Spektralno-efikasna zelena bežična komunikacija pomoću kognitivnog UWB signalnog modela

This paper focuses on spectral lines suppression for non-coherent impulse-radio ultra-wideband (IR-UWB) signals in the presence of pulse attenuation and timing jitter. Particular attention is devoted to severely unbalanced (i.e. non-uniform distributed) data sources where a unified spectral analysis is considered for both uncorrelated and correlated M-ary biorthogonal data-stream scenarios. Indeed, the specific novelty insights of this paper are as follows: i) Proposal of a new spectral-efficient signal model as a modified version of transmitted-reference (TR) approach, where each transmitted symbol is represented by a preamble Data-based Statistical Reference (DSR) followed by a set of transmitted data pulses and within this context, the preamble signal is designed to eliminate spectral lines via an adaptive monitoring of data-stream statistics as the optimal spectral policy; ii) Performance analysis in order to derive optimal signal parameters; iii) Evaluation of the system capabilities over different predefined operational modes.Ovaj rad se fokusira na prigušenje spektralnih linija kod ne-koherentnih radio-impulsnih ultra-širokopojasnih (IR-UWB) signala prilikom slabljenja pulsa i vremenskog podrhtavanja. Posebna pažnja je pridana značajno neuravnoteženim (npr. ne-unifornmno distribuiranim) izvorima podataka gdje je jedinstvena spektralna analiza razmatrana za nekorelirane i korelirane M-arne biortogonalne scenarije prijenosa podataka. Novine predstavljene u ovom radu su: i) Novi spektralno-efikasni signalni model koji je modificirana verzija pristupa prijenosom-reference (TR), gdje se svaki preneseni simbol prikazuje pomoću preambule definirane statistikom reference podataka (DSR) koju slijedi skup prenesenih podatkovnih pulseva, te je u tom kontekstu preambula signala dizajnirana kako bi se eliminirale spektralne linije pomoću optimalnog spektralnog kriterija definiranog adaptivnim praćenjem statistike poslanih podataka; ii) Analiza performansi kako bi se dobili optimalni parametri signala i iii) Evaluacija sposobnosti sustava prilikom rada u različitim predefiniranim stanjima

Risk-Based Capacitor Placement in Distribution Networks

In this paper, the problem of sizing and placement of constant and switching capacitors in electrical distribution systems is modelled considering the load uncertainty. This model is formu- lated as a multicriteria mathematical problem. The risk of voltage violation is calculated, and the stability index is modelled using fuzzy logic and fuzzy equations. The instability risk is introduced as the deviation of our fuzzy-based stability index with respect to the stability margin. The capacitor placement objectives in our paper include: (i) minimizing investment and installation costs as well as loss cost; (ii) reducing the risk of voltage violation; and (iii) reducing the instability risk. The proposed mathematical model is solved using a multi-objective version of a genetic algorithm. The model is implemented on a distribution network, and the results of the experiment are discussed. The impacts of constant and switching capacitors are assessed separately and concurrently. Moreo- ver, the impact of uncertainty on the multi-objectives is determined based on a sensitivity analysis. It is demonstrated that the more the uncertainty is, the higher the system cost, the voltage risk and the instability risk are

Network traffic flow optimization under performance constraints

In this paper, a model-based perimeter control policy for large-scale urban vehicular networks is proposed. Assuming a homogeneously loaded vehicle network and the existence of a well-posed Network Fundamental Diagram (NFD), we describe a protected network throughout its aggregated dynamics including nonlinear exit flow characteristics. Within this framework of constrained optimal boundary flow gating, two main performance metrics are considered: (a) first, connected to the NFD, the concept of average network travel time and delay as a performance metric is defined; (b) second, at boundaries, we take into account additional external network queue dynamics governed by uncontrolled inflow demands. External queue capacities in terms of finite-link lengths are used as the second performance metric. Hence, the corresponding performance requirement is an upper bound of external queues. While external queues represent vehicles waiting to enter the protected network, internal queue describes the protected network’s aggregated behavior. By controlling the number of vehicles joining the internal queue from the external ones, herewith a network traffic flow maximization solution subject to the internal and external dynamics and their performance constraints is developed. The originally non-convex optimization problem is transformed to a numerically efficiently convex one by relaxing the performance constraints into time-dependent state boundaries. The control solution can be interpreted as a mechanism which transforms the unknown arrival process governing the number of vehicles entering the network to a regulated process, such that prescribed performance requirements on travel time in the network and upper bound on the external queue are satisfied. Comparative numerical simulation studies on a microscopic traffic simulator are carried out to show the benefits of the proposed method

Assimilation of Freeze - Thaw Observations into the NASA Catchment Land Surface Model

The land surface freeze-thaw (F-T) state plays a key role in the hydrological and carbon cycles and thus affects water and energy exchanges and vegetation productivity at the land surface. In this study, we developed an F-T assimilation algorithm for the NASA Goddard Earth Observing System, version 5 (GEOS-5) modeling and assimilation framework. The algorithm includes a newly developed observation operator that diagnoses the landscape F-T state in the GEOS-5 Catchment land surface model. The F-T analysis is a rule-based approach that adjusts Catchment model state variables in response to binary F-T observations, while also considering forecast and observation errors. A regional observing system simulation experiment was conducted using synthetically generated F-T observations. The assimilation of perfect (error-free) F-T observations reduced the root-mean-square errors (RMSE) of surface temperature and soil temperature by 0.206 C and 0.061 C, respectively, when compared to model estimates (equivalent to a relative RMSE reduction of 6.7 percent and 3.1 percent, respectively). For a maximum classification error (CEmax) of 10 percent in the synthetic F-T observations, the F-T assimilation reduced the RMSE of surface temperature and soil temperature by 0.178 C and 0.036 C, respectively. For CEmax=20 percent, the F-T assimilation still reduces the RMSE of model surface temperature estimates by 0.149 C but yields no improvement over the model soil temperature estimates. The F-T assimilation scheme is being developed to exploit planned operational F-T products from the NASA Soil Moisture Active Passive (SMAP) mission

Indicators Affecting the Urban Resilience with a Scenario Approach in Tehran Metropolis

Urban resilience refers to the capacity of an urban system to fully recover from unforeseen calamities. This study aims to assess the physical resilience indicators used to measure urban resilience in Tehran, the political and economic capital of Iran, and to pinpoint the most significant direct and indirect influences on urban resilience. The research process divided into two parts. The environmental scanning approach (reviewing papers and published sources, interviewing specialists, and monitoring conferences) and the literature review were employed in the first part to compile a database of the key information on the elements impacting physical resilience. The most significant factors impacting physical resilience over the next ten years were requested to be identified by specialists and intellectuals in the second part. Finally, the MicMac program was used to analyze the data after 29 variables were specified in Delphi. In light of the trace-analysis-dependence diagram, which depicts the instability of the influential factors and the persistence of their impact on other variables, the results demonstrate that Tehran’s physical resilience is in an unstable condition. According to the results, the factors that have the maximum impact on other variables are granularity drivers, emergency evacuation capacity, rescue and security spaces (emergency, fire station, and police station), impermeability, rate of the amendment and retrofitting measures in the buildings of each zone, building age, and the compatibility of land uses. The variables that are most susceptible to change from other variables include the distribution status of dangerous land uses, the quality of the buildings, the rate of historically vulnerable buildings, the vulnerability of internal and external roads, the rate of improvements and retrofitting measures in buildings in each zone, as well as historically vulnerable historical buildings

Estimation of genetic parameters for body weight at different ages in Mehraban sheep

The objective of the present study is to estimate genetic parameters of birth weight (BW, n = 3005), weaning weight (WW, n = 2800), 6 months weight (6 MW, n = 2600), 9 months weight (9 MW, n = 1990) and yearling weight (YW, n = 1450) of Mehraban sheep, collected during 1995 - 2007 at Mehraban sheep Breeding Station in Hamedan province, Iran. (Co)variance components and genetic parameters were estimated with univariate and multivariate animal model using restricted maximum likelihood (REML) procedure. Effect of herd, lamb's sex, and year of birth were significant on all traits (P < 0.05). The estimates of direct heritability for BW, WW, 6MW, 9MW and YW were 0.30±0.05, 0.30±0.04, 0.35±0.05, 0.37±0.04 and 0.43±0.04 respectively. Maternal heritability estimates for mentioned traits were 0.17±0.03, 0.18±0.03, 0.14±0.03, 0.12±0.03 and 0.10±0.02, respectively. The estimates of the direct genetic correlation between BW-WW, BW-6MW, BW-9MW, BW-YW, WW-6MW, WW-9MW, WW-YW, 6MW-9MW, 6MW-YW and 9MW-YW were 0.287±0.09, 0.305±0.09, 0.249±0.03, 0.136±0.07, 0.825±0.34, 0.713±0.05, 0.845±0.52, 0.862±0.06, 0.596±0.09 and 0.712±0.02 respectively. The estimates of the phenotypic correlation between traits were positive and ranged from 0.152 for BW-9MW to 0.835 for 9MW-YW.Key words: Mehraban sheep, heritability, genetic correlation, body weight traits

Ultrasound Imaging of Gene Expression in Mammalian Cells

The study of cellular processes occurring inside intact organisms requires methods to visualize cellular functions such as gene expression in deep tissues. Ultrasound is a widely used biomedical technology enabling noninvasive imaging with high spatial and temporal resolution. However, no genetically encoded molecular reporters are available to connect ultrasound contrast to gene expression in mammalian cells. To address this limitation, we introduce mammalian acoustic reporter genes. Starting with a gene cluster derived from bacteria, we engineered a eukaryotic genetic program whose introduction into mammalian cells results in the expression of intracellular air-filled protein nanostructures called gas vesicles, which produce ultrasound contrast. Mammalian acoustic reporter genes allow cells to be visualized at volumetric densities below 0.5% and permit high-resolution imaging of gene expression in living animals

Assimilation of Freeze–Thaw Observations into the NASA Catchment Land Surface Model

The land surface freeze–thaw (F/T) state plays a key role in the hydrological and carbon cycles and thus affects water and energy exchanges and vegetation productivity at the land surface. In this study, an F/T assimilation algorithm was developed for the NASA Goddard Earth Observing System, version 5 (GEOS-5), modeling and assimilation framework. The algorithm includes a newly developed observation operator that diagnoses the landscape F/T state in the GEOS-5 Catchment land surface model. The F/T analysis is a rule-based approach that adjusts Catchment model state variables in response to binary F/T observations, while also considering forecast and observation errors. A regional observing system simulation experiment was conducted using synthetically generated F/T observations. The assimilation of perfect (error free) F/T observations reduced the root-mean-square errors (RMSEs) of surface temperature and soil temperature by 0.206° and 0.061°C, respectively, when compared to model estimates (equivalent to a relative RMSE reduction of 6.7% and 3.1%, respectively). For a maximum classification error CEmax of 10% in the synthetic F/T observations, the F/T assimilation reduced the RMSE of surface temperature and soil temperature by 0.178° and 0.036°C, respectively. For CEmax = 20%, the F/T assimilation still reduces the RMSE of model surface temperature estimates by 0.149°C but yields no improvement over the model soil temperature estimates. The F/T assimilation scheme is being developed to exploit planned F/T products from the NASA Soil Moisture Active Passive (SMAP) mission

Report of an unusual cause of rhinolithiasis: An 'opioma'

We report an unusual case of unilateral rhinolith. The patient was a 21-year-old man who had a history of left-sided nasal obstruction and recurrent bouts of fetid, purulent rhinorrhea of several years' duration. The rhinolith, which had formed around an impacted foreign body, was extracted in several pieces under local anesthesia. Laboratory evaluation revealed that the foreign body was a hardened mixture of codeine and opium wrapped in a small sheet of nylon - what we called an "opioma."

Can Activated Titanium Interbody Cages Accelerate or Enhance Spinal Fusion? A Review of the Literature and a Design for Clinical Trials

While spinal interbody cage options have proliferated in the past decade, relatively little work has been done to explore the comparative potential of biomaterial technologies in promoting stable fusion. Innovations such as micro-etching and nano-architectural designs have shown purported benefits in in vitro studies, but lack clinical data describing their optimal implementation. Here, we critically assess the pre-clinical data supportive of various commercially available interbody cage biomaterial, topographical, and structural designs. We describe in detail the osteointegrative and osteoconductive benefits conferred by these modifications with a focus on polyetheretherketone (PEEK) and titanium (Ti) interbody implants. Further, we describe the rationale and design for two randomized controlled trials, which aim to address the paucity of clinical data available by comparing interbody fusion outcomes between either PEEK or activated Ti lumbar interbody cages. Utilizing dual-energy computed tomography (DECT), these studies will evaluate the relative implant-bone integration and fusion rates achieved by either micro-etched Ti or standard PEEK interbody devices. Taken together, greater understanding of the relative osseointegration profile at the implant-bone interface of cages with distinct topographies will be crucial in guiding the rational design of further studies and innovations