The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Condition monitoring and prognosis are effective methodologies to reduce the downtime and maintenance cost and improve the reliability and lifespan for power electronic converter systems. This paper presents a model-based method to implement the condition estimation and a data-driven method to conduct the prognosis for boost converter. Firstly, the equivalent circuit for non-ideal boost converter...
In the field of defense science and technology, some long-life and high-reliability products cost a lot to carry out reliability test, including life test, degradation test and enhancement test. Thus, a more effective product testing and data analysis method are expected. Reliability enhancement test (RET) is commonly employed to improve products reliability, whose data is usually utilized to determine...
Effective fault diagnosis for mission-critical and safety-critical systems has been an essential and mandatory technique to reduce failure rate and to prevent unscheduled shutdown. A novel optimization deep belief network (DBN) in this study has been proposed for a closed-loop single-ended primary-inductance converter (SEPIC) fault diagnosis. Firstly, the wavelet packet decomposition technique is...
Mesoporous SiO2/Zn2SiO4:Eu3+ hollow nanospheres were successfully synthesised via the combination of layer-by-layer and combustion technique. The structures and morphologies of as-obtained SiO2/Zn2SiO4:Eu3+ nanospheres were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N2 adsorption–desorption isotherms techniques. SiO2/Zn...
In order to overcome the shortcomings of traditional wavefront achieving techniques, which cannot capture the wavefront in the case that an obstacle presents in front of the reference source, we propose and demonstrate a new wavefront measuring method by exploiting a plenoptic configuration. By processing the 4-D light-field information captured by plenoptic configuration, the obstacle's information...
The paper presents results of a study of malware spreading in heterogeneous networks using epidemiological modeling framework. The model is one of the first to incorporate heterogeneity among the three components of the network: software, hardware and network type. This model also allows for both cyber and non-cyber-related impact on the mission. The unified approach taken in this study aggregates...
Android system holds a dominant role in the world market of mobile systems and supports rich types of events. However, most events occur unpredictably, which may lead to concurrency bugs and cause serious damages. Although many concurrency bugs have been detected in Android system, they often cannot be replayed and are hard to be fixed due to the framework-based and event-driven nature of Android...
Usable capacity refers to the maximum capacity in theory that a fully charged battery can release, and is often used as an indicator in state of health (SOH) estimation for lithium ion batteries. The traditional method for measuring usable capacity is mainly based on voltage data in the discharge process with a constant current. However, the discharge current of a lithium ion battery in operation...
Field data is often used as the basis for the prediction of an airplanes maintenance request. In the traditional methods, maintenance request predictions are mainly obtained immediately using data. However, uncertainty analysis during the failure detection is ignored, which makes maintenance request inaccurate. To overcome the above problems, a novel approach is proposed in this paper: a multivariate...
Due to the critical applications of single-ended primary inductance converter (SEPIC) in various fields, it is necessary for the SEPIC converters to predict their performance trends. Closed-loop control instead of open-loop control have been adopted in SEPIC converters, and the fault prognostic methods used for open-loop converters sometimes are no longer suitable for closed-loop converters. Besides,...
The implementation of diagnostic methodologies to power devices and converters has become essential and critical in many fields. A lot of previous research demonstrated detection of hard faults, such as open or shorted switching elements in the power systems. However, little progress has been made on soft faults diagnosis. The soft faults related to components degradation degrade the system's performance...
Portable Power System (PPS) supplies energy for electronic devices outdoors. The lithium-ion batteries are adopted as a kind of ideal energy storage unit for the PPS. In order to monitor batteries, parameter identification should be performed on batteries. To achieve the tradeoff between the accuracy and simplicity, the first order RC model is used as the fundamental model for lithium-ion batteries...
Nowadays, Web services are widely used because of their interoperability and reusability. Multiple Web services can be composed following some business logic specified by BPEL (Business Process Execution Language) scripts. Since BPEL scripts allow specifying concurrent workflow, typical concurrency problems, such as data race, atomicity violation and order violation, also commonly occur in BPEL scripts...
Multi-frame super resolution (MFSR) aims to estimate a high resolution image from a set of low resolution images. Such task is ill-posed and typically computationally costly. We propose a new MFSR forward model, and reformulate the MFSR problem into a problem of multi-frame blind deblurring (MFDB) which is easier to be addressed than the former. We further efficiently solve the MFBD problem via attacking...
A high performance microelectromeachical systems(MEMS) capacitive accelerometer in seismic detection system requires a low noise programmable analog signal for gravitational acceleration cancellation. This paper presents a monotone 10-bit digital-to-analog converter (DAC) for this application. The proposed DAC which generates a low noise analog signal is used to cancel out gravitational acceleration...
Impedance as one of the most important parameters of a battery has been studied a lot. While most works only consider the impedance is related with the state-of-charge (SOC), very little attention has been put upon the rate dependence of impedance. In this work, the impedance of a battery has been considered to be dependent on the SOC and the charging or discharging rate. A series of charging and...
This paper presents an improved vision-based algorithm for detecting and recognizing vehicle logos in images captured by road surveillance cameras. Vehicle logo recognition is quite a challenging task considering the low resolution of the logos, the wide range of variability in illumination and the interference of the air-intake grille. However, our system, assessed on a set of 1386 vehicle images...
In this paper, we present a novel tunable phase shifter at 2.4GHz, based on composited right/left-handed (CRLH) transmission line. The phase shifter is designed by adopting LC loaded lines with varactor diodes. The corresponding DC bias circuit is also designed. By changing the bias voltage of the varactor diodes, the phase shift of five cascaded phase shifter units can be changed continuously within...
A compact printed log-periodic dipole antenna (LPDA) with distributed inductive load has been presented in this paper. By adding a stub on the top of each element, the dimension of the LPAD can be reduced by 60%. The antenna has obtained an impedance bandwidth of 10GHz (8GHz-18GHz). According to the simulation results, the designed structure achieves stable radiation patterns throughout the operating...
Prognosis of DC-DC power converters is necessary in embedded and safety critical applications to prevent further damages. However, most of the prognostic methods of power converters are focus on the critical components of the converters. Furthermore, the methods seldom consider the effect of changes in operating conditions (e.g. power supply and load). In order to address these problems, an innovative...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.