Observers for invariant systems on Lie groups with biased input measurements and homogeneous outputs

This paper provides a new observer design methodology for invariant systems whose state evolves on a Lie group with outputs in a collection of related homogeneous spaces and where the measurement of system input is corrupted by an unknown constant bias. The key contribution of the paper is to study the combined state and input bias estimation problem in the general setting of Lie groups, a question for which only case studies of specific Lie groups are currently available. We show that any candidate observer (with the same state space dimension as the observed system) results in non-autonomous error dynamics, except in the trivial case where the Lie-group is Abelian. This precludes the application of the standard non-linear observer design methodologies available in the literature and leads us to propose a new design methodology based on employing invariant cost functions and general gain mappings. We provide a rigorous and general stability analysis for the case where the underlying Lie group allows a faithful matrix representation. We demonstrate our theory in the example of rigid body pose estimation and show that the proposed approach unifies two competing pose observers published in prior literature.Comment: 11 page

Linguistic Capital in Iran: Using Official Language or Mother Tongue

AbstractLinguistic capital has been the subject of interest and study to many linguists and sociolinguists in the past decade, a central point in this relation can be found in Bourdieu's (1992) claim that language is not simply an object of study; and that it is an instrument of action and power and also has the power to produce existence. This capitalism can be considered as a threatening factor for the national unity in bi or multilingual countries. Iran as a multilingual country is not an exception to this threat; however, few studies have addressed the issue in the society. In response to this shortcoming, the present study investigated linguistic capital in different situations to see how power is distributed among the languages of the country. Accordingly, Persian as the official language of the country and Turkish, Kurdish and Luri, major indigenous languages of the country, were brought under investigation. In so doing, a researcher-made questionnaire was administrated to 220 subjects who were all bilingual male and female within the age range of 18 to 80 having fourteen different professions. The results of the paired sample t-test analysis indicate meaningful difference in participants’ choice of mother tongue and Persian as the official language in non-official conditions which stands for the power of the latter. Moreover, the regression analysis demonstrated that age, gender, job, degree of education, field of study, and residency were significant for the prediction of the dependent variables. Yet, gender predicted the best. Therefore, EFL teachers should be aware of the power of each language the learners speak and distinguish the difference between the knowledge they possess and the language they use to express

Size/Layout Optimization of Truss Structures Using Vibrating Particles System Meta-heuristic Algorithm and its Improved Version

Vibrating Particles System (VPS) optimization is a newly made meta-heuristic algorithm to optimize problems by inspiration of the free vibration of viscous-damped systems with single degree of freedom. The agents are modeled as particles which systematically proceed toward their equilibrium conditions that are reached by the existing population and historically best position. To enhance the performance of the VPS algorithm, Enhanced Vibrating Particles System (EVPS) applies a new process for updating agent’s positions. This paper tries to improve the EVPS algorithm with the aim of reduction in the regulatory parameters’ effect on the algorithm's performance by reducing the regulatory parameters. To evaluate the performance of the proposed method, it is applied to four optimization problems of truss structures including mixed of discrete and continuous design search spaces with displacement, stress and buckling constraints. As a result, the proposed algorithm is a suitable method and more research can be done on it

Quasiperiodic criticality and spin-triplet superconductivity in superconductor-antiferromagnet moire patterns

Quasiperiodicity has long been known to be a potential platform to explore exotic phenomena, realizing an intricate middle point between ordered solids and disordered matter. In particular, quasiperiodic structures are promising playgrounds to engineer critical wavefunctions, a powerful starting point to engineer exotic correlated states. Here we show that systems hosting a quasiperiodic modulation of antiferromagnetism and spin-singlet superconductivity, as realized by atomic chains in twisted van der Waals materials, host a localization-delocalization transition as a function of the coupling strength. Associated with this transition, we demonstrate the emergence of a robust quasiperiodic critical point for arbitrary incommensurate potentials, that appears for generic relative weights of the spin-singlet superconductivity and antiferromagnetism. We show that the inclusion of residual electronic interactions leads to an emergent spin-triplet superconducting state, that gets dramatically enhanced at the vicinity of the quasiperiodic critical point. Our results put forward quasiperiodicity as a powerful knob to engineer robust superconducting states, providing an alternative pathway towards artificially designed unconventional superconductors.Comment: 11 pages, 5 figure

Complications leading to hospitalization due to consumption of anti-TB drugs in patients with tuberculosis in Gorgan, Iran (2007-12)

Background and Objective: Anti tuberculosis drugs therapy is the most effective method for controling the tuberculosis (TB). Early detection and appropriate treatment can prevent the TB-drug resistance. This study was carried out to determine the complications leading to hospitalization due to consumption of anti-TB drugs in patients with tuberculosis. Methods: In this descriptive-analytic study, 1550 records of patients with TB in urban and rural health centers of Gorgan, north of Iran were assessed during 2007-12. Checklist consists of demographic and clinical data for each patient was recorded in a questionare. Results: 44 cases experienced the complications of anti-TB drugs. 27 (61.4%) of cases with complications were women. 77.3% and 22.7% of patients affected with pulmonary and extra pulmonary tuberculosis,respectively. 38.6% of patients were diabetic. The hepatic complication was seen in 37 cases (84.1%). Skin and other complications were seen in 5 and 2 cases, respectively. There was not any relationship between drug complications and other disases. Conclusion: Hepatic damage is the most common complication leading to hospitalization in tuberculosis patients using anti-TB drugs. Keywords: Tuberculosis, Anti-TB drug, Live