Transmission Distortion Research Articles

Robust Image Transmission Over Wireless Sensor Networks

Robust image and video communications have become more imperative due to the ubiquitous proliferation of multimedia applications over wireless sensor networks. In this work, the transmission distortions on the image data induced by both channel and instant node failures for Wireless Sensor Networks (WSN) are considered. The effect of two techniques and their integration with multipath transmission are investigated to compensate the multimedia distortions at the expense of incurring additional energy consumption and/or wasting bandwidth resources. First technique is watermarking based error concealment utilizing discrete wavelet transform for embedding downsized replicas of original image into itself. The other is conventional Reed---Solomon (RS) coding utilizing additional information bits to correct bit/symbol errors. Performance results obtained from extensive simulations utilizing a communication and energy model applicable to WSN show that error concealment (EC) integrated schemes, especially EC with multipath fusion (ECMF), are more promising to compensate losses than RS-coding-integrated and pure multipath transmission techniques in WSN.

An Approach to Security Using Rijndael Algorithm

ABSTRACT The existing system consisted of files with literally no file security. The main issue of Reading or tapping data is secrecy and confidentiality. Confidentiality has always played an important role in diplomatic and military matters. Often Information must be stored or transferred from one place to another without being exposed to an opponent or enemy. The main aim of presenting this paper is to encrypt a java file using Rijndael Algorithm. The first aspect that has to be considered in our paper is file security and the need for file security. Key management is also related to Confidentiality. This deals with generating, distributing and storing keys .File security must be implemented so as to eliminate the problems like unauthorized access, execution of commands illicitly, destructive behavior and confidentiality reaches. The values of Keywords Bytes, Cipher, state, finite field Addition, multiplication. 1. INTRODUCTION Standards like Rijndael was to be implemented due to the following factors against which several security measures had to be taken up like. Reading or tapping data, Manipulating and modifying data and Illegal use of files, Corrosion of data files, Distortion of data transmission and Disturbance of the operation of equipment or systems. Also Computer files and networks must be protected against intruders and Unauthorized. That includes File Security, Cryptography and Private-Key-Encryption, Key Management.

Prediction of transmission distortion for wireless video communication: Algorithm and application

In this paper, we develop algorithms for estimating transmission distortion in wireless video communication systems. By leveraging the analytical results obtained in our previous works, we design low complexity algorithms that are capable of estimating transmission distortion accurately. We also extend our algorithm for pixel-level transmission distortion estimation to pixel-level end-to-end distortion estimation. Furthermore, we apply our pixel-level end-to-end distortion estimation algorithm to prediction mode decision in H.264 encoder. Experimental results show that (1) our transmission distortion estimation algorithm is more accurate and more robust against inaccurate channel estimation than existing distortion estimation algorithms; (2) our mode decision algorithm achieves remarkable PSNR gain over the existing algorithms for prediction mode decision in H.264 encoder, e.g., an average PSNR gain of 1.44 dB for ‘foreman’ sequence when Packet Error Probability (PEP) equals 5%.

Association of IL-2RA/CD25 with type 1 diabetes in the Belgian population

Our goals were to study the proposed association of IL-2RA /CD25 with type 1 diabetes in the Belgian population over a broad age range, and to explore possible correlations with disease phenotypes, immune markers, HLA-DQ, INS, and PTPN22. Patients ( n = 1954), healthy controls ( n = 2082), and families ( n = 420) were genotyped for IL-2RA/CD25 rs41295061(C>A), HLA-DQ, INS-VNTR and PTPN22. IL-2RA/CD25 was associated with type 1 diabetes (χ 2 = 26.8, p < 0.001 for alleles and χ 2 = 29.6, p < 0.001 for genotypes). The C allele (odds ratios [OR] = 1.59) and C/C genotype (OR = 1.56) were identified as susceptibility variants, whereas the A allele (OR = 0.63), A/A genotype (OR = 0.14), and A/C genotype (OR = 0.69) as protective variants. IL-2RA/CD25 is associated with both early-onset and late-onset type 1 diabetes, but with a larger effect size in early-onset disease. There was a nonsignificant tendency toward transmission distortion ( p = 0.063). Except a tendency toward younger age at onset in carriers of the C/C genotype, no correlations with disease phenotype, immune markers, HLA-DQ, INS and PTPN22 were observed. Also, the frequency of the susceptible genotype was higher in early-onset compared with late-onset TID patients ( p = 0.015). In conclusion, IL-2RA/CD25 is associated with type 1 diabetes in the Belgian population, independently of disease phenotype and other biologic markers.

Comprehensive, Fine-Scale Dissection of Homologous Recombination Outcomes at a Hot Spot in Mouse Meiosis

In mammalian meiosis, only a small fraction of programmed DNA double-strand breaks are repaired as interhomolog crossovers (COs). To analyze another product of meiotic recombination, interhomolog noncrossovers (NCOs), we performed high-resolution mapping of recombination events at an intensely active mouse hot spot in F1 hybrids derived from inbred mouse strains. We provide direct evidence that the vast majority of repair events are interhomolog NCOs, consistent with models in which frequent interhomolog interactions promote accurate chromosome pairing. NCOs peaked at the center of the hot spot but were also broadly distributed throughout. In some hybrid strains, localized zones within the hot spot were highly refractory to COs and showed elevated frequency of coconversion of adjacent polymorphisms in NCOs, raising the possibility of double-strand gap repair. Transmission distortion was observed in one hybrid, with NCOs providing a significant contribution. Thus, NCO recombination events play a substantial role in mammalian meiosis and genome evolution.

Nonlinear Distortion in Transmission of Higher Order Modulation Formats

Transmission performance of a range of modulation formats including differentially encoded binary-, quaternary-, 8-, and 16-phase-shift-keying (DBPSK, DQPSK, D8PSK, and D16PSK) as well as 8- and 16-quadrature amplitude modulation (D8QAM and D16QAM) over optically compensated and DCF-free links are compared. Four different pulse-shapes are considered in a single-channel environment and the relative impact of intrachannel nonlinearities and nonlinear phase noise are analyzed.

A Multimedia Quality-Driven Network Resource Management Architecture for Wireless Sensor Networks With Stream Authentication

Media integrity, transmission quality, and energy efficiency are critical for secure wireless image streaming in a wireless multimedia sensor network (WMSN). However, conventional data authentication and resource allocation schemes cannot be applied directly to WMSN due to the constraints on limited energy and computing resources. In this paper, we propose a quality-driven scheme to optimize stream authentication and unequal error protection (UEP) jointly. This scheme can provide digital image authentication, image transmission quality optimization, and high energy efficiency for WMSN. The contribution of this research is two-fold as summarized below. First, a new resource allocation-aware greedy stream authentication approach is proposed to simplify the authentication process. Second, an authentication-aware wireless network resource allocation scheme is developed to reduce image distortion and energy consumption in transmission. The scheme is studied by unequally protected image packets with the consideration of coding and authentication dependency. Simulation results demonstrate that the proposed scheme achieves a performance gain of 3 ~ 5ndB in terms of authenticated image distortion.

Association of DRD2 variants and Gilles de la Tourette syndrome in a family-based sample from a South American population isolate

Gilles de la Tourette Syndrome (GTS) is a chronic neuropsychiatric disorder characterized by motor and vocal tics. Epidemiological evidence supports the importance of genetic factors in disease susceptibility, whereas pharmacological and neuroimaging studies have suggested a defect in the dopamine system. The dopamine receptor D2 gene (DRD2) has been reported to be associated with GTS and related phenotypes. Here, we evaluate genetic association between DRD2 and GTS in a sample from a South American population isolate (Antioquia, Colombia). We genotyped nine single nucleotide polymorphisms (SNPs) across the DRD2 gene region in 69 GTS patients and their nuclear families and carried out both SNP and haplotype-based transmission distortion analysis. Evidence for association was found for three SNPs (rs6279, rs1079597 and rs4648318) and a five marker-haplotype comprising both rs6279 and rs1079597. Our findings replicate the association of DRD2 and GTS, and are consistent with the proposed connection between the dopamine system and this complex neuropsychiatric disease.

Maternal angiotensinogen (AGT) haplotypes, fetal renin (REN) haplotypes and risk of preeclampsia; estimation of gene-gene interaction from family-triad data

BackgroundPreeclampsia is a debilitating disorder affecting approximately 3% of pregnant women in the Western world. Although inconclusive, current evidence suggests that the renin-angiotensin system may be involved in hypertension. Therefore, our objective was to determine whether the genes for placental renin (REN) and maternal angiotensinogen (AGT) interact to influence the risk of preeclampsia.MethodsThree haplotype-tagging SNPs (htSNPs) covering REN (rs5705, rs1464818, and rs3795575) and another three covering AGT (rs2148582, rs2478545 and rs943580) were genotyped in 99 mother-father-child triads of preeclampsia pregnancies. We estimated relative risks (RR) conferred by maternal AGT and fetal REN haplotypes using HAPLIN, a statistical software designed to detect multi-marker transmission distortion among triads. To assess a combined effect of maternal AGT and fetal REN haplotypes, the preeclamptic triads were first stratified by presence/absence of maternal AGT haplotype C-T-A and tested for an effect of fetal REN across these strata.ResultsWe found evidence that mothers carrying the most frequent AGT haplotype, C-T-A, had a reduced risk of preeclampsia (RR of 0.4, 95% CI = 0.2-0.8 for heterozygotes and 0.6, 95% CI = 0.2-1.5 for homozygotes). Mothers homozygous for AGT haplotypes t-c-g and C-c-g appeared to have a higher risk, but only the former was statistically significant. We found only weak evidence of an overall effect of fetal REN haplotypes and no support for our hypothesis that an effect of REN depended on whether the mother carried the C-T-A haplotype of AGT (p = 0.33).ConclusionOur findings indicate that the mother's AGT haplotypes affect her risk for developing preeclampsia. However, this risk is not influenced by fetal REN haplotypes.

FAM5C Contributes to Aggressive Periodontitis

Aggressive periodontitis is characterized by a rapid and severe periodontal destruction in young systemically healthy subjects. A greater prevalence is reported in Africans and African descendent groups than in Caucasians and Hispanics. We first fine mapped the interval 1q24.2 to 1q31.3 suggested as containing an aggressive periodontitis locus. Three hundred and eighty-nine subjects from 55 pedigrees were studied. Saliva samples were collected from all subjects, and DNA was extracted. Twenty-one single nucleotide polymorphisms were selected and analyzed by standard polymerase chain reaction using TaqMan chemistry. Non-parametric linkage and transmission distortion analyses were performed. Although linkage results were negative, statistically significant association between two markers, rs1935881 and rs1342913, in the FAM5C gene and aggressive periodontitis (p = 0.03) was found. Haplotype analysis showed an association between aggressive periodontitis and the haplotype A-G (rs1935881-rs1342913; p = 0.009). Sequence analysis of FAM5C coding regions did not disclose any mutations, but two variants in conserved intronic regions of FAM5C, rs57694932 and rs10494634, were found. However, these two variants are not associated with aggressive periodontitis. Secondly, we investigated the pattern of FAM5C expression in aggressive periodontitis lesions and its possible correlations with inflammatory/immunological factors and pathogens commonly associated with periodontal diseases. FAM5C mRNA expression was significantly higher in diseased versus healthy sites, and was found to be correlated to the IL-1β, IL-17A, IL-4 and RANKL mRNA levels. No correlations were found between FAM5C levels and the presence and load of red complex periodontopathogens or Aggregatibacter actinomycetemcomitans. This study provides evidence that FAM5C contributes to aggressive periodontitis.

Experimentally evaluated impact of nonlinear loads on the energy transmission losses and distortion of voltage waveforms

Experimentally evaluated impact of nonlinear loads on the energy transmission losses and distortion of voltage waveforms

Transmission distortion by loss of p21 or p27 cyclin-dependent kinase inhibitors following competitive spermatogonial transplantation

Spermatogonial stem cells (SSCs) undergo self-renewal division to support spermatogenesis. Although several positive regulators of SSC self-renewal have been identified, little is known about the mechanisms that negatively regulate SSCs. Here we developed a novel transplantation assay for SSCs and demonstrate that p21 and p27 cyclin-dependent kinase inhibitors play critical roles in SSC self-renewal and differentiation. Overexpression of p21 or p27 abrogated proliferation of cultured SSCs in vitro, and their expression levels were downregulated by exogenous self-renewal signals. In contrast, no apparent defects were found in p21 or p27-deficient SSCs by spermatogonial transplantation. However, competitive spermatogonial transplantation with WT SSCs revealed that the loss of either gene causes distortion of germline transmission: p21-deficiency facilitated mutant offspring production, whereas germline transmission was limited by p27-deficiency. Serial transplantation also showed that the loss of p27, but not p21, decreases secondary colony formation, suggesting that appropriate amounts of p27 are necessary for sustaining SSC self-renewal. Thus, p21 and p27 cyclin-dependent kinase inhibitors play critical roles in germline transmission by regulating the balance between SSC self-renewal and differentiation, and competitive spermatogonial transplantation technique will be useful for analyzing subtle defects in spermatogenesis that are not evident by traditional spermatogonial transplantation.

Experimental evaluation of neutron performance in boron-doped low activation concrete

Reaction rate distribution in concrete with/without boron dopant up to a thickness of 60 cm was measured using Yayoi fast reactor located at University of Tokyo. The 7 reaction rates such as (197)Au(n,gamma), (59)Co(n,gamma), (115)In(n,n'), (55)Mn(n,gamma), (23)Na(n,gamma), (94)Zr(n,gamma) and (96)Zr(n,gamma) were measured at 12 different depths, and the reduction of the reaction rate as a result of boron doping was quantitatively analysed. These reaction rates were also used to determine epithermal neutron spectrum shape parameter. Monte Carlo simulations of the experimental setup were performed using the MCNP-5 code. Simulated depth profiles of reaction rates and the epithermal neutron spectrum shape parameter agreed with the experimental results with fair accuracy. This experimental results provide useful data to benchmark the accuracy of neutron transport codes in the prediction of transmission and neutron spectrum distortion in boron-doped concrete.

Polymorphisms of the macrophage migration inhibitory factor gene in a UK population with Type 1 diabetes mellitus

Macrophage migration inhibitory factor (MIF) is a potent pro-inflammatory cytokine whose production is transcriptionally regulated by glucose. Experimental data from both Type 1 diabetes mellitus (T1D) patients and animal models suggests a role for MIF in the development of T1D. The aim of this study was to employ gene resequencing to identify common DNA polymorphisms in the MIF gene and subsequently assess haplotype tagged single nucleotide polymorphisms (htSNPs) using a combination of case-control and family-based association analyses in order to assess the association of MIF htSNPs with the development of T1D in a white population. All exons, introns and approximately 3 kb upstream and downstream of the MIF gene were screened for DNA polymorphisms in 46 individuals using DNA sequencing. Genotyping of the htSNPs was performed in 432 cases, 407 control subjects and 290 T1D parent-offspring trios, using Taqman, Sequenom, Pyrosequencing and fluorescence-based microsatellite technologies. Twenty-three polymorphisms (two novel) with a minor allele frequency > 10% were identified. Four MIF htSNPs (rs875643 G>A, rs7388067 C>T, rs5844572 -/CATT, rs6003941 T>G) were identified. Allele and haplotype frequencies were similar between case and control groups (P > 0.6 by permutation test) and assessment of allele transmission distortion from informative parents to affected offspring also failed to find an association. Stratification of these analyses for age-at-onset and human leukocyte antigen (HLA)-DR risk group (DR3/DR4) did not reveal any significant associations. It is unlikely that common polymorphisms in the MIF gene strongly influence susceptibility to T1D in the UK population.

Association Between Bone Morphogenetic Protein 4 Gene Polymorphisms with Nonsyndromic Cleft Lip with or without Cleft Palate in a Chilean Population

Nonsyndromic cleft lip with or without cleft palate (NSCLP) is one of the most common birth defects in humans with both genetic and environmental components involved in its expression. Experimental evidences have postulated that bone morphogenetic protein 4 gene (Bmp4) is involved in the etiology of cleft lip with or without cleft palate (CL/P) in mice. In our study we analyzed the association between BMP4 and NSCLP in a sample of 150 unrelated trios ascertained through affected probands. Three BMP4 polymorphisms were analyzed, two intronic (rs762642 and rs2855532) and rs1957860, located 5.7 kb upstream from BMP4. Transmission/disequilibrium tests were performed at the allele and haplotype levels. Our results did not detect preferential transmission for individual single-nucleotide polymorphisms. Significant transmission distortion was observed for haplotypes rs1957860-rs762642 (p = 0.018), especially for C-T (p = 0.015) and T-T (p = 0.018) which include the genomic region where the promoter and an enhancer of BMP4 are located. Thus, despite the positive association detected between these haplotypes and NSCLP they probably do not have a functional effect on BMP4 expression or protein activity but possibly reflect NSCLP susceptibility changes which are in linkage disequilibrium with these polymorphisms. The findings of our study support a role for BMP4 in NSCLP in the admixed Chilean population.

Fine-Granularity Transmission Distortion Modeling for Video Packet Scheduling Over Mesh Networks

Packet scheduling is a critical component in multi-session video streaming over mesh networks. Different video packets have different levels of contribution to the overall video presentation quality at the receiver side. In this work, we develop a fine-granularity transmission distortion model for the encoder to predict the quality degradation of decoded videos caused by lost video packets. Based on this packet-level transmission distortion model, we propose a content-and-deadline-aware scheduling (CDAS) scheme for multi-session video streaming over multi-hop mesh networks, where content priority, queuing delays, and dynamic network transmission conditions are jointly considered for each video packet. Our extensive experimental results demonstrate that the proposed transmission distortion model and the CDAS scheme significantly improve the performance of multi-session video streaming over mesh networks.

Improvement of DEA performance against harmonic distortion

This paper presents a filtering application to improve the behavior of the Differential Equation Algorithm (DEA) against harmonic distortion in transmission and distribution power systems. The proposed filter is based on Fast Fourier Transform (FFT) techniques during steady-state conditions. The voltage and current continuous-time equations are also considered, in fault conditions, to estimate the fundamental component waveforms of voltage and current. Simulations results show the singularities problems of DEA algorithm against harmonic distortion and the accurate operation achieved within 0.32 cycles using this filtering application.

Constructing an initial map of transmission distortion based on high density HapMap SNPs across the human autosomes

Transmission distortion (TD) is a significant departure from Mendelian predictions of genes or chromosomes to offspring. While many biological processes have been implicated, there is still much to be understood about TD in humans. Here we present our findings from a genome-wide scan for evidence of TD using haplotype data of 60 trio families from the International HapMap Project. Fisher's exact test was applied to assess the extent of TD in 629,958 SNPs across the autosomes. Based on the empirical distribution of P(Fisher) and further permutation tests, we identified 1,205 outlier loci and 224 candidate genes with TD. Using the PANTHER gene ontology database, we found 19 categories of biological processes with an enrichment of candidate genes. In particular, the "protein phosphorylation" category contained the largest number of candidates in both HapMap samples. Further analysis uncovered an intriguing non-synonymous change in PPP1R12B, a gene related to protein phosphorylation, which appears to influence the allele transmission from male parents in the YRI (Yoruba from Ibadan, Nigeria) population. Our findings also indicate an ethnicity-related property of TD signatures in HapMap samples and provide new clues for our understanding of TD in humans.

Compressed-Domain-Based Transmission Distortion Modeling for Precoded H.264/AVC Video

Transmission distortion analysis for video streams is a considerably challenging task. In this letter, a compressed-domain-based (CDB) transmission distortion model for precoded H.264/advanced video coding video streams is developed. Unlike the earlier schemes, which were based on pixel domain and required a complete decoding of the compressed video streams, the CDB model only requires some information on the video features, which can be directly extracted from the compressed video streams. Therefore, the complexity of the calculations is substantially reduced, which is well suited for real-time applications. More specifically, the model is applicable to the real-time transmission for precoded video streams, such as video on demand and mobile video. The experimental results demonstrate high accuracy of the model. Furthermore, an application example using the CDB model in resource allocation in real-time multiuser video communication reveals the applicability and effectiveness of the model.

Key-frame reference selection for non-feedback video communication

This article addresses the problem of reference picture optimization in video communication over error prone networks. A novel estimation model for transmission distortion is proposed. This model is capable of recursively estimating the overall end-to-end distortion caused by quantization, error propagation, and error concealment. Simulation results show that this model can accurately estimate channel distortion. Then, based on the distortion estimation model, a new non-feedback key-frame reference picture selection (KRPS) algorithm is developed. The optimum reference picture minimizes the transmission distortion under the rate-distortion optimization framework. Extensive experiment results demonstrate that the proposed KRPS algorithm substantially achieves more peak signal to noise ratio (PSNR) gain over traditional prediction, especially in low bit-rate transmission.