This paper presents an algorithm for rotating a subimage in place without using any extra working array. Due to this constraint, we have to overwrite pixel values by interpolated values. Key ideas are local reliability test which determines whether interpolation at a pixel is carried out correctly without using interpolated values, and lazy interpolation which stores interpolated values in a region which is never used for output images and then fills in interpolated values after safety is guaranteed. It is shown that linear interpolation is always safely implemented. An extension to cubic interpolation is also discussed.

RF Variable Gain Amplifiers (RF-VGA) are important components for integrated TV broadcast receivers. Analog and digital controlled RF-VGAs are compared in terms of linearity and an AGC loop architecture suitable for digitally controlled RF-VGA is proposed. Further linearity enhancement applicable for CMOS implementation is also discussed.

This paper proposes a scheme for hard handover (HO) between base stations (BSs) that combines bicast with forwarding; it realizes packet-lossless HO as well as low HO control delay. The proposed scheme observes the status of the current channel condition and initiates bicasting, the simultaneous transfer of IP packets from the access router to both the old BS and the new BS, when the probability of HO becomes high; this reduces the control delay imposed by hard HO. When HO becomes unavoidable, only those IP packets remaining in the old BS buffer that are not shared with the new BS are forwarded to the MS; this prevents the loss of IP packets. Computer simulations show that the proposed scheme reduces the HO control delay at 95% cumulative distribution function (CDF) by approximately 1700 (300) msec, 340 (320) msec, and 170 (330) msec compared to the conventional forwarding scheme (the conventional bicast scheme) when the number of users is 80 and the maximum Doppler frequency (fdmax) is 5.55 Hz and data rate (D) on the wired propagation channel is 10, 50, and 100 Mbps, respectively. The results confirm the superiority of the proposed scheme as an IP packet loss prevention scheme for hard HO.

A current-mode squarer/divider circuit with a novel translinear cell is presented for automotive applications. The proposed circuit technique increases the accuracy of the squarer/divider function with better input dynamic range and temperature insensitivity. Simulation results show that the variation of the output current is within ±0.2% over the temperature range from -40 to 140.

A scheme for a low-voltage CMOS syllabic-companding log domain filter with wide dynamic range is proposed and its prototype is presented. A nodal voltage which is fixed in a conventional filter based on the dynamically adjustable biasing (DAB) technique is adapted for change of input envelope to achieve wide dynamic range. Externally linear and time invariant (ELTI) relation between an input and an output is guaranteed by a state variable correction (SVC) circuit which is also proposed for low-voltage operation. To demonstrate the proposed scheme, a fifth-order Chebychev low-pass filter with 100-kHz cutoff frequency is designed and fabricated in a standard 0.35-µm CMOS process. The filter has a 78-dB dynamic range and consumes 200-µW power from a 0.8-V power supply.

In this paper, we propose a novel bicubic method for digital image interpolation. Since the conventional bicubic method does not consider image local features, the interpolated images obtained by the conventional bicubic method often have a blurring problem. In this paper, the proposed bicubic method adopts both the local asymmetry features and the local gradient features of an image in the interpolation processing. Experimental results show that the proposed method can obtain high accuracy interpolated images.

Grey model (abbreviated as GM), which is based on Deng's grey theory, has been established as a prediction model. At present, it has been widely applied in many research fields to solve efficiently the predicted problems of uncertainty systems. However, this model has irrational problems concerning the calculation of derivative and background value z since the predicted accuracy of GM is unsatisfying when original data shows great randomness. In particular, the predicted accuracy falls in case of higher-order derivative or multivariate greatly. In this paper, the new calculation methods of derivative and background value z are first proposed to enhance the predicted power according to cubic spline function. The newly generated model is defined as 3spGM. To further improve predicted accuracy, Taylor approximation method is then applied to 3spGM model. We call the improved version as T-3spGM. Finally, the effectiveness of the proposed model is validated with three real cases.

This paper presents a method for lossy compression of digital video data by parametric line and Natural cubic spline approximation. The method estimates the variation of pixel values in the temporal dimension by taking group of pixels together as keyblocks and interpolating them in Euclidean space. Break and fit criterion is used to minimize the number of keyblocks required for encoding and decoding of approximated data. Each group of pixels at fixed spatial location is encoded/decoded independently. The proposed method can easily be incorporated in the existing video data compression techniques based on Discrete Cosine Transform or Wavelet Transform.

This paper describes a current-steering Digital-to-Analog Converter (IDAC) architecture with a novel switching scheme, designed for GPON Burst Mode Laser Drivers (BMLD) and realized in a 0.35 µm SiGe BiCMOS technology with 3.3 V power supply. The (4+6) segmented architecture of the proposed 10-bit IDAC is optimized for minimum DNL (Differential Nonlinearity). It combines a 4-bit MSBs (Most Significant Bits) unit-element sub-DAC and a 6-bit LSBs (Least Significant Bits) binary-weighted sub-DAC. A switching scheme based on this dedicated architecture yields a high monotony and a fast settling time. The linearity errors caused by systematic influences and random variations are reduced by the 2-D double centroid symmetrical architecture. Experimental results show that the DNL is below 0.5 LSB and that the settling time after the output current mirror is below 12 ns. Although the proposed IDAC architecture was designed for a BMLD chip, the design concept is generic and can be applied for developing other monotonic high-speed current-mode DACs.

This letter presents a novel implementation for Bus-Invert Coding called No Invert-Line Bus-Invert Coding (NIL-BIC) architecture. It not only removes the invert-lines used in previous BIC implementations, but sends the coding information without additional bus-transitions. NIL-BIC can save about 50% more bus-power than the implementations using invert-line.

An effective way to boost power gain without noise figure degradation in a cascode low noise amplifier (LNA) is demonstrated at 4 GHz using 0.35 µm SiGe HBT technology. This approach maintains the same current consumption because a low-pass π-type LC matching network is inserted in the inter-stage of a conventional cascode LNA. 5 dB gain enhancement with no noise figure degradation at 4 GHz is observed in the SiGe HBT LNA with inter-stage matching.

A 10-GHz sub-harmonic Gilbert mixer is demonstrated in this paper using the 0.35 µm SiGe BiCMOS technology. The time-delay when the sub-harmonic LO (Local Oscillator) stage generates sub-harmonic LO signals is compensated by using fully symmetrical multiplier pairs. High RF-to-IF isolation and sub-harmonic LO Gilbert cell with excellent frequency response can be achieved by the elimination of the time-delay. The SiGe BiCMOS sub-harmonic micromixer exhibits 17 dB conversion gain, -74 dB 2LO-to-RF isolation, IP1 dB of -20 dBm, and IIP3 of -10 dBm. The measured double sideband noise figure is 16 dB from 100-kHz to 100-MHz because the SiGe bipolar device has very low 1/f noise corner.

A 5.2 GHz 1 dB conversion gain, IP1 dB = -19 dBm and IIP3= -9 dBm double quadrature Gilbert downconversion mixer with polyphase filters is demonstrated by using 0.35 µm SiGe HBT technology. The image rejection ratio is better than 47 dB when LO=5.17 GHz and IF is in the range of 15 MHz to 45 MHz. The Gilbert downconverter has four-stage RC-CR IF polyphase filters for the image rejection. Polyphase filters are also used to generate LO and RF quadrature signals around 5 GHz in the double quadrature downconverter.

Phase pure cubic (c-) GaN/AlGaN heterostructures on 3C-SiC free standing (001) substrates have successfully been developed. Almost complete (100%) phase pure c-GaN films are achieved with 2-nm surface roughness on 3C-SiC substrate and stoichiometric growth conditions. The polarization effect in c-GaN/AlGaN has been evaluated, based on measuring the transition energy of GaN/AlGaN quantum wells (QWs). It is demonstrated that the polarization electric fields are negligible small in c-GaN/AlGaN/3C-SiC compared with those of hexagonal (h-)GaN/AlGaN, 710 kV/cm for Al content x of 0.15, and 1.4 MV/cm for x of 0.25. A sheet carrier concentration of c-GaN/AlGaN heterojunction interface is estimated to 1.61012 cm-2, one order of magnitude smaller than that of h-GaN/AlGaN. The band diagrams of c-GaN/AlGaN HEMTs have been simulated to demonstrate the normally-off mode operation. The blocking voltage capability of GaN films was demonstrated with C-V measurement of Schottky diode test vehicle, and extrapolated higher than 600 V in c-GaN films at a doping level below 51015 cm-3, to show the possibility for high power electronics applications.

This paper presents a new built-in current sensor (BICS) that detects defects using the current testing technique in CMOS integrated circuits. The proposed circuit is a negligible impact on the performance of the circuit under test (CUT). In addition, no extra power dissipation and high-speed fault detection are achieved. It can be applicable in deep sub-micron process. The area overhead of the BICS versus the entire chip is about 9.2%. The chip was fabricated with Hynix 0.35 µm standard CMOS technology.

Four 50% duty-cycle divide-by-3 prescalers--positively/ negatively triggered sample-sample-hold (SSH) and sample-hold-hold (SHH) prescalers--are designed based on the current switchable D flip-flops and discussed in this paper. The positively triggered SSH and SHH prescalers are fabricated using the 0.35-µm SiGe BiCMOS technology and measured by the real-time oscilloscope and the spectrum analyzer. The SHH prescaler is our proposed structure and demonstrated in this paper. According to the measurement results, under the condition of the same input power, its maximum operation frequency is twice as high as that of the SSH prescaler thanks to better signal synchronization. At 2.7 V supply, the SSH prescaler operates from 500 MHz to 2 GHz as the SHH prescaler performs from 1 GHz to 3.4 GHz. The input sensitivity level of both structures is about -5 dBm, while the maximum output power is also about -5 dBm. The core current consumption is 4.538 mA and 4.258 mA for the SSH and SHH prescalers, respectively.

In this paper, routing properties of cube-based optoelectronic OTIS networks are explored. We show emulations of various cubical network topologies on their OTIS augmented variants, including the n-D grid networks, shuffle-exchange, and de Brujin networks. An analytical performance model for OTIS-cube networks is proposed. The model is validated by means of comparison with rigorously obtained simulation results. Using this model, the performance characteristics of the OTIS-hypercube network are evaluated in view of a number of different constraints. Moreover, we compare the performance characteristics of the OTIS-hypercube with that of equivalent fully-electronic networks under various implementation constraints.

This paper presents a computational approach to the imaging of a partially immersed conducting cylinder. Both cubic-spline method and trigonometric series for shape description are used and compared. Based on the boundary condition and the recorded scattered field, a set of nonlinear integral equations is derived and the imaging problem is reformulated into an optimization problem. The genetic algorithm is employed to find out the global extreme solution of the object function. It is found that the shape described by Fourier series can be reconstructed by cubic-spline. In the opposite case, the shape described by cubic-spline and reconstructed by Fourier series expansion will fail. Even when the initial guess is far away from the exact one, the cubic-spline expansion and genetic algorithm can avoid the local extreme and converge to a global extreme solution. Numerical results are given to show that the shape description by using cubic-spline method is much better than that by the Fourier series. In addition, the effect of Gaussian noise on the reconstruction is investigated.

This paper studies the electromagnetic field radiated by a return stroke, considering even the case of a direct lightning on an aircraft, in the Fraunhofer region. The work here presented is an analysis of a complete discharge case, considering the electric field due to some charged clouds, the presence of a conductive airplane immersed in this external electric field, the channels related to the lightning paths, and the interactions of the field due to the lightning return stroke with a far field located victim system. It could be divided in several steps. Firstly, the cloud-generated electric field has been calculated, and a particular model of the clouds has been introduced. For what concerns the geometrical considerations, a Koch's snowflake shaped cloud has been chosen, in order to achieve a complex geometrical model. To better fit this model with the reality a non-symmetric cloud has been created. Then, a simple aircraft model, according to those reported in literature, has been introduced. The conductive structure of the aircraft interacts with the atmospheric electric field and modifies its distribution. Furthermore, applying a boundary panel method, frequently used in subsonic incompressible aerodynamics, Laplace's equation for the electrostatic potential in the considered domain has been computed, taking into account the presence of the metallic structure. Finally, the inception points on the outer surface of the aircraft are calculated and highlighted. Beginning from those points, in which the probability of discharge is higher, a suitable lightning channel has been created, and the shape of the jagged field signal has been correlated to the tortuous path discharge, even considering the presence of branches. The total electric field given by the first discharge from the cloud to the airplane, by the second discharge from the aircraft to the ground and by the current flowing along the fuselage has been computed and calculated in a far field located observation point.

Simultaneous recordings of eight channel surface myoelectric signals (EMGs) of the biceps brachii muscles of seven subjects were measured in isovelocity elbow flexion against constant load torque. The velocity was 10, 15, 20 and 25 degree/s and the load torque was 5-15 % of the torque obtained at the maximum voluntary contraction (MVC). Individual motor units were identified from the eight-channel surface EMG, by tracking the waveform change which originated from the change of relative position of muscle fiber and electrode. In the low-load (5 and 7% MVC) experiment, 36 examples of recruitment and 22 examples of derecruitment were measured. In the middle-load (10 and 15% MVC) experiment, most of the motor units did not show an obvious change in the firing rate with the elbow joint angle. Average of the firing rates of all the motor units measured at the elbow angle of 0 to 120 degree (13.3-14.7 Hz) did not depend on flexion velocity between 10 to 25 degree/s. It was concluded that the firing rates of the activated MUs were almost constant and that some MUs were recruited and derecruited during the isovelocity flexion movements. These are the first findings.