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.
With the wide application of power converters, the electromagnetic interference (EMI) problem of power converters has drawn more and more attention. EMI is caused by high dv/dt and di/dt during the rapid turn-on and turn-off of switching devices, which is harmful to power grids as well as power converters themselves. In order to suppress high EMI peaks which discretely distribute in switching frequency...
With the emergence of renewable energy power generation, varied kinds of DC-AC inverters based on SPWM control including photovoltaic (PV) inverters have been widely applied in practice. However, high-frequency operations of switches under traditional SPWM (TSPWM) will lead to obvious EMI peaks on switching frequency and its multiples, which may cause serious electromagnetic interference (EMI) problem.
A bearingless motor (BM) is an electrical machine with a built-in magnetic bearing element. The stator of the machine is fitted with two sets of windings with different pole-pair numbers, and the pole-pair numbers must be consecutive. The principle of BMs can be applied to most of the conventional motor types, i.e., reluctance motors, induction motors, and permanent magnet synchronous motors (PMSMs),...
Die attach process play an important role for flip chip packaging. The main factors of die attach yield are: process parameter and flux activity. Die attach flux's main function is to promote good wetting during reflow by removing oxidant and pollutants on pad during flux activation stage. Flip Chip package reliability depends on good bump wetting. Therefore, flux has a significant impact on the reliability...
This talk reviews modified uni-traveling carrier (MUTC) photodiodes that have achieved high RF output power levels of up to 1.8 Watt. Discrete wideband photodiodes, narrowband photodiodes, and photodiode arrays and their applications in analog links and photonic microwave generation are discussed.
Heat Assisted Magnetic Recording (HAMR) has been considered to be the most promising candidate for next generation magnetic recording technology beyond 1.5 Tb/in2 and it may extend the recording density to about 5 Tb/in2. However, it may face challenges to further increase the areal density to 10 Tb/in2 and beyond due to the difficulties to further reduce the thermal spot size of < 50 nm because...
Due to increased emphasis on heat assisted magnetic recording, the characterization of switching field distribution (SFD) at elevated media temperatures has become important. In this paper, we introduce an efficient method to measure SFD based on optical heating and MOKE measurement. The Major and minor hysteresis loops of perpendicular magnetic recording media and FePt granular media were acquired...
The continuous interest of both the academic community and the industrial world in wearable devices is driving an ever more extensive research activity on Body Area Networks (BANs). According to the definition provided by the IEEE 802.15 Working Group, they can be defined as a communication system “optimized for low power devices and operation on, in or around the human body (but not limited to humans)...
A remote comparison campaign of Caesium fountain clocks from four National Metrology Institutes in Europe and Asia was carried out in May 2013. Six fountains at Physikalisch-Technische Bundesanstalt (PTB) Germany, Scientific Research Institute of Physical-Technical and Radio Technical Measurements (VNIIFTRI-SU) Russia, National Physical Laboratory of India (NPLI) India and National Institute of Metrology...
The ion beam for vacuum arc ion source in sealed tube neutron generator owns some special features, such as multi-particle mixtures, high-intensity beams, short pulse-width, single gap acceleration system and eccentric beams. It is related to the design of the vacuum arc ion source and beam optics, which affect the insulation withstand of the device, the life of tritium target, the neutron yield,...
A 1 Gbps 105.4 GHz wireless link is demonstrated by directly modulating a photonic integrated dual-laser source. A 50 m link is predicted to be able to achieve error free operation using FEC following optimisation.
Cluster has been used by the government and multiple industries to facilitate business growth for decades, but information telecommunication technology and global integration of the supply chain have challenged competition. The business ecosystem links the stakeholders and their subsidiaries around the world beyond geographic location of industrial clusters. The best practice of smart phone companies...
A technique enabling 10 Gbps data to be directly modulated onto a monolithic sub-THz dual laser transmitter is proposed. As a result of the laser chirp, the logical zeros of the resultant sub-THz signal have a different peak frequency from that of the logical ones. The signal extinction ratio is therefore enhanced by suppressing the logical zeros with a filter stage at the receiver. With the aid of...
We have proposed and experimentally demonstrated a scheme for highly efficient excitation of surface plasmon using a structure consisting of an aperture in metal with a thin dielectric film at one side of the aperture.
A three-electrode system has been fabricated and integrated on the cylindrical polymer capillary surface by micromachining, which could be used as an interventional flexible microneedle for glucose sensor application in future. A UV-lithography system is improved to realize for the first time the multi-layer alignment exposure for cylindrical polymer capillary substrates based on our previous home-made...
In leaves of A. thaliana, there exists an intricate network of epidermal surface layer cells responsible for anatomical stability and vigor of flexibility to the entire leaf. Rho GTPases direct this organization of cell polarity, but full understanding of the underlying mechanisms demands further inquiry. We conduct two experiments: (1) a novel procedure is proposed that could be used in other life...
This paper presents a current output hard-switched full-bridge (HSFB) converter with an intermediate high frequency transformer as an option of a wind energy conversion system (WECS). The wind turbine simulator, based on an induction machine driving a three-phase permanent magnet synchronous generator, is built to simulate the real wind turbine characteristics. Comparative analysis of electrical stresses...
This paper examines the responsibilities and the required skills for Information Technology (IT) security professionals. Content analysis of relevant jobs postings helped identify four types of positions and the associated responsibilities and requisite skills. The identified skills were further analyzed to assess their consistency with the identified responsibilities. Finally, the Body of Knowledge...
The paper presents an effective and efficient method for sensor fault detection and identification within a large group of sensors based upon hierarchical cluster analysis. Fingerprints of the hierarchical clustering dendrograms are found for normal operation using normalized data, and sensor faults are detected through cluster changes occurring in the dendrogram. The proposed strategy is built into...
The paper presents an efficient approach for applied sensor fault detection based on an integration of principal component analysis (PCA) and artificial neural networks (ANNs). Specifically, PCA-based y-indices are introduced to measure the differences between groups of sensor readings in a time rolling window, and the relative merits of three types of ANNs are compared for operation classification...
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.