Object Registration in Semi-cluttered and Partial-occluded Scenes for Augmented Reality

This paper proposes a stable and accurate object registration pipeline for markerless augmented reality applications. We present two novel algorithms for object recognition and matching to improve the registration accuracy from model to scene transformation via point cloud fusion. Whilst the first algorithm effectively deals with simple scenes with few object occlusions, the second algorithm handles cluttered scenes with partial occlusions for robust real-time object recognition and matching. The computational framework includes a locally supported Gaussian weight function to enable repeatable detection of 3D descriptors. We apply a bilateral filtering and outlier removal to preserve edges of point cloud and remove some interference points in order to increase matching accuracy. Extensive experiments have been carried to compare the proposed algorithms with four most used methods. Results show improved performance of the algorithms in terms of computational speed, camera tracking and object matching errors in semi-cluttered and partial-occluded scenes

Appeals to evidence for the resolution of wicked problems: the origins and mechanisms of evidentiary bias

Wicked policy problems are often said to be characterized by their ‘intractability’, whereby appeals to evidence are unable to provide policy resolution. Advocates for ‘Evidence Based Policy’ (EBP) often lament these situations as representing the misuse of evidence for strategic ends, while critical policy studies authors counter that policy decisions are fundamentally about competing values, with the (blind) embrace of technical evidence depoliticizing political decisions. This paper aims to help resolve these conflicts and, in doing so, consider how to address this particular feature of problem wickedness. Specifically the paper delineates two forms of evidentiary bias that drive intractability, each of which is reflected by contrasting positions in the EBP debates: ‘technical bias’ - referring to invalid uses of evidence; and ‘issue bias’ - referring to how pieces of evidence direct policy agendas to particular concerns. Drawing on the fields of policy studies and cognitive psychology, the paper explores the ways in which competing interests and values manifest in these forms of bias, and shape evidence utilization through different mechanisms. The paper presents a conceptual framework reflecting on how the nature of policy problems in terms of their complexity, contestation, and polarization can help identify the potential origins and mechanisms of evidentiary bias leading to intractability in some wicked policy debates. The discussion reflects on whether being better informed about such mechanisms permit future work that may lead to strategies to mitigate or overcome such intractability in the future

Inpact of small dam on chnges of fish fauna in sitna stream during period of nine years (buffer zone Of Drawieński National Park)

Wielu autorów wskazuje na negatywny wpływ budowli hydrotechnicznych na strukturę nie tylko ichtiofauny, ale również innych organizmów wodnych [14÷16]. Dotyczy to szczególnie poprzecznych przegród wód płynących dzielących ciek na dwie różne pod względem hydrologicznym, biologicznym i ekologicznym części [2, 13]. W wyniku zabudowy rzeki dochodzi do zasadniczych dla organizmów wodnych zmian. Powstaje wówczas bariera ekologiczna z siedliskiem niesprzyjającym do wymagań większości organizmów typowych dla wód płynących [11]. Zdecydowana większość badań oddziaływania zapór wodnych na stan ichtiofauny dotyczy raczej dużych konstrukcji hydrotechnicznych. Pomija się przy tym, małą zabudowę hydrotechniczną przegradzającą małe rzeki i cieki [11], które dla większości ryb anadromicznych stanowią najważniejsze miejsce w ich całym cyklu życiowym - tarlisko. Mała zabudowa poprzeczna, podobnie jak zapory przegradzające duże rzeki w podobnym stopniu zmieniają warunki hydrologiczne i biologiczne cieku, powodując całkowity zanik miejsc do odbycia tarła przez cenne ryby reofilne oraz zdecydowanie zmieniając skład jakościowy i ilościowy ichtiofauny. Celem pracy było określenie wpływu niewielkiej zapory na zmiany struktury jakościowej i ilościowej ichtiofauny w niewielkim cieku Sitna.Many authors point out the negative impact of hydraulic engineering constructions, not only on the structure of fish fauna, but also other aquatic organisms. This applies particularly to transverse bulkheads dividing the flowing waters into two different parts in terms of hydrological, biological and environmental components. Most studies relate to large rivers, where with no doubt it was found that the dams change physicochemical conditions of water. Research in this study was conducted in Sitna stream located in the buffer zone of Drawieński National Park (DNP), a part of the central Drava basin. This fiveorder, right tributary of middle Drawa river, flows into Adamowo Lake. Drawa river flowing out from Adamowo Lake is the northern border of the DNP (Fig. 1). In 2005, on kilometers section of stream water swelling dam was built by the State Forests plantation forest. During the year the water swells to a height of about 50 to 100 cm. The study of fish fauna of Sitna were conducted in August 2000, 2006 and 2009. In order to determine the species composition of fish fauna and the length of individual fish, the fish were obtained using the battery unit IUP 12. Catches were conducted throughout the length of watercourse. The results of the research show that a small dam influences very negatively on changes in the composition of fish fauna in small stream. Results also show that a small dam on a small watercourse, significantly affects the fish fauna. After the building of river dam the number of cyprinids significantly increased. While the number of typical river species, particularly brown trout and gudgeon essentially decreased. Besides, in the watercourse the rapid increase of pike was observed. This species found in the watercourse good spawning conditions. In last year of the study, 2009 in stream section over the dam the river species were absent. Currently, the section suitable for salmonids is the section below the dam. It seems that also in this section, the hydrological conditions will be worse and river fish will be absent in the whole watercourse. It is expected that a progressive changes will lead in consequence to the total extinction of valuable species of fish and to irreversible changes both biological and abiotic

Automated dimensional compliance assessment with incomplete point cloud

Dimensional compliance assessment of prefabricated assemblies is a critical part of mitigating rework on heavy industrial construction projects. As assemblies become more complex, manual direct contact metrology becomes ineffective at detecting fabrication error and so automated alternatives that offer objective, fast, and continuous data collection must be explored. Nahangi and Haas (2014) developed an automated method for assessing pipe spools through an algorithm that compares as-built laser scans to 3D design files. The tool is capable of automatic and continual monitoring of prefabricated assemblies throughout their lifecycle and enables timely detection and quantification of dimensional non-compliance. In the original publication, the tool was validated using ideal input data. In this paper, the tool is tested for robustness when processing incomplete point cloud input data. Non-ideal input data is a risk associated with unfavorable conditions in the fabrication environment such as random assembly occlusions causing blind spots in sensing setup, budgetary constraints limiting the purchase of sensing equipment/viewpoints, and random hardware or software failures resulting in corrupt data. The tool was found to reliably detect dimensional non-compliance so long as the non-compliance indicator (pipe spool feature distinguishing the non-compliant state from the design state) was not fully occluded. Accuracy of non-compliance quantification was predominantly high, however, loosely proportional to the input point cloud’s coverage of the assembly’s surface area.Non UBCUnreviewedFacultyOthe

Zooplankton trzech przymiejskich jezior na tle wybranych warunków abiotycznych

Badania prowadzono w trzech eutroficznych jeziorach położonych w północno-zachodniej Polsce: jeziorze Adamowo, Grażyna i Klasztorne. Z każdego stanowiska pobierano próbę zooplanktonu oraz próbę wody do określenia wybranych parametrów fizyko-chemicznych. W odniesieniu do uzyskanych wyników można uznać, że pomimo takiego samego statusu troficznego badane jeziora różniły się pod względem struktur jakościowych i ilościowych zooplanktonu, na co miały wpływ różne warunki środowiskowe badanych jezior. Podobieństwo jakościowe zooplanktonu pomiędzy jeziorami nie było zbyt wysokie. W najmniejszym jeziorze obserwowano największe liczebności zooplanktonu, szczególnie małych plankterów. Pozwala to wnioskować, że im mniejsza powierzchnia jeziora tym większa jest liczebność zasiedlającego je zooplanktonu. Biomasa zooplanktonu osiągała największe wartości w największym jeziorze Adamowo, co było spowodowane licznym występowaniem dojrzałych skorupiaków planktonowych. Biorąc pod uwagę zależność pomiędzy warunkami środowiskowymi jezior a zagęszczeniem zooplanktonu, stwierdzić można że największy wpływ na kształtowanie struktur zooplanktonu mają nieorganiczne związki biogenne

An image-based frameworks for automated discrepancy quantification and realignment of industrial assemblies

Image-based frameworks for automated as-built modeling and infrastructure 3D reconstruction are increasingly being used in the construction industry. The increasing use of image-based technologies in the construction processes is due to the ease of application, cheap cost of enhancement, time effectiveness and high level of accuracy and automation. Automating the tasks involved in the inspection, quality control and quality assurance (QA/QC) processes are the potential avenues for utilizing such frameworks. This paper presents an image-based approach for acquiring the built status of fabricated assemblies and describes a framework for realigning the defective segments by borrowing concepts from robotics and forward kinematics. A laboratory set of experiments is then conducted to measure the accuracy and performance of the proposed framework for realignment of industrial facilities, in general, and pipe spools, in particular. Results demonstrate that it can be utilized in real cases providing the required level of accuracy as well.Non UBCUnreviewedFacult