Understanding Electronic Commerce from a Historical Perspective

The aim of this paper is to use historical insights from modern commerce as entry points to examine the macro-level phenomena associated with electronic commerce (EC). Commerce in its modern form first appeared in early 13th century Italy where conducive political conditions existed. Trade facilitated the exchange of goods, thereby enhancing the efficiency of processes between production and consumption. Even more important was its role in raising the level of human capital, promoting the spread of ideas and information, changing people\u27s attitudes and behaviour. Some modern business practices and institutions which evolved with modern commerce are bookkeeping, modern banking, commodities market, putting out systems (or outsourcing as we know it now), insurance, stock exchange, and venture capital. The current historical context favorable to EC is globalization. The emergence of network organizations helped to establish some of the practices supporting business-to-business electronic commerce. EC holds the potential to reduce time and transaction costs. However, the historical perspective suggests that the most profound implications of EC are likely to be at the macro-level or socio-institutional level. Some implications can already be seen while others are still developing. We are witnessing the impacts of EC on older business practices, and business models while there are likely implications for business cycles Such a perspective can provide pointers for future research. Lessons from history suggest a need to pay due attention to intervention at the socio-institutional level to reap the benefits of this form of commerce

Deterministic quantum teleportation between distant atomic objects

Quantum teleportation is a key ingredient of quantum networks and a building block for quantum computation. Teleportation between distant material objects using light as the quantum information carrier has been a particularly exciting goal. Here we demonstrate a new element of the quantum teleportation landscape, the deterministic continuous variable (cv) teleportation between distant material objects. The objects are macroscopic atomic ensembles at room temperature. Entanglement required for teleportation is distributed by light propagating from one ensemble to the other. Quantum states encoded in a collective spin state of one ensemble are teleported onto another ensemble using this entanglement and homodyne measurements on light. By implementing process tomography, we demonstrate that the experimental fidelity of the quantum teleportation is higher than that achievable by any classical process. Furthermore, we demonstrate the benefits of deterministic teleportation by teleporting a dynamically changing sequence of spin states from one distant object onto another

Generalized thermo vacuum state derived by the partial trace method

By virtue of the technique of integration within an ordered product (IWOP) of operators we present a new approach for deriving generalized thermo vacuum state which is simpler in form that the result by using the Umezawa-Takahashi approach, in this way the thermo field dynamics can be developed. Applications of the new state are discussed.Comment: 5 pages, no figure, revtex

Null-stream veto for two co-located detectors: Implementation issues

Time-series data from multiple gravitational wave (GW) detectors can be linearly combined to form a null-stream, in which all GW information will be cancelled out. This null-stream can be used to distinguish between actual GW triggers and spurious noise transients in a search for GW bursts using a network of detectors. The biggest source of error in the null-stream analysis comes from the fact that the detector data are not perfectly calibrated. In this paper, we present an implementation of the null-stream veto in the simplest network of two co-located detectors. The detectors are assumed to have calibration uncertainties and correlated noise components. We estimate the effect of calibration uncertainties in the null-stream veto analysis and propose a new formulation to overcome this. This new formulation is demonstrated by doing software injections in Gaussian noise.Comment: Minor changes; To appear in Class. Quantum Grav. (Proc. GWDAW10

The Characterization of J-Integral for Elastic-Plastic Crack Growth Evaluation using Finite Element Analysis

J-integral is a fracture mechanic parameter that can be used to characterize elastic-plastic fracture mechanic (EPFM) behavior. The path independent characteristic in J-integral is proposed by Rice [1], and it is widely used in a lot of research. Another approach is the load-displacement approach, where the J-integral is calculated by the area under the load-displacement curve. However, the validity of the J-integral value by load-displacement approach is yet to be confirmed. This paper is aimed to investigate the effect of crack length ratio of CT specimen to J-integral value by two approaches: path-integral approach and load-displacement approach. Finite element analysis of compact tension (CT) model with crack length ratio a/W between 0.2 to 0.5 was carried out under displacement δ between 0.2 to 1.0 mm using ANSYS parametric design language (APDL). The J value by path integral approach, Jpath is compared to the value calculated from load-displacement approach, Jp-d. It was found that path independency occurs for J value evaluated from path integral approach. A correction factor needs to be introduced since the load-displacement approach cannot be used for shallow crack cases

Acquire information about neutrino parameters by detecting supernova neutrinos

We consider the supernova shock effects, the Mikheyev-Smirnov-Wolfenstein (MSW) effects, the collective effects, and the Earth matter effects in the detection of type II supernova neutrinos on the Earth. It is found that the event number of supernova neutrinos depends on the neutrino mass hierarchy, the neutrino mixing angle $\theta_{13}$, and neutrino masses. Therefore, we propose possible methods to identify the mass hierarchy and acquire information about $\theta_{13}$ and neutrino masses by detecting supernova neutrinos. We apply these methods to some current neutrino experiments.Comment: 21 pages, 11 figure

Approximating the monomer-dimer constants through matrix permanent

The monomer-dimer model is fundamental in statistical mechanics. However, it is #P-complete in computation, even for two dimensional problems. A formulation in matrix permanent for the partition function of the monomer-dimer model is proposed in this paper, by transforming the number of all matchings of a bipartite graph into the number of perfect matchings of an extended bipartite graph, which can be given by a matrix permanent. Sequential importance sampling algorithm is applied to compute the permanents. For two-dimensional lattice with periodic condition, we obtain $0.6627\pm0.0002$, where the exact value is $h_2=0.662798972834$. For three-dimensional lattice with periodic condition, our numerical result is $0.7847\pm0.0014$, {which agrees with the best known bound $0.7653 \leq h_3 \leq 0.7862$.}Comment: 6 pages, 2 figure