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Purpose: To evaluate the structural, microvascular, and functional progression of normal tension glaucoma (NTG) with or without high myopia by examining longitudinal changes in optical coherence tomography angiography (OCTA) and visual field (VF) parameters. Methods: We evaluated 61 NTG eyes and classified 25 of the eyes with axial lengths (ALs) of ≥26 mm as highly myopic. We assessed the rate of change in OCTA parameters, namely radial peripapillary capillary (RPC) vessel density (VD), parafovea VD, deep parafovea VD, retinal nerve fibre layer (RNFL) thickness, and ganglion cell complex thickness. We evaluated the correlation of the rate of change in OCTA parameters with VF loss and AL. Results: Among the 61 NTG eyes, rates of loss of RPC VD, parafovea VD, deep parafovea VD, and RNFL thickness were significantly different from zero despite the nonsignificant rate of change in VF mean deviation (MD). Changes in these OCTA parameters did not differ significantly in highly myopic NTG eyes. The rate of change in VF MD was significantly correlated with the rate of change in parafovea VD in highly myopic and non‐highly myopic NTG eyes. In highly myopic NTG eyes, AL was negatively correlated with the rates of loss of RNFL thickness, VF MD, and VF PSD. Conclusion: NTG eyes with a relatively stable VF exhibited loss of VD and RNFL thickness. VF progression in NTG was correlated with decreasing parafovea VD, indicating a structure–function correlation. Greater AL may indicate faster VF loss and RNFL thinning in highly myopic NTG eyes. [ABSTRACT FROM AUTHOR]

This prospective study aimed to explore the effect of medical intraocular pressure (IOP) reduction on structural and capillary vessel density (VD) change by optical coherence tomography (OCT) angiography in early glaucoma. Patients with newly diagnosed glaucoma and a follow-up of ≥6 months were enrolled. An ocular examination that included slit-lamp bio-microscopy, pneumatic tonometry, gonioscopy, standard automated perimetry, and OCT angiography was performed. Quantitative OCT angiography parameters were assessed using a linear mixed model that was adjusted for inter-eye correlation. The correlations between IOP changes and OCT angiography parameter changes were analyzed using Spearman's correlation test. In total, 52 eyes of 36 participants, including 33 glaucoma eyes of 17 participants and 19 healthy eyes of 19 participants served as the case and control groups, respectively. The IOP of the case group decreased from a baseline mean of 20.4 ± 0.8 mmHg to 15.7 ± 0.5 mmHg at 3 months (p < 0.001) and to 16.1 ± 0.5 mmHg at 6 months (p < 0.001). For the subgroup with an IOP reduction of >20%, the deep macula VD was negatively correlated with baseline IOP and significantly decreased at 3 months follow-up. Additionally, change in retinal nerve fiber layer (RNFL) was positively correlated with a change in IOP at 6 months. In conclusion, the deep-layer macula VD was correlated with baseline IOP and influenced by the reduction in IOP in the short term. The changes in VD revealed the vulnerability of the deep vascular complex. The OCTA parameters provide in vivo monitoring information during medical treatment for early glaucoma. [ABSTRACT FROM AUTHOR]

This retrospective cross-sectional study, which enrolled 124 normal tension glaucoma (NTG) eyes and 68 healthy eyes as the control, determined the association between central corneal thickness (CCT) and ocular parameters in NTG. CCT was measured using the Pentacam® system, optical coherence tomography angiography (OCT-A) was adopted to measure the peripapillary and macular area VDs, and spatial data were based on the Garway–Heath map as illustrated in OCT-A. Univariate and multivariate linear regressions were used to statistically analyze for associations between CCT and other factors. In this study, the mean age was similar for both the NTG and control groups. The mean CCT of the NTG group was significantly thinner than that of the control group (533.97 ± 33.11 µm vs. 546.78 ± 38.21 µm; p =.022). Considering all the factors, CCT negatively correlated with visual field (VF) pattern standard deviation (univariate, p =.045). To analyze structural and functional factors separately, we found a significant positive correlation between CCT and whole disc radial peripapillary capillary VD (VDRPC; multivariate, p =.019). To analyze the relationship between all factors and sectoral changes in VDRPC, a significant positive correlation was observed between CCT and inferior temporal VDRPC (univariate, p =.039) and inferior nasal VDRPC (VDRPC IN; univariate, p =.048). In conclusion, this novel study shows that among NTG participants, a thinner cornea correlated with weaker biomechanical properties susceptible to optic nerve tissue displacement, especially in response to mild transient elevation of IOP, leads to compromised ocular microcirculation. [ABSTRACT FROM AUTHOR]

Purpose: To characterize changes in the retinal nerve fiber layer (RNFL) and peripapillary vessel density (VD) at the site of disc hemorrhage (DH) in nonglaucomatous eyes. Materials and methods: This retrospective cross-sectional study included nonglaucomatous eyes diagnosed with unilateral DH. The change of DH was recorded using disc photography. Both anatomical data and functional visual field (VF) data were collected using optical coherence tomography angiography and Humphrey VF examination. Results: Sixteen patients were included with average follow-up duration of 95 months. Almost half of DH episodes was initially presented at the inferotemporal area of the optic disc. Pigment formation at the previous DH site after resolution was noted in 12.5% of eyes. Sectoral radial peripapillary VD at the DH site was significantly lower in DH eyes than in the control group; however, the sectoral RNFL thickness at the DH site was not significantly decreased. Progression of the VF defect corresponding to the DH site was found in 81.3% of eyes despite regular use of antiglaucoma agents. The mean change in the VF mean deviation was –0.64 dB/year in DH eyes. Conclusion: During long follow-up periods, decreased peripapillary VD at the DH site and progression of the VF defect corresponding to the DH site were detected in nonglaucomatous eyes. Retinal pigmentation with an RNFL defect is a clue for DH, although RNFL showed no significant change. Antiglaucoma treatment may not prevent the deterioration of visual function. [ABSTRACT FROM AUTHOR]

This article presents a computational model for the optimum design of an urban inter-modal public transit network. A software tool based on this model was developed to provide useful reference for transport planners in carrying out service planning, routing, and scheduling for an inter-modal transit network. The development of this model is briefly described here. A numerical example is used to illustrate its implementation. Results of sensitivity analyses demonstrate that it is capable of providing reasonable solutions and is responsive to changes in the planning environment. [ABSTRACT FROM AUTHOR]

Many studies have focused mainly on the development of a single automatic incident detection algorithm to detect incident occurrences, and the performance obtained has often been mixed. In this study, an algorithm fusion method was developed using incident data collected from the Central Expressway in Singapore. This method explores the possibility of enhancing incident detection performance by combining the complementary advantages of a group of existing algorithms. It was found that the fused algorithm with the following options has outperformed the existing algorithms: Fusion Option II—selecting a combination of the best-performing algorithms, and Fusion Option III—applying different weightings to a group of algorithms. Compared with the existing dual variable/combined detector evaluation algorithms developed earlier for the same studied site, the fused algorithms performed significantly better, with false alarm rates between 0.2 and 1.0%. At a detection rate of 90%, these fused algorithms were able to reduce the false alarm rate by more than 55%. This algorithm fusion method had yielded promising performance and thus can serve as an alternative technique to the commonly practiced approach of either developing a new algorithm or applying the existing algorithms to detect expressway incident occurrences. [ABSTRACT FROM AUTHOR]

Most automatic incident detection algorithms were successfully developed using loop-detector-based traffic measurements collected from their own localities. But their detection performances were not satisfactory when applied on data collected using a video-based detector system. The video-based detector system is gaining popularity as it was reported to be cost-effective, less prone to damage compared to loop detectors embedded in road pavement, and possesses surveillance capability. It is able to provide the homogeneity of traffic measurements with greater reliability in non-incident situations. In this study, a simple detection rule was used to develop algorithms that use video-based data for detecting lane-blocking incidents. A set of 96 incidents from Singapore's Central Expressway was used for calibrating these algorithms, with another 64 incidents for validation. Two single-station algorithms, named dual-variable (DV) and flow-based DV algorithms were developed. They have similar detection logic, but the latter includes a pre-incident traffic flow condition in its detection framework. On average, the flow-based DV algorithm outperformed the DV algorithm, and both proved to be effective techniques when compared to some existing loop-detector-based algorithms. [ABSTRACT FROM AUTHOR]

In heavy traffic flow conditions, vehicles have limited manouverability which affects the magnitude of response to incident-induced traffic disturbances and how fast changes in these traffic variables can signal the occurrence of an incident. Such characteristics are usually used to formulate a loop-based algorithm. A recent study reported that some existing algorithms were not able to maintain a desired level of effectiveness when these algorithms were used to detect incidents with a video-based detector system. Two new video-based automatic incident detection algorithms, the INdividual Detection Evaluation (INDE) and COmbined Detection Evaluation (CODE) algorithms were, therefore, developed for the detection of lane-blocking incidents in heavy traffic flow conditions using the Central Expressway in Singapore as a case study. The algorithms detect incident-induced traffic speed and occupancy disturbances differently: INDE processes information at each individual detector station and CODE processes information at two adjacent detector stations. Both algorithms outperformed existing algorithms commonly used in incident management systems. Of these algorithms, the INDE algorithm raised fewer false alarms and gave slightly faster incident warnings. However, its performance was relatively less consistent when applied to a validation database. [ABSTRACT FROM AUTHOR]

This study investigates the performance of several existing automatic incident detection algorithms along the Central Expressway in Singapore and freeways in Melbourne, Australia. These algorithms were originally developed for freeways in the United States. Thus, it is of interest to evaluate how they would perform when applied to cities in other countries. The evaluation is carried out on two databases containing 160 and 100 incidents collected from Singapore and Melbourne, respectively. These databases reflect differences in vehicle detector system used to collect traffic parameters and in driver behavior. The following empirical findings were obtained: (1) the Minnesota and Standard Normal Deviate (SND) algorithms appear to possess transferable properties as well as being able to receive wide-area traffic measurements from a machine-vision vehicle detector system; (2) California Algorithm number 7 and the Double Exponential Smoothing algorithm performed poorly in Singapore but may be transferable to Melbourne freeways; and (3) no significant difference in average efficiencies between the better-performing algorithms (SND and Minnesota) on both databases. [ABSTRACT FROM AUTHOR]

Fouling species produce adhesive polymers during the settlement, adhesion and colonization of new surfaces in the marine environment. The present paper tests the hypothesis that enzymes of the appropriate specificity may prevent biofouling by hydrolysing these adhesive polymers. Seventeen commercially available enzyme preparations designed originally for bulk use in a range of end-use applications were tested for their effects on the settlement and/or adhesion of three major fouling species, viz. the green alga Ulva linza , the diatom Navicula perminuta and the barnacle Balanus amphitrite . The serine-proteases were found to have the broadest antifouling potential reducing the adhesion strength of spores and sporelings of U. linza , cells of N. perminuta and inhibiting settlement of cypris larvae of B. amphitrite . Mode-of-action studies on the serine-protease, Alcalase, indicated that this enzyme reduced adhesion of U. linza in a concentration-dependent manner, that spores of the species could recover their adhesive strength if the enzyme was removed and that the adhesive of U. linza and juvenile cement of B. amphitrite became progressively less sensitive to hydrolysis as they cured. [ABSTRACT FROM AUTHOR]

Sea space planning and congestion management is receiving more attention. However, little work on sea space capacity and strategy analyses can be found in the literature. Compared to other transportation systems, a sea space system has some special features that require consideration. The system capacity also depends on the pattern of traffic using the system. In this paper, we model a sea space as a directional network and capacity models for berthing areas, anchorage areas, fairways and their intersections, as well as the entire sea space system are developed. These models can be used to compute capacity for any given traffic pattern which can be extracted from vessel trip records or from traffic forecasts. To implement these models, a software system called Sea Space Capacity and Strategy Analysis System (SCSAS) has been developed in Visual C + + and is now being used in Singapore. [ABSTRACT FROM PUBLISHER]

Energy costs and availability are major concerns in most parts of the world. Various measures to reduce energy consumption have been proposed. This paper focuses on two strategies to control aircraft ground operations as fuel conservation measures: operating fewer engines while taxiing, and towing aircraft between terminal area and runways. The potential benefits, costs, safety and operational issues related to implementation are investigated. As an illustration, the implementation of these strategies at ten major US airports is analyzed. About 278 million liters of jet fuel could potentially be saved from aircraft towing at these airports at their 1987 operation levels. However, there are some concerns related to towing which would make implementation unlikely until there is more urgency in fuel conservation. A more readily implementable strategy would be operating fewer engines while taxiing. About 88 million liters of fuel could potentially be conserved at these airports at 1987 operation levels. [ABSTRACT FROM PUBLISHER]

The movement of aircraft in the terminal airspace is simulated using a fast‐time, critical events model. The model tracks the flight of each aircraft within the airspace studied and estimates aircraft delays within the terminal airspace. It also provides other relevant statistics such as controller workload, flow rates and travel times. The airspace model is capable of simulating a multi‐airport, multi‐sector environment. It incorporates logic that minics controller coordination and anticipation, and includes consideration of conflict resolution, aircraft speed control, overtake situation, aircraft holding and dynamic runway assignment. Operational data collected in the field were used in a model evaluation exercise. Results indicated that the model is capable of simulating real‐world aircraft operations in the terminal airspace. [ABSTRACT FROM PUBLISHER]