Multi-interval line coding (MILC) is considered with higher-order signalling. A simple recursive method to calculate the maximum number of valid MILC waveforms for any order of signalling is presented. Following the i...
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Multi-interval line coding (MILC) is considered with higher-order signalling. A simple recursive method to calculate the maximum number of valid MILC waveforms for any order of signalling is presented. Following the introduced recursive method, attractive higher-order MILC schemes are found. Properties of 3-ary and 4-ary MILC schemes are listed. MILC schemes that can increase the data rate by 25-40% over known PAM signals are reported.
We demonstrate that optical encryption methods based on the joint transform correlator architecture are vulnerable to chosen-plaintext attack. An unauthorized user, who introduces three chosen plaintexts in the access...
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We demonstrate that optical encryption methods based on the joint transform correlator architecture are vulnerable to chosen-plaintext attack. An unauthorized user, who introduces three chosen plaintexts in the accessible encryption machine, can obtain the security key code mask. In this contribution, we also propose an alternative method to eliminate ambiguities that allows obtaining the right decrypting key. (C) 2010 Elsevier B.V. All rights reserved.
A novel sequency-ordered discrete Hartley transform (SO-DHT) of an arbitrary length is proposed by introducing a systematic ordering of the rows of the DHT matrix, so that the resulting transform matrix has the sign c...
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A novel sequency-ordered discrete Hartley transform (SO-DHT) of an arbitrary length is proposed by introducing a systematic ordering of the rows of the DHT matrix, so that the resulting transform matrix has the sign changes of its entries similar to that of the discrete cosine transform (DCT) matrix. The experiments carried out show that the shape of the spectrum of the new SO-DHT is very similar to that of the DCT, especially from the point of view of energy compaction.
This work describes an algorithm for absorbed dose evaluation in the region of X-ray diagnostic energy based on the response of CaSO4:Dy thermoluminescence powder detectors. The absorbed dose was calculated using Mont...
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This work describes an algorithm for absorbed dose evaluation in the region of X-ray diagnostic energy based on the response of CaSO4:Dy thermoluminescence powder detectors. The absorbed dose was calculated using Monte Carlo simulation code (MCSC) and then compared to the experimental TLD results for X-rays effective energies Co-60 gamma radiation. In order to study the photon interaction in the matter, a cylindrical model of 1 cm(3) was used. The gamma radiation source was placed at 100 cm to the object: the source is considered as an isotropic source of Co-60. The energy deposited into the cylindrical model was determined by the Monte Carlo N-particle (MCNPX) method. Measurements of the TL phosphors were obtained by irradiating the powder by gamma radiation. TL glow curve of CaSO4:Dy after gamma irradiated at a 1 Gy of absorbed dose was then obtained. (C) 2009 Elsevier Ltd. All rights reserved.
In this reported work, differential detection to eavesdrop the encoded information in the temporal phase coding code-shift-keying OCDMA system, is proposed and experimentally demonstrated. Differential detection can b...
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In this reported work, differential detection to eavesdrop the encoded information in the temporal phase coding code-shift-keying OCDMA system, is proposed and experimentally demonstrated. Differential detection can be used to distinguish the discrepancy in the two encoded signals.
We show that the codebook of every general transmission system can also be regarded as a classical code in a natural way. Consequently, using the Hamming metric, bounds on the cardinality of the codebooks of transmiss...
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We show that the codebook of every general transmission system can also be regarded as a classical code in a natural way. Consequently, using the Hamming metric, bounds on the cardinality of the codebooks of transmission systems can be obtained directly from classical coding theory.
Let F be a finite field. A multiset S of integers is projection-forcing if for every linear function phi : F(n) -> F(m) whose multiset of weight changes is S, phi is a coordinate projection up to permutation and sc...
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Let F be a finite field. A multiset S of integers is projection-forcing if for every linear function phi : F(n) -> F(m) whose multiset of weight changes is S, phi is a coordinate projection up to permutation and scaling of entries. The MacWilliams Extension Theorem from coding theory says that S = (0, 0, ... , 0) is projection-forcing. We give a (super-polynomial) algorithm to determine whether or not a given S is projection-forcing. We also give a condition that can be checked in polynomial time that implies that S is projection-forcing. This result is a generalization of the MacWilliams Extension Theorem and work by the first author. (C) 2010 Elsevier Inc. All rights reserved.
New inner and outer bounds on the achievable compression-equivocation rate region for generalised secure data compression with side information are given that do not match in general. In this setup, two senders, Alice...
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New inner and outer bounds on the achievable compression-equivocation rate region for generalised secure data compression with side information are given that do not match in general. In this setup, two senders, Alice and Charlie intend to transmit information to Bob via channels with limited capacity so that he can reliably reconstruct their observations. The eavesdropper, Eve, has access to one of the channels at each instant and is interested in the source of the same channel at the time. Bob and Eve also have their own observations, which are correlated with Alice's and Charlie's observations. In this model, two equivocation and compression rates are defined with respect to the sources of Alice and Charlie. Furthermore, different special cases are discussed where the inner and outer bounds match. Our model covers the previously obtained results as well.
Multimedia applications are ubiquitous in daily life. To satisfy multiple requests equipped with different devices and bandwidths, scalable video coding has been developed. However, it is difficult to realise spatial ...
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Multimedia applications are ubiquitous in daily life. To satisfy multiple requests equipped with different devices and bandwidths, scalable video coding has been developed. However, it is difficult to realise spatial and quality scalabilities in practice owing to the increased coding complexity brought by inter-layer prediction. A novel fast mode decision algorithm for spatial scalable video coding is proposed in which macroblock modes in the base layer and the enhancement layer are predicted from each other. The experimental results show that the proposed algorithm provides up to 74% of time saving with ignorable quality degradation and acceptable bit rate increase.
Recent studies have suggested that the location of tactile stimuli is automatically recoded from anatomical into external coordinates, independent of the task requirements. However, research has mainly involved the tw...
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Recent studies have suggested that the location of tactile stimuli is automatically recoded from anatomical into external coordinates, independent of the task requirements. However, research has mainly involved the two hands, which may not be representative for the whole body because they are excessively used for the visually guided manipulation of objects and tools. We recorded event-related potentials (ERPs) while participants received tactile stimuli to the hands and feet, but attended only one limb. The hands were placed near the feet either in an uncrossed or a crossed posture, thus varying the spatial distance of each hand from each foot. Centro-parietal ERPs 100-140 msec poststimulus were more positive when stimulating the anatomically same-side hand while attending a foot. They were also more positive when the Euclidean distance between the stimulated hand and the attended foot was small rather than large. When a foot was stimulated and a hand attended, a similar modulation of foot ERPs was observed for the right foot. To assess the spatial distance between two limbs in space, the external location of both must be known. The present ERP results therefore suggest that not only the hands but also other body parts are remapped into external coordinates. The use of both anatomical and external coordinates may facilitate the control of actions toward tactile events and the choice of the most suitable effector.
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