Cities as emergent models: the morphological logic of Manhattan and Barcelona

This paper is set to unveil several particulars about the logic embedded in the diachronic model of city growth and the rules which govern the emergence of urban spaces. The paper outlines an attempt to detect and define the generative rules of a growing urban structure by means of evaluation techniques. The initial approach in this regards will be to study the evolution of existing urban regions or cities which in our case are Manhattan and Barcelona and investigate the rules and causes of their emergence and growth. The paper will concentrate on the spatial aspect of the generative rules and investigate their behaviour and dimensionality. Several Space Syntax evaluation methods will be implemented to capture the change of spatial configurations within the growing urban structures. In addition, certain spatial elements will be isolated and tested aiming to illustrate their influence on the main spatial structures. Both urban regions were found to be emergent products of a bottom up organic growth mostly distinguished in the vicinities of the first settlements. Despite the imposition of a uniform grid on both cities in later stages of their development these cities managed to deform the regularity in the preplanned grid in an emergent manner to end up with an efficient model embodied in their current spatial arrangement. The paper reveals several consistencies in the spatial morphology of both urban regions and provides explanation of these regularities in an approach to extract the underlying rules which contributed to the growth optimization process

Quantum Information at the Interface of Light with Atomic Ensembles and Micromechanical Oscillators

This article reviews recent research towards a universal light-matter interface. Such an interface is an important prerequisite for long distance quantum communication, entanglement assisted sensing and measurement, as well as for scalable photonic quantum computation. We review the developments in light-matter interfaces based on room temperature atomic vapors interacting with propagating pulses via the Faraday effect. This interaction has long been used as a tool for quantum nondemolition detections of atomic spins via light. It was discovered recently that this type of light-matter interaction can actually be tuned to realize more general dynamics, enabling better performance of the light-matter interface as well as rendering tasks possible, which were before thought to be impractical. This includes the realization of improved entanglement assisted and backaction evading magnetometry approaching the Quantum Cramer-Rao limit, quantum memory for squeezed states of light and the dissipative generation of entanglement. A separate, but related, experiment on entanglement assisted cold atom clock showing the Heisenberg scaling of precision is described. We also review a possible interface between collective atomic spins with nano- or micromechanical oscillators, providing a link between atomic and solid state physics approaches towards quantum information processing

Vortex lattices in the lowest Landau level for confined Bose-Einstein condensates

We present the results of numerical calculations of the groundstates of weakly-interacting Bose-Einstein condensates containing large numbers of vortices. Our calculations show that these groundstates appear to be close to uniform triangular vortex lattices. However, slight deviations from a uniform triangular lattice have dramatic consequences on the overall particle distribution. In particular, we demonstrate that the overall particle distribution averaged on a lengthscale large compared to the vortex lattice constant is well approximated by a Thomas-Fermi profile.Comment: 5 pages, 4 figure

On a Kelvin-Voigt Viscoelastic Wave Equation with Strong Delay

An initial-boundary value problem for a viscoelastic wave equation subject to a strong time-localized delay in a Kelvin & Voigt-type material law is considered. Transforming the equation to an abstract Cauchy problem on the extended phase space, a global well-posedness theory is established using the operator semigroup theory both in Sobolev-valued $C^{0}$- and BV-spaces. Under appropriate assumptions on the coefficients, a global exponential decay rate is obtained and the stability region in the parameter space is further explored using the Lyapunov's indirect method. The singular limit $\tau \to 0$ is further studied with the aid of the energy method. Finally, a numerical example from a real-world application in biomechanics is presented.Comment: 34 pages, 4 figures, 1 set of Matlab code

Reduction of the phase jitter in differential phase-shift-keying soliton transmission systems by in-line Butterworth filters

We examine reduction of phase jitter by use of in-line Butterworth filters in soliton systems in the context of differential phase-shift-keying coding. We also demonstrate numerically that the use of a Butterworth filter in a return-to-zero differential phase-shift-keying system can reduce continuum background radiation

Serangga Perusak Kecipir (Psophocarpus Tetragonolobus L.)

Kecipir kini merupakan tanaman protein yang mulai digalakkan pengembangannya karena kandungan protein yang hampir sama dengan kedelai. Biji kering mengandung 2.9,8 - 37,4% protein, daun 5,7 - 15%, bunga sekitar 5,6% dan polong muda 1,9 - 2,9% (NAS 1975, Citroreksoko 1977). Banyak bagian tanaman kecipir, seperti daun muda, polong dan biji, serta pada beberapa vaiietas juga juga umbinya, dapat dimakan (Burkill 1936).Penggalakan pengembangan budidaya kecipii ini memerlukan perhatian masalah hamanya. Penelitian mengenai hama kecipir telah dilakukan di berbagai negara, di antaranya ialah Papua Niugini, Malaysia dan Filipina (Price 1978). Di Indonesia sendiri penelaahan terhadap hama kecipir masih agak diabaikan. Dari pengumpulan data yang telah dilakukan temyata bahwa kecipir di Indonesia mempunyai pula musuh alami yang berpotensi dan kalau dibiarkan dapat menggagalkan USAha penanamannya (Adisoemarto dkk. 1978). Mengingat permasalahan hama yang timbul perlu dilakukan penelaahan secara kualitatif serangga hama yang berhubungan dengan kecipir

Radio-frequency dressing of multiple Feshbach resonances

We demonstrate and theoretically analyze the dressing of several proximate Feshbach resonances in Rb-87 using radio-frequency (rf) radiation. We present accurate measurements and characterizations of the resonances, and the dramatic changes in scattering properties that can arise through the rf dressing. Our scattering theory analysis yields quantitative agreement with the experimental data. We also present a simple interpretation of our results in terms of rf-coupled bound states interacting with the collision threshold.Comment: 4+ pages, 3 figures, 1 table; revised introduction & references to reflect published versio

Simulations of a Scintillator Compton Gamma Imager for Safety and Security

We are designing an all-scintillator Compton gamma imager for use in security investigations and remediation actions involving radioactive threat material. To satisfy requirements for a rugged and portable instrument, we have chosen solid scintillator for the active volumes of both the scatter and absorber detectors. Using the BEAMnrc/EGSnrc Monte Carlo simulation package, we have constructed models using four different materials for the scatter detector: LaBr_3, NaI, CaF_2 and PVT. We have compared the detector performances using angular resolution, efficiency, and image resolution. We find that while PVT provides worse performance than that of the detectors based entirely on inorganic scintillators, all of the materials investigated for the scatter detector have the potential to provide performance adequate for our purposes.Comment: Revised text and figures, Presented at SORMA West 2008, Published in IEEE Transactions on Nuclear Scienc

Characterising Place by Scene Depth

Turner and Penn introduced the notion of integration of isovist fields as a means to understand such fields syntactically - as a set of components with a structural relationship to a global whole (1999). This research was further refined to put forward the concept of visibility graph analysis (VGA) as a tool for architectural analysis (Turner, Doxa, O’sullivan, & Penn, 2001), which has become widely used. We suggest a complementary method of characterising place that does not make use of integration or a graph yet which allows - as visibility graph analysis does - discrete view points to be dimensioned in relation to a set of such viewpoints. In our method, Principal Component Analysis (PCA), a statistical technique, is employed to infer salient characteristics of a set of views and then to situate these component views within a low dimensional space in order to compare the extent to which each view corresponds to these characteristics. We demonstrate the method by reference to two distinct urban areas with differing spatial characteristics. Because PCA operates on vectors, order of the data has important implications. We consider some of these implications including view orientation and chirality (handedness) and assess the variance of results with regard to these factors