242 research outputs found

    Asymmetrical Nine-Level Inverter Topology with Reduce Power Semicondutor Devices

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    In this paper a new single-phase multilevel inverter topology is presented. Proposed topology is capable of producing nine-level output voltage with reduce device counts. It can be achieved by arranging available switches and dc sources in a fashion such that the maximum combination of addition and subtraction of the input dc sources can be obtained. To verify the viability of the proposed topology, the circuit model is developed and simulated in Matlab-Simulink software. Experimental testing results of the proposed nine-level inverter topology, developed in the laboratory, are presented. A low frequency switching strategy is employed in this work. The results show that the proposed topology is capable to produce a nine-level output voltage, capable in handling inductive load and yields acceptable harmonic distortion conten

    myBas driving cycle for Kuala Terengganu city

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    Driving cycles are series of data points that represent vehicle speed versus time sequenced profile developed for specific road, route, city or certain location. It is widely utilized in the application of vehicle manufacturers, environmentalists and traffic engineers. Since the vehicles are one of the higher air pollution sources, driving cycle is needed to evaluate the fuel consumption and exhaust emissions. The main objectives in this study are to develop and characterize the driving cycle for myBAS in Kuala Terengganu city using established k-means clustering method and to analyse the fuel consumption and emissions using advanced vehicle simulator (ADVISOR). Operation of myBAS offers 7 trunk routes and one feeder route. The research covered on two operation routes of myBAS which is Kuala Terengganu city-feeder and from Kuala Terengganu to Jeti Merang where the speed-time data is collected using on-board measurement method. In general, driving cycle is made up of a few micro-trips, defined as the trip made between two idling periods. These micro-trips cluster by using the k-means clustering method and matrix laboratory software (MATLAB) is used in developing myBAS driving cycle. Typically, developing the driving cycle based on the real-world in resulting improved the fuel economy and emissions of myBAS

    Review on decomposed fuzzy PID structure for power inverters regulation

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    The aim of this paper is to critically review prominent decomposed Fuzzy PID control structures. Structural construction and output control laws of these controllers will be discussed. Their merits and drawbacks are highlighted. Based on the critical discussions, a new structure of Fuzzy PID controller is proposed. It is based on cascaded structure, which yields simpler design flow and parameters tuning. Other advantages of the proposed Fuzzy PID structure are the reduction of tuning parameters and rules of the Fuzzy controller. In addition, the proposed structure allows the usage of signed distance method. The application of the method reduces the computation burden significantly as the power inverter regulation needs very fast and precise computation

    1,2-Bis[N′-(2,2-dimethyl­propionyl)thio­ureido]cyclo­hexa­ne

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    In the title compound, C18H32N4O2S2, the dihedral angle between the two thio­urea groups is 78.55 (7)°. The mol­ecular conformation is stabilized by intra­molecular N—H⋯O hydrogen bonds and the crystal structure is stabilized by inter­molecular N—H⋯O and C—H⋯O hydrogen bonds, forming centrosymmetric dimers

    On insertion-deletion systems over relational words

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    We introduce a new notion of a relational word as a finite totally ordered set of positions endowed with three binary relations that describe which positions are labeled by equal data, by unequal data and those having an undefined relation between their labels. We define the operations of insertion and deletion on relational words generalizing corresponding operations on strings. We prove that the transitive and reflexive closure of these operations has a decidable membership problem for the case of short insertion-deletion rules (of size two/three and three/two). At the same time, we show that in the general case such systems can produce a coding of any recursively enumerable language leading to undecidabilty of reachability questions.Comment: 24 pages, 8 figure

    Enhanced Photocatalytic Performance of NiO-Decorated ZnO Nanowhiskers for Methylene Blue Degradation

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    ZnO nanowhiskers were used for photodecomposition of methylene blue in aqueous solution under UV irradiation. The rate of methylene blue degradation increased linearly with time of UV irradiation. 54% of degradation rate was observed when the ZnO nanowhiskers were used as photocatalysts for methylene blue degradation for 80 min under UV irradiation. The decoration of ptype NiO nanoparticles on n-type ZnO nanowhiskers significantly enhanced photocatalytic activity and reached 72% degradation rate of methylene blue by using the same method. NiO-decorated ZnO was recycled for second test and shows 66% degradation from maximal peak of methylene blue within the same period. The increment of photocatalytic activity of NiO-decorated ZnO nanowhiskers was explained by the extension of the electron depletion layer due to the formation of nanoscale p-n junctions between p-type NiO and n-type ZnO. Hence, these products provide new alternative proficient photocatalysts for wastewater treatment

    Applications of artificial intelligence in ship berthing: A review

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    Ship berthing operations in restricted waters such as ports requires the accurate use of onboard-vessel equipment such as rudder, thrusters, and main propulsions. For big ships, the assistance of exterior supports such as tugboats are necessary, however with the advancement of technology, we may hypothesize that the use of artificial intelligence to support ship berthing safely at ports without the dependency on the tugboats may be a reality. In this paper we comprehensively assessed and analyzed several literatures regarding this topic. Through this review, we seek out to present a better understanding of the use of artificial intelligence in ship berthing especially neural networks and collision avoidance algorithms. We discovered that the use of global and local path planning combined with Artificial Neural Network (ANN) may help to achieve collision avoidance while completing ship berthing operations

    Applications of artificial intelligence in ship berthing: A review

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    855-863Ship berthing operations in restricted waters such as ports requires the accurate use of onboard-vessel equipment such as rudder, thrusters, and main propulsions. For big ships, the assistance of exterior supports such as tugboats are necessary, however with the advancement of technology, we may hypothesize that the use of artificial intelligence to support ship berthing safely at ports without the dependency on the tugboats may be a reality. In this paper we comprehensively assessed and analyzed several literatures regarding this topic. Through this review, we seek out to present a better understanding of the use of artificial intelligence in ship berthing especially neural networks and collision avoidance algorithms. We discovered that the use of global and local path planning combined with Artificial Neural Network (ANN) may help to achieve collision avoidance while completing ship berthing operations

    Extensively used conventional and selected advanced maximum power point tracking techniques for solar photovoltaic applications: an overview

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    The lower output efficiency of the solar PV panel is due to the deviation of its operating point from the maximum power operation. And the change in the maximum power point (MPP) with the change in uncontrolled environmental conditions such as temperature and isolation make it difficult to withstand the MPP operation of the system. Different techniques and maximum power point tracking algorithms have been developed to address the issue. This paper presents a critical overview of widely used maximum power tracking techniques for photovoltaic system applications. Conventional, as well as advanced developed methods, which are less complex, robust and reliable, are discussed. However, some complexity occurs while selecting the appropriate MPPT method for a particular application. One of the contributions of this review article is to provide an outline for the selection of appropriate technique suitable for a particular application. Comparative analysis and classification of the selected MPPT methods based on various features such as type of control strategies, control variables, a converter circuit, and practical/commercial applications are presented. This review article is envisioned to serve as a useful reference for future MPPT users and PV system design engineers

    Lead Toxicity due to Ingestion of Lead-Contaminated Opium in a Patient Presenting with Motor Neuropathy and Upper Limb Paresis: A case report

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    Opium users may present with central or peripheral nervous system-related symptoms, gastrointestinal complications and anaemia; in such cases, lead poisoning should be suspected and chelation therapy initiated as soon as possible. We report a 64-year-old male patient with a 20-year history of opium addiction who was referred to the Imam Reza Hospital, Birjand, Iran, in 2017 with severe motor neuropathy and paresis in both upper limbs. His primary symptoms were generalised weakness, abdominal and bone pain, constipation and lower limb paraesthesia that had started several months prior. In addition, he reported severe progressive bilateral paresis of the upper limbs of one month’s duration. A diagnosis of lead poisoning was confirmed by a blood lead level of 140 μg/dL. The patient underwent chelation therapy after which he improved significantly. At a one-year follow-up visit, he was neurologically intact and symptom-free. Keywords: Opium Dependence; Lead Poisoning; Lead-Induced Nervous System Diseases; Paresthesia; Case Report; Iran
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