Search results for: regional flood frequency
4822 Induction Motor Eccentricity Fault Recognition Using Rotor Slot Harmonic with Stator Current Technique
Authors: Nouredine Benouzza, Ahmed Hamida Boudinar, Azeddine Bendiabdellah
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An algorithm for Eccentricity Fault Detection (EFD) applied to a squirrel cage induction machine is proposed in this paper. This algorithm employs the behavior of the stator current spectral analysis and the localization of the Rotor Slot Harmonic (RSH) frequency to detect eccentricity faults in three phase induction machine. The RHS frequency once obtained is used as a key parameter into a simple developed expression to directly compute the eccentricity fault frequencies in the induction machine. Experimental tests performed for both a healthy motor and a faulty motor with different eccentricity fault severities illustrate the effectiveness and merits of the proposed EFD algorithm.Keywords: squirrel cage motor, diagnosis, eccentricity faults, current spectral analysis, rotor slot harmonic
Procedia PDF Downloads 4874821 Depiction of a Circulated Double Psi-Shaped Microstrip Antenna for Ku-Band Satellite Applications
Authors: M. Naimur Rahman, Mohammad Tariqul Islam, Mandeep Singh Jit Singh, Norbahiah Misran
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This paper presents the architecture and exploration of a compact, circulated double Psi-shaped microstrip patch antenna for Ku-band satellite applications. The antenna is composed of the double Psi-shaped patch in opposite focus which is circulated with a ring. The antenna size is 24 mm × 18 mm and the prototype is imprinted on Rogers RT/duroid 5880 materials with the depth of 1.57 mm. The substrate has a relative permittivity of 2.2 and the dielectric constant of 0.0009. The excitation is supplied through a 50Ω microstrip line. The performance of the presented antenna has been simulated and verified with the High-Frequency Structural Simulator (HFSS). The results depict that the antenna covers the frequency spectrum 14.6 - 17.4 GHz (Ku-band) with 10 dB return loss. The antenna has a 4.40 dBi maximum gain with stable radiation patterns throughout the operating band which makes the proposed antenna compatible for the satellite application in Ku-band.Keywords: Ku-band antenna, microstrip antenna, psi-shaped antenna, satellite applications
Procedia PDF Downloads 3094820 Frequency Decomposition Approach for Sub-Band Common Spatial Pattern Methods for Motor Imagery Based Brain-Computer Interface
Authors: Vitor M. Vilas Boas, Cleison D. Silva, Gustavo S. Mafra, Alexandre Trofino Neto
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Motor imagery (MI) based brain-computer interfaces (BCI) uses event-related (de)synchronization (ERS/ ERD), typically recorded using electroencephalography (EEG), to translate brain electrical activity into control commands. To mitigate undesirable artifacts and noise measurements on EEG signals, methods based on band-pass filters defined by a specific frequency band (i.e., 8 – 30Hz), such as the Infinity Impulse Response (IIR) filters, are typically used. Spatial techniques, such as Common Spatial Patterns (CSP), are also used to estimate the variations of the filtered signal and extract features that define the imagined motion. The CSP effectiveness depends on the subject's discriminative frequency, and approaches based on the decomposition of the band of interest into sub-bands with smaller frequency ranges (SBCSP) have been suggested to EEG signals classification. However, despite providing good results, the SBCSP approach generally increases the computational cost of the filtering step in IM-based BCI systems. This paper proposes the use of the Fast Fourier Transform (FFT) algorithm in the IM-based BCI filtering stage that implements SBCSP. The goal is to apply the FFT algorithm to reduce the computational cost of the processing step of these systems and to make them more efficient without compromising classification accuracy. The proposal is based on the representation of EEG signals in a matrix of coefficients resulting from the frequency decomposition performed by the FFT, which is then submitted to the SBCSP process. The structure of the SBCSP contemplates dividing the band of interest, initially defined between 0 and 40Hz, into a set of 33 sub-bands spanning specific frequency bands which are processed in parallel each by a CSP filter and an LDA classifier. A Bayesian meta-classifier is then used to represent the LDA outputs of each sub-band as scores and organize them into a single vector, and then used as a training vector of an SVM global classifier. Initially, the public EEG data set IIa of the BCI Competition IV is used to validate the approach. The first contribution of the proposed method is that, in addition to being more compact, because it has a 68% smaller dimension than the original signal, the resulting FFT matrix maintains the signal information relevant to class discrimination. In addition, the results showed an average reduction of 31.6% in the computational cost in relation to the application of filtering methods based on IIR filters, suggesting FFT efficiency when applied in the filtering step. Finally, the frequency decomposition approach improves the overall system classification rate significantly compared to the commonly used filtering, going from 73.7% using IIR to 84.2% using FFT. The accuracy improvement above 10% and the computational cost reduction denote the potential of FFT in EEG signal filtering applied to the context of IM-based BCI implementing SBCSP. Tests with other data sets are currently being performed to reinforce such conclusions.Keywords: brain-computer interfaces, fast Fourier transform algorithm, motor imagery, sub-band common spatial patterns
Procedia PDF Downloads 1284819 The Greek Version of the Southampton Nostalgia Scale: Psychometric Properties in Young Adults and Associations with Life Satisfaction, Positive and Negative Emotions, Time Perspective and Wellbeing
Authors: Eirini Petratou, Pezirkianidis Christos, Anastassios Stalikas
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Nostalgia is characterized as a mental state of human’s emotional longing for the past that activates both positive and negative emotions. The bittersweet emotions that are activated by nostalgia aid psychological functions to humans and are depended on the type of stimuli that evoke nostalgia but also on the nostalgia activation context. In general, despite that nostalgia can be activated and experienced by all people; however, it differs both in terms of nostalgia experience but also nostalgia frequency. As a matter of fact, nostalgia experience along with nostalgia frequency differs according to the level of the nostalgia proneness. People with high nostalgia proneness tend to experience nostalgia more intensely and frequently than people with low nostalgia proneness. Nostalgia proneness is considered as a basic individual difference that affects the experience of nostalgia, and it can be measured by the Southampton Nostalgia Scale (SNS); a psychometric instrument that measures human’s nostalgia proneness consisting of seven questions that assess a person’s attitude towards nostalgia, the degree of experience or tendency to nostalgic feelings and the nostalgia frequency. In the current study, we translated, validated and calibrated the SNS in Greek population (N = 267). For the calibration process, we used several scales relevant to positive dimensions, such as life satisfaction, positive and negative emotions, time perspective and wellbeing. A confirmatory factor analysis revealed the factors that provide a good Southampton Nostalgia Proneness model fit for young adult Greek population.Keywords: nostalgia proneness, nostalgia, psychometric instruments, psychometric properties
Procedia PDF Downloads 1514818 Numerical Investigation on Feasibility of Electromagnetic Wave as Water Hardness Detection in Water Cooling System Industrial
Authors: K. H. Teng, A. Shaw, M. Ateeq, A. Al-Shamma'a, S. Wylie, S. N. Kazi, B. T. Chew
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Numerical and experimental of using novel electromagnetic wave technique to detect water hardness concentration has been presented in this paper. Simulation is powerful and efficient engineering methods which allow for a quick and accurate prediction of various engineering problems. The RF module is used in this research to predict and design electromagnetic wave propagation and resonance effect of a guided wave to detect water hardness concentration in term of frequency domain, eigenfrequency, and mode analysis. A cylindrical cavity resonator is simulated and designed in the electric field of fundamental mode (TM010). With the finite volume method, the three-dimensional governing equations were discretized. Boundary conditions for the simulation were the cavity materials like aluminum, two ports which include transmitting and receiving port, and assumption of vacuum inside the cavity. The design model was success to simulate a fundamental mode and extract S21 transmission signal within 2.1 – 2.8 GHz regions. The signal spectrum under effect of port selection technique and dielectric properties of different water concentration were studied. It is observed that the linear increment of magnitude in frequency domain when concentration increase. The numerical results were validated closely by the experimentally available data. Hence, conclusion for the available COMSOL simulation package is capable of providing acceptable data for microwave research.Keywords: electromagnetic wave technique, frequency domain, signal spectrum, water hardness concentration
Procedia PDF Downloads 2724817 Dielectric and Impedance Spectroscopy of Samarium and Lanthanum Doped Barium Titanate at Room Temperature
Authors: Sukhleen Bindra Narang, Dalveer Kaur, Kunal Pubby
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Dielectric ceramic samples in the BaO-Re2O3-TiO2 ternary system were synthesized with structural formula Ba2-xRe4+2x/3Ti8O24 where Re= rare earth metal and Re= Sm and La where x varies from 0.0 to 0.6 with step size 0.1. Polycrystalline samples were prepared by the conventional solid state reaction technique. The dielectric, electrical and impedance analysis of all the samples in the frequency range 1KHz- 1MHz at room temperature (25°C) have been done to get the understanding of electrical conduction and dielectric relaxation and their correlation. Dielectric response of the samples at lower frequencies shows dielectric dispersion while at higher frequencies it shows dielectric relaxation. The ac conductivity is well fitted by the Jonscher law (σac = σdc+Aωn). The spectroscopic data in the impedance plane confirms the existence of grain contribution to the relaxation. All the properties are found out to be function of frequency as well as the amount of substitution.Keywords: dielectric ceramics, dielectric constant, loss tangent, AC conductivity, impedance spectroscopy
Procedia PDF Downloads 4554816 A Corpus-Based Analysis of Japanese Learners' English Modal Auxiliary Verb Usage in Writing
Authors: S. Nakayama
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For non-native English speakers, using English modal auxiliary verbs appropriately can be among the most challenging tasks. This research sought to identify differences in modal verb usage between Japanese non-native English speakers (JNNS) and native speakers (NS) from two different perspectives: frequency of use and distribution of verb phrase structures (VPS) where modal verbs occur. This study can contribute to the identification of JNNSs' interlanguage with regard to modal verbs; the main aim is to make a suggestion for the improvement of teaching materials as well as to help language teachers to be able to teach modal verbs in a way that is helpful for learners. To address the primary question in this study, usage of nine central modals (‘can’, ‘could’, ‘may’, ‘might’, ‘shall’, ‘should’, ‘will’, ‘would’, and ‘must’) by JNNS was compared with that by NSs in the International Corpus Network of Asian Learners of English (ICNALE). This corpus is one of the largest freely-available corpora focusing on Asian English learners’ language use. The ICNALE corpus consists of four modules: ‘Spoken Monologue’, ‘Spoken Dialogue’, ‘Written Essays’, and ‘Edited Essays’. Among these, this research adopted the ‘Written Essays’ module only, which is the set of 200-300 word essays and contains approximately 1.3 million words in total. Frequency analysis revealed gaps as well as similarities in frequency order. Specifically, both JNNSs and NSs used ‘can’ with the most frequency, followed by ‘should’ and ‘will’; however, usage of all the other modals except for ‘shall’ was not identical to each other. A log-likelihood test uncovered JNNSs’ overuse of ‘can’ and ‘must’ as well as their underuse of ‘will’ and ‘would’. VPS analysis revealed that JNNSs used modal verbs in a relatively narrow range of VPSs as compared to NSs. Results showed that JNNSs used most of the modals with bare infinitives or the passive voice only whereas NSs used the modals in a wide range of VPSs including the progressive construction and the perfect aspect, both of which were the structures where JNNSs rarely used the modals. Results of frequency analysis suggest that language teachers or teaching materials should explain other modality items so that learners can avoid relying heavily on certain modals and have a wide range of lexical items to reflect their feelings more accurately. Besides, the underused modals should be more stressed in the classroom because they are members of epistemic modals, which allow us to not only interject our views into propositions but also build a relationship with readers. As for VPSs, teaching materials should present more examples of the modals occurring in a wide range of VPSs to help learners to be able to express their opinions from a variety of viewpoints.Keywords: corpus linguistics, Japanese learners of English, modal auxiliary verbs, International Corpus Network of Asian Learners of English
Procedia PDF Downloads 1274815 Perception of Authorities in Social Support by Students under the Conditions of Inclusive Education
Authors: Jarmila Zolnova, Lucia Hrebenarova, Veronika Palkova
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The interconnections between supportive sources of authorities at school and students have been proved. Lacking research in this field in Slovakia translates into absenting perception of social support by students with special educational needs. The aim of this paper (presented by the poster) is to reveal and interpret the perception of frequency and importance of authorities at school from students' perspective. The sample included 718 students aged 10 years and 1 month on average. Eighty nine students of this count were students with special educational needs. Data were obtained from the Child and Adolescent Social Support Scale (CASSS) for students. Mutual relations between teachers acting as the source of support and students were not significant. Neither was significant the support of other school employees. Both groups of students assessed the frequency and importance of social support from teachers more positively than the support from other school employees.Keywords: intact student, pedagogue, pupil with special education needs, school employee, social support
Procedia PDF Downloads 3474814 A Study on the Etching Characteristics of High aspect ratio Oxide Etching Using C4F6 Plasma in Inductively Coupled Plasma with Low Frequency Bias
Authors: ByungJun Woo
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In this study, high-aspect-ratio (HAR) oxide etching characteristics in inductively coupled plasma were investigated using low frequency (2 MHz) bias power with C4F6 gas. An experiment was conducted using CF4/C4F6/He as the mixed gas. A 100 nm (etch area)/500 nm (mask area) line patterns were used, and the etch cross-section and etch selectivity of the amorphous carbon layer thin film were derived using a scanning electron microscope. Ion density was extracted using a double Langmuir probe, and CFx and F neutral species were observed via optical emission spectroscopy. Based on these results, the possibility for HAR oxide etching using C4F6 gas chemistry was suggested in this work. These etching results also indicate that the use of C4F6 gas can significantly contribute to the development of next-generation HAR oxide etching.Keywords: plasma, etching, C4F6, high aspect ratio, inductively coupled plasma
Procedia PDF Downloads 734813 Apolipoprotein A1 -75 G to a Substitution and Its Relationship with Serum ApoA1 Levels among Indian Punjabi Population
Authors: Savjot Kaur, Mridula Mahajan, AJS Bhanwer, Santokh Singh, Kawaljit Matharoo
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Background: Disorders of lipid metabolism and genetic predisposition are CAD risk factors. ApoA1 is the apolipoprotein component of anti-atherogenic high density lipoprotein (HDL) particles. The protective action of HDL and ApoA1 is attributed to their central role in reverse cholesterol transport (RCT). Aim: This study was aimed at identifying sequence variations in ApoA1 (-75G>A) and its association with serum ApoA1 levels. Methods: A total of 300 CAD patients and 300 Normal individuals (controls) were analyzed. PCR-RFLP method was used to determine the DNA polymorphism in the ApoA1 gene, PCR products digested with restriction enzyme MspI, followed by Agarose Gel Electrophoresis. Serum apolipoprotein A1 concentration was estimated with immunoturbidimetric method. Results: Deviation from Hardy- Weinberg Equilibrium (HWE) was observed for this gene variant. The A- allele frequency was higher among Coronary Artery disease patients (53.8) compared to controls (45.5), p= 0.004, O.R= 1.38(1.11-1.75). Under recessive model analysis (AA vs. GG+GA) AA genotype of ApoA1 G>A substitution conferred ~1 fold increased risk towards CAD susceptibility (p= 0.002, OR= 1.72(1.2-2.43). With serum ApoA1 levels < 107 A allele frequency was higher among CAD cases (50) as compared to controls (43.4) [p=0.23, OR= 1.2(0.84-2)] and there was zero % occurrence of A allele frequency in individuals with ApoA1 levels > 177. Conclusion: Serum ApoA1 levels were associated with ApoA1 promoter region variation and influence CAD risk. The individuals with the APOA1 -75 A allele confer excess hazard of developing CAD as a result of its effect on low serum concentrations of ApoA1.Keywords: apolipoprotein A1 (G>A) gene polymorphism, coronary artery disease (CAD), reverse cholesterol transport (RCT)
Procedia PDF Downloads 3154812 Rain Gauges Network Optimization in Southern Peninsular Malaysia
Authors: Mohd Khairul Bazli Mohd Aziz, Fadhilah Yusof, Zulkifli Yusop, Zalina Mohd Daud, Mohammad Afif Kasno
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Recent developed rainfall network design techniques have been discussed and compared by many researchers worldwide due to the demand of acquiring higher levels of accuracy from collected data. In many studies, rain-gauge networks are designed to provide good estimation for areal rainfall and for flood modelling and prediction. In a certain study, even using lumped models for flood forecasting, a proper gauge network can significantly improve the results. Therefore existing rainfall network in Johor must be optimized and redesigned in order to meet the required level of accuracy preset by rainfall data users. The well-known geostatistics method (variance-reduction method) that is combined with simulated annealing was used as an algorithm of optimization in this study to obtain the optimal number and locations of the rain gauges. Rain gauge network structure is not only dependent on the station density; station location also plays an important role in determining whether information is acquired accurately. The existing network of 84 rain gauges in Johor is optimized and redesigned by using rainfall, humidity, solar radiation, temperature and wind speed data during monsoon season (November – February) for the period of 1975 – 2008. Three different semivariogram models which are Spherical, Gaussian and Exponential were used and their performances were also compared in this study. Cross validation technique was applied to compute the errors and the result showed that exponential model is the best semivariogram. It was found that the proposed method was satisfied by a network of 64 rain gauges with the minimum estimated variance and 20 of the existing ones were removed and relocated. An existing network may consist of redundant stations that may make little or no contribution to the network performance for providing quality data. Therefore, two different cases were considered in this study. The first case considered the removed stations that were optimally relocated into new locations to investigate their influence in the calculated estimated variance and the second case explored the possibility to relocate all 84 existing stations into new locations to determine the optimal position. The relocations of the stations in both cases have shown that the new optimal locations have managed to reduce the estimated variance and it has proven that locations played an important role in determining the optimal network.Keywords: geostatistics, simulated annealing, semivariogram, optimization
Procedia PDF Downloads 3024811 Thermally Stable Nanocrystalline Aluminum Alloys Processed by Mechanical Alloying and High Frequency Induction Heat Sintering
Authors: Hany R. Ammar, Khalil A. Khalil, El-Sayed M. Sherif
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The as-received metal powders were used to synthesis bulk nanocrystalline Al; Al-10%Cu; and Al-10%Cu-5%Ti alloys using mechanical alloying and high frequency induction heat sintering (HFIHS). The current study investigated the influence of milling time and ball-to-powder (BPR) weight ratio on the microstructural constituents and mechanical properties of the processed materials. Powder consolidation was carried out using a high frequency induction heat sintering where the processed metal powders were sintered into a dense and strong bulk material. The sintering conditions applied in this process were as follow: heating rate of 350°C/min; sintering time of 4 minutes; sintering temperature of 400°C; applied pressure of 750 Kgf/cm2 (100 MPa); cooling rate of 400°C/min and the process was carried out under vacuum of 10-3 Torr. The powders and the bulk samples were characterized using XRD and FEGSEM techniques. The mechanical properties were evaluated at various temperatures of 25°C, 100°C, 200°C, 300°C and 400°C to study the thermal stability of the processed alloys. The bulk nanocrystalline Al; Al-10%Cu; and Al-10%Cu-5%Ti alloys displayed extremely high hardness values even at elevated temperatures. The Al-10%Cu-5%Ti alloy displayed the highest hardness values at room and elevated temperatures which are related to the presence of Ti-containing phases such as Al3Ti and AlCu2Ti, these phases are thermally stable and retain the high hardness values at elevated temperatures up to 400ºC.Keywords: nanocrystalline aluminum alloys, mechanical alloying, hardness, elevated temperatures
Procedia PDF Downloads 4544810 Ranking of Provinces in Iran for Capital Formation in Spatial Planning with Numerical Taxonomy Technique (An Improvement) Case Study: Agriculture Sector
Authors: Farhad Nouparast
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For more production we need more capital formation. Capital formation in each country should be based on comparative advantages in different economic sectors due to the different production possibility curves. In regional planning, recognizing the relative advantages and consequently investing in more production requires identifying areas with the necessary capabilities and location of each region compared to other regions. In this article, ranking of Iran's provinces is done according to the specific and given variables as the best investment position in agricultural activity. So we can provide the necessary background for investment analysis in different regions of the country to formulate national and regional planning and execute investment projects. It is used factor analysis technique and numerical taxonomy analysis to do this in thisarticle. At first, the provinces are homogenized and graded according to the variables using cross-sectional data obtained from the agricultural census and population and housing census of Iran as data matrix. The results show that which provinces have the most potential for capital formation in agronomy sub-sector. Taxonomy classifies organisms based on similar genetic traits in biology and botany. Numerical taxonomy using quantitative methods controls large amounts of information and get the number of samples and categories and take them based on inherent characteristics and differences indirectly accommodates. Numerical taxonomy is related to multivariate statistics.Keywords: Capital Formation, Factor Analysis, Multivariate statistics, Numerical Taxonomy Analysis, Production, Ranking, Spatial Planning
Procedia PDF Downloads 1404809 Impact of Paint Occupational Exposure on Reproductive Markers: A Case Study in North East Algeria
Authors: Amina Merghad, Cherif Abdennour
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Solvents are widely used in paint industry, where humans are highly exposed, especially from inhalation. A case report describes how paint affects reproductive markers and the health of workers. Sixty four subjects were chosen and divided into two groups; a control and an exposed group. A questionnaire was given to male workers from similar socio-economic status in order to know their ages, working conditions, clinical symptoms, working period, smoking history, shift, medical history and nutrition. Blood was withdrawn in the morning from volunteers. The measurement of blood testosterone and prolactin concentrations was then carried out. Results showed that the ages of the two groups were almost similar and were up to 47 and 43 years. The period of employment was 17 years and 14 years for the control and the exposed workers, respectively. Concerning clinical symptoms, the frequency of neuropsychological symptoms of the two groups are presented. It is clear that the symptom of memory loss, headaches are the highest among exposed workers followed by poor coordination, poor concentration and insomnia. On the other hand, the symptoms’ frequency in the control was less than that of the exposed group. Testosterone concentration has significantly decreased in group 2 (4.61±2,005 ng/ml) and group 3 (4.25±1.67 ng/ml) of exposed workers. On the other hand, prolactin concentration was higher in group 3 compared to other groups. To conclude, paint industry has disturbed reproductive markers and created high frequency of neuropsychological symptoms.Keywords: blood, paint, prolactin, occupational exposure, organic solvent, reproductive toxicity, testosterone
Procedia PDF Downloads 3664808 A New Resonance Solution to Suppress the Voltage Stresses in the Forward Topology Used in a Switch Mode Power Supply
Authors: Maamar Latroch, Mohamed Bourahla
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Forward topology used in switch mode power supply (SMPS) is one of the most famous configuration feeding DC systems such as telecommunication systems and other specific applications where the galvanic isolation is required. This configuration benefits of the high frequency feature of the transformer to provide a small size and light weight of the over all system. However, the stresses existing on the power switch during an ON/OFF commutation limit the transmitted power to the DC load. This paper investigates the main causes of the stresses in voltage existing during a commutation cycle and suggest a low cost solution that eliminates the overvoltage. As a result, this configuration will yield the possibility of the use of this configuration in higher power applications. Simulation results will show the efficiency of the presented method.Keywords: switch mode power supply, forward topology, resonance topology, high frequency commutation
Procedia PDF Downloads 4374807 The Role of Identity Politics in the 2023 General Election in Nigeria: An Overview
Authors: Adekunle Saheed Ajisebiyawo
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This paper examines the influence of identity politics on the development of electoral democracy in Nigeria. The paper was anchored on a theory of African democracy adopted the qualitative methodology and deployed data from secondary sources to evaluate the 2023 presidential election, and found that ethnicity, religion, and regional sentiments played a major role in the election. The practical implications of this paper are that while Nigeria’s democracy is tending towards consolidation, if the unexpected does not happen, e.g., military takeover, religious and ethnic identities can mar the country’s development as competent candidates that have good policies will be voted out based on religious and ethnic sentiments. Thus, there is a need to de-emphasize religion and ethnicity in the Nigerian polity. Candidates and parties that campaign based on racial or religious narratives should be barred from contesting elective positions. The paper concluded that identity politics is inimical to Nigeria’s democratization process as well as efforts aimed at uniting and integrating the country; it, therefore, recommended that to establish a sound electoral democracy and a strong united country, the menace of ethnic, religious, and regional cleavages should be addressed. To achieve this, efforts should be intensified towards providing a set of principles for nation-building which should be included in the constitution. In addition, the paper urges the media to support the formation of an inclusive government, cutting across tribes and religions in the country to reduce the negative impact of ethnicity and religion in the country.Keywords: cleavages, democracy, ethnicity, election, identity politics, religion
Procedia PDF Downloads 604806 An Improved Adaptive Dot-Shape Beamforming Algorithm Research on Frequency Diverse Array
Authors: Yanping Liao, Zenan Wu, Ruigang Zhao
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Frequency diverse array (FDA) beamforming is a technology developed in recent years, and its antenna pattern has a unique angle-distance-dependent characteristic. However, the beam is always required to have strong concentration, high resolution and low sidelobe level to form the point-to-point interference in the concentrated set. In order to eliminate the angle-distance coupling of the traditional FDA and to make the beam energy more concentrated, this paper adopts a multi-carrier FDA structure based on proposed power exponential frequency offset to improve the array structure and frequency offset of the traditional FDA. The simulation results show that the beam pattern of the array can form a dot-shape beam with more concentrated energy, and its resolution and sidelobe level performance are improved. However, the covariance matrix of the signal in the traditional adaptive beamforming algorithm is estimated by the finite-time snapshot data. When the number of snapshots is limited, the algorithm has an underestimation problem, which leads to the estimation error of the covariance matrix to cause beam distortion, so that the output pattern cannot form a dot-shape beam. And it also has main lobe deviation and high sidelobe level problems in the case of limited snapshot. Aiming at these problems, an adaptive beamforming technique based on exponential correction for multi-carrier FDA is proposed to improve beamforming robustness. The steps are as follows: first, the beamforming of the multi-carrier FDA is formed under linear constrained minimum variance (LCMV) criteria. Then the eigenvalue decomposition of the covariance matrix is performed to obtain the diagonal matrix composed of the interference subspace, the noise subspace and the corresponding eigenvalues. Finally, the correction index is introduced to exponentially correct the small eigenvalues of the noise subspace, improve the divergence of small eigenvalues in the noise subspace, and improve the performance of beamforming. The theoretical analysis and simulation results show that the proposed algorithm can make the multi-carrier FDA form a dot-shape beam at limited snapshots, reduce the sidelobe level, improve the robustness of beamforming, and have better performance.Keywords: adaptive beamforming, correction index, limited snapshot, multi-carrier frequency diverse array, robust
Procedia PDF Downloads 1304805 Multi-Temporal Mapping of Built-up Areas Using Daytime and Nighttime Satellite Images Based on Google Earth Engine Platform
Authors: S. Hutasavi, D. Chen
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The built-up area is a significant proxy to measure regional economic growth and reflects the Gross Provincial Product (GPP). However, an up-to-date and reliable database of built-up areas is not always available, especially in developing countries. The cloud-based geospatial analysis platform such as Google Earth Engine (GEE) provides an opportunity with accessibility and computational power for those countries to generate the built-up data. Therefore, this study aims to extract the built-up areas in Eastern Economic Corridor (EEC), Thailand using day and nighttime satellite imagery based on GEE facilities. The normalized indices were generated from Landsat 8 surface reflectance dataset, including Normalized Difference Built-up Index (NDBI), Built-up Index (BUI), and Modified Built-up Index (MBUI). These indices were applied to identify built-up areas in EEC. The result shows that MBUI performs better than BUI and NDBI, with the highest accuracy of 0.85 and Kappa of 0.82. Moreover, the overall accuracy of classification was improved from 79% to 90%, and error of total built-up area was decreased from 29% to 0.7%, after night-time light data from the Visible and Infrared Imaging Suite (VIIRS) Day Night Band (DNB). The results suggest that MBUI with night-time light imagery is appropriate for built-up area extraction and be utilize for further study of socioeconomic impacts of regional development policy over the EEC region.Keywords: built-up area extraction, google earth engine, adaptive thresholding method, rapid mapping
Procedia PDF Downloads 1254804 Frequency of Surgical Complications in Diabetic Patients after Kidney Transplantation
Authors: Hakan Duger, Alparslan Ersoy, Canan Ersoy
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The improvement of surgical techniques in recent years has reduced the frequency of postoperative complications in kidney transplant recipients. Novel immunosuppressive agents have reduced rates of graft loss due to acute rejection to less than 1%. However, surgical complications may still lead graft loss and morbidity in recipients. Because of potent immunosuppression, impaired wound healing and complications are frequent after transplantation. We compared the frequency of post-operative surgical complications in diabetic and non-diabetic patients after kidney transplantation. Materials and Methods: This retrospective study conducted in consecutive patients (213 females, 285 males, median age 39 years) who underwent kidney transplant surgery at our center between December 2005 and October 2015. The patients were divided into two groups: diabetics (46 ± 10 year, 26 males, 16 females) and non-diabetics (39 ± 12 year, 259 males, 197 females). Characteristics of both groups were obtained from medical records. Results: We performed 225 living and 273 deceased donor transplantations. Renal replacement type was hemodialysis in 60.8%, peritoneal dialysis in 17.3% and preemptive in 12%. The mean body mass indexes of the recipients were 24 ± 4.6 kg/m², donor age was 48.6 ± 14.3 years, cold ischemic time was 11.3 ± 6.1 hours, surgery time was 4.9 ± 1.2 hours, and recovery time was 54±31 min. The mean hospitalization duration was 19.1 ± 13.5 days. The frequency of postoperative surgical complications was 43.8%. There was no significant difference between the ratios of post-operative surgical complications in non-diabetic (43.5%) and diabetic (47.4%) groups (p=0.648). Post-operative surgical complications were lymphocele (24.6% vs. 23.7%), delayed wound healing (13.2% vs. 7.6%), hematoma (7.8% vs.15.8 %), urinary leak (4.6% vs. 5.3%), hemorrhage (5.1% vs. 0%), hydronephrosis (2.2% vs. 0%), renal artery thrombosis (1.5% vs. 0%), renal vein thrombosis (1% vs. 2.6%), urinoma (0.7% vs. 0%), urinary obstruction (0.5% vs. 0%), ureteral stenosis (0.5% vs. 0%) and ureteral reflux (0.2% vs. 0%) in non-diabetic and diabetic groups, respectively (p > 0.05). Mean serum creatinine levels in non-diabetics and diabetics were 1.43 ± 0.81 and 1.61 ± 0.96 mg/dL at 1st month (p=0.198). At the 6th month, the mean graft and patient survival times in patients with post-operative surgical complications were significantly lower than in those who did not (162.9 ± 3.4 vs. 175.6 ± 1.5 days, p=0.008, and 171 ± 2.9 vs. 176.1 ± 1.6 days, p=0.047, respectively). However, patient survival durations of non-diabetic (173 ± 27) and diabetic (177 ± 13 day) groups were comparable (p=0.396). Conclusion: As a result, we concluded that surgical complications such as lymphocele and delayed wound healing were common and that frequency of these complications in diabetic recipients did not differ from non-diabetic one. All persons involved in the postoperative care of kidney transplant recipients be aware of the potential surgical complications for rapid diagnosis and treatment.Keywords: kidney transplantation, diabetes mellitus, surgery, complication
Procedia PDF Downloads 1784803 The Tourism in the Regional Development of South Caucasus
Authors: Giorgi Sulashvili, Vladimer Kekenadze, Olga Khutsishvili, Bela Khotenashvili, Tsiuri Phkhakadze, Besarion Tsikhelashvili
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The article dealt with the South Caucasus is a complex economic policy, which consists of strands: The process of deepening economic integration in the South Caucasus region; deepening economic integration with the EU in the framework of "Neighbourhood policy with Europe" and in line with the Maastricht criteria; the development of bilateral trade and economic relations with many countries of the world community; the development of sufficient conditions for the integration of the South Caucasus region in the world to enter the market. According to the author, to determine the place of Georgia in the regional policy of the South Caucasus, it is necessary to consider two views about Georgia: The first is the view of Georgia, as a part of global economic and political processes and the second look at Georgia, as a country located in the geo-economic and geopolitical space of the South Caucasus. Such approaches reveal the place of Georgia in two dimensions; in the global and regional economies. In the countries of South Caucasus, the tourism has been developing fast and has a great social and economic importance. Tourism influences deeply on the social and economic growth of the regions of the country. Tourism development formulates thousand new jobs, fixes the positions of small and middle businesses, ensures the development of the education and culture of the population. In the countries of South Caucasus, the Tourist Industry can be specified as the intersectoral complex, which consists of travel transport and it’s technical service network, tourist enterprises which are specialized in various types, wide network services. Tourists have a chance to enjoy all of these services. At the transitional stage of shifting to the market economy, tourism is among the priorities in the development of the national economy of our country. It is true that the Georgian tourism faces a range of problems at present, but its recognition and the necessity for its development may be considered as a fact. Besides, we would underline that the revitalization of the Georgian tourism is not only the question of time. This area can bring a lot of benefits as to private firms, as to specific countries. It also has many negative effects were conducted fundamental research and studies to consider both, positive and negative impacts of tourism. In the future such decisions will be taken that will bring, the maximum benefit at minimum cost, in order for tourism to take its place in Georgia it is necessary to understand the role of the tourism sector in the economic structure.Keywords: transitional stage, national economy, Georgian tourism, positive and negative impacts
Procedia PDF Downloads 3974802 Simulation of Welded Steel Tube Subjected to Internal Pressure
Authors: H. Zedira, M. T. Hannachi, H. Djebaili, B. Daheche
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The rapid pace of technology development and strong competition in the market, prompted us to consider the field of manufacturing of steel pipes by a process complies fully with the requirements of industrial induction welding is high frequency (HF), this technique is better known today in Algeria, more precisely for the manufacture of tubes diameters Single Annabib TG Tebessa. The aim of our study is based on the characterization of processes controlling the mechanical behavior of steel pipes (type E24-2), welded by high frequency induction, considering the different tests and among the most destructive known test internal pressure. The internal pressure test is performed according to the application area of welded pipes, or as leak test, either as a test of strength (bursting). All tubes are subjected to a hydraulic test pressure of 50 bar kept at room temperature for a period of 6 seconds. This study provides information that helps optimize the design and implementation to predict the behavior of the tubes during operation.Keywords: castem, pressure, stress, tubes, thickness
Procedia PDF Downloads 3264801 Abating the Barriers to the Deployment of RFID for Construction Project Delivery in South Africa
Authors: Matthew O. Ikuabe, Ayodeji E. Oke, Clinton O. Aigbavboa, Douglas O. Aghimien
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The use of technological innovations have been touted to be beneficial in the delivery of construction projects. Particularly, Radio Frequency Identification (RFID) technology is widely regarded to be of immense advantage for the management of construction projects. This study focused on evaluating the barriers to the use of Radio Frequency Identification (RFID) technology for the delivery of construction projects. Using Gauteng Provincein South Africa as the study area, questionnaire was used in eliciting responses from construction professionals, which made up the population of the study. Retrieved data was analysed using Mean Item Score and One-Sample t-test. Findings from the study showed that the most significant barriers to the deployment of RFID for construction project delivery are high cost and lack of awareness. Conclusively, the study made recommendations that would aid in the abatement of the barriers to the use of RFID technology for construction project delivery.Keywords: barriers, construction, project delivery, RFID
Procedia PDF Downloads 2064800 150 KVA Multifunction Laboratory Test Unit Based on Power-Frequency Converter
Authors: Bartosz Kedra, Robert Malkowski
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This paper provides description and presentation of laboratory test unit built basing on 150 kVA power frequency converter and Simulink RealTime platform. Assumptions, based on criteria which load and generator types may be simulated using discussed device, are presented, as well as control algorithm structure. As laboratory setup contains transformer with thyristor controlled tap changer, a wider scope of setup capabilities is presented. Information about used communication interface, data maintenance, and storage solution as well as used Simulink real-time features is presented. List and description of all measurements are provided. Potential of laboratory setup modifications is evaluated. For purposes of Rapid Control Prototyping, a dedicated environment was used Simulink RealTime. Therefore, load model Functional Unit Controller is based on a PC computer with I/O cards and Simulink RealTime software. Simulink RealTime was used to create real-time applications directly from Simulink models. In the next step, applications were loaded on a target computer connected to physical devices that provided opportunity to perform Hardware in the Loop (HIL) tests, as well as the mentioned Rapid Control Prototyping process. With Simulink RealTime, Simulink models were extended with I/O cards driver blocks that made automatic generation of real-time applications and performing interactive or automated runs on a dedicated target computer equipped with a real-time kernel, multicore CPU, and I/O cards possible. Results of performed laboratory tests are presented. Different load configurations are described and experimental results are presented. This includes simulation of under frequency load shedding, frequency and voltage dependent characteristics of groups of load units, time characteristics of group of different load units in a chosen area and arbitrary active and reactive power regulation basing on defined schedule.Keywords: MATLAB, power converter, Simulink Real-Time, thyristor-controlled tap changer
Procedia PDF Downloads 3234799 The Survey Research and Evaluation of Green Residential Building Based on the Improved Group Analytical Hierarchy Process Method in Yinchuan
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Due to the economic downturn and the deterioration of the living environment, the development of residential buildings as high energy consuming building is gradually changing from “extensive” to green building in China. So, the evaluation system of green building is continuously improved, but the current evaluation work has the following problems: (1) There are differences in the cost of the actual investment and the purchasing power of residents, also construction target of green residential building is single and lacks multi-objective performance development. (2) Green building evaluation lacks regional characteristics and cannot reflect the different regional residents demand. (3) In the process of determining the criteria weight, the experts’ judgment matrix is difficult to meet the requirement of consistency. Therefore, to solve those problems, questionnaires which are about the green residential building for Ningxia area are distributed, and the results of questionnaires can feedback the purchasing power of residents and the acceptance of the green building cost. Secondly, combined with the geographical features of Ningxia minority areas, the evaluation criteria system of green residential building is constructed. Finally, using the improved group AHP method and the grey clustering method, the criteria weight is determined, and a real case is evaluated, which is located in Xing Qing district, Ningxia. A conclusion can be obtained that the professional evaluation for this project and good social recognition is basically the same.Keywords: evaluation, green residential building, grey clustering method, group AHP
Procedia PDF Downloads 3974798 Transit Network Design Problem Issues and Challenges
Authors: Mahmoud Owais
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Public Transit (P.T) is very important means to reduce traffic congestion, to improve urban environmental conditions and consequently affects people social lives. Planning, designing and management of P.T are the key issues for offering a competitive mode that can compete with the private transportation. These transportation planning, designing and management issues are addressed in the Transit Network Design Problem (TNDP). It deals with a complete hierarchy of decision making process. It includes strategic, tactical and operational decisions. The main body of TNDP is two stages, namely; route design stage and frequency setting. The TNDP is extensively studied in the last five decades; however the research gate is still widely open due to its many practical and modeling challenges. In this paper, a comprehensive background is given to illustrate the issues and challenges related to the TNDP to help in directing the incoming researches towards the untouched areas of the problem.Keywords: frequency setting, network design, transit planning, urban planning
Procedia PDF Downloads 3844797 Proposals of Exposure Limits for Infrasound From Wind Turbines
Authors: M. Pawlaczyk-Łuszczyńska, T. Wszołek, A. Dudarewicz, P. Małecki, M. Kłaczyński, A. Bortkiewicz
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Human tolerance to infrasound is defined by the hearing threshold. Infrasound that cannot be heard (or felt) is not annoying and is not thought to have any other adverse or health effects. Recent research has largely confirmed earlier findings. ISO 7196:1995 recommends the use of G-weighted characteristics for the assessment of infrasound. There is a strong correlation between G-weighted SPL and annoyance perception. The aim of this study was to propose exposure limits for infrasound from wind turbines. However, only a few countries have set limits for infrasound. These limits are usually no higher than 85-92 dBG, and none of them are specific to wind turbines. Over the years, a number of studies have been carried out to determine hearing thresholds below 20 Hz. It has been recognized that 10% of young people would be able to perceive 10 Hz at around 90 dB, and it has also been found that the difference in median hearing thresholds between young adults aged around 20 years and older adults aged over 60 years is around 10 dB, irrespective of frequency. This shows that older people (up to about 60 years of age) retain good hearing in the low frequency range, while their sensitivity to higher frequencies is often significantly reduced. In terms of exposure limits for infrasound, the average hearing threshold corresponds to a tone with a G-weighted SPL of about 96 dBG. In contrast, infrasound at Lp,G levels below 85-90 dBG is usually inaudible. The individual hearing threshold can, therefore be 10-15 dB lower than the average threshold, so the recommended limits for environmental infrasound could be 75 dBG or 80 dBG. It is worth noting that the G86 curve has been taken as the threshold of auditory perception of infrasound reached by 90-95% of the population, so the G75 and G80 curves can be taken as the criterion curve for wind turbine infrasound. Finally, two assessment methods and corresponding exposure limit values have been proposed for wind turbine infrasound, i.e. method I - based on G-weighted sound pressure level measurements and method II - based on frequency analysis in 1/3-octave bands in the frequency range 4-20 Hz. Separate limit values have been set for outdoor living areas in the open countryside (Area A) and for noise sensitive areas (Area B). In the case of Method I, infrasound limit values of 80 dBG (for areas A) and 75 dBG (for areas B) have been proposed, while in the case of Method II - criterion curves G80 and G75 have been chosen (for areas A and B, respectively).Keywords: infrasound, exposure limit, hearing thresholds, wind turbines
Procedia PDF Downloads 834796 Frequency Recognition Models for Steady State Visual Evoked Potential Based Brain Computer Interfaces (BCIs)
Authors: Zeki Oralhan, Mahmut Tokmakçı
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SSVEP based brain computer interface (BCI) systems have been preferred, because of high information transfer rate (ITR) and practical use. ITR is the parameter of BCI overall performance. For high ITR value, one of specification BCI system is that has high accuracy. In this study, we investigated to recognize SSVEP with shorter time and lower error rate. In the experiment, there were 8 flickers on light crystal display (LCD). Participants gazed to flicker which had 12 Hz frequency and 50% duty cycle ratio on the LCD during 10 seconds. During the experiment, EEG signals were acquired via EEG device. The EEG data was filtered in preprocessing session. After that Canonical Correlation Analysis (CCA), Multiset CCA (MsetCCA), phase constrained CCA (PCCA), and Multiway CCA (MwayCCA) methods were applied on data. The highest average accuracy value was reached when MsetCCA was applied.Keywords: brain computer interface, canonical correlation analysis, human computer interaction, SSVEP
Procedia PDF Downloads 2664795 A Neurofeedback Learning Model Using Time-Frequency Analysis for Volleyball Performance Enhancement
Authors: Hamed Yousefi, Farnaz Mohammadi, Niloufar Mirian, Navid Amini
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Investigating possible capacities of visual functions where adapted mechanisms can enhance the capability of sports trainees is a promising area of research, not only from the cognitive viewpoint but also in terms of unlimited applications in sports training. In this paper, the visual evoked potential (VEP) and event-related potential (ERP) signals of amateur and trained volleyball players in a pilot study were processed. Two groups of amateur and trained subjects are asked to imagine themselves in the state of receiving a ball while they are shown a simulated volleyball field. The proposed method is based on a set of time-frequency features using algorithms such as Gabor filter, continuous wavelet transform, and a multi-stage wavelet decomposition that are extracted from VEP signals that can be indicative of being amateur or trained. The linear discriminant classifier achieves the accuracy, sensitivity, and specificity of 100% when the average of the repetitions of the signal corresponding to the task is used. The main purpose of this study is to investigate the feasibility of a fast, robust, and reliable feature/model determination as a neurofeedback parameter to be utilized for improving the volleyball players’ performance. The proposed measure has potential applications in brain-computer interface technology where a real-time biomarker is needed.Keywords: visual evoked potential, time-frequency feature extraction, short-time Fourier transform, event-related spectrum potential classification, linear discriminant analysis
Procedia PDF Downloads 1384794 The Use of Nuclear Generation to Provide Power System Stability
Authors: Heather Wyman-Pain, Yuankai Bian, Furong Li
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The decreasing use of fossil fuel power stations has a negative effect on the stability of the electricity systems in many countries. Nuclear power stations have traditionally provided minimal ancillary services to support the system but this must change in the future as they replace fossil fuel generators. This paper explains the development of the four most popular reactor types still in regular operation across the world which have formed the basis for most reactor development since their commercialisation in the 1950s. The use of nuclear power in four countries with varying levels of capacity provided by nuclear generators is investigated, using the primary frequency response provided by generators as a measure for the electricity networks stability, to assess the need for nuclear generators to provide additional support as their share of the generation capacity increases.Keywords: frequency control, nuclear power generation, power system stability, system inertia
Procedia PDF Downloads 4374793 System Identification of Timber Masonry Walls Using Shaking Table Test
Authors: Timir Baran Roy, Luis Guerreiro, Ashutosh Bagchi
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Dynamic study is important in order to design, repair and rehabilitation of structures. It has played an important role in the behavior characterization of structures; such as bridges, dams, high-rise buildings etc. There had been a substantial development in this area over the last few decades, especially in the field of dynamic identification techniques of structural systems. Frequency Domain Decomposition (FDD) and Time Domain Decomposition are most commonly used methods to identify modal parameters; such as natural frequency, modal damping, and mode shape. The focus of the present research is to study the dynamic characteristics of typical timber masonry walls commonly used in Portugal. For that purpose, a multi-storey structural prototypes of such walls have been tested on a seismic shake table at the National Laboratory for Civil Engineering, Portugal (LNEC). Signal processing has been performed of the output response, which is collected from the shaking table experiment of the prototype using accelerometers. In the present work signal processing of the output response, based on the input response has been done in two ways: FDD and Stochastic Subspace Identification (SSI). In order to estimate the values of the modal parameters, algorithms for FDD are formulated, and parametric functions for the SSI are computed. Finally, estimated values from both the methods are compared to measure the accuracy of both the techniques.Keywords: frequency domain decomposition (fdd), modal parameters, signal processing, stochastic subspace identification (ssi), time domain decomposition
Procedia PDF Downloads 264