Segmentation and recognition using structure from motion point clouds

We propose an algorithm for semantic segmentation based on 3D point clouds derived from ego-motion. We motivate five simple cues designed to model specific patterns of motion and 3D world structure that vary with object category. We introduce features that project the 3D cues back to the 2D image plane while modeling spatial layout and context. A randomized decision forest combines many such features to achieve a coherent 2D segmentation and recognize the object categories present. Our main contribution is to show how semantic segmentation is possible based solely on motion-derived 3D world structure. Our method works well on sparse, noisy point clouds, and unlike existing approaches, does not need appearance-based descriptors. Experiments were performed on a challenging new video database containing sequences filmed from a moving car in daylight and at dusk. The results confirm that indeed, accurate segmentation and recognition are possible using only motion and 3D world structure. Further, we show that the motion-derived information complements an existing state-of-the-art appearance-based method, improving both qualitative and quantitative performance. © 2008 Springer Berlin Heidelberg.

Gaussian process change point models

We combine Bayesian online change point detection with Gaussian processes to create a nonparametric time series model which can handle change points. The model can be used to locate change points in an online manner; and, unlike other Bayesian online change point detection algorithms, is applicable when temporal correlations in a regime are expected. We show three variations on how to apply Gaussian processes in the change point context, each with their own advantages. We present methods to reduce the computational burden of these models and demonstrate it on several real world data sets. Copyright 2010 by the author(s)/owner(s).

Marketing of small indigenous species of fish (SIS) in three selected fish markets of Mymensingh

A socio-economic survey was conducted round the year in three fish markets at Mymensingh, Bangladesh. The selected markets were categorized as rural market (Sutiakhali market), a peri-urban market (Kamal Ranjeet market, BAU) and an urban market (Notun Bazar market, Mymensingh town). It was learnt from the survey that the availability of Small Indigenous Fish Species (SIS) declined to a great extent over the last few years and at presently many of such fish species are either threatened or at the edge of extinction. The supply of SIS was highest in KR market (37% of total) and more or less similar in Notun Bazar and Sutiakhali fish market (25 and 27% respectively). The total supply of SIS fluctuated from 25% to 35% throughout the year in these markets. About 48 SIS were found in the sampled markets over the survey period. The highest number of species (45) was found in KR market followed by Notun Bazar (42) and Sutiakhali (37) fish markets. During the survey, three critically endangered species namely, schilbid catfish, garua catfish and rita were found in these markets. Beside these, other 11 and 10 species were listed to be endangered and vulnerable respectively. The biodiversity of 21 SIS found in three markets were no threat at all. Three species (guntea loach, Indian glass barb and flying barb) were 'data deficient' as reported by the IUCN Red Book (IUCN-Bangladesh 2000). From the supply point of view small prawn, spotted snakehead, stinging catfish, pool barb, striped dwarf catfish, Gangetic mystus, walking catfish and tank goby were the prominent fish. The least available species found in this survey were lesser spiny eel, barred spiny eel, Gangetic ailia, freshwater garfish, zig-zag eel, flying barb, Ganges river sprat, freshwater river shad and dwarf gourami. The weight of SIS available in Notun bazar was highest and nearly double than other two markets. There was no significant difference recorded in the supply of SIS in Sutiakhali and KR markets. The average monthly SIS supply was 185, 192 and 467 kg in KR, Sutiakhali and Notun Bazar, respectively; therefore, the cumulative average supply was 844 kg per month in three markets. The price of SIS ranged widely from taka 50-450/kg depending on species, location of market, time of purchase and the condition of fish. In general small prawn, ticto barb, dwarf gourami, Gangetic leaffish, and Annandale loach were sold at a lower price (ranged taka 50-100/kg) and these species could be considered at the bottom of the market-price list. Other SIS like walking catfish, climbing parch, butter catfish, cotio and schilbid catfish valued as highest price (ranged taka 150-450/kg). There was no specific marketing chain for SIS in Mymensingh region. The components of marketing channels and their expansion varied with seasons and locations. The general pattern, however, was as this - after buying fish from fish farmer/fishermen, middlemen (locally known as Foria) used to buy fish to wholesale market and sell to the wholesalers. The retailers used to buy fish from wholesaler through auction to the highest bidders. The retailers then send the fish to particular market where the fish reached the consumers. The livelihood strategy of SIS retailers in three fish markets showed that socio-economic constraints such as low income, poor educational background, low economic status and lack of capital are the main constrains [sic]. Most of the retailers proposed that government should control the fish price throughout the year, so that the producers can get reasonable and stable price. Construction of cold storage and preservation facilities at market sites, improvement of road and communication, improvement of physical market facilities and reduction of market chain is essential. Credit facilities, improvement of their standard of living, health and sanitary condition, housing condition, children education and access to drinking water facilities were identified as additional aspects to improve socio-economic condition of SIS retailers.

Application of the fixed point method for solution in time stepping finite element analysis using the inverse vector Jiles-Atherton model

An implementation of the inverse vector Jiles-Atherton model for the solution of non-linear hysteretic finite element problems is presented. The implementation applies the fixed point method with differential reluctivity values obtained from the Jiles-Atherton model. Differential reluctivities are usually computed using numerical differentiation, which is ill-posed and amplifies small perturbations causing large sudden increases or decreases of differential reluctivity values, which may cause numerical problems. A rule based algorithm for conditioning differential reluctivity values is presented. Unwanted perturbations on the computed differential reluctivity values are eliminated or reduced with the aim to guarantee convergence. Details of the algorithm are presented together with an evaluation of the algorithm by a numerical example. The algorithm is shown to guarantee convergence, although the rate of convergence depends on the choice of algorithm parameters. © 2011 IEEE.

Effect of bend orientation on life and puncture point location due to solid particle erosion of a high concentration flow in pneumatic conveyors

An investigation into predicting failure of pneumatic conveyor pipe bends due to hard solid particle impact erosion has been carried out on an industrial scale test rig. The bend puncture point locations may vary with many factors. However, bend orientation was suspected of being a main factor due to the biased particle distribution pattern of a high concentration flow. In this paper, puncture point locations have been studied with different pipe bend orientations and geometry (a solids loading ratio of 10 being used for the high concentration flow). Test results confirmed that the puncture point location is indeed most significantly influenced by the bend orientation (especially for a high concentration flow) due to the biased particle distribution and biased particle flux distribution. © 2004 Elsevier B.V. All rights reserved.

Sound radiation from point-excited structures: Comparison of plate and sphere

Acoustic radiation from a structure can be expressed in terms of modal radiation and modal coefficients. This paper investigates the contributions of these two modal properties to radiation excited by a point force. Sound radiation from two basic structures is considered: a baffled rectangular plate and a closed spherical shell. The plate behaviour is familiar, and governed by the relation between the natural frequency of a mode and its coincidence frequency. For a closed spherical shell, there are either zero or two critical frequencies, depending on the radius and thickness. When there are two the shell radiates well both above and below the two frequencies, and poorly in the frequency range between them. © 2012 Elsevier Ltd. All rights reserved.

A starting point for addressing product innovativeness in the Fuzzy Front-End

Product innovativeness is a primary contingent factor to be addressed for the development of flexible management for the front-end. However, due to complexity of this early phase of the innovation process, the definition of which attributes to customise is critical to support a contingent approach. Therefore, this study investigates front-end attributes that need to be customised to permit effective management for different degrees of innovation. To accomplish this aim, a literature review and five case studies were performed. The findings highlighted the front-end strategic and operational levels as factors influencing the front-end attributes related to product innovativeness. In conclusion, this study suggests that two front-end attributes should be customised: development activities and decision-making approach. Copyright © 2011 Inderscience Enterprises Ltd.

Parameters identification by a single point free response measurement

When a thin rectangular plate is restrained on the two long edges and free on the remaining edges, the equivalent stiffness of the restraining joints can be identified by the order of the natural frequencies obtained using the free response of the plate at a single location. This work presents a method to identify the equivalent stiffness of the restraining joints, being represented as simply supporting the plate but elastically restraining it in rotation. An integral transform is used to map the autospectrum of the free response from the frequency domain to the stiffness domain in order to identify the equivalent torsional stiffness of the restrained edges of the plate and also the order of natural frequencies. The kernel of the integral transform is built interpolating data from a finite element model of the plate. The method introduced in this paper can also be applied to plates or shells with different shapes and boundary conditions. © 2011 Elsevier Ltd. All rights reserved.

Model structure and uncertainty for stochastic non-point source modelling applications

The uncertainty associated with a rainfall-runoff and non-point source loading (NPS) model can be attributed to both the parameterization and model structure. An interesting implication of the areal nature of NPS models is the direct relationship between model structure (i.e. sub-watershed size) and sample size for the parameterization of spatial data. The approach of this research is to find structural limitations in scale for the use of the conceptual NPS model, then examine the scales at which suitable stochastic depictions of key parameter sets can be generated. The overlapping regions are optimal (and possibly the only suitable regions) for conducting meaningful stochastic analysis with a given NPS model. Previous work has sought to find optimal scales for deterministic analysis (where, in fact, calibration can be adjusted to compensate for sub-optimal scale selection); however, analysis of stochastic suitability and uncertainty associated with both the conceptual model and the parameter set, as presented here, is novel; as is the strategy of delineating a watershed based on the uncertainty distribution. The results of this paper demonstrate a narrow range of acceptable model structure for stochastic analysis in the chosen NPS model. In the case examined, the uncertainties associated with parameterization and parameter sensitivity are shown to be outweighed in significance by those resulting from structural and conceptual decisions. © 2011 Copyright IAHS Press.