Background:To compare femtosecond laser-assisted versus conventional phacoemulsification in terms of visual and refractive outcomes,cumulative dissipated energy,anterior chamber inflammation and endothelial cell loss....Background:To compare femtosecond laser-assisted versus conventional phacoemulsification in terms of visual and refractive outcomes,cumulative dissipated energy,anterior chamber inflammation and endothelial cell loss.Methods:In this retrospective cohort study,records of eyes that underwent femtosecond laser-assisted cataract surgery(FLACS)or conventional phacoemulsification(CP)were reviewed.The Victus femtosecond laser(Bausch and Lomb,Germany)was used to carry out corneal incisions,anterior capsulotomy,and lens fragmentation in FLACS procedures.Manifest refraction spherical equivalence(MRSE),uncorrected distance visual acuity(UDVA),corrected distance visual acuity(CDVA),cumulative dissipated energy(CDE),postoperative cells and flare and endothelial cell count data were collected.Subgroup analysis of the visual acuity tests was performed based on the type of intraocular lens implanted(monofocal,monofocal toric,multifocal,multifocal toric,accommodating).Results:A total of 735 eyes were included in the study(296 eyes for the FLACS group and 439 eyes for the CP group).At one year follow-up,120 eyes comprised the FLACS group and 265 eyes for the CP group.MRSE in the FLACS group was−0.16±0.58 D and−0.20±0.52 D in the CP group(P=0.50).UDVA in the FLACS group was 20/25(mean logMAR 0.12±0.13)and 20/25(mean logMAR 0.11±0.13)in the CP group(P=0.48).CDVA was 20/20(mean logMAR 0.03±0.07)in the FLACS group and 20/20(mean logMAR 0.02±0.06)in the CP group(P=0.15).No statistically significant trend was seen for FLACS versus CP by intraocular type for visual acuity.CDE for the different cataract grades ranged from 6.97±5.74 to 29.02±16.07 in the FLACS group and 7.59±6.42 to 35.69±18.30 in the CP group.The FLACS group was significantly lower for post-operative central corneal edema(P=0.05),cells and flare(P=0.01),and endothelial cell loss(P=0.04).Conclusions:Femtosecond laser-assisted cataract surgery and conventional phacoemulsification had similar refractive and visual outcomes.Phacoemulsification energy,anterior ch展开更多
More attention has been paid to the cost of intensive but sporadic floods than the cost of extensive but frequent events.To examine the impacts of intensive versus extensive events,we investigated the loss structure o...More attention has been paid to the cost of intensive but sporadic floods than the cost of extensive but frequent events.To examine the impacts of intensive versus extensive events,we investigated the loss structure of global flood-induced mortality by using the cumulative loss ratio,marginal benefit chart,and cumulative loss plot.Drawing on the flood-induced mortality data for four decades(1976–2016)from the international disaster database EM-DAT,we defined the levels of flood loss according to the frequency of flood-induced deaths,and calculated the cumulative mortality and the marginal benefits of flood loss prevention practices at different levels.Our analysis showed that for the world’s leading 30 countries with large flood-induced mortality and different levels of development:(1)70%of them have the cumulative deaths from extensive floods exceeding half of those caused by intensive floods in the study’s four data decades;and(2)80%of them tend to gain less marginal benefit with increasing levels of flood prevention,with their marginal benefits peaking at loss prevention levels of 2-year or 5-year flood-induced mortality.These results indicate that,in the long run,the cumulative deaths of extensive floods are comparable to that of intensive events,and prevention of loss from extensive events can be an efficient way to reduce the total loss.For flood risk management under conditions of climate change,extensive loss events deserve more consideration.展开更多
This paper presents a powerful approach to find the optimal size and location of distributed generation units in a distribution system using GA （Genetic Optimization algorithm）. It is proved that GA method is fast a...This paper presents a powerful approach to find the optimal size and location of distributed generation units in a distribution system using GA （Genetic Optimization algorithm）. It is proved that GA method is fast and easy tool to enable the planners to select accurate and the optimum size of generators to improve the system voltage profile in addition to reduce the active and reactive power loss. GA fitness function is introduced including the active power losses, reactive power losses and the cumulative voltage deviation variables with selecting weight of each variable. GA fitness function is subjected to voltage constraints, active and reactive power losses constraints and DG size constraint.展开更多
Banking institutions all over the world face significant challenge due to the cumulative loss due to defaults of borrowers of different types of loans. The cumulative default loss built up over a period of time could ...Banking institutions all over the world face significant challenge due to the cumulative loss due to defaults of borrowers of different types of loans. The cumulative default loss built up over a period of time could wipe out the capital cushion of the banks. The aim of this paper is to help the banks to forecast the cumulative loss and its volatility. Defaulting amounts are random and defaults occur at random instants of time. A non Markovian time dependent random point process is used to model the cumulative loss. The expected loss and volatility are evaluated analytically. They are functions of probability of default, probability of loss amount, recovery rate and time. Probability of default being the important contributor is evaluated using Hidden Markov modeling. Numerical results obtained validate the model.展开更多
文摘Background:To compare femtosecond laser-assisted versus conventional phacoemulsification in terms of visual and refractive outcomes,cumulative dissipated energy,anterior chamber inflammation and endothelial cell loss.Methods:In this retrospective cohort study,records of eyes that underwent femtosecond laser-assisted cataract surgery(FLACS)or conventional phacoemulsification(CP)were reviewed.The Victus femtosecond laser(Bausch and Lomb,Germany)was used to carry out corneal incisions,anterior capsulotomy,and lens fragmentation in FLACS procedures.Manifest refraction spherical equivalence(MRSE),uncorrected distance visual acuity(UDVA),corrected distance visual acuity(CDVA),cumulative dissipated energy(CDE),postoperative cells and flare and endothelial cell count data were collected.Subgroup analysis of the visual acuity tests was performed based on the type of intraocular lens implanted(monofocal,monofocal toric,multifocal,multifocal toric,accommodating).Results:A total of 735 eyes were included in the study(296 eyes for the FLACS group and 439 eyes for the CP group).At one year follow-up,120 eyes comprised the FLACS group and 265 eyes for the CP group.MRSE in the FLACS group was−0.16±0.58 D and−0.20±0.52 D in the CP group(P=0.50).UDVA in the FLACS group was 20/25(mean logMAR 0.12±0.13)and 20/25(mean logMAR 0.11±0.13)in the CP group(P=0.48).CDVA was 20/20(mean logMAR 0.03±0.07)in the FLACS group and 20/20(mean logMAR 0.02±0.06)in the CP group(P=0.15).No statistically significant trend was seen for FLACS versus CP by intraocular type for visual acuity.CDE for the different cataract grades ranged from 6.97±5.74 to 29.02±16.07 in the FLACS group and 7.59±6.42 to 35.69±18.30 in the CP group.The FLACS group was significantly lower for post-operative central corneal edema(P=0.05),cells and flare(P=0.01),and endothelial cell loss(P=0.04).Conclusions:Femtosecond laser-assisted cataract surgery and conventional phacoemulsification had similar refractive and visual outcomes.Phacoemulsification energy,anterior ch
基金partial financial support provided by the projects of the National Key Research and Development Program(Grant No.2016YFA0602404 and 2017YFA0604903)National Science Foundation of China(Grant No.41501020)partial financial support provided by the Science and Technology Planning Project of Guangdong Province,China(Grant No.2017B020244002 and 2019A070716007)。
文摘More attention has been paid to the cost of intensive but sporadic floods than the cost of extensive but frequent events.To examine the impacts of intensive versus extensive events,we investigated the loss structure of global flood-induced mortality by using the cumulative loss ratio,marginal benefit chart,and cumulative loss plot.Drawing on the flood-induced mortality data for four decades(1976–2016)from the international disaster database EM-DAT,we defined the levels of flood loss according to the frequency of flood-induced deaths,and calculated the cumulative mortality and the marginal benefits of flood loss prevention practices at different levels.Our analysis showed that for the world’s leading 30 countries with large flood-induced mortality and different levels of development:(1)70%of them have the cumulative deaths from extensive floods exceeding half of those caused by intensive floods in the study’s four data decades;and(2)80%of them tend to gain less marginal benefit with increasing levels of flood prevention,with their marginal benefits peaking at loss prevention levels of 2-year or 5-year flood-induced mortality.These results indicate that,in the long run,the cumulative deaths of extensive floods are comparable to that of intensive events,and prevention of loss from extensive events can be an efficient way to reduce the total loss.For flood risk management under conditions of climate change,extensive loss events deserve more consideration.
文摘This paper presents a powerful approach to find the optimal size and location of distributed generation units in a distribution system using GA （Genetic Optimization algorithm）. It is proved that GA method is fast and easy tool to enable the planners to select accurate and the optimum size of generators to improve the system voltage profile in addition to reduce the active and reactive power loss. GA fitness function is introduced including the active power losses, reactive power losses and the cumulative voltage deviation variables with selecting weight of each variable. GA fitness function is subjected to voltage constraints, active and reactive power losses constraints and DG size constraint.
文摘Banking institutions all over the world face significant challenge due to the cumulative loss due to defaults of borrowers of different types of loans. The cumulative default loss built up over a period of time could wipe out the capital cushion of the banks. The aim of this paper is to help the banks to forecast the cumulative loss and its volatility. Defaulting amounts are random and defaults occur at random instants of time. A non Markovian time dependent random point process is used to model the cumulative loss. The expected loss and volatility are evaluated analytically. They are functions of probability of default, probability of loss amount, recovery rate and time. Probability of default being the important contributor is evaluated using Hidden Markov modeling. Numerical results obtained validate the model.
