Single-mode propagation of light in one-dimensional all-dielectric light-guiding systems

Numerical results are presented for single-mode guidance, which is based on photonic band gap (PBG) effect, in one-dimensional planar all-dielectric light-guiding systems. In such systems there may be two kinds of light-speed point (the intersection of a mode-dispersion curve and the light line of guiding region ambient medium): one is the intrinsic light-speed point that is independent of the guiding region width, and the other is the movable light-speed point that varies with the guiding region width. It is found that the intrinsic light-speed point plays an important role to form the single-mode regime by destroying the coexistence of the lowest guided TM and TE modes that are born with a degeneration point. A sufficient and necessary condition for intrinsic light-speed points is given. The transverse resonance condition is derived in the Maxwell optics frame, and it is shown that there is a significant revision to the traditional one in the ray optics model. A mode-lost phenomenon is exposed and this phenomenon suggests a way of how to identify PBG-guided fundamental modes. Quasi-cutoff-free index-guided modes in the PBG guiding structures, which appear when the higher-index layers are adjacent to the guiding region and the guiding region width is small, are exposed and analyzed as well.Comment: 13 pages, 8 figures, 32 reference

A new navigation paradigm for virtual reality: the guided visit through a virtual world

The three main navigation paradigms for virtual worlds, i.e., free navigation, automatic tours, and multiuser navigation show important limitations when dealing with guided visits that involve interactive cooperation among several users in 3D virtual worlds over the Internet. In this paper, we present our research into this issue and some important results. We propose a new navigation paradigm denominated guided visit through a virtual world, where the capacity of a user guiding several remote users through the virtual world is enriched with the capacity to dynamically interchange the role of guiding between the connected users. The user that acts as a guide moves freely through the virtual world, and his/her movements are reproduced by the browsers of the other guided users. We also present the architecture and the system we developed that implements this paradigm, as well as its integration in a working realworld application that demonstrates its use

A conceptual framework for interactive virtual storytelling

This paper presents a framework of an interactive storytelling system. It can integrate five components: management centre, evaluation centre, intelligent virtual agent, intelligent virtual environment, and users, making possible interactive solutions where the communication among these components is conducted in a rational and intelligent way. Environment plays an important role in providing heuristic information for agents through communicating with the management centre. The main idea is based on the principle of heuristic guiding of the behaviour of intelligent agents for guaranteeing the unexpectedness and consistent themes

"Pudding mold" band drives large thermopower in Nax_xCoO2_2

In the present study, we pin down the origin of the coexistence of the large thermopower and the large conductivity in Na$_x$CoO$_2$. It is revealed that not just the density of states (DOS), the effective mass, nor the band width, but the peculiar {\it shape} of the $a_{1g}$ band referred to as the "pudding mold" type, which consists of a dispersive portion and a somewhat flat portion, is playing an important role in this phenomenon. The present study provides a new guiding principle for designing good thermoelectric materials.Comment: 5 page

Fiduciary Principles and the Jury

This Essay argues that because jurors exercise state power with wide discretion over the legal and practical interests of other citizens, and because citizens repose trust and remain vulnerable to jury and juror decisions, juries and jurors share important similarities with traditional fiduciary actors such as doctors, lawyers, and corporate directors and boards. The paradigmatic fiduciary duties – those of loyalty and care – therefore provide useful benchmarks for evaluating and guiding jurors in their decision-making role. A sui generis public fiduciary duty of deliberative engagement also has applications in considering the obligations of jurors. This framework confirms much of what we know about the jury’s form of political representation and also recommends some practical directions for jury reform

Imaging features of rare mesenychmal liver tumours: beyond haemangiomas.

Tumours arising from mesenchymal tissue components such as vascular, fibrous and adipose tissue can manifest in the liver. Although histopathology is often necessary for definitive diagnosis, many of these lesions exhibit characteristic imaging features. The radiologist plays an important role in suggesting the diagnosis, which can direct appropriate immunohistochemical staining at histology. The aim of this review is to present clinical and imaging findings of a spectrum of mesenchymal liver tumours such as haemangioma, epithelioid haemangioendothelioma, lipoma, PEComa, angiosarcoma, inflammatory myofibroblastic tumour, solitary fibrous tumour, leiomyoma, leiomyosarcoma, Kaposi sarcoma, mesenchymal hamartoma, undifferentiated embryonal sarcoma, rhabdomyosarcoma and hepatic metastases. Knowledge of the characteristic features of these tumours will aid in guiding the radiologic diagnosis and appropriate patient management