Optimized PID Controller of DC-DC Buck Converter based on Archimedes Optimization Algorithm

This research assesses the suitability of the Archimedes Optimization Algorithm (AOA) as a metaheuristic technique to fine-tune a PID controller in a closed-loop DC-DC buck converter. The converter's core function is to regulate output voltage, ensuring stability despite load fluctuations and input voltage changes.  The operational effectiveness of the converter hinges significantly on the gain settings of the PID controller and determining the optimal gain setting for the PID controller is a non-trivial task. For robust performance, the PID controller necessitates optimal gain settings, attainable through metaheuristic optimization. The algorithm aids in identifying ideal proportional, integral, and derivative gains based on varying load conditions. Leveraging the metaheuristic algorithm, the PID controller is optimized to minimize voltage errors, reduce overshoot, and enhance response time. The proposed PID controller, optimized using AOA, is contrasted with PID controllers tuned via alternative algorithms including the hybrid Nelder-Mead method (AEONM), artificial ecosystem-based optimization (AEO), differential evolution (DE), and particle swarm optimizer (PSO). Performance evaluation involves injecting a voltage disturbance into the buck converter with load changes of up to 20%. Results demonstrate the superiority of the AOA-optimized PID controller in voltage recovery.  It demonstrates a faster response time and outstanding voltage regulation performance, while also exhibiting minimal performance degradation during load changes. This study concludes that the AOA optimization algorithm surpasses other methods in tuning the PID controller for closed-loop DC-DC buck converters

Optimized PID controller of DC-DC buck converter based on archimedes optimization algorithm

This research assesses the suitability of the Archimedes Optimization Algorithm (AOA) as a metaheuristic technique to fine-tune a PID controller in a closed-loop DC-DC buck converter. The converter's core function is to regulate output voltage, ensuring stability despite load fluctuations and input voltage changes. The operational effectiveness of the converter hinges significantly on the gain settings of the PID controller and determining the optimal gain setting for the PID controller is a non-trivial task. For robust performance, the PID controller necessitates optimal gain settings, attainable through metaheuristic optimization. The algorithm aids in identifying ideal proportional, integral, and derivative gains based on varying load conditions. Leveraging the metaheuristic algorithm, the PID controller is optimized to minimize voltage errors, reduce overshoot, and enhance response time. The proposed PID controller, optimized using AOA, is contrasted with PID controllers tuned via alternative algorithms including the hybrid Nelder-Mead method (AEONM), artificial ecosystem-based optimization (AEO), differential evolution (DE), and particle swarm optimizer (PSO). Performance evaluation involves injecting a voltage disturbance into the buck converter with load changes of up to 20%. Results demonstrate the superiority of the AOA-optimized PID controller in voltage recovery. It demonstrates a faster response time and outstanding voltage regulation performance, while also exhibiting minimal performance degradation during load changes. This study concludes that the AOA optimization algorithm surpasses other methods in tuning the PID controller for closed-loop DC-DC buck converters

Induction and maintenance of callus from leaf explants of Mirabilis jalapa

Mirabilis jalapa L., commonly known as ‘four o’clock plant’ produces a strong, sweet smelling fragrance after the flowers open at late afternoon. It is a well known ornamental plant as the flowers of different colours can be found simultaneously on the same plant or an individual flower can be splashed with different colours. The colour-changing phenomenon is one of the unique characteristics of M. jalapa as it can display flowers with different colour when it matures. Apart from its ornamental value, it has also earned its place in herbal medicine practices around the world. Its array of biological activities continues to support its use worldwide for control of viruses, fungi and yeast. In this study, callus culture was initiated from the leaf explants of M. jalapa. The suitable strength of MS (Murashige and Skoog) nutrient media was determined and the effects of different types of auxins [4-amino-3,5,6-trichloro picolinic acid (picloram), 2,4-dichlorophenoxyacetic acid (2,4-D), -naphthaleneacetic acid (NAA)] and cytokinin [6-benzyl amino purine (BAP)] at 0.0 2.5, 5.0, 7.5, 10.0, and 20.0 M were investigated in order to determine the suitable callus induction and maintenance media. The establishment of callus culture was greatly influenced by the strength of MS medium, type as well as the concentration of plant growth regulators (PGRs) used. The best callus induction response was obtained on half strength (½) MS media supplemented with 20.0 M picloram which produced healthy and friable callus. Meanwhile, ½ MS supplemented with NAA or BAP as well as PGR-free medium did not produce any callus; rather, explants became necrotic after 3 to 4 weeks of culture. Calli were successfully maintained in ½ MS supplemented with 10.0 M picloram. Callus in maintenance medium showed a sigmoid growth pattern and reached a maximum growth rate between weeks 1 and 3

UV-LED

UV-LED is part of a small satellite technology demonstration mission that will demonstrate non-contacting charge control of an isolated or floating mass using new solid-state ultra-violet light emitting diodes (UV-LEDs). Integrated to the Saudisat-4 spacecraft and launched onboard the Dnepr in June 19, 2014, the project is a collaboration between the NASA Ames Research Center (ARC), Stanford University, and King Abdulaziz City for Science and Technology (KACST). This technology demonstration will validate a novel method of charge control that will improve the performance of drag-free spacecraft allowing for concurrent science collection during charge management operations as well as reduce the mass, power and volume required while increasing lifetime and reliability of a charge management subsystem. These improvements are crucial to the success of ground breaking missions such as LISA and BBO, and demonstrate the ability of low cost small satellite missions to provide technological advances that far exceed mission cost

Flight Avionics Hardware Roadmap

As part of NASA's Avionics Steering Committee's stated goal to advance the avionics discipline ahead of program and project needs, the committee initiated a multi-Center technology roadmapping activity to create a comprehensive avionics roadmap. The roadmap is intended to strategically guide avionics technology development to effectively meet future NASA missions needs. The scope of the roadmap aligns with the twelve avionics elements defined in the ASC charter, but is subdivided into the following five areas: Foundational Technology (including devices and components), Command and Data Handling, Spaceflight Instrumentation, Communication and Tracking, and Human Interfaces

COTSAT Small Spacecraft Cost Optimization for Government and Commercial Use

Cost Optimized Test of Spacecraft Avionics and Technologies (COTSAT-1) is an ongoing spacecraft research and development project at NASA Ames Research Center (ARC). The prototype spacecraft, also known as CheapSat, is the first of what could potentially be a series of rapidly produced low-cost spacecraft. The COTSAT-1 team is committed to realizing the challenging goal of building a fully functional spacecraft for $500K parts and$2.0M labor. The project's efforts have resulted in significant accomplishments within the scope of a limited budget and schedule. Completion and delivery of the flight hardware to the Engineering Directorate at NASA Ames occurred in February 2009 and a cost effective qualification program is currently under study. The COTSAT-1 spacecraft is now located at NASA Ames Research Center and is awaiting a cost effective launch opportunity. This paper highlights the advancements of the COTSAT-1 spacecraft cost reduction techniques

Screening for Sarawak Paddy Landraces with Resistance to Yellow Rice Stem Borer, Scirpophaga incertulas (Walker) (Lepidoptera: Crambidae)

The yellow rice stem borer, Scirpophaga incertulas (Walker) is a prevalent pestin paddy fields worldwide. In Sarawak, a survey on pest of paddy carried out from 2009 to 2011 covering 166 paddy fields revealed that rice stem borers caused 11.4% of total paddy damage. In order to reduce the damage, identifying resistance paddy variety is crucial. The objective of this study was to screen Sarawak paddy landraces with resistance toS. incertulas. Twelve Sarawak paddy landraces were selected randomly for this study. Antixenosis resistance screening was performed in aquariums (60 x 28 x 33 cm). Three replications of one-month-old seedlings were randomly arranged in aquarium and exposed to adult S. incertulas. The number and position of egg mass on each plant were recorded. Egg mass abnormalities were also observed. For antibiosis, rice culms of two-month old seedlings from each landrace were infested with larvae. The length of surviving larvae from five rice culms was measured. The experiment revealed variations in landrace of preference for ovipositing. Among the twelve Sarawak paddy landraces, Kanowit was more preferred by S. incertulas for ovipositing in comparison to other paddy landraces suggesting susceptibility towards the pest. Abaxial leaf surface was the preferred oviposition site. There was no clear antibiosis response of the paddy landraces towards S. incertulas larvae in this study

Electronic Parts Applications Reporting and Tracking System (EPARTS)

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