Explicit Multimonopole Solutions in SU(N) Gauge Theory

We construct multimonopole solutions containing N-1 distinct fundamental monopoles in SU(N) gauge theory. When the gauge symmetry is spontaneously broken to U(1)^{N-1}, the monopoles are all massive, and we show that the fields can be written in terms of elementary function for all values of the monopole positions and phases. In the limit of unbroken U(1) X SU(N-2) X U(1) symmetry, the configuration can be viewed as containing a pair of massive monopoles, each carrying both U(1) and SU(N-2) magnetic charges, together with N-3 massless monopoles that condense into a cloud of non-Abelian fields. We obtain explicit expressions for the fields in the latter case and use these to analyze the properties of the non-Abelian cloud.Comment: 22 pages, no figure

Dissipation Effects in Hybrid Systems

The dissipation effect in a hybrid system is studied in this Letter. The hybrid system is a compound of a classical magnetic particle and a quantum single spin. Two cases are considered. In the first case, we investigate the effect of the dissipative quantum subsystem on the motion of its classical partner. Whereas in the second case we show how the dynamics of the quantum single spin are affected by the dissipation of the classical particle. Extension to general dissipative hybrid systems is discussed.Comment: 4+ pages, 4 figure

Sutured Khovanov homology distinguishes braids from other tangles

We show that the sutured Khovanov homology of a balanced tangle in the product sutured manifold D x I has rank 1 if and only if the tangle is isotopic to a braid.Comment: 9 pages, 1 figure, Definition of sutured annular Khovanov homology in Section 2.1 has significant text overlap with arXiv:1212.2222; Version 2 incorporates referee comments. This is the version accepted for publication in Mathematical Research Letter

Communication in an "Officeless firm"

New technologies permit new types of organisations. This article describes and analyses one such organisation, an "officeless firm", where all employees work from their own homes and there is no central office. Drawing upon observations and interviews, the modes of communication and the nature of the interpersonal relationships that have permitted this organisation to succeed are described, along with the challenges that face this organisation in the future as it attempts to grow

A dubiety-determining based model for database cumulated anomaly intrusion

The concept of Cumulated Anomaly (CA), which describes a new type of database anomalies, is addressed. A typical CA intrusion is that when a user who is authorized to modify data records under certain constraints deliberately hides his/her intentions to change data beyond constraints in different operations and different transactions. It happens when some appearing to be authorized and normal transactions lead to certain accumulated results out of given thresholds. The existing intrusion techniques are unable to deal with CAs. This paper proposes a detection model, Dubiety-Determining Model (DDM), for Cumulated Anomaly. This model is mainly based on statistical theories and fuzzy set theories. It measures the dubiety degree, which is presented by a real number between 0 and 1, for each database transaction, to show the likelihood of a transaction to be intrusive. The algorithms used in the DDM are introduced. A DDM-based software architecture has been designed and implemented for monitoring database transactions. The experimental results show that the DDM method is feasible and effective

A pure-carbon ring transistor: The role of topology and structure

We report results on the rectification properties of a carbon nanotube (CNT) ring transistor, contacted by CNT leads, whose novel features have been recently communicated by Watanabe et al. [Appl. Phys. Lett. 78, 2928 (2001)]. This paper contains results which are validated by the experimental observations. Moreover, we report on additional features of the transmission of this ring device which are associated with the possibility of breaking the lead inversion symmetry. The linear conductance displays a "chessboard"-like behavior alternated with anomalous zero-lines which should be directly observable in experiments. We are also able to discriminate in our results structural properties (quasi-onedimensional confinement) from pure topological effects (ring configuration), thus helping to gain physical intuition on the rich ring phenomenology.Comment: 3 pages, 4 figure

Statistical and fuzzy approach for database security

A new type of database anomaly is described by addressing the concept of Cumulated Anomaly in this paper. Dubiety-Determining Model (DDM), which is a detection model basing on statistical and fuzzy set theories for Cumulated Anomaly, is proposed. DDM can measure the dubiety degree of each database transaction quantitatively. Software system architecture to support the DDM for monitoring database transactions is designed. We also implemented the system and tested it. Our experimental results show that the DDM method is feasible and effective