Output Of Block Research Articles

키유도함수의 통계적 난수성 평가 방법

암호시스템에 사용되는 알고리즘의 기본적인 안전성 평가 항목은 난수성이다. 미국의 표준기술원 NIST는 차세대 암호알고리즘 AES를 선정하는 과정에서 블록암호의 난수성을 통계적으로 평가할 수 있는 패키지를 제안하였다. 이 패키지는 입출력 길이가 동일한 함수인 블록암호에 적합하도록 구성되어 있으므로 대부분 확장된 출력 길이를 갖는 키유도함수의 난수성 평가에 그대로 적용하는 것은 무리가 있다. 본 논문에서는 입력 길이보다 확장된 다중 블록을 출력하는 대표적인 암호 구성 요소인 키유도함수에 적합한 통계적 난수성 평가 방법으로 NIST의 방식을 개선한 것을 제안한다. 그리고 제안된 방법에 의하여 3GSM과 NIST에서 표준으로 권고하고 있는 키유도함수에 대한 통계적 난수성 평가결과를 제시한다. Randomness is a basic security evaluation item for the most cryptographic algorithms. NIST has proposed a statistical test suit for random number generators for cryptographic applications in the process of AES project. However the test suit of NIST is customized to block ciphers which have the same input and output lengths. It needs to revise NIST's test suit for key derivation functions which have multiple output blocks. In this paper we propose a revised method of NIST's statistical randomness test adequate to the most key derivation functions and some experimental results for key derivation functions of 3GSM and NIST.

Very-low-complexity concurrent error detection for transform-based filters

A very-low-complexity concurrent error detection technique for filters implemented in the frequency domain using the fast Fourier transform and the overlap-add method is presented. The proposed approach checks the first or last sample of every output block by comparing it with the equivalent value calculated in the time domain. The check requires only one additional multiplication per output block. Thus, the computational complexity of the check is negligible. It is shown that the method is capable of detecting a significant percentage of errors.

The mushroom body

What is a mushroom body? The mushroom body is a prominent and striking structure in the brain of several invertebrates, mainly arthropods. It is found in insects, scorpions, spiders, and even segmented worms. With its long stalk crowned with a cap of cell bodies, a GFP-labeled mushroom body certainly lives up to its name (Figure 1). The mushroom body is composed of small neurons known as Kenyon cells, named after Frederick Kenyon, who first applied the Golgi staining technique to the insect brain. The honey bee brain, for instance, contains roughly 175,000 neurons per mushroom body while the brain of the smaller fruit fly Drosophila melanogaster only possesses about 2,500. Kenyon cells thus make up 20% and 2%, respectively, of the total number of neurons in each insect's brain. Kenyon cell bodies sit atop the calyx, a tangled zone of synapses representing the site of sensory input. Projecting away from the calyx is the stalk comprised of Kenyon cell axons carrying information away to the output lobes.

Color Conversions In The Transform Domain

A noval novel technique is described for high speed color conversions for JPEG-compressed images. The color conversion is processed in the transform domain instead of the traditional spatial domain. Only the input DC coefficients of the multiple color components are processed through the traditional table lookup to create output DC coefficients. Given each output color component's DC value, the linearity of its 63 AC coefficients is determined and their transform domain scaling functions are looked up in a 1-D table as a function of only the component output DC term. For n-dimensional input color space to m-dimensional output color space conversion, n component blocks create m output blocks. These blocks can be inverse DCTed to create spatial domain data or requantized and entropy encoded to create JPEG compressed data. Abort criteria also have been developed to determine when the traditional spatial domain interpolation needs to be done.

Noncoherent block detection in the presence of DC offset

In this paper, we deal with noncoherent detection of a digitally phasor block-modulated signal in the additive white Gaussian noise channel when a direct-current (DC) offset is present in the receiver baseband processing. By processing the received baseband signal block by block, a generalized linear transform is used to remove the offset prior to data detection, thereby releasing the succeeding detection process from the threat of DC offset. Operating on transform output blocks, a generalized maximum-likelihood scheme is developed for noncoherent data detection without a priori knowledge of channel amplitude and phase. When all the signaling blocks are confined within the space expanded by the basis vectors obtained from the onset-removal transform matrix, the proposed detection scheme can exploit the advantage of performing data detection and estimation on channel amplitude and phase jointly in the maximum-likelihood sense. It is analytically shown that the block detection scheme provides the bit error performance asymptotically approaching that of the corresponding ideal coherent phase-shift-keyed (PSK) detection in the absence of DC offset when the block length is increased. An iterative detection scheme is also modified from the block detection scheme to simplify the realization complexity. Both block and iterative detection schemes are shown to outperform the conventional training-sequence-aided PSK detection scheme under the same transmission throughput efficiency

Parasitoid wasp sting: A cocktail of GABA, taurine, and β‐alanine opens chloride channels for central synaptic block and transient paralysis of a cockroach host

The wasp Ampulex compressa injects venom directly into the prothoracic ganglion of its cockroach host to induce a transient paralysis of the front legs. To identify the biochemical basis for this paralysis, we separated venom components according to molecular size and tested fractions for inhibition of synaptic transmission at the cockroach cercal-giant synapse. Only fractions in the low molecular weight range (<2 kDa) caused synaptic block. Dabsylation of venom components and analysis by HPLC and MALDI-TOF-MS revealed high levels of GABA (25 mM), and its receptor agonists beta-alanine (18 mM), and taurine (9 mM) in the active fractions. Each component produces transient block of synaptic transmission at the cercal-giant synapse and block of efferent motor output from the prothoracic ganglion, which mimics effects produced by injection of whole venom. Whole venom evokes picrotoxin-sensitive chloride currents in cockroach central neurons, consistent with a GABAergic action. Together these data demonstrate that Ampulex utilizes GABAergic chloride channel activation as a strategy for central synaptic block to induce transient and focal leg paralysis in its host.

On compensator design for linear time-invariant dual-input single-output systems

This paper presents a new method for the design of compensators for linear time-invariant dual-input/single-output (DISO) systems in continuous time or discrete time. The new method reduces the problem to two single-input/single-output (SISO) design problems, which are well suited to frequency-response design techniques. The first part of the method is the design of a stabilizing compensator for an auxiliary feedback system. The auxiliary compensator parameterizes the two output blocks of the single-input/dual-output compensator such that the zeros of the parallel system formed by cascade of the compensator with the plant are stable. The auxiliary compensator also determines the relative contribution to the output of the two parallel subsystems of the DISO system. The second SISO compensator design is used to ensure that the feedback system is stable and that performance and robustness specifications are achieved. This paper includes a discrete-time-design example for a dual-stage actuator system for a disk drive including implementation results. Straightforward extensions for multi-input/single-output systems are discussed.

Results of allograft aortic valve replacement for complex endocarditis

Methods: Between November 1985 and July 1995, 36 patients underwent allograft aortic valve replacement for endocarditis. The mean age of the 29 men and seven women was 53 years (range 25 to 79 years). Previous procedures included mechanical ( n = 9), bioprosthetic ( n = 5), and allograft ( n = 2) aortic valve replacement, aortic valvotomy ( n = 1), and orthotopic heart transplantation ( n = 1). Infecting organisms were Staphylococcus and Streptococcus species in 69% of patients and fungi in 6%. Intraoperative findings demonstrated valvular vegetations ( n = 25), annular abscesses ( n = 25), and cusp destruction ( n = 13). Complex reconstruction of the aortic anulus was required in 25 patients, and associated procedures included mitral valve repair ( n = 2), mitral valve replacement ( n = 3), coronary artery bypass grafting ( n = 8), repair of ventricular septal defect ( n =4), left ventricular aneurysmectomy ( n = 1), and repair of atrial septal defect ( n = 1). Allograft valve insertion was performed by the scalloped technique in seven, intraaortic cylinder technique in 19, and allograft aortic root replacement in 10. Results: Follow-up was 100% complete at a mean of 2.6 ± 2.8 years after valve replacement. Operative mortality was 13.8%. Complications included low cardiac output ( n = 10), bleeding ( n = 2), myocardial infarction ( n = 1), stroke ( n = 1), renal insufficiency ( n = 2), respiratory insufficiency ( n = 3), and heart block ( n = 8). Late echocardiogram (mean 2.6 ± 1.8 years) demonstrated grade III/IV aortic regurgitation in five patients. There were seven late deaths (five cardiac, not valve-related; two noncardiac). No patient has had recurrence of endocarditis. Actuarial survival at 5 years was 53.1% ± 11.5%. Univariate analysis demonstrated prosthetic valve endocarditis to adversely affect late survival ( p = 0.04). Cumulative risk of reoperation at 5 years was 8.0% ± 5.6%. Conclusion: Allograft aortic valve replacement facilitated reconstruction of complex aortic valve endocarditis with a low reoperation rate and no recurrent endocarditis in this series.

Overlapped block digital filtering

Block digital filtering has been suggested to increase the parallelism of computation and to reduce the computational complexity of digital filtering systems. In this paper the block processing concept is generalized by considering overlapped input and/or output blocks. As an overlapped block digital filter is, in general, a shift-varying system, the conditions for its shift-invariant operation have been developed. These conditions have been exploited to derive computationally efficient shift-invariant block structures. Two types of fast FIR filtering algorithms using the overlapped block filter structures are derived. One is based on the adaptation of fast short-length linear convolution algorithms and the other is based on DFT algorithms. These algorithms not only reduce the computational complexity of filtering operations but also offer modular and parallel structures. Finite wordlength effects of FIR filters implemented using the overlapped block filter structure are also investigated.

Novel sorting network-based architectures for rank order filters

This paper presents two novel sorting network-based architectures for computing high sample rate nonrecursive rank order filters. The proposed architectures consist of significantly fewer comparators than existing sorting network-based architectures that are based on bubble-sort and Batcher's odd-even merge sort. The reduction in the number of comparators is obtained by sorting the columns of the window only once, and by merging the sorted columns in a way such that the number of candidate elements for the output is very small. The number of comparators per output is reduced even further by processing a block of outputs at a time. Block processing procedures that exploit the computational overlap between consecutive windows are developed for both the proposed networks.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

針路推定ニューラルネットワークシステム

This paper concerned with a picture recognition neural network system for course estimation. A subject of recognition is a picture of target ship which can be seen in the bridge. This system consists of four functional blocks ; a picture input block, a picture processing block, a picture recognition neural network block and an output block. The neural network topology is four-layered network, which includes Tschebyscheff layer. Pictures of one fiftieth scale model of the Shioji-maru, a training ship, are used for supervised training pictures. Recognition ratio which is equal to similarity of a test picture and the supervised training picture is calculated by the neural network outputs. And an estimated course is decided by distribution of the recognition ratios. The summary of the results are shown below. (1) Possibility of course estimation which makes use of the picture recognition neural network is found. (2) Accuracy of course estimation is about ±18 degree. (3) Time required of course estimation is about 4.5 second using a 22 MIPS computer. (4) If the picture of different style of ship from the Shioji-maru as the supervised training picture is inputted to this system, course estimation capacity is insufficient level. (5) Information of a navigation image understanding system building is obtained.

An echo canceller with a block-implemented learning identification algorithm

Characteristics of an echo canceller with use of a block-implemented learning identification algorithm are examined through an approximate analysis and computer simulation experiments. Block digital signal processing, which involves the calculation of a block or finite set of system output from a block of input, is a promising technique to allow efficient use of parallel processors. The echo return loss enhancement, defined as a performance index of the echo canceller, is represented by an approximate equation as a function in the signal-to-noise ratio of a circuit and an acceleration coefficient for updating the echo-path impulse response estimates. This approximate analytical expression is observed to agree well with the results from simulation experiments.

On Output Decomposed Linearization

This paper treats two kinds of linearization and simultaneous output block decoupling problems. Necessary and sufficient conditions are obtained for both output decomposed linearization and output decomposed partial linearization. For the first problem, under the same assumptions of [6], new result simplifies the conditions of [6].

Digital teleprotection units. A technology overview

The authors describe a generic digital teleprotection unit (DTU) and discuss the technical characteristics of current commercial systems. A generic DTU contains a transmitter section, a receiver section and a status section. Some DTUs have a unidirectional option eliminating either the receiver section or the transmitter section. The transmitter section contains an input block, a transmitter logic block and a transmitter block. The receiver consists of a receiver block, a receiver logic block and an output block. The status section contains a selftest block and an alarm block. These subsystems are discussed. a comparison is made between DTUs and their analogue counterparts in the area of transfer trip delay. A direct transfer trip system utilizing redundant DTUs is proposed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Potential Profitability and Decreased Consumer Welfare Through Manufacturers' Cents-Off Coupons

It seems peculiar that so little attention has been paid to potential adverse effects of manufacturers' cents-off couponing policies especially considering the volume and cost of their distribution. In fact, it has been reported that in 1985 a total of $180 billion worth of coupons was issued. The majority were distributed blindly--approximately 60 percent in freestanding inserts, 31 percent printed in newspapers and magazines, and the remaining nine percent by mail or attached to the product package itself. Thus, given the reported four percent redemption rate, approximately $7.2 billion worth of coupons was used in 1985 (Clements 1986). On the cost side, one survey estimated the cost of freestanding newspaper inserts to be approximately $7 per thousand with the cost increasing for other types of distribution (Clements 1986). If it is assumed that the average coupon value is $0.30 and the cited cost figure is employed, a low estimate of the fixed cost of coupon distribution in 1985 would be $4.2 billion. Clearly, even this rough estimate demonstrates that couponing costs are not a trivial use of resources. Although the formal model of third-degree price discrimination employed in this paper occupies a time-honored position in the literature of economics, its implications in this area appear to have been widely ignored by consumer advocates. The fact that potential losses resulting from cents-off couponing are is some sense voluntary (all consumers have the option of redeeming coupons) may account for this lack of interest because this type of price discrimination is not prohibited under the Robinson-Patman Act. Also, the view that manufacturers' cents-off coupons are mainly promotional may alleviate concern over the types of losses discussed here. This paper examines the potential magnitude of the increase in oligopolistic manufacturers' profits due to a policy cents-off couponing and the resulting changes in consumer welfare and resource allocation. In addition, evidence is presented in support of the hypothesis that observed couponing policies of U.S. manufacturers are motivated by their desire to increase profits through third-degree price discrimination--a practice that results in welfare losses to consumers. Third-degree price discrimination involves the ability of a producer to separate customers into two (or more) distinct demand groups and charge two (or more) different prices to members of each group. In contrast, first-degree price discrimination or perfect price discrimination involves selling each unit of a good at its demand price with the last unit being sold at marginal cost. Second-degree price discrimination or block pricing entails selling the first block of output associated with the price of say, [P.sub.1] or greater at [P.sub.1], the second block associated with a demand price less than [P.sub.1] but greater than or equal to [P.sub.2] at [P.sub.2]([P.sub.1] > [P.sub.2]), and so on until the last block is sold at marginal cost. While some of the conclusions of this paper have been dealt with by other researchers (Narasimhan 1984; Phlips 1983; Robinson 1933; Schmalensee 1981; Tirole 1988; Vilcassim and Wittink 1987; Yamey 1974), the approach taken here differs in that it attempts to quantify the probable magnitudes of the welfare effects and profit potential of oligopolistic manufacturers' couponing policies within the framework of a third-degree price discrimination model. An innovative simulation approach which offers a useful alternative methodology for future research is introduced. Moreover, the idea that products redeemed with a coupon carry additional marginal cost of redemption is incorporated into the analysis. As is expected, this will lower the quantity produced when compared to the outcome under single oligopolistic pricing. This investigation will be limited to markets in which products are already well established and the demand curves facing each firm in a market will be assumed to be constant. …

A flexible module library for custom DSP applications in a multiprocessor environment

The module library for the Cathedral-II synthesis environment is discussed. The underlying architectural style of the environment is defined as a hierarchical composition of flexible and parameterizable data paths, microcoded control units, interprocessor communication protocols, and input/output interfaces. A data path is called an execution unit (EXU), which consists of three parts: an input block, an output block, and a core. Only the core varies for the different EXUs. The topology and functionality of an EXU can be influenced by a set of parameters. The module library consists of two parts, a leaf-cell library and a procedure library, to place and interconnect the leaf cells to create functional building blocks that compose one EXU. The EXUs are guaranteed to work at 10 MHz. The described modules have been implemented and tested. The main features of this system are a very powerful parameterization, the technology independence of the CAD tools, and the generation speed of the modules. The current library is specially dedicated towards application-specific IC (ASIC) customized processors, although it can be used for more hardwired architectures, oriented towards higher throughput.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A practical reliability metric for block codes used on binary-input channels

A reliability metric (RM) for a block code is defined to be a function that operates on both the decoder input (a block of channel output) and the decoder output (the codeword estimate) and produces a real number as a measure of the reliability of the decoder decision. The best RM has the disadvantage of depending on the codeword probabilities. Thus, the ideal RM is defined as the value that would be computed for equally likely codewords. The implementation of the ideal RM is too costly for most applications. The author proposes an easily implemented RM for binary-input memoryless channels (for state-observable channels with a freely evolving state such as some fading channels) when the codewords consist of n 2/sup m/-ary symbols, each of which is transmitted serially by m uses of the channel. Simulation results for some BCH codes and some Reed-Solomon codes used in a simple ARQ system show that the proposed RM performs nearly as well as the ideal RM and much better than a previously proposed practical RM. >

Involvement of excitatory amino acids in neurotransmission of inspiratory drive to spinal respiratory motoneurons

The role of excitatory amino acids in the transmission of bulbospinal respiratory drive to spinal motoneurons was investigated in the in vitro and in vivo spinal cord of the rat. In vitro studies were performed with a preparation of neonatal rat brain stem and spinal cord that spontaneously generates rhythmic respiratory drive to spinal respiratory motoneurons. This in vitro system allowed examination of the effects of pharmacological agents on spinal motoneuron activity, without perturbing the activity of bulbospinal neurons transmitting the respiratory drive. The amplitude of spontaneous motor discharge in spinal ventral roots containing phrenic and intercostal motor axons was reduced in a dose-dependent manner by antagonists to excitatory amino acids acting at NMDA receptors [D,L-2-amino-5-phosphonovaleric acid (D,L-AP5)] and non-NMDA receptors [kynurenic acid, gamma-D-glutamylglycine, gamma-D-glutamyltaurine, and L- and D,L-2-amino-4-phosphonobutyric acid (L-AP4,D,L-AP4)]. The order of potency of the antagonists for complete block of the motor output was L-AP4 greater than D,L-AP4 greater than kynurenic acid greater than gamma-D-glutamylglycine greater than D,L-AP5 greater than or equal to gamma-D-glutamyltaurine. Amino acid uptake inhibitors augmented the spontaneous motoneuron activity, further confirming the involvement of endogenous excitatory amino acids in transmission of respiratory drive. The results obtained in vitro with AP4, kynurenic acid, and amino acid uptake inhibitors were confirmed in vivo by bathing segments of the rat spinal cord in situ with solutions containing antagonists and uptake inhibitors. The present results suggest that an important component of the neurotransmission of bulbospinal respiratory drive involves endogenous excitatory amino acids acting at AP4-sensitive sites and other non-NMDA (quisqualate/kainate) receptors. The bulbospinal-spinal respiratory motoneuron synapse may provide a convenient model synapse in the spinal cord for detailed analysis of mechanisms underlying excitatory amino acid-mediated synaptic transmission of motor drive.

Two-dimensional block implementation of symmetric half-plane recursive digital filters

Two-dimensional (2-D) block implementation of 2-D symmetric half-plane (SHP) recursive filters is considered. A 2-D block-recursive equation is first derived. It is found that all the coefficient matrices associated with the input and previous output blocks are Toeplitz in their submatrices. Therefore, high-speed convolution algorithms can be utilized to perform the associated submatrix-vector multiplications. The block implementation using the fast Fourier transform is compared to the direct implementation as regards computational requirements.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Array block implementation of two-dimensional asymmetric half plane IIR digital filters

Two block implementation schemes for the simultaneous computation of rectangular blocks of output data (as opposed to linear blocks in a row) of 2-D half plane IIR digital filters are derived. The first scheme directly manipulates the half plane scalar filter to obtain the block equation. Here, the basic noncomputable block equation derived by Mertzios (1984) is utilized as a starting point. If M × N is the order of the filter ( M in z 1− and N in z 2-direction), then the number of terms in the resulting block equation depends on N even if the array size is L 1 × L 2 ⩾ M × N. This is in contrast to the quarter plane filter in which the number of terms of the block implementation is always eight as long as the array size is L 1 × L 2 ⩾ M × N. Also, the caution to be exercised in this method while computing the output block near the border of the conical output array is pointed out. The second scheme deals with mapping the 2-D half plane filter into the 2-D quarter plane filter and then implementing the resulting quarter plane filter in the block. The resulting quarter plane scalar filter has size M × N( M + 1). Therefore, the array size should be L 1 × L 2 ⩾ M × N( M + 1) in order to have only eight terms in the block realization.