The Experts below are selected from a list of 7905 Experts worldwide ranked by ideXlab platform
Y. Berger - One of the best experts on this subject based on the ideXlab platform.
-
Trellis-oriented decomposition and trellis complexity of composite-length cyclic codes
IEEE Transactions on Information Theory, 1995Co-Authors: Y. BergerAbstract:The trellis complexity of composite-length cyclic codes (CLCC's) is addressed. We first investigate the trellis properties of concatenated and product codes in general. Known factoring of CLCC's into concatenated subcodes is thereby employed to derive upper bounds on the minimal trellis size and state-space profile. New decomposition of CLCC's into product subcodes is established and utilized to derive further upper Hounds on the trellis parameters. The coordinate permutations that correspond to these bounds are exhibited. Additionally, new results on the generalized Hamming weights of CLCC's are obtained. The reduction in trellis complexity of many CLCC's leads to soft-decision decoders with relatively low complexity. >
Holger A. Volk - One of the best experts on this subject based on the ideXlab platform.
-
Cervical vertebral stenosis associated with a vertebral arch anomaly in the Basset Hound.
Journal of veterinary internal medicine, 2012Co-Authors: S. De Decker, L. De Risio, Mark Lowrie, Daniela Mauler, Elsa Beltran, A A Giedja, Patrick J. Kenny, Ingrid Gielen, Laurent Garosi, Holger A. VolkAbstract:Objectives To report the clinical presentation, imaging characteristics, treatment results, and histopathological findings of a previously undescribed vertebral malformation in the Basset Hound. Animals and Methods Retrospective case series study. Eighteen Basset Hounds presented for evaluation of a suspected cervical spinal cord problem. All dogs underwent computed tomography myelography or magnetic resonance imaging of the cervical region. Results Thirteen male and 5 female Basset Hounds between 6 months and 10.8 years of age (median: 1.4 years) were studied. Clinical signs varied from cervical hyperesthesia to nonambulatory tetraparesis. Imaging demonstrated a well-defined and smooth hypertrophy of the dorsal lamina and spinous process of ≥2 adjacent vertebrae. Although this bony abnormality could decrease the ventrodorsal vertebral canal diameter, dorsal midline spinal cord compression was predominantly caused by ligamentum flavum hypertrophy. The articulation between C4 and C5 was most commonly affected. Three dogs were lost to follow-up, 10 dogs underwent dorsal laminectomy, and medical management was initiated in 5 dogs. Surgery resulted in a good outcome with short hospitalization times (median: 4.5 days) in all dogs, whereas medical management produced more variable results. Histopathology confirmed ligamentum flavum hypertrophy and demonstrated the fibrocartilaginous nature of this anomaly. Conclusions and Clinical Importance Dorsal lamina and spinous process hypertrophy leading to ligamentum flavum hypertrophy should be included in the differential diagnosis of Basset Hounds with cervical hyperesthesia or myelopathy. Prognosis after decompressive surgery is favorable. Although a genetic component is suspected, additional studies are needed to determine the specific etiology of this disorder.
David H. Lloyd - One of the best experts on this subject based on the ideXlab platform.
-
Patch test responses to Malassezia pachydermatis in healthy basset Hounds and in basset Hounds with Malassezia dermatitis
Medical mycology, 2006Co-Authors: Ross Bond, Janet C. Patterson-kane, Natalie Perrins, David H. LloydAbstract:The effects of the patch test application of Malassezia pachydermatis extracts were evaluated in seven healthy basset Hounds and in seven basset Hounds with Malassezia dermatitis. Antigens (4 and 0.4 mg/ml) and saline controls were applied for 48 h using filter paper discs in Finn chambers. One healthy basset hound and five affected Hounds showed positive patch test reactivity to the yeast antigens. Positive patch test reactions were characterized histologically by mild epidermal hyperplasia and mild to moderate perivascular, periadnexal and interstitial infiltrates of neutrophils and CD3+ lymphocytes. Immediate intradermal test reactivity to M. pachydermatis antigens was seen in one healthy and one affected hound, whereas delayed intradermal test reactivity was seen in six healthy Hounds and five affected Hounds. This study indicates that patch test reactivity to M. pachydermatis antigen may occur in healthy basset Hounds, and in contrast to delayed intradermal test reactivity, is more frequent in basset Hounds with Malassezia dermatitis.
Terrie M. Williams - One of the best experts on this subject based on the ideXlab platform.
-
Energetics and evasion dynamics of large predators and prey: pumas vs. Hounds.
PeerJ, 2017Co-Authors: Caleb M. Bryce, Christopher C. Wilmers, Terrie M. WilliamsAbstract:Quantification of fine-scale movement, performance, and energetics of hunting by large carnivores is critical for understanding the physiological underpinnings of trophic interactions. This is particularly challenging for wide-ranging terrestrial canid and felid predators, which can each affect ecosystem structure through distinct hunting modes. To compare free-ranging pursuit and escape performance from group-hunting and solitary predators in unprecedented detail, we calibrated and deployed accelerometer-GPS collars during predator-prey chase sequences using packs of hound dogs (Canis lupus familiaris, 26 kg, n = 4–5 per chase) pursuing simultaneously instrumented solitary pumas (Puma concolor, 60 kg, n = 2). We then reconstructed chase paths, speed and turning angle profiles, and energy demands for Hounds and pumas to examine performance and physiological constraints associated with cursorial and cryptic hunting modes, respectively. Interaction dynamics revealed how pumas successfully utilized terrain (e.g., fleeing up steep, wooded hillsides) as well as evasive maneuvers (e.g., jumping into trees, running in figure-8 patterns) to increase their escape distance from the overall faster Hounds (avg. 2.3× faster). These adaptive strategies were essential to evasion in light of the mean 1.6× higher mass-specific energetic costs of the chase for pumas compared to Hounds (mean: 0.76 vs. 1.29 kJ kg−1 min−1, respectively). On an instantaneous basis, escapes were more costly for pumas, requiring exercise at ≥90% of predicted V ˙O2MAX and consuming as much energy per minute as approximately 5 min of active hunting. Our results demonstrate the marked investment of energy for evasion by a large, solitary carnivore and the advantage of dynamic maneuvers to postpone being overtaken by group-hunting canids.
Sébastien Gerchinovitz - One of the best experts on this subject based on the ideXlab platform.
-
Uniform regret bounds over $R^d$ for the sequential linear regression problem with the square loss
Proceedings of Machine Learning Research, 2019Co-Authors: Pierre Gaillard, Sébastien Gerchinovitz, Malo Huard, Gilles StoltzAbstract:We consider the setting of online linear regression for arbitrary deterministic sequences, with the square loss. We are interested in the aim set by Bartlett et al. (2015): obtain regret bounds that hold uniformly over all competitor vectors. When the feature sequence is known at the beginning of the game, they provided closed-form regret bounds of 2d B^2 ln T + O(1), where T is the number of rounds and B is a bound on the observations. Instead, we derive bounds with an optimal constant of 1 in front of the d B^2 ln T term. In the case of sequentially revealed features, we also derive an asymptotic regret bound of d B^2 ln T for any individual sequence of features and bounded observations. All our algorithms are variants of the online non-linear ridge regression forecaster, either with a data-dependent regularization or with almost no regularization.
-
Sparsity regret bounds for individual sequences in online linear regression
Journal of Machine Learning Research, 2011Co-Authors: Sébastien GerchinovitzAbstract:We consider the problem of online linear regression on arbitrary deterministic sequences when the ambient dimension d can be much larger than the number of time rounds T. We introduce the notion of sparsity regret bound, which is a deterministic online counterpart of recent risk bounds derived in the stochastic setting under a sparsity scenario. We prove such regret bounds for an online-learning algorithm called SeqSEW and based on exponential weighting and data-driven truncation. In a second part we apply a parameter-free version of this algorithm to the stochastic setting (regression model with random design). This yields risk bounds of the same flavor as in Dalalyan and Tsybakov (2011) but which solve two questions left open therein. In particular our risk bounds are adaptive (up to a logarithmic factor) to the unknown variance of the noise if the latter is Gaussian. We also address the regression model with fixed design.