Production of titanium-dioxide nanomaterials (nano-TiO 2) is increasing, leading to potential ris... more Production of titanium-dioxide nanomaterials (nano-TiO 2) is increasing, leading to potential risks associated with unintended release of these materials into aquatic ecosystems. We investigated the acute effects of nano-TiO 2 on metabolic activity and viability of algae and cyanobacteria using high-throughput screening. The responses of three diatoms (Surirella angusta, Cocconeis placentula, Achnanthidium lanceolatum), one green alga (Scenedesmus quadricauda), and three cyanobacteria (Microcystis aeruginosa, Gloeocapsasp., Synechococcus cedrorum) to short-term exposure (15 to 60 min) to a common nano-TiO 2 pigment (PW6; average crystallite size 81.5 nm) with simulated solar illumination were assessed. Five concentrations of nano-TiO 2 (0.5, 2.5, 5, 10, and 25 mg L-1) were tested and a fluorescent reporter (fluorescein diacetate) was used to assess metabolic activity. Algae were sensitive to nano-TiO 2 , with all showing decreased metabolic activity after 30-min exposure to the lowest tested concentration. Microscopic observation of algae revealed increased abundance of dead cells with nano-TiO 2 exposure. Cyanobacteria were less sensitive to nano-TiO 2 than algae, with Gloeocapsashowing no significant decrease in activity with nano-TiO 2 exposure and Synechococcusshowing an increase in activity. These results suggest that nanomaterial contamination has the potential to alter the distribution of phototrophic microbial taxa within freshwater ecosystems. The higher resistance of cyanobacteria could have significant implications as cyanobacteria represent a less nutritious food source for higher trophic levels and some cyanobacteria can produce toxins and contribute to harmful algal blooms.
International Conference on Software Maintenance, 2002. Proceedings.
In this paper, we propose to use the static single assignment form, which was originally proposed... more In this paper, we propose to use the static single assignment form, which was originally proposed for code optimization in compilation techniques, in order to transform software components into a data-flow representation. Thus, hardware testability concepts can be used to analyze the testability of components that are described by C or Ada programs. Such a testability analysis helps designers during
IEEE Conference on Intelligent Transportation Systems, Proceedings, ITSC, 2007
This paper presents a lane detection system that combines stereovision-specific techniques with g... more This paper presents a lane detection system that combines stereovision-specific techniques with grayscale image processing for maximizing the robustness and applicability against the difficult conditions of the urban environment. The lane marking features are extracting using a fast and robust dark-light-dark transition detector that's aware of the perspective effect. The clothoid lane model is matched to the extracted features using line segment fitting for two distance intervals, under special constraints that ensure correctness. Freeform lane border detection, independent on the geometry constraints, driven by lane marking features only, is used to solve the situations not suited for clothoid representation. The results of each detection method are fused together in a Kalman filter based framework.
2007 IEEE Intelligent Transportation Systems Conference, 2007
A new approach for the detection of the road surface and obstacles is presented. The 3D data from... more A new approach for the detection of the road surface and obstacles is presented. The 3D data from dense stereo is transformed into a rectangular elevation map. A quadratic road surface model is first fitted, by a RANSAC approach, to the region in front of the ego vehicle. This primary solution is then refined by a region growing-like process, driven by the 3D resolution and uncertainty model of the stereo sensor. An optimal global solution for the road surface is obtained. The road surface is used for a rough discrimination between road and above-road points. Above-road points are grouped based on vicinity and false areas are rejected. Each above-road area is classified into obstacles (cars, pedestrians etc.) or traffic isles (road-parallel patches) by using criteria related to the density of the 3D points. The proposed real-time algorithm was evaluated in an urban scenario and can be used in complex applications, from ego-pose estimation to path planning. I. INTRODUCTION ROCESSING 3D data from stereo (dense or sparse) is a challenging task. A robust approach can prove of great value for a variety of applications in urban driving assistance. There are two main algorithm classes, depending on the space where processing is performed: disparity space-based and 3D space-based. Disparity space-based algorithms are more popular because they work directly on the result of stereo reconstruction: the disparity map. The "v-disparity" [1] approach is well known and used to detect the road surface in a variety of applications [2]. Unfortunately, it is not a natural way to represent 3D data and has some drawbacks: it assumes that the road should occupy most of the image, and it is sensitive to roll angle changes. If the roll angle of the ego car changes from the initial calibration, than the road profile becomes blurry and harder to detect on the "vdisparity" image. 3D space-based algorithms are mainly used for ego-pose estimation [3], [4], but also for lane and obstacle detection [5], [6].
Advanced driving assistance systems (ADAS) form a complex multidisciplinary research field, aimed... more Advanced driving assistance systems (ADAS) form a complex multidisciplinary research field, aimed at improving traffic efficiency and safety. A realistic analysis of the requirements and of the possibilities of the traffic environment leads to the establishment of several goals for traffic assistance, to be implemented in the near future (ADASE, INVENT, PREVENT, INTERSAFE) including: highway, rural and urban assistance, intersection management, pre-crash. While there are approaches to driving safety and efficiency that focus on the conditions exterior to the vehicle (intelligent infrastructure), it is reasonable to assume that we should expect the best results from the in-vehicle systems. Traditionally, vehicle safety is mainly defined by passive safety measures. Passive safety is achieved by a highly sophisticated design and construction of the vehicle body. The occupant cell has become a more rigid structure in order to mitigate deformations. The frontal part of vehicles has been improved as well, e.g. it incorporates specially designed "soft" areas to reduce the impact in case of a collision with a pedestrian. In the recent decades a lot of improvements have been done in this field. Similarly to the passive safety systems, primitive active safety systems, such as airbags, are only useful when the crash is actually happening, without much assessment of the situation, and sometimes they are acting against the well-being of the vehicle occupants. It has become clear that the future of the safety systems is in the realm of the artificial intelligence, systems that sense, decide and act. Sensing implies a continuous, fast and reliable estimation of the surroundings. The decision component takes into account the sensorial information and assesses the situation. For instance, a pre-crash application must decide whether the situation is of no danger, whether the crash is possible or when the crash is imminent, because depending on the situation different actions are required: warning, emergency braking or deployment of irreversible measures (internal airbags for passenger protection, or inflatable hood for pedestrian protection). While warning may be annoying, and applying the brakes potentially dangerous, deploying non-reversible safety causes permanent damage to the vehicle, and therefore the decision is not to be taken lightly. However, in a pre-crash scenario it is even more damaging if the protection systems fail to act. Therefore, it is paramount that the Open Access Database www.i-techonline.com
DNA transfer by particle bombardment makes use of physical processes to achieve the transformatio... more DNA transfer by particle bombardment makes use of physical processes to achieve the transformation of crop plants. There is no dependence on bacteria, so the limitations inherent in organisms such as Agrobacterium tumefaciens do not apply. The absence of biological constraints, at least until DNA has entered the plant cell, means that particle bombardment is a versatile and effective transformation method, not
Production of titanium-dioxide nanomaterials (nano-TiO 2) is increasing, leading to potential ris... more Production of titanium-dioxide nanomaterials (nano-TiO 2) is increasing, leading to potential risks associated with unintended release of these materials into aquatic ecosystems. We investigated the acute effects of nano-TiO 2 on metabolic activity and viability of algae and cyanobacteria using high-throughput screening. The responses of three diatoms (Surirella angusta, Cocconeis placentula, Achnanthidium lanceolatum), one green alga (Scenedesmus quadricauda), and three cyanobacteria (Microcystis aeruginosa, Gloeocapsasp., Synechococcus cedrorum) to short-term exposure (15 to 60 min) to a common nano-TiO 2 pigment (PW6; average crystallite size 81.5 nm) with simulated solar illumination were assessed. Five concentrations of nano-TiO 2 (0.5, 2.5, 5, 10, and 25 mg L-1) were tested and a fluorescent reporter (fluorescein diacetate) was used to assess metabolic activity. Algae were sensitive to nano-TiO 2 , with all showing decreased metabolic activity after 30-min exposure to the lowest tested concentration. Microscopic observation of algae revealed increased abundance of dead cells with nano-TiO 2 exposure. Cyanobacteria were less sensitive to nano-TiO 2 than algae, with Gloeocapsashowing no significant decrease in activity with nano-TiO 2 exposure and Synechococcusshowing an increase in activity. These results suggest that nanomaterial contamination has the potential to alter the distribution of phototrophic microbial taxa within freshwater ecosystems. The higher resistance of cyanobacteria could have significant implications as cyanobacteria represent a less nutritious food source for higher trophic levels and some cyanobacteria can produce toxins and contribute to harmful algal blooms.
International Conference on Software Maintenance, 2002. Proceedings.
In this paper, we propose to use the static single assignment form, which was originally proposed... more In this paper, we propose to use the static single assignment form, which was originally proposed for code optimization in compilation techniques, in order to transform software components into a data-flow representation. Thus, hardware testability concepts can be used to analyze the testability of components that are described by C or Ada programs. Such a testability analysis helps designers during
IEEE Conference on Intelligent Transportation Systems, Proceedings, ITSC, 2007
This paper presents a lane detection system that combines stereovision-specific techniques with g... more This paper presents a lane detection system that combines stereovision-specific techniques with grayscale image processing for maximizing the robustness and applicability against the difficult conditions of the urban environment. The lane marking features are extracting using a fast and robust dark-light-dark transition detector that's aware of the perspective effect. The clothoid lane model is matched to the extracted features using line segment fitting for two distance intervals, under special constraints that ensure correctness. Freeform lane border detection, independent on the geometry constraints, driven by lane marking features only, is used to solve the situations not suited for clothoid representation. The results of each detection method are fused together in a Kalman filter based framework.
2007 IEEE Intelligent Transportation Systems Conference, 2007
A new approach for the detection of the road surface and obstacles is presented. The 3D data from... more A new approach for the detection of the road surface and obstacles is presented. The 3D data from dense stereo is transformed into a rectangular elevation map. A quadratic road surface model is first fitted, by a RANSAC approach, to the region in front of the ego vehicle. This primary solution is then refined by a region growing-like process, driven by the 3D resolution and uncertainty model of the stereo sensor. An optimal global solution for the road surface is obtained. The road surface is used for a rough discrimination between road and above-road points. Above-road points are grouped based on vicinity and false areas are rejected. Each above-road area is classified into obstacles (cars, pedestrians etc.) or traffic isles (road-parallel patches) by using criteria related to the density of the 3D points. The proposed real-time algorithm was evaluated in an urban scenario and can be used in complex applications, from ego-pose estimation to path planning. I. INTRODUCTION ROCESSING 3D data from stereo (dense or sparse) is a challenging task. A robust approach can prove of great value for a variety of applications in urban driving assistance. There are two main algorithm classes, depending on the space where processing is performed: disparity space-based and 3D space-based. Disparity space-based algorithms are more popular because they work directly on the result of stereo reconstruction: the disparity map. The "v-disparity" [1] approach is well known and used to detect the road surface in a variety of applications [2]. Unfortunately, it is not a natural way to represent 3D data and has some drawbacks: it assumes that the road should occupy most of the image, and it is sensitive to roll angle changes. If the roll angle of the ego car changes from the initial calibration, than the road profile becomes blurry and harder to detect on the "vdisparity" image. 3D space-based algorithms are mainly used for ego-pose estimation [3], [4], but also for lane and obstacle detection [5], [6].
Advanced driving assistance systems (ADAS) form a complex multidisciplinary research field, aimed... more Advanced driving assistance systems (ADAS) form a complex multidisciplinary research field, aimed at improving traffic efficiency and safety. A realistic analysis of the requirements and of the possibilities of the traffic environment leads to the establishment of several goals for traffic assistance, to be implemented in the near future (ADASE, INVENT, PREVENT, INTERSAFE) including: highway, rural and urban assistance, intersection management, pre-crash. While there are approaches to driving safety and efficiency that focus on the conditions exterior to the vehicle (intelligent infrastructure), it is reasonable to assume that we should expect the best results from the in-vehicle systems. Traditionally, vehicle safety is mainly defined by passive safety measures. Passive safety is achieved by a highly sophisticated design and construction of the vehicle body. The occupant cell has become a more rigid structure in order to mitigate deformations. The frontal part of vehicles has been improved as well, e.g. it incorporates specially designed "soft" areas to reduce the impact in case of a collision with a pedestrian. In the recent decades a lot of improvements have been done in this field. Similarly to the passive safety systems, primitive active safety systems, such as airbags, are only useful when the crash is actually happening, without much assessment of the situation, and sometimes they are acting against the well-being of the vehicle occupants. It has become clear that the future of the safety systems is in the realm of the artificial intelligence, systems that sense, decide and act. Sensing implies a continuous, fast and reliable estimation of the surroundings. The decision component takes into account the sensorial information and assesses the situation. For instance, a pre-crash application must decide whether the situation is of no danger, whether the crash is possible or when the crash is imminent, because depending on the situation different actions are required: warning, emergency braking or deployment of irreversible measures (internal airbags for passenger protection, or inflatable hood for pedestrian protection). While warning may be annoying, and applying the brakes potentially dangerous, deploying non-reversible safety causes permanent damage to the vehicle, and therefore the decision is not to be taken lightly. However, in a pre-crash scenario it is even more damaging if the protection systems fail to act. Therefore, it is paramount that the Open Access Database www.i-techonline.com
DNA transfer by particle bombardment makes use of physical processes to achieve the transformatio... more DNA transfer by particle bombardment makes use of physical processes to achieve the transformation of crop plants. There is no dependence on bacteria, so the limitations inherent in organisms such as Agrobacterium tumefaciens do not apply. The absence of biological constraints, at least until DNA has entered the plant cell, means that particle bombardment is a versatile and effective transformation method, not
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