Switching magnetic vortex core by a single nanosecond current pulse

In a ferromagnetic nanodisk, the magnetization tends to swirl around in the plane of the disk and can point either up or down at the center of this magnetic vortex. This binary state can be useful for information storage. It is demonstrated that a single nanosecond current pulse can switch the core polarity. This method also provides the precise control of the core direction, which constitutes fundamental technology for realizing a vortex core memory.Comment: 13 pages, 4 figure

Statistical Maintenance Time Estimation Based on Stochastic Differential Equation Models in OSS Development Project

At present, the method of earned value management is often applied to the actual software projects in various IT companies. Also, open source software (OSS) are used under the various situations, because the OSS are useful for many users to make a cost reduction, standardization of systems, and quick delivery. Many OSS are developed under the peculiar development style known as bazaar method. According to the bazaar method, many faults are detected and fixed by developers around the world, and the fixed result will be reflected in the next release. In this paper, we discuss an OSS effort estimation model by using a conventional stochastic differential equation model. Moreover, we propose an optimal maintenance problem based on the proposed effort estimation model. Then, we discuss the optimal maintenance problem minimizing the maintenance effort and satisfying the earned value requirement, simultaneously. In addition, we also propose a method of judging whether the optimal maintenance time is an appropriate time from the viewpoint of the transition probability distribution of the cumulative number of maintenance effort, because proper management of maintenance effort affects software quality. Furthermore, several numerical examples of optimal maintenance time problem with earned value requirement are shown by using the effort data under actual OSS projec

One-loop determination of mass dependent O(a)O(a) improvement coefficients for the heavy-light vector and axial-vector currents with relativistic heavy and domain-wall light quarks

We present the one-loop results of the mass dependent $O(a)$ improvement coefficients for the heavy-light vector and axial-vector currents consisting of the relativistic heavy and the domain-wall light quarks. The calculations are performed with the plaquette, Iwasaki and DBW2 gauge actions. The heavy quark mass and domain-wall height dependence is investigated. We point out that the exact chiral symmetry held by the lattice light quark action leads to an exact relation between the improvement coefficients for the vector and axial-vector currents without regard to the lattice heavy quark action.Comment: 3 pages, 1 figure, talk presented at Lattice2004(improved), Fermilab, June 21-26, 200

Deep Learning Based on Fine Tuning with Application to the Reliability Assessment of Similar Open Source Software

Recently, many open-source products have been used under the situations of general software development, because the cost saving and standardization. Therefore, many open-source products are gathering attention from many software development companies. Then, the reliability/quality of open-source products becomes very important factor for the software development. This paper focuses on the reliability/quality evaluation of open-source products. In particular, the large quantity fault data sets recorded on Bugzilla of open-source products is used in many open-source development projects. Then, the large amount of data sets of software faults is recorded on the Bugzilla. This paper proposes the reliability/quality evaluation approach based on the deep machine learning by using the large quantity fault data on the Bugzilla. Moreover, the large quantity fault data sets are analyzed by the deep machine learning based on the fine-tuning

Perturbative determination of mass dependent renormalization and improvement coefficients for the heavy-light vector and axial-vector currents with relativistic heavy and domain-wall light quarks

We determine the mass dependent renormalization as well as improvement coefficients for the heavy-light vector and axial-vector currents consisting of the relativistic heavy and the domain-wall light quarks through the standard matching procedure. The calculation is carried out perturbatively at the one loop level to remove the systematic error of O(\alpha_s (am_Q)^n a\p) as well as $O(\alpha_s (am_Q)^n)$ ($n\ge$0), where \p is a typical momentum scale in the heavy-light system. We point out that renormalization and improvement coefficients of the heavy-light vector current agree with those of the axial-vector current, thanks to the exact chiral symmetry for the light quark. The results obtained with three different gauge actions, plaquette, Iwasaki and DBW2, are presented as a function of heavy quark mass and domain-wall height.Comment: 33 pages, 6 figure