Purpose: To determine the prevalence of relative anterior microphthalmos (RAM) and evaluate intraoperative performance and surgical outcome in eyes with RAM undergoing cataract surgery. Design: Nested case-control ser...Purpose: To determine the prevalence of relative anterior microphthalmos (RAM) and evaluate intraoperative performance and surgical outcome in eyes with RAM undergoing cataract surgery. Design: Nested case-control series. Participants: One thousand four hundred consecutive patients undergoing cataract surgery were evaluated to determine the prevalence of RAM. Relative anterior microphthalmos is defined as horizontal corneal diameter (HCD) ≤ 11 mm, anterior chamber depth (ACD) ≤ 2.2 mm, and axial length (AL)>20 mm, with no other morphologic malformation. Methods: Patients were examined preoperatively for HCD, ACD, and AL. Horizontal corneal diameter was measured with calipers. Anterior chamber depth and AL were measured with immersion shell with water. Associated ocular pathologic conditionswere recorded. Two control groupswere identified. Group I (normal eyes; n=84) had HCD >11 mm, ACD >2.2 mm, and AL >20 mm. Group II (eyes with small corneal diameter; n=84) had HCD ≤ 11 mm, ACD >2.2 mm, and AL >20 mm. Main Outcome Measures: Patients with RAM and controls were evaluated for intraoperative performance and postoperative outcome. The 2- tailed Fisher exact test was applied to compare the performance of RAM with each of the control groups. The odds ratio (OR) with 95% confidence intervals (95% CI) was determined. Results: The prevalence of RAM was 6% (84 of 1400 eyes; 95% CI, 0.048- 0.074). Relative anterior microphthalmos was associated with the presence of small pupil, 34 (40.48% ); corneal guttae, 31(36.9% ); glaucoma, 29(34.5% ); and pseudoexfoliation, 6(7.14% ). Intraoperatively, RAM was associated with overall surgical difficulty because of less working space in 59 eyes (70.24% ; OR, 63.7; 95% CI, 18.3- 221; P < 0.001) compared with control groups I and II; uveal trauma in 12(14.28% ); Descemet’s detachment in 5 (5.95% ); and posterior capsule rupture in 2 (2.38% ). Postoperatively, RAM was associated with transient corneal edema in 63 eyes (75% ; OR, 9.0; 95% CI, 4.4- 18.0; P < 0.001; OR, 5.4; 95% CI, 2.7- 10.5; P < 0.001) on the first postoperative day. Conclusions: The prevalence of RAM was 6% . Relative anterior microphthalmos with its associations posed significant intraoperative difficulties. The occurrence of transient corneal edema was frequent.展开更多
Aim To detect sensor failure in control system using a single sensor signal. Methods A neural predictor was designed based on a radial basis function network(RBFN), and the neural predictor learned the sensor sig...Aim To detect sensor failure in control system using a single sensor signal. Methods A neural predictor was designed based on a radial basis function network(RBFN), and the neural predictor learned the sensor signal on line with a hybrid algorithm composed of n means clustering and Kalman filter and then gave the estimation of the sensor signal at the next step. If the difference between the estimation and the actural values of the sensor signal exceeded a threshold, the sensor could be declared to have a failure. The choice of the failure detection threshold depends on the noise variance and the possible prediction error of neural predictor. Results and Conclusion\ The computer simulation results show the proposed method can detect sensor failure correctly for a gyro in an automotive engine.展开更多
A nonlinear robust control strategy is proposed to force an underactuated surface ship to follow a predefined path with uncertain environmental disturbance and parameters.In the controller design,a high-gain observer ...A nonlinear robust control strategy is proposed to force an underactuated surface ship to follow a predefined path with uncertain environmental disturbance and parameters.In the controller design,a high-gain observer is used to estimate velocities,thus only position and yaw angle measurements are required.The control problem of underactuated system is transformed into a control of fully actuated system through adopting an improved line-of-sight(LOS) guidance law.A sliding-mode controller is designed to eliminate the yaw angle error,and provide the control system robustness.The control law is proved semi-globally exponentially stable(SGES) by applying Lyapunov stability theory,and numerical simulation using real data of a monohull ship illustrates the effectiveness and robustness of the proposed methodology.展开更多
In the present work, uranium concentrations were measured in twenty surface soil samples forselected regions in AI-Anbargovernorate using fission track etch technique, CR-39 track detector was used for registration of...In the present work, uranium concentrations were measured in twenty surface soil samples forselected regions in AI-Anbargovernorate using fission track etch technique, CR-39 track detector was used for registration of induced fission tracks. The results show that, the uranium concentrations ranged from 4.61 ppm, 56.93 Bq/kg （AL-Falluja AL-Jolan District） to 1.81 ppm 22.35 Bq/kg （Anah）with an average 3.42±0.79 ppm, 41.76±9.04 Bq/kg. The present results have shown that the uranium concentrations in the studied surface soil samples were less than the allowed limit 11.7 ppm recommended by UNSCEAR, 1993.展开更多
Thoron （Rn-220） is an invisible, odorless radioactive gas and nine times heavier than air. Purpose of project is to set up procedure to determine Rn-220 concentration which has been carried out in laboratory using S...Thoron （Rn-220） is an invisible, odorless radioactive gas and nine times heavier than air. Purpose of project is to set up procedure to determine Rn-220 concentration which has been carried out in laboratory using Solid State Nuclear Track Detector （SSNTD） based passive detector technique. In this study, technical procedure has been applied in Karlsruhe diffusion chamber and LR-115, Type II strippable （Kodak Pathe, France） detector. The results have investigated how LR-115 work for Rn-220 by using Monazite ore to simultaneously measure Rn-222 and Rn-220. To carry out experiment, Karlsruhe diffusion chamber is used to with and without Poly-Ethylene （PE） membrane. Karlsruhe diffusion chamber with PE membrane only detect Rn-222, without PE membrane detect total Rn-222 and Rn-220. Precision evaluation by duplicate measure at 8 cm detector-source distance with relative standard deviation is less than 2.54%. Testing technical procedure, detectors have been sent to National Institute of Radiological Science （NIRS） for Rn-220 calibration exposure. After detectors have been calibration exposure at NIRS, it carried out all the following steps of procedure which set up at laboratory in 1NST, Vietnam. Finally, calibration factor calculated is 0.21 （tracks-cm2/Bq·m3·h） and constructed curve between integrated Tn-220 concentration and tracks density with factor R2 = 0.975.展开更多
The aim of the study was to compare radon concentrations and effective dose equivalent in state hospitals inside the Erbil city having different periods of building. Effective doses were estimated in different floors ...The aim of the study was to compare radon concentrations and effective dose equivalent in state hospitals inside the Erbil city having different periods of building. Effective doses were estimated in different floors of the five selected hospitals by using the （CR-39） solid state nuclear track detectors with the guide of 1CRP Publication 66. The hanged dosimeters were left for about 60 days and after etching the radon concentration, annual effective dose and effective dose equivalents were calculated. Annual effective doses were estimated as 〈 1 mSv, so the results reveal the present concentrations to be below the standard values in the studied hospitals. Therefore, no healthy risks concerning the radon activities are existing in the hospital staff and patients in these hospitals.展开更多
The new measurement scheme of IP performance metrics is for the mobile network in heterogeneous wireless network environment. In the proposed scheme, when Mobile Nodes （MNs） inside the mobile network needs to under...The new measurement scheme of IP performance metrics is for the mobile network in heterogeneous wireless network environment. In the proposed scheme, when Mobile Nodes （MNs） inside the mobile network needs to understand the condition of multiple comrmunicatinn paths outside the mobile netwtrk, they can get IP performance metrics, such as delay, jitter, bandwidth, packet loss, etc., irrespective of the preserre or absence of measurement functionality. At the same time, the proposed scheme dees not require the MN to he involved in measuring IP performance metrice. The Multihomed Mobile Router （MMR） with heterogeneons wireless interfaces measures IP performance metrics on behalf of the MNs inside the mobile network. Then, MNs can get measured IP perfonmnce metries from the MMR using L3 messages. The proposed scheme can reduce burden and power consumption of MNs with limited resource and batty power since MNs don＇ t measure IP performance metrics directly. In addition, it can reduce considerably traffic overhead over wireless links on multiple measurement paths since signaling messages and injeeted testing traffic are reduced.展开更多
An understanding of the absorption of light is essential for efficient photovoltaic and photodetection applications with III-V nanowire arrays. Here, we correlate experiments with modeling and verify experimentally th...An understanding of the absorption of light is essential for efficient photovoltaic and photodetection applications with III-V nanowire arrays. Here, we correlate experiments with modeling and verify experimentally the predicted absorption of light in InP nanowire arrays for varying nanowire diameter and length. We find that 2,000 nm long nanowires in a pitch of 400 nm can absorb 94% of the incident light with energy above the band gap and, as a consequence, light which in a simple ray-optics description would be travelling between the nanowires can be efficiently absorbed by the nanowires. Our measurements demonstrate that the absorption for long nanowires is limited by insertion reflection losses when light is coupled from the air top-region into the array. These reflection losses can be reduced by introducing a smaller diameter to the nanowire-part closest to the air top-region. For nanowire arrays with such a nanowire morphology modulation, we find that the absorptance increases monotonously with increasing diameter of the rest of the nanowire.展开更多
文摘Purpose: To determine the prevalence of relative anterior microphthalmos (RAM) and evaluate intraoperative performance and surgical outcome in eyes with RAM undergoing cataract surgery. Design: Nested case-control series. Participants: One thousand four hundred consecutive patients undergoing cataract surgery were evaluated to determine the prevalence of RAM. Relative anterior microphthalmos is defined as horizontal corneal diameter (HCD) ≤ 11 mm, anterior chamber depth (ACD) ≤ 2.2 mm, and axial length (AL)>20 mm, with no other morphologic malformation. Methods: Patients were examined preoperatively for HCD, ACD, and AL. Horizontal corneal diameter was measured with calipers. Anterior chamber depth and AL were measured with immersion shell with water. Associated ocular pathologic conditionswere recorded. Two control groupswere identified. Group I (normal eyes; n=84) had HCD >11 mm, ACD >2.2 mm, and AL >20 mm. Group II (eyes with small corneal diameter; n=84) had HCD ≤ 11 mm, ACD >2.2 mm, and AL >20 mm. Main Outcome Measures: Patients with RAM and controls were evaluated for intraoperative performance and postoperative outcome. The 2- tailed Fisher exact test was applied to compare the performance of RAM with each of the control groups. The odds ratio (OR) with 95% confidence intervals (95% CI) was determined. Results: The prevalence of RAM was 6% (84 of 1400 eyes; 95% CI, 0.048- 0.074). Relative anterior microphthalmos was associated with the presence of small pupil, 34 (40.48% ); corneal guttae, 31(36.9% ); glaucoma, 29(34.5% ); and pseudoexfoliation, 6(7.14% ). Intraoperatively, RAM was associated with overall surgical difficulty because of less working space in 59 eyes (70.24% ; OR, 63.7; 95% CI, 18.3- 221; P < 0.001) compared with control groups I and II; uveal trauma in 12(14.28% ); Descemet’s detachment in 5 (5.95% ); and posterior capsule rupture in 2 (2.38% ). Postoperatively, RAM was associated with transient corneal edema in 63 eyes (75% ; OR, 9.0; 95% CI, 4.4- 18.0; P < 0.001; OR, 5.4; 95% CI, 2.7- 10.5; P < 0.001) on the first postoperative day. Conclusions: The prevalence of RAM was 6% . Relative anterior microphthalmos with its associations posed significant intraoperative difficulties. The occurrence of transient corneal edema was frequent.
文摘Aim To detect sensor failure in control system using a single sensor signal. Methods A neural predictor was designed based on a radial basis function network(RBFN), and the neural predictor learned the sensor signal on line with a hybrid algorithm composed of n means clustering and Kalman filter and then gave the estimation of the sensor signal at the next step. If the difference between the estimation and the actural values of the sensor signal exceeded a threshold, the sensor could be declared to have a failure. The choice of the failure detection threshold depends on the noise variance and the possible prediction error of neural predictor. Results and Conclusion\ The computer simulation results show the proposed method can detect sensor failure correctly for a gyro in an automotive engine.
基金Projects(61004008,51509055)supported by the National Natural Science Foundation of ChinaProject(61422230302162223013)supported by the Laboratory of Science and Technology on Water Jet Propulsion,China
文摘A nonlinear robust control strategy is proposed to force an underactuated surface ship to follow a predefined path with uncertain environmental disturbance and parameters.In the controller design,a high-gain observer is used to estimate velocities,thus only position and yaw angle measurements are required.The control problem of underactuated system is transformed into a control of fully actuated system through adopting an improved line-of-sight(LOS) guidance law.A sliding-mode controller is designed to eliminate the yaw angle error,and provide the control system robustness.The control law is proved semi-globally exponentially stable(SGES) by applying Lyapunov stability theory,and numerical simulation using real data of a monohull ship illustrates the effectiveness and robustness of the proposed methodology.
文摘In the present work, uranium concentrations were measured in twenty surface soil samples forselected regions in AI-Anbargovernorate using fission track etch technique, CR-39 track detector was used for registration of induced fission tracks. The results show that, the uranium concentrations ranged from 4.61 ppm, 56.93 Bq/kg （AL-Falluja AL-Jolan District） to 1.81 ppm 22.35 Bq/kg （Anah）with an average 3.42±0.79 ppm, 41.76±9.04 Bq/kg. The present results have shown that the uranium concentrations in the studied surface soil samples were less than the allowed limit 11.7 ppm recommended by UNSCEAR, 1993.
文摘Thoron （Rn-220） is an invisible, odorless radioactive gas and nine times heavier than air. Purpose of project is to set up procedure to determine Rn-220 concentration which has been carried out in laboratory using Solid State Nuclear Track Detector （SSNTD） based passive detector technique. In this study, technical procedure has been applied in Karlsruhe diffusion chamber and LR-115, Type II strippable （Kodak Pathe, France） detector. The results have investigated how LR-115 work for Rn-220 by using Monazite ore to simultaneously measure Rn-222 and Rn-220. To carry out experiment, Karlsruhe diffusion chamber is used to with and without Poly-Ethylene （PE） membrane. Karlsruhe diffusion chamber with PE membrane only detect Rn-222, without PE membrane detect total Rn-222 and Rn-220. Precision evaluation by duplicate measure at 8 cm detector-source distance with relative standard deviation is less than 2.54%. Testing technical procedure, detectors have been sent to National Institute of Radiological Science （NIRS） for Rn-220 calibration exposure. After detectors have been calibration exposure at NIRS, it carried out all the following steps of procedure which set up at laboratory in 1NST, Vietnam. Finally, calibration factor calculated is 0.21 （tracks-cm2/Bq·m3·h） and constructed curve between integrated Tn-220 concentration and tracks density with factor R2 = 0.975.
文摘The aim of the study was to compare radon concentrations and effective dose equivalent in state hospitals inside the Erbil city having different periods of building. Effective doses were estimated in different floors of the five selected hospitals by using the （CR-39） solid state nuclear track detectors with the guide of 1CRP Publication 66. The hanged dosimeters were left for about 60 days and after etching the radon concentration, annual effective dose and effective dose equivalents were calculated. Annual effective doses were estimated as 〈 1 mSv, so the results reveal the present concentrations to be below the standard values in the studied hospitals. Therefore, no healthy risks concerning the radon activities are existing in the hospital staff and patients in these hospitals.
文摘The new measurement scheme of IP performance metrics is for the mobile network in heterogeneous wireless network environment. In the proposed scheme, when Mobile Nodes （MNs） inside the mobile network needs to understand the condition of multiple comrmunicatinn paths outside the mobile netwtrk, they can get IP performance metrics, such as delay, jitter, bandwidth, packet loss, etc., irrespective of the preserre or absence of measurement functionality. At the same time, the proposed scheme dees not require the MN to he involved in measuring IP performance metrice. The Multihomed Mobile Router （MMR） with heterogeneons wireless interfaces measures IP performance metrics on behalf of the MNs inside the mobile network. Then, MNs can get measured IP perfonmnce metries from the MMR using L3 messages. The proposed scheme can reduce burden and power consumption of MNs with limited resource and batty power since MNs don＇ t measure IP performance metrics directly. In addition, it can reduce considerably traffic overhead over wireless links on multiple measurement paths since signaling messages and injeeted testing traffic are reduced.
文摘An understanding of the absorption of light is essential for efficient photovoltaic and photodetection applications with III-V nanowire arrays. Here, we correlate experiments with modeling and verify experimentally the predicted absorption of light in InP nanowire arrays for varying nanowire diameter and length. We find that 2,000 nm long nanowires in a pitch of 400 nm can absorb 94% of the incident light with energy above the band gap and, as a consequence, light which in a simple ray-optics description would be travelling between the nanowires can be efficiently absorbed by the nanowires. Our measurements demonstrate that the absorption for long nanowires is limited by insertion reflection losses when light is coupled from the air top-region into the array. These reflection losses can be reduced by introducing a smaller diameter to the nanowire-part closest to the air top-region. For nanowire arrays with such a nanowire morphology modulation, we find that the absorptance increases monotonously with increasing diameter of the rest of the nanowire.
