Identification of cardiac signals in ambulatory ECG data

The Electrocardiogram (ECG) is the primary tool for monitoring heart function. ECG signals contain vital information about the heart which informs diagnosis and treatment of cardiac conditions. The diagnosis of many cardiac arrhythmias require long term and continuous ECG data, often while the participant engages in activity. Wearable ambulatory ECG (AECG) systems, such as the common Holter system, allow heart monitoring for hours or days. The technological trajectory of AECG systems aims towards continuous monitoring during a wide range of activities with data processed locally in real time and transmitted to a monitoring centre for further analysis. Furthermore, hierarchical decision systems will allow wearable systems to produce alerts or even interventions. These functions could be integrated into smartphones.A fundamental limitation of this technology is the ability to identify heart signal characteristics in ECG signals contaminated with high amplitude and non-stationary noise. Noise processing become more severe as activity levels increase, and this is also when many heart problems are present.This thesis focuses on the identification of heart signals in AECG data recorded during participant activity. In particular, it explored ECG filters to identify major heart conditions in noisy AECG data. Gold standard methods use Extended Kalman filters with extrapolation based on sum of Gaussian models. New methods are developed using linear Kalman filtering and extrapolation based on a sum of Principal Component basis signals. Unlike the gold standard methods, extrapolation is heartcycle by heartcycle. Several variants are explored where basic signals span one or two heartcycles, and applied to single or multi-channel ECG data.The proposed methods are extensively tested against standard databases or normal and abnormal ECG data and the performance is compared to gold standard methods. Two performance metrics are used: improvement in signal to noise ratio and the observability of clinically important features in the heart signal. In all tests the proposed method performs better, and often significantly better, than the gold standard methods. It is demonstrated that abnormal ECG signals can be identified in noisy AECG data

Public housing self-selection through user satisfaction in the City of Qom, Iran

This research is focusing on the concept of self-selection, a decision-making process grounded in self-concept, which currently receives less attention in housing provision in Iran. This is an effort to explore new suggestions for improving the level of user satisfaction for future living environments that are designed based on current architectural ideas. Achievement of self-selection is indicated by satisfaction in decision-making process. Therefore, the aim of this research is to enhance general housing satisfaction in Qom, Iran by improving the level of residential satisfaction of public housings through the decision making process for future designs. The objectives of this research are to investigate the attributes of the residential environment, related to user self-selection of public housings in Qom, and to measure the residential satisfaction level of public housings through various aspects of self-selection. Sequential mixed methods were employed based on post-occupancy evaluation questionnaire, which clarify the level of user satisfaction. The survey questionnaire was administered to a sample (N=109) of Iranian residents who live in the public housing of Mehr Projects in the Pardisan area of Qom. The collected data were processed with IBM SPSS, ANOVA, and Smart-PLS for frequency, t-tests and model testing. The results indicate that the mean score for user residential satisfaction, self-selection and overall quality of future design are above neutral. The findings suggest that the respondents were satisfied with their current experience of living in the apartments. The quality of current state of the building has improved, and the quality of future design needs less improvement. The results can be useful in assisting architects to predict residential satisfaction and subsequently consider the desired level of self-selection in their design process. In conclusion, the significant determinants of user satisfaction by different attributes of self-selection have been highlighted, and the findings show the central position of self-selection in architectural design

Double - stage H-Darrieus wind turbine - rotor aerodynamics

H-Darrieus wind turbines, due to their simple design and relatively low manufacturing costs have recently received much attention particularly for standalone applications. However start-up issues associated with their operation restricted their operation in areas of low average wind speed and encourages engineers to develop novel design. Several design proposed in this way but in most cases design came up with complex sensing mechanisms and mechanical actuators or high cost manufacturing parts. A recent rotor design called double Darrieus rotor proposed as a German patent case bridged these complexities appropriately. The aim of present study is to investigate this innovative design from aerodynamic point of view by means of validated CFD techniques. A flow-driven simulation setup based on 6DOF calculations employed in order to study rotor operation from stand still until peak performance obtained. Results from these precise modeling reveal the superiority of the proposed double-stage design in compare with the original H-Darrieus rotors in terms of start-up behavior and optimum performance

Modal behaviour of vertical axis wind turbine comprising prestressed rotor blades: a finite element analysis

Pre-stressing is a concept used in many engineering structures. In this study prestressing in the form of axial compression stress is proposed in the blade structure of H-Darrieus wind turbine. The study draws a structural comparison between reference and prestressed configurations of turbine rotor with respect to their dynamic vibrational response. Rotordynamics calculations provided by ANSYS Mechanical is used to investigate the effects of turbine rotation on the dynamic response of the system. Rotation speed ranging between 0 to 150 rad/s was examined to cover the whole operating range of commercial instances. The modal analysis ends up with first six mode shapes of both rotor configurations. As a result, the displacement of the proposed configurations reduced effectively. Apparent variations in Campbell diagrams of both cases indicate that prestressed configuration has its resonant frequencies far away from turbine operation speeds and thus remarkably higher safety factor against whirling and probable following failures

ULOGA INFORMACIJSKE TEHNOLOGIJE U KVALITETI FINANCIJSKOG IZVJEŠTAVANJA: PRIMJER IRANA

This paper investigates the role of information technology in financial reporting as well as the relationship between using information technology and its impact on the quality of financial reporting. To identify the impact of information technology on quality of financial reporting, a questionnaire was designed and developed. In order to test the hypotheses, T-Test, ANOVA and Duncan’s Test were employed. The results show that the information technology enhances the relevance and reduces the reliability of accounting information. It also increases comparability, albeit in a small amount, and diminishes the negative impact of dominant limitations on qualitative characteristics of accounting information.Ovaj rad istražuje ulogu informacijske tehnologije u financijskom izvještavanju, kao i vezu između korištenja informacijske tehnologije i njezinog utjecaja na kvalitetu financijskog izvještavanja. Kako bi se prepoznao utjecaj informacijske tehnologije na kvalitetu financijskog izvještavanja, izrađen je i razvijen upitnik. Kako bi se testirale hipoteze, korišteni su T-test, ANOVA i Duncanov test. Rezultati pokazuju kako informacijska tehnologija dovodi do većeg značaja ali i do smanjene pouzdanosti računovodstvenih podataka. Također dovodi do povećane usporedivosti, iako u smanjenom opsegu, te ima za posljedicu smanjeni negativni utjecaj dominantnih ograničenja kvalitativnih obilježja računovodstvenih podataka

Study on start-up characteristics of H-Darrieus vertical axis wind turbines comprising NACA 4-digit series blade airfoils

Installation of H-type vertical axis wind turbines is in many cases limited by the inherent start-up issues associated with this type of turbine. This could be crucial in environments with low wind speed. The aim of this study is to provide an appropriate CFD modeling setup for investigation of the start-up behavior associated with this class of turbines. For this purpose, a series of transient CFD simulations were carried out using ANSYS Fluent. In contrast with the conventional approach, whereby a constant angular velocity is specified for the rotor, in the present work, the turbine was left free to accelerate based on the torque experienced over time. Careful considerations were made regarding turbulence modeling and grid generation, which are key to ensuring accuracy in this investigation. The result of this simulation, in the form of an accelerating time series, demonstrates good agreement with the published experimental data, and the method yields a high level of accuracy, proving its usefulness for similar problems. In another attempt, the validated CFD setup was utilized to evaluate the effects of several geometric attributes of the turbine rotor on the starting characteristics. Symmetric and cambered airfoils of different thicknesses with a wide range of pitch angles were examined. The optimum start-up characteristics were observed with the use of a medium-thickness cambered airfoil, NACA2418, put to use with an outward pitch angle of 1.5°; this configuration decreased the start-up time while retaining the turbine's peak performance

Investigating the Efficacy of Sumac Topical Solution Against Permethrin-resistant Human Head Lice

Background: The present study aimed at determining the efficacy of applying Rhus coriaria (Sumac) solution for the treatment of Permethrin-resistant head louse in patients, who used permethrin for at least 2 consecutive periods, but have not been cured.Methods: This study is a before-after clinical trial performed on 100 patients with pediculosis aged between 2 and 50 years old and both sexes. All patients had used Permethrin at least twice consecutively (with at least 14 days interval) according to correct instructions (on the first and 7th day), but they have not been cured. Each patient received 60ml of Rhus coriaria solution for 3 consecutive days, and the treatment was repeated again for another 3 days; then, the patients were followed-up on the 4th, 10th, and14th days after the treatment.Results: The results showed a significant difference in the severity of head lice infection and itching before the treatment and 14 days after the treatment (P<0.001).Conclusion: Rhus coriaria solution was more effective in eliminating head-louse infestations on 4, 10, and 14 days after the treatment and itching disappeared in most of the patients, while negligible complications were observed

Considering user participation in light of level and stages of self-selection in architectural design process (ADP)

Presenting the new definition of self-selection in Architectural Design Process (ADP) needs to clarify the edges of this new concept versus the others, which exist in design area. Referring to conducting content analysis in previous published studies, the general meaning of self-selection is a situation in which user decide to do something for themselves rather than do something that has chosen for them. On the other hand, different users’ and designers’ vision of self-selection make a connection with End User’s Personalization (EUP) and User Centered Design (UCD). Both self-selection and user participation indicate the user decision-making power. Consequently, for earning a high level of user satisfaction, users should allow to contribute partially or totally, in certain decision-making processes, which have normally considered as the typical responsibility of architects. This paper by gathering a close group dissection and using brainstorming method, has attempted to argue the levels and stages of user participation in order to discover and establish the level and stages of self-selection in ADP

2-[(E)-(4-Methyl­phen­yl)imino­meth­yl]-6-(morpholin-4-ylmeth­yl)phenol

In the title compound, C19H22N2O2, the morpholine ring adopts an almost perfect normal chair conformation with puckering parameters Q T, θ and ϕ of 0.5642 (18) Å, 177.32 (17) and ϕ = 10 (4)°, respectively. The two benzene rings make a dihedral angle of 42.67 (8)° with each other. An intra­molecular O—H⋯N hydrogen bond helps to stabilize the mol­ecular conformation. Aromatic C—H⋯π inter­actions and π–π stacking inter­actions [centroid–centroid distance = 3.6155 (15) Å] between the benzene rings contribute to the stabilization of the crystal structure