Detection Methods for Data-dependent Noise in Storage Channels

High density data storage systems suffer from the presence of data dependent noise during the read-back process. Detection methods such as the standard Viterbi algorithm (VA) are optimal se-quence detectors in the maximum likelihood (ML) sense for inter-symbol interference (ISI) channels when they are corrupted by stationary, additive white Gaussian noise (AWGN). Therefore a direct application of VA after a partial response (PR) equalizer in high density data storage read-channels results in performance loss due to the presence of data dependent (non-stationary) noise. In this paper, we will provide a tutorial of the concepts and tools necessary for performing optimal detection for ISI channels when the noise belongs to the more general class of data de-pendent, Gauss-Markov processes. We will employ these techniques to design both hard and soft decision detectors and study data dependent noise prediction detectors which make use of ML and maximum a posteriori (MAP) techniques in detail. We will also provide some numerical simulation results for these detection techniques when used for a longitudinal recording channel.

Feasibility study of immersive virtual prism adaptation therapy with depth-sensing camera using functional near-infrared spectroscopy in healthy adults

Prism Adaptation (PA) is used to alleviate spatial neglect. We combined immersive virtual reality with a depth-sensing camera to develop virtual prism adaptation therapy (VPAT), which block external visual cues and easily quantify and monitor errors than conventional PA. We conducted a feasibility study to investigate whether VPAT can induce behavioral adaptations by measuring after-effect and identifying which cortical areas were most significantly activated during VPAT using functional near-infrared spectroscopy (fNIRS). Fourteen healthy subjects participated in this study. The experiment consisted of four sequential phases (pre-VPAT, VPAT-10 degrees, VPAT-20 degrees, and post-VPAT). To compare the most significantly activated cortical areas during pointing in different phases against pointing during the pre-VPAT phase, we analyzed changes in oxyhemoglobin concentration using fNIRS during pointing. The pointing errors of the virtual hand deviated to the right-side during early pointing blocks in the VPAT-10 degrees and VPAT-20 degrees phases. There was a left-side deviation of the real hand to the target in the post-VPAT phase, demonstrating after-effect. The most significantly activated channels during pointing tasks were located in the right hemisphere, and possible corresponding cortical areas included the dorsolateral prefrontal cortex and frontal eye field. In conclusion, VPAT may induce behavioral adaptation with modulation of the dorsal attentional network.N

Optically pumped distributed feedback dye lasing with slide-coated TiO2 inverse-opal slab as Bragg reflector

We demonstrate an optical amplification of organic dye within a TiO2 inverse-opal (IO) distributed feedback (DFB) reflector prepared by a slide-coating method. Highly reflective TiO2 IO film was fabricated by slide coating the binary aqueous dispersions of polystyrene microspheres and charge-stabilized TiO2 nanoparticles on a glass slide and subsequently removing the polymer-opal template. TiO2 IO film was infiltrated, in turn, with the solutions of DCM, a fluorescent dye in various solvents with different indices of refraction. Optical pumping by frequency-doubled Nd: YAG laser resulted in amplified spontaneous emission in each dye solution. In accordance with the semi-empirical simulation by the FDTD method, DCM in ethanol showed the best emission/stopband matching for the TiO2 IO film used in this study. Therefore, photo excitation of a DCM/ethanol cavity showed a single-mode DFB lasing at 640 nm wavelength at moderate pump energy. (C) 2014 Optical Society of AmericaX1144sciescopu

p53 Codon 72 and p21 Codon 31 Polymorphisms and Susceptibility to Cervical Adenocarcinoma in Korean Women

The aims of this study were to evaluate the genotype frequencies of p53 codon 72 and p21 codon 31 in cervical adenocarcinoma patients and controls, and the association between the specific genotype or genotype combination of these polymorphisms and the risk of cervical adenocarcinoma in Korean women. Genotyping was performed using DNA from cervical biopsy specimens collected from 53 patients with cervical adenocarcinoma, of whom 34 were HPV 16 or 18 positive, and from the cervical exfoliated cells from 286 control women, of whom 48 were positive for HPV 16 or 18. For the determination of p53 polymorphisms genomic DNA was examined by PCR amplification of the specific allele assay, and for the determination of p21 polymorphisms DNA was examined by the PCR-RFLP assay using BsmA1. We found significant differences in genotype frequencies of both genes between the two groups (p < 0.001). The p53 genotypes containing the Pro allele were significantly associated with cervical adenocarcinoma with an OR of 2.89 (95% Cl 1.54-5.42). Also, homozygous carriers of the p21 Ser allele showed a substantially increased risk of developing cervical adenocarcinoma (OR 2.07; 95% Cl 1.13-3.79) compared to genotypes containing the Are allele. In addition, the combination of the Pro allele containing genotypes of p53 and the Ser homozygous genotype of p21 posed a remarkably increased risk (OR 5.22; 95% Cl 2.24-12.16), although the interaction of the two genes could not be found. These significant differences were intensified in groups with high-risk HPV infection (types 16 or 18).Shin HR, 2008, INT J CANCER, V122, P393, DOI 10.1002/ijc.23015Santos AM, 2006, EUR J CANCER, V42, P958, DOI 10.1016/j.ejca.2006.01.015Bhattacharya P, 2005, GYNECOL ONCOL, V99, P176, DOI 10.1016/j.ygyno.2005.06.007Li GJ, 2005, CARCINOGENESIS, V26, P1596, DOI 10.1093/carcin/bgi105Roh JW, 2004, GYNECOL ONCOL, V93, P499, DOI 10.1016/j.ygyno.2004.02.005Wu MT, 2004, CANCER LETT, V205, P61, DOI 10.1016/j.canlet.2003.11.026Koushik A, 2004, CANCER EPIDEM BIOMAR, V13, P11Helt AM, 2002, J VIROL, V76, P10559, DOI 10.1128/JVI.76.20.10559-10568.2002Powell BL, 2002, CARCINOGENESIS, V23, P311Lee EY, 2002, TOXICOL IND HEALTH, V18, P201, DOI 10.1191/0748233702th141oaAndersson S, 2001, BRIT J CANCER, V85, P1153Klug SJ, 2001, CANCER EPIDEM BIOMAR, V10, P1009Hildesheim A, 2001, BRIT J CANCER, V84, P1219, DOI 10.1054/bjoc.2001.1779Roh JW, 2001, CANCER LETT, V165, P59Harima Y, 2001, INT J MOL MED, V7, P261Kim JW, 2001, AM J OBSTET GYNECOL, V184, P55, DOI 10.1067/mob.2001.108329Yang YC, 2001, GYNECOL OBSTET INVES, V51, P197Shih CM, 2000, JPN J CANCER RES, V91, P9Tachezy R, 1999, HUM GENET, V105, P564Walboomers JMM, 1999, J PATHOL, V189, P12Zehbe I, 1999, LANCET, V354, P218KIM JW, 1999, J KOREAN CANC ASS, V31, P403Minaguchi T, 1998, CANCER RES, V58, P4585Storey A, 1998, NATURE, V393, P229Birgander R, 1996, HUM HERED, V46, P148ZAKUT R, 1995, ONCOGENE, V11, P393SUN Y, 1995, CANCER EPIDEM BIOMAR, V4, P261CHEDID M, 1994, ONCOGENE, V9, P3021ELDEIRY WS, 1993, CELL, V75, P817HOPKINS MP, 1991, OBSTET GYNECOL, V77, P912SCHEFFNER M, 1990, CELL, V63, P1129BRINTON LA, 1987, CANCER RES, V47, P1706