Switching Time

Absorption  and  dispersion  properties  of  a  V-shaped  quantum-dot  molecule  are  investigated.  The  effect  of
decay-induced  interference  and  inter-dot  tunneling  on  phase  control  of  the  absorption  and  the  dispersion
is  then  discussed.  We  find  that  in  the  presence  of  decay-induced  interference  or  inter-dot  tunneling  the
group  velocity  of  a  light  pulse  is  completely  phase  dependant.  The  required  switching  times  for  switching
the  group  velocity  of  a  light  pulse  from  subluminal  to  superluminal  pulse  propagation  is  then  discussed.

The paper describes the development of an electrically operated pneumatic fast-switching valve for pneumatic position control systems. The valve was designed and fabricated as an on–off valve with 2/2-way function and its characteristics were investigated. The detailed theoretical analysis and preliminary tests were carried out on the manufactured valve and showed that the switching time of the single stage valve

A four level inverted Y-type quantum well semiconductor is proposed based on phase-sensitive Kerr nonlinearity with a closed-loop configuration. It is found that as the Rabi-frequency of coupling field increases, the maximal Kerr nonlinearity intensifies and at the same time the probe linear and nonlinear absorption decreases at Telecom wavelength λ=1550nm. The impact of an incoherent pumping field as well as the relative phase of the applied fields on nonlinear optical properties of the QW medium is then discussed. The temporal behavior of the Kerr nonlinearity and the required switching time for switching the nonlinear dispersion are also discussed. The results may be useful for understanding the switching feature of EIT-based slow light Kerr nonlinearity enhancement systems and have potential application in optical information processing and transmission.

The Voltage source inverters (VSI) give desirable inverter output voltages and control the drives in most medium and large power applications. The inverter outputs are influenced by Pulse width modulation (PWM) methods. The space vector-PWM (SVPWM) is one of the most effective switching control strategies used to control inverter outputs. In this article, an efficient SVPWM technique is modeled and used in two-level Three-Phase VSI. The SVPWM module mainly consists of an Angle generation unit (AGU) using Phase-locked Loop (PLL), Sector generation unit (SGU), time duration module (TDM), Switching time generation (STG) Module, and lastly, SVPWM gate pulse generation (GPG) module. The SVPWM techniques generate six gate pulses and are used in VSI. The Three-Phase VSI is modeled using SVPWM and generates the Line and phase voltage for the given Load. The simulation results of each SVPWM are analyzed, and VSI generates the line and phases voltage output waveforms. The THD of 29.63% is achieved at Modulation index 0.99 with a 425.5V peak output voltage.

In this paper we characterize the switching dynamics of a novel three section slotted Fabry-Perot laser for phase modulated transmission systems. The static characterization shows that an average linewidth of 538 kHz is achieved for all 25 ITU 100 G channels of the laser, which is able to support differential quadrature phase-shift-keying (DQPSK) transmission at 10 Gbd symbol rate. An average wavelength switching time of 5 ns is also demonstrated using two measurement techniques. The performance during switching is examined by measuring the time resolved bit error rate (BER) of a 10.7 Gbd DQPSK packet transmission system. The time taken to go from no measured errors on one channel to no measured errors on the other channel is found to be less than 16 ns for the switching combination studied.

ZnO nanorod polymer hybrids (i.e., ZnO nanorods coated with a block copolymer with a short anchor block (dopamine) and a longer solubilizing block of polystyrene (PS)) form liquid crystalline (LC) phases if they are dispersed at high concentration e.g., in a PS oligomer matrix. Due to the high mobility of the low T(g) -matrix the nanorod polymer hybrids show a switching behavior under an applied AC electric field. Hence, the orientation of the nanorod mesogens can be changed from planar (parallel to the substrate) to homeotropic (perpendicular) in full analogy to the switching of low molecular liquid crystals in an electric field. Dielectric measurements show that such a switching is mainly due to the cooperative LC behavior, because the rods themselves exhibit only a very small effective dipole moment. The process can be investigated by polarizing microscopy. SEM images show the orientations of the individual nanorods, which correspond to the Fredericks transition well known for li...

Recent advances in the reconfigurability concept have now made it possible to design blocks of the transceiver chain which can change its functionality in real time. Reconfigurability in general can provide performance improvements and reduction of the battery power consumption. In this paper we focus on the well-known Rake principle and we propose a reconfigurable receiver structure, able to support the required processing for a RAKE combination and a one-stage inter-path interference canceller (IC). This approach allows a more efficient use of the constraint calculation power of the reception block and improves the system performance. Through theoretical analysis and simulation, we also investigate a controller which can supervise, at run-time, switching between the two possible configurations.

Donor–acceptor–donor (DAD) type benzimidazole (BIm) and 3,4 ethylenedioxythiophene (EDOT) bearing monomers were synthesized and electrochemically polymerized. Pendant group at 2-C position of the imidazole ring was functionalized with phenyl (P1), EDOT (P2) and ferrocene (P3) in order to observe substituent effect on electrochemical and electrochromic properties of corresponding polymers. Spectroelectrochemical results showed that different pendant groups resulted in polymers with slightly different optical band gaps (1.75, 1.69 and 1.77 eV respectively) and different number of achievable colored states. Optoelectronic performance and comparison of results with other well known π-accepting benzazole bearing DAD type polymers were reported in detail.

Y. Cotronis and J. Dongarra (Eds.): Euro PVM/MPI 2001, LNCS 2131, pp. 327–334, 2001. й Springer-Verlag Berlin Heidelberg 2001 ... PDES: A Case Study Using the Switch Time Warp* ... Remo Suppi, Fernando Cores, and Emilio Luque ... Dept. of Computer Science, ...

The Voltage source inverters (VSI) give desirable inverter output voltages and control the drives in most medium and large power applications. The inverter outputs are influenced by Pulse width modulation (PWM) methods. The space vector-PWM (SVPWM) is one of the most effective switching control strategies used to control inverter outputs. In this article, an efficient SVPWM technique is modeled and used in two-level Three-Phase VSI. The SVPWM module mainly consists of an Angle generation unit (AGU) using Phase-locked Loop (PLL), Sector generation unit (SGU), time duration module (TDM), Switching time generation (STG) Module, and lastly, SVPWM gate pulse generation (GPG) module. The SVPWM techniques generate six gate pulses and are used in VSI. The Three-Phase VSI is modeled using SVPWM and generates the Line and phase voltage for the given Load. The simulation results of each SVPWM are analyzed, and VSI generates the line and phases voltage output waveforms. The THD of 29.63% is achieved at Modulation index 0.99 with a 425.5V peak output voltage.

ABSTRACT This paper describes the design, construction and testing of a 10 kVA three-phase to three-phase Matrix Converter induction motor drive. The converter has been built using discrete 65 Amp MOS controlled thyristors (MCTs). The commutation time has been minimized to avoid any unnecessary waveform distortion, particularly at low frequencies under v/f control. This minimization gives the Matrix Converter superior waveform quality in comparison to a conventional inverter. The converter has been tested using an 11 kW induction motor and full results of these tests are presented.

Linear switched systems are a wide class of hybrid dynamical systems consist of linear subsystems, and switching signals. In this paper, a new method is proposed to obtain the optimal switching time of switched linear systems which have some constraints in their switching signal. Buck and Boost converters are well matched in this model of constrained linear switched systems. The optimal switching signals are achieved based on minimization of an error cost function within each fixed period. The proposed method is employed to control the output voltage of a Buck and a Boost converter. Simulation results show that the proposed method is significantly robust to the input voltage, and output load resistance variations.