Fuzzy intensification operator based contrast enhancement in the compressed domain

With the increasing sizes of high resolution images, their storage and processing directly in the compressed domain has significantly gained importance. Algorithms for compressed domain image processing provide a powerful computational alternative to classical (pixel level) based implementations. While linear algorithms can be applied straightforward to the JPEG compressed images, this is not the case for nonlinear image processing, as for example contrast enhancement algorithms. In this paper a new implementation in the compressed domain of a very efficient contrast enhancement, based on fuzzy set modeling and on a fuzzy intensification operator, is presented. The fuzzy set parameters are adaptively chosen by analyzing the statistics of the image data in the compressed domain, in order to optimally enhance the image contrast. The nonlinear enhancement procedure requires a grey level threshold, for which an adaptive implementation, taking into account the frequency content of each coefficient block in the DCT (Discrete Cosine Transform) encoded JPEG image is proposed. This guarantees the optimal quality at minimum computational cost. The experimental results for a set of various contrast images validate the good performance and functionality of the proposed implementation.     

The ‘Urban Elements’ method for teaching parametric urban design to professionals

The article proposes a method for teaching advanced urban design to working professionals in Singapore. The article aims to expand the discourse on parametric urban design education by introducing ‘Urban Elements’ as conceptual urban design instruments with an inherent rule-based logic, which can help to bridge gaps in teaching parametric urban design thinking. As case study we present a course developed for and delivered to the Urban Redevelopment Authority (URA) in Singapore in 2017 by the Future Cities Laboratory at the Singapore-ETH Centre. The article reports on the pedagogical method, course results and course feedback. The main difficulties of teaching professionals in parametric urban design are described and possible reasons and improvements are discussed. The results show that participants using the ‘Urban Elements’ method successfully linked theoretical input to urban design problems, applied evidence-based urban design strategies to these problems, and developed parametric definitions to explore the solution spaces of these urban design challenges. The teaching methodology presented opens up a new research field for urban design pedagogy at the intersection of explicating urban design intent, integrating multidisciplinary knowledge and exploring new software driven tools.     

Signatures of Superfluidity in Dilute Fermi Gases near a Feshbach Resonance

No Heading We present a brief account of the most salient properties of vortices in dilute atomic Fermi superfluids near a Feshbach resonance.PACS numbers: 03.75.Ss     

Proactive cooperative scheduling and buffer management for multimedia networks

Is it possible, and to what extent feasible, for link schedulers and buffer managers in multimedia networks with propagation delays to relieve effectively congestion by means of feedback signaling? We show that a proactive cooperative control algorithm for distributed resource scheduling and buffer management obviates the problem of propagation delays. The algorithm is based on traffic predictions of correlated input traffic streams into network nodes. Nodes projecting to be under stress signal their neighboring upstream nodes for the latter to readjust their flow rates, whileguaranteeing quality of service as negotiated at call setup. Detailed implementations of the adaptive, feedback control mechanisms of distributed asynchronous algorithms that project future overload conditions are presented. The design allows the underlying single-node link scheduling and buffer management algorithm to be run in either a cooperative or a noncooperative mode of operation.     

Realization of a multichannel integrated Young interferometer chemical sensor

We report on the design, realization, and characterization of a four-channel integrated optical Young interferometer device that enables simultaneous and independent monitoring of three binding processes. The generated interference pattern is recorded by a CCD camera and analyzed with a fast-Fourier-transform algorithm. We present a thorough theoretical analysis of such a device. The realized device is tested by monitoring glucose solutions that induce well defined phase changes between output channels. The simultaneous measurement of three different glucose concentrations shows the multipurpose feature of such devices. The observed errors, caused by the mismatching of spatial frequencies of individual interference patterns with those determined from the CCD camera, are reduced with different reduction schemes. The phase resolution for different pairs of channels was approximately 1 x 10(-4) fringes, which corresponds to a refractive-index resolution of approximately 8.5 x 10(-8). The measured sensitivity coefficient of the phase change versus refractive-index change of approximately 1.22 x 10(3) x 2pi agrees well with the calculated coefficient of approximately 1.20 x 10(3) x 2pi.