The role of structural embeddedness in an IT outsourcing network

The design of governance to safeguard against a vendor's opportunistic behaviour is one of the critical issues in information technology outsourcing (ITO) since this behaviour causes cost escalation and service debasement. The roles of structural embeddedness underlying network governance have been gaining its importance as complementary or substitutable governance in ITO. Our research attempts to reveal how structural embeddedness can affect the decision-makings of clients and vendors and their resulting outcomes in an ITO network and how these effects are moderated by various ITO network structures according to outsourced IT services. An agent-based simulation and game-theoretic approach are adopted to build a simulation model to describe ITO networks with various structures and ITO transactions between clients and vendors. Finally, the future research directions are discussed

Rainbow Graphs and Switching Classes

A rainbow graph is a graph that admits a vertex-coloring such that every color appears exactly once in the neighborhood of each vertex. We investigate some properties of rainbow graphs. In particular, we show that there is a bijection between the isomorphism classes of n-rainbow graphs on 2n vertices and the switching classes of graphs on n vertices.Comment: Added more reference, fixed some typos (revision for journal submission

Current and noise expressions for radio-frequency single-electron transistors

We derive self-consistent expressions of current and noise for single-electron transistors driven by time-dependent perturbations. We take into account effects of the electrical environment, higher-order co-tunneling, and time-dependent perturbations under the two-charged state approximation using the Schwinger-Kedysh approach combined with the generating functional technique. For a given generating functional, we derive exact expressions for tunneling currents and noises and present the forms in terms of transport coefficients. It is also shown that in the adiabatic limit our results encompass previous formulas. In order to reveal effects missing in static cases, we apply the derived results to simulate realized radio-frequency single-electron transistor. It is found that photon-assisted tunneling affects largely the performance of the single-electron transistor by enhancing both responses to gate charges and current noises. On various tunneling resistances and frequencies of microwaves, the dependence of the charge sensitivity is also discussed.Comment: 18 pages, 9 figure

On the Design of Secure Full-Duplex Multiuser Systems under User Grouping Method

Consider a full-duplex (FD) multiuser system where an FD base station (BS) is designed to simultaneously serve both downlink users and uplink users in the presence of half-duplex eavesdroppers (Eves). Our problem is to maximize the minimum secrecy rate (SR) among all legitimate users by proposing a novel user grouping method, where information signals at the FD-BS are accompanied with artificial noise to degrade the Eves' channel. The SR problem has a highly nonconcave and nonsmooth objective, subject to nonconvex constraints due to coupling between the optimization variables. Nevertheless, we develop a path-following low-complexity algorithm, which invokes only a simple convex program of moderate dimensions at each iteration. We show that our path-following algorithm guarantees convergence at least to a local optima. The numerical results demonstrate the merit of our proposed approach compared to existing well-known ones, i.e., conventional FD and nonorthogonal multiple access.Comment: 6 pages, 3 figure

Evidence for the flavor singlet axial anomaly related effects in ϕ\phi meson electromagnetic production at large momentum transfers

The gluonic contributions to the conventional PCAC formulas due to flavor singlet axial anomaly have been instrumental in explaining the mass of the $\eta^{\prime}$ and providing a plausible explanation for solving the spin crisis. We show that they also play an important role in the description of photo- and electroproduction of vector mesons at low energy and high momentum transfers. We calculate the contributions of this type to $\phi$ meson electromagnetic production in a model, which contains also a soft pomeron, and find agreement with recent CLAS data.Comment: 13 pages, 6 figures, Latex; final version to appear in Phys. Lett.