Various constructions of authentication codes using spaces related to the general linear group have been proposed and analyzed. In the paper the authors describe two new constructions of Cartesian authentication codes using symplectic spaces. This illustrates the feasibility of codes from spaces based on geometries of the other classical groups.

The P-context algorithm as introduced by Weinberger and Seroussi (see IEEE Trans. Inform. Theory, p.1697-1706, 1996) offers a way to reduce the parameter description costs. This paper concerns a possible improvement of the P-context algorithm. By using weighting techniques an accurate redundancy bound is derived and a possible implementation is proposed.

A windmill generator is a high-speed sequence generator capable of producing blocks of v consecutive symbols in parallel. It consists of v feedback-shift registers linked into a ring. The sequences are identical to those produced by a linear feedback-shift register with feedback polynomial of the special ('windmill') form f(t) = α(tv) - tLβ(t-v), where α(t) and β(t) are polynomials of degree less

Frontal cortex activity is reduced in the left hemisphere during depression. Transcranial direct current stimulation is a noninvasive neuromodulation technique that can increase frontal cortex activity. Therapy based on transcranial Direct Current Stimulation and positive psychology therapy was applied for improving patients' quality of life. The present study compared three conditions of subjects

Data from experiments on the phenomenon of recognition failure of recallable words show moderate dependence between recognition and recall. TECO, a connectionist theory, is proposed to account for the phenomenon. Cued recall is assumed to be cued with the cue word and the event. Recognition is assumed to be cued with the event and the copy cue. Moderate dependence is predicted because recall and r

Forgetting in long-term memory, as measured in a recall or a recognition test, is faster for items encoded more recently than for items encoded earlier. Data on forgetting curves fit a power function well. In contrast, many connectionist models predict either exponential decay or completely flat forgetting curves. This paper suggests a connectionist model to account for power-function forgetting c

In this comment we show that a recently proposed public key cryptosystem is not safe for most of the practical cases. Furthermore, it is shown that the security of this system is closely connected with the problem of computing logarithms over a finite field.

The long standing question whether the free distance of fixed rate convolutional codes is as good as the Costello bound was almost solved by K.S. Zigangirov and J.L. Massey (1987). They proved that this is indeed the case for codes with long branch length and rates 2/c, c>or=5. It is shown that there exist fixed convolutional codes of rate 2/4 whose free distance d/sub free/ meets the Costello bou

The windmill technique has several practical advantageous over other techniques for high-speed generation or blockwise generation of pn-sequences. In this paper we generalize previous results by showing that if f(t)=α(t v) − β(t −v)t L is the minimal polynomial of a pn-sequence, then the sequence can be generated by a windmill generator. For L = 1,..127, and ν = 4, 8, 16 such that L ≡ ±3 mod 8 no

Wetlands are integral components of our natural environment since they provide many critical ecosystem services to humanity, such as water purification, climate change mitigation, flood control, and biodiversity. Although wetlands can convey resilience to some degree of changes, they might be vulnerable to climate change. Altered hydrology and rising temperatures can turn the wetland services into

Empirical forgetting curve data have been shown to follow a power function. In contrast, many connectionist models predict either an exponential decay or flat forgetting curves. This paper simulates power function forgetting curves in a Hopfield network modified to incorporate the more biologically realistic assumptions of bounded weights and a distribution of learning rates. The modified model pr

This thesis is a study of the development of the Chinese public accounting profession since China launched the “Reform and Opening-up” policy in 1978. The current, established theoretical representations of accounting professionalisation in China are predominantly underpinned by Gramsci’s (1971) hegemony perspective. Such a hegemony perspective has led to a one-sided understanding of accounting pr

Many industrially relevant emulsification devices are of the high-energy type, where drop deformation and subsequent breakup, take place due to intense turbulent fluid–drop interactions. This includes high-pressure homogenizers as well as rotor-stator mixers (also known as high-shear mixers) of various designs. The stress acting on a drop in a turbulent flow field varies over time, occasionally re

The frequently assumed "freshness" constraint on the source states in multiple authentication schemes is not necessary if one allows the encoding rule to change between subsequent transmissions. In the paper it is shown that the main existing lower bounds on the probabilities of successful attack on multiple authentication schemes also hold for this new setup. Furthermore, Stinson's (1988) bound f

The threat of hardware Trojans has been widely recognized by academia, industry, and government agencies. A Trojan can compromise security of a system in spite of cryptographic protection. The damage caused by a Trojan may not be limited to a business or reputation, but could have a severe impact on public safety, national economy, or national security. An extremely stealthy way of implementing ha

In this paper we consider cipher systems that provide both secrecy and security for a given number of (subsequent) transmissions. We show that there exists a broad class of situations in which we can do better (less key requirement) than just concatenating a perfect secrecy cipher and an authentication code.