Spectral Analysis of Multi-dimensional Self-similar Markov Processes

In this paper we consider a discrete scale invariant (DSI) process $\{X(t), t\in {\bf R^+}\}$ with scale $l>1$. We consider to have some fix number of observations in every scale, say $T$, and to get our samples at discrete points $\alpha^k, k\in {\bf W}$ where $\alpha$ is obtained by the equality $l=\alpha^T$ and ${\bf W}=\{0, 1,...\}$. So we provide a discrete time scale invariant (DT-SI) process $X(\cdot)$ with parameter space $\{\alpha^k, k\in {\bf W}\}$. We find the spectral representation of the covariance function of such DT-SI process. By providing harmonic like representation of multi-dimensional self-similar processes, spectral density function of them are presented. We assume that the process $\{X(t), t\in {\bf R^+}\}$ is also Markov in the wide sense and provide a discrete time scale invariant Markov (DT-SIM) process with the above scheme of sampling. We present an example of DT-SIM process, simple Brownian motion, by the above sampling scheme and verify our results. Finally we find the spectral density matrix of such DT-SIM process and show that its associated $T$-dimensional self-similar Markov process is fully specified by $\{R_{j}^H(1),R_{j}^H(0),j=0, 1,..., T-1\}$ where $R_j^H(\tau)$ is the covariance function of $j$th and $(j+\tau)$th observations of the process.Comment: 16 page

The Flow Field Upstream Of A Horizontal Axis Wind Turbine

A mathematical model is developed for a steady-state axi-symmetric upstream flow of a porous disc, in a uniform flow field . The special case of the upstream flow of a windmill, with and without a nacelle, is treated. First, the windmill is considered as a uniform distribution of sources and then as a linear distribution of sources. Solutions for the blade disc o f the wind field upstream are obtained in the form of stream1 ines and velocity vector components. Sample flow patterns upstream o f the blade disc o f the UMass 25 kW wind turbine are presented for several power levels. Documented computer programs applicable to any wind turbine are appended

The Effects of Obesity on Outcomes in Trauma Injury: Overview of the Current Literature

Obesity has reached epidemic proportions and is now considered a chronic disease by the National Institute of Health (NIH) in the West. Its impact on trauma outcomes is of particular interest with several studies presenting conflicting information. The present overview suggests a strong association between obesity and injury severity, hospital length of stay (LOS), intensive care unit (ICU) admission, pattern of injury, rate of complications and mortality. The nature of the observations may relate to an underlying physiological state of the obese patient and its associated comorbidities with a constant heightened inflammatory state aggravated by the second hit on an injury

Structuring communities for sharing human digital memories in a social P2P network

A community is sub-network inside P2P networks that partition the network into groups of similar peers to improve performance by reducing network traffic and high search query success rate. Large communities are common in online social networks than traditional file-sharing P2P networks because many people capture huge amounts of data through their lives. This increases the number of hosts bearing similar data in the network and hence increases the size of communities. This article presents a Memory Thread-based Communities for our Entity-based social P2P network that partition the network into groups of peers sharing data belonging to an entity–person, place, object or interest, having its own digital memory or be a part another memory. These connected peers having further similarities by organizing the network using linear orderings. A Memory-Thread is the collection of digital memories having a common reference key and organized according to some form of correlation. The simulation results show an increase in network performance for the proposed scheme along with a decrease in network overhead and higher query success rate compared to other similar schemes. The network maintains its performance even while the network traffic and size increase

Association of food allergies, cow�s milk allergy, and asthma with pediatric inflammatory bowel disease

There are controversies on the association of childhood allergic diseases with inflammatory bowel diseases (IBD). The aim of this study was to examine the association between food allergy, cow�s milk allergy (CMA), and asthma with pediatric IBD in Iranian population. This case-control study was conducted on 200 individuals less than 18-year-old (100 with IBD and 100 as control group). Medical records, clinical presentation, and laboratory and para-clinical findings related to food allergy, CMA, and asthma were reviewed for all participants in both groups and were recorded. Among 100 children with IBD, 40 had Crohn's disease, and 60 had ulcerative colitis. The frequency of food allergy, cow's milk allergy, and asthma in children with IBD was significantly higher than the control group (P<0.001). Asthma in children with Crohn's disease was significantly more prevalent than children with ulcerative colitis (P=0.008). Food allergy (OR: 22.1, 95 CI: 5.1-95.05, P<0.001), CMA (OR: 15, 95 CI: 3-67, P<0.001), and asthma (OR: 10, 95 CI: 3-37.05, P<0.001) were significantly associated with increased risk of IBD in children. Food allergy, CMA in infancy and asthma are more prevalent in children with different subtypes of IBD. The diagnosis of these risk factors is associated with increased risk of Crohn's disease and ulcerative colitis. © 2018 Tehran University of Medical Sciences. All rights reserved

Association of food allergies, cow�s milk allergy, and asthma with pediatric inflammatory bowel disease

There are controversies on the association of childhood allergic diseases with inflammatory bowel diseases (IBD). The aim of this study was to examine the association between food allergy, cow�s milk allergy (CMA), and asthma with pediatric IBD in Iranian population. This case-control study was conducted on 200 individuals less than 18-year-old (100 with IBD and 100 as control group). Medical records, clinical presentation, and laboratory and para-clinical findings related to food allergy, CMA, and asthma were reviewed for all participants in both groups and were recorded. Among 100 children with IBD, 40 had Crohn's disease, and 60 had ulcerative colitis. The frequency of food allergy, cow's milk allergy, and asthma in children with IBD was significantly higher than the control group (P<0.001). Asthma in children with Crohn's disease was significantly more prevalent than children with ulcerative colitis (P=0.008). Food allergy (OR: 22.1, 95 CI: 5.1-95.05, P<0.001), CMA (OR: 15, 95 CI: 3-67, P<0.001), and asthma (OR: 10, 95 CI: 3-37.05, P<0.001) were significantly associated with increased risk of IBD in children. Food allergy, CMA in infancy and asthma are more prevalent in children with different subtypes of IBD. The diagnosis of these risk factors is associated with increased risk of Crohn's disease and ulcerative colitis. © 2018 Tehran University of Medical Sciences. All rights reserved

The Effects of Obesity on Outcomes in Trauma Injury: Overview of the Current Literature

Obesity has reached epidemic proportions and is now considered a chronic disease by the National Institute of Health (NIH) in the West. Its impact on trauma outcomes is of particular interest with several studies presenting conflicting information. The present overview suggests a strong association between obesity and injury severity, hospital length of stay (LOS), intensive care unit (ICU) admission, pattern of injury, rate of complications and mortality. The nature of the observations may relate to an underlying physiological state of the obese patient and its associated comorbidities with a constant heightened inflammatory state aggravated by the second hit on an injury