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A noise resilient multi-step ahead deep learning forecasting technique for solar energy centered generation of green hydrogen
No full textGeneration of green hydrogen based on solar energy is significantly dependent upon photovoltaic (PV) panel energy, which is reliant on the stochastic and intermittent global horizontal irradiance (GHI). Further, if inconsistent power output from PV panels due to influence of noise interferes with continuous supply of energy needed for electrolysis process, then reliable generation of green hydrogen may be impacted. Therefore, in this study, preliminary fast fourier transform (FFT) technique for noise removal is utilized and thereafter, singular spectrum analysis (SSA) algorithm is integrated with Gated Recurrent Unit (GRU) in order to enhance the accuracy during forecasting of green hydrogen reliant on GHI at multiple time steps. The suggested methodology is assessed using GHI dataset for Jaipur site (Rajasthan, India) obtained from National Institute of Wind Energy (NIWE) portal. The monthly average prediction for solar energy centered green hydrogen generation by employing the proposed methodology at Jaipur location corresponds between 0.010 kg/m2 (10 × 103 kg/km2) to 0.020 kg/m2 (20 × 103 kg/km2) in diverse circumstances. The suggested forecasting algorithm provides a reliable and precise methodology that will significantly supports low-carbon economy goals.journal articl
Attitude and orbital control simulation for VERTECS
Get PDFThe Visible Extragalactic background RadiaTion Exploration by CubeSat (VERTECS) is designed for observing Extragalactic Background Light(EBL). VERTECS mission requires attitude control stability better than 10 arcsec (1σ) per minute, pointing accuracy better than 0.1 deg, and the slew rate faster than 1 deg per sec. We discuss the software-in-the-loop (SIL) attitude simulator simulation to verify whether the current Attitude Determination Control System (ADCS) design and the planned orbit can meet the requirements for EBL observations. We simulate the attitude control system with the simulation software, taking into account the attitude control commands, the parameters of the ADCS hardware, and the expected attitude disturbances in the assumed orbit. This simulation shows the sequence of attitude maneuvers needed to meet the requirement. The simulation results indicate that the current observation sequence is feasible.journal articl
A self-stabilizing distributed algorithm for the 1-MIS problem under the distance-3 model
Get PDFFault-tolerance and self-organization are critical properties in modern distributed systems. Self-stabilization is a class of fault-tolerant distributed algorithms which has the ability to recover from any kind and any finite number of transient faults and topology changes. In this article, we propose a self-stabilizing distributed algorithm for the 1-MIS problem under the unfair central daemon assuming the distance-3 model. Here, in the distance-3 model, each process can refer to the values of local variables of processes within three hops. Intuitively speaking, the 1-MIS problem is a variant of the maximal independent set (MIS) problem with improved local optimizations. The time complexity (convergence time) of our algorithm is O(n) steps and the space complexity is O(logn) bits, where n is the number of processes. Finally, we extend the notion of 1-MIS to p-MIS for each nonnegative integer p, and compare the set sizes of p-MIS (p = 0, 1, 2...) and the maximum independent set.journal articl
二相ステンレス鋼の溶接金属におよぼすティグ溶接条件の影響
Get PDF二相ステンレス鋼では，溶接部のフェライト量が過多または過少になると耐孔食性が低下するため，そのフェライト量が30～70％または30～60％になる溶接条件を選定する必要がある1)，2)．また，溶接金属のフェライト量は，オーステナイト生成元素であるNおよびNiの影響によって変化しやすい2)．
二相ステンレス鋼のティグ溶接では，シールドガスにArを使用した場合，溶接中に溶融池からNが放出されるため，シールドガスからN2を供給して溶接金属のN含有量を確保することが推奨されている2)，3)．また，二相ステンレス鋼の溶接材料はNi含有量が母材よりも2～4％高くなっているが，突合せ溶接（片面）の初層溶接では希釈が大きくなり，溶接金属のNi含有量が十分に得られない場合がある．そのため，初層溶接金属のフェライト量はNの放出の影響と重畳してより過多になることが想定されるが，実際には過多になりにくい3)．そこで，シールドガスからN2を供給した場合における溶接金属の初層と最終層のフェライト量を確認して，溶接金属のN含有量およびフェライト量におよぼすシールドガスの影響を評価するとともに，初層溶接後と二層目溶接後の初層溶接金属の断面ミクロ組織とフェライト量を確認して，初層溶接金属のフェライト量におよぼす二層目溶接の影響を評価した．さらに，溶接金属のN含有量とフェライト量の関係，ならびにフェライト量の測定方法の比較についても以前の実験結果と合わせて示した．journal articl
Latest technologies and future prospects for neuromorphic AI hardware using non-volatile memory
Get PDF既存ディジタル方式を越える性能が期待されているニューロモルフィックAIハードウェアの構成法として，不揮発性メモリを用いたCiMアーキテクチャについて説明し，最新技術とその課題を示す．さらに不揮発性メモリを応用したアナログ的な演算手法として，著者らが提案している時間領域アナログ集積回路方式における設計法と，高効率化に適したリザバー計算モデルについて紹介する．journal articl
Dynamic Fault Detection and Reconfiguration System for Planetary Exploration Rovers
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Performance Evaluation of Techniques for Enhancing Memory Capacity of Reservoir Computing
Get PDFリザバーコンピューティング（RC）は高い処理性能と簡便な学習法が注目され，物理現象によってその機能が実現される物理リザバー[1]など様々なモデルや実現手法が提案されている．我々は効率的な集積回路実装が実現できるカオスボルツマンマシンリザバー[2]（CBM-RC）の開発を進めているが，他の物理リザバーと同様に，記憶容量が小さいという課題がある．本研究ではリザバーのモデル自体に変更を加えることなく，その構成の工夫のみによってリザバーの記憶容量を改善する手法を提案し，性能評価を行った．conference pape
Accurate ESR Monitoring of a DC-Link Capacitor with Switching Ripple Voltage by a Leafony
Get PDFCondition monitoring helps improve the reliability of power electronic converters including their DC-link capacitors because it can predict converter failure and degradation. In practice, however, condition monitoring usually utilizes sensors to obtain health condition, which are constraint with regard to cost and size. This paper proposes condition monitoring method of DC- link capacitor in a three-phase PWM inverter with a front-end six- pulse diode rectifier by a Leafony that is a tiny microcontroller. The proposed method measures equivalent-series resistance (ESR) of the capacitor, where the Leafony is utilized to sense the switching ripple voltage of the DC-link capacitor and to perform a Fast Fourier Transform (FFT) analysis of the switching ripple voltage of the DC-link capacitor. Experimental results obtained from a 200-V laboratory system have confirmed that measuring the switching ripple voltage improves the accuracy of the ESR.journal articl