This paper presents the latest progress in kinetic energy harvesting for wide applications ranging from implanted devices and wearable electronic to mobile electronics self-powered wireless network nodes. The advances harvesters adopting piezoelectric electromagnetic transduction mechanisms are presented. Piezoelectric generators convert mechanical strain on active material electric charge while make use of relative motion between a conductor magnetic flux induce conductor. existent...

User interface (UI) interactions are essential to Android applications, as many Activities require UI be triggered. This kind of could also help malicious apps hide their sensitive behaviors (e.g., sending SMS or getting the user's device ID) from being detected by dynamic analysis tools such TaintDroid, because simply running app, but without proper interactions, will not lead exposure behaviors. In this paper we focus on challenging task triggering a certain behavior through automated...

In this paper, a T-equivalent circuit for loosely coupled transformer, which does not involve magnetic coupling, is presented. A detailed dynamic analysis based on extended describing function technique presented series-series compensated inductive power transfer system. The continuous-time large-signal model, the steady-state operating point, and small-signal model are derived in an analytical closed-form. This includes both frequency phase-shift control. Simulation experimental...

The high-brightness white-light-emitting diode (LED) has attracted a lot of attention for its high efficacy, simple to drive, environmentally friendly, long lifespan, and compact size. power supply LED also requires life, while maintaining efficiency, factor, low cost. However, typical design employs an electrolytic capacitor as the storage capacitor, which is not only bulky, but with short thus hampering performance improvement entire lighting system. In this paper, novel factor correction...

In this paper, a contactless charging system for an electric vehicle (EV) battery is proposed. The consists of three parts: 1) high-frequency power supply from full-bridge inverter with frequency modulation; 2) loosely coupled transformer that utilizes series resonant capacitors both the primary and secondary windings; 3) rectification output circuit uses diode rectifier. With carefully selected compensation network parameters, zero-voltage switching can be ensured all switches within full...

This paper first presents a hybrid-switching step-down dc-dc converter, and then, by introducing transformer isolation, novel phase-shift full-bridge converter is derived for electric vehicle battery chargers. The proposed provides wide zero-voltage-switching range in the leading-leg switches, achieves zero-current-switching lagging-leg uses method to avoid freewheeling circulating losses primary side. Because resonant capacitor voltage of circuit applied between bridge rectifier output...

A novel soft-switching hybrid converter combining the phase-shift full-bridge (FB) and half-bridge (HB) LLC resonant converters' configuration with shared zero-voltage switching (ZVS) lagging leg is proposed to ensure switches in operating at fully ZVS condition. The dual outputs of FB-HB are connected series whole dc-output voltage can be regulated by PWM control within desired range. circuit used secondary side FB reset primary current during freewheeling period, as well transfer more...

An inductive power transfer (IPT) system usually consists of four parts: an ac-dc factor correction (PFC) converter, a high-frequency dc-ac inverter, compensation network comprising loosely coupled transformer (LCT) and the resonant capacitors, rectification output circuit. Due to relatively large air gap, magnetic coupling coefficient IPT is significantly lower than that with tightly transformer. As result, efficiency always main concern for applications possible gap variation or...

An improved twin-bus converter using n + 1 active switches is proposed for the n-string LEDs to be dimmable from true zero rated current level. The n-switches that perform current-loop regulation can operate at very high frequency because of significantly reduced voltage stresses, while achieving efficiency over a wide load range. dimming switch, however, low ensure high-efficiency operation without light flicker. detailed power stage operating principle and control scheme individual string...

In order to design a high-efficiency, cost-effective, high-power driver for supplying multiple light-emitting diode (LED) strings in parallel, novel single-stage bridgeless, soft-switched integrated AC-DC converter is proposed. The proposed can be derived by integrating the totem-pole bridgeless boost power factor correction (PFC) circuit and half-bridge LLC resonant converter. Therefore, number of semiconductors line-current path significantly minimized, losses secondary rectifier diodes...

Traditional villages are the spatial carriers of excellent traditional culture Chinese nation, concentrated expression thousands years farming civilization, and a nonrenewable precious cultural heritage. However, in recent decades, with rapid development urbanization modernization, have rapidly declined or even disappeared. Therefore, exploring distribution characteristics influencing factors clarifying their formation laws, can provide new perspective for continuity protection on...

A field study of student thermal comfort was conducted in the Chinese subtropics. Thermal affects people's physical and psychological health. The performed Hunan University China from March 24 to April 23 2005. Two teaching buildings were selected as sites. measured naturally ventilated classrooms with ceiling fans. total 25 surveyed each classroom visited two or three times 1273 students responded questionnaire. variables at same time: answered a survey on their perception/sensation indoor...

In order to overcome the drawbacks of conventional bridgeless single-ended primary inductance converter (SEPIC) power factor correction (PFC) circuits, an improved SEPIC PFC circuit is introduced by adding additional output diode and inductor. The undesired capacitive coupling loop circulating loss are removed. Thus, high efficiency can be achieved. operation principle design consideration proposed in detail. Furthermore, a novel control method employed current continuous mode without...

Hysteresis current control is an attractive nonlinear current-control method for voltage source inverters when a fast system response required. A well-known disadvantage of hysteresis that the has to operate over wide switching frequency range. This causes increase in losses and increases difficulty designing output filter. The recently proposed parabolic solves this problem by employing pair carriers as band. Through use control, constant can be achieved. In implementation dead time...

To match the key features of light-emitting diode (LED) lighting source and further save power, LED driver also requires long life, while maintaining high efficiency, power factor, pulse-width modulation dimming low cost. However, a typical has following drawbacks: (i) utilise bulky electrolytic capacitor as storage with short lifetime; (ii) employ low-frequency bridge rectifier cell; (iii) engage multiple stages cascade structure for strings. overcome aforementioned shortages, this study...

Parabolic current control is an attractive method with fast transient response and constant switching frequency. Due to the good dynamics of parabolic control, it can be employed in voltage source inverters improve system performance such as minimizing distortion waveforms or waveforms. To implement a sensor required, associated conditioning circuit carrier generators. Since based on real-time information inductor current, any phase delay propagation itself circuitry, limited resolution...