title: Separating true range measurements from multi-path and scattering interference in commercial range cameras

authors: Dorrington, Adrian A.

subjects: camera

abstract: Time-of-flight range cameras acquire a three-dimensional image of a scene simultaneously for all pixels from a single viewing location. Attempts to use range cameras for metrology applications have been hampered by the multi-path problem, which causes range distortions when stray light interferes with the range measurement in a given pixel. Correcting multi-path distortions by post-processing the three-dimensional measurement data has been investigated, but enjoys limited success because the interference is highly scene dependent. An alternative approach based on separating the strongest and weaker sources of light returned to each pixel, prior to range decoding, is more successful, but has only been demonstrated on custom built range cameras, and has not been suitable for general metrology applications. In this paper we demonstrate an algorithm applied to both the Mesa Imaging SR-4000 and Canesta Inc. XZ-422 Demonstrator unmodified off-the-shelf range cameras. Additional raw images are acquired and processed using an optimization approach, rather than relying on the processing provided by the manufacturer, to determine the individual component returns in each pixel. Substantial improvements in accuracy are observed, especially in the darker regions of the scene.

text: Separating true range measurements from multi-path and scattering interference in commercial range cameras Time-of-flight range cameras acquire a three-dimensional image of a scene simultaneously for all pixels from a single viewing location. Attempts to use range cameras for metrology applications have been hampered by the multi-path problem, which causes range distortions when stray light interferes with the range measurement in a given pixel. Correcting multi-path distortions by post-processing the three-dimensional measurement data has been investigated, but enjoys limited success because the interference is highly scene dependent. An alternative approach based on separating the strongest and weaker sources of light returned to each pixel, prior to range decoding, is more successful, but has only been demonstrated on custom built range cameras, and has not been suitable for general metrology applications. In this paper we demonstrate an algorithm applied to both the Mesa Imaging SR-4000 and Canesta Inc. XZ-422 Demonstrator unmodified off-the-shelf range cameras. Additional raw images are acquired and processed using an optimization approach, rather than relying on the processing provided by the manufacturer, to determine the individual component returns in each pixel. Substantial improvements in accuracy are observed, especially in the darker regions of the scene.

year: 2011

title: Impact of 3-Aminopropyltriethoxysilane-Coated Iron Oxide Nanoparticles on Menaquinone-7 Production Using B-subtilis

authors: Ranmadugala, Dinali Niluka Achala

subjects: Science & Technology

abstract: One of the major issues associated with industrial production of menaquinone-7 (MK–7) is the low fermentation yield. In this study, we investigated the effect of iron oxide nanoparticles coated with 3–aminopropyltriethoxysilane (IONs@APTES) on the production of MK–7 using B. subtilis (ATCC 6633). Decoration of B. subtilis cells with IONs@APTES significantly enhanced both MK–7 production and yield. An approximately two-fold increase in MK–7 production (41 mg/L) was observed in the presence of 500 µg/mL IONs@APTES, as compared to MK–7 production using untreated bacteria (22 mg/L). This paper, therefore, illustrates the immense biotechnological potential of IONs@APTES in increasing MK–7 concentration using B. subtilis, and its future role in bioprocess engineering.

text: Impact of 3-Aminopropyltriethoxysilane-Coated Iron Oxide Nanoparticles on Menaquinone-7 Production Using B-subtilis One of the major issues associated with industrial production of menaquinone-7 (MK–7) is the low fermentation yield. In this study, we investigated the effect of iron oxide nanoparticles coated with 3–aminopropyltriethoxysilane (IONs@APTES) on the production of MK–7 using B. subtilis (ATCC 6633). Decoration of B. subtilis cells with IONs@APTES significantly enhanced both MK–7 production and yield. An approximately two-fold increase in MK–7 production (41 mg/L) was observed in the presence of 500 µg/mL IONs@APTES, as compared to MK–7 production using untreated bacteria (22 mg/L). This paper, therefore, illustrates the immense biotechnological potential of IONs@APTES in increasing MK–7 concentration using B. subtilis, and its future role in bioprocess engineering.

year: 2017-11-01

title: Viewing restorative approaches to addressing challenging behaviour of minority ethnic students through a community of practice lens

authors: Wearmouth, Janice

subjects: restorative practice

abstract: The disproportionately high rates of school exclusion and lower levels of academic achievement of students from particular minority ethnic groups have been a focus of investigation in educational research across the world for some time. This articles uses a communities of practice framework to examine how restorative practice can draw on family and community values to support students whose behaviour is unacceptable in schools to recognize their own agency in behaving for good or ill and reintegrate them into the school community. At the same time, it acknowledges hurt that may be done to victims of wrong-doing and emphasizes putting things right between all those affected. The examples here are from Aotearoa New Zealand. They relate to practices influenced by traditional Māori cultural values. However, the principles and process associated with restorative practices that aim to restore harmony between the individual, the victim and the collective rather than to punish and exclude may be relevant within other student groups where high rates of exclusion from school are problematic.

text: Viewing restorative approaches to addressing challenging behaviour of minority ethnic students through a community of practice lens The disproportionately high rates of school exclusion and lower levels of academic achievement of students from particular minority ethnic groups have been a focus of investigation in educational research across the world for some time. This articles uses a communities of practice framework to examine how restorative practice can draw on family and community values to support students whose behaviour is unacceptable in schools to recognize their own agency in behaving for good or ill and reintegrate them into the school community. At the same time, it acknowledges hurt that may be done to victims of wrong-doing and emphasizes putting things right between all those affected. The examples here are from Aotearoa New Zealand. They relate to practices influenced by traditional Māori cultural values. However, the principles and process associated with restorative practices that aim to restore harmony between the individual, the victim and the collective rather than to punish and exclude may be relevant within other student groups where high rates of exclusion from school are problematic.

year: 2012