SAMVAAD: speech applications made viable for access-anywhere devices

In this work, we present the fabrication of bulk micromachined microbolometers made of amorphous germanium-silicon-oxygen compounds (Ge/sub x/Si/sub 1-x/O/sub y/) grown by reactive sputtering of a Ge/sub 0.85/Si/sub 0.15/ target. We describe the complete procedure for fabricating thermally isolated microbolometers consisting of Ge/sub x/Si/sub 1-x/O/sub y/ sensing films deposited on sputtered silicon dioxide membranes suspended over a silicon substrate. The electrical properties of the sensitive material are set by controlling the deposition parameters of the sputtering technique. Under optimum deposition conditions, Ge/sub x/Si/sub 1-x/O/sub y/ layers with moderate electrical resistivity and thermal coefficient at room temperature as high as -4.2% /spl middot/ K/sup -1/ can be obtained. Isolated structures measured at atmospheric pressure in air have a thermal conductance of 3 /spl times/ 10/sup -6/ W /spl middot/ K/sup -1/ and a thermal capacitance of 6/spl middot/10/sup -9/ W /spl middot/ s /spl middot/ K/sup -1/, yielding a response time of 1.8 ms. Bolometers with an IR responsivity of 380 V /spl middot/ W/sup -1/ and a NEDT of 3.85 K at 100 nA bias current are obtained. The use of sputtered films allows designing a fully low-temperature fabrication process, wholly compatible with silicon integrated circuit technologies.

The surface of pulse septum magnet in HLS was specially coated with Al/sub 2/O/sub 3/ powder by plasma spraying. It was found with such magnet in the injection vacuum chamber the pressure was relatively low. To investigate the mechanics 20 sheets of coating were made (120 /spl times/ 80 /spl times/ 20 mm/sup 2/), adsorption capacity was tested. Pore constitution was studied by N/sub 2/ isotherm method. Results indicated ultimate pressure reduced obviously from 6.4 /spl times/ 10/sup -5/ Pa to 8.6 /spl times/ 10/sup -6/ Pa. Coat adsorption capacity is about 3.68 /spl times/ 10/sup -4/ Pa /spl middot/ 1/cm/sup 2/. BET surface area is 201 m/sup 2//g, Coat is porous and pore is closed at one end. XPS results indicate there are hydroxyl, carboxyl etc., on the surface, and they are most probably related with adsorption.

A new algorithm for the type-II multidimensional discrete cosine transform (MD-DCT) is proposed. Based on the polynomial transform, the rD-DCT with size N/sub 1//spl times/N/sub 2//spl times//spl middot//spl middot//spl middot//spl times/N/sub r/, where N/sub i/ is a power of 2, can be converted into a series of one dimensional (1-D) discrete cosine transforms (DCTs). The algorithm achieves considerable savings on the number of operations compared with the row-column method. For example, the number of multiplications for computing an r-dimensional DCT is only 1/r times that needed by the row-column method, and the number of additions is also reduced. Compared with other known polynomial transform algorithms for MD-DCT and the most recently presented algorithm for MD-DCT, the proposed one uses about the same number of operations. However, advantages such as better computational structure and flexibility in the choice of dimensional sizes can be achieved.

Recent progress in developing large area HTS-coated stainless steel tapes is reported. YBCO films have been grown on IBAD-YSZ buffered 0.1 mm-thick steel tapes using a high-rate pulsed-laser-deposition technique which allows a deposition rate up to 70 nm /spl middot/ m/sup 2//h. The coated conductors (CC) are provided with an optimized shunt layer and current contacts which reduce the generation of Joule's heat. An advanced technique for critical current I/sub c/ measurements was developed. The effects of self-field and time relaxation of current in helically wound tapes are analyzed. In long tapes of 10 m /spl times/ 4 mm, the highest I/sub c/ of 78 A at 77 K was observed. Critical currents of 67-75 A were reproducibly achieved in (8-10) m /spl times/ 4 mm coated tapes. For shorter tapes with a length of 0.2-1 m, critical currents of 317-391 A/cm width of the tape were observed. Fifteen wider CC tapes of 0.6 m /spl times/ 43 mm with I/sub c/ = 700 A have been manufactured and employed in newly developed fault current limiters with a nominal current of 3 kA. Critical current densities J/sub c/ = (1.3-2.5) MA/cm/sup 2/ at 77 K were observed in YBCO films. The CC tapes exhibit favorable behavior under axial stress and sufficiently small ac losses.

This paper presents the optimal guaranteed performance for a multiple-antenna wireless compound channel with M antennas at the transmitter and N antennas at the receiver on a Ricean fading channel with a static specular component. The channel is modeled as a compound channel with a Rayleigh component and an unknown rank-one deterministic specular component. The Rayleigh component remains constant over a block of T symbol periods, with independent realizations over each block. The rank-one deterministic component is modeled as an outer product of two unknown deterministic vectors of unit magnitude. Under this scenario, to guarantee service, it is required to maximize the worst case capacity (min-capacity). It is shown that for computing min-capacity, instead of optimizing over the joint density of T /spl middot/ M complex transmitted signals, it is sufficient to maximize over a joint density of min{T, M} real transmitted signal magnitudes. The optimal signal matrix is shown to be equal to the product of three independent matrices - a T /spl times/ T unitary matrix, a T /spl times/ M real nonnegative diagonal matrix, and an M /spl times/ M unitary matrix. A tractable lower bound on capacity is derived for this model, which is useful for computing achievable rate regions. Finally, it is shown that the average capacity (avg-capacity) computed under the assumption that the specular component is constant but random with isotropic distribution is equal to min-capacity. This means that avg-capacity, which, in general, has no practical meaning for nonergodic scenarios, has a coding theorem associated with it in this particular case.

A bipolar fuzzy set theory is presented for cognitive modeling and multiagent decision analysis. Firstly, notions of bipolar fuzziness are introduced. Secondly an interval-based bipolar fuzzy logic is defined which generalizes a real-valued bipolar fuzzy logic by allowing interval-based linguistic variables x and y to be substituted into (S, =, V, /spl otimes/) or (S, =, /spl cup/, /spl odot/) where S={/spl forall/(x,y)|(x,y)/spl isin/([-1,0]/spl times/[0,+1])}. Thirdly, a fuzzy number-based bipolar logic is presented which. Further generalizes the interval-based model by allowing /spl alpha/-level fuzzy number-based linguistic variables x and y to be substituted into (S, =, V, /spl otimes/) or (S, =, /spl cup/, /spl odot/), S={/spl forall/(x,y)|(x,y) maps ([-1,0]/spl times/[0,+1]) to [0,1]}. Bipolar fuzzy set operations of disjunction composition (V-/spl otimes/), union-composition (/spl cup/, /spl odot/), are proved commutative and associative; V respect to /spl otimes/ and /spl cup/ respect to /spl odot/ are proved distributive. It is shown that a interval-based bipolar variable is a nesting of a real-valued bipolar variable; a trapezoidal-fuzzy number-based bipolar variable is an 2-level nesting of an interval-based bipolar variable; and an /spl alpha/-level (/spl alpha/ is an integer) fuzzy number-based bipolar variable is an /spl alpha/+1 level nesting of an interval-based bipolar variable. Based on the nesting features, it is proved that /spl alpha/-level fuzzy number-based bipolar operations can be converted to interval-based and then real-valued bipolar operations. The conversions lead to significant computational simplification on bipolar fuzzy relations. Major advantages of the bipolar fuzzy set theory include: (1) it formalizes a unified approach to polarity and fuzziness; (2) it captures die bipolar or double-sided (negative and positive, or effect and side effect) nature of human perception and cognition; and (3) it provides a basis for bipolar cognitive modeling and multiagent decision analysis. >

An important challenge of integrating pervasive devices into Grid environment to enhance pervasive device capabilities is that pervasive devices need to locate, find, select and invoke the appropriate Grid services in an autonomic and flexible way. However, at this stage, both Grid service description and discovery standards are not very sophisticated. Semantic web technology benefits the concept of Grid services on pervasive devices by adding machine- processable explicit knowledge into the interaction between pervasive devices and Grid services. In this paper, we have presented a semantic-based Grid service discovery mechanism to support pervasive device accessing Grid services. In order to protect personal privacy in the pervasive computing environment, a service discovery restricting mechanism is also built to ensure the service can automatically be hidden for unauthorized users.

This paper discusses the receiver design of a destination node supporting multiple antennas for an alternate-relaying decode-and-forward (DF) cooperative communication system. We exploit the structure of the received signal to develop an optimal data detection algorithm at the destination. It is shown that the optimal algorithm can be implemented by parallel detectors, each based on a family of Bahl, Cocke, Jelinek and Raviv (BCJR) algorithms. The proposed optimal algorithm requires to receive and store all packets before performing data detection. To avoid this, a sub-optimal algorithm is also proposed. Unlike the optimal algorithm, the sub-optimal one exploits two consecutive received packets to detect one packet. It turns out that the sub-optimal algorithm has less reduced delay, complexity, memory size and bandwidth loss with a slight increase of the bit-error-rate. The detection performance of the proposed algorithms is evaluated via Monte Carlo simulations, and the results demonstrate their effectiveness.

It is proved that if the nonempty intersection of bounded closed convex sets A \ B is contained in (A u F) ( (B u F) and one of the following holds true: (i) the space X is less-than-three dimensional, (ii) A ( B is convex, (iii) F is a one-point set, then A \ B A u F or A \ B B u F (Theorems 2 and 3). Moreover, under some hypotheses the characterization of A and B such that A \ B is a summand of A ( B is given (Theorem 3). In this paper we consider the inclusion A\B (AuF)((B uF) which plays a central role in proving criterion of convex minimality of pairs of bounded closed convex sets (12), (13). Minimal pairs of compact convex sets were investigated in a series of papers (2), (4), (5), (10), (12), and others. Pairs of compact convex sets naturally arise in quasidierential

Some criteria for minimality for a pair of compact convex subsets of a real locally convex vector space are proved. Moreover several examples are given.

The security of the Internet of Things (IoT) depends on strong cryptographic functions that require extensive computation and resources. The security of Internet of Things (IoT) relies on the use of strong cryptographic functions that demand extensive computation and resources. Therefore, the selection of a cryptographic system is influenced by the computational and communicational capabilities of IoT devices, including their energy requirements, memory constraints, and execution time. This paper aims to develop a lightweight and secure encryption algorithm for IoT applications, focusing on advancing cryptanalysis techniques. We propose a new lightweight algorithm named enhanced 3D RECTANGLE, designed to deliver robust security for IoT applications and optimized for cell phones with minimal memory usage, low power consumption, and efficient performance. The RECTANGLE block cipher was chosen for this research due to its high efficiency and speed relative to other lightweight algorithms, despite some security issues. The proposed enhanced 3D RECTANGLE algorithm improves confusion and diffusion properties through a new 3D array block rotation method for 4x4 plaintext, based on a 128-bit key and 16 rounds. Additionally, we designed a 4x4 composite S-Box with a Galois field pipelining structure, offering a more advanced solution compared to the Look-Up Table method. The cryptanalysis, avalanche effect, and bit error rate tests were conducted to verify the security strength of the proposed algorithm. The proposed algorithm was evaluated against two existing algorithms, RECTANGLE and Extended 3D RECTANGLE. The enhanced 3D RECTANGLE algorithm provides better cryptanalysis, demonstrating a 40% avalanche effect and achieving a bit error rate (BER) of 31%, indicating its greater effectiveness compared to the other two lightweight algorithms.

Event Abstract Back to Event Multi-modal optimization techniques for improving qualitative features of biophysical neural models Robert Clewley1, 2 and Mirza Dobric2* 1 Georgia State University, Neuroscience Institute, United States 2 Georgia State University, Department of Mathematics and Statistics, United States We present a novel computational technique that enables more efficient optimization of qualitative features in biophysical neural models. In particular, we extend the idea of multiple objective optimization for a single comparison modality (such as comparison of individual voltage traces) [1] into multiple modalities. For instance, features may be defined in terms of measurements from different experimental scenarios, and might include not only action potential spike shape characteristics (Cf. [1, 2]), but also complex features such as the frequency response curve (as a function of injected current), and phase response curve (as a function of perturbation time). The benefit of multiple feature modalities is to provide additional ways to distinguish solutions that might otherwise appear similarly fit in the restrictive view of a single modality. This is often due to relative insensitivities of some parameters to features in a single modality, or parameter co-variation/modulation [2], which creates an ill-posed optimization problem (poor gradients, local minima, or multiple global minima in the fitness landscape). Thus, for any given parameter choice, an evaluation of model fitness might involve multiple test scenarios to be executed. We use an implementation in the PyDSTool software [3] to demonstrate the ease with which this multi-modal approach can be prepared and embedded in conventional gradient-based or global optimization algorithms. We show that the technique improves detailed models with many parameters over heterogeneous data sets that contain noise and variability in underlying conditions, for which methods based on single modalities fail.

The measurement of spatial cross sections of ultrasound pressure fields is an essential element of exposimetry of ultrasonic medical equipment. An optical technique is presented that allows the two-dimensional (2-D) determination of ultrasound pressure using an optical multilayer hydrophone in which a laser beam with suitable wavelength is partially reflected from a dielectric optical multilayer system. By detecting the change in reflectivity of the multilayer coating induced by the incident ultrasound, the pressure time waveform can be determined. A 2-D data acquisition covering an area of at least 15 mm x 5 mm was realized by two complementary approaches. A serial detection scheme was set up by scanning the sensing point across the area of interest by a micromechanically engineered scanning mirror and acquiring pressure time waveforms sequentially and pointwise. This allows the measurement of repeating ultrasonic waveforms with a spatial resolution of better than 70 microm and a minimal detectable pressure of 50 kPa (bandwidth: 50 MHz) in a few seconds. In an alternative approach exploiting the parallel processing capabilities of a charge-coupled devices (CCD) camera chip, the probe was strobe-illuminated by a large-diameter collimated beam of a pulsed laser diode. The 2-D pressure distribution at a particular moment was derived from captured reflectivity distributions with a spatial resolution of 75 microm. By successive delaying of the laser pulse with respect to the ultrasound pulse, the complete 2-D pulse waveform was acquired with high spatial resolution. Measurement results on ultrasound fields from plane and focusing transducers are presented and compared to simulation results. Individual advantages and drawbacks of both approaches are discussed. A combined setup merging both detection schemes into a single device was developed and represents a milestone on the way toward constructing an optical ultrasound measuring camera.

There are many commercial applications which require high RF CW power in the kilowatt to megawatt range. To date, these high RF power requirements can only be accomplished by incorporating traveling wave tubes (TWT) or inductive output tubes (IOT). However, recent advances in the output power capability of SiC power devices for radar systems now suggest that high power SiC static induction transistors (SIT) can be used to develop a 10 kW solid state RF power amplifier. From analysis of existing high power RF amplifiers, development of a transistor cell that can produce 10 W CW output power would provide the necessary building block for assembly of a 10 kW power amplifier. As a first step in this development, existing ion implanted SiC SIT device cells fabricated at Northrop Grumman were packaged and tested for CW operation at 750 MHz. Identical transistor die from a single wafer of ion implanted SIT devices were selected, each having a layout of 10 device cells per die, with each cell having a gate periphery equal to 1.30 cm, and an active area of 2.92 /spl times/ 10/sup -4/ cm/sup 2/. To minimize heating under CW operation, only 10 cells were bonded into a transistor package. This was accomplished by attaching only 2 die to a package, and wire bonding every other cell in each die. In this manner, only 5 cells from each die were connected together, and the remaining 5 cells were not used, thus allowing for improved heat spreading.

Heterogeneous systems equipped with traditional processors (CPUs) and graphics processing units (GPUs) have enabled processing large data sets. With new programming models, such as OpenCL and CUDA, programmers are encouraged to offload data parallel workloads to GPUs as much as possible in order to fully utilize the available resources. Unfortunately, offloading work is strictly limited by the size of the physical memory on a specific GPU. In this paper, we present Virtual Address Space for Throughput processors (VAST), an automatic GPU memory management system that provides an OpenCL program with the illusion of a virtual memory space. Based on the available physical memory on the target GPU, VAST does the following: automatically partitions the data parallel workload into chunks; efficiently extracts the precise working set required for the divided workload; rearranges the working set in contiguous memory space; and, transforms the kernel to operate on the reorganized working set. With VAST, the programmer is responsible for developing a data parallel kernel in OpenCL without concern for physical memory space limitations of individual GPUs. VAST transparently handles code generation dealing with the constraints of the actual physical memory and improves the re-targetability of the OpenCL with moderate overhead. Experiments demonstrate that a real GPU, NVIDIA GTX 760 with 2 GB of memory, can compute any size of data without program changes achieving 2.6× speedup over CPU exeuction, which is a realistic alternative for large data computation.