5,175 research outputs found
Depth estimation of metallic objects using multiwavelets scale-space representation
The problem of dimensional defects in aluminum die-castings is widespread throughout the foundry industry and their detection is of paramount importance in maintaining product quality. Due to the unpredictable factory environment and metallic with highly reflective nature, it is extremely hard to estimate true dimensionality of these metallic parts, autonomously. Some existing vision systems are capable of estimating depth to high accuracy, however are very much hardware dependent, involving the use of light and laser pattern projectors, integrated into vision systems or laser scanners. However, due to the reflective nature of these metallic parts and variable factory environments, the aforementioned vision systems tend to exhibit unpromising performance. Moreover, hardware dependency makes these systems cumbersome and costly. In this work, we propose a novel robust 3D reconstruction algorithm capable of reconstructing dimensionally accurate 3D depth models of the aluminum die-castings. The developed system is very simple and cost effective as it consists of only a pair of stereo cameras and a defused fluorescent light. The proposed vision system is capable of estimating surface depths within the accuracy of 0.5mm. In addition, the system is invariant to illuminative variations as well as orientation and location of the objects on the input image space, making the developed system highly robust. Due to its hardware simplicity and robustness, it can be implemented in different factory environments without a significant change in the setup. The proposed system is a major part of quality inspection system for the automotive manufacturing industry. <br /
Stereo correspondence estimation using multiwavelets scale-space representation-based multiresolution analysis
A multiresolution technique based on multiwavelets scale-space representation for stereo correspondence estimation is presented. The technique uses the well-known coarse-to-fine strategy, involving the calculation of stereo correspondences at the coarsest resolution level with consequent refinement up to the finest level. Vector coefficients of the multiwavelets transform modulus are used as corresponding features, where modulus maxima defines the shift invariant high-level features (multiscale edges) with phase pointing to the normal of the feature surface. The technique addresses the estimation of optimal corresponding points and the corresponding 2D disparity maps. Illuminative variation that can exist between the perspective views of the same scene is controlled using scale normalization at each decomposition level by dividing the details space coefficients with approximation space. The problems of ambiguity, explicitly, and occlusion, implicitly, are addressed by using a geometric topological refinement procedure. Geometric refinement is based on a symbolic tagging procedure introduced to keep only the most consistent matches in consideration. Symbolic tagging is performed based on probability of occurrence and multiple thresholds. The whole procedure is constrained by the uniqueness and continuity of the corresponding stereo features. The comparative performance of the proposed algorithm with eight famous existing algorithms, presented in the literature, is shown to validate the claims of promising performance of the proposed algorithm. <br /
Knowledge, attitudes and practices of barbers about hepatitis B and C transmission in Hyderabad, Pakistan.
Hepatitis B and C virus (HBV/HCV) infections are serious global health problems. Shaving by barbers has been identified as the key risk factor for spread of HBV. We conducted a cross-sectional survey of barbers in Hyderabad city, Pakistan in 2007 to establish their knowledge and attitudes to the risk of HBV and HCV transmission and their working patterns. Observations showed that 96.2% washed razors with antiseptic after each client and 95.7% used a new blade with new clients. However, knowledge about the diseases and modes of transmission were poor and only 36.6% knew that hepatitis can be transmitted via shaving instruments. Only 3.2% of 186 barbers were vaccinated against HBV. Strategies are needed for raising awareness and regulations of barbers\u27 practices
Frequency of Predisposing Factor of Nausea and Vomiting After Chest Surgery Under General Anaesthesia
Background: Postoperative nausea and vomiting are common and distressing postsurgical symptoms. These symptoms are of particular concern in outpatient surgery because they may require additional direct resources, such as supplies and antiemetic drugs, and may delay discharge. The objective of this study was to measure the frequency of factors which can cause nausea and vomiting under general anaesthesia after chest surgery.
Methodology: This descriptive case series evaluated frequency of predisposing factor of nausea and vomiting in patients of anaesthesia department of Gulab Devi Hospital Lahore. Questionnaire is made and patients were asked about their age, fever, previous surgery, NPO status, smoking history and hospital stay. This study included 140 patients with post-operative nausea and vomiting.
Results: In this study, 140 patients were taken in which 65 (46.43%) were female and 75 (53.57%) were male. In 140 patient 134 (95.7%) were NPO and 6 (4.3%) were not NPO, 25 (17.9%) were obese and 115 (82.1%) were not obese, 88 (62.9%) patients were suffering fever and 52 (37.1%) were not suffering fever, 80 (57.1%) were infected and 59 (42.1%) were not infected, 53 (37.9%) patients had previous surgery and 87 (62.1%) had no previous surgery, 94 (67.1%) patients had received nitrous oxide and 46 (32.9%) didn\u27t, 97 (69.3%) received volatile gases and 43 (30.7%) not received, 29 (20.7%) received ketamine and 111 (79.3%) not received, 87 (62.1%) received suxamethonium and 53 (37.9%) not received, 119 (85.0%) received propofol and 21 (15.0%) not received, 110 (78.6%) received naluphine and 28 (20.0%) not received. Out of 140 patients, there were 122 (87.1%) who were suffering from pain and 18 (12.9%) were not. 91 (65.0%) patients had gastric distention and 49 (35.0%) patients didn\u27t. Opioids were given to 34 (24.3%) patients and not given to 106 (75.7%) patient.
Conclusion: It is concluded that the nausea and vomiting after surgey under genral anesthesia is due to patient related factors in which most frequent is NPO. Drug related factors include propofol and nalbupin administration. Post operative factors include pain. In whole study of 140 patients, the most frequent is patient related factor (NPO) other than drug related factors and post-operative factors
Ogbu and the debate on educational achievement: an exploration of the links between education, migration, identity and belonging
This paper looks at some of the issues raised by Ogbuās work in relation to the education of different minority ethnic groups. Ogbu poses questions such as the value attached to education,
its links to the future and its measurable outcomes in terms of āsuccessā as experienced by black participants. The desire for better life chances leads families to consider migration to a new country or resettlement within the same country, thus making migration both a local and a global phenomenon. As an example, attention is drawn to the situation facing South Asian
children and their families in the UK. In terms of ethnicity and belonging, the wider question that is significant for many countries in the West after āNine-Elevenā is the education of Muslim children. A consideration of this current situation throws Ogbuās identification of āautonomous minorityā into question. It is argued that a greater understanding of diverse needs has to be
accompanied by a concerted effort to confront racism and intolerance in schools and in society, thus enabling all communities to make a useful contribution and to avoid the āriskā of failure and disenchantment
Nevirapine (NVP) vs ritonavir-boosted atazanavir (ATV/r) combined with tenofovir/emtricitabine (TDF/FTC) in first-line therapy: NEWART 48-week data
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