. The study analyzes the need for pattern recognition in aqueous proton transfer processes and how the learning approach in error back propagation （multilayer perceptron algorithms） could be satisfactorily employed in the present case. We present a tool for pattern recognition and validate the code including a real physical case study. The results of applying the artificial neural networks methodology to crowd patterns based upon selected physical properties （e.g., temperature, density） show the abilities of the network to learn proton transfer patterns corresponding to properties of the aqueous environments, which is in turn proved to be fully compatible with previous proton transfer studies.