Action-Angle Variables for Complex Projective Space and Semiclassical Exactness

We construct the action-angle variables of a classical integrable model defined on complex projective phase space and calculate the quantum mechanical propagator in the coherent state path integral representation using the stationary phase approximation. We show that the resulting expression for the propagator coincides with the exact propagator which was obtained by solving the time-dependent Schr\"odinger equation.Comment: 11 pages, Revtex 3.0, SNUTP-94-6

Phase Space Structure of Non-Abelian Chern-Simons Particles

We investigate the classical phase space structure of $N$ $SU(n+1)$ non-Abelian Chern-Simons (NACS) particles by first constructing the product space of associated $SU(n+1)$ bundle with ${\bf CP}^n$ as the fiber. We calculate the Poisson bracket using the symplectic structure on the associated bundle and find that the minimal substitution in the presence of external gauge fields is equivalent to the modification of symplectic structure by the addition of field strength two form. Then, we take a direct product of the associated bundle by the space of all connections and choose a specific connection by the condition of vanishing momentum map corresponding to the gauge transformation, thus recovering the quantum mechanical model of NACS particles in Ref.\cite{lo1}.Comment: 18 pages, REVTEX 3.0, SNUTP-93-4

Performance of SSE and AVX Instruction Sets

SSE (streaming SIMD extensions) and AVX (advanced vector extensions) are SIMD (single instruction multiple data streams) instruction sets supported by recent CPUs manufactured in Intel and AMD. This SIMD programming allows parallel processing by multiple cores in a single CPU. Basic arithmetic and data transfer operations such as sum, multiplication and square root can be processed simultaneously. Although popular compilers such as GNU compilers and Intel compilers provide automatic SIMD optimization options, one can obtain better performance by a manual SIMD programming with proper optimization: data packing, data reuse and asynchronous data transfer. In particular, linear algebraic operations of vectors and matrices can be easily optimized by the SIMD programming. Typical calculations in lattice gauge theory are composed of linear algebraic operations of gauge link matrices and fermion vectors, and so can adopt the manual SIMD programming to improve the performance.Comment: 7 pages, 5 figures, 4 tables, Contribution to proceedings of the 30th International Symposium on Lattice Field Theory (Lattice 2012), June 24-29, 201

Raising Skepticisms on the Feasibility of Algorithmic Tacit Collusion

Advances in artificial intelligence accelerate the digitization of pricing in various industry domains, from home appliances to hotels. At the same time, economic theories and legal cases claim that the advances benefit some players through synchronous algorithmic pricing, so-called Algorithmic Tacit Collusion (ATC). However, the previous studies rely on artificial intelligence’s broad collusion mechanisms in various pricing scenarios. The paper unravels the mixture of ATC problems by specifying the algorithmic pricing context in platform providers’ oligopoly and adjusting the underlying assumptions to the context. Our simulation of Iterative Prisoner’s Dilemma (IPD) games with various heterogeneous pricing algorithms show that ATC emerges in rare conditions (i.e., algorithm and information symmetries). Our findings suggest that understanding the technology and business architectures should precede deriving the theories of ATC and implementing the legal cases and policies of digitization for the next generation’s pricing

Towards Self-Awareness Privacy Protection for Internet of Things Data Collection

The Internet of Things (IoT) is now an emerging global Internet-based information architecture used to facilitate the exchange of goods and services. IoT-related applications are aiming to bring technology to people anytime and anywhere, with any device. However, the use of IoT raises a privacy concern because data will be collected automatically from the network devices and objects which are embedded with IoT technologies. In the current applications, data collector is a dominant player who enforces the secure protocol that cannot be verified by the data owners. In view of this, some of the respondents might refuse to contribute their personal data or submit inaccurate data. In this paper, we study a self-awareness data collection protocol to raise the confidence of the respondents when submitting their personal data to the data collector. Our self-awareness protocol requires each respondent to help others in preserving his privacy. The communication (respondents and data collector) and collaboration (among respondents) in our solution will be performed automatically

Light Emission from Graphene

Graphene has attracted great interest due to its superior and unique physical properties. The strong light‐matter interaction with ultrafast and broadband photoresponse of graphene has allowed for the development of state‐of‐the art optical components, such as photodetectors and optical modulators, making this material very promising for ultrafast optical communications. However, so far, light emission from graphene has remained elusive, although this would open the door towards obtaining atomically thin, flexible and transparent light sources and graphene‐based on‐chip interconnects. In this chapter, we review experimental results and techniques of the electrically driven light emission from graphene in the infrared and visible spectrum range