Allan E. K. Lim

Robust Video/Ultrasonic Fusion-Based Estimation for Automotive Applications

In this paper, we use recently developed robust estimation ideas to improve object tracking by a stationary or nonstationary camera. Large uncertainties are always present in vision-based systems, particularly, in relation to the estimation of the initial state as well as the measurement of object motion. The robustness of these systems can be significantly improved by employing a robust extended Kalman filter (REKF). The system performance can also be enhanced by increasing the spatial diversity in measurements via employing additional cameras for video capture. We compare the performances of various image segmentation techniques in moving-object localization and show that normal-flow-based segmentation yields comparable results to, but requires significantly less time than, optical-flow-based segmentation. We also demonstrate with simulations that dynamic system modeling coupled with the application of an REKF significantly improves the estimation system performance, particularly, when subjected to large uncertainties.

The carbon footprint of an Australian satellite haemodialysis unit

OBJECTIVES This study aimed to better understand the carbon emission impact of haemodialysis (HD) throughout Australia by determining its carbon footprint, the relative contributions of various sectors to this footprint, and how contributions from electricity and water consumption are affected by local factors. METHODS Activity data associated with HD provision at a 6-chair suburban satellite HD unit in Victoria in 2011 was collected and converted to a common measurement unit of tonnes of CO2 equivalents (t CO2-eq) via established emissions factors. For electricity and water consumption, emissions factors for other Australian locations were applied to assess the impact of local factors on these footprint contributors. RESULTS In Victoria, the annual per-patient carbon footprint of satellite HD was calculated to be 10.2t CO2-eq. The largest contributors were pharmaceuticals (35.7%) and medical equipment (23.4%). Throughout Australia, the emissions percentage attributable to electricity consumption ranged from 5.2% to 18.6%, while the emissions percentage attributable to water use ranged from 4.0% to 11.6%. CONCLUSIONS State-by-state contributions of energy and water use to the carbon footprint of satellite HD appear to vary significantly. Performing emissions planning and target setting at the state level may be more appropriate in the Australian context. What is known about the topic? Healthcare provision carries a significant environmental footprint. In particular, conventional HD uses substantial amounts of electricity and water. In the UK, provision of HD and peritoneal dialysis was found to have an annual per-patient carbon footprint of 7.1t CO2-eq. What does this paper add? This is the first carbon-footprinting study of HD in Australia. In Victoria, the annual per-patient carbon footprint of satellite conventional HD is 10.2t CO2-eq. Notably, the contributions of electricity and water consumption to the carbon footprint varies significantly throughout Australia when local factors are taken into account. What are the implications for practitioners? We recommend that healthcare providers consider local factors when planning emissions reduction strategies, and target setting should be performed at the state, as opposed to national, level. There is a need for more comprehensive and current emissions data to enable healthcare providers to do so.

Simultaneous estimation of optical flow and object state: A modified approach to optical flow calculation

Differential optical flow methods are widely used within the computer vision community. They are classified as being either local, as in the Lucas-Kanade method, or global, as in the Horn-Schunck technique. As the physical dynamics of an object is inherently coupled into the behavior of its image in the video stream, in this paper, we use such dynamic parameter information in calculating optical flow when tracking a moving object using a video stream. Indeed, we use a modified error function in the minimization that contains physical parameter information. Further, the refined estimates of optical flow is used for better estimation of the physical parameters of the object in the simultaneous estimation of optical flow and object state(SEOS).

Robust Video/Ultrasonic Fusion Based Estimation for Automotive Applications

We describe how object estimation by a stationary or a non-stationary camera can be improved using recently-developed robust estimation ideas. The robustness of vision-based systems can be improved significantly by employing a robust extended Kalman filter (REKF). The system performance is also enhanced by increasing the spatial diversity in measurements via employing additional cameras for video capture. We describe a normal-flow based image segmentation technique to identify the object for the application of our proposed state estimation technique. Our simulations demonstrate that dynamic system modelling coupled with the application of a REKF significantly improves the estimation system performance, especially when large uncertainties are present.

The crystal structure of trimesityltin(IV) bromide hemiacetone solvate

Figure 1. Molecular structure for one of the two independent molecules of Mes3SnBr0.5CH3C(0)CH3 (50% probability ellipsoids). Selected bond distances and angles [values for the second molecule follow in square brackets]: Sn-Br(1) 2.547(1) [2.544(1)], Sn-C(1) 2.171(5) [2.161(5)], Sn-C(10) 2.161(5) [2.170(5)], Sn-C(19) 2.176(6) [2.166(5)] Ä; Br(1)-Sn-C(1) 102.8(2) [102.2(1)], Br(1)-Sn-C(10) 99.3(1) [99.4(1)], Br(1)-Sn-C(19) 103.2(1) [104.4(1)], C(1)-SnC(10) 116.3(2) [117.7(2)], C(1)-Sn-C(19) 115.0(2) [115.5(2)], C(10)-Sn-C(19) 116.5(2) [114.2(2)]°.

The determination of all syzygies for the dependent polynomial invariants of the Riemann tensor. I. Pure Ricci and pure Weyl invariants

In this paper, we shall consider all pure Ricci and pure Weyl scalar invariants of any degree, in a four-dimensional Lorentzian space. We present a general graph-theoretic based reduction algorithm which decomposes, using syzygies, any pure invariant in terms of the independent base invariants {r1,r2,r3} or {w1,w2} [E. Zakhary and J. Carminati, J. Math. Phys. 42, 1474 (2001)].

Electrospray Mass Spectrometric Studies on the Solution Chemistry of Triorganostannyl Trifluoromethanesulfonates

Compounds of the type R3Sn(OSO2CF3) (triorganostannyl trifluoromethanesulfonates, R = Me, Bu, Ph) were synthesized and investigated in solution using electrospray mass spectrometry. The mono-acetonitrile adduct [R3Snz(CH3CN)]+ is the dominant ionic species in acetonitrile solution, with a weaker signal owing to R3Sn+. The relative intensity of R3Sn+ increases significantly upon the use of dichloromethane as a solvent. Variable temperature 119Sn NMR studies were also undertaken on the trimethylstannyl and triphenylstannyl trifluoromethanesulfonates in dichloromethane solution. The 119Sn chemical shifts and Lewis-base adduction studies reveal that the trioganostannyl trifluoromethanesulfonates are only slightly more Lewis-acidic than the corresponding triorganostannyl chlorides. These solutions are too labile to be studied on the NMR timescale.

ON THE CONSTRUCTION OF SYZYGIES OF THE POLYNOMIAL INVARIANTS OF THE RIEMANN TENSOR

This thesis introduces a novel way of writing polynomial invariants as network graphs, and applies this diagrammatic notation scheme, in conjunction with graph theory, to derive algorithms for constructing relationships (syzygies) between different invariants. These algorithms give rise to a constructive solution of a longstanding classical problem in invariant theory.

The gas-phase fragmentation of trineopentylstannyl cation: a rare example of β-methyl migration within a main group organometallic compound

The lowest-energy fragmentation pathway of trineopentylstannyl cation is the first example of β-methyl migration to an organotin compound in the gas-phase; the origin of the migrating methyl groups is confirmed by an isotopic labelling experiment.