3D FDTD Implementation for Scattering of Electric Anisotropic Dispersive Medium Using Recursive Convolution Method

The finite-difference time-domain method based on recursive convoltion method (RC-FDTD) for the electric anisotropic dispersive medium is discussed in detail. To exemplify the availability of the three-dimensional RC-FDTD algorithm, the backscattering Radar-Cross-Section(RCS) of a non-magnetized plasma sphere is computed, and the numerical results are the same as the one of the Shift Operater-FDTD method, and show that the RC-FDTD method is correct and efficient. In addition, the co-polarized and cross-polarized backscattering time-domain of a magnetized plasma sphere are obtained by the RC-FDTD algorithm. The results show that when the external magnetic field is implemented, the cross-polarized component appear, evidently.     

Noncooperative Differential Game Based Efficiency-aware Traffic Assignment for Multipath Routing in CRAHN

Comparing to the traditional multihop ad hoc networks, dynamic spectrum environment is the special characteristic of CRAHN (cognitive radio ad hoc networks). Therefore, the cognitive users will show their selfishness on spectrum bandwidth cost in multihop communication. In CRAHN, multipath routing is a reasonable choice when considering efficiency and stability. In order to take further advantage of efficiency of multipath routing, this paper study the efficiency-awareness traffic assignment problem of multipath routing in CRAHN. There are several existing game based traffic assignment schemes for selfish wireless network, however, all of them can not be directly applicable to CRAHN. In addition, none of the existing works studied whether the scheme is efficient. In this paper, a noncooperative differential game is proposed, and the equilibrium of the game is computed and proved to be an efficient traffic assignment for multipath routing in CRAHN. Besides this, we also optimize the total cost of game from the game designer’s point of view, and give a simple example to illustrate the optimization procedure.     

Scalable Gaussian Normal Basis Multipliers over GF(2<Superscript><Emphasis Type=Italic>m</Emphasis></Superscript>) Using Hankel Matrix-Vector Representation

This work presents a novel scalable multiplication algorithm for a type-t Gaussian normal basis (GNB) of GF(2^m). Utilizing the basic characteristics of MSD-first and LSD-first schemes with d-bit digit size, the GNB multiplication can be decomposed into n(n + 1) Hankel matrix-vector multiplications. where n = (mt + 1)/d. The proposed scalable architectures for computing GNB multiplication comprise of one d × d Hankel multiplier, four registers and one final reduction polynomial circuit. Using the relationship of the basis conversion from the GNB to the normal basis, we also present the modified scalable multiplier which requires only nk Hankel multiplications, where k = mt/2d if m is even or k = (mt − t + 2)/2d if m is odd. The developed scalable multipliers have the feature of scalability. It is shown that, as the selected digit size d ≥ 8, the proposed scalable architectures have significantly lower time-area complexity than existing digit-serial multipliers. Moreover, the proposed architectures have the features of regularity, modularity, and local interconnection ability. Accordingly, they are well suited for VLSI implementation.     

Creep behavior of the ternary 95.5Sn-3.9Ag-0.6Cu solder—Part I: As-cast condition

The compression creep behavior was studied for the ternary solder alloy 95.5Sn-3.9Ag-0.6Cu in the as-cast condition. Samples were tested under stresses of 2–45 MPa and temperatures of −25–160°C. There was a significant variability in the creep curve shape, strain magnitude, and steady-state strain-rate properties. A multivariable linear-regression analysis of the steady-state strain-rate data, using the sinh-law stress representation, indicated two mechanisms distinguished by low- and high-temperature regimes of −25–75°C and 75–160°C, respectively. The sinh-law stress exponent (n) and apparent-activation energy (ΔH) in the −25–75°C regime were 4.4 ± 0.7 kJ/mol and 25 ± 7 kJ/mol (63% confidence intervals), respectively. Those same parameters in the 75–160°C regime were 5.2±0.8 kJ/mol and 95±14 kJ/mol, respectively, for the high-temperature regime. The values of ΔH suggested a short-circuit diffusion mechanism at low temperatures and a lattice or bulk-diffusion mechanism at high temperatures. The stress dependency of the steady-state strain rate did not indicate a strong power-law breakdown behavior or a threshold stress phenomenon. Cracks and grain-boundary sliding were not observed in any of the samples. As the creep temperature increased, a coarsened particle boundary and particle depletion zone formed in the region of fine Ag₃Sn particles that existed between the Sn-rich phase areas. The coarsened particle boundary, as well as accelerated coarsening of Ag₃Sn particles, were direct consequences of the creep deformation process.     

Improving the performance of linear inverse solutions by inverting the resolution matrix

This paper proposes a new strategy for improving the localization capabilities of linear inverse solutions, based on the relationship between the real solution and the estimated solution as described by the resolution matrix equation. Specifically, we present two alternatives based on either the partial or total inversion of the resolution matrix and applied them to the minimum norm solution, which is known for its poor performance in three-dimensional (3-D) localization problems. The minimum norm transformed inverse showed a clear improvement in 3-D localization. The strong dependence of localization errors with the eccentricity of the sources, characteristic of this solution, disappears after the proposed transformation. A similar effect is illustrated, using a realistic example where multiple generators at striate areas are active. While the original minimum norm incorrectly places the generators at extrastriate cortex, the transformed minimum norm localizes, for the example considered, the sources at their correct eccentricity with very low spatial blurring.     

Method based on physical optics for the computation of the radar cross section including diffraction and double effects of metallic and absorbing bodies modeled with parametric surfaces

A method to compute the monostatic radar cross section (RCS) of complex bodies modeled by nonuniform rational B-spline (NURBS) surfaces is presented. The bodies can be covered by any kind of radar absorbing material (RAM) with electric and/or magnetic losses. Physical optics (PO) is used to obtain the scattered field of each surface. Fresnel coefficients are included in the stationary phase method (SPM) in order to take into account the effect of the RAM material. The contribution of diffraction by edges and double effects is also considered, improving the results of the PO approach. The diffraction is computed by the equivalent current method (ECM). A combination of geometrical optics (GO) with PO and ECM is used for the double reflection and double interaction between edges and surfaces respectively. Some simple cases are shown to validate the proposed method. The reliability of the method to analyzing the effect of covering a realistic target with RAM is also illustrated.     

Memory Fault Modeling Trends: A Case Study

In recent years, embedded memories are the fastest growing segment of system on chip. They therefore have a major impact on the overall Defect per Million (DPM). Further, the shrinking technologies and processes introduce new defects that cause previously unknown faults; such faults have to be understood and modeled in order to design appropriate test techniques that can reduce the DPM level. This paper discusses a new memory fault class, namely dynamic faults, based on industrial test results; it defines the concept of dynamic faults based on the fault primitive concept. It further shows the importance of dynamic faults for the new memory technologies and introduces a systematic way for modeling them. It concludes that current and future SRAM products need to consider testability for dynamic faults or leave substantial DPM on the table, and sets a direction for further research.     

Integrated Dual-Display-Based 3G Mobile Phone / Wireless Terminal

In this paper, we describe HW and SW features of the developed prototype of a hybrid 3G mobile phone and wireless terminal, which provides integral video projection onto two VGA/2 displays that, when put side-by-side, form the integrated display with the ratio of the overall width to its overall height, equal to 4:3, so providing the integral video VGA format and enabling visual presentation of standard full-size web pages, PC mainstream SW screens (such as e.g. the ones of e-mail clients), multi-media content etc. When not in use, the displays can be fold back one onto each other, so preserving the industry-standard dimensions of the device. The two displays that share the image provide it with overall resolution of 640 x 480 pixels per inch. The device is driven by Texas Instruments OMAP 2420 multimedia processor with ARM1136 core and Linux operating system. In addition, the device is equipped with specially developped prototypes of unique spring/microgenerator-based battery charger as well as with ultra-thin mountable foil-based QWERTY keyboard.     

Performance of Efficient Signal Detection for LED-ID Systems

In this paper, effects of reader-to-reader interference are investigated for LED identification (LED-ID) system in a multi-reader environment. The LED-ID readers typically use different channels to avoid collision between readers. However, in-channel collision usually happens in terms of interrogation range. A reader-to-reader interference scenario is proposed, and nominal interrogation range of a desired reader is derived from this model. In order to evaluate the LED-ID reader-to-reader interference quantitatively, an efficient detection scheme is proposed and simulated by employing spreading sequence. The spreading sequence is inserted between each user’s frame formats. In the receiver, the desired signal is detected by using correlation among inserted spreading sequences. From simulation results, it is confirmed that the proposed scheme is very effective to enhance reliability of LED-ID communication systems.     

A blind audio steganalysis based on feature fusion

In this paper, we present a blind steganalysis based on feature fusion. Features based on Short Time Fourier Transform (STFT), which consists of second-order derivative spectrum features of audio and Mel-frequency cepstrum coefficients, audio quality metrics and features on linear prediction residue are extracted separately. Then feature fusion is conducted. The performance of the proposed steganalysis is evaluated against 4 steganographic schemes: Direct Sequence Spread Spectrum (DSSS), Quantization Index Modulation (QIM), ECHO embedding (ECHO), and Least Significant Bit embedding (LSB). Experiment results show that the classifying performance of the proposed detector is much superior to the previous work. Even more exciting is that the proposed methodology could detect the four steganography, with 85%+ classification accuracy achieved in all the detections, which makes the proposed steganalysis methodology capable of being regarded as a blind steganalysis, and especially useful when the steganalyzer are without the knowledge of the steganographic scheme employed in data embedding.