Alen Alempijevic

Dr. Alen Alempijevic

orcid

Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2012
Verified
Conference Paper
Closed access
GHGibson Hu
Gibson Hu
SHShoudong Huang
Shoudong Huang
LZLiang Zhao
Liang Zhao
AAAlen Alempijevic
Alen Alempijevic
GDGamini Dissanayake
Gamini Dissanayake
Recently RGB-D sensors have become very popular in the area of Simultaneous Localisation and Mapping (SLAM). The major advantage of these sensors is that they provide a rich source of 3D information at relatively low cost. Unfortunately, these sensors in their current forms only have a range accuracy of up to 4 metres. Many techniques which perform SLAM using RGB-D cameras rely heavily on the depth and are restrained to office type and geometrically structured environments. In this paper, a switching based algorithm is proposed to heuristically choose between RGB-BA and RGBD-BA based local maps building. Furthermore, a low cost and consistent optimisation approach is used to join these maps. Thus the potential of both RGB and depth image information are exploited to perform robust SLAM in more general indoor cases. Validation of the proposed algorithm is performed by mapping a large scale indoor scene where traditional RGB-D mapping techniques are not possible.


26 September 2017 in Sensors
Verified
Journal Article
Open access
PDF file
NUNalika Ulapane
Nalika Ulapane
AAAlen Alempijevic
Alen Alempijevic
TCTeresa Vidal Calleja
Teresa Vidal Calleja
Jaime Valls MiroJaime Valls Miro
Jaime Valls Miro
Pulsed Eddy Current (PEC) sensing is used for Non-Destructive Evaluation (NDE) of the structural integrity of metallic structures in the aircraft, railway, oil and gas sectors. Urban water utilities also have extensive large ferromagnetic structures in the form of critical pressure pipe systems made of grey cast iron, ductile cast iron and mild steel. The associated material properties render NDE of these pipes by means of electromagnetic sensing a necessity. In recent years PEC sensing has established itself as a state-of-the-art NDE technique in the critical water pipe sector. This paper presents advancements to PEC inspection in view of the specific information demanded from water utilities along with the challenges encountered in this sector. Operating principles of the sensor architecture suitable for application on critical pipes are presented with the associated sensor design and calibration strategy. A Gaussian process-based approach is applied to model a functional relationship between a PEC signal feature and critical pipe wall thickness. A case study demonstrates the sensor’s behaviour on a grey cast iron pipe and discusses the implications of the observed results and challenges relating to this application.

1 October 2007
Verified
Conference Paper
Closed access
SSStephan Sehestedt
Stephan Sehestedt
SKSarath Kodagoda
Sarath Kodagoda
AAAlen Alempijevic
Alen Alempijevic
GDGamini Dissanayake
Gamini Dissanayake
Most of the lane marking detection algorithms reported in the literature are suitable for highway scenarios. This paper presents a novel clustered particle filter based approach to lane detection, which is suitable for urban streets in normal traffic conditions. Furthermore, a quality measure for the detection is calculated as a measure of reliability. The core of this approach is the usage of weak models, i.e. the avoidance of strong assumptions about the road geometry. Experiments were carried out in Sydney urban areas with a vehicle mounted laser range scanner and a ccd camera. Through experimentations, we have shown that a clustered particle filter can be used to efficiently extract lane markings.

1 May 2011
Verified
Conference Paper
Closed access
SOSimon T. O'CAllaghan
Simon T. O'CAllaghan
SSSurya P. N. Singh
Surya P. N. Singh
AAAlen Alempijevic
Alen Alempijevic
FRFabio T. Ramos
Fabio T. Ramos
Observing human motion patterns is informative for social robots that share the environment with people. This paper presents a methodology to allow a robot to navigate in a complex environment by observing pedestrian positional traces. A continuous probabilistic function is determined using Gaussian process learning and used to infer the direction a robot should take in different parts of the environment. The approach learns and filters noise in the data producing a smooth underlying function that yields more natural movements. Our method combines prior conventional planning strategies with most probable trajectories followed by people in a principled statistical manner, and adapts itself online as more observations become available. The use of learning methods are automatic and require minimal tuning as compared to potential fields or spline function regression. This approach is demonstrated testing in cluttered office and open forum environments using laser and vision sensing modalities. It yields paths that are similar to the expected human behaviour without any a priori knowledge of the environment or explicit programming.

6 March 2011
Verified
Conference Paper
Open access
PDF file
NKNathan Kirchner
Nathan Kirchner
AAAlen Alempijevic
Alen Alempijevic
GDGamini Dissanayake
Gamini Dissanayake