Two-dimensional heterogeneous photonic bandedge laser

We proposed and realized a two-dimensional (2D) photonic bandedge laser surrounded by the photonic bandgap. The heterogeneous photonic crystal structure consists of two triangular lattices of the same lattice constant with different air hole radii. The photonic crystal laser was realized by room-temperature optical pumping of air-bridge slabs of InGaAsP quantum wells emitting at 1.55 micrometer. The lasing mode was identified from its spectral positions and polarization directions. A low threshold incident pump power of 0.24mW was achieved. The measured characteristics of the photonic crystal lasers closely agree with the results of real space and Fourier space calculations based on the finite-difference time-domain method.Comment: 14 pages, 4 figure

Enhancing quantum entanglement for continuous variables by a coherent superposition of photon subtraction and addition

We investigate how the entanglement properties of a two-mode state can be improved by performing a coherent superposition operation of photon subtraction and addition, proposed by Lee and Nha [Phys. Rev. A 82, 053812 (2010)], on each mode. We show that the degree of entanglement, the EPR-type correlation, and the performance of quantum teleportation can be all enhanced for the output state when the coherent operation is applied to a two-mode squeezed state. The effects of the coherent operation are more prominent than those of the mere photon subtraction and the addition particularly in the small squeezing regime, whereas the optimal operation becomes the photon subtraction in the large-squeezing regime.Comment: 6 pages, 6 figures, published versio

A photonic-crystal optical antenna for extremely large local-field enhancement

We propose a novel design of an all-dielectric optical antenna based on photonic-band-gap confinement. Specifically, we have engineered the photonic-crystal dipole mode to have broad spectral response (Q ~70) and well-directed vertical-radiation by introducing a plane mirror below the cavity. Considerably large local electric-field intensity enhancement ~4,500 is expected from the proposed design for a normally incident planewave. Furthermore, an analytic model developed based on coupled-mode theory predicts that the electric-field intensity enhancement can easily be over 100,000 by employing reasonably high-Q (~10,000) resonators

A Representation Framework of Product- Service Systems for Classification & Design

Abstract A Product-Service System (PSS) is a system of products, services, supporting networks and infrastructure that is designed to satisfy customer needs and to provide values. PSSs are very different from each other while some PSSs are similar to some. A representation framework of PSSs has been devised so that various PSSs could be represented and compared using the framework composed of twelve spaces, or viewpoints. Also the framework could serve as a design guide so that those issues from the viewpoints of the specific spaces of the representation framework could be considered in designing PSSs. The framework is composed of spaces such as value, product, service, product-service ratio, customer, business model, actor, touchpoint, context, time, society, and environment. In this short paper, the framework and its spaces are described using examples represented in the PSS Representation and Repository system, which is being developed to support manufacturing servitization

Electronic Commerce Strategy for Small and Medium Enterprises: Case Studies of Korean Firms

Business firms are increasingly taking part in online business activities through internet as the size of the e-commerce market is rapidly growing in the recent years. Electronic commerce (EC) activities now become an essential part of the business strategy for survival as well as growth for both large enterprises and small- to medium-sized enterprises (SMEs). Previous studies on e-commerce mostly focused on the adoption of EC by business firms, and also have been carried out with the data from big enterprises. More often than not, the results obtained from the large business firms are used to provide the guidelines for small to medium-sized enterprises (SMEs). SMEs are, however, different from large business firms in many aspects, and need to be studied on their own. This paper extends the previous research on EC in two aspects. Firstly, we study the e-commerce issues in the area of implementation in relation to the business firm\u27s performance, beyond the adoption and diffusion of IT technology which has been the research issues in many previous research. Secondly, we focus on small and medium enterprises which comprise a large portion of national economy with significant influenc

Method of Extracting Is-A and Part-Of Relations Using Pattern Pairs in Mass Corpus

PACLIC 23 / City University of Hong Kong / 3-5 December 200

The Feasibility of Multidimensional CFD Applied to Calandria System in the Moderator of CANDU-6 PHWR Using Commercial and Open-Source Codes

The moderator system of CANDU, a prototype of PHWR (pressurized heavy-water reactor), has been modeled in multidimension for the computation based on CFD (computational fluid dynamics) technique. Three CFD codes are tested in modeled hydrothermal systems of heavy-water reactors. Commercial codes, COMSOL Multiphysics and ANSYS-CFX with OpenFOAM, an open-source code, are introduced for the various simplified and practical problems. All the implemented computational codes are tested for a benchmark problem of STERN laboratory experiment with a precise modeling of tubes, compared with each other as well as the measured data and a porous model based on the experimental correlation of pressure drop. Also the effect of turbulence model is discussed for these low Reynolds number flows. As a result, they are shown to be successful for the analysis of three-dimensional numerical models related to the calandria system of CANDU reactors

Reprogramming Audio-driven Talking Face Synthesis into Text-driven

In this paper, we propose a method to reprogram pre-trained audio-driven talking face synthesis models to be able to operate with text inputs. As the audio-driven talking face synthesis model takes speech audio as inputs, in order to generate a talking avatar with the desired speech content, speech recording needs to be performed in advance. However, this is burdensome to record audio for every video to be generated. In order to alleviate this problem, we propose a novel method that embeds input text into the learned audio latent space of the pre-trained audio-driven model. To this end, we design a Text-to-Audio Embedding Module (TAEM) which is guided to learn to map a given text input to the audio latent features. Moreover, to model the speaker characteristics lying in the audio features, we propose to inject visual speaker embedding into the TAEM, which is obtained from a single face image. After training, we can synthesize talking face videos with either text or speech audio