Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
11,289
result(s) for
"system configuration"
Sort by:
Cost of Not Maintaining a Product Configuration System
This article investigates the cost implications of using a not sufficientlymaintained product configuration system (PCS). A case study is conducted to investigate the financial loss due to poor data quality in products sold through a not-maintained PCS. We calculated the financial loss by comparing the quotations generated by the not-maintained PCS and the quotations for the same product when the PCS was updated.The results indicate that the company has been selling the products with a miscalculated 20% lower cost than the actual one. Comparing this financial loss to the cost required to keep the PCS up-to-date, we show that the former is significantly higher than the latter. The research concludes that the realized success and benefitsof utilizing a PCS are related to its maintenance and data quality.
Journal Article
Resilient wide-area monitoring and protection scheme with IEEE Std. C37.118.1-2011 criteria for complex smart grid system using phase diagram
Challenges facing power system protection in a wide-area system are latency and full coverage of a wide-area disturbance. The complexity of large-scale power system configurations has led to challenges in the design of coordination and operating systems for protection relays. Local measurements used for primary and backup protection cannot consider wide system disturbances. A new wide-area-monitoring-system-based primary protection is presented for a complex power system involving double and single lines. It is based on describing the non-linear dynamic operation of the transmission lines during a fault in the form of a set of differential equations that are solved through paths movements in a phase diagram. The fault on the lines can be precisely recognised. The speed of the traditional communication media limits wide-area monitoring as backup protection. This study presents the primary protection scheme for double and single circuits in a wide area for the first time based on fourth-generation technology with low latency. The justification for applying the proposed scheme as primary protection in a wide-area-monitoring system is discussed. The number of relays on the studied configuration is reduced from 18 local relays to only 5 phasor measurement units for protecting the lines in the area.
Journal Article
Impact of root cutting on root architecture and water use efficiency of rice seedlings
【Objective】An optimal root architecture not only provides anchorage for plants but also enhances the acquisition of water and nutrients, which are unevenly distributed in the soil profile. This study experimentally investigates how root cutting can improve the root architecture of rice seedlings and its subsequent impact on water use efficiency.【Method】The experiment used the rice variety Lvhan 639 as the model plant and included two treatments. In the first treatment, half of the root system was removed at 5, 7, 9, and 11 days after seedling emergence. In the second treatment, root cutting was conducted 9 days after seedling emergence, with the root being cut at 1.5 cm from the root tip (A1.5), at the middle of the root (A1/2), and cut the root to 2.0 cm (A2.0). The control group did not undergo any root cutting. In each treatment, we measured root architecture, plant height, stem diameter, root-to-shoot ratio, photosynthetic traits, and water use efficiency of the seedlings.【Result】In the first treatment, the most favorable root architecture was observed when half of the root was cut 7 days after seedling emergence. In the second treatment, (A2.0) produced the optimal root architecture. Root cutting reduced the root-to-shoot ratio in all cases, although the differences between the two treatments were not statistically significant. In the first treatment, the lowest root-to-shoot ratio (0.228 5) occurred when the root was cut 9 days after seedling emergence. Root cutting improved water use efficiency, primarily by decreasing stomatal conductance. In the first treatment, cutting the roots 9 days after seedling emergence increased water use efficiency by 14.93% compared to the control. In the second treatment, cutting the roots to 2.0 cm showed the highest water use efficiency, with a 38.99% improvement over the control.【Conclusion】Root cutting can effectively enhance both root architecture and water use efficiency in rice seedlings. Among the methods tested, cutting half of the root 7 days after seedling emergence or trimming the root to 2.0 cm on the 9th day after seedling emergence were most effective for optimizing root development and increasing water use efficiency.
Journal Article
Flow interference mechanism between airframe and propulsion system in blended wing-body configuration study
The hybrid wing-body (HWB) configuration, which incorporates a conventional aft fuselage and tail assembly to the rear of a blended wing-body (BWB), represents one of the promising configurations for future large and medium-sized military and civil transport aircraft. In this study, we investigated the flow interference mechanisms between the airframe and propulsion system for an HWB layout with a wing-mounted aft engine configuration. Based on the “baseline configuration and ventilated nacelle”, we conducted research into the flow interference mechanisms. It is found that the upper surface of the inner wing section in the HWB baseline configuration exhibits favorable high-speed and low-speed flow characteristics, providing a uniform and stable flow environment for engine installation.
Journal Article
Multilayer Collaborative Optimization for the System Configuration, Operation, and Maintenance of Smart Community Microgrids
Smart community microgrids are capable of efficiently addressing the energy and environmental challenges faced by cities. However, the inherent instability of renewable energy sources and the diverse nature of user demands pose challenges to the safe operation of community power systems. In this article, we first introduce a comprehensive system architecture, and an operational framework based on Energy Internet of Things (EIoT), which considers system‐level safety, reliability, and cost‐effectiveness, thereby enhancing the system’s coordination and performance. Next, we propose a bi‐level coordinated optimization method based on the users’ electricity consumption behaviors. At the planning level, we employ a multiobjective optimization approach to determine the most suitable microgrid configurations that cater to the requirements of various user groups, and the results derived from adaptive weight particle swarm optimization (PSO) algorithm are fed back to the operational level. At the operational level, a 24‐h time scale is selected, and the economic efficiency problem is addressed using a linear programming method. The operational decision results are then fed back to the planning level for major maintenance of the microgrid system. Meanwhile, we employ trend prediction methods to categorize maintenance tasks into short‐term and long‐term operations based on an analysis of daily operational data. The short‐term prediction results can serve as a reference to guide daily short‐term operations and maintenance tasks, while the long‐term prediction results can inform renovation and reconstruction initiatives for community microgrid. Finally, we choose a community as the subject of our study, and the results indicate that our research can provide new methods for the design and operation of microgrid in smart communities, thereby improving the scalability of the community’s power system.
Journal Article
Computational modular system configuration with backward compatibility
Abstract Modularization has played a significant role in product design and system configuration for both manufacturers and customers. Modularization enables mass customization, collaborative product design, concurrent engineering, and short product development cycle from the view point of manufacturers, while it enables high reusability, easy system configuration, and quick installation of parts from the viewpoint of customers. One of the key enablers of modularization is standardized interfaces that connect parts. The standardization has facilitated computational product design by enabling the automation of product design processes. As technology evolves, challenges from the variants of standardized interfaces, such as different versions of an interface, have emerged. A version mismatch causes incompatibility. In order to increase compatibility, interfaces are designed to support backward compatibility. This paper proposes an artificial intelligence planning–based mathematical framework for computational system configuration to support backward compatibility. The case study shows the significance of the design with the consideration of backward compatibility by demonstrating the capability of the proposed framework that automatically discovers a better design solution that cannot be identified when backward compatibility is not considered. Finally, experiments are conducted to prove the optimality of the solutions from the mathematical framework and to showcase the advantages of the framework. The proposed mathematical framework is expected to serve as a benchmarking tool, in terms of solution quality and time, for heuristic methods to be developed in the future.
Journal Article
Aerodynamic shape optimization of aft propulsive fuselage concept using an internal/external integration model
The new turboelectric aircraft with aft propulsion fuselage concept (APFC) utilizes an electrically driven fan powered by main engines that ingest the fuselage boundary layer for increased propulsive efficiency. However, with the high integration of the fuselage and the aft propulsion system, the APFC produces the coupling problem of the internal/external flow field. In this paper, an integration model using computational fluid dynamics (CFD)-based aerodynamic shape optimization is performed to study the power savings of the APFC to a reference traditional podded configuration. The results show that the power savings of APFC have a better performance compared to a traditional propulsion system.
Journal Article
Research on hybrid propulsion system with parallel power configuration: theory and experiment based on dynamics
With the increasingly serious problems of international energy shortage and environmental degradation, the adoption of hybrid energy forms represents an effective solution to these challenges and has been widely implemented in the propulsion systems of aircraft, vehicles, and ships. For the hybrid propulsion system with parallel power configuration, a comprehensive investigation has been conducted to understand the system’s dynamic characteristics and the evolution laws associated with power parameters. By appropriately simplifying of the actual propulsion system, a nonlinear dynamic model with multi-factor and multi-degree-of-freedom (multi-DOF) coupling is established. The dynamic equations are solved by numerical method, and the motion state of the system under various rotating speeds is revealed through global and local characteristic analyses. The evolution laws of the dynamic characteristics are studies with respect to different combinations of key power parameters, including (
λ
ω
,
λ
f
) and (
f
o
,
λ
f
), and the impact of these parameters on the system stability is discussed. Finally, an experimental platform with a parallel drive system is established to quantitatively assess the effects of rotating speed and torque ratio on frequency response, dynamic characteristics, and power efficiency. The results indicate that low rotating speed, heavy load, and large torque ratio have positive implications for the stability of the propulsion system. However, an excessively low torque ratio can significantly compromise power efficiency. It is anticipated that this research will serve as a valuable reference for the design of dynamic stability and optimization of the power configuration in hybrid propulsion systems.
Journal Article
A review of electrified propulsion system concepts for advanced aircraft
The active development of electrical technology provided leeway to creating fundamentally new configurations of propulsion systems and novel aerodynamic layouts of aircraft. Currently, this area of science is in the initial stage of development, but thanks to its huge potential, the number of projects with new propulsion system configurations is growing annually at an exponential rate. A classification of new types of propulsion system configurations is presented in order to understand its wide variety. Beneficial and negative impacts of each configuration are presented.
Journal Article