This paper presents performance features of Symmetric and Asymmetric Cascaded Multilevel inverter. Multilevel inverters are commonly modulated by using multicarrier pulse width modulation (MCPWM) techniques such as phase-shifted multicarrier modulation and level-shifted multicarrier modulation. Amongst these level-shifted multicarrier modulations technique produces the best harmonic performance. This work studies about multilevel inverter with equal and unequal DC sources using level shifting MCPWM technique. The Performances indices like Total Harmonic Distortion (THD), reduction of switches and number of DC Sources are considered. A procedure to achieve the appropriate level shifting is also presented is this paper.
This paper presents a new fault classification strategy for transmission lines based on fuzzy logic. The ranking procedure uses the three phase current amplitudes and the current symmetrical components during the fault appearance phase. The suggested technique is able to classify all possible faults to know phase-ground, phase-phase, phase-phase-ground and three-phase with a high accuracy degree. The proposed method is evaluated under several fault conditions such as the inception angle, the fault resistance, the fault location and load angle. Thus, simulations under MATLAB environment were made on a 400KV transmission line. Simulation results confirm the effectiveness of our approach to be used like accuracy mean for the fault classification.
One of the key challenges of Service Oriented Architecture (SOA) is the discovery of relevant Web Services for a given task. As Web services proliferate, there is a possibility of existence of more than one service with same functionalities consequently; any service discovery method will return several services which meet user given input and output. Finding the most relevant and best service is very crucial for the service consumers. In this situation, the nonfunctional Quality of Service (QoS) parameters present in the service description provided by the service provider play a major role. In this paper, a novel approach is proposed which uses the belief net to intelligently infer the best and most relevant web service based on the available QoS parameters.
The PMSM drives are most suitable for high performance adjustable speed AC drives. These drives have an important role in realizing servo mechanisms for computer numerically controlled machine made tools, robots in industries and actuators. In the industry where the machine tools are made the heat lost in the rotor part of the machine drives affect the machine tools and work pieces and the machining operation. Thus, due to negligible rotor losses compared to other servo drives PMSM motor has wide scope in the machining operations. Advantages of PMSM drives over other drives are higher power factor operation, higher torque to inertia ratio and higher efficiency inverter. The survey of PMSM motor under various techniques is taken. We strongly believe that this survey article will be very much useful to the researchers for finding out the relevant references in the field of topologies used in PMSM motor.
The need for communications networks is quite evident in the world today, multicasting has becomes a major way of transferring digital data to huge number of audience. The advantages of multicast in multi-party communications, such as saving bandwidth, simplicity and efficiency, are very essential for new services that combine voice, video and text over Internet. It has many applications in online multimedia and sensor networks and so on. The multicast networks distribute sensitive or private information, therefore they must be provided via secure communication channels. In this paper, the security of multicast network has been reviewed. A method has been presented to improve the security of multicast network (SMN) using quantum key distribution (QKD) network. This technique protected multicast network against internal and external impersonation. The QKD has been added to multicast network architecture to generate the secure keys. The keys are in the authentication and encryption processes. The proposed scheme aimed to provide a secure end to end communication for multicast network.
This study presents a speed controller design for a switched reluctance (SR) motor in order to achieve minimum torque ripple and high control performance. First of all, SR motor convertor designed for soft chopping is chosen. This converter as well as producing less torque ripple, provides more degrees of freedom for SR motor drive controller. A PID controller and a switching algorithm for turn-on and turn-off degree of each phase of motor form speed control loop of SR motor drive. The primary parameters of controller are achieved by trial and error. But eventually an optimization algorithm to reach the goals and constraints in different set points is defined and its parameters are optimized with a Genetic Algorithm (GA). This algorithm optimized the turn-on and turn-off degrees of each phase, the parameters of PID controller in transient state, and parameters of PID controller that considered for reducing the torque ripple in steady state. Also, GA simultaneously obtains the optimum parameters of three nonlinear gains considered for switching between the two PID controllers. The proposed control algorithm was simulated using MATLAB / Simulink software package and an application example of 6/4 SRM to validate the performance of designed algorithm
In this study safflower oil was transesterified with methanol using sodium hydroxide as catalyst to obtain safflower methyl ester. Biodiesel was blended with petroleum diesel in different proportion. Engine emission and the performance of the blends were measured and evaluated for the compression ignition, direct injection diesel engine. Safflower methyl ester and its blend can be successfully used in diesel without any engine modification. Engine Performance and exhaust emission is improved in Lower concentration of methyl ester blends. Lower percentage of safflower methyl ester is used as biodiesel
Reproduction is the single greatest factor limiting beef cattle production. The study was conducted to determine the influence of season on postpartum serum concentration of follicle stimulating hormone (FSH), oestradiol 17 β and progesterone was studied using 130 cyclic montberliard. Four groups of cows were studied: autumn (n = 41), winter (n = 24), spring (n = 33) and summer (n = 32) cows. Hormonal concentration was determined by a radio immune assay (RIA). Hormonal concentration was measured in serum samples taken 30, 40 and 50 days post partum, in 130 animals, over two years. Onset of luteal activity was defined as the progesterone concentration exceeded 1 ng/ml. The analysis of mean circulating hormone concentrations of FSH, progesterone and estradiol 17β were increased by stage postpartum (P< 0,000) revealed resumption of follicular wave dynamics and corpora lutea activity in postpartum period. Furthermore, our recent investigations on endocrine changes associated with cyclicity commencement in montberliard breed were affected (P< 0,000) by calving season. In conclusion, our data strongly support the concept that season of calving influenced reproductive hormonal profile and the percentage of cows that resumed ovarian cyclicity postpartum at different postpartum intervals under semi-arid area of Algeria. \nKeywords: postpartum; luteal activity; FSH, RIA; progesterone profile; montbelaird; season; semi-arid.
In the present day scenario, the whole genome sequence for an increasing number of species available in the public domain from different databases. The other side, still a huge amount of study is going on to find the species from the given piece of DNA sequence. Instead of analyzing the entire sequence of DNA code from the beginning to end to find the classification of the species, the author is proposing architecture to find the species with fewer efforts. In this architecture the author will train the neural network with the existing species knowledge. By giving the unknown sequence of code to this trained model the author will reach the conclusion with fewer steps and efforts. In this paper the author is proposing an abstract architecture model to incorporate datamining and neural network technique which is coined as Neural Mining (NM) for species classification.
Recently, biometric identification using gait signals as a biometric trait plays a vital role in the field of security surveillances. Human gait deals with the principle of recognizing the people by the way of their walking style. In this paper, the Gaussian Mixture Model (GMM) isolates the moving object and the relevant features are extracted using Principal Component Analysis (PCA). The extracted features are trained by Fisher’s Linear Discriminant Analysis Classifier (FLDA), to classify the foreground objects from the video stream. Experimental results conducted on CASIA gait database, USF gait database and real database of video sequences shows that the proposed method increases the recognition rate.
Abstract\nPurpose: The amount of imaging data is rapidly increasing, due to the widespread dissemination of picture archiving and communication systems (PACS) in hospitals. Effective image retrieval systems are required to manage these complex and large image databases. Medical images are often deteriorated by noise due to various sources of interferences and other phenomena. This paper presents a novel way to choose an appropriate filter suitable for noise removal in medical image processing and to implement content based image retrieval (CBIR) system that uses fuzzy based concept for identifying the similar image to that of a submitted query image.\nMethods: There are several methodologies in CBIR systems; fuzzy based retrieval is one of the kinds that aids in a more accurate diagnosis of the disease. This is done by providing a system that would employ a fuzzy based strategy for better comparison and thereby help in identifying a close match to the submitted query image\nResults: The main idea in this paper is to identify the desirable filter based on some of the performance metrics and to employ fuzzy logic in categorization and retrieval of similar images. Fuzzy based systems are more accurate in comparison to other systems since they deal with the imprecision in data in a better way.\nConclusion: The proposed system will therefore serve to be a reliable method of retrieval and help in building a tool for more accurate and efficient diagnosis of liver images.\nKeywords: Content-based image retrieval, Pathological liver, Noise removal, Filter, Fuzzy Logic.
This paper reports a novel four-dimensional energy resource system with government regulation. The system is obtained in accordance with the complicated relationship between energy demands, energy supply, government regulation and new energy development. The novel four-dimensional system can generate multilayer chaotic attractor by choosing different parameters. The dynamics behavior of the system will be analyzed by means of Lyapunov exponents and equilibrium. Linear feedback control methods are used to suppress chaos to unstable equilibrium. Numerical simulations are presented to show these results.
Several researches cited that both of the capital asset pricing approaches (CAPM & APT) did not emphasis on the explanation of the relation of risk and return, or immeasurable market portfolio. Included, the dividend capitalization model (DCM) based traditional estimate does not effective for the firm that has no dividend policy. The purposes of this literature are to propose the alternative estimation of the cost of equity which this quantity becomes an important variable for the intrinsic worth valuation model. Its format can be express interchangeably in many forms of accounting numbers and some financial ratios. The proposed model can eliminate the drawbacks of existing estimations and also explainable why investors are still investing in shares of a firm that has no dividend policy. While traditional estimation methods are lacking the explanation of this truth.
A graph is a good way to illustrate some relations between things. A general-graph is a new type of graphs which has a lot of properties. So, in this paper we will define new types of foldings of general-graphs. Theorems that governing these types of foldings will be deduced.
In Wireless Network Routing, the static shortest path (SP) problem has been addressed using well known intelligent optimization techniques like Genetic Algorithms (GAs), Particle Swarm Optimization (PSO) and Artificial Bee Colony (ABC). However in Mobile Ad Hoc Network (MANET) mobile nodes moving dynamically. Therefore, the SP routing problem in MANET turns into dynamic optimization problem (DOP). Here the nodes are made aware of the environmental condition, thereby making it intelligent. Intelligent analysis and designing of network routing provides an edge in this increasingly fast era. Routing is one the most important issue that has a significant impact on the networks performance. Therefore, the SP problem turns out to be a Dynamic Optimization Problem (DOP) in MANETs. In this paper, we propose to use Artificial Bee Colony optimization algorithm (ABC) to solve the DSP problem in MANETs. We consider that MANETs as target systems because they represent next generation wireless networks. The experimental results show that the ABC can quickly adapt to the environmental changes (i.e., the network topology dynamically changes) and it find the shortest path easily.
Abstract: The study was conducted to investigate the challenges faced by the small scale industrial promoters while managing the business. Ascertaining the first hand opinion on various challenges faced by the Small Scale Industries (SSI) was the major focus of the study. The study was carried out in ten selected districts in Tamil Nadu. In the study opinion from 500 small scale producers were taken by using structured questionnaire and unstructured interview for analysis. The results received from chi-square and ANNOVA tests reveals that challenges faced by the SSI vary with the type of the industry and comparatively the newly started organizations facing more challenges. Factors affecting marketing performance are same for SSIs in different geographical area with respect to Pricing Strategy and Competitiveness. Agricultural and textile industries suffer more due to financial issues, capital, and space are the major challenges faced during expansion. Because of wide-spread electricity cut through the State SSIs suffered. The study recommends that the government should urgently address the electricity issue, as well as consider other suggestions also to rejuvenate SSI development and sustainability. This has become critical in view of the potentials of the SSI sector in entrepreneurship development, employment generation and wealth creation.\nKeywords: SSI, Challenges, Rejuvenate, Entrepreneurship, Employment.
This paper presents simulation results of four phase asymmetric converter for switched reluctance motor. Switched reluctance motor has advantages like reduced motor losses, high-speed operation and fast response. Four-phase asymmetric converter system is simulated and the corresponding results are presented.
Purpose: Inpatient and office-based anesthesia is major component of dentistry. Pharmacologic agents are being more commonly used to diminish pain and anxiety during dental procedures. Propofol is such an agent used frequently in dental anesthesia. Here, the authors aimed to document their experience with propofol deep sedation in pediatric dental therapy.\nMethods: Pediatric patients who had dental therapy with sedation were reviewed. Propofol infusion with a rate of 75-100 µg/kg/min was initiated while the patient was spontaneously breathing with 4 l/min oxygen support. Patients were kept in recovery room and then discharged following the procedure.\nResults: 547 patients were included. 59.6% were male and 40.4% were female. Mean age was 6.01± 2.27 years. The complications observed were laryngospasm (10.0%), agitation (3.5%), and allergic reaction (0.7%). Intubation was required in 2.4%. Mean anesthesia time was 66.3 ± 24.2 minutes and mean recovery time was 36.6 ± 12.4 minutes. Postoperative nausea was more common in female patients with an odds ratio of 2.34.\nConclusion: For patients undergoing pediatric dentistry procedures, propofol is a safe, easily titratable anesthetic agent that provides early recovery. Awareness of minor complications that may lead to major ones is important to decrease side effects and complication rates.
In this research work, a gamma ray sensor (The Mole) was used to monitor the spatial variations of natural radionuclides concentration in the surface layer of cultivated soils at different regions in Saudi Arabia. The radionuclides of 40-K, 238-U, 232-Th and 137-Cs in Bq/kg were measured in-situ. The overall average value of specific activity concentration ratio of 232-Th/ 238-U was about 0.985 and it is slightly lower than the world’s average ratio, which is equal to unity. The results of this work are relatively consistent with the results obtained in other previous research works in Saudi Arabia. The concentration measurements of naturally-occurring radionuclides in soils are reported in this work and can be used as a reference data to evaluate any future change of radiation levels in the soil of the selected regions.
Compressed Sensing seeks to recover an unknown sparse signal with entries by making far fewer than measurements. The Restricted Isometry Property (RIP) has become a dominant tool used for such cases since if RIP satisfies some bound then sparse signals are guaranteed to be recovered exactly when no noise is present and sparse signals can be estimated stably in the noisy case. During the last few years, a great deal of attention has been focused on the bounds of RIP. The bounds of are 0.4142 in ; 0.4531 in ; 0.4652 in ; 0.4721 in ; 0.4734 in ; 0.4931 in . The bounds of are: Cai et al.  have proposed for any ; Ji and Peng  gave when is even. One of the main results of this paper obtains for any . Further, we discuss the problems related larger bound of RIP, and give the conditional maximum bound .
Falls among older adults are quite common, resulting in high mortality, morbidity, and utilization of health services. This review presents the current state of falls among older adults and discusses the main causes of falls in this population. Causes are grouped into biological, behavioral, and environmental risk factors. This review also outlines the injuries that result from these falls, and how these injuries negatively affect the lives of older adults. The impact on quality of life can be severe, especially in severe cases in which individuals sustain fractures, dislocations, head injuries, and sprains. Finally, preventive measures and interventions are reviewed, such as removing environmental hazards. All community and family members need to contribute to ensuring that older adults have homes and environments in which they can move about without risking falls.
The effect of mechanical and multi – step chemical treatments on the adsorptivity of rice husk adsorbent for the removal of 18 multi – heavy metal component from simulated wastewater was evaluated in this study. There are four types of rice husk adsorbents prepared for the adsorption studies, namely Raw Rice Husk, Blended Rice Husk, Acetone – Benzene Treated Rice Husk (ABRH) and Acetone – Benzene – Methanol Treated Rice Husk (ABMRH). The fixed bed column studies were also carried out under two different experimental rigs, which are single and multi layered fixed bed columns. It was found that, the adsorption of multi – heavy metal component was significantly increased in the following order: Raw Rice Husk (Single – Layered Bed) < Blended Rice Husk (Single – Layered Bed) < Blended Rice Husk (Multi – Layered Bed) < Acetone – Benzene Treated Rice Husk (Multi – Layered Bed) < Acetone – Benzene – Methanol Treated Rice Husk (Multi – Layered Bed). The highest percentage reduction of area under the graph was demonstrated by Acetone – Benzene – Methanol Treated Rice Husk under multi – layered fixed bed column by 94.49%. SEM examination suggested, it might be due to formation of T-shirt model of pore shape which having more porous area. This model also exhibited highest adsorption performance.
Machining of composite materials is an important and current topic in modern researches on manufacturing processes. In this paper study of drilling of Aluminium, Silicon Carbide (AlSiC) is investigated. The objective of this research is to study the effect of cutting speed, feed, diameter of cut, machining time on metal removal rate, specific energy, surface roughness, volume fraction and flank wear. This paper attempts to establish a comprehensive mathematical model for correlating the interactive and higher-order influences of various machining parameters using Taguchi method. Analysis of variance (ANOVA) has been performed to verify the fit and adequacy of the developed mathematical models. In the present work, a multiple regression model is used to represent relationship between input and output variables and a multi-objective optimization method based on a Genetic Algorithm (GA) is used to optimize the process. The second order polynomial equations were developed for all machining characteristics with the help of SPSS software. The models developed have been used for optimization of cutting parameters for the specified objective using genetic algorithms and non¬linear goal programming technique. The models developed can be used for predicting the characteristics studied and the optimized conditions can be used for better machinability of these aluminium matrix composites.\nKeywords: Laminated composite materials; Drilling processes; Multi-objective optimization; Genetic Algorithms; TaguchiMethod .
This paper deals with the hysteresis current control based hybrid shunt active filter to improve the power factor of a distribution line by minimizing the harmonics. The power factor and the harmonics of a 415V, 50 Hz distribution system supplying power for a computer laboratory are observed in real time. The non linear loads such as UPS take discontinuous current and thus it injects harmonics. The switching of loads produces voltage sag and swells which leads to harmonics in the lines. The hybrid shunt active filter characterized by series LC and shunt DC link connected through 3-phase active filter is proposed. The disturbances in the supply voltage and load current due to non linear load in the 415 V, 50 Hz distribution line is observed using CW240 power quality meter. The same is simulated in MATLAB with and without filter. The simulation results obtained from the proposed method proves that it gives comparatively better power factor.
Abstract \nIn order to determine correlation and path coefficient analysis of some seed quality traits in bread wheat, Ninety-two bread wheat genotypes were evaluated in alpha lattice design with two replication. Result of analysis of variance indicated that there were significant differences among genotypes in the majority of traits. The correlation analysis showed that there were extreme significant positive correlations among Thousand Kernel Weight (TKW), Grain Length (GL) and Grain Width (GW). TKW, GL and GW had positive correlated with Protein percentage, Gluten weight, and Falling number. Protein percentage was signiﬁcantly correlated with several kernel characteristics including: Hardness Index, Gluten weight, SDS Sedimentation, TKW, GL, GW and Falling Number. Path coefficient analysis also showed the direct and significant effects of protein percentage and medium direct effect of Falling number on SDS sedimentation.
Parental bonding consists of two dimensions: interest/control and excessive protection. Conflict resolution, which can be constructive or destructive, is important in the transition to adulthood. Examining the relationships between paternal bonding and problem solving can contribute to the relevant literature and provide information regarding the direction and intensity of the relationships between these variables. This research used the relational model. The participants—672 students studying at a university in Kırıkkale, Turkey—were chosen using the purposive sampling method. Problem Solving Scale and Parental Bonding Scale were used to gather the data. The results of the analysis indicate that paternal bonding affects both the constructive and destructive conflict resolution positively at a low level. These findings are discussed with respect to existing literature.
Generally Multi-agent systems consist of different kind of agents and are characterized by constant change or activity. These systems are open (exposed) to attack or view and there are individual features, among these features providing security becomes critical. So in order to avoid vulnerabilities, attacks and threats, we want to evaluate trust and reputation of all involved agents. When vulnerabilities act in an unexpected way, most of the existing systems fail to detect threats and cannot react immediately at oscillating time. Here we calculate the trust ability of all involved agents in the open network by using “Secured Trust” model. In this system, we first analyze the different factors related to evaluating the trust of an agent and then propose a comprehensive quantitative model for measuring such trust. The Load-Balancing algorithm is used to distribute the workload evenly
To propose a fault tolerant technique for an automotive embedded system using CAN controller and rough set classifiers. In a tightly coupled information system where the data dependency is high and embedded, the need for a strong mathematical model for fault tolerance in embedded system is needed. The system faults may be due to the constituent components including the hardware, application software and the operation environment at the target. The indiscernible relation is generated due to the lack of information about the correct functionality or behavior of the components in the system. The decision through FT CAN and reduction of attributes excluding the necessary redundant components enhance the detection capability. The rough set approximation theory with the fuzzy membership functions helps not only to remove the vagueness in the detection method but also to locate the faulty components.
Experimental study was carried out for optimizing the fluid inventory in a heat pipe. A heat pipe with 26.6 mm inner diameter, 893 mm length using metal screens with cotton wick was constructed tested with variable filling ratio of distillation water as working fluid for different thermal loads to assess the performance of heat pipe. The amount of distillation water was varied depending on the relationship proposed in the present work. Finally, optimum water filling ratio is 87% of the wick volume, where identified in terms of lower temperature difference between evaporator and condenser, lower thermal resistance and higher overall heat transfer coefficient. The relationship proposed in the present study compared with previous study, the comparison shows some difference in results. This may be regarded to the use cotton wick in present work.
Purpose:\nSpinal MR imaging is a frequently performed procedure. Radiologists usually concentrate on spinal findings and extraspinal findings can be overlooked. Some of the incidental help explaining the symptoms while others give the option of early diagnosis.\n\nMethods and Procedures:\nSpinal MR imaging reports of 3398 patient were retrospectively reviewed and incidental extraspinal findings cited in the reports were tabulated. \n\nResults:\n4962 (1272 cervical, 214 thoracic and 3476 lumbar) spinal MR imaging reports were reviewed. A total of 301 incidental anomalies were detected in 6% of the cases. The most common incidental findings were the genitourinary pathologies, renal and ovarian cysts making the biggest contribution.\n\nConclusions:\nVarious extraspinal pathologies are detected on spinal MR imaging reports. It is crucial not to focus only on the spinal canal but to analyse from a broader perspective. Some of the incidental findings are more crucial than the suspected pathology. Picture archiving and communication system (PACS) enables access to localizer series, uncropped images with a larger field of view. Broader installation of PACS will potentially increase the number of reported incidental findings.\n\nKeywords: MR imaging, spinal, incidental, extraspinal
Limited battery life in ad hoc network has received more attention because of its important role in topology infrastructure, route finding and diffusing data. This study attempted to propose a new energy minimization algorithm based on intelligent broadcasting protocols. Particle Swarm Optimization algorithm (PSO) for better tabling information to optimize route in case of any congestion and select short path. The effect of network topology and traffic parameters were also taken into account for the broadcast storm problem. The simulation results show the effectiveness of the proposed algorithm to improve the network performance in term of reception rates and lower message travel time.
Increasing population and global climate change are making the situation more serious. Increasing water use efficiency in irrigated agriculture and promotion of dry land farming will both play a significant role in maintaining food security. The objective of this investigation was to study the overall impact of pre-harvest drought periods and potassium (K) fertilization rates on water use efficiency and productivity of a sugar beet crop. This investigation was conducted during the 2009/2010 and 2010/2011 growing seasons at the experimental farm of the El-Karada water management Research Station (31°05’ N and 30°56’ E), Kafr El-Sheikh Governorate, North Delta, Egypt. A split plot design with four replicates was used. The main plot included pre-harvest drought periods of three, six and nine weeks, and sub-plot included K fertilization rates of 0, 114 and 171 kg K2O.ha-1. A pre-harvest drought period of 9 weeks achieved the highest average values of crop water use efficiency (16.77 kg root.m-3), field water use efficiency (11.37 kg root.m-3), juice purity of sugar beet (75.79%) and sucrose percentage (19.56%). Maximum average values of root and gross sugar yields (78.4 and 15 ton ha-1, respectively) were achieved with a pre-harvest drought period of 6 weeks. For both growing seasons, K fertilization had a highly significant effect. A rate of 171 kg K2O ha-1 resulted in the highest root and sugar yields, crop water use efficiency, field water use efficiency, sucrose percentage, and juice purity. A K fertilization rate of 171 kg K2O ha-1 and a pre-harvest drought period of 6 weeks achieved the highest sugar and gross sugar yields for the sugar beet crop, saved about 19.52 % of applied irrigation water and minimized soil alkalinity and salinization.
To understand the genetic and molecular mechanisms of flowering in hickory (Carya cathayensis Sarg.), the 1,345-bp CcLFY promoter was cloned, which containing basic cis-acting elements related to environment and hormone. Similar TATA-box and CAAT-box motifs were located at -86 bp and -252 bp respectively. However, deletion of these motifs did not block β-glucuronidase (GUS) activity, suggesting that it may be a TATA-less promoter. The trans-regulatory factor binding sites were from -1302 bp to -958 bp and -592 bp to -315 bp using transient expression experiments in tobacco. A sequence located at -151 bp in the 5’-flanking region may substitute for the TATA-box. Both low temperature and light significantly induced the full-length promoter to increase GUS enzymatic activity from 8.93 to 17.77, and 8.93 to 18.24 nmol MU min-1 mg-1 respectively, which suggests these environments induce flowering in hickory.
This paper describes about the design and implementation of a Matrix Converter (MC) for adjustable speed drives. It presents the performance of a Single Phase Matrix Converter (SPMC) for variable voltage variable frequency applications. The single phase matrix converter is a single stage converter without any intermediate Direct Current (DC) link. The matrix converter needs four bidirectional switches to convert fixed frequency fixed voltage Alternating Current (AC) to variable frequency variable voltage AC. The simulation and the experimental results confirms that the matrix converter with simple Sinusoidal Pulse Width Modulation (SPWM) technique can provide the variable frequency output for the fixed frequency input supply with reduced harmonic content.
Tiling and tile-making art, which has been mostly used for decorating Iran’ architecture -especially in the religious buildings-, has special characteristics like Pottery. From the distant past, this art was manifested in the form of a synthetic object as a result of the craftsmanship, the taste and the sense of the tile-maker, thus the artist achieved different harmonic forms by using and blending various colors or by putting together the tiny particles of the colorful stones based on a predesigned plan. As the tiling art began in the Achaemenid period until the late Islamic era, this art has been through many ups and downs. Its climax of development was in the Ilkhani, Timurid and Safavid eras. Qajarid tiling evolves under the impact of previous eras and the Western countries’ tiling, which shows the importance of studying this art in the Qajarid era.