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To ensure the reliability and safety, hydraulic/electro-hydrostatic dissimilar dual redundant actuation system is widely used in advanced civil aircraft. Considering the change of dynamic performance of hydraulic actuator (HA) and electro-hydrostatic actuator (EHA), this paper establishes performance reliability model based on parameter drift model, and presents the calculation methods of performance...
To deal with maintenance correlation of parallel structure with same elements in repairable system, a new method that parallel structure is equivalent to one element and then its reliability parameters are calculated is presented. GO method is firstly used in steady-state availability analysis and qualitative analysis for Hydraulic Transmission Oil Supply System (HTOSS) of Power-shift Steering Transmission...
Land surface albedo is critical in earth radiation budget and global climate monitoring. At present, models and algorithms for land-surface albedo retrieval from diverse satellites have been well developed. However, limited sampling angles from mono-sensor and coarse temporal resolution restrict the further promotion and application of albedo. Multi-sensor observations offer more information of land...
The paper details the equations used to simulate a dielectric barrier discharge (DBD) and presents a summary of the results obtained. A model for dielectric barrier discharge was divided into two phases, i.e., propagation in air and along the surface of a solid insulator. The microscopic essence of a streamer discharge was revealed and investigated using a detailed self-consistent plasmochemical model...
Besides the hardware/software failure of switched Ethernet, the capability of data transmission affects its performance and reliability. After summarizing the influence factors of Ethernet service capability, this paper focuses on the time delay oriented reliability model and analysis method. Based on the operational mechanism analysis of Avionics Full Duplex Switched Ethernet (AFDX), this paper emphasizes...
Aging is the main failure mechanism of rubber seal ring during the storage period for hydraulic actuator. Considering the influence of temperature, oxygen concentration and mechanical force, this paper presents an integrated aging model based on the volume variation, elasticity modulus and molecular reconfiguration. With the slot flow theory, we get the relationship between the material structure...
A fully integrated direct up-conversion transmitter for Chinese electronic toll collection system (ETCS) is presented in a 0.18um CMOS process. Improved isolation between power amplifier (PA) and voltage-control oscillator (VCO) is achieved by configuring the VCO frequency to be 2/3 transmission frequency. A 5.8GHz mixer with an automatic amplitude control (AAC) loop is proposed to obtain better amplitude...
This paper proposes a novel modeling and simulation environment for ship design based on the principles of Model Integrated Computing (MIC). The proposed approach facilitates the design and analysis of shipboard power systems and similar systems that integrate components from different fields of expertise. The conventional simulation platforms such as Matlab®, Simulink®, PSCAD® and VTB® require the...
In this paper, a machine learning based decision support system for a naval shipboard power management system is proposed considering contingencies and load priority. A probabilistic model based Bayes' classifier is implemented to classify the current operation state of the ShipBoard Power System (SPS), depending upon the power system readiness for critical contingencies. Real power, reactive power,...
The problem of teaching introductory programming is a recurrent one which has interested and challenged computer scientists over the years. It has evoked differing philosophies, has motivated new languages and fuelled 'wars' between supporters of different languages and approaches. Much of the discourse surrounding these practices dates from a period when learning was bounded by practical activities...
Robustness of the power system can be enhanced with appropriate autonomic control action following the disturbances. Predictive optimal tuning of real time control parameters from the finite set of control actions is considered in this paper to prevent from impending system deterioration. We present the formulation of generic, higher layer model based Limited Lookahead Control (LLC) approach that...
Different from the previous mechanical and electrical products, aerospace hydraulic actuation system operates in very short mission time with high reliability requirement. How to design a suitable reliability growth testing for the hydraulic actuation system is urgent to the engineering. This paper designs the reliability growth testing scheme based on Weibull distribution and censored time. Comparing...
A special detection device, or an E-Pod is generally installed in a plane to perform the target detection and track mission. Aimed at designing a reliable E-Pod, This paper adopts the SolidWorks to build a physical model of E-Pod, and analyze its strength, stiffness and frequency to assess the feasibility for further improvement. Then this paper offers a way of optimization to ensure the reliability...
This paper focuses on the fault-tolerant operation mechanism and failure mechanism of Avionics Full Duplex Switched Ethernet (AFDX). With the strong correlation among airborne systems, fault tolerance mechanism of full duplex communication and dynamic adjustment strategy, this paper presents an integrated reliability theory and evaluation methodology based on service performance and fault tolerant...
Wireless Sensor Network (WSN) has attracted many concerns in different domains because of its special features. A WSN is a set of a large number of resource constrained sensor nodes which have abilities for information detection, data processing, and short-range radio communication. WSN can be used for both military applications and civil applications with the tasks such as detection and monitoring...
In this paper some key technologies of an optical cavity for a compact Terahertz(THz) Source Based on Free Electron Lasers(FEL) were studied. Firstly, the theory of THz radiation was analyzed by some calculations. The high quality electronic bunch beams with energy 5.6-9.9MeV can produce THz radiation with frequency 1-10THz. Secondly, the configuration of the optical cavity was calculated and studied,...
This paper presents the fabrication of the Si/GaInP heterojunction photodetectors using transfer printing of silicon nanomembranes (SiNMs). Doped SiNM was transferred to a GaInP/GaAs substrate using a polydimethylsiloxane (PDMS) stamp. An adhesion interfacial layer was used to bond the two materials together. The heterogeneous integration of Si, GaInP, and GaAs layers formed a P-I-N structure for...
Aiming at bottlenecks (such as ambiguous physical meaning, complex mathematical expression, and so on) in traditional network traffic modeling analysis, this paper puts forward a novel threshold-optimization-based traffic model.In this model, the actual network traffic is divided into two different parts (i.e., a-traffic with burst characteristic, and b-traffic with steady characteristic) according...
Modern industrial processes are often accompanied with high temperature, high pressure, flammable and explosive environment, which makes the safety and reliability very important. Based on the dimension decrease and de-noise of the data by principal component analysis, a support vector data description approach is applied to process monitoring, which is independent of the normal distribution of the...
Statistics of lightning parameters is the key to lightning protection of transmission line. Line corridor grid method (LCGM) is a relatively precise method to calculate lightning parameters along the transmission line, however, this method must base on the original lightning location data, which seriously confines the application of this method on lightning shielding performance estimation of transmission...
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