Design and realization of random measurement scheme for compressed sensing （CS） are presented in this paper, and lower limits of the measurement number are achieved when the precise reconstruction is realized. Four ...Design and realization of random measurement scheme for compressed sensing （CS） are presented in this paper, and lower limits of the measurement number are achieved when the precise reconstruction is realized. Four kinds of random measurement matrices are designed according to the constraint conditions of random measurement. The performance is tested employing the algorithm of stagewise orthogonal matching pursuit （STOMP）. Results of the experiment show that lower limits of the measurement number are much better than the results described in Refs.[ 13-15]. When the ratios of measurement to sparsity are 3.8 and 4.0, the mean relative errors of the reconstructed signals are 8.57 × 10^-13 and 2.43 × 10^-14, respectively, which confh-rns that the random measurement scheme of this paper is very effective.展开更多
Purpose: To estimate the random measurement error in visual acuity (VA) determ ination in the clinical environment in cataractous, pseudophakic and healthy eye s. Methods: The VAs of patients referred for cataract sur...Purpose: To estimate the random measurement error in visual acuity (VA) determ ination in the clinical environment in cataractous, pseudophakic and healthy eye s. Methods: The VAs of patients referred for cataract surgery or consultation by ophthalmic professionals were re-examined and the VA results for distance usin g projector acuity charts were compared. Refractive errors were also remeasured. A total of 99 eyes (41 cataractous, 36 pseudophakic and 22 healthy eyes) were e xamined. The healthy comparison group consisted of hospital staff. Only one eye of each person and eyes with Snellen VAs of 0.3-1.3 (logMAR 0.52 to-0.11) were included. The mean time interval between the first and second examinations was 45 days. Results: The estimated standard deviation of measurement error (SDME) o f repeated VA measurements of all eyes was logMAR 0.06. Eyes with the lowest VA (0.3-0.45) had the largest variability (SDME logMAR 0.09), and eyes with VA ≥0 .7 had the smallest (SDME logMAR 0.04). The variability may be partly explained by the line size progression in lower VAs, partly by the difference in the remea surement of the refractive error. The difference in the average VA between exami nations 1 and 2 (logMAR 0.15 versus 0.12) was considered to be of some interest because it indicates that some learning effect is possible. Conclusion: Visual a cuity results in clinical settings have a certain degree of inherent variability . In this series variability ranged from SDME logMAR 0.04 (eyes with good vision ) to logMAR 0.09 (in the lower vision group) in the Snellen VA range of 0.3-1.3 . Changes should be judged with caution, especially in cases of decreased VA.展开更多
Let D be a convolution semigroup of random measures or point processes on a locally compact second countable T 2space. There is a topological isomorphism from D into a subsemigroup of product topological semigroup (R ...Let D be a convolution semigroup of random measures or point processes on a locally compact second countable T 2space. There is a topological isomorphism from D into a subsemigroup of product topological semigroup (R +,+) N.D is a sequentially stable and D-separable ZH-semigroup, as well as a metrizable, stable and normable Hun semigroup, so it has the corresponding properties. In particular the author has a new and simple proof byZH-semigroup approach or Hun semigroup approach to show that D has property ILID (an infinitesimal array limit is infinitely divisible), and know the Baire types which some subsets of D belong in.展开更多
基金supported by the National Natural Science Foundation of China(Nos.61072111 and 60672156)the Project of Science and Technology Commission of Jilin Province(Nos.20100503 and 20110360)
文摘Design and realization of random measurement scheme for compressed sensing （CS） are presented in this paper, and lower limits of the measurement number are achieved when the precise reconstruction is realized. Four kinds of random measurement matrices are designed according to the constraint conditions of random measurement. The performance is tested employing the algorithm of stagewise orthogonal matching pursuit （STOMP）. Results of the experiment show that lower limits of the measurement number are much better than the results described in Refs.[ 13-15]. When the ratios of measurement to sparsity are 3.8 and 4.0, the mean relative errors of the reconstructed signals are 8.57 × 10^-13 and 2.43 × 10^-14, respectively, which confh-rns that the random measurement scheme of this paper is very effective.
文摘Purpose: To estimate the random measurement error in visual acuity (VA) determ ination in the clinical environment in cataractous, pseudophakic and healthy eye s. Methods: The VAs of patients referred for cataract surgery or consultation by ophthalmic professionals were re-examined and the VA results for distance usin g projector acuity charts were compared. Refractive errors were also remeasured. A total of 99 eyes (41 cataractous, 36 pseudophakic and 22 healthy eyes) were e xamined. The healthy comparison group consisted of hospital staff. Only one eye of each person and eyes with Snellen VAs of 0.3-1.3 (logMAR 0.52 to-0.11) were included. The mean time interval between the first and second examinations was 45 days. Results: The estimated standard deviation of measurement error (SDME) o f repeated VA measurements of all eyes was logMAR 0.06. Eyes with the lowest VA (0.3-0.45) had the largest variability (SDME logMAR 0.09), and eyes with VA ≥0 .7 had the smallest (SDME logMAR 0.04). The variability may be partly explained by the line size progression in lower VAs, partly by the difference in the remea surement of the refractive error. The difference in the average VA between exami nations 1 and 2 (logMAR 0.15 versus 0.12) was considered to be of some interest because it indicates that some learning effect is possible. Conclusion: Visual a cuity results in clinical settings have a certain degree of inherent variability . In this series variability ranged from SDME logMAR 0.04 (eyes with good vision ) to logMAR 0.09 (in the lower vision group) in the Snellen VA range of 0.3-1.3 . Changes should be judged with caution, especially in cases of decreased VA.
文摘Let D be a convolution semigroup of random measures or point processes on a locally compact second countable T 2space. There is a topological isomorphism from D into a subsemigroup of product topological semigroup (R +,+) N.D is a sequentially stable and D-separable ZH-semigroup, as well as a metrizable, stable and normable Hun semigroup, so it has the corresponding properties. In particular the author has a new and simple proof byZH-semigroup approach or Hun semigroup approach to show that D has property ILID (an infinitesimal array limit is infinitely divisible), and know the Baire types which some subsets of D belong in.
