A New Iterative Decoder of Space-Time Data in Time Selective MIMO Channels

In this paper we present a new iterative decoder of Space-Time Block Coded data in the presence of carrier offsets. This decoder starts the iteration with a small amount of training data to find the initial estimate of carrier offset, channel and noise co-variance. Subsequently it attempts to find the estimate of the STBC data by an alternating maximization (AM) technique. In this way better estimates of Space–Time data are achieved after the final iteration as compared to those found without an iterative method. Thus the new decoder reduces the training overhead required by the conventional data-aided (DA) estimators for efficient estimates of carrier offsets and S–T data, and provides higher data rate.     

Fluroscopy in paediatric fractures--setting a local diagnostic reference level

BACKGROUND: The ionizing radiations (Medical Exposure) Regulation 2000 has made it mandatory to establish diagnostic reference levels (DRLs) for all typical radiological examinations. OBJECTIVES: We attempt to provide dose data for some common fluoroscopic procedures used in orthopaedic trauma that may be used as the basis for setting DRLs for paediatric patients. MATERIALS AND METHODS: The dose area product (DAP) in 865 paediatric trauma examinations was analysed. Median DAP values and screening times for each procedure type along with quartile values for each range are presented. RESULTS: In the upper limb, elbow examinations had maximum exposure with a median DAP value of 1.21 cGy cm2. Median DAP values for forearm and wrist examinations were 0.708 and 0.538 cGy cm2, respectively. In lower limb, tibia and fibula examinations had a median DAP value of 3.23 cGy cm2 followed by ankle examinations with a median DAP of 3.10 cGy cm2. The rounded third quartile DAP value for each distribution can be used as a provisional DRL for the specific procedure type.     

An experimental study on the appraisal of the visual environment at offices in relation to colour temperature and illuminance

Colour temperature and illumination level have affected the subjective impressions at an office setting. 2000 lx was preferred to 500 lx for impressions of comfort, spaciousness, brightness and saturation evaluation. A 4000 K colour temperature was preferred to 2700 K for impressions of ‘comfort and spaciousness’, while 2700 K was suggested for ‘relaxation’ and ‘saturation evaluation’. Test results indicate that, task–background contrast is more important and shall be studied for ‘perceived brightness’ evaluation. Participants liked the ‘mixed colour temperature mood’, the remote control and the flexibility in the lighting system and the majority offered to use it at offices.     

Color‐emotion associations,designing color schemes for urban environment‐architectural settings

Color in urban design has become an important issue, each city may present different colors which help to define and describe its architectural features. In the study, color in urban design with architectural setting is studied, façade colors are analyzed with a specific emphasis on the following research questions; “Can color schemes be designed in respect to color‐emotion associations? ” and “Are color‐emotion associations affective while designing architectural setting‐urban environment?.” Non‐color experts, 170 people, from different European and non‐European countries were asked to match the most appropriate adjectives with the given street views in accordance to their color schemes. In the first step, the effect of color is identified in relation to architectural environment‐urban setting, second the relative effect of color is studied as a component of the material. A categorical specification on color cognition and linguistic level of representation is attempted. The results can be a starting point to highlight the importance of preparing color schemes in regard to color‐emotion associations. Abstract color schemes may also provide us an idea about image setting, especially at design process stage. In the study, keywords are linked as environment‐response pairs; such as quiet, calming, lively, exclusive, reserved, and natural. Human psychophysical structure such as “warm‐cool,” “heavy‐light” in regard to visualizing certain colors are evaluated and described in terms of building materials.     

An Interval-Based Scheduling Algorithm for Optical WDM Star Networks

Photonic Network Communications -     

Boolean AND and OR logic for cell signalling gateways: a communication perspective

Cell signalling plays a vital role in development, sustaining, differentiation, and reproduction of cells. Pathways involved in signalling networks are quite interwoven and complex. Complexity encountered in understanding these pathways is often reduced with the help of Boolean circuit representation. In this study, the authors provide communication aspect of the signalling pathways that have two input Boolean logic AND/OR implemented at the rear effector protein. Communication is assumed to be taking place in extracellular and intracellular environment. The two environments are connected using a receptor protein acting as relay between a molecular source and effector protein. Each relay detects molecules from outside environment and stimulates the production of signals in the intracellular space. These signals/molecules further activate the effector protein which acts as a Boolean switch driven by AND/OR logic. Assuming Poisson reception at the relay as well as at the receiver, the authors provide probability of error of the AND and OR Boolean logic communication systems. Furthermore, reliability and some capacity bounds are deduced for the given Boolean communication system.Inspec keywords: cellular biophysics, integrated circuit modelling, stochastic processes, probability, cellular transport, proteins, molecular biophysics, Boolean functions, biochemistryOther keywords: cell signalling, communication perspective, signalling networks, Boolean circuit representation, communication aspect, signalling pathways, input Boolean logic, rear effector protein, extracellular environment, intracellular environment, receptor protein, relay, stimulates, signals/molecules, Boolean switch, Boolean logic communication systems, given Boolean communication system     

Intelligent toolpath selection via multi-criteria optimization in complex sculptured surface milling

A new approach is presented the first time in the literature to generate multi-criteria optimized toolpaths for the complex sculptured surface machining. This is achieved by developing a mathematical solution that consists of the physical relationship between the mean resultant forces, cycle times and scallop heights. These three critical process outputs in machining are conflicting with each other. In other words, there are tradeoffs between cutting force magnitudes, cycle time and scallop height. This triple bounded problem in machining is solved in this article by using the objective weighting based algorithm. The multi-criteria toolpath optimization method introduced here for sculptured surface machining increases the controllability of the process with the specified criteria. The method also allows determining all pareto optimal solutions and all possible weights of each criteria. Moreover, the method eases to observe and analyze the trade-off between each criterion, facilitate the limitation and minimization of each criterion and determine corresponding toolpath for each solution. This solution produces optimized toolpaths according to preset constraints for mean cutting force, cycle time and scallop height. The method is a generalized solution for determining optimized toolpaths based on given constrains in free-form surface machining. In order to validate the multi-criteria toolpath optimization method, experiments at various conditions are performed on free-form machining and an example is presented in this article.     

Comparative Analysis of Algorithms Governing Spectrum Handoff in Cognitive Radio Networks

Wireless Personal Communications - Wireless Communication technology has completely adopted the dynamic spectrum access policy due to the prevailing issues of spectrum scarcity. Cognitive Radio...     

Affordable housing finance companies in India: how do they ‘differently’ serve the underserved?

Abstract

Over the years, the importance of access to affordable finance has inevitably been recognized as a critical component of developing the third world. Against the backdrop of huge under-penetration of the housing finance sector in India, this study reflects on the functioning of Affordable Housing Finance Companies (AHFCs), which are among the important stakeholders providing affordable housing loans to the low-income segment households. However, the process through which these new entrants have been able to down-market housing finance remains a black box till date. In light of this research gap, this study proposes a conceptual model that succinctly captures the business process of AHFCs across three main dimensions: Outreach Approach, Lending and Underwriting Practices and Risk Management Interventions. This model reflects on the kaleidoscope of process innovations that the AHFCs have embraced to cater to the housing finance needs of the low-income customers, while achieving profitability and social impact.     

Preference for accent and background colors in interior architecture in terms of similarity/contrast of natural color system attributes

Color combination criteria are said to entail an affective response in interior design. We investigated the color combination criteria that orient the preference of current observers, after Le Corbusier's 1931 Salubra keyboards. We explored the similarity/contrast in Natural Color System (NCS) hue, blackness, and chromaticness in 312 combinations with four colors, two backgrounds and two accent colors, coming from 43 individual colors, on the walls of a simulated interior of a bedroom from the Swiss Pavilion (Le Corbusier, 1930-1931). Participants were 644 students of architecture and interior design in Western Europe and Near East, who evaluated with a Likert scale their preference for virtual images via an online survey. Results indicate that the most preferred color combinations are those with hues closer in the color wheel, being the similarity between hues in the backgrounds more important than in the accent colors, and with NCS B30G to G as the most preferred hues. Observers preferred color compositions with blackness under 10% and similar blackness between the two background colors, together with a certain blackness contrast between these background colors and the two color accents. Similarly, observers liked color compositions with low chromaticness and low chromaticness difference among the four colors of the composition.