A highly accurate and scalable approach for addressing location uncertainty in asset tracking applications

Tracking systems that use RFID are increasingly being used for monitoring the movement of goods in supply chains. While these systems are effective, they still have to overcome significant challenges, such as missing reads, to improve their performance further. In this paper, we describe an optimised tracking algorithm to predict the locations of objects in the presence of missed reads using particle filters. To achieve high location accuracy we develop a model that characterises the motion of objects in a supply chain. The model is also adaptable to the changing nature of a business such as flow of goods, path taken by goods through the supply chain, and sales volumes. A scalable tracking algorithm is achieved by an object compression technique, which also leads to a significant improvement in accuracy. The results of a detailed simulation study shows that our object compression technique yields high location accuracy (above 98% at 0.95 read rate) with significant reductions in execution time and memory usage.Rengamathi Sankarkumar, Damith C. Ranasinghe, Thuraiappah Sathya

An extended Kalman filter for localisation in occupancy grid maps

© 2015 IEEE. The main contribution of this paper is an extended Kalman filter (EKF) based framework for mobile robot localisation in occupancy grid maps (OGMs), when the initial location is approximately known. We propose that the observation equation be formulated using the unsigned distance transform based Chamfer Distance (CD) that corresponds to a laser scan placed within the OGM, as a constraint. This formulation provides an alternative to the ray-casting model, which generally limited localisation in OGMs to Particle Filter (PF) based frameworks that can efficiently deal with observation models that are not analytic. Usage of an EKF is attractive due to its computational efficiency, especially as it can be applied to modern day field robots with limited on-board computing power. Furthermore, well-developed tools for dealing with potential outliers in the observations or changes to the motion model, exists in the EKF framework. The effectiveness of the proposed algorithm is demonstrated using a number of simulation and real life examples, including one in a dynamic environment populated with people

Fast global scan matching for high-speed vehicle navigation

© 2015 IEEE. This paper presents a fast global scan matching technique for high-speed vehicle navigation. The proposed grid-based scan-to-map matching technique collectively handles unprocessed scan points at each grid cell as a grid feature. The grid features are transformed and located in the global frame and updated every time a new scan is acquired. Since registered and updated are only grid features, which are each the mean of scan points in a grid cell, the proposed grid feature matching technique is very fast. Representation for each grid cell by multiple grid features further maintains accuracy regardless of the grid size while fast processing is achieved. The technique is therefore suited for localization of high-speed vehicle navigation. Experimental results show the effectiveness of the proposed technique numerically and experimentally

Climate change-driven losses in ecosystem services of coastal wetlands: A case study in the West coast of Bangladesh

© 2018 The Authors Climate change is globally recognized as one of the key drivers of degradation of coastal wetland ecosystems, causing considerable alteration of services provided by these habitats. Quantifying the physical impacts of climate change on these services is therefore of utmost importance. Yet, practical work in this field is fragmented and scarce in current literature, especially in developing countries which are likely to suffer most from the adverse climate change impacts. Using a coherent scenario-based approach that combines assessment of physical impacts with economic valuation techniques, here we quantify potential climate change driven losses in the value of wetland ecosystems services due to relative sea-level rise (RSLR)-induced inundation in the vulnerable Western coastal area of Bangladesh in 2100. The results show a small inundation area in 2100 under the three IPCC climate scenarios of RCP2.6 (with 0.25 m of RSLR), RCP6.0 (with 1.18 m of RSLR), and RCP8.5 (with 1.77 m of RSLR) for the coastal wetland ecosystems including the Sundarbans mangrove forest, neritic system and aquaculture ponds. In all scenarios, RSLR will drive a loss in the total value of ecosystem services such as provision of raw materials, and food provision, ranging from US$0–1 million to US$ 16.5–20 million, respectively. The outcomes of this study reveal that RSLR-induced inundation on its own, is unlikely to be a major threat to the wetland ecosystems in Western coast of Bangladesh. This would suggest that other climate change impacts such as coastal erosion, increase in frequency of cyclone events, and sea temperature rise might be the likely primary drivers of change in the value of wetland ecosystems services in this area

Vector Distance Function Based Map Representation for Robot Localisation

This paper introduces the use of the vector distance function (VDF) for representing environments, particularly for the use in localisation algorithms. It is shown that VDF has a continuous derivative at the object boundary in contrast to unsigned distance transform, and does not require an environment populated with closed object as in the case of the signed distance transforms, the two most common strategies reported in the literature for representing environments based on distances to nearest occupied regions. As such VDF overcomes the main disadvantages of the existing distance transform based representations in the context of robot localisation. The key properties of VDF are demonstrated and the use of VDF in robot localisation using an optimization based algorithm is illustrated using three examples. It is shown that the proposed environment representation and the localisation algorithm is effective in providing accurate location estimates as well as the associated uncertaintie

Distance function based 6DOF localization for unmanned aerial vehicles in GPS denied environments

© 2017 IEEE. This paper presents an algorithm for localizing an unmanned aerial vehicle (UAV) in GPS denied environments. Localization is performed with respect to a pre-built map of the environment represented using the distance function of a binary mosaic, avoiding the need for extraction and explicit matching of visual features. Edges extracted from images acquired by an on-board camera are projected to the map to compute an error metric that indicates the misalignment between the predicted and true pose of the UAV. A constrained extended Kalman filter (EKF) framework is used to generate an estimate of the full 6-DOF location of the UAV by enforcing the condition that the distance function values are zero when there is no misalignment. Use of an EKF also makes it possible to seamlessly incorporate information from any other system on the UAV, for example, from its auto-pilot, a height sensor or an optical flow sensor. Experiments using a hexarotor UAV both in a simulation environment and in the field are presented to demonstrate the effectiveness of the proposed algorithm

ALTMM 2018 - 3rd international workshop on multimedia alternate realities

AltMM 2018 is the 3rd edition of the International Workshop on Multimedia Alternate Realities at ACM Multimedia. Our ambition remains to engage researchers and practitioners in discussions on how we can successfully create meaningful multimedia 'alternate realities' experiences. One of the main strengths of this workshop is that we combine different perspectives to explore how the synergy between multimedia technologies can foster and shape the creation of alternate realities and make their access an enriching and valuable experience

Modelling tsunami inundation on coastlines with characteristic form

This paper provides an indication of the likely difference in tsunami amplification and dissipation between different characteristic coastal embayments, coastal entrances and estuaries. Numerical modeling is performed with the ANU/Geoscience Australia tsunami inundation model. Characteristic coastal morphology is represented by simpler generic morphological shapes which can be applied easily in the ANUGA model, such that key non-dimensional parameters (e.g. embayment depth/bay width) can be varied. Modeling is performed with a range of bay shapes, seabed gradient and different incident tsunami wave shapes and wave angles, including sine waves, solitary waves and leading depression Nwaves. The results show a complex pattern for both large and small embayments, with wave breaking an important control on the amplification of the wave between the 20m contour and the shore. For large embayments, the wave run-up can be amplified by a factor six in comparison to the amplitude at the model boundary. For small embayments, the amplification is dependent on the location of the ocean water line, or tidal stage

One Digital Platform to Seek Quality Education for Everyone

The primary goal of this digital educational platform is to deliver high-quality educational possibilities to people looking for a degree or similar graded programs, tuition classes, and postgraduate programs provided by universities internationally and nationally. Furthermore, by advertising on our web platform, educational institutions will be able to improve the popularity of their courses and services.  There will also be the opportunity to donate financial contributions to campaigns or organizations that will help persons in need of educational assistance. In addition, our development team proposed an idea about a component called volunteer support, which allows users to join up as volunteers for specific organizational initiatives that promote educational campaigns. There will also be several account types for system administrators, users searching for services, and organizations promoting educational programs and volunteer opportunities. The account's capabilities differ depending on the type of user account. The primary objectives of this thesis are to provide the concept of a system that simplifies the process of locating and advertising educational needs, opportunities, and services while providing a way to help people in need of a helping hand

Design and Implementation of a Web Application for an E-Plant Store

With the advancement of technology in every industry, finding items with a few clicks is now simpler. Most people do not have enough knowledge about planting and its advantages of it. Therefore, this platform will be very helpful for those who sell and buy plants. Customers cannot compare prices or pay online when it comes to markets or plant nurseries. So, in this case, Plantae.lk offers various opportunities to customers. They can inspect, get details, compare plants’ pricing, and make online payments easily. In this competitive business world, customer satisfaction is extremely important. We want each customer to have a pleasant shopping experience. With that intention, customer support service offers technical advice and guidance when it is needed. This web application also consists of detailed gardening advice. The major goal of this web application is to provide a better business experience for both seller and consumer.([1])([2]