On The Positive Definiteness of Polarity Coincidence Correlation Coefficient Matrix

Polarity coincidence correlator (PCC), when used to estimate the covariance matrix on an element-by-element basis, may not yield a positive semi-definite (PSD) estimate. Devlin et al. [1], claimed that element-wise PCC is not guaranteed to be PSD in dimensions p>3 for real signals. However, no justification or proof was available on this issue. In this letter, it is proved that for real signals with p<=3 and for complex signals with p<=2, a PSD estimate is guaranteed. Counterexamples are presented for higher dimensions which yield invalid covariance estimates.Comment: IEEE Signal Processing Letters, Volume 15, pp. 73-76, 200

Efficient Entanglement Measure for Graph States

In this paper, we study the multipartite entanglement properties of graph states up to seven qubits. Our analysis shows that the generalized concurrence measure is more efficient than geometric entanglement measure for measuring entanglement quantity in the multi-qubit graph states.Comment: 10 pages, 4 table

Walnut shell extract as sustainable, eco-friendly and cost-effective green corrosion inhibitor for fabrication of active protective nanocomposite coating based on mesoporous carbon hollow nanospheres

This paper presents anticorrosion performance of epoxy resin containing walnut extract as green inhibitor doped in mesoporous carbon hollow nanospheres (MCHNSs). In the first step, mesoporous silica hard templating method was used to fabricate carbon hollow nanospheres. In the second step, the extracted green inhibitor was loaded into the nanospheres (WE@MCHNSs) and on-demand active coating was fabricated by uniformly dispersing doped carbon nanospheres in epoxy matrix. The corrosion protection properties of the coatings were studied by electrochemical impedance spectroscopy (EIS), electrochemical noise measurement (ENM) and salt spray analysis. Corrosion resistance of the mild steel samples in the 3.5 wt. % NaCl solution in the presence and absence of walnut extract was compared. Salt spray and electrochemical impedance spectroscopy (EIS) results proved active protective behavior of the epoxy coating containing the doped MCNSs. It was shown that charge transfer resistance of the bare steel sample enhanced from ~ 610 Ω cm2 to ~ 4060 Ω cm2 in the presence of WE after 24 h immersion time. Also, the active corrosion protective performance of the scribed coatings was improved ~ 1450 % in the presence of WE@MCHNSs. The obtained results revealed that on-demand release of walnut green inhibitors from carbon nanospheres enhance protection performance of epoxy coatings. Furthermore, the fabricated epoxy coating demonstrated active protection behavior due to release of inhibitor caused by mechanical damage of carbon nanospheres shells (Figure 1). Please click Additional Files below to see the full abstract

Resilience, vulnerability and mental health

AbstractThis study investigated the association of resilience with indices of vulnerability including psychological distress, depression, and anxiety; and mental health in a sample of students. 214 (97 boys, 114 girls) were included in this study. All participants completed Connor-Davidson Resilience Scale (CD-RISC), Mental Health Inventory (MHI), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), and General Health Questionnaire (GHQ). resilience was positively associated with psychological well-being and negatively associated with psychological distress, depression and anxiety. Psychological health and vulnerability indices are influenced by different levels of resilience through self-esteem, personal competence and tenacity, tolerance of negative affect, control, and spirituality

Gradual transformation of public interest theory and its status in Iranian constitution law

Public interest theory in governance and its reflection in Constitution Law are recently emerging in public law literature. Its concept and function differs country-by-country based on governing ideology of the society. Liberal states usually construe this theory by considering individual orientation and social states by society priority. The concept of public interest and the mechanism to achieve it in law and ethics philosophy in general and in Iranian Constitution in particular is a disputing discussion. We assume that any school construes public interest by its selected ideology in law philosophy and political theory. Likewise, by Iranian Constitution Law, it is perceived that respecting expediency especially "system expediency" has broad usage in governance especially upon revolution. Although respecting customary expediency does not seem so surprising

Direction-of-Arrival Estimation for Temporally Correlated Narrowband Signals

signal direction-of-arrival estimation using an array of sensors has been the subject of intensive research and development during the last two decades. Efforts have been directed to both, better solutions for the general data model and to develop more realistic models. So far, many authors have assumed the data to be iid samples of a multivariate statistical model. Although this assumption reduces the complexity of the model, it may not be true in certain situations where signals show temporal correlation. Some results are available on the temporally correlated signal model in the literature. The temporally correlated stochastic Cramer-Rao bound (CRB) has been calculated and an instrumental variable-based method called IV-SSF is introduced. Also, it has been shown that temporally correlated CRB is lower bounded by the deterministic CRB. In this paper, we show that temporally correlated CRB is also upper bounded by the stochastic iid CRB. We investigate the effect of temporal correlation of the signals on the best achievable performance. We also show that the IV-SSF method is not efficient and based on an analysis of the CRB, propose a variation in the method which boosts its performance. Simulation results show the improved performance of the proposed method in terms of lower bias and error variance.Comment: IEEE Transactions on Signal Processing, vol. 57, pp. 600-609, Feb. 200

Statistical Performance Analysis of MDL Source Enumeration in Array Processing

In this correspondence, we focus on the performance analysis of the widely-used minimum description length (MDL) source enumeration technique in array processing. Unfortunately, available theoretical analysis exhibit deviation from the simulation results. We present an accurate and insightful performance analysis for the probability of missed detection. We also show that the statistical performance of the MDL is approximately the same under both deterministic and stochastic signal models. Simulation results show the superiority of the proposed analysis over available results.Comment: Accepted for publication in IEEE Transactions on Signal Processing, April 200

Epidemiological Pattern of Injuries in Iran; a Nationwide Review of Seven Million Emergency Department Admissions

Introduction: Globally, it is estimated that around 5.8 million people die annually as result of injuries, which causes 10% of all deaths and 16% of disability adjusted life years lost worldwide. This study aimed to determine the epidemiology of injuries in emergency departments in Iran.Method: This cross sectional study was carried out using national injury surveillance data registry from 21 March 2009 to 20 March 2014.Results: 7,176,344 patients with the mean age of 27.5 ± 17.8 years were registered to 657 EDs (70.6% male). Road Traffic Crash (RTC) was the most common cause of injury (31.0%) followed by hit (28.2%) and fall (10.1%). While roads were the commonest place of injuries, 34.0% of patients have been injured at home. More than 90% of injuries were unintentional. Assault and suicide attempt were causes of injury in 5.6% and 3.9% of patients, respectively.Conclusion:This paper addresses where prevention measures are most urgently needed and offers insights which could be useful for injury prevention programs in Iran and other developing countries