An economic assessment of STOL aircraft potential including terminal area environmental considerations, volume 1

The results of an economic and environmental study of short haul airline systems using short takeoff and landing (STOL) aircraft are presented. The STOL system characteristics were optimized for maximum patronage at a specified return on investment, while maintaining noise impact compatibility with the terminal area. Supporting studies of aircraft air pollution and hub airport congestion relief were also performed. The STOL concept specified for this study was an Augmentor Wing turbofan aircraft having a field length capability of 2,000 ft. and an effective perceived noise level of 95 EPNdB at 500 ft. sideline distance. An economic and environmental assessment of the defined STOL system and a summary of the methodology, STOL system characteristics and arena characteristics are provided

Control of lasing in fully chaotic open microcavities by tailoring the shape factor

We demonstrate experimentally that lasing in a semiconductor microstadium can be optimized by controlling its shape. Under spatially uniform optical pumping, the first lasing mode in a GaAs microstadium with large major-to-minor-axis ratio usually corresponds to a high-quality scar mode consisting of several unstable periodic orbits. Interference of waves propagating along the constituent orbits may minimize light leakage at particular major-to-minor-axis ratio. By making stadium of the optimum shape, we are able to maximize the mode quality factor and align the mode frequency to the peak of the gain spectrum, thus minimizing the lasing threshold. This work opens the door to control chaotic microcavity lasers by tailoring the shape factor

Does the Informal Sector Thrive Under Democracy or Autocracy?: The Case of Nepal

Our paper investigates the size and development of the informal sector in Nepal using aggregate data over the period 1991 to 2009. Our estimation using the Multiple Indicator Multiple Cause (MIMIC) model shows that the average size of the informal sector has been about 44%. Nepal has been classified as having a hybrid political regime, so we show the effect that autocracy and democracy has had on the growth of the informal sector. Our results shows that a high degree of autocracy reduced the size of the informal sector by about 2% while greater direct democracy reduced the informal sector by about 10%

Using handheld pocket computers in a wireless telemedicine system

Objectives: To see if senior emergency nurse practitioners can provide support to inexperienced ones in a Minor Injuries Unit by using a wireless LAN system of telemedicine transmitting images to a PDA when they were on duty. In addition, whether such a system could be sufficiently accurate to make clinical diagnoses with a high level of diagnostic confidence. This would permit an overall lower grade of nurse to be employed to manage most of the cases as they arrive with a proportionate lowering of costs. Methods: The wireless LAN equipment could roam in the Minor Injuries Unit and the experienced emergency Nurse practitioners could be at home, shopping or even at a considerable distance from the centre. Thirty pictorial images of patients who had been sent to the Review Clinic were transmitted to a PDA various distances of one to sixteen miles from the centre. Two senior emergency nurse practitioners viewed the images and opined on the diagnosis, their degree of confidence in the diagnosis and their opinion of the quality of the image. Results: the images of patients were sharp, clear, and of diagnostic quality. The image quality was only uncertain, as was the level of confidence of the diagnosis if the patient was very dark skinned. Conclusions: The wireless LAN system works with a remote PDA in this clinical situation. However there are question marks over the availability of enough experienced emergency nurse practitioners to staff a service that provides senior cover for longer parts of the day and at weekends

Complete controllability of finite-level quantum systems

Complete controllability is a fundamental issue in the field of control of quantum systems, not least because of its implications for dynamical realizability of the kinematical bounds on the optimization of observables. In this paper we investigate the question of complete controllability for finite-level quantum systems subject to a single control field, for which the interaction is of dipole form. Sufficient criteria for complete controllability of a wide range of finite-level quantum systems are established and the question of limits of complete controllability is addressed. Finally, the results are applied to give a classification of complete controllability for four-level systems.Comment: 14 pages, IoP-LaTe

Spatial Coherence of a Polariton Condensate

We perform Young's double-slit experiment to study the spatial coherence properties of a two-dimensional dynamic condensate of semiconductor microcavity polaritons. The coherence length of the system is measured as a function of the pump rate, which confirms a spontaneous buildup of macroscopic coherence in the condensed phase. An independent measurement reveals that the position and momentum uncertainty product of the condensate is close to the Heisenberg limit. An experimental realization of such a minimum uncertainty wave packet of the polariton condensate opens a door to coherent matter-wave phenomena such as Josephson oscillation, superfluidity, and solitons in solid state condensate systems

A Portrait of firm Expansion and Contraction Channels

We present a novel set of stylised facts on forms of firm expansion and contraction, using unique business register data for the United Kingdom between 1997 and 2005. We distinguish between adjustments of employment and turnover at existing establishments, expansions and contractions taking place via greenfield investments and disinvestments, and via acquisitions and sell-offs. We document the relative importance of these three channels and how firms choose between them. We interpret our findings in the light of existing theories of firm dynamics, and propose directions for future theoretical developments

Coherent pairing states for the Hubbard model

We consider the Hubbard model and its extensions on bipartite lattices. We define a dynamical group based on the $\eta$-pairing operators introduced by C.N.Yang, and define coherent pairing states, which are combinations of eigenfunctions of $\eta$-operators. These states permit exact calculations of numerous physical properties of the system, including energy, various fluctuations and correlation functions, including pairing ODLRO to all orders. This approach is complementary to BCS, in that these are superconducting coherent states associated with the exact model, although they are not eigenstates of the Hamiltonian.Comment: 5 pages, RevTe