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Sample records for swainsonine mycotoxicosis pose

  1. Swainsonine promotes apoptosis in human oesophageal squamous ...

    Indian Academy of Sciences (India)

    Swainsonine, a natural indolizidine alkaloid, has been reported to have antitumour effects, and can induce apoptosis in human gastric and lung cancer cells. In the present study, we evaluated the antitumour effects of swainsonine on several oesophageal squamous cell carcinoma cells and investigated relative molecular ...

  2. Swainsonine promotes apoptosis in human oesophageal squamous ...

    Indian Academy of Sciences (India)

    2012-10-24

    Oct 24, 2012 ... The ultrastructural morphology changes were observed un- der a transmission electron microscope. After swainsonine treatment, the cells were fixed with 4% glutaraldehyde, and post-fixed with 1% OsO4. Then samples were dehydrated in graded ethanol solutions, followed by embedment and sec- tion.

  3. Swainsonine biosynthesis genes in diverse symbiotic and pathogenic fungi

    Science.gov (United States)

    Swainsonine, a cytotoxic fungal alkaloid and a potential cancer therapy drug, is produced by the insect pathogen and plant symbiont, Metarhizium robertsii, the clover pathogen Slafractonia leguminicola, locoweed symbionts belonging to Alternaria sect. Undifilum, and a recently discovered morning glo...

  4. Swainsonine Biosynthesis Genes in Diverse Symbiotic and Pathogenic Fungi

    Directory of Open Access Journals (Sweden)

    Daniel Cook

    2017-06-01

    Full Text Available Swainsonine—a cytotoxic fungal alkaloid and a potential cancer therapy drug—is produced by the insect pathogen and plant symbiont Metarhizium robertsii, the clover pathogen Slafractonia leguminicola, locoweed symbionts belonging to Alternaria sect. Undifilum, and a recently discovered morning glory symbiont belonging to order Chaetothyriales. Genome sequence analyses revealed that these fungi share orthologous gene clusters, designated “SWN,” which included a multifunctional swnK gene comprising predicted adenylylation and acyltransferase domains with their associated thiolation domains, a β-ketoacyl synthase domain, and two reductase domains. The role of swnK was demonstrated by inactivating it in M. robertsii through homologous gene replacement to give a ∆swnK mutant that produced no detectable swainsonine, then complementing the mutant with the wild-type gene to restore swainsonine biosynthesis. Other SWN cluster genes were predicted to encode two putative hydroxylases and two reductases, as expected to complete biosynthesis of swainsonine from the predicted SwnK product. SWN gene clusters were identified in six out of seven sequenced genomes of Metarhzium species, and in all 15 sequenced genomes of Arthrodermataceae, a family of fungi that cause athlete’s foot and ringworm diseases in humans and other mammals. Representative isolates of all of these species were cultured, and all Metarhizium spp. with SWN clusters, as well as all but one of the Arthrodermataceae, produced swainsonine. These results suggest a new biosynthetic hypothesis for this alkaloid, extending the known taxonomic breadth of swainsonine producers to at least four orders of Ascomycota, and suggest that swainsonine has roles in mutualistic symbioses and diseases of plants and animals.

  5. Relationship between mycotoxicosis and calcium during preproduction period in layers

    Directory of Open Access Journals (Sweden)

    T. S. Qubih

    2012-01-01

    Full Text Available This study was conducted to examine field cases of mycotoxicosis (A flatoxicosis and ochratoxicosis and their effects on calcium during the preproduction period of 1SA brown pullets. Birds were 12-15 weeks of age. The feed was subjected to analysis for mycotoxin and blood samples were laboratory diagnosed for infectious bronchitis and infectious bursal viruses antibody titer and for determination calcium level. Clinical signs of affected birds were rubbery bone, ruffled feather, paleness and high mortality. Necropsy findings of sick birds were characterized by muscle dehydration, enlarged livers yellowished, kidney enlargement and urate deposition. Histopathological features of liver consisted of capsular thickening hepatocellular necrosis, subcapsular infiltration with inflammatory kidneys cells showed swelling of tubular cells, deposition of calcium between kidney tubules with infiltration of inflammatory cells. ELISA test revealed the presence of 800 ppb aflatoxin and 100 ppb ochratoxin. Normal titers of infectious bronchitis virus and infectious bursal diseases antibodies were recorded. Low blood calcium level of 8.2 mg/dl was registered in the tested blood samples.

  6. Correlation between the limit values of laboratory and clinical mycotoxicosis

    Directory of Open Access Journals (Sweden)

    Stojanov Igor M.

    2013-01-01

    Full Text Available Analysis of feed for the presence of fungi and mycotoxins is a request necessary to meet in order to ensure a healthy and economical production in livestock. These tests are related to legal regulation which prescribes the maximum legislated content (MLC, both for the presence of mycotoxins and the total number of fungi in certain feeds. Health problems that can occur during the production of animals are sometimes caused by the presence of mycotoxins in the feed. Laboratory testing is a good practice to confirm a suspicion, and allows timely treatment of contaminated feed. Potential problems arise under circumstances when there is a clinical outcome of mycotoxicosis and animal and laboratory findings suggest that the obtained values are below the level that is within the MLC. For these reasons, the subject of our research was to investigate the occurrence of mycotoxins and mold in feed, as well as the clinical presentation for animals that were fed with the feed with allowed values of these agents according to the recommended levels. The aim of this paper was to highlight the problems associated with clinical correlation of sick animals and laboratory findings, and suggest their overcoming. In the period of one year, a total of 176 samples of feed (complete mixture for broilers, corn and soy products were examined for the presence of fungi, 106 samples were examined for the presence of mycotoxins and 26 flocks of broilers and turkeys were clinically observed. Standard methods were used for isolation of molds and the ELISA test was used for the detection of mycotoxins. Clinical and pathomorphological observation of the flocks was done to determine the natural indicators of production. Studies indicated a problem because clinical and pathomorphological findings in some cases were not correlated with laboratory findings of molds and mycotoxins in the feed, and in some cases it did not necessarily mean that the animals were healthy. Synergism and

  7. Liver biopsy as diagnostic method for poisoning by swainsonine-containing plants

    Science.gov (United States)

    With the aim to investigate the use of hepatic biopsies for the diagnosis of poisoning by swainsonine-containing plants, dry leaves of Ipomoea marcellia containing 0.02% of swainsonine were administered to goats. Group I, with six goats, ingested 4g/kg of dry plant (0.8mg of swainsonina/kg) until th...

  8. Production of the alkaloid swainsonine by a fungal endosymbiont of the Ascomycete order Chaetothyriales in the host Ipomoea carnea.

    Science.gov (United States)

    Cook, Daniel; Beaulieu, Wesley T; Mott, Ivan W; Riet-Correa, Franklin; Gardner, Dale R; Grum, Daniel; Pfister, James A; Clay, Keith; Marcolongo-Pereira, Clairton

    2013-04-24

    Some plant species within the Convolvulaceae (morning glory family) from South America, Africa, and Australia cause a neurologic disease in grazing livestock caused by swainsonine. These convolvulaceous species including Ipomoea carnea contain the indolizidine alkaloid swainsonine, an inhibitor of α-mannosidase and mannosidase II, and polyhydroxy nortropane alkaloids, the calystegines which are glycosidase inhibitors. Swainsonine has been shown to be produced by a fungal endosymbiont in legumes of the Astragalus and Oxytropis genera, where it causes a similar neurologic disease in grazing livestock called locoism. Here we demonstrate that I. carnea plants are infected with a fungal endosymbiont that was cultured from its seeds and which produced swainsonine in pure culture but not the calystegines. The same fungal endosymbiont was detected by PCR and by culturing in I. carnea plants containing swainsonine. The fungal endosymbiont belongs to the Ascomycete order Chaetothyriales. Plants derived from fungicide-treated seeds lacked swainsonine, but calystegine concentrations were unaltered.

  9. Swainsonine promotes apoptosis in human oesophageal squamous cell carcinoma cells in vitro and in vivo through activation of mitochondrial pathway.

    Science.gov (United States)

    Li, Zhaocal; Huang, Yong; Dong, Feng; Li, Wei; Ding, Li; Yu, Gaoshui; Xu, Dan; Yang, Yuanyuan; Xu, Xingang; Tong, Dewen

    2012-12-01

    Swainsonine, a natural indolizidine alkaloid, has been reported to have antitumour effects, and can induce apoptosis in human gastric and lung cancer cells. In the present study, we evaluated the antitumour effects of swainsonine on several oesophageal squamous cell carcinoma cells and investigated relative molecular mechanisms. Swainsonine treatment inhibited the growth of Eca-109, TE-1 and TE-10 cells in a concentration-dependent manner as measured by MTT assay. Morphological observation, DNA laddering detection and flow cytometry analysis demonstrated that swainsonine treatment induced Eca-109 cell apoptosis in vitro. Further results showed that swainsonine treatment up-regulated Bax, downregulated Bcl-2 expression, triggered Bax translocation to mitochondria, destructed mitochondria integrity and activated mitochondria-mediated apoptotic pathway, followed by the release of cytochrome c, which in turn activated caspase-9 and caspase-3, promoted the cleavage of PARP, resulting in Eca-109 cell apoptosis. Moreover, swainsonine treatment inhibited Bcl-2 expression, promoted Bax translocation, cytochrome c release and caspase-3 activation in xenograft tumour cells, resulting in a significant decrease of tumour volume and tumour weight in the swainsoninetreated xenograft mice groups compared with that in the control group. Taken together, this study demonstrated that swainsonine inhibited Eca-109 cells growth through activation of mitochondria-mediated caspase-dependent pathway.

  10. Hepato nephropathology associated with inclusion body hepatitis complicated with citrinin mycotoxicosis in a broiler farm

    Directory of Open Access Journals (Sweden)

    Asok Kumar Mariappan

    2018-02-01

    Full Text Available Aim: Mortality in a broiler chicken farm was investigated for identifying the cause of mortality. Materials and Methods: A broiler farm with a population of 16000 succumbed to a disease outbreak. Clinical signs, vaccination history and mortality, were recorded. Necropsy examination and microscopic examination were carried out along with toxicological and molecular studies. Results: The clinical signs in the affected broiler birds were of non-specific nature with a total mortality of 26.39%. Postmortem examination and microscopical findings revealed hepatitis with basophilic intranuclear inclusion, splenitis, myocarditis, and nephritis. Glomerulonephritis was the prominent renal pathology recorded in this study. Polymerase chain reaction test confirmed the presence of fowl adenovirus (FAdV genome in the target organs, and toxicological examination by thin-layer chromatography revealed the presence of a toxic level of citrinin in the feed samples. Conclusion: Based on various diagnostic investigations, the mortality in the flock was attributed to inclusion body hepatitis (IBH complicated with citrinin mycotoxicosis. Thus, apart from liver pathology which occurs in a classical IBH cases, glomerulonephritis too occurs which are also a prominent finding which pathologists often miss. Thus, kidneys should also be examined histologically to assess the microscopic tissue alterations in poultry suspected for IBH along with a mycotoxicological analysis of feed. This will definitely throw light on the synergistic pathology elicited and exhibited by FAdV and mycotoxins in the poultry.

  11. The Effect of Experimental Fusarium Mycotoxicosis on Microbiota Diversity in Porcine Ascending Colon Contents

    Directory of Open Access Journals (Sweden)

    Małgorzata Piotrowska

    2014-07-01

    Full Text Available The objective of the study was to determine the effect of exposure of pigs to the Fusarium mycotoxins zearalenone (ZEN and deoxynivalenol (DON, administered together and separately, on the colon microbiota. An experiment was conducted for 42 days on gilts, randomly assigned to four groups and administered either ZEN, DON, ZEN+DON, or a placebo. The number of aerobic mesophilic bacteria, yeasts, molds, anaerobic Clostridium perfringens, fecal streptococci, Enterobacteriaceae, Escherichia coli, and lactic acid bacteria (LAB were determined in the contents of the ascending colon. The influence of mycotoxins on the functional diversity of the colonic microbiota was assessed using EcoPlate tests (Biolog. Analysis revealed the predominance of LAB in all groups of pigs. Zearalenone, administered separately and together with DON, was found to have an adverse effect on mesophilic aerobic bacteria, but only after long exposure to this mycotoxin. During the six weeks of the experiment, the concentration of C. perfringens, E. coli, and other bacteria in the family Enterobacteriaceae was most considerably reduced in the experimental groups exposed to zearalenone, both separately and together with DON. Mycotoxins also affected the functional biodiversity of microorganisms. Both Shannon’s diversity index and the number of catabolized substrates in Biolog plate (the R index were much higher in the group subjected to mixed mycotoxicosis.

  12. Clinical and pathomorphological diagnostics of mycotoxicosis in parent poultry flock caused by T-2 trychotecene

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    Kapetanov Miloš C.

    2013-01-01

    Full Text Available The most relevant mycotoxin from the trychotecene group, T-2, causes prominent citotoxic effects. The toxin is a secondary product of fungi from the genus Fusarium that contaminates feed. Oraly intaken, T-2 is absorbed fast in the upper digestive system and within only 3 to 4 hours later reaches liver, kidneys and muscle tissue. Clinical and pathological changes are sometimes not obvious. The case of mycotoxicosis in a breeder flock of chickens, here presented, is aimed to underline the significance of clinical and pathological diagnosis supported with laboratory analysis that gave an objective causative diagnosis. On the farm, the disease occurred suddenly and with total cessation of feed consumption. First cases were recorded in the flock at the age of 42 weeks. Grouping, intensive breathing and lying with overstretched legs and extended neck were symptoms observed in birds. Evident necrosis of beak tips and painful multi-focal necrosis in oral cavity were recorded during the clinical examination. On section, dark unclothed blood was first observed. Other postmortem findings included: filled gizzard with mucosal erosions and easy-removable cuticle, enlarged congested liver with multi-focal necrosis and subcapsulary bleeding. The mortality rate increased by 4%, and the drop of laying rate was by about 18%. The fertility rate decreased by 22%. There was the increased number of rejected hatching eggs, 12%. Culture of the complete diet resulted in approximately 150000 colonies per 1g of Fusarium. T-2 was detected by using ELISA in concentration of 480 μg/kg, which corresponded to the upper limit of maximum permitted concentrations for chickens, according to national legislations. This bylaw interpretation of “tolerable” concentrations of mycotoxins provokes controversy among experts and public. [Projekat Ministarstva nauke Republike Srbije, br. TR 31071

  13. Degradation of Swainsonine by the NADP-Dependent Alcohol Dehydrogenase A1R6C3 in Arthrobacter sp. HW08

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2016-05-01

    Full Text Available Swainsonine is an indolizidine alkaloid that has been found in locoweeds and some fungi. Our previous study demonstrated that Arthrobacter sp. HW08 or its crude enzyme extract could degrade swainsonie efficiently. However, the mechanism of swainsonine degradation in bacteria remains unclear. In this study, we used label-free quantitative proteomics method based on liquid chromatography-electrospray ionization-tandem mass spectrometry to dissect the mechanism of swainsonine biodegradation by Arthrobacter sp. HW08. The results showed that 129 differentially expressed proteins were relevant to swainsonine degradation. These differentially expressed proteins were mostly related to the biological process of metabolism and the molecular function of catalytic activity. Among the 129 differentially expressed proteins, putative sugar phosphate isomerase/epimerase A1R5X7, Acetyl-CoA acetyltransferase A0JZ95, and nicotinamide adenine dinucleotide phosphate (NADP-dependent alcohol dehydrogenase A1R6C3 were found to contribute to the swainsonine degradation. Notably, NADP-dependent alcohol dehyrodgenase A1R6C3 appeared to play a major role in degrading swainsonine, but not as much as Arthrobacter sp. HW08 did. Collectively, our findings here provide insights to understand the mechanism of swainsonine degradation in bacteria.

  14. Ebishushani: people poses places

    NARCIS (Netherlands)

    Andrea Stultiens

    2014-01-01

    Ebifananyi II – People Poses Places Andrea Stultiens People Poses Places is the second part of Ebifananyi, a book series that visualises historical Ugandan photo collections. In People Poses Places we delve into the archive of the photographer Musa Katuramu. In the mid 1930s, teacher and carpenter

  15. POISONING BY THE SWAINSONINE-CONTAINING PLANT SIDA CARPINIFOLIA IN CAPTIVE SAMBAR DEER (CERVUS UNICOLOR).

    Science.gov (United States)

    Anjos, Bruno L; Peixoto, Paulo V; Caldas, Saulo A; Bhaltazar, Daniel; França, Ticiana N; Armién, Aníbal G

    2016-09-01

    Plant intoxications in wildlife are difficult to diagnose, are overlooked, or are sometimes even neglected. Hence, factors that induce wild animals to ingest poisonous plants have not been sufficiently documented. An outbreak of glycoprotein storage disease in sambar deer ( Cervus unicolor ), induced by ingestion of the swainsonine-containing plant, common wireweed (Sida carpinifolia), is reported. Nine out of 55 deer held by a zoo in Brazil were affected. The poisoning was characterized by emaciation and neurologic signs followed by unexpected death in some of the animals. Animals presented abnormal consciousness, posterior paresis, and musculoskeletal weakness; less evident were vestibulo-cerebellar signs. Histologically, there was vacuolation of neurons and epithelial cells of the pancreatic acines, thyroid follicules, and renal tubules. Furthermore, in the central nervous system were axonal degeneration, necrosis, and loss of neurons. Three factors may lead to the ingestion of S. carpinifolia by sambar deer: 1) A grazing field with only S. carpinifolia as a source of forage; 2) a large number of animals kept in this field; and 3) a hierarchy within a cervid group in which dominant males isolated and displaced juvenile and weaker adult males, leaving them with access to only S. carpinifolia.

  16. Biosynthesis of intestinal microvillar proteins. The effect of swainsonine on post-translational processing of aminopeptidase N

    DEFF Research Database (Denmark)

    Danielsen, E M; Cowell, G M; Norén, Ove

    1983-01-01

    The post-translational processing of pig small-intestinal aminopeptidase N (EC 3.4.11.2) was studied in organ-cultured mucosal explants. Exposure of the explants to swainsonine, an inhibitor of Golgi mannosidase II, resulted in the formation of a Mr-160000 polypeptide, still sensitive to endo...... of the Mr-160000 polypeptide with endo-beta-N-acetylglucosaminidase H only decreased its apparent Mr by 15000. The susceptibility of the mature Mr-166000 polypeptide, but not the Mr-140000 polypeptide, to mild alkaline hydrolysis suggests that aminopeptidase N becomes glycosylated with O...

  17. Pose Space Surface Manipulation

    Directory of Open Access Journals (Sweden)

    Yusuke Yoshiyasu

    2012-01-01

    Full Text Available Example-based mesh deformation techniques produce natural and realistic shapes by learning the space of deformations from examples. However, skeleton-based methods cannot manipulate a global mesh structure naturally, whereas the mesh-based approaches based on a translational control do not allow the user to edit a local mesh structure intuitively. This paper presents an example-driven mesh editing framework that achieves both global and local pose manipulations. The proposed system is built with a surface deformation method based on a two-step linear optimization technique and achieves direct manipulations of a model surface using translational and rotational controls. With the translational control, the user can create a model in natural poses easily. The rotational control can adjust the local pose intuitively by bending and twisting. We encode example deformations with a rotation-invariant mesh representation which handles large rotations in examples. To incorporate example deformations, we infer a pose from the handle translations/rotations and perform pose space interpolation, thereby avoiding involved nonlinear optimization. With the two-step linear approach combined with the proposed multiresolution deformation method, we can edit models at interactive rates without losing important deformation effects such as muscle bulging.

  18. Developmental and loco-like effects of a swainsonine-induced inhibition of α-mannosidase in the honey bee, Apis mellifera.

    Science.gov (United States)

    Wedd, Laura; Ashby, Regan; Foret, Sylvain; Maleszka, Ryszard

    2017-01-01

    Deficiencies in lysosomal a-mannosidase (LAM) activity in animals, caused either by mutations or by consuming toxic alkaloids, lead to severe phenotypic and behavioural consequences. Yet, epialleles adversely affecting LAM expression exist in the honey bee population suggesting that they might be beneficial in certain contexts and cannot be eliminated by natural selection. We have used a combination of enzymology, molecular biology and metabolomics to characterise the catalytic properties of honey bee LAM (AmLAM) and then used an indolizidine alkaloid swainsonine to inhibit its activity in vitro and in vivo. We show that AmLAM is inhibited in vitro by swainsonine albeit at slightly higher concentrations than in other animals. Dietary exposure of growing larvae to swainsonine leads to pronounced metabolic changes affecting not only saccharides, but also amino acids, polyols and polyamines. Interestingly, the abundance of two fatty acids implicated in epigenetic regulation is significantly reduced in treated individuals. Additionally, swainsonie causes loco-like symptoms, increased mortality and a subtle decrease in the rate of larval growth resulting in a subsequent developmental delay in pupal metamorphosis. We consider our findings in the context of cellular LAM function, larval development, environmental toxicity and colony-level impacts. The observed developmental heterochrony in swainsonine-treated larvae with lower LAM activity offer a plausible explanation for the existence of epialleles with impaired LAM expression. Individuals carrying such epialleles provide an additional level of epigenetic diversity that could be beneficial for the functioning of a colony whereby more flexibility in timing of adult emergence might be useful for task allocation.

  19. Swainsonine-induced lysosomal storage disease in goats caused by the ingestion of Turbina cordata in Northeastern Brazil.

    Science.gov (United States)

    Dantas, A F M; Riet-Correa, F; Gardner, D R; Medeiros, R M T; Barros, S S; Anjos, B L; Lucena, R B

    2007-01-01

    A disease of the central nervous system in goats was observed in the municipalities of Juazeiro, Casa Nova and Curaça, state of Bahia, and Petrolina, state of Pernambuco, Northeastern Brazil. The disease was produced experimentally in two goats by the administration of dry Turbina cordata mixed with grain. Clinical signs were observed after the ingestion of 62 and 106 g/kg body weight in 28 and 54 days, respectively. The concentration of swainsonine in the plant varied from less than 0.001% to 0.14% (dry weight). Clinical signs of natural and experimental cases included difficulties in standing, ataxia, hypermetria, wide-based stance, intention tremors, spastic paresis mainly in the hind legs, nystagmus, abnormal postural reactions, head tilting, and falling. Diffuse vacuolation of neurons, epithelial cells of pancreas, thyroids, and renal tubules were observed on the histology. From the electron microscopy of Purkinje cells the vacuoles represented dilated lysosomes. These findings demonstrated that T. cordata causes an acquired glycoprotein lysosomal storage disease. The intoxication occurs at least in an area of 27,000 km2 causing severe losses in goats, and some farmers report the disease also in cattle.

  20. Boneless Pose Editing and Animation

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas; Hansen, Kristian Evers; Erleben, Kenny

    2007-01-01

    In this paper, we propose a pose editing and animation method for triangulated surfaces based on a user controlled partitioning of the model into deformable parts and rigid parts which are denoted handles. In our pose editing system, the user can sculpt a set of poses simply by transforming...... problem in order to obtain the interpolation weights. While the system can be used simply for building poses, it is also an animation system. The user can specify a path for a given constraint and the model is animated correspondingly....

  1. Problem posing reflections and applications

    CERN Document Server

    Brown, Stephen I

    2014-01-01

    As a result of the editors' collaborative teaching at Harvard in the late 1960s, they produced a ground-breaking work -- The Art Of Problem Posing -- which related problem posing strategies to the already popular activity of problem solving. It took the concept of problem posing and created strategies for engaging in that activity as a central theme in mathematics education. Based in part upon that work and also upon a number of articles by its authors, other members of the mathematics education community began to apply and expand upon their ideas. This collection of thirty readings is a tes

  2. Videometrics technology of flyers' pose

    Science.gov (United States)

    Hu, Xiaoli; Su, Xiuqin; Zhang, Sanxi; Liu, Biao; Zhou, Zhiqiang

    2015-10-01

    In this paper pose measurement refers to flying pose measurement of rigid body including the pitch angle, yaw angel and roll angle. Pose measurement is of vital importance for such items as weapons settings, fault analysis and optimation design. Pose measurement based on optical images has many merits such as intuitive and non-contacted, which is a main method to measure pose currently. According to the parameters used and principle of the algorithms, the existing methods of pose measurement based on optical images are classified systematically and comprehensively for the first time as following: the methods of one station un-using camera's inner parameters are divided into the feature length ratio method and the direct linear transformation(DLT )method, otherwise they are divided into the perspective n points(PNP)problem and the optical and radar integration method, the axes from planes intersection using two stations extensible to multistation, and model matching applied to one or more stations, and then they are comparatively analyzed .At last combined with practical applications such as one or more stations, have or no model and inner parameters used or unused, some selection and improvement of key points are given practically.

  3. Modernizing emergency alerts poses challenges

    OpenAIRE

    Center for Homeland Defense and Security

    2010-01-01

    Center for Homeland Defense and Security, OUT OF THE CLASSROOM Download the paper: Paper: IPAWS (Integrated Public Alert and Warning System)” Modernizing emergency alerts poses challenges Anthony Cox is interested in the next generation of emergency alert systems.Any television viewer...

  4. Refining Visually Detected Object poses

    DEFF Research Database (Denmark)

    Holm, Preben; Petersen, Henrik Gordon

    2010-01-01

    to the particular object and in order to handle the demand for flexibility, there is an increasing demand for avoiding such dedicated mechanical alignment systems. Rather, it would be desirable to automatically locate and grasp randomly placed objects from tables, conveyor belts or even bins with a high accuracy......Automated industrial assembly today require that the 3D position and orientation (hereafter ''pose`) of the objects to be assembled are known precisely. Today this precision is mostly established by a dedicated mechanical object alignment system. However, such systems are often dedicated...... that enables direct assembly. Conventional vision systems and laser triangulation systems can locate randomly placed known objects (with 3D CAD models available) with some accuracy, but not necessarily a good enough accuracy. In this paper, we present a novel method for refining the pose accuracy of an object...

  5. Human pose co-estimation and applications.

    Science.gov (United States)

    Eichner, Marcin; Ferrari, Vittorio

    2012-11-01

    Most existing techniques for articulated Human Pose Estimation (HPE)consider each person independently. Here we tackle the problem in a new setting,coined Human Pose Coestimation (PCE), where multiple people are in a common,but unknown pose. The task of PCE is to estimate their poses jointly and toproduce prototypes characterizing the shared pose. Since the poses of the individual people should be similar to the prototype, PCE has less freedom compared to estimating each pose independently, which simplifies the problem.We demonstrate our PCE technique on two applications. The first is estimating the pose of people performing the same activity synchronously, such as during aerobics, cheerleading, and dancing in a group. We show that PCE improves pose estimation accuracy over estimating each person independently. The second application is learning prototype poses characterizing a pose class directly from an image search engine queried by the class name (e.g., “lotus pose”). We show that PCE leads to better pose estimation in such images, and it learns meaningful prototypes which can be used as priors for pose estimation in novel images.

  6. Problem Posing with the Multiplication Table

    Science.gov (United States)

    Dickman, Benjamin

    2014-01-01

    Mathematical problem posing is an important skill for teachers of mathematics, and relates readily to mathematical creativity. This article gives a bit of background information on mathematical problem posing, lists further references to connect problem posing and creativity, and then provides 20 problems based on the multiplication table to be…

  7. Pengenalan Pose Tangan Menggunakan HuMoment

    Directory of Open Access Journals (Sweden)

    Dina Budhi Utami

    2017-02-01

    Full Text Available Computer vision yang didasarkan pada pengenalan bentuk memiliki banyak potensi dalam interaksi manusia dan komputer. Pose tangan dapat dijadikan simbol interaksi manusia dengan komputer seperti halnya pada penggunaan berbagai pose tangan pada bahasa isyarat. Berbagai pose tangan dapat digunakan untuk menggantikan fungsi mouse, untuk mengendalikan robot, dan sebagainya. Penelitian ini difokuskan pada pembangunan sistem pengenalan pose tangan menggunakan HuMoment. Proses pengenalan pose tangan dimulai dengan melakukan segmentasi citra masukan untuk menghasilkan citra ROI (Region of Interest yaitu area telapak tangan. Selanjutnya dilakukan proses deteksi tepi. Kemudian dilakukan ekstraksi nilai HuMoment. Nilai HuMoment dikuantisasikan ke dalam bukukode yang dihasilkan dari proses pelatihan menggunakan K-Means. Proses kuantisasi dilakukan dengan menghitung nilai Euclidean Distance terkecil antara nilai HuMomment citra masukan dan bukukode. Berdasarkan hasil penelitian, nilai akurasi sistem dalam mengenali pose tangan adalah 88.57%.

  8. Head Pose Estimation from Passive Stereo Images

    DEFF Research Database (Denmark)

    Breitenstein, Michael D.; Jensen, Jeppe; Høilund, Carsten

    2009-01-01

    We present an algorithm to estimate the 3D pose (location and orientation) of a previously unseen face from low-quality range images. The algorithm generates many pose candidates from a signature to find the nose tip based on local shape, and then evaluates each candidate by computing an error fu...

  9. Learning toward practical head pose estimation

    Science.gov (United States)

    Sang, Gaoli; He, Feixiang; Zhu, Rong; Xuan, Shibin

    2017-08-01

    Head pose is useful information for many face-related tasks, such as face recognition, behavior analysis, human-computer interfaces, etc. Existing head pose estimation methods usually assume that the face images have been well aligned or that sufficient and precise training data are available. In practical applications, however, these assumptions are very likely to be invalid. This paper first investigates the impact of the failure of these assumptions, i.e., misalignment of face images, uncertainty and undersampling of training data, on head pose estimation accuracy of state-of-the-art methods. A learning-based approach is then designed to enhance the robustness of head pose estimation to these factors. To cope with misalignment, instead of using hand-crafted features, it seeks suitable features by learning from a set of training data with a deep convolutional neural network (DCNN), such that the training data can be best classified into the correct head pose categories. To handle uncertainty and undersampling, it employs multivariate labeling distributions (MLDs) with dense sampling intervals to represent the head pose attributes of face images. The correlation between the features and the dense MLD representations of face images is approximated by a maximum entropy model, whose parameters are optimized on the given training data. To estimate the head pose of a face image, its MLD representation is first computed according to the model based on the features extracted from the image by the trained DCNN, and its head pose is then assumed to be the one corresponding to the peak in its MLD. Evaluation experiments on the Pointing'04, FacePix, Multi-PIE, and CASIA-PEAL databases prove the effectiveness and efficiency of the proposed method.

  10. Students’ Creativity: Problem Posing in Structured Situation

    Science.gov (United States)

    Amalina, I. K.; Amirudin, M.; Budiarto, M. T.

    2018-01-01

    This is a qualitative research concerning on students’ creativity on problem posing task. The study aimed at describing the students’ creative thinking ability to pose the mathematics problem in structured situations with varied condition of given problems. In order to find out the students’ creative thinking ability, an analysis of mathematics problem posing test based on fluency, novelty, and flexibility and interview was applied for categorizing students’ responses on that task. The data analysis used the quality of problem posing and categorized in 4 level of creativity. The results revealed from 29 secondary students grade 8, a student in CTL (Creative Thinking Level) 1 met the fluency. A student in CTL 2 met the novelty, while a student in CTL 3 met both fluency and novelty and no one in CTL 4. These results are affected by students’ mathematical experience. The findings of this study highlight that student’s problem posing creativity are dependent on their experience in mathematics learning and from the point of view of which students start to pose problem.

  11. An improved silhouette for human pose estimation

    Science.gov (United States)

    Hawes, Anthony H.; Iftekharuddin, Khan M.

    2017-08-01

    We propose a novel method for analyzing images that exploits the natural lines of a human poses to find areas where self-occlusion could be present. Errors caused by self-occlusion cause several modern human pose estimation methods to mis-identify body parts, which reduces the performance of most action recognition algorithms. Our method is motivated by the observation that, in several cases, occlusion can be reasoned using only boundary lines of limbs. An intelligent edge detection algorithm based on the above principle could be used to augment the silhouette with information useful for pose estimation algorithms and push forward progress on occlusion handling for human action recognition. The algorithm described is applicable to computer vision scenarios involving 2D images and (appropriated flattened) 3D images.

  12. Factoring Algebraic Error for Relative Pose Estimation

    Energy Technology Data Exchange (ETDEWEB)

    Lindstrom, P; Duchaineau, M

    2009-03-09

    We address the problem of estimating the relative pose, i.e. translation and rotation, of two calibrated cameras from image point correspondences. Our approach is to factor the nonlinear algebraic pose error functional into translational and rotational components, and to optimize translation and rotation independently. This factorization admits subproblems that can be solved using direct methods with practical guarantees on global optimality. That is, for a given translation, the corresponding optimal rotation can directly be determined, and vice versa. We show that these subproblems are equivalent to computing the least eigenvector of second- and fourth-order symmetric tensors. When neither translation or rotation is known, alternating translation and rotation optimization leads to a simple, efficient, and robust algorithm for pose estimation that improves on the well-known 5- and 8-point methods.

  13. Yoga Poses Increase Subjective Energy and State Self-Esteem in Comparison to 'Power Poses'.

    Science.gov (United States)

    Golec de Zavala, Agnieszka; Lantos, Dorottya; Bowden, Deborah

    2017-01-01

    Research on beneficial consequences of yoga focuses on the effects of yogic breathing and meditation. Less is known about the psychological effects of performing yoga postures. The present study investigated the effects of yoga poses on subjective sense of energy and self-esteem. The effects of yoga postures were compared to the effects of 'power poses,' which arguably increase the sense of power and self-confidence due to their association with interpersonal dominance (Carney et al., 2010). The study tested the novel prediction that yoga poses, which are not associated with interpersonal dominance but increase bodily energy, would increase the subjective feeling of energy and therefore increase self-esteem compared to 'high power' and 'low power' poses. A two factorial, between participants design was employed. Participants performed either two standing yoga poses with open front of the body (n = 19), two standing yoga poses with covered front of the body (n = 22), two expansive, high power poses (n = 21), or two constrictive, low power poses (n = 20) for 1-min each. The results showed that yoga poses in comparison to 'power poses' increased self-esteem. This effect was mediated by an increased subjective sense of energy and was observed when baseline trait self-esteem was controlled for. These results suggest that the effects of performing open, expansive body postures may be driven by processes other than the poses' association with interpersonal power and dominance. This study demonstrates that positive effects of yoga practice can occur after performing yoga poses for only 2 min.

  14. Non-standard and improperly posed problems

    CERN Document Server

    Straughan, Brian; Ames, William F

    1997-01-01

    Written by two international experts in the field, this book is the first unified survey of the advances made in the last 15 years on key non-standard and improperly posed problems for partial differential equations.This reference for mathematicians, scientists, and engineers provides an overview of the methodology typically used to study improperly posed problems. It focuses on structural stability--the continuous dependence of solutions on the initial conditions and the modeling equations--and on problems for which data are only prescribed on part of the boundary.The book addresses continuou

  15. Ill-posed equations with transformed argument

    Directory of Open Access Journals (Sweden)

    Simone Gramsch

    2003-01-01

    Full Text Available We discuss the operator transforming the argument of a function in the L2-setting. Here this operator is unbounded and closed. For the approximate solution of ill-posed equations with closed operators, we present a new view on the Tikhonov regularization.

  16. Blink detection robust to various facial poses.

    Science.gov (United States)

    Lee, Won Oh; Lee, Eui Chul; Park, Kang Ryoung

    2010-11-30

    Applications based on eye-blink detection have increased, as a result of which it is essential for eye-blink detection to be robust and non-intrusive irrespective of the changes in the user's facial pose. However, most previous studies on camera-based blink detection have the disadvantage that their performances were affected by the facial pose. They also focused on blink detection using only frontal facial images. To overcome these disadvantages, we developed a new method for blink detection, which maintains its accuracy despite changes in the facial pose of the subject. This research is novel in the following four ways. First, the face and eye regions are detected by using both the AdaBoost face detector and a Lucas-Kanade-Tomasi (LKT)-based method, in order to achieve robustness to facial pose. Secondly, the determination of the state of the eye (being open or closed), needed for blink detection, is based on two features: the ratio of height to width of the eye region in a still image, and the cumulative difference of the number of black pixels of the eye region using an adaptive threshold in successive images. These two features are robustly extracted irrespective of the lighting variations by using illumination normalization. Thirdly, the accuracy of determining the eye state - open or closed - is increased by combining the above two features on the basis of the support vector machine (SVM). Finally, the SVM classifier for determining the eye state is adaptively selected according to the facial rotation. Experimental results using various databases showed that the blink detection by the proposed method is robust to various facial poses. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Pose Sentences: A new representation for action recognition using sequence of pose words

    NARCIS (Netherlands)

    Hatun, Kardelen; Duygulu, Pinar

    2008-01-01

    We propose a method for recognizing human actions in videos. Inspired from the recent bag-of-words approaches, we represent actions as documents consisting of words, where a word refers to the pose in a frame. Histogram of oriented gradients (HOG) features are used to describe poses, which are then

  18. Pre-Service Teachers' Free and Structured Mathematical Problem Posing

    Science.gov (United States)

    Silber, Steven; Cai, Jinfa

    2017-01-01

    This exploratory study examined how pre-service teachers (PSTs) pose mathematical problems for free and structured mathematical problem-posing conditions. It was hypothesized that PSTs would pose more complex mathematical problems under structured posing conditions, with increasing levels of complexity, than PSTs would pose under free posing…

  19. Quadratic optimization in ill-posed problems

    Science.gov (United States)

    Ben Belgacem, F.; Kaber, S.-M.

    2008-10-01

    Ill-posed quadratic optimization frequently occurs in control and inverse problems and is not covered by the Lax-Milgram-Riesz theory. Typically, small changes in the input data can produce very large oscillations on the output. We investigate the conditions under which the minimum value of the cost function is finite and we explore the 'hidden connection' between the optimization problem and the least-squares method. Eventually, we address some examples coming from optimal control and data completion, showing how relevant our contribution is in the knowledge of what happens for various ill-posed problems. The results we state bring a substantial improvement to the analysis of the regularization methods applied to the ill-posed quadratic optimization problems. Indeed, for the cost quadratic functions bounded from below the Lavrentiev method is just the Tikhonov regularization for the 'hidden least-squares' problem. As a straightforward result, Lavrentiev's regularization exhibits better regularization and convergence results than expected at first glance.

  20. Roll Back Mycotoxicosis: An Ethnobotanical Alternative | Duru ...

    African Journals Online (AJOL)

    Aqueous and cold absolute ethanolic extracts of the two plants were separately sprinkled on seed samples of Arachis hypogea (Papilionaceae), Irvingia gabonensis, (Irvingiaceae), Physeolus lunatus ... After 14 days of incubation, both pairs of sets recorded zero growth relative to the control which showed luxuriant growth.

  1. Robotic-surgical instrument wrist pose estimation.

    Science.gov (United States)

    Fabel, Stephan; Baek, Kyungim; Berkelman, Peter

    2010-01-01

    The Compact Lightweight Surgery Robot from the University of Hawaii includes two teleoperated instruments and one endoscope manipulator which act in accord to perform assisted interventional medicine. The relative positions and orientations of the robotic instruments and endoscope must be known to the teleoperation system so that the directions of the instrument motions can be controlled to correspond closely to the directions of the motions of the master manipulators, as seen by the the endoscope and displayed to the surgeon. If the manipulator bases are mounted in known locations and all manipulator joint variables are known, then the necessary coordinate transformations between the master and slave manipulators can be easily computed. The versatility and ease of use of the system can be increased, however, by allowing the endoscope or instrument manipulator bases to be moved to arbitrary positions and orientations without reinitializing each manipulator or remeasuring their relative positions. The aim of this work is to find the pose of the instrument end effectors using the video image from the endoscope camera. The P3P pose estimation algorithm is used with a Levenberg-Marquardt optimization to ensure convergence. The correct transformations between the master and slave coordinate frames can then be calculated and updated when the bases of the endoscope or instrument manipulators are moved to new, unknown, positions at any time before or during surgical procedures.

  2. Full Body Pose Estimation During Occlusion using Multiple Cameras

    DEFF Research Database (Denmark)

    Fihl, Preben; Cosar, Serhan

    Automatic estimation of the human pose enables many interesting applications and has therefore achieved much attention in recent years. One of the most successful approaches for estimating unconstrained poses has been the pictorial structures framework. However, occlusions between interacting...

  3. 2D Methods for pose invariant face recognition

    CSIR Research Space (South Africa)

    Mokoena, Ntabiseng

    2016-12-01

    Full Text Available The ability to recognise face images under random pose is a task that is done effortlessly by human beings. However, for a computer system, recognising face images under varying poses still remains an open research area. Face recognition across pose...

  4. Human action recognition based on estimated weak poses

    Science.gov (United States)

    Gong, Wenjuan; Gonzàlez, Jordi; Roca, Francesc Xavier

    2012-12-01

    We present a novel method for human action recognition (HAR) based on estimated poses from image sequences. We use 3D human pose data as additional information and propose a compact human pose representation, called a weak pose, in a low-dimensional space while still keeping the most discriminative information for a given pose. With predicted poses from image features, we map the problem from image feature space to pose space, where a Bag of Poses (BOP) model is learned for the final goal of HAR. The BOP model is a modified version of the classical bag of words pipeline by building the vocabulary based on the most representative weak poses for a given action. Compared with the standard k-means clustering, our vocabulary selection criteria is proven to be more efficient and robust against the inherent challenges of action recognition. Moreover, since for action recognition the ordering of the poses is discriminative, the BOP model incorporates temporal information: in essence, groups of consecutive poses are considered together when computing the vocabulary and assignment. We tested our method on two well-known datasets: HumanEva and IXMAS, to demonstrate that weak poses aid to improve action recognition accuracies. The proposed method is scene-independent and is comparable with the state-of-art method.

  5. To Strike a Pose: No Stereotype Backlash for Power Posing Women.

    Science.gov (United States)

    Rennung, Miriam; Blum, Johannes; Göritz, Anja S

    2016-01-01

    Power posing, the adoption of open and powerful postures, has effects that parallel those of actual social power. This study explored the social evaluation of adopting powerful vs. powerless body postures in men and women regarding perceived warmth, competence, and the likelihood of eliciting admiration, envy, pity, and contempt. Previous findings suggest that the display of power by women may have side effects due to gender stereotyping, namely reduced warmth ratings and negative emotional reactions. An experiment (N = 2,473) asked participants to rate pictures of men and women who adopted high-power or low-power body postures. High-power posers were rated higher on competence, admiration, envy, and contempt compared to low-power posers, whereas the opposite was true for pity. There was no impact of power posing on perceived warmth. Contrary to expectations, the poser's gender did not moderate any of the effects. These findings suggest that non-verbal displays of power do influence fundamental dimensions of social perception and their accompanying emotional reactions but result in comparably positive and negative evaluations for both genders.

  6. To Strike a Pose: No Stereotype Backlash for Power Posing Women

    Directory of Open Access Journals (Sweden)

    Miriam Rennung

    2016-09-01

    Full Text Available Power posing, the adoption of open and powerful postures, has effects that parallel those of actual social power. This study explored the social evaluation of adopting powerful versus powerless body postures in men and women regarding perceived warmth, competence, and the likelihood of eliciting admiration, envy, pity, and contempt. Previous findings suggest that the display of power by women may have side effects due to gender stereotyping, namely reduced warmth ratings and negative emotional reactions. An experiment (N = 2,473 asked participants to rate pictures of men and women who adopted high-power or low-power body postures. High-power posers were rated higher on competence, admiration, envy, and contempt compared to low-power posers, whereas the opposite was true for pity. There was no impact of power posing on perceived warmth. Contrary to expectations, the poser’s gender did not moderate any of the effects. These findings suggest that nonverbal displays of power do influence fundamental dimensions of social perception and their accompanying emotional reactions but result in comparably positive and negative evaluations for both genders.

  7. Local Feature Learning for Face Recognition under Varying Poses

    DEFF Research Database (Denmark)

    Duan, Xiaodong; Tan, Zheng-Hua

    2015-01-01

    In this paper, we present a local feature learning method for face recognition to deal with varying poses. As opposed to the commonly used approaches of recovering frontal face images from profile views, the proposed method extracts the subject related part from a local feature by removing the pose...... related part in it on the basis of a pose feature. The method has a closed-form solution, hence being time efficient. For performance evaluation, cross pose face recognition experiments are conducted on two public face recognition databases FERET and FEI. The proposed method shows a significant...... recognition improvement under varying poses over general local feature approaches and outperforms or is comparable with related state-of-the-art pose invariant face recognition approaches. Copyright ©2015 by IEEE....

  8. Head pose estimation algorithm based on deep learning

    Science.gov (United States)

    Cao, Yuanming; Liu, Yijun

    2017-05-01

    Head pose estimation has been widely used in the field of artificial intelligence, pattern recognition and intelligent human-computer interaction and so on. Good head pose estimation algorithm should deal with light, noise, identity, shelter and other factors robustly, but so far how to improve the accuracy and robustness of attitude estimation remains a major challenge in the field of computer vision. A method based on deep learning for pose estimation is presented. Deep learning with a strong learning ability, it can extract high-level image features of the input image by through a series of non-linear operation, then classifying the input image using the extracted feature. Such characteristics have greater differences in pose, while they are robust of light, identity, occlusion and other factors. The proposed head pose estimation is evaluated on the CAS-PEAL data set. Experimental results show that this method is effective to improve the accuracy of pose estimation.

  9. Pose-Normalized Image Generation for Person Re-identification

    OpenAIRE

    Qian, Xuelin; Fu, Yanwei; Wang, Wenxuan; Xiang, Tao; Wu, Yang; Jiang, Yu-Gang; Xue, Xiangyang

    2017-01-01

    Person Re-identification (re-id) faces two major challenges: the lack of cross-view paired training data and learning discriminative identity-sensitive and view-invariant features in the presence of large pose variations. In this work, we address both problems by proposing a novel deep person image generation model for synthesizing realistic person images conditional on pose. The model is based on a generative adversarial network (GAN) and used specifically for pose normalization in re-id, th...

  10. The lighter side of advertising: investigating posing and lighting biases.

    Science.gov (United States)

    Thomas, Nicole A; Burkitt, Jennifer A; Patrick, Regan E; Elias, Lorin J

    2008-11-01

    People tend to display the left cheek when posing for a portrait; however, this effect does not appear to generalise to advertising. The amount of body visible in the image and the sex of the poser might also contribute to the posing bias. Portraits also exhibit lateral lighting biases, with most images being lit from the left. This effect might also be present in advertisements. A total of 2801 full-page advertisements were sampled and coded for posing direction, lighting direction, sex of model, and amount of body showing. Images of females showed an overall leftward posing bias, but the biases in males depended on the amount of body visible. Males demonstrated rightward posing biases for head-only images. Overall, images tended to be lit from the top left corner. The two factors of posing and lighting biases appear to influence one another. Leftward-lit images had more leftward poses than rightward, while the opposite occurred for rightward-lit images. Collectively, these results demonstrate that the posing biases in advertisements are dependent on the amount of body showing in the image, and that biases in lighting direction interact with these posing biases.

  11. Helping Young Students to Better Pose an Environmental Problem

    Science.gov (United States)

    Pruneau, Diane; Freiman, Viktor; Barbier, Pierre-Yves; Langis, Joanne

    2009-01-01

    Grade 3 students were asked to solve a sedimentation problem in a local river. With scientists, students explored many aspects of the problem and proposed solutions. Graphic representation tools were used to help students to better pose the problem. Using questionnaires and interviews, researchers observed students' capacity to pose the problem…

  12. Posing Problems to Understand Children's Learning of Fractions

    Science.gov (United States)

    Cheng, Lu Pien

    2013-01-01

    In this study, ways in which problem posing activities aid our understanding of children's learning of addition of unlike fractions and product of proper fractions was examined. In particular, how a simple problem posing activity helps teachers take a second, deeper look at children's understanding of fraction concepts will be discussed. The…

  13. Motor biases do not influence posing orientation in selfies.

    Science.gov (United States)

    Lindell, Annukka K

    2017-01-01

    When posing for portraits people tend to offer their left cheek. This bias is also evident in selfies: informal photographic self-portraits taken with a smartphone. Mechanical biases have been argued to influence selfie posing orientation (predicting that using the left hand favours a stronger left cheek bias), however this hypothesis has not been directly tested. The present study was thus designed to determine whether motor biases influence selfie pose orientation. Three hundred and twenty participants (F = 159, M = 161) were asked to pose for a selfie "as you really are," and completed a handedness measure; hand used to take the selfie and selfie pose orientation were recorded. Ordinal logistic regression confirmed that neither participant handedness nor hand used to capture the selfie predicted selfie pose orientation. Regardless of sex, handedness, or hand used, participants were more likely to present a midline (49.75%) than a left (26.53%) or right (26.72%) cheek pose. Though handedness was a strong predictor of hand used to capture the selfie (left handers favour the left, and right handers the right, hand), it did not predict posing orientation. These results confirm that selfie cheek biases are not simply a residual effect of the mechanics of taking selfies.

  14. Formulas in inverse and ill-posed problems

    CERN Document Server

    Anikonov, Yu E

    1997-01-01

    The Inverse and Ill-Posed Problems Series is a series of monographs publishing postgraduate level information on inverse and ill-posed problems for an international readership of professional scientists and researchers. The series aims to publish works which involve both theory and applications in, e.g., physics, medicine, geophysics, acoustics, electrodynamics, tomography, and ecology.

  15. Eyes Do Not Lie: Spontaneous Versus Posed Smiles

    NARCIS (Netherlands)

    Dibeklioğlu, H.; Valenti, R.; Salah, A.A.; Gevers, T.

    2010-01-01

    Automatic detection of spontaneous versus posed facial expressions received a lot of attention in recent years. However, almost all published work in this area use complex facial features or multiple modalities, such as head pose and body movements with facial features. Besides, the results of these

  16. Non-well-posed infinite-dimensional linear systems

    NARCIS (Netherlands)

    Opmeer, Mark R.; Curtain, Ruth F.

    2006-01-01

    We provide an abstract framework for infinite-dimensional linear systems that are not necessarily well-posed in the standard L2 sense. One example of a system that is not well-posed but does fit into the new abstract framework is the heat equation with Dirichlet control and Neumann observation. The

  17. Estimating 2D Upper Body Poses from Monocular Images

    NARCIS (Netherlands)

    Broekhuijsen, Jeroen; Poppe, Ronald Walter; Poel, Mannes

    2006-01-01

    Automatic estimation and recognition of poses from video allows for a whole range of applications. The research described here is an important step towards automatic extraction of 3D poses. We describe our research to extract the 2D joint locations of the people in meeting videos. The key point of

  18. Face pose tracking using the four-point algorithm

    Science.gov (United States)

    Fung, Ho Yin; Wong, Kin Hong; Yu, Ying Kin; Tsui, Kwan Pang; Kam, Ho Chuen

    2017-06-01

    In this paper, we have developed an algorithm to track the pose of a human face robustly and efficiently. Face pose estimation is very useful in many applications such as building virtual reality systems and creating an alternative input method for the disabled. Firstly, we have modified a face detection toolbox called DLib for the detection of a face in front of a camera. The detected face features are passed to a pose estimation method, known as the four-point algorithm, for pose computation. The theory applied and the technical problems encountered during system development are discussed in the paper. It is demonstrated that the system is able to track the pose of a face in real time using a consumer grade laptop computer.

  19. Person-Independent Head Pose Estimation Using Biased Manifold Embedding

    Directory of Open Access Journals (Sweden)

    Sethuraman Panchanathan

    2008-02-01

    Full Text Available Head pose estimation has been an integral problem in the study of face recognition systems and human-computer interfaces, as part of biometric applications. A fine estimate of the head pose angle is necessary and useful for several face analysis applications. To determine the head pose, face images with varying pose angles can be considered to be lying on a smooth low-dimensional manifold in high-dimensional image feature space. However, when there are face images of multiple individuals with varying pose angles, manifold learning techniques often do not give accurate results. In this work, we propose a framework for a supervised form of manifold learning called Biased Manifold Embedding to obtain improved performance in head pose angle estimation. This framework goes beyond pose estimation, and can be applied to all regression applications. This framework, although formulated for a regression scenario, unifies other supervised approaches to manifold learning that have been proposed so far. Detailed studies of the proposed method are carried out on the FacePix database, which contains 181 face images each of 30 individuals with pose angle variations at a granularity of 1∘. Since biometric applications in the real world may not contain this level of granularity in training data, an analysis of the methodology is performed on sparsely sampled data to validate its effectiveness. We obtained up to 2∘ average pose angle estimation error in the results from our experiments, which matched the best results obtained for head pose estimation using related approaches.

  20. ESPRIT: Exercise Sensing and Pose Recovery Inference Tool Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop ESPRIT: an Exercise Sensing and Pose Recovery Inference Tool, in support of NASA's effort in developing crew exercise technologies for...

  1. RELATIVE CAMERA POSE ESTIMATION METHOD USING OPTIMIZATION ON THE MANIFOLD

    Directory of Open Access Journals (Sweden)

    C. Cheng

    2017-05-01

    Full Text Available To solve the problem of relative camera pose estimation, a method using optimization with respect to the manifold is proposed. Firstly from maximum-a-posteriori (MAP model to nonlinear least squares (NLS model, the general state estimation model using optimization is derived. Then the camera pose estimation model is applied to the general state estimation model, while the parameterization of rigid body transformation is represented by Lie group/algebra. The jacobian of point-pose model with respect to Lie group/algebra is derived in detail and thus the optimization model of rigid body transformation is established. Experimental results show that compared with the original algorithms, the approaches with optimization can obtain higher accuracy both in rotation and translation, while avoiding the singularity of Euler angle parameterization of rotation. Thus the proposed method can estimate relative camera pose with high accuracy and robustness.

  2. Health Issues: Do Cell Phones Pose a Health Hazard?

    Science.gov (United States)

    ... Procedures Home, Business, and Entertainment Products Cell Phones Health Issues Share Tweet Linkedin Pin it More sharing ... it Email Print Do cell phones pose a health hazard? Many people are concerned that cell phone ...

  3. Mathematical Thinking and Creativity through Mathematical Problem Posing and Solving

    Directory of Open Access Journals (Sweden)

    María F. Ayllón

    2016-04-01

    Full Text Available This work shows the relationship between the development of mathematical thinking and creativity with mathematical problem posing and solving. Creativity and mathematics are disciplines that do not usually appear together. Both concepts constitute complex processes sharing elements, such as fluency (number of ideas, flexibility (range of ideas, novelty (unique idea and elaboration (idea development. These factors contribute, among others, to the fact that schoolchildren are competent in mathematics. The problem solving and posing are a very powerful evaluation tool that shows the mathematical reasoning and creative level of a person. Creativity is part of the mathematics education and is a necessary ingredient to perform mathematical assignments. This contribution presents some important research works about problem posing and solving related to the development of mathematical knowledge and creativity. To that end, it is based on various beliefs reflected in the literature with respect to notions of creativity, problem solving and posing.

  4. Inverse and Ill-posed Problems Theory and Applications

    CERN Document Server

    Kabanikhin, S I

    2011-01-01

    The text demonstrates the methods for proving the existence (if et all) and finding of inverse and ill-posed problems solutions in linear algebra, integral and operator equations, integral geometry, spectral inverse problems, and inverse scattering problems. It is given comprehensive background material for linear ill-posed problems and for coefficient inverse problems for hyperbolic, parabolic, and elliptic equations. A lot of examples for inverse problems from physics, geophysics, biology, medicine, and other areas of application of mathematics are included.

  5. UAV to UAV Target Detection and Pose Estimation

    Science.gov (United States)

    2012-06-01

    open computer vision) for real-time implementation and faster computation since OpenCV has precompiled libraries that may work better for real image...affordable CCD cameras and open coding libraries . We accomplish this by reviewing past literature about UAV detection and pose estimation and exploring...capabilities suitable for the purpose of UAV to UAV detection and pose estima- tion using affordable CCD cameras and open coding libraries . We

  6. Joint albedo estimation and pose tracking from video.

    Science.gov (United States)

    Taheri, Sima; Sankaranarayanan, Aswin C; Chellappa, Rama

    2013-07-01

    The albedo of a Lambertian object is a surface property that contributes to an object's appearance under changing illumination. As a signature independent of illumination, the albedo is useful for object recognition. Single image-based albedo estimation algorithms suffer due to shadows and non-Lambertian effects of the image. In this paper, we propose a sequential algorithm to estimate the albedo from a sequence of images of a known 3D object in varying poses and illumination conditions. We first show that by knowing/estimating the pose of the object at each frame of a sequence, the object's albedo can be efficiently estimated using a Kalman filter. We then extend this for the case of unknown pose by simultaneously tracking the pose as well as updating the albedo through a Rao-Blackwellized particle filter (RBPF). More specifically, the albedo is marginalized from the posterior distribution and estimated analytically using the Kalman filter, while the pose parameters are estimated using importance sampling and by minimizing the projection error of the face onto its spherical harmonic subspace, which results in an illumination-insensitive pose tracking algorithm. Illustrations and experiments are provided to validate the effectiveness of the approach using various synthetic and real sequences followed by applications to unconstrained, video-based face recognition.

  7. Optimal accelerometer placement on a robot arm for pose estimation

    Science.gov (United States)

    Wijayasinghe, Indika B.; Sanford, Joseph D.; Abubakar, Shamsudeen; Saadatzi, Mohammad Nasser; Das, Sumit K.; Popa, Dan O.

    2017-05-01

    The performance of robots to carry out tasks depends in part on the sensor information they can utilize. Usually, robots are fitted with angle joint encoders that are used to estimate the position and orientation (or the pose) of its end-effector. However, there are numerous situations, such as in legged locomotion, mobile manipulation, or prosthetics, where such joint sensors may not be present at every, or any joint. In this paper we study the use of inertial sensors, in particular accelerometers, placed on the robot that can be used to estimate the robot pose. Studying accelerometer placement on a robot involves many parameters that affect the performance of the intended positioning task. Parameters such as the number of accelerometers, their size, geometric placement and Signal-to-Noise Ratio (SNR) are included in our study of their effects for robot pose estimation. Due to the ubiquitous availability of inexpensive accelerometers, we investigated pose estimation gains resulting from using increasingly large numbers of sensors. Monte-Carlo simulations are performed with a two-link robot arm to obtain the expected value of an estimation error metric for different accelerometer configurations, which are then compared for optimization. Results show that, with a fixed SNR model, the pose estimation error decreases with increasing number of accelerometers, whereas for a SNR model that scales inversely to the accelerometer footprint, the pose estimation error increases with the number of accelerometers. It is also shown that the optimal placement of the accelerometers depends on the method used for pose estimation. The findings suggest that an integration-based method favors placement of accelerometers at the extremities of the robot links, whereas a kinematic-constraints-based method favors a more uniformly distributed placement along the robot links.

  8. Pose estimation for augmented reality applications using genetic algorithm.

    Science.gov (United States)

    Yu, Ying Kin; Wong, Kin Hong; Chang, Michael Ming Yuen

    2005-12-01

    This paper describes a genetic algorithm that tackles the pose-estimation problem in computer vision. Our genetic algorithm can find the rotation and translation of an object accurately when the three-dimensional structure of the object is given. In our implementation, each chromosome encodes both the pose and the indexes to the selected point features of the object. Instead of only searching for the pose as in the existing work, our algorithm, at the same time, searches for a set containing the most reliable feature points in the process. This mismatch filtering strategy successfully makes the algorithm more robust under the presence of point mismatches and outliers in the images. Our algorithm has been tested with both synthetic and real data with good results. The accuracy of the recovered pose is compared to the existing algorithms. Our approach outperformed the Lowe's method and the other two genetic algorithms under the presence of point mismatches and outliers. In addition, it has been used to estimate the pose of a real object. It is shown that the proposed method is applicable to augmented reality applications.

  9. Human Pose Estimation from Monocular Images: A Comprehensive Survey

    Science.gov (United States)

    Gong, Wenjuan; Zhang, Xuena; Gonzàlez, Jordi; Sobral, Andrews; Bouwmans, Thierry; Tu, Changhe; Zahzah, El-hadi

    2016-01-01

    Human pose estimation refers to the estimation of the location of body parts and how they are connected in an image. Human pose estimation from monocular images has wide applications (e.g., image indexing). Several surveys on human pose estimation can be found in the literature, but they focus on a certain category; for example, model-based approaches or human motion analysis, etc. As far as we know, an overall review of this problem domain has yet to be provided. Furthermore, recent advancements based on deep learning have brought novel algorithms for this problem. In this paper, a comprehensive survey of human pose estimation from monocular images is carried out including milestone works and recent advancements. Based on one standard pipeline for the solution of computer vision problems, this survey splits the problem into several modules: feature extraction and description, human body models, and modeling methods. Problem modeling methods are approached based on two means of categorization in this survey. One way to categorize includes top-down and bottom-up methods, and another way includes generative and discriminative methods. Considering the fact that one direct application of human pose estimation is to provide initialization for automatic video surveillance, there are additional sections for motion-related methods in all modules: motion features, motion models, and motion-based methods. Finally, the paper also collects 26 publicly available data sets for validation and provides error measurement methods that are frequently used. PMID:27898003

  10. Students’ Mathematical Creative Thinking through Problem Posing Learning

    Science.gov (United States)

    Ulfah, U.; Prabawanto, S.; Jupri, A.

    2017-09-01

    The research aims to investigate the differences in enhancement of students’ mathematical creative thinking ability of those who received problem posing approach assisted by manipulative media and students who received problem posing approach without manipulative media. This study was a quasi experimental research with non-equivalent control group design. Population of this research was third-grade students of a primary school in Bandung city in 2016/2017 academic year. Sample of this research was two classes as experiment class and control class. The instrument used is a test of mathematical creative thinking ability. Based on the results of the research, it is known that the enhancement of the students’ mathematical creative thinking ability of those who received problem posing approach with manipulative media aid is higher than the ability of those who received problem posing approach without manipulative media aid. Students who get learning problem posing learning accustomed in arranging mathematical sentence become matter of story so it can facilitate students to comprehend about story

  11. Pose-Invariant Face Recognition via RGB-D Images

    Directory of Open Access Journals (Sweden)

    Gaoli Sang

    2016-01-01

    Full Text Available Three-dimensional (3D face models can intrinsically handle large pose face recognition problem. In this paper, we propose a novel pose-invariant face recognition method via RGB-D images. By employing depth, our method is able to handle self-occlusion and deformation, both of which are challenging problems in two-dimensional (2D face recognition. Texture images in the gallery can be rendered to the same view as the probe via depth. Meanwhile, depth is also used for similarity measure via frontalization and symmetric filling. Finally, both texture and depth contribute to the final identity estimation. Experiments on Bosphorus, CurtinFaces, Eurecom, and Kiwi databases demonstrate that the additional depth information has improved the performance of face recognition with large pose variations and under even more challenging conditions.

  12. A direct method for nonlinear ill-posed problems

    Science.gov (United States)

    Lakhal, A.

    2018-02-01

    We propose a direct method for solving nonlinear ill-posed problems in Banach-spaces. The method is based on a stable inversion formula we explicitly compute by applying techniques for analytic functions. Furthermore, we investigate the convergence and stability of the method and prove that the derived noniterative algorithm is a regularization. The inversion formula provides a systematic sensitivity analysis. The approach is applicable to a wide range of nonlinear ill-posed problems. We test the algorithm on a nonlinear problem of travel-time inversion in seismic tomography. Numerical results illustrate the robustness and efficiency of the algorithm.

  13. Present and potential security threats posed to civil aviation

    Directory of Open Access Journals (Sweden)

    Stanislav SZABO

    2012-06-01

    Full Text Available Aircraft presents ideal object for terrorist attack. Apart from the risks posed by possible terrorist attacks on airborne aircraft, air terrorism includes the threats to general aviation on the ground, including airports and surrounding infrastructure. Air oriented terrorism in all of its forms can undermine public confidence in the safety of air travel, which could result in negative effects for certain airlines and other firms in aviation industry due to decline in passenger travel and cargo shipment. This article is giving an overview about the redoubtable present and potential future threats posed to in-flight security, and possibilities and solutions how to mitigate the risks on acceptable level.

  14. Human pose recovery for rehabilitation using ambulatory sensors.

    Science.gov (United States)

    Lin, Jonathan Feng-Shun; Kulić, Dana

    2013-01-01

    In this paper, an approach for lower-leg pose recovery from ambulatory sensors is implemented and validated in a clinical setting. Inertial measurement units are attached to patients undergoing physiotherapy. The sensor data is combined with a kinematic model within an extended Kalman filter framework to perform joint angle estimation. Anthropometric joint limits and process noise adaptation are employed to improve the quality of the joint angle estimation. The proposed approach is tested on 7 patients following total hip or knee joint replacement surgery. The proposed approach achieves an average root-mean-square error of 0.12 radians at key poses.

  15. Problem Posing as Providing Students with Content-Specific Motives

    NARCIS (Netherlands)

    Klaassen, C.W.J.M.; Doorman, L.M.

    2015-01-01

    We interpret problem posing not as an end in itself, but as a means to add quality to students' process of learning content. Our basic tenet is that all along students know the purpose(s) of what they are doing. This condition is not easily and not often satisfied in education, as we illustrate with

  16. Mathematical Thinking and Creativity through Mathematical Problem Posing and Solving

    Science.gov (United States)

    Ayllón, María F.; Gómez, Isabel A.; Ballesta-Claver, Julio

    2016-01-01

    This work shows the relationship between the development of mathematical thinking and creativity with mathematical problem posing and solving. Creativity and mathematics are disciplines that do not usually appear together. Both concepts constitute complex processes sharing elements, such as fluency (number of ideas), flexibility (range of ideas),…

  17. Astronaut Linda Godwin poses with spacesuit she wore for launch

    Science.gov (United States)

    1994-01-01

    Astronaut Linda M. Godwin, STS-59 payload commander, poses with the spacesuit she wore for launch. She will eventually wear the partial pressure suit for the entry phase of the Space Shuttle Endeavour's week and a half mission in Earth orbit.

  18. Effects of pose and image resolution on automatic face recognition

    NARCIS (Netherlands)

    Mahmood, Zahid; Ali, Tauseef; Khan, Samee U.

    The popularity of face recognition systems have increased due to their use in widespread applications. Driven by the enormous number of potential application domains, several algorithms have been proposed for face recognition. Face pose and image resolutions are among the two important factors that

  19. A combinatorial study of pose effects in unfamiliar face recognition.

    Science.gov (United States)

    Van der Linde, Ian; Watson, Tamara

    2010-03-05

    The face inversion effect, evidence that humans possess a specialized system for face processing, and the (3/4) view advantage, evidence that a canonical viewpoint exists from which faces may be optimally recognized, are two commonly cited findings in the face processing literature. In this paper, the interaction of these effects is examined in a sequential matching paradigm in which unfamiliar faces are combinatorially randomized in pose across two dimensions (roll and yaw). Using large numbers of poses, trials and face stimuli, two experiments were conducted in which pose was either jointly or independently randomized between intervals. Results include that performance was modulated in a continuous fashion as each dimension was manipulated, that an offset-specific (3/4) advantage exists, that both specific study and test pose affect recognition, and that, for like offset, yaw rotation is more deleterious to performance than roll rotation. Response bias effects included that matched or reflective yaw led observers to employ a more liberal criterion.

  20. Pose Reconstruction of Flexible Instruments from Endoscopic Images using Markers

    NARCIS (Netherlands)

    Reilink, Rob; Stramigioli, Stefano; Misra, Sarthak

    2012-01-01

    A system is developed that can reconstruct the pose of flexible endoscopic instruments that are used in ad- vanced flexible endoscopes using solely the endoscopic images. Four markers are placed on the instrument, whose positions are measured in the image. These measurements are compared to a

  1. Lessons about Climate Change Pose Many Challenges for Science Teachers

    Science.gov (United States)

    Cavanagh, Sean

    2007-01-01

    This article reports on lessons about climate change which pose many challenges for science teachers. The natural world today offers a broad--and dire--catalog of scientific phenomena for teachers wanting to craft classroom lessons on the topic of climate change. As public concern about global warming increases, teachers are carving out a larger…

  2. Health and Environmental Hazards Posed by Urban Livestock ...

    African Journals Online (AJOL)

    Livestock's contribution to climate change is now an established fact and closeness of livestock to human beings in urban areas portends many health and environmental implications. The study ascertained farmer's perception of health and environmental hazards posed by livestock keeping in Enugu Urban, Nigeria and its ...

  3. Problem Posing with Realistic Mathematics Education Approach in Geometry Learning

    Science.gov (United States)

    Mahendra, R.; Slamet, I.; Budiyono

    2017-09-01

    One of the difficulties of students in the learning of geometry is on the subject of plane that requires students to understand the abstract matter. The aim of this research is to determine the effect of Problem Posing learning model with Realistic Mathematics Education Approach in geometry learning. This quasi experimental research was conducted in one of the junior high schools in Karanganyar, Indonesia. The sample was taken using stratified cluster random sampling technique. The results of this research indicate that the model of Problem Posing learning with Realistic Mathematics Education Approach can improve students’ conceptual understanding significantly in geometry learning especially on plane topics. It is because students on the application of Problem Posing with Realistic Mathematics Education Approach are become to be active in constructing their knowledge, proposing, and problem solving in realistic, so it easier for students to understand concepts and solve the problems. Therefore, the model of Problem Posing learning with Realistic Mathematics Education Approach is appropriately applied in mathematics learning especially on geometry material. Furthermore, the impact can improve student achievement.

  4. Enhancing Students' Communication Skills through Problem Posing and Presentation

    Science.gov (United States)

    Sugito; E. S., Sri Mulyani; Hartono; Supartono

    2017-01-01

    This study was to explore how enhance communication skill through problem posing and presentation method. The subjects of this research were the seven grade students Junior High School, including 20 male and 14 female. This research was conducted in two cycles and each cycle consisted of four steps, they were: planning, action, observation, and…

  5. Problem Posing Based on Investigation Activities by University Students

    Science.gov (United States)

    da Ponte, Joao Pedro; Henriques, Ana

    2013-01-01

    This paper reports a classroom-based study involving investigation activities in a university numerical analysis course. The study aims to analyse students' mathematical processes and to understand how these activities provide opportunities for problem posing. The investigations were intended to stimulate students in asking questions, to trigger…

  6. Optical neural network system for pose determination of spinning satellites

    Science.gov (United States)

    Lee, Andrew; Casasent, David

    1990-01-01

    An optical neural network architecture and algorithm based on a Hopfield optimization network are presented for multitarget tracking. This tracker utilizes a neuron for every possible target track, and a quadratic energy function of neural activities which is minimized using gradient descent neural evolution. The neural net tracker is demonstrated as part of a system for determining position and orientation (pose) of spinning satellites with respect to a robotic spacecraft. The input to the system is time sequence video from a single camera. Novelty detection and filtering are utilized to locate and segment novel regions from the input images. The neural net multitarget tracker determines the correspondences (or tracks) of the novel regions as a function of time, and hence the paths of object (satellite) parts. The path traced out by a given part or region is approximately elliptical in image space, and the position, shape and orientation of the ellipse are functions of the satellite geometry and its pose. Having a geometric model of the satellite, and the elliptical path of a part in image space, the three-dimensional pose of the satellite is determined. Digital simulation results using this algorithm are presented for various satellite poses and lighting conditions.

  7. 3D Facial Landmarking under Expression, Pose, and Occlusion Variations

    NARCIS (Netherlands)

    H. Dibeklioğ lu; A.A. Salah (Albert Ali); L. Akarun

    2008-01-01

    htmlabstractAutomatic localization of 3D facial features is important for face recognition, tracking, modeling and expression analysis. Methods developed for 2D images were shown to have problems working across databases acquired with different illumination conditions. Expression variations, pose

  8. Pose tracking for augmented reality applications in outdoor archaeological sites

    Science.gov (United States)

    Younes, Georges; Asmar, Daniel; Elhajj, Imad; Al-Harithy, Howayda

    2017-01-01

    In recent years, agencies around the world have invested huge amounts of effort toward digitizing many aspects of the world's cultural heritage. Of particular importance is the digitization of outdoor archaeological sites. In the spirit of valorization of this digital information, many groups have developed virtual or augmented reality (AR) computer applications themed around a particular archaeological object. The problem of pose tracking in outdoor AR applications is addressed. Different positional systems are analyzed, resulting in the selection of a monocular camera-based user tracker. The limitations that challenge this technique from map generation, scale, anchoring, to lighting conditions are analyzed and systematically addressed. Finally, as a case study, our pose tracking system is implemented within an AR experience in the Byblos Roman theater in Lebanon.

  9. Robust feature tracking for endoscopic pose estimation and structure recovery

    Science.gov (United States)

    Speidel, S.; Krappe, S.; Röhl, S.; Bodenstedt, S.; Müller-Stich, B.; Dillmann, R.

    2013-03-01

    Minimally invasive surgery is a highly complex medical discipline with several difficulties for the surgeon. To alleviate these difficulties, augmented reality can be used for intraoperative assistance. For visualization, the endoscope pose must be known which can be acquired with a SLAM (Simultaneous Localization and Mapping) approach using the endoscopic images. In this paper we focus on feature tracking for SLAM in minimally invasive surgery. Robust feature tracking and minimization of false correspondences is crucial for localizing the endoscope. As sensory input we use a stereo endoscope and evaluate different feature types in a developed SLAM framework. The accuracy of the endoscope pose estimation is validated with synthetic and ex vivo data. Furthermore we test the approach with in vivo image sequences from da Vinci interventions.

  10. A New Full Pose Measurement Method for Robot Calibration

    Directory of Open Access Journals (Sweden)

    Hee-Jun Kang

    2013-07-01

    Full Text Available Identification of robot kinematic errors during the calibration process often requires accurate full pose measurements (position and orientation of robot end-effectors in Cartesian space. This paper proposes a new method of full pose measurement of robot end-effectors for calibration. This method is based on an analysis of the features of a set of target points (placed on a rotating end-effector on a circular trajectory. The accurate measurement is validated by computational simulation results from the Puma robot. Moreover, experimental calibration and validation results for the Hyundai HA-06 robot prove the effectiveness, correctness, and reliability of the proposed method. This method can be applied to robots that have entirely revolute joints or to robots for which only the last joint is revolute.

  11. Quantifying the risk to life posed by hyperconcetrated flows

    OpenAIRE

    De Chiara, Giovanna

    2014-01-01

    2012-2013 In recent years, the disasters caused by landslides tragically increased due to the demographic growth and the indiscriminate use of land. Among the different types of landslides, flow-like phenomena - often simultaneously affecting large areas - are associated with the most catastrophic consequences in terms of loss of human life and economic damage. Understanding, forecasting and controlling the risk posed by flow-like phenomena are now recognised to be a priority for the sa...

  12. Robustifying Correspondence Based 6D Object Pose Estimation

    DEFF Research Database (Denmark)

    Hietanen, Antti; Halme, Jussi; Buch, Anders Glent

    2017-01-01

    We propose two methods to robustify point correspondence based 6D object pose estimation. The first method, curvature filtering, is based on the assumption that low curvature regions provide false matches, and removing points in these regions improves robustness. The second method, region pruning....... For the experiments, we evaluated three correspondence selection methods, Geometric Consistency (GC) [1], Hough Grouping (HG) [2] and Search of Inliers (SI) [3] and report systematic improvements for their robustified versions with two distinct datasets....

  13. Iterative regularization methods for nonlinear ill-posed problems

    CERN Document Server

    Scherzer, Otmar; Kaltenbacher, Barbara

    2008-01-01

    Nonlinear inverse problems appear in many applications, and typically they lead to mathematical models that are ill-posed, i.e., they are unstable under data perturbations. Those problems require a regularization, i.e., a special numerical treatment. This book presents regularization schemes which are based on iteration methods, e.g., nonlinear Landweber iteration, level set methods, multilevel methods and Newton type methods.

  14. A Comparison of Directional Distances for Hand Pose Estimation

    OpenAIRE

    Tzionas, Dimitrios; Gall, Juergen

    2017-01-01

    Benchmarking methods for 3d hand tracking is still an open problem due to the difficulty of acquiring ground truth data. We introduce a new dataset and benchmarking protocol that is insensitive to the accumulative error of other protocols. To this end, we create testing frame pairs of increasing difficulty and measure the pose estimation error separately for each of them. This approach gives new insights and allows to accurately study the performance of each feature or method without employin...

  15. Sensing Strategies for Disambiguating among Multiple Objects in Known Poses.

    Science.gov (United States)

    1985-08-01

    ELEMENT. PROIECT. TASK Artificial Inteligence Laboratory AE OKUI UBR 545 Technology Square Cambridge, MA 021.39 11. CONTROLLING OFFICE NAME AND ADDRESS 12...AD-Ali65 912 SENSING STRATEGIES FOR DISAMBIGURTING MONG MULTIPLE 1/1 OBJECTS IN KNOWN POSES(U) MASSACHUSETTS INST OF TECH CAMBRIDGE ARTIFICIAL ...or Dist Special 1 ’ MASSACHUSETTS INSTITUTE OF TECHNOLOGY ARTIFICIAL INTELLIGENCE LABORATORY A. I. Memo 855 August, 1985 Sensing Strategies for

  16. Teaching Human Poses Interactively to a Social Robot

    Science.gov (United States)

    Gonzalez-Pacheco, Victor; Malfaz, Maria; Fernandez, Fernando; Salichs, Miguel A.

    2013-01-01

    The main activity of social robots is to interact with people. In order to do that, the robot must be able to understand what the user is saying or doing. Typically, this capability consists of pre-programmed behaviors or is acquired through controlled learning processes, which are executed before the social interaction begins. This paper presents a software architecture that enables a robot to learn poses in a similar way as people do. That is, hearing its teacher's explanations and acquiring new knowledge in real time. The architecture leans on two main components: an RGB-D (Red-, Green-, Blue- Depth) -based visual system, which gathers the user examples, and an Automatic Speech Recognition (ASR) system, which processes the speech describing those examples. The robot is able to naturally learn the poses the teacher is showing to it by maintaining a natural interaction with the teacher. We evaluate our system with 24 users who teach the robot a predetermined set of poses. The experimental results show that, with a few training examples, the system reaches high accuracy and robustness. This method shows how to combine data from the visual and auditory systems for the acquisition of new knowledge in a natural manner. Such a natural way of training enables robots to learn from users, even if they are not experts in robotics. PMID:24048336

  17. Teaching Human Poses Interactively to a Social Robot

    Directory of Open Access Journals (Sweden)

    Miguel A. Salichs

    2013-09-01

    Full Text Available The main activity of social robots is to interact with people. In order to do that, the robot must be able to understand what the user is saying or doing. Typically, this capability consists of pre-programmed behaviors or is acquired through controlled learning processes, which are executed before the social interaction begins. This paper presents a software architecture that enables a robot to learn poses in a similar way as people do. That is, hearing its teacher’s explanations and acquiring new knowledge in real time. The architecture leans on two main components: an RGB-D (Red-, Green-, Blue- Depth -based visual system, which gathers the user examples, and an Automatic Speech Recognition (ASR system, which processes the speech describing those examples. The robot is able to naturally learn the poses the teacher is showing to it by maintaining a natural interaction with the teacher. We evaluate our system with 24 users who teach the robot a predetermined set of poses. The experimental results show that, with a few training examples, the system reaches high accuracy and robustness. This method shows how to combine data from the visual and auditory systems for the acquisition of new knowledge in a natural manner. Such a natural way of training enables robots to learn from users, even if they are not experts in robotics.

  18. Shape recognition and pose estimation for mobile Augmented Reality.

    Science.gov (United States)

    Hagbi, Nate; Bergig, Oriel; El-Sana, Jihad; Billinghurst, Mark

    2011-10-01

    Nestor is a real-time recognition and camera pose estimation system for planar shapes. The system allows shapes that carry contextual meanings for humans to be used as Augmented Reality (AR) tracking targets. The user can teach the system new shapes in real time. New shapes can be shown to the system frontally, or they can be automatically rectified according to previously learned shapes. Shapes can be automatically assigned virtual content by classification according to a shape class library. Nestor performs shape recognition by analyzing contour structures and generating projective-invariant signatures from their concavities. The concavities are further used to extract features for pose estimation and tracking. Pose refinement is carried out by minimizing the reprojection error between sample points on each image contour and its library counterpart. Sample points are matched by evolving an active contour in real time. Our experiments show that the system provides stable and accurate registration, and runs at interactive frame rates on a Nokia N95 mobile phone. © 2011 IEEE

  19. Visual measurement system for roadheaders pose detection in mines

    Science.gov (United States)

    Du, Yuxin; Tong, Minming; Liu, Ting; Dong, Haibo

    2016-10-01

    To satisfy the demand for automatic roadway drivage in mines, a real-time body pose detection system is proposed for the mine-used boom-type roadheader. Utilizing cross lasers and laser targets as information sources, this system first establishes a mathematical model to describe the machine position in space and realizes the precise localization of reference points on targets via the improved Retinex adaptive image enhancement algorithm and maximum wavelet transform module algorithm. It then sets up the machine body position calculating model and makes use of the space matrix transformation method to obtain the yaw, pitch, roll angles, and horizontal and vertical deviations of the roadheader, finally fulfilling the automatic machine pose detection in real time. Based on the preceding theoretical analysis, an experimental platform is built up in laboratory conditions for the purpose of simulating pose changes of the machine inside the tunnel and automatically detecting its position. The experimental results show that the measurement accuracy of angles is within 0.16 deg and the detection precision of displacements is higher than 10 mm, which can satisfy requirements of automatic, precise, and real-time positioning for the roadheader during the process of tunnel construction.

  20. LEVELING STUDENTS’ CREATIVE THINKING IN SOLVING AND POSING MATHEMATICAL PROBLEM

    Directory of Open Access Journals (Sweden)

    Tatag Yuli Eko Siswono

    2010-07-01

    Full Text Available Many researchers assume that people are creative, but their degree ofcreativity is different. The notion of creative thinking level has beendiscussed .by experts. The perspective of mathematics creative thinkingrefers to a combination of logical and divergent thinking which is basedon intuition but has a conscious aim. The divergent thinking is focusedon flexibility, fluency, and novelty in mathematical problem solving andproblem posing. As students have various backgrounds and differentabilities, they possess different potential in thinking patterns,imagination, fantasy and performance; therefore, students have differentlevels of creative thinking. A research study was conducted in order todevelop a framework for students’ levels of creative thinking inmathematics. This research used a qualitative approach to describe thecharacteristics of the levels of creative thinking. Task-based interviewswere conducted to collect data with ten 8thgrade junior secondary schoolstudents. The results distinguished five levels of creative thinking,namely level 0 to level 4 with different characteristics in each level.These differences are based on fluency, flexibility, and novelty inmathematical problem solving and problem posing.Keywords: student’s creative thinking, problem posing, flexibility,fluency, novelty DOI: http://dx.doi.org/10.22342/jme.1.1.794.17-40

  1. ONKALO POSE experiment. Phase 3: execution and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Valli, J. [Poeyry Finland Oy, Vantaa (Finland); Hakala, M. [KMS-Hakala Oy, Nokia (Finland); Wanne, T. [Saanio and Riekkola Oy, Helsinki (Finland); Kantia, P. [Geofcon Oy, Rovaniemi (Finland); Siren, T.

    2014-01-15

    In-depth knowledge of the in situ stress state at the Olkiluoto site is critical for stability assessment both prior to and after deposition of spent nuclear fuel in order to understand and avoid potential damage to the rock at the site. Posiva's Olkiluoto Spalling Experiment (POSE) was designed specifically for this purpose with three primary goals: establish the in situ spalling/damage strength of Olkiluoto migmatitic gneiss, establish the state of in situ stress at the -345 m depth level and act as a Prediction-Outcome (P-O) exercise. Phases 1 and 2 of POSE are outlined in WR 2012-60. The objectives of the third phase of the POSE experiment are the same as the original objectives outlined above. This report outlines the execution and results of the third phase of the POSE experiment. The third phase of the experiment involved internally heating the third experimental hole (ONK-EH3) of the POSE niche in order to cause a symmetrical thermal stress increase around the hole due to the thermal expansion of rock. This thermomechanically induced stress increase, coupled with the estimated existing in situ stress state, should cause the maximum principal stress around the hole to exceed the predicted spalling strength of the rock around the hole. ONK-EH3 is located almost completely in pegmatitic granite. Four fractures near the top of the hole were mapped after boring ONK-EH3, and a tensile failure located at the contact between mica-rich gneiss and pegmatitic granite was observed 18 months after boring, prior to the experiment. Based on predictive calculations and the estimated in situ state of stress, the maximum principal stress magnitude should reach ca. 100 MPa when the temperature was just below 100 deg C after 12 weeks of heating. There were problems with the heater control unit at the beginning of the experiment, after which heating proceeded according to plan. The crack damage threshold of pegmatitic granite has been determined to be 85 ±17 MPa at

  2. Regularization theory for ill-posed problems selected topics

    CERN Document Server

    Lu, Shuai

    2013-01-01

    Thismonograph is a valuable contribution to thehighly topical and extremly productive field ofregularisationmethods for inverse and ill-posed problems. The author is an internationally outstanding and acceptedmathematicianin this field. In his book he offers a well-balanced mixtureof basic and innovative aspects.He demonstrates new,differentiatedviewpoints, and important examples for applications. The bookdemontrates thecurrent developments inthe field of regularization theory,such as multiparameter regularization and regularization in learning theory. The book is written for graduate and PhDs

  3. A non-expert-user interface for posing signing avatars.

    Science.gov (United States)

    Adamo-Villani, Nicoletta; Popescu, Voicu; Lestina, Jason

    2013-05-01

    We describe a graphical user interface designed to allow non-expert users to pose 3D characters to create American Sign Language (ASL) computer animation. The interface is an important component of a software system that allows educators of the Deaf to add sign language translation, in the form of 3D character animations, to digital learning materials, thus making them accessible to deaf learners. A study indicates that users with no computer animation expertize can create animated ASL signs quickly and accurately.

  4. Patulin mycotoxicosis in the rat: toxicology, pathology and clinical pathology.

    Science.gov (United States)

    McKinley, E R; Carlton, W W; Boon, G D

    1982-06-01

    Patulin, a secondary metabolite produced by species of the genera Penicillium and Aspergillus, was administered to male Sprague-Dawley rats, weighing 50-60 g, by the oral, sc and ip routes. The 72-hr LD50 values (in mg/kg weight) were: oral, 55.0; sc, 11.0; ip, 10.0. Mortality was greatest 0-24 hr after administration by the oral and sc routes and 49-72 hr after ip dosing. Gross alterations consisted of gastric and intestinal hyperaemia and distention. Histopathological alterations consisted principally of ulceration and inflammation of the stomach. Patulin was administered orally to rats daily or every other day for 2 wk at doses of 50 or 75% of the oral LD50. Mortality in the treated groups was greater than in controls but was similar for all treated groups. No evidence of cumulative toxicity was found and the gross and histopathological alterations were similar to those found in the LD50 studies. Clinicopathological alterations included metabolic alkalosis with respiratory compensation, oliguria, decreased serum sodium, elevated blood glucose, reduced plasma protein and an elevated total leucocyte count which differential leucocyte counts indicated to be due to neutrophilia. The inflammatory alterations observed in the gastro-intestinal tract may be due to the irritant properties of patulin or to an alteration in the gastro-intestinal flora by the antibiotic activity of patulin.

  5. Probabilistic Mapping of Human Visual Attention from Head Pose Estimation

    Directory of Open Access Journals (Sweden)

    Andrea Veronese

    2017-10-01

    Full Text Available Effective interaction between a human and a robot requires the bidirectional perception and interpretation of actions and behavior. While actions can be identified as a directly observable activity, this might not be sufficient to deduce actions in a scene. For example, orienting our face toward a book might suggest the action toward “reading.” For a human observer, this deduction requires the direction of gaze, the object identified as a book and the intersection between gaze and book. With this in mind, we aim to estimate and map human visual attention as directed to a scene, and assess how this relates to the detection of objects and their related actions. In particular, we consider human head pose as measurement to infer the attention of a human engaged in a task and study which prior knowledge should be included in such a detection system. In a user study, we show the successful detection of attention to objects in a typical office task scenario (i.e., reading, working with a computer, studying an object. Our system requires a single external RGB camera for head pose measurements and a pre-recorded 3D point cloud of the environment.

  6. ONKALO POSE experiment. Phase 1 and 2: execution and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, E. [Saanio and Riekkola Oy, Helsinki (Finland); Siren, T. [Posiva Oy, Helsinki (Finland); Hakala, M. [KMS-Hakala Oy, Nokia (Finland); Kantia, P. [Geofcon Oy, Rovaniemi (Finland)

    2014-02-15

    Posiva has conducted in the ONKALO rock characterisation facility during 2010 - 2011 an in situ experiment named POSE (Posiva's Olkiluoto Spalling Experiment). The POSE experiment had three objectives: to establish the in situ spalling/damage strength of Olkiluoto migmatitic gneiss, to establish the state of in situ stress at the -345 m depth level, and to act as a Prediction-Outcome (P-O) exercise. The POSE experiment consisted of drilling with full-face boring machine two near fullscale deposition holes, diameter 1.52 m (compared to 1.75 m for the actual deposition holes), to a depth of 7.2 m, leaving a 0.9 m pillar between the holes. The holes were planned to be located in such way that maximum excavation-induced stresses could act in the pillar and damage could then take place. Boring of the two holes in 2010 was called Phase 1 (Pillar test). This was followed in 2011 by Phase 2 (Pillar heating test) where four heaters with a length of 7.5 m heated the test area to increase the stresses around the experimental holes. In the heating phase the other hole was back-filled with sand. The test was extensively monitored during the execution using temperature monitoring, strain gauge monitoring, video monitoring, microseismic monitoring and pressure monitoring. In addition, the holes were after the test measured using ground penetration radar (GPR) and 3D photogrammetry for detailed modelling. The outcomes from the test showed that no damage, except for three opened/sheared fractures, was noticed during the boring of the holes (Phase 1). Surface damage was, though, induced by heating (Phase 2). The damage was well localized around the holes and controlled by the foliation (mica rich layers) and rock type contacts which were known to be relatively weak. Surface type failures were not observed in the gneiss, but it was noticed in limited areas in the pegmatite-granite. The depths of the damaged areas due to heating were less than 100 mm. The depths and sizes of the

  7. EFEKTIVITAS PEMBELAJARAN MATEMATIKA DENGAN METODE PROBLEM POSING BERBASIS PENDIDIKAN KARAKTER

    Directory of Open Access Journals (Sweden)

    Eka Lia Susanti

    2012-06-01

    Full Text Available Abstract Tujuan penelitian ini adalah untuk mengetahui apakah pembelajaran matematika dengan metode Problem Posing berbasis pendidikan karakter di laboratorium TeenZania pada materi garis singgung lingkaran efektif. Populasi dalam penelitian ini adalah peserta didik di SMP N 2 Pati. Sampel dalam penelitian ini diambil dengan teknik cluster random sampling. Variabel dalam penelitian ini yaitu keaktifan sebagai variabel independen dan prestasi belajar sebagai variabel dependen. Cara pengambilan data dengan lembar pengamatan dan tes. Data diolah dengan uji banding t dan uji pengaruh regresi. Hasil penelitian menunjukkan bahwa prestasi belajar kelas eksperimen (82,74 secara statistik melebihi KKM (75. Dengan uji regresi linear sederhana diperoleh persamaan regresi ?=-15,847 + 1,194X dan R^2=0,829. Koefisien X merupakan bilangan positif sehingga keaktifan berpengaruh positif pada prestasi belajar sebesar 82,9%. Rata-rata prestasi belajar kelas eksperimen (82,74 dan rata-rata prestasi belajar kelas kontrol (72,91. Secara uji stastistik prestasi belajar kelas eksperimen lebih baik daripada prestasi belajar kelas kontrol. Berdasarkan hasil analisis disimpulkan (1 pembelajaran mencapai tuntas belajar; (2 adanya pengaruh positif pada keaktifan terhadap prestasi belajar; dan (3 prestasi belajar kelas eksperimen lebih baik daripada prestasi belajar kelas kontrol; sehingga pembelajaran matematika dengan metode problem posing berbasis pendidikan karakter di laboratorium TeenZania merupakan pembelajaran yang efektif. The purpose of this study was to determine whether the learning of mathematics by Problem Posing method in a TeenZania laboratory based character education in circle tangent material effectively. The population in this study were students in SMP N 2 Pati. The sample in this study were drawn by cluster random sampling technique. The variables in this study is the activity as an independent variable and learning achievement as the dependent variable

  8. Pose Estimation for Augmented Reality: A Hands-On Survey.

    Science.gov (United States)

    Marchand, Eric; Uchiyama, Hideaki; Spindler, Fabien

    2016-12-01

    Augmented reality (AR) allows to seamlessly insert virtual objects in an image sequence. In order to accomplish this goal, it is important that synthetic elements are rendered and aligned in the scene in an accurate and visually acceptable way. The solution of this problem can be related to a pose estimation or, equivalently, a camera localization process. This paper aims at presenting a brief but almost self-contented introduction to the most important approaches dedicated to vision-based camera localization along with a survey of several extension proposed in the recent years. For most of the presented approaches, we also provide links to code of short examples. This should allow readers to easily bridge the gap between theoretical aspects and practical implementations.

  9. Challenges Posed by Novel Psychoactive Substances – Middle East Perspective

    Directory of Open Access Journals (Sweden)

    Maciej J. Bogusz

    2017-04-01

    Full Text Available New psychoactive substances (NPS are defined as substances of abuse, either in a pure form or a preparation, that are not controlled by the 1961 Single Convention on Narcotic Drugs or the 1971 Convention on Psychotropic Substances, but which may pose a public health threat. In this context, the term “new” does not necessarily refer to new inventions but to substances that have recently become available or popular in a given society or country. This definition indicates that the problem of NPS is not new; however, the availability of any information via new communication technologies in the 21st century has enabled the spread of unwanted and socially harmful information, like information on the commercial availability of various NPS, offered in rising amounts and brands.

  10. Robustifying Correspondence Based 6D Object Pose Estimation

    DEFF Research Database (Denmark)

    Hietanen, Antti; Halme, Jussi; Buch, Anders Glent

    2017-01-01

    We propose two methods to robustify point correspondence based 6D object pose estimation. The first method, curvature filtering, is based on the assumption that low curvature regions provide false matches, and removing points in these regions improves robustness. The second method, region pruning......, is more general by making no assumptions about local surface properties. Our region pruning segments a model point cloud into cluster regions and searches good region combinations using a validation set. The robustifying methods are general and can be used with any correspondence based method....... For the experiments, we evaluated three correspondence selection methods, Geometric Consistency (GC) [1], Hough Grouping (HG) [2] and Search of Inliers (SI) [3] and report systematic improvements for their robustified versions with two distinct datasets....

  11. Level of environmental threat posed by horticultural trade in Cactaceae.

    Science.gov (United States)

    Novoa, Ana; Le Roux, Johannes J; Richardson, David M; Wilson, John R U

    2017-10-01

    Ornamental horticulture has been identified as an important threat to plant biodiversity and is a major pathway for plant invasions worldwide. In this context, the family Cactaceae is particularly challenging because it is considered the fifth most threatened large taxonomic group in the world; several species are among the most widespread and damaging invasive species; and Cactaceae is one of the most popular horticultural plant groups. Based on the Convention on International Trade in Endangered Species of Wild Flora and Fauna and the 11 largest online auction sites selling cacti, we documented the international cactus trade. To provide an in-depth look at the dynamics of the industry, we surveyed the businesses involved in the cactus trade in South Africa (a hotspot of cactus trade and invasions). We purchased seeds of every available species and used DNA barcoding to identify species to the genus level. Although <20% of this trade involved threatened species and <3% involved known invasive species, many species were identified by a common name. However, only 0.02% of the globally traded cacti were collected from wild populations. Despite a large commercial network, all South African imports (of which 15% and 1.5% were of species listed as threatened and invasive, respectively) came from the same source. With DNA barcoding, we identified 24% of the species to genus level. Based on our results, we believe that if trade restrictions are placed on the small proportion of cacti that are invasive and there is no major increase in harvesting of native populations, then the commercial trade in cactus poses a negligible environmental threat. However, there are currently no effective methods for easily identifying which cacti are traded, and both the illicit harvesting of cacti from the wild and the informal trade in invasive taxa pose on-going conservation challenges. © 2017 Society for Conservation Biology.

  12. Assessing the risk posed by natural hazards to infrastructures

    Science.gov (United States)

    Eidsvig, Unni Marie K.; Kristensen, Krister; Vidar Vangelsten, Bjørn

    2017-03-01

    This paper proposes a model for assessing the risk posed by natural hazards to infrastructures, with a focus on the indirect losses and loss of stability for the population relying on the infrastructure. The model prescribes a three-level analysis with increasing level of detail, moving from qualitative to quantitative analysis. The focus is on a methodology for semi-quantitative analyses to be performed at the second level. The purpose of this type of analysis is to perform a screening of the scenarios of natural hazards threatening the infrastructures, identifying the most critical scenarios and investigating the need for further analyses (third level). The proposed semi-quantitative methodology considers the frequency of the natural hazard, different aspects of vulnerability, including the physical vulnerability of the infrastructure itself, and the societal dependency on the infrastructure. An indicator-based approach is applied, ranking the indicators on a relative scale according to pre-defined ranking criteria. The proposed indicators, which characterise conditions that influence the probability of an infrastructure malfunctioning caused by a natural event, are defined as (1) robustness and buffer capacity, (2) level of protection, (3) quality/level of maintenance and renewal, (4) adaptability and quality of operational procedures and (5) transparency/complexity/degree of coupling. Further indicators describe conditions influencing the socio-economic consequences of the infrastructure malfunctioning, such as (1) redundancy and/or substitution, (2) cascading effects and dependencies, (3) preparedness and (4) early warning, emergency response and measures. The aggregated risk estimate is a combination of the semi-quantitative vulnerability indicators, as well as quantitative estimates of the frequency of the natural hazard, the potential duration of the infrastructure malfunctioning (e.g. depending on the required restoration effort) and the number of users of

  13. EVALUATION OF POTENTIAL RISK POSED BY MEDICATIONS TO THE FETUS

    Directory of Open Access Journals (Sweden)

    S.A. Sher

    2010-01-01

    Full Text Available The article focuses on the issue of evaluating potential risk posed by medications to the fetus during pregnancy. For this purpose various countries use classifications of medications broken down into risk categories during pregnancy. The most popular classification is US FDA classification, which identifies five categories of medications (А, В, С, D and Х depending on the degree of their embryotoxic and teratogenic side effect, which enables physicians to make informed choices in selecting pharmacotherapy during the entire gestational period. The article discusses possible specific fetal and neonatal disorders when administering medications in categories X and D. Medications in category D may be prescribed to pregnant women only in extreme situations. Administering medications in category X is absolutely inadvisable before and during pregnancy. Further research in this area makes it possible to improve the classification of medications by degree of their embryotoxic and teratogenic risk and address the issue of selecting safe medications during pregnancy. Key words: medications, gestational period, embryo, fetus, embryotoxic and teratogenic action, fetal and neonatal disorders. (Pediatric Pharmacology. – 2010; 7(3:78-81

  14. Real-time pose invariant logo and pattern detection

    Science.gov (United States)

    Sidla, Oliver; Kottmann, Michal; Benesova, Wanda

    2011-01-01

    The detection of pose invariant planar patterns has many practical applications in computer vision and surveillance systems. The recognition of company logos is used in market studies to examine the visibility and frequency of logos in advertisement. Danger signs on vehicles could be detected to trigger warning systems in tunnels, or brand detection on transport vehicles can be used to count company-specific traffic. We present the results of a study on planar pattern detection which is based on keypoint detection and matching of distortion invariant 2d feature descriptors. Specifically we look at the keypoint detectors of type: i) Lowe's DoG approximation from the SURF algorithm, ii) the Harris Corner Detector, iii) the FAST Corner Detector and iv) Lepetit's keypoint detector. Our study then compares the feature descriptors SURF and compact signatures based on Random Ferns: we use 3 sets of sample images to detect and match 3 logos of different structure to find out which combinations of keypoint detector/feature descriptors work well. A real-world test tries to detect vehicles with a distinctive logo in an outdoor environment under realistic lighting and weather conditions: a camera was mounted on a suitable location for observing the entrance to a parking area so that incoming vehicles could be monitored. In this 2 hour long recording we can successfully detect a specific company logo without false positives.

  15. Mendalami Dasar-Dasar dalam Pengambilan Pose pada Pemotretan Model

    Directory of Open Access Journals (Sweden)

    Agnes Paulina Gunawan

    2013-04-01

    Full Text Available There are many activities and numerous objects in this universe, which make them interesting for photographers to explore as their masterpiece. One of the things that has been enjoyed and is always developing over time is the use of human as an object, whether as a candid photography or as a posing model in accordance to photographer's concept and theme. Using human being as an object is always popular among beginners and professional photographers. Even nowadays people often hold photo shoot as a media in many social network sites. And so if they understand the simple theories in basic knowledge of using human object, the results will be maximized, and of course, much more interesting. The more a photographer does his job, the better his experience is, and his work will develop. Thus, it makes him more alert to the situation and character of a model, which will then become more observant in predicting their outcome in photography.   

  16. Pose invariant face recognition: 3D model from single photo

    Science.gov (United States)

    Napoléon, Thibault; Alfalou, Ayman

    2017-02-01

    Face recognition is widely studied in the literature for its possibilities in surveillance and security. In this paper, we report a novel algorithm for the identification task. This technique is based on an optimized 3D modeling allowing to reconstruct faces in different poses from a limited number of references (i.e. one image by class/person). Particularly, we propose to use an active shape model to detect a set of keypoints on the face necessary to deform our synthetic model with our optimized finite element method. Indeed, in order to improve our deformation, we propose a regularization by distances on graph. To perform the identification we use the VanderLugt correlator well know to effectively address this task. On the other hand we add a difference of Gaussian filtering step to highlight the edges and a description step based on the local binary patterns. The experiments are performed on the PHPID database enhanced with our 3D reconstructed faces of each person with an azimuth and an elevation ranging from -30° to +30°. The obtained results prove the robustness of our new method with 88.76% of good identification when the classic 2D approach (based on the VLC) obtains just 44.97%.

  17. Crisis planning to manage risks posed by animal rights extremists.

    Science.gov (United States)

    Bailey, Matthew R; Rich, Barbara A; Bennett, B Taylor

    2010-01-01

    Among the multitude of crises that US research institutions may face are those caused by animal rights activists. While most activists opposed to animal research use peaceful and lawful means of expressing their opinions, some extremists resort to illegal methods. Arson, break-ins, and theft with significant property damage at US animal research facilities began in the 1980s. The most troubling trend to develop in the past decade is the targeting of individuals associated with animal research, whether directly or indirectly, and the use of violent scare tactics to intimidate researchers and their families. The National Association for Biomedical Research has a 30-year history of monitoring the animal rights movement and assisting member institutions with crisis situations. In this article we discuss attacks on researchers at their homes, cyber crimes, exploitation of new media formats, infiltration of research facilities, and the targeting of external research stakeholders and business partners. We describe the need for a well-conceived crisis management plan and strong leadership to mitigate crisis situations. Institutions with well-informed leaders and crisis management teams ready to take timely action are best equipped to protect staff, laboratory animals, and research programs. They act on early warnings, provide support for targeted staff, seek legal remedies, thoughtfully control access to research facilities, and identify and enlist new research supporters. We underscore the importance of up-to-date crisis planning so that institutions are not only aware of ongoing risks posed by animal rights extremists but also better prepared to take preemptive action and able to manage those risks successfully.

  18. Multi-view 3D Human Pose Estimation in Complex Environment

    NARCIS (Netherlands)

    Hofmann, K.M.; Gavrila, D.M.

    2012-01-01

    We introduce a framework for unconstrained 3D human upper body pose estimation from multiple camera views in complex environment. Its main novelty lies in the integration of three components: single-frame pose recovery, temporal integration and model texture adaptation. Single-frame pose recovery

  19. Investigation of Problem-Solving and Problem-Posing Abilities of Seventh-Grade Students

    Science.gov (United States)

    Arikan, Elif Esra; Ünal, Hasan

    2015-01-01

    This study aims to examine the effect of multiple problem-solving skills on the problem-posing abilities of gifted and non-gifted students and to assess whether the possession of such skills can predict giftedness or affect problem-posing abilities. Participants' metaphorical images of problem posing were also explored. Participants were 20 gifted…

  20. ErrorCheck: A New Method for Controlling the Accuracy of Pose Estimates

    DEFF Research Database (Denmark)

    Holm, Preben Hagh Strunge; Petersen, Henrik Gordon

    2011-01-01

    of a validated pose refinement method. ErrorCheck uses a theoretical estimate of the pose error covariance both for validating robustness and controlling the accuracy.We illustrate the first usage of ErrorCheck by applying it to state-of-the-art methods for pose refinement and some variations of these methods......In this paper, we present ErrorCheck, which is a new method for controlling the accuracy of a computer vision based pose refinement method. ErrorCheck consists of a way for validating robustness of a pose refinement method towards false correspondences and a way of controlling the accuracy...

  1. Creativity of Field-dependent and Field-independent Students in Posing Mathematical Problems

    Science.gov (United States)

    Azlina, N.; Amin, S. M.; Lukito, A.

    2018-01-01

    This study aims at describing the creativity of elementary school students with different cognitive styles in mathematical problem-posing. The posed problems were assessed based on three components of creativity, namely fluency, flexibility, and novelty. The free-type problem posing was used in this study. This study is a descriptive research with qualitative approach. Data collections were conducted through written task and task-based interviews. The subjects were two elementary students. One of them is Field Dependent (FD) and the other is Field Independent (FI) which were measured by GEFT (Group Embedded Figures Test). Further, the data were analyzed based on creativity components. The results show thatFD student’s posed problems have fulfilled the two components of creativity namely fluency, in which the subject posed at least 3 mathematical problems, and flexibility, in whichthe subject posed problems with at least 3 different categories/ideas. Meanwhile,FI student’s posed problems have fulfilled all three components of creativity, namely fluency, in which thesubject posed at least 3 mathematical problems, flexibility, in which thesubject posed problems with at least 3 different categories/ideas, and novelty, in which the subject posed problems that are purely the result of her own ideas and different from problems they have known.

  2. Point Cloud Based Relative Pose Estimation of a Satellite in Close Range

    Directory of Open Access Journals (Sweden)

    Lujiang Liu

    2016-06-01

    Full Text Available Determination of the relative pose of satellites is essential in space rendezvous operations and on-orbit servicing missions. The key problems are the adoption of suitable sensor on board of a chaser and efficient techniques for pose estimation. This paper aims to estimate the pose of a target satellite in close range on the basis of its known model by using point cloud data generated by a flash LIDAR sensor. A novel model based pose estimation method is proposed; it includes a fast and reliable pose initial acquisition method based on global optimal searching by processing the dense point cloud data directly, and a pose tracking method based on Iterative Closest Point algorithm. Also, a simulation system is presented in this paper in order to evaluate the performance of the sensor and generate simulated sensor point cloud data. It also provides truth pose of the test target so that the pose estimation error can be quantified. To investigate the effectiveness of the proposed approach and achievable pose accuracy, numerical simulation experiments are performed; results demonstrate algorithm capability of operating with point cloud directly and large pose variations. Also, a field testing experiment is conducted and results show that the proposed method is effective.

  3. Swimmer detection and pose estimation for continuous stroke-rate determination

    Science.gov (United States)

    Zecha, Dan; Greif, Thomas; Lienhart, Rainer

    2012-02-01

    In this work we propose a novel approach to automatically detect a swimmer and estimate his/her pose continuously in order to derive an estimate of his/her stroke rate given that we observe the swimmer from the side. We divide a swimming cycle of each stroke into several intervals. Each interval represents a pose of the stroke. We use specifically trained object detectors to detect each pose of a stroke within a video and count the number of occurrences per time unit of the most distinctive poses (so-called key poses) of a stroke to continuously infer the stroke rate. We extensively evaluate the overall performance and the influence of the selected poses for all swimming styles on a data set consisting of a variety of swimmers.

  4. Making 2D face recognition more robust using AAMs for pose compensation

    NARCIS (Netherlands)

    Huisman, Peter; Munster, Ruud; Moro-Ellenberger, Stephanie; Veldhuis, Raymond N.J.; Bazen, A.M.

    2006-01-01

    The problem of pose in 2D face recognition is widely acknowledged. Commercial systems are limited to near frontal face images and cannot deal with pose deviations larger than 15 degrees from the frontal view. This is a problem, when using face recognition for surveillance applications in which

  5. An Investigation of Relationships between Students' Mathematical Problem-Posing Abilities and Their Mathematical Content Knowledge

    Science.gov (United States)

    Van Harpen, Xianwei Y.; Presmeg, Norma C.

    2013-01-01

    The importance of students' problem-posing abilities in mathematics has been emphasized in the K-12 curricula in the USA and China. There are claims that problem-posing activities are helpful in developing creative approaches to mathematics. At the same time, there are also claims that students' mathematical content knowledge could be highly…

  6. Generalizability Theory Research on Developing a Scoring Rubric to Assess Primary School Students' Problem Posing Skills

    Science.gov (United States)

    Cankoy, Osman; Özder, Hasan

    2017-01-01

    The aim of this study is to develop a scoring rubric to assess primary school students' problem posing skills. The rubric including five dimensions namely solvability, reasonability, mathematical structure, context and language was used. The raters scored the students' problem posing skills both with and without the scoring rubric to test the…

  7. Example-based pose estimation in monocular images using compact fourier descriptors

    NARCIS (Netherlands)

    Poppe, Ronald Walter; Poel, Mannes

    2005-01-01

    Automatically estimating human poses from visual input is useful but challenging due to variations in image space and the high dimensionality of the pose space. In this paper, we assume that a human silhouette can be extracted from monocular visual input. We compare the recovery performance of

  8. Comparison of Silhouette Shape Descriptors for Example-based Human Pose Recovery

    NARCIS (Netherlands)

    Poppe, Ronald Walter; Poel, Mannes

    2006-01-01

    Automatically recovering human poses from visual input is useful but challenging due to variations in image space and the high dimensionality of the pose space. In this paper, we assume that a human silhouette can be extracted from monocular visual input. We compare three shape descriptors that are

  9. Body-part templates for recovery of 2D human poses under occlusion

    NARCIS (Netherlands)

    Poppe, Ronald Walter; Poel, Mannes; Perales, F.J.; Fisher, R.B.

    2008-01-01

    Detection of humans and estimation of their 2D poses from a single image are challenging tasks. This is especially true when part of the observation is occluded. However, given a limited class of movements, poses can be recovered given the visible body-parts. To this end, we propose a novel template

  10. Head Pose Estimation Using Multilinear Subspace Analysis for Robot Human Awareness

    Science.gov (United States)

    Ivanov, Tonislav; Matthies, Larry; Vasilescu, M. Alex O.

    2009-01-01

    Mobile robots, operating in unconstrained indoor and outdoor environments, would benefit in many ways from perception of the human awareness around them. Knowledge of people's head pose and gaze directions would enable the robot to deduce which people are aware of the its presence, and to predict future motions of the people for better path planning. To make such inferences, requires estimating head pose on facial images that are combination of multiple varying factors, such as identity, appearance, head pose, and illumination. By applying multilinear algebra, the algebra of higher-order tensors, we can separate these factors and estimate head pose regardless of subject's identity or image conditions. Furthermore, we can automatically handle uncertainty in the size of the face and its location. We demonstrate a pipeline of on-the-move detection of pedestrians with a robot stereo vision system, segmentation of the head, and head pose estimation in cluttered urban street scenes.

  11. Trajectory Planning with Pose Feedback for a Dual-Arm Space Robot

    Directory of Open Access Journals (Sweden)

    Yicheng Liu

    2016-01-01

    Full Text Available In order to obtain high precision path tracking for a dual-arm space robot, a trajectory planning method with pose feedback is proposed to be introduced into the design process in this paper. Firstly, pose error kinematic models are derived from the related kinematics and desired pose command for the end-effector and the base, respectively. On this basis, trajectory planning with pose feedback is proposed from a control perspective. Theoretical analyses show that the proposed trajectory planning algorithm can guarantee that pose error converges to zero exponentially for both the end-effector and the base when the robot is out of singular configuration. Compared with the existing algorithms, the proposed algorithm can lead to higher precision path tracking for the end-effector. Furthermore, the algorithm renders the system good anti-interference property for the base. Simulation results demonstrate the effectiveness of the proposed trajectory planning algorithm.

  12. Pose-robust face recognition using shape-adapted texture features

    Science.gov (United States)

    Gernoth, Thorsten; Goossen, André; Grigat, Rolf-Rainer

    2011-03-01

    Unconstrained environments with variable ambient illumination and changes of head pose are still challenging for many face recognition systems. To recognize a person independent of pose, we first fit an active appearance model to a given facial image. Shape information is used to transform the face into a pose-normalized representation. We decompose the transformed face into local regions and extract texture features from these not necessarily rectangular regions using a shape-adapted discrete cosine transform. We show that these features contain sufficient discriminative information to recognize persons across changes in pose. Furthermore, our experimental results show a significant improvement in face recognition performance on faces with pose variations when compared with a block-DCT based feature extraction technique in an access control scenario.

  13. Attribute And-Or Grammar for Joint Parsing of Human Pose, Parts and Attributes.

    Science.gov (United States)

    Park, Seyoung; Nie, Xiaohan; Zhu, Song-Chun

    2017-07-25

    This paper presents an attribute and-or grammar (A-AOG) model for jointly inferring human body pose and human attributes in a parse graph with attributes augmented to nodes in the hierarchical representation. In contrast to other popular methods in the current literature that train separate classifiers for poses and individual attributes, our method explicitly represents the decomposition and articulation of body parts, and account for the correlations between poses and attributes. The A-AOG model is an amalgamation of three traditional grammar formulations: (i)Phrase structure grammar representing the hierarchical decomposition of the human body from whole to parts; (ii)Dependency grammar modeling the geometric articulation by a kinematic graph of the body pose; and (iii)Attribute grammar accounting for the compatibility relations between different parts in the hierarchy so that their appearances follow a consistent style. The parse graph outputs human detection, pose estimation, and attribute prediction simultaneously, which are intuitive and interpretable. We conduct experiments on two tasks on two datasets, and experimental results demonstrate the advantage of joint modeling in comparison with computing poses and attributes independently. Furthermore, our model obtains better performance over existing methods for both pose estimation and attribute prediction tasks.

  14. A Gaussian process guided particle filter for tracking 3D human pose in video.

    Science.gov (United States)

    Sedai, Suman; Bennamoun, Mohammed; Huynh, Du Q

    2013-11-01

    In this paper, we propose a hybrid method that combines Gaussian process learning, a particle filter, and annealing to track the 3D pose of a human subject in video sequences. Our approach, which we refer to as annealed Gaussian process guided particle filter, comprises two steps. In the training step, we use a supervised learning method to train a Gaussian process regressor that takes the silhouette descriptor as an input and produces multiple output poses modeled by a mixture of Gaussian distributions. In the tracking step, the output pose distributions from the Gaussian process regression are combined with the annealed particle filter to track the 3D pose in each frame of the video sequence. Our experiments show that the proposed method does not require initialization and does not lose tracking of the pose. We compare our approach with a standard annealed particle filter using the HumanEva-I dataset and with other state of the art approaches using the HumanEva-II dataset. The evaluation results show that our approach can successfully track the 3D human pose over long video sequences and give more accurate pose tracking results than the annealed particle filter.

  15. Monocular-Based 6-Degree of Freedom Pose Estimation Technology for Robotic Intelligent Grasping Systems

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2017-02-01

    Full Text Available Industrial robots are expected to undertake ever more advanced tasks in the modern manufacturing industry, such as intelligent grasping, in which robots should be capable of recognizing the position and orientation of a part before grasping it. In this paper, a monocular-based 6-degree of freedom (DOF pose estimation technology to enable robots to grasp large-size parts at informal poses is proposed. A camera was mounted on the robot end-flange and oriented to measure several featured points on the part before the robot moved to grasp it. In order to estimate the part pose, a nonlinear optimization model based on the camera object space collinearity error in different poses is established, and the initial iteration value is estimated with the differential transformation. Measuring poses of the camera are optimized based on uncertainty analysis. Also, the principle of the robotic intelligent grasping system was developed, with which the robot could adjust its pose to grasp the part. In experimental tests, the part poses estimated with the method described in this paper were compared with those produced by a laser tracker, and results show the RMS angle and position error are about 0.0228° and 0.4603 mm. Robotic intelligent grasping tests were also successfully performed in the experiments.

  16. Monocular-Based 6-Degree of Freedom Pose Estimation Technology for Robotic Intelligent Grasping Systems.

    Science.gov (United States)

    Liu, Tao; Guo, Yin; Yang, Shourui; Yin, Shibin; Zhu, Jigui

    2017-02-14

    Industrial robots are expected to undertake ever more advanced tasks in the modern manufacturing industry, such as intelligent grasping, in which robots should be capable of recognizing the position and orientation of a part before grasping it. In this paper, a monocular-based 6-degree of freedom (DOF) pose estimation technology to enable robots to grasp large-size parts at informal poses is proposed. A camera was mounted on the robot end-flange and oriented to measure several featured points on the part before the robot moved to grasp it. In order to estimate the part pose, a nonlinear optimization model based on the camera object space collinearity error in different poses is established, and the initial iteration value is estimated with the differential transformation. Measuring poses of the camera are optimized based on uncertainty analysis. Also, the principle of the robotic intelligent grasping system was developed, with which the robot could adjust its pose to grasp the part. In experimental tests, the part poses estimated with the method described in this paper were compared with those produced by a laser tracker, and results show the RMS angle and position error are about 0.0228° and 0.4603 mm. Robotic intelligent grasping tests were also successfully performed in the experiments.

  17. Coupled multiview autoencoders with locality sensitivity for three-dimensional human pose estimation

    Science.gov (United States)

    Yu, Jialin; Sun, Jifeng; Luo, Shasha; Duan, Bichao

    2017-09-01

    Estimating three-dimensional (3D) human poses from a single camera is usually implemented by searching pose candidates with image descriptors. Existing methods usually suppose that the mapping from feature space to pose space is linear, but in fact, their mapping relationship is highly nonlinear, which heavily degrades the performance of 3D pose estimation. We propose a method to recover 3D pose from a silhouette image. It is based on the multiview feature embedding (MFE) and the locality-sensitive autoencoders (LSAEs). On the one hand, we first depict the manifold regularized sparse low-rank approximation for MFE and then the input image is characterized by a fused feature descriptor. On the other hand, both the fused feature and its corresponding 3D pose are separately encoded by LSAEs. A two-layer back-propagation neural network is trained by parameter fine-tuning and then used to map the encoded 2D features to encoded 3D poses. Our LSAE ensures a good preservation of the local topology of data points. Experimental results demonstrate the effectiveness of our proposed method.

  18. On pose determination using point features. [vision system for space robots

    Science.gov (United States)

    Hwang, Vincent; Keizer, Richard; Winkert, Tom; Spidaliere, Peter

    1992-01-01

    Consideration is given to the vision subsystem of an Orbital Replacement Unit (ORU) that was placed onto its base at Goddard Space Flight Center by a PUMA 762 robot equipped with a wrist-mounted CCD camera and a wrist-mounted force sensor. It is found that a simple adaptive thresholding method works quite well for images taken under various lighting conditions. The pose computed using the quadrangle method is reasonable for real images. In the presence of image feature noise the accuracy of the computed pose can be considerably reduced. This problem can be solved by using a 3D marker and an alternative pose computation algorithm.

  19. Pose estimation of occluded objects with an improved template matching method

    Science.gov (United States)

    Su, J. H.; Liu, Z. Y.; Yang, G.

    2016-07-01

    Picking up objects in arbitrary poses is an important step in manufacturing. However, the occlusion of object will cause the picking process difficult. This paper presents a hierarchical detection method to estimate the pose of the object such as rod and bearing even in occluding. Combining the ellipse detection with the template matching, it is possible to identify the pose of a target object that is not be occluded. The propose method will enable a robot to grasp a non-occluded object and ensure a successful picking. Experiments witness the validity the method.

  20. On Mathematical Problem Posing by Elementary Pre-teachers: The Case of Spreadsheets

    Directory of Open Access Journals (Sweden)

    Sergei Abramovich

    2008-07-01

    Full Text Available This article concerns the use of an electronic spreadsheet in mathematical problem posing by prospective elementary teachers. It introduces a didactic construct dealing with three types of a problem's coherence -- numerical, contextual and pedagogical. The main thesis of the article is that technological support of problem posing proves to be insufficient without one's use of this construct. The article reflects on work done with the teachers in a number of education courses. It suggests that including mathematics problem posing with spreadsheets into a coursework for the teachers provides them with research-like experience in curriculum development.

  1. Trotting Gait of a Quadruped Robot Based on the Time-Pose Control Method

    Directory of Open Access Journals (Sweden)

    Cai RunBin

    2013-02-01

    Full Text Available We present the Time-Pose control method for the trotting gait of a quadruped robot on flat ground and up a slope. The method, with brief control structure, real-time operation ability and high adaptability, divides quadruped robot control into gait control and pose control. Virtual leg and intuitive controllers are introduced to simplify the model and generate the trajectory of mass centre and location of supporting legs in gait control, while redundancy optimization is used for solving the inverse kinematics in pose control. The models both on flat ground and up a slope are fully analysed, and different kinds of optimization methods are compared using the manipulability measure in order to select the best option. Simulations are performed, which prove that the Time-Pose control method is realizable for these two kinds of environment.

  2. A Grasp-Pose Generation Method Based on Gaussian Mixture Models

    Directory of Open Access Journals (Sweden)

    Wenjia Wu

    2015-11-01

    Full Text Available A Gaussian Mixture Model (GMM-based grasp-pose generation method is proposed in this paper. Through offline training, the GMM is set up and used to depict the distribution of the robot's reachable orientations. By dividing the robot's workspace into small 3D voxels and training the GMM for each voxel, a look-up table covering all the workspace is built with the x, y and z positions as the index and the GMM as the entry. Through the definition of Task Space Regions (TSR, an object's feasible grasp poses are expressed as a continuous region. With the GMM, grasp poses can be preferentially sampled from regions with high reachability probabilities in the online grasp-planning stage. The GMM can also be used as a preliminary judgement of a grasp pose's reachability. Experiments on both a simulated and a real robot show the superiority of our method over the existing method.

  3. Pose and Shape Reconstruction of a Noncooperative Spacecraft Using Camera and Range Measurements

    National Research Council Canada - National Science Library

    Renato Volpe; Marco Sabatini; Giovanni B. Palmerini

    2017-01-01

    .... Various mission architectures have been either tested in space or studied on Earth. The present study deals with on-orbit relative pose and shape estimation with the use of a monocular camera and a distance sensor...

  4. Well-posed continuum equations for granular flow with compressibility and μ(I)-rheology

    Science.gov (United States)

    Schaeffer, D. G.; Shearer, M.; Gray, J. M. N. T.

    2017-01-01

    Continuum modelling of granular flow has been plagued with the issue of ill-posed dynamic equations for a long time. Equations for incompressible, two-dimensional flow based on the Coulomb friction law are ill-posed regardless of the deformation, whereas the rate-dependent μ(I)-rheology is ill-posed when the non-dimensional inertial number I is too high or too low. Here, incorporating ideas from critical-state soil mechanics, we derive conditions for well-posedness of partial differential equations that combine compressibility with I-dependent rheology. When the I-dependence comes from a specific friction coefficient μ(I), our results show that, with compressibility, the equations are well-posed for all deformation rates provided that μ(I) satisfies certain minimal, physically natural, inequalities. PMID:28588402

  5. Well-posed continuum equations for granular flow with compressibility and μ(I)-rheology

    Science.gov (United States)

    Barker, T.; Schaeffer, D. G.; Shearer, M.; Gray, J. M. N. T.

    2017-05-01

    Continuum modelling of granular flow has been plagued with the issue of ill-posed dynamic equations for a long time. Equations for incompressible, two-dimensional flow based on the Coulomb friction law are ill-posed regardless of the deformation, whereas the rate-dependent μ(I)-rheology is ill-posed when the non-dimensional inertial number I is too high or too low. Here, incorporating ideas from critical-state soil mechanics, we derive conditions for well-posedness of partial differential equations that combine compressibility with I-dependent rheology. When the I-dependence comes from a specific friction coefficient μ(I), our results show that, with compressibility, the equations are well-posed for all deformation rates provided that μ(I) satisfies certain minimal, physically natural, inequalities.

  6. Using head poses to control a virtual robot walking in a virtualmaze

    Science.gov (United States)

    Zhao, Qingjie; Xu, Weicun; Wang, Yuxia; Shi, Xiaoming

    2013-05-01

    This paper develops a game system based on head pose identification techniques to control a virtual robot walking in a virtual maze environment built with Microsoft Robotics Developer Studio. Adaboost face classifiers are used to detect a face in the image and give a rough head pose classification. Two approaches are proposed to further determine more specific head poses. The first approach adopts PCA with nose template matching method, and the second one firstly uses a nose classifier to detect the nose in a detected face region and then directly utilizes the nose's relative position information to achieve head pose classification. A method to select the best nose area is proposed to solve the problem that multi-nose areas may be detected in one face region. Experiment results show that the two approaches have comparable time consumed, but the second approach provides more correct identification results.

  7. Well-posed continuum equations for granular flow with compressibility and $\\mu(I)$-rheology

    CERN Document Server

    Barker, T; Shearer, M; Gray, J M N T

    2016-01-01

    Continuum modelling of granular flow has been plagued with the issue of ill-posed equations for a long time. Equations for incompressible, two-dimensional flow based on the Coulomb friction law are ill-posed regardless of the deformation, whereas the rate-dependent $\\mu(I)$-rheology is ill-posed when the non-dimensional strain-rate $I$ is too high or too low. Here, incorporating ideas from Critical-State Soil Mechanics, we derive conditions for well-posedness of PDEs that combine compressibility with $I$-dependent rheology. When the $I$-dependence comes from a specific friction coefficient $\\mu(I)$, our results show that, with compressibility, the equations are well-posed for all deformation rates provided that $\\mu(I)$ satisfies certain minimal, physically natural, inequalities.

  8. The silent social/emotional signals in left and right cheek poses: a literature review.

    Science.gov (United States)

    Lindell, Annukka K

    2013-01-01

    When posing for a painted or photographic portrait, people are more likely to offer their left, rather than right, cheek (e.g., the Mona Lisa). Why? This paper reviews research investigating the left cheek bias, and the reasons underlying this posing asymmetry. Ruling out mechanical and perceptual biases, the paper focuses on the silent emotional and social signals conveyed by left and right cheek poses, demonstrating that people intuitively offer the left cheek to express emotion and perceive left cheek poses as more emotional. Moreover, because the left cheek appears more emotionally expressive, we unconsciously use cheek shown as a cue when presenting or determining academic specialisation, scientific standing, and even political affiliation. The research is consistent in suggesting that something as subtle as a 15° head turn implicitly influences others' perceptions: if you want to be perceived as open and creative, rather than dry and scientific, it might be time to turn the other cheek.

  9. Improved pose and affinity predictions using different protocols tailored on the basis of data availability

    Science.gov (United States)

    Prathipati, Philip; Nagao, Chioko; Ahmad, Shandar; Mizuguchi, Kenji

    2016-09-01

    The D3R 2015 grand drug design challenge provided a set of blinded challenges for evaluating the applicability of our protocols for pose and affinity prediction. In the present study, we report the application of two different strategies for the two D3R protein targets HSP90 and MAP4K4. HSP90 is a well-studied target system with numerous co-crystal structures and SAR data. Furthermore the D3R HSP90 test compounds showed high structural similarity to existing HSP90 inhibitors in BindingDB. Thus, we adopted an integrated docking and scoring approach involving a combination of both pharmacophoric and heavy atom similarity alignments, local minimization and quantitative structure activity relationships modeling, resulting in the reasonable prediction of pose [with the root mean square deviation (RMSD) values of 1.75 Å for mean pose 1, 1.417 Å for the mean best pose and 1.85 Å for the mean all poses] and affinity (ROC AUC = 0.702 at 7.5 pIC50 cut-off and R = 0.45 for 180 compounds). The second protein, MAP4K4, represents a novel system with limited SAR and co-crystal structure data and little structural similarity of the D3R MAP4K4 test compounds to known MAP4K4 ligands. For this system, we implemented an exhaustive pose and affinity prediction protocol involving docking and scoring using the PLANTS software which considers side chain flexibility together with protein-ligand fingerprints analysis assisting in pose prioritization. This protocol through fares poorly in pose prediction (with the RMSD values of 4.346 Å for mean pose 1, 4.69 Å for mean best pose and 4.75 Å for mean all poses) and produced reasonable affinity prediction (AUC = 0.728 at 7.5 pIC50 cut-off and R = 0.67 for 18 compounds, ranked 1st among 80 submissions).

  10. Consistently Showing Your Best Side? Intra-individual Consistency in #Selfie Pose Orientation.

    Science.gov (United States)

    Lindell, Annukka K

    2017-01-01

    Painted and photographic portraits of others show an asymmetric bias: people favor their left cheek. Both experimental and database studies confirm that the left cheek bias extends to selfies. To date all such selfie studies have been cross-sectional; whether individual selfie-takers tend to consistently favor the same pose orientation, or switch between multiple poses, remains to be determined. The present study thus examined intra-individual consistency in selfie pose orientations. Two hundred selfie-taking participants (100 male and 100 female) were identified by searching #selfie on Instagram. The most recent 10 single-subject selfies for the each of the participants were selected and coded for type of selfie (normal; mirror) and pose orientation (left, midline, right), resulting in a sample of 2000 selfies. Results indicated that selfie-takers do tend to consistently adopt a preferred pose orientation (α = 0.72), with more participants showing an overall left cheek bias (41%) than would be expected by chance (overall right cheek bias = 31.5%; overall midline bias = 19.5%; no overall bias = 8%). Logistic regression modellng, controlling for the repeated measure of participant identity, indicated that sex did not affect pose orientation. However, selfie type proved a significant predictor when comparing left and right cheek poses, with a stronger left cheek bias for mirror than normal selfies. Overall, these novel findings indicate that selfie-takers show intra-individual consistency in pose orientation, and in addition, replicate the previously reported left cheek bias for selfies and other types of portrait, confirming that the left cheek bias also presents within individuals' selfie corpora.

  11. A review of cooperative and uncooperative spacecraft pose determination techniques for close-proximity operations

    Science.gov (United States)

    Opromolla, Roberto; Fasano, Giancarmine; Rufino, Giancarlo; Grassi, Michele

    2017-08-01

    The capability of an active spacecraft to accurately estimate its relative position and attitude (pose) with respect to an active/inactive, artificial/natural space object (target) orbiting in close-proximity is required to carry out various activities like formation flying, on-orbit servicing, active debris removal, and space exploration. According to the specific mission scenario, the pose determination task involves both theoretical and technological challenges related to the search for the most suitable algorithmic solution and sensor architecture, respectively. As regards the latter aspect, electro-optical sensors represent the best option as their use is compatible with mass and power limitation of micro and small satellites, and their measurements can be processed to estimate all the pose parameters. Overall, the degree of complexity of the challenges related to pose determination largely varies depending on the nature of the targets, which may be actively/passively cooperative, uncooperative but known, or uncooperative and unknown space objects. In this respect, while cooperative pose determination has been successfully demonstrated in orbit, the uncooperative case is still under study by universities, research centers, space agencies and private companies. However, in both the cases, the demand for space applications involving relative navigation maneuvers, also in close-proximity, for which pose determination capabilities are mandatory, is significantly increasing. In this framework, a review of state-of-the-art techniques and algorithms developed in the last decades for cooperative and uncooperative pose determination by processing data provided by electro-optical sensors is herein presented. Specifically, their main advantages and drawbacks in terms of achieved performance, computational complexity, and sensitivity to variability of pose and target geometry, are highlighted.

  12. Monocular-Based 6-Degree of Freedom Pose Estimation Technology for Robotic Intelligent Grasping Systems

    OpenAIRE

    Tao Liu; Yin Guo; Shourui Yang; Shibin Yin; Jigui Zhu

    2017-01-01

    Industrial robots are expected to undertake ever more advanced tasks in the modern manufacturing industry, such as intelligent grasping, in which robots should be capable of recognizing the position and orientation of a part before grasping it. In this paper, a monocular-based 6-degree of freedom (DOF) pose estimation technology to enable robots to grasp large-size parts at informal poses is proposed. A camera was mounted on the robot end-flange and oriented to measure several featured points...

  13. Consistently Showing Your Best Side? Intra-individual Consistency in #Selfie Pose Orientation

    Science.gov (United States)

    Lindell, Annukka K.

    2017-01-01

    Painted and photographic portraits of others show an asymmetric bias: people favor their left cheek. Both experimental and database studies confirm that the left cheek bias extends to selfies. To date all such selfie studies have been cross-sectional; whether individual selfie-takers tend to consistently favor the same pose orientation, or switch between multiple poses, remains to be determined. The present study thus examined intra-individual consistency in selfie pose orientations. Two hundred selfie-taking participants (100 male and 100 female) were identified by searching #selfie on Instagram. The most recent 10 single-subject selfies for the each of the participants were selected and coded for type of selfie (normal; mirror) and pose orientation (left, midline, right), resulting in a sample of 2000 selfies. Results indicated that selfie-takers do tend to consistently adopt a preferred pose orientation (α = 0.72), with more participants showing an overall left cheek bias (41%) than would be expected by chance (overall right cheek bias = 31.5%; overall midline bias = 19.5%; no overall bias = 8%). Logistic regression modellng, controlling for the repeated measure of participant identity, indicated that sex did not affect pose orientation. However, selfie type proved a significant predictor when comparing left and right cheek poses, with a stronger left cheek bias for mirror than normal selfies. Overall, these novel findings indicate that selfie-takers show intra-individual consistency in pose orientation, and in addition, replicate the previously reported left cheek bias for selfies and other types of portrait, confirming that the left cheek bias also presents within individuals’ selfie corpora. PMID:28270790

  14. Pose Estimation with a Kinect for Ergonomic Studies: Evaluation of the Accuracy Using a Virtual Mannequin

    Directory of Open Access Journals (Sweden)

    Pierre Plantard

    2015-01-01

    Full Text Available Analyzing human poses with a Kinect is a promising method to evaluate potentials risks of musculoskeletal disorders at workstations. In ecological situations, complex 3D poses and constraints imposed by the environment make it difficult to obtain reliable kinematic information. Thus, being able to predict the potential accuracy of the measurement for such complex 3D poses and sensor placements is challenging in classical experimental setups. To tackle this problem, we propose a new evaluation method based on a virtual mannequin. In this study, we apply this method to the evaluation of joint positions (shoulder, elbow, and wrist, joint angles (shoulder and elbow, and the corresponding RULA (a popular ergonomics assessment grid upper-limb score for a large set of poses and sensor placements. Thanks to this evaluation method, more than 500,000 configurations have been automatically tested, which would be almost impossible to evaluate with classical protocols. The results show that the kinematic information obtained by the Kinect software is generally accurate enough to fill in ergonomic assessment grids. However inaccuracy strongly increases for some specific poses and sensor positions. Using this evaluation method enabled us to report configurations that could lead to these high inaccuracies. As a supplementary material, we provide a software tool to help designers to evaluate the expected accuracy of this sensor for a set of upper-limb configurations. Results obtained with the virtual mannequin are in accordance with those obtained from a real subject for a limited set of poses and sensor placements.

  15. Postural Communication of Emotion: Perception of Distinct Poses of Five Discrete Emotions

    Directory of Open Access Journals (Sweden)

    Lukas D. Lopez

    2017-05-01

    Full Text Available Emotion can be communicated through multiple distinct modalities. However, an often-ignored channel of communication is posture. Recent research indicates that bodily posture plays an important role in the perception of emotion. However, research examining postural communication of emotion is limited by the variety of validated emotion poses and unknown cohesion of categorical and dimensional ratings. The present study addressed these limitations. Specifically, we examined individuals’ (1 categorization of emotion postures depicting 5 discrete emotions (joy, sadness, fear, anger, and disgust, (2 categorization of different poses depicting the same discrete emotion, and (3 ratings of valence and arousal for each emotion pose. Findings revealed that participants successfully categorized each posture as the target emotion, including disgust. Moreover, participants accurately identified multiple distinct poses within each emotion category. In addition to the categorical responses, dimensional ratings of valence and arousal revealed interesting overlap and distinctions between and within emotion categories. These findings provide the first evidence of an identifiable posture for disgust and instantiate the principle of equifinality of emotional communication through the inclusion of distinct poses within emotion categories. Additionally, the dimensional ratings corroborated the categorical data and provide further granularity for future researchers to consider in examining how distinct emotion poses are perceived.

  16. Multi-Task Convolutional Neural Network for Pose-Invariant Face Recognition

    Science.gov (United States)

    Yin, Xi; Liu, Xiaoming

    2018-02-01

    This paper explores multi-task learning (MTL) for face recognition. We answer the questions of how and why MTL can improve the face recognition performance. First, we propose a multi-task Convolutional Neural Network (CNN) for face recognition where identity classification is the main task and pose, illumination, and expression estimations are the side tasks. Second, we develop a dynamic-weighting scheme to automatically assign the loss weight to each side task, which is a crucial problem in MTL. Third, we propose a pose-directed multi-task CNN by grouping different poses to learn pose-specific identity features, simultaneously across all poses. Last but not least, we propose an energy-based weight analysis method to explore how CNN-based MTL works. We observe that the side tasks serve as regularizations to disentangle the variations from the learnt identity features. Extensive experiments on the entire Multi-PIE dataset demonstrate the effectiveness of the proposed approach. To the best of our knowledge, this is the first work using all data in Multi-PIE for face recognition. Our approach is also applicable to in-the-wild datasets for pose-invariant face recognition and achieves comparable or better performance than state of the art on LFW, CFP, and IJB-A datasets.

  17. Automatic pose correction for image-guided nonhuman primate brain surgery planning

    Science.gov (United States)

    Ghafurian, Soheil; Chen, Antong; Hines, Catherine; Dogdas, Belma; Bone, Ashleigh; Lodge, Kenneth; O'Malley, Stacey; Winkelmann, Christopher T.; Bagchi, Ansuman; Lubbers, Laura S.; Uslaner, Jason M.; Johnson, Colena; Renger, John; Zariwala, Hatim A.

    2016-03-01

    Intracranial delivery of recombinant DNA and neurochemical analysis in nonhuman primate (NHP) requires precise targeting of various brain structures via imaging derived coordinates in stereotactic surgeries. To attain targeting precision, the surgical planning needs to be done on preoperative three dimensional (3D) CT and/or MR images, in which the animals head is fixed in a pose identical to the pose during the stereotactic surgery. The matching of the image to the pose in the stereotactic frame can be done manually by detecting key anatomical landmarks on the 3D MR and CT images such as ear canal and ear bar zero position. This is not only time intensive but also prone to error due to the varying initial poses in the images which affects both the landmark detection and rotation estimation. We have introduced a fast, reproducible, and semi-automatic method to detect the stereotactic coordinate system in the image and correct the pose. The method begins with a rigid registration of the subject images to an atlas and proceeds to detect the anatomical landmarks through a sequence of optimization, deformable and multimodal registration algorithms. The results showed similar precision (maximum difference of 1.71 in average in-plane rotation) to a manual pose correction.

  18. Optimization-based non-cooperative spacecraft pose estimation using stereo cameras during proximity operations.

    Science.gov (United States)

    Zhang, Limin; Zhu, Feng; Hao, Yingming; Pan, Wang

    2017-05-20

    Pose estimation for spacecraft is widely recognized as an important technology for space applications. Many space missions require accurate relative pose between the chaser and the target spacecraft. Stereo-vision is a usual mean to estimate the pose of non-cooperative targets during proximity operations. However, the uncertainty of stereo-vision measurement is still an outstanding issue that needs to be solved. With binocular structure and the geometric structure of the object, we present a robust pose estimation method for non-cooperative spacecraft. Because the solar panel can provide strict geometry constraints, our approach takes the corner points of which as features. After stereo matching, an optimization-based method is proposed to estimate the relative pose between the two spacecraft. Simulation results show that our method improves the precision and robustness of pose estimation. Our system improves the performance with maximum 3D localization error less than 5% and relative rotation angle error less than 1°. Our laboratory experiments further validate the method.

  19. Postural Communication of Emotion: Perception of Distinct Poses of Five Discrete Emotions

    Science.gov (United States)

    Lopez, Lukas D.; Reschke, Peter J.; Knothe, Jennifer M.; Walle, Eric A.

    2017-01-01

    Emotion can be communicated through multiple distinct modalities. However, an often-ignored channel of communication is posture. Recent research indicates that bodily posture plays an important role in the perception of emotion. However, research examining postural communication of emotion is limited by the variety of validated emotion poses and unknown cohesion of categorical and dimensional ratings. The present study addressed these limitations. Specifically, we examined individuals’ (1) categorization of emotion postures depicting 5 discrete emotions (joy, sadness, fear, anger, and disgust), (2) categorization of different poses depicting the same discrete emotion, and (3) ratings of valence and arousal for each emotion pose. Findings revealed that participants successfully categorized each posture as the target emotion, including disgust. Moreover, participants accurately identified multiple distinct poses within each emotion category. In addition to the categorical responses, dimensional ratings of valence and arousal revealed interesting overlap and distinctions between and within emotion categories. These findings provide the first evidence of an identifiable posture for disgust and instantiate the principle of equifinality of emotional communication through the inclusion of distinct poses within emotion categories. Additionally, the dimensional ratings corroborated the categorical data and provide further granularity for future researchers to consider in examining how distinct emotion poses are perceived. PMID:28559860

  20. Postural Communication of Emotion: Perception of Distinct Poses of Five Discrete Emotions.

    Science.gov (United States)

    Lopez, Lukas D; Reschke, Peter J; Knothe, Jennifer M; Walle, Eric A

    2017-01-01

    Emotion can be communicated through multiple distinct modalities. However, an often-ignored channel of communication is posture. Recent research indicates that bodily posture plays an important role in the perception of emotion. However, research examining postural communication of emotion is limited by the variety of validated emotion poses and unknown cohesion of categorical and dimensional ratings. The present study addressed these limitations. Specifically, we examined individuals' (1) categorization of emotion postures depicting 5 discrete emotions (joy, sadness, fear, anger, and disgust), (2) categorization of different poses depicting the same discrete emotion, and (3) ratings of valence and arousal for each emotion pose. Findings revealed that participants successfully categorized each posture as the target emotion, including disgust. Moreover, participants accurately identified multiple distinct poses within each emotion category. In addition to the categorical responses, dimensional ratings of valence and arousal revealed interesting overlap and distinctions between and within emotion categories. These findings provide the first evidence of an identifiable posture for disgust and instantiate the principle of equifinality of emotional communication through the inclusion of distinct poses within emotion categories. Additionally, the dimensional ratings corroborated the categorical data and provide further granularity for future researchers to consider in examining how distinct emotion poses are perceived.

  1. KEEFEKTIFAN PENDEKATAN PROBLEM SOLVING DAN PROBLEM POSING DENGAN SETTING KOOPERATIF DALAM PEMBELAJARAN MATEMATIKA

    Directory of Open Access Journals (Sweden)

    Widha Nur Shanti

    2015-05-01

    Full Text Available Penelitian ini bertujuan untuk mendeskripsikan keefektifan pendekatan pembelajaran (problem solving dengan setting kooperatif dan problem posing dengan setting kooperatif dan membandingkan keefektifan pendekatan problem posing dengan setting kooperatif dan pendekatan problem solving dengan setting kooperatif pada pembelajaran matematika ditinjau dari ketercapaian standar kompeten-si, kemampuan berpikir kritis, dan kecerdasan emosional siswa. Jenis penelitian ini adalah quasi experiment dengan pretest-posttest nonequivalent comparison-group design. Populasi sampelnya adalah siswa Kelas X SMA Negeri 1 Pengasih dan siswa Kelas X2 dan X3.Untuk menguji keefektifan pendekatan pembelajaran (problem solving dengan setting kooperatif dan problem posing dengan setting kooperatif, data dianalisis menggunakan uji one sample t-test. Untuk menguji bahwa pendekatan problem posing dengan setting kooperatif lebih efektif daripada pendekatan problem solving dengan setting kooperatif, data dianalisis menggunakan MANOVA yang dilanjutkan dengan uji t-Bonferroni. Hasil penelitian menunjukkan bahwa pendekatan pembelajaran (problem solving dengan setting kooperatif dan problem posing dengan setting kooperatif efektif dan pendekatan problem posing dengan setting kooperatif lebih efektif daripada pendekatan problem solving dengan setting kooperatif pada pembelajaran matematika ditinjau dari ketercapaian standar kompetensi, kemampuan berpikir kritis, dan kecerdasan emosional siswa. Kata Kunci: pendekatan problem solving dengan setting kooperatif, pendekatan problem posing dengan setting kooperatif, ketercapaian standar kompetensi, kemampuan berpikir kritis, kecerdasan emosional.   THE EFFECTIVENESS OF COOPERATIVE PROBLEM SOLVING AND COOPERATIVE PROBLEM POSING APPROACHES IN MATHEMATICS LEARNING Abstract This study aims to describe the effectiveness of the cooperative problem solving and cooperative problem posing approaches and the more effectiveness of the cooperative

  2. The Effect of Problem Solving and Problem Posing Models and Innate Ability to Students Achievement

    Directory of Open Access Journals (Sweden)

    Ratna Kartika Irawati

    2015-04-01

    Full Text Available Pengaruh Model Problem Solving dan Problem Posing serta Kemampuan Awal terhadap Hasil Belajar Siswa   Abstract: Chemistry concepts understanding features abstract quality and requires higher order thinking skills. Yet, the learning on chemistry has not boost the higher order thinking skills of the students. The use of the learning model of Problem Solving and Problem Posing in observing the innate ability of the student is expected to resolve the issue. This study aims to determine the learning model which is effective to improve the study of the student with different level of innate ability. This study used the quasi-experimental design. The research data used in this research is the quiz/test of the class which consist of 14 multiple choice questions and 5 essay questions. The data analysis used is ANOVA Two Ways. The results showed that Problem Posing is more effective to improve the student compared to Problem Solving, students with high level of innate ability have better outcomes in learning rather than the students with low level of innate ability after being applied with the Problem solving and Problem posing model, further, Problem Solving and Problem Posing is more suitable to be applied to the students with high level of innate ability. Key Words: problem solving, problem posing, higher order thinking skills, innate ability, learning outcomes   Abstrak: Pemahaman konsep-konsep kimia yang bersifat abstrak membutuhkan keterampilan berpikir tingkat tinggi. Pembelajaran kimia belum mendorong siswa melakukan keterampilan berpikir tingkat tinggi. Penggunaan model pembelajaran Problem Solving dan Problem Posing dengan memperhatikan kemampuan awal siswa diduga dapat mengatasi masalah tersebut. Penelitian ini bertujuan untuk mengetahui model pembelajaran yang efektif dalam meningkatkan hasil belajar dengan kemampuan awal siswa yang berbeda. Penelitian ini menggunakan rancangan eksperimen semu. Data penelitian menggunakan tes hasil belajar

  3. Pose measurement method with six parameters for microassembly based on an optical micrometer

    Science.gov (United States)

    Ye, Xin; Wang, Qiang; Zhang, Zhi-jing; Sun, Yuan; Zhang, Xiao-feng

    2009-07-01

    This paper presents a new pose measurement method of microminiature parts that is capable of transforming one dimension (1D) contour size obtained by optical micrometer to three dimension (3D) data with six parameters for microassembly. Pose measurement is one of the most important processes for microminiature parts' alignment and insertion in microassembly. During the past few years, researchers have developed their microassembly systems focusing on visual identification to obtain two or three dimension data with no more than three parameters. Scanning electronic microscope (SEM), optical microscope, and stereomicroscope are applied in their systems. However, as structures of microminiature parts become increasingly complex, six parameters to represent their position and orientation are specifically needed. Firstly, The pose measurement model is established based on the introduction of measuring objects and measuring principle of optical micrometer. The measuring objects are microminiature parts with complex 3D structure. Two groups of two dimension (2D) data are gathered at two different measurement positions. Then part pose with 6 parameters is calculated, including 3 position parameters of feature point of the part and 3 orientation parameters of the part axis. Secondly, pose measurement process for a small shaft, vertical orientation determination, and position parameters obtaining are presented. 2D data is gathered by scanning the generatrix of the part, and valid data is extracted and saved in arrays. A vertical orientation criterion is proposed to determine whether the part is parallel to the Z-axis of the coordinate. If not, 2D data will be fixed into a linear equation using least square algorithm. Then orientation parameters are calculated. Center of Part End (CPE) is selected as feature point of the part, and its position parameters are extracted form two group of 2D data. Finally, a fast pose measurement device is developed and representative

  4. Combining Front Vehicle Detection with 3D Pose Estimation for a Better Driver Assistance

    Directory of Open Access Journals (Sweden)

    Yu Peng

    2012-09-01

    Full Text Available Driver assistant systems enhance traffic safety and efficiency. The accurate 3D pose of a front vehicle can help a driver to make the right decision on the road. We propose a novel real-time system to estimate the 3D pose of the front vehicle. This system consists of two parallel threads: vehicle rear tracking and mapping. The vehicle rear is first identified in the video captured by an onboard camera, after license plate localization and foreground extraction. The 3D pose estimation technique is then employed with respect to the extracted vehicle rear. Most current 3D pose estimation techniques need prior models or a stereo initialization with user cooperation. It is extremely difficult to obtain prior models due to the varying appearance of vehicles' rears. Moreover, it is unsafe to ask for drivers' cooperation when a vehicle is running. In our system, two initial keyframes for stereo algorithms are automatically extracted by vehicle rear detection and tracking. Map points are defined as a collection of point features extracted from the vehicle's rear with their 3D information. These map points are inferences that relate the 2D features detected in following vehicles' rears with the 3D world. The relative 3D pose of the onboard camera to the front vehicle rear is then estimated through matching the map points with point features detected on the front vehicle rear. We demonstrate the capabilities of our system by testing on real-time and synthesized videos. In order to make the experimental analysis visible, we demonstrated an estimated 3D pose through augmented reality, which needs accurate and real-time 3D pose estimation.

  5. KEEFEKTIFAN PEMBELAJARAN BERBASIS MASALAH DAN PROBLEM POSING DITINJAU DARI KEMAMPUAN BERPIKIR LOGIS DAN KRITIS

    Directory of Open Access Journals (Sweden)

    Tantan Sutandi Nugraha

    2015-05-01

    Full Text Available Penelitian ini bertujuan mendeskripsikan keefektifan pembelajaran matematika berbasis masalah, problem posing, dan pendekatan konvensional serta perbandingan keefektifannya ditinjau dari kemampuan berpikir logis dan kritis. Jenis penelitian adalah quasi experiment dengan pretest-posttest with nonequivalent group design. Populasi penelitian adalah 240 siswa kelas VIII SMP Negeri 2 Ciamis. Tiga kelas diambil secara acak untuk sampel penelitian, kemudian ditentukan lagi secara acak kelas eksperimen pertama, kelas eksperimen kedua, dan kelas kontrol. Instrumen yang digunakan adalah tes kemampuan berpikir logis dan tes kemampuan berpikir kritis yang terdiri atas soal pretest dan posttest. Teknik analisis data meliputi t-one sample test untuk menguji keefektifan masing-masing pendekatan pembelajaran dan MANOVA untuk menguji perbedaannya yang dilanjutkan dengan uji  univariat. Semua uji menggunakan taraf signifikansi 5%. Hasil penelitian menunjukkan bahwa: (1 pembelajaran berbasis masalah dan problem posing keduanya efektif ditinjau dari kemampuan berpikir kritis tetapi tidak efektif ditinjau dari kemampuan berpikir logis sedangkan pembelajaran konvensional tidak efektif ditinjau dari kemampuan berpikir logis maupun kemampuan berpikir kritis; (2 ditinjau dari kemampuan berpikir logis, tidak ada perbedaan yang signifikan antara pembelajaran berbasis masalah dan problem posing tetapi keduanya lebih unggul dibandingkan pembelajaran konvensional sedangkan jika ditinjau dari kemampuan berpikir kritis, pembelajaran berbasis masalah lebih unggul dibandingkan pembelajaran problem posing dan pembelajaran konvensional serta pembelajaran problem posing lebih unggul dibandingkan pembelajaran konvensional. Kata Kunci: pembelajaran berbasis masalah, problem posing, kemampuan berpikir logis, kemampuan berpikir kritis   THE EFFECTIVENESS OF PROBLEM-BASED LEARNING AND PROBLEM POSING IN TERM OF THE LOGICAL AND CRITICAL THINKING ABILITY Abstract This study aims to

  6. A Bayesian framework for human body pose tracking from depth image sequences.

    Science.gov (United States)

    Zhu, Youding; Fujimura, Kikuo

    2010-01-01

    This paper addresses the problem of accurate and robust tracking of 3D human body pose from depth image sequences. Recovering the large number of degrees of freedom in human body movements from a depth image sequence is challenging due to the need to resolve the depth ambiguity caused by self-occlusions and the difficulty to recover from tracking failure. Human body poses could be estimated through model fitting using dense correspondences between depth data and an articulated human model (local optimization method). Although it usually achieves a high accuracy due to dense correspondences, it may fail to recover from tracking failure. Alternately, human pose may be reconstructed by detecting and tracking human body anatomical landmarks (key-points) based on low-level depth image analysis. While this method (key-point based method) is robust and recovers from tracking failure, its pose estimation accuracy depends solely on image-based localization accuracy of key-points. To address these limitations, we present a flexible Bayesian framework for integrating pose estimation results obtained by methods based on key-points and local optimization. Experimental results are shown and performance comparison is presented to demonstrate the effectiveness of the proposed approach.

  7. Muscle utilization patterns vary by skill levels of the practitioners across specific yoga poses (asanas).

    Science.gov (United States)

    Ni, Meng; Mooney, Kiersten; Balachandran, Anoop; Richards, Luca; Harriell, Kysha; Signorile, Joseph F

    2014-08-01

    To compare muscle activation patterns in 14 dominant side muscles during different yoga poses across three skill levels. Mixed repeated-measures descriptive study. University neuromuscular research laboratory, Miami, US. A group of 36 yoga practitioners (9 M/27 F; mean ± SD, 31.6 ± 12.6 years) with at least 3 months yoga practice experience. Each of the 11 surya namaskar poses A and B was performed separately for 15s and the surface electromyography for 14 muscles were recorded. Normalized root mean square of the electromyographic signal (NrmsEMG) for 14 muscles (5 upper body, 4 trunk, 5 lower body). There were significant main effects of pose for all fourteen muscles except middle trapezius (phead, anterior deltoid, medial deltoid, upper rectus abdominis and gastrocnemius lateralis; p<.05). Post hoc analyses using Bonferroni comparisons indicated that different poses activated specific muscle groups; however, this varied by skill level. Our results indicate that different poses can produce specific muscle activation patterns which may vary due to practitioners' skill levels. This information can be used in designing rehabilitation and training programs and for cuing during yoga training. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Fringe-reflection photogrammetry based on poses calibration with planar mirror reflection

    Science.gov (United States)

    Xiao, Yong-Liang; Zhong, Jianxin; Zhang, Qican; Su, Xianyu; You, Zhisheng

    2017-10-01

    Since liquid crystal display (LCD) screen locates outside of the camera's field of view in fringe-reflection photogrammetry, fringes displayed on LCD screen are obtained through specular reflection by a fixed camera. Thus, the pose calibration between camera and LCD screen is one of the main challenges in fringe-reflection photogrammetry. A markerless planar mirror is used to reflect the LCD screen more than three times, and the fringes are mapped into the fixed camera. The geometrical calibration can be accomplished by estimating the pose between the camera and virtual image of fringes. With the help of the relation between their pose, incidence and reflection ray can be unified in the camera frame, forward triangulation intersection can be operated in the camera frame to measure 3D coordinate of specular surface. In the final optimization, constraint bundle adjustment is operated to refine simultaneously the camera intrinsic parameters including distortion coefficients, estimated geometrical pose between LCD screen and camera, 3D coordinate of specular surface, with the help of absolute phase collinear constraint. Results of simulations and experiments demonstrate that the pose calibration with planar mirror reflection is simple, feasible and constraint bundle adjustment can enhance the three-dimensional coordinate measurement accuracy in fringe-reflection photogrammetry.

  9. A Bayesian Framework for Human Body Pose Tracking from Depth Image Sequences

    Directory of Open Access Journals (Sweden)

    Youding Zhu

    2010-05-01

    Full Text Available This paper addresses the problem of accurate and robust tracking of 3D human body pose from depth image sequences. Recovering the large number of degrees of freedom in human body movements from a depth image sequence is challenging due to the need to resolve the depth ambiguity caused by self-occlusions and the difficulty to recover from tracking failure. Human body poses could be estimated through model fitting using dense correspondences between depth data and an articulated human model (local optimization method. Although it usually achieves a high accuracy due to dense correspondences, it may fail to recover from tracking failure. Alternately, human pose may be reconstructed by detecting and tracking human body anatomical landmarks (key-points based on low-level depth image analysis. While this method (key-point based method is robust and recovers from tracking failure, its pose estimation accuracy depends solely on image-based localization accuracy of key-points. To address these limitations, we present a flexible Bayesian framework for integrating pose estimation results obtained by methods based on key-points and local optimization. Experimental results are shown and performance comparison is presented to demonstrate the effectiveness of the proposed approach.

  10. Improving attitudes toward mathematics learning with problem posing in class VIII

    Science.gov (United States)

    Vionita, Alfha; Purboningsih, Dyah

    2017-08-01

    This research is classroom action research which is collaborated to improve student's behavior toward math and mathematics learning at class VIII by using problem posing approach. The subject of research is all of students grade VIIIA which consist of 32 students. This research has been held on two period, first period is about 3 times meeting, and second period is about 4 times meeting. The instrument of this research is implementation of learning observation's guidance by using problem posing approach. Cycle test has been used to measure cognitive competence, and questionnaire to measure the students' behavior in mathematics learning process. The result of research shows the students' behavior has been improving after using problem posing approach. It is showed by the behavior's criteria of students that has increasing result from the average in first period to high in second period. Furthermore, the percentage of test result is also improve from 68,75% in first period to 78,13% in second period. On the other hand, the implementation of learning observation by using problem posing approach has also improving and it is showed by the average percentage of teacher's achievement in first period is 89,2% and student's achievement 85,8%. These results get increase in second period for both teacher and students' achievement which are 94,4% and 91,11%. As a result, students' behavior toward math learning process in class VIII has been improving by using problem posing approach.

  11. Single leg balancing in ballet: effects of shoe conditions and poses.

    Science.gov (United States)

    Lobo da Costa, Paula H; Azevedo Nora, Fernanda G S; Vieira, Marcus Fraga; Bosch, Kerstin; Rosenbaum, Dieter

    2013-03-01

    The purpose of this study was to describe the effects of lower limb positioning and shoe conditions on stability levels of selected single leg ballet poses performed in demi-pointe position. Fourteen female non-professional ballet dancers (mean age of 18.4±2.8 years and mean body mass index of 21.5±2.8kg/m(2)) who had practiced ballet for at least seven years, without any musculoskeletal impairment volunteered to participate in this study. A capacitive pressure platform allowed for the assessment of center of pressure variables related to the execution of three single leg ballet poses in demi pointé position: attitude devant, attitude derriére, and attitude a la second. Peak pressures, contact areas, COP oscillation areas, anterior-posterior and medio-lateral COP oscillations and velocities were compared between two shoe conditions (barefoot versus slippers) and among the different poses. Barefoot performances produced more stable poses with significantly higher plantar contact areas, smaller COP oscillation areas and smaller anterior-posterior COP oscillations. COP oscillation areas, anterior-posterior COP oscillations and medio-lateral COP velocities indicated that attitude a la second is the least challenging and attitude derriére the most challenging pose. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Simulation of the Ill-Posed Problem of Reinforced Concrete Corrosion Detection Using Boundary Element Method

    Directory of Open Access Journals (Sweden)

    Syarizal Fonna

    2016-01-01

    Full Text Available Many studies have suggested that the corrosion detection of reinforced concrete (RC based on electrical potential on concrete surface was an ill-posed problem, and thus it may present an inaccurate interpretation of corrosion. However, it is difficult to prove the ill-posed problem of the RC corrosion detection by experiment. One promising technique is using a numerical method. The objective of this study is to simulate the ill-posed problem of RC corrosion detection based on electrical potential on a concrete surface using the Boundary Element Method (BEM. BEM simulates electrical potential within a concrete domain. In order to simulate the electrical potential, the domain is assumed to be governed by Laplace’s equation. The boundary conditions for the corrosion area and the noncorrosion area of rebar were selected from its polarization curve. A rectangular reinforced concrete model with a single rebar was chosen to be simulated using BEM. The numerical simulation results using BEM showed that the same electrical potential distribution on the concrete surface could be generated from different combinations of parameters. Corresponding to such a phenomenon, this problem can be categorized as an ill-posed problem since it has many solutions. Therefore, BEM successfully simulates the ill-posed problem of reinforced concrete corrosion detection.

  13. Combining in silico and in cerebro approaches for virtual screening and pose prediction in SAMPL4

    Science.gov (United States)

    Voet, Arnout R. D.; Kumar, Ashutosh; Berenger, Francois; Zhang, Kam Y. J.

    2014-04-01

    The SAMPL challenges provide an ideal opportunity for unbiased evaluation and comparison of different approaches used in computational drug design. During the fourth round of this SAMPL challenge, we participated in the virtual screening and binding pose prediction on inhibitors targeting the HIV-1 integrase enzyme. For virtual screening, we used well known and widely used in silico methods combined with personal in cerebro insights and experience. Regular docking only performed slightly better than random selection, but the performance was significantly improved upon incorporation of additional filters based on pharmacophore queries and electrostatic similarities. The best performance was achieved when logical selection was added. For the pose prediction, we utilized a similar consensus approach that amalgamated the results of the Glide-XP docking with structural knowledge and rescoring. The pose prediction results revealed that docking displayed reasonable performance in predicting the binding poses. However, prediction performance can be improved utilizing scientific experience and rescoring approaches. In both the virtual screening and pose prediction challenges, the top performance was achieved by our approaches. Here we describe the methods and strategies used in our approaches and discuss the rationale of their performances.

  14. Inertial measurement unit–based iterative pose compensation algorithm for low-cost modular manipulator

    Directory of Open Access Journals (Sweden)

    Yunhan Lin

    2016-01-01

    Full Text Available It is a necessary mean to realize the accurate motion control of the manipulator which uses end-effector pose correction method and compensation method. In this article, first, we established the kinematic model and error model of the modular manipulator (WUST-ARM, and then we discussed the measurement methods and precision of the inertial measurement unit sensor. The inertial measurement unit sensor is mounted on the end-effector of modular manipulator, to get the real-time pose of the end-effector. At last, a new inertial measurement unit–based iterative pose compensation algorithm is proposed. By applying this algorithm in the pose compensation experiment of modular manipulator which is composed of low-cost rotation joints, the results show that the inertial measurement unit can obtain a higher precision when in static state; it will accurately feedback to the control system with an accurate error compensation angle after a brief delay when the end-effector moves to the target point, and after compensation, the precision errors of roll angle, pitch angle, and yaw angle are reached at 0.05°, 0.01°, and 0.27° respectively. It proves that this low-cost method provides a new solution to improve the end-effector pose of low-cost modular manipulator.

  15. Combining in silico and in cerebro approaches for virtual screening and pose prediction in SAMPL4.

    Science.gov (United States)

    Voet, Arnout R D; Kumar, Ashutosh; Berenger, Francois; Zhang, Kam Y J

    2014-04-01

    The SAMPL challenges provide an ideal opportunity for unbiased evaluation and comparison of different approaches used in computational drug design. During the fourth round of this SAMPL challenge, we participated in the virtual screening and binding pose prediction on inhibitors targeting the HIV-1 integrase enzyme. For virtual screening, we used well known and widely used in silico methods combined with personal in cerebro insights and experience. Regular docking only performed slightly better than random selection, but the performance was significantly improved upon incorporation of additional filters based on pharmacophore queries and electrostatic similarities. The best performance was achieved when logical selection was added. For the pose prediction, we utilized a similar consensus approach that amalgamated the results of the Glide-XP docking with structural knowledge and rescoring. The pose prediction results revealed that docking displayed reasonable performance in predicting the binding poses. However, prediction performance can be improved utilizing scientific experience and rescoring approaches. In both the virtual screening and pose prediction challenges, the top performance was achieved by our approaches. Here we describe the methods and strategies used in our approaches and discuss the rationale of their performances.

  16. A Bayesian Framework for Human Body Pose Tracking from Depth Image Sequences

    Science.gov (United States)

    Zhu, Youding; Fujimura, Kikuo

    2010-01-01

    This paper addresses the problem of accurate and robust tracking of 3D human body pose from depth image sequences. Recovering the large number of degrees of freedom in human body movements from a depth image sequence is challenging due to the need to resolve the depth ambiguity caused by self-occlusions and the difficulty to recover from tracking failure. Human body poses could be estimated through model fitting using dense correspondences between depth data and an articulated human model (local optimization method). Although it usually achieves a high accuracy due to dense correspondences, it may fail to recover from tracking failure. Alternately, human pose may be reconstructed by detecting and tracking human body anatomical landmarks (key-points) based on low-level depth image analysis. While this method (key-point based method) is robust and recovers from tracking failure, its pose estimation accuracy depends solely on image-based localization accuracy of key-points. To address these limitations, we present a flexible Bayesian framework for integrating pose estimation results obtained by methods based on key-points and local optimization. Experimental results are shown and performance comparison is presented to demonstrate the effectiveness of the proposed approach. PMID:22399933

  17. Mobile Robot Aided Silhouette Imaging and Robust Body Pose Recognition for Elderly-Fall Detection

    Directory of Open Access Journals (Sweden)

    Tong Liu

    2014-03-01

    Full Text Available This article introduces a mobile infrared silhouette imaging and sparse representation-based pose recognition for building an elderly-fall detection system. The proposed imaging paradigm exploits the novel use of the pyroelectric infrared (PIR sensor in pursuit of body silhouette imaging. A mobile robot carrying a vertical column of multi-PIR detectors is organized for the silhouette acquisition. Then we express the fall detection problem in silhouette image-based pose recognition. For the pose recognition, we use a robust sparse representation-based method for fall detection. The normal and fall poses are sparsely represented in the basis space spanned by the combinations of a pose training template and an error template. The ℓ1 norm minimizations with linear programming (LP and orthogonal matching pursuit (OMP are used for finding the sparsest solution, and the entity with the largest amplitude encodes the class of the testing sample. The application of the proposed sensing paradigm to fall detection is addressed in the context of three scenarios, including: ideal non-obstruction, simulated random pixel obstruction and simulated random block obstruction. Experimental studies are conducted to validate the effectiveness of the proposed method for nursing and homeland healthcare.

  18. POSE ESTIMATION OF UNMANNED AERIAL VEHICLES BASED ON A VISION-AIDED MULTI-SENSOR FUSION

    Directory of Open Access Journals (Sweden)

    G. Abdi

    2016-06-01

    Full Text Available GNSS/IMU navigation systems offer low-cost and robust solution to navigate UAVs. Since redundant measurements greatly improve the reliability of navigation systems, extensive researches have been made to enhance the efficiency and robustness of GNSS/IMU by additional sensors. This paper presents a method for integrating reference data, images taken from UAVs, barometric height data and GNSS/IMU data to estimate accurate and reliable pose parameters of UAVs. We provide improved pose estimations by integrating multi-sensor observations in an EKF algorithm with IMU motion model. The implemented methodology has demonstrated to be very efficient and reliable for automatic pose estimation. The calculated position and attitude of the UAV especially when we removed the GNSS from the working cycle clearly indicate the ability of the purposed methodology.

  19. Critical steps in camera pose estimation: an evaluation using LTI-LIB2 library

    Directory of Open Access Journals (Sweden)

    Laura Cabrera-Quirós

    2014-03-01

    Full Text Available An evaluation of camera pose estimation methods using a chessboard pattern is presented. Steps evaluated in the estimation process are landmark point detection and camera parameter estimation, due to their critical role in the entire process. The ChESS method and a custom heuristic method are compared for chessboard pattern detection.  Both methods are objectively contrasted using True Positive and False Negative criteria. Meanwhile, Zhang’s method for pose estimation based on planar surface point distribution is used as a first approach, and then refined with a nonlinear regression through the Levenberg-Marquardt algorithm. This pose estimation algorithm is evaluated through a comparison with a stable tool, such as the Camera Calibration Toolbox for Matlab®.

  20. Pose optimization and port placement for robot-assisted minimally invasive surgery in cholecystectomy.

    Science.gov (United States)

    Feng, Mei; Jin, Xingze; Tong, Weihua; Guo, Xiaoyu; Zhao, Ji; Fu, Yili

    2017-12-01

    Pose optimization and port placement are critical issues for preoperative preparation in robot-assisted minimally invasive surgery (RMIS), and affect the robot performance and surgery quality. This paper proposes a method for pose optimization and port placement for RMIS in cholecystectomy that considers both the robot and surgery requirements. The robot pose optimization was divided into optimization of the positioning joint configuration and optimization of the end effector configuration. To determine the optimal location for the trocar port placement, the operational workspace was defined as the evaluation index. The port area was divided into many sub-areas, and that with the maximum operational workspace was selected as the location for the port placement. Considering the left robotic arm as an example, the location for the port placement and joints angles for robotic arm configuration were discussed and simulated using the proposed method. This research can provide guidelines for surgeons in preoperative preparation. Copyright © 2017 John Wiley & Sons, Ltd.

  1. Categorization of questions posed before and after inquiry-based learning

    Directory of Open Access Journals (Sweden)

    Sandra Milena García González

    2014-07-01

    Full Text Available Posing research questions is the central ability of the scientific thought. This article examines the ability of sixth grade children to pose researchable questions before and after a three months’ work on a didactic sequence based on the inquiry school model. According to their purpose, the questions asked by children, after reading a text, were classified into researchable questions -susceptible to be empirically explored-, questions about a cause, and questions on a piece of data. The results show that the amount and the type of questions the students were able to pose during the intervention changed, from most of questions on data or information, to most of researchable questions, subsequently, the importance of designing teaching approaches to foster this ability was proved.

  2. Methods for intraoperative, sterile pose-setting of patient-specific microstereotactic frames

    Science.gov (United States)

    Vollmann, Benjamin; Müller, Samuel; Kundrat, Dennis; Ortmaier, Tobias; Kahrs, Lüder A.

    2015-03-01

    This work proposes new methods for a microstereotactic frame based on bone cement fixation. Microstereotactic frames are under investigation for minimal invasive temporal bone surgery, e.g. cochlear implantation, or for deep brain stimulation, where products are already on the market. The correct pose of the microstereotactic frame is either adjusted outside or inside the operating room and the frame is used for e.g. drill or electrode guidance. We present a patientspecific, disposable frame that allows intraoperative, sterile pose-setting. Key idea of our approach is bone cement between two plates that cures while the plates are positioned with a mechatronics system in the desired pose. This paper includes new designs of microstereotactic frames, a system for alignment and first measurements to analyze accuracy and applicable load.

  3. Structural interface parameters are discriminatory in recognising near-native poses of protein-protein interactions.

    Directory of Open Access Journals (Sweden)

    Sony Malhotra

    Full Text Available Interactions at the molecular level in the cellular environment play a very crucial role in maintaining the physiological functioning of the cell. These molecular interactions exist at varied levels viz. protein-protein interactions, protein-nucleic acid interactions or protein-small molecules interactions. Presently in the field, these interactions and their mechanisms mark intensively studied areas. Molecular interactions can also be studied computationally using the approach named as Molecular Docking. Molecular docking employs search algorithms to predict the possible conformations for interacting partners and then calculates interaction energies. However, docking proposes number of solutions as different docked poses and hence offers a serious challenge to identify the native (or near native structures from the pool of these docked poses. Here, we propose a rigorous scoring scheme called DockScore which can be used to rank the docked poses and identify the best docked pose out of many as proposed by docking algorithm employed. The scoring identifies the optimal interactions between the two protein partners utilising various features of the putative interface like area, short contacts, conservation, spatial clustering and the presence of positively charged and hydrophobic residues. DockScore was first trained on a set of 30 protein-protein complexes to determine the weights for different parameters. Subsequently, we tested the scoring scheme on 30 different protein-protein complexes and native or near-native structure were assigned the top rank from a pool of docked poses in 26 of the tested cases. We tested the ability of DockScore to discriminate likely dimer interactions that differ substantially within a homologous family and also demonstrate that DOCKSCORE can distinguish correct pose for all 10 recent CAPRI targets.

  4. Estimation of Antenna Pose in the Earth Frame Using Camera and IMU Data from Mobile Phones.

    Science.gov (United States)

    Wang, Zhen; Jin, Bingwen; Geng, Weidong

    2017-04-08

    The poses of base station antennas play an important role in cellular network optimization. Existing methods of pose estimation are based on physical measurements performed either by tower climbers or using additional sensors attached to antennas. In this paper, we present a novel non-contact method of antenna pose measurement based on multi-view images of the antenna and inertial measurement unit (IMU) data captured by a mobile phone. Given a known 3D model of the antenna, we first estimate the antenna pose relative to the phone camera from the multi-view images and then employ the corresponding IMU data to transform the pose from the camera coordinate frame into the Earth coordinate frame. To enhance the resulting accuracy, we improve existing camera-IMU calibration models by introducing additional degrees of freedom between the IMU sensors and defining a new error metric based on both the downtilt and azimuth angles, instead of a unified rotational error metric, to refine the calibration. In comparison with existing camera-IMU calibration methods, our method achieves an improvement in azimuth accuracy of approximately 1.0 degree on average while maintaining the same level of downtilt accuracy. For the pose estimation in the camera coordinate frame, we propose an automatic method of initializing the optimization solver and generating bounding constraints on the resulting pose to achieve better accuracy. With this initialization, state-of-the-art visual pose estimation methods yield satisfactory results in more than 75% of cases when plugged into our pipeline, and our solution, which takes advantage of the constraints, achieves even lower estimation errors on the downtilt and azimuth angles, both on average (0.13 and 0.3 degrees lower, respectively) and in the worst case (0.15 and 7.3 degrees lower, respectively), according to an evaluation conducted on a dataset consisting of 65 groups of data. We show that both of our enhancements contribute to the performance

  5. Robustness of Input features from Noisy Silhouettes in Human Pose Estimation

    DEFF Research Database (Denmark)

    Gong, Wenjuan; Fihl, Preben; Gonzàlez, Jordi

    2014-01-01

    . In this paper, we explore this problem. First, We compare performances of several image features widely used for human pose estimation and explore their performances against each other and select one with best performance. Second, iterative closest point algorithm is introduced for a new quantitative...... measurement of noisy inputs. The proposed measurement is able to automatically discard noise, like camouflage from the background or shadows. With the proposed measurement, we split inputs into different noise levels and assess their pose estimation accuracies. Furthermore, we explore performances...

  6. El cuerpo poseído como una forma de cuerpo sin órganos

    OpenAIRE

    Germán Prósperi

    2005-01-01

    El principal objetivo de este trabajo consiste en relacionar el concepto deleuziano de "cuerpo sin órganos" con el análisis que realiza Foucault, en Los anormales, del cuerpo poseído. Concretamente se intentará mostrar cómo es posible concebir al cuerpo poseído de Foucault como un cuerpo sin órganos deleuziano. El trabajo girará alrededor de tres grandes ejes: el organismo y el campo de intervención; la significancia y el dominio discursivo; la subjetivación y el saber. Finalmente se menciona...

  7. Simultaneous Estimation of Material Properties and Pose for Deformable Objects from Depth and Color Images

    DEFF Research Database (Denmark)

    Fugl, Andreas Rune; Jordt, Andreas; Petersen, Henrik Gordon

    2012-01-01

    In this paper we consider the problem of estimating 6D pose and material properties of a deformable object grasped by a robot grip- per. To estimate the parameters we minimize an error function incorpo- rating visual and physical correctness. Through simulated and real-world experiments we...... demonstrate that we are able to find realistic 6D poses and elasticity parameters like Young’s modulus. This makes it possible to perform subsequent manipulation tasks, where accurate modelling of the elastic behaviour is important....

  8. Estimation of Antenna Pose in the Earth Frame Using Camera and IMU Data from Mobile Phones

    Science.gov (United States)

    Wang, Zhen; Jin, Bingwen; Geng, Weidong

    2017-01-01

    The poses of base station antennas play an important role in cellular network optimization. Existing methods of pose estimation are based on physical measurements performed either by tower climbers or using additional sensors attached to antennas. In this paper, we present a novel non-contact method of antenna pose measurement based on multi-view images of the antenna and inertial measurement unit (IMU) data captured by a mobile phone. Given a known 3D model of the antenna, we first estimate the antenna pose relative to the phone camera from the multi-view images and then employ the corresponding IMU data to transform the pose from the camera coordinate frame into the Earth coordinate frame. To enhance the resulting accuracy, we improve existing camera-IMU calibration models by introducing additional degrees of freedom between the IMU sensors and defining a new error metric based on both the downtilt and azimuth angles, instead of a unified rotational error metric, to refine the calibration. In comparison with existing camera-IMU calibration methods, our method achieves an improvement in azimuth accuracy of approximately 1.0 degree on average while maintaining the same level of downtilt accuracy. For the pose estimation in the camera coordinate frame, we propose an automatic method of initializing the optimization solver and generating bounding constraints on the resulting pose to achieve better accuracy. With this initialization, state-of-the-art visual pose estimation methods yield satisfactory results in more than 75% of cases when plugged into our pipeline, and our solution, which takes advantage of the constraints, achieves even lower estimation errors on the downtilt and azimuth angles, both on average (0.13 and 0.3 degrees lower, respectively) and in the worst case (0.15 and 7.3 degrees lower, respectively), according to an evaluation conducted on a dataset consisting of 65 groups of data. We show that both of our enhancements contribute to the performance

  9. Inertial measurement unit–based iterative pose compensation algorithm for low-cost modular manipulator

    OpenAIRE

    Yunhan Lin; Huasong Min; Hongxing Wei

    2016-01-01

    It is a necessary mean to realize the accurate motion control of the manipulator which uses end-effector pose correction method and compensation method. In this article, first, we established the kinematic model and error model of the modular manipulator (WUST-ARM), and then we discussed the measurement methods and precision of the inertial measurement unit sensor. The inertial measurement unit sensor is mounted on the end-effector of modular manipulator, to get the real-time pose of the end-...

  10. Importance of hydrophobic parameters in identifying appropriate pose of CYP substrates in cytochromes.

    Science.gov (United States)

    Ramesh, M; Bharatam, Prasad V

    2014-01-01

    Cytochromes are catalytic enzymes which perform oxidative metabolic reactions on drugs. To determine the primary binding forces of CYP-substrate complex, molecular docking studies were carried out. Molecular docking analysis of several drugs with the enzymes CYP2C9, CYP2D6 and CYP3A4 revealed that hydrophobic interactions play a major role in determining the pose selection between substrates and enzymes. GOLD software with hydrophobic and hydrogen bond constraint was employed to identify the specific interactions which play deterministic role in the pose selection. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  11. Real-Time Biologically Inspired Action Recognition from Key Poses Using a Neuromorphic Architecture.

    Science.gov (United States)

    Layher, Georg; Brosch, Tobias; Neumann, Heiko

    2017-01-01

    Intelligent agents, such as robots, have to serve a multitude of autonomous functions. Examples are, e.g., collision avoidance, navigation and route planning, active sensing of its environment, or the interaction and non-verbal communication with people in the extended reach space. Here, we focus on the recognition of the action of a human agent based on a biologically inspired visual architecture of analyzing articulated movements. The proposed processing architecture builds upon coarsely segregated streams of sensory processing along different pathways which separately process form and motion information (Layher et al., 2014). Action recognition is performed in an event-based scheme by identifying representations of characteristic pose configurations (key poses) in an image sequence. In line with perceptual studies, key poses are selected unsupervised utilizing a feature-driven criterion which combines extrema in the motion energy with the horizontal and the vertical extendedness of a body shape. Per class representations of key pose frames are learned using a deep convolutional neural network consisting of 15 convolutional layers. The network is trained using the energy-efficient deep neuromorphic networks ( Eedn ) framework (Esser et al., 2016), which realizes the mapping of the trained synaptic weights onto the IBM Neurosynaptic System platform (Merolla et al., 2014). After the mapping, the trained network achieves real-time capabilities for processing input streams and classify input images at about 1,000 frames per second while the computational stages only consume about 70 mW of energy (without spike transduction). Particularly regarding mobile robotic systems, a low energy profile might be crucial in a variety of application scenarios. Cross-validation results are reported for two different datasets and compared to state-of-the-art action recognition approaches. The results demonstrate, that (I) the presented approach is on par with other key pose based

  12. Pose Estimation using a Hierarchical 3D Representation of Contours and Surfaces

    DEFF Research Database (Denmark)

    Buch, Anders Glent; Kraft, Dirk; Kämäräinen, Joni-Kristian

    2013-01-01

    We present a system for detecting the pose of rigid objects using texture and contour information. From a stereo image view of a scene, a sparse hierarchical scene representation is reconstructed using an early cognitive vision system. We define an object model in terms of a simple context...... descriptor of the contour and texture features to provide a sparse, yet descriptive object representation. Using our descriptors, we do a search in the correspondence space to perform outlier removal and compute the object pose. We perform an extensive evaluation of our approach with stereo images...

  13. Real-Time Biologically Inspired Action Recognition from Key Poses Using a Neuromorphic Architecture

    Science.gov (United States)

    Layher, Georg; Brosch, Tobias; Neumann, Heiko

    2017-01-01

    Intelligent agents, such as robots, have to serve a multitude of autonomous functions. Examples are, e.g., collision avoidance, navigation and route planning, active sensing of its environment, or the interaction and non-verbal communication with people in the extended reach space. Here, we focus on the recognition of the action of a human agent based on a biologically inspired visual architecture of analyzing articulated movements. The proposed processing architecture builds upon coarsely segregated streams of sensory processing along different pathways which separately process form and motion information (Layher et al., 2014). Action recognition is performed in an event-based scheme by identifying representations of characteristic pose configurations (key poses) in an image sequence. In line with perceptual studies, key poses are selected unsupervised utilizing a feature-driven criterion which combines extrema in the motion energy with the horizontal and the vertical extendedness of a body shape. Per class representations of key pose frames are learned using a deep convolutional neural network consisting of 15 convolutional layers. The network is trained using the energy-efficient deep neuromorphic networks (Eedn) framework (Esser et al., 2016), which realizes the mapping of the trained synaptic weights onto the IBM Neurosynaptic System platform (Merolla et al., 2014). After the mapping, the trained network achieves real-time capabilities for processing input streams and classify input images at about 1,000 frames per second while the computational stages only consume about 70 mW of energy (without spike transduction). Particularly regarding mobile robotic systems, a low energy profile might be crucial in a variety of application scenarios. Cross-validation results are reported for two different datasets and compared to state-of-the-art action recognition approaches. The results demonstrate, that (I) the presented approach is on par with other key pose based

  14. Riccati equations for stable well-posed linear systems : The generic case

    NARCIS (Netherlands)

    Curtain, RF

    2003-01-01

    Under the generic assumption that zero is in the resolvent set of the generator, we show that the optimal control problem for a stable well-posed linear system is equivalent to a control problem for its reciprocal system which has bounded generating operators. Consequently, the operator X that

  15. An Error Analysis in Division Problems in Fractions Posed by Pre-Service Elementary Mathematics Teachers

    Science.gov (United States)

    Isik, Cemalettin; Kar, Tugrul

    2012-01-01

    The present study aimed to make an error analysis in the problems posed by pre-service elementary mathematics teachers about fractional division operation. It was carried out with 64 pre-service teachers studying in their final year in the Department of Mathematics Teaching in an eastern university during the spring semester of academic year…

  16. Human Pose Estimation from Silhouettes. A Consistent Approach Using Distance Level Sets

    NARCIS (Netherlands)

    Sminchisescu, C.; Telea, A.

    2002-01-01

    We present a novel similarity measure (likelihood) for estimating three-dimensional human pose from image silhouettes in model-based vision applications. One of the challenges in such approaches is the construction of a model-to-image likelihood that truly reflects the good configurations of the

  17. An Improved Method of Pose Estimation for Lighthouse Base Station Extension

    Directory of Open Access Journals (Sweden)

    Yi Yang

    2017-10-01

    Full Text Available In 2015, HTC and Valve launched a virtual reality headset empowered with Lighthouse, the cutting-edge space positioning technology. Although Lighthouse is superior in terms of accuracy, latency and refresh rate, its algorithms do not support base station expansion, and is flawed concerning occlusion in moving targets, that is, it is unable to calculate their poses with a small set of sensors, resulting in the loss of optical tracking data. In view of these problems, this paper proposes an improved pose estimation algorithm for cases where occlusion is involved. Our algorithm calculates the pose of a given object with a unified dataset comprising of inputs from sensors recognized by all base stations, as long as three or more sensors detect a signal in total, no matter from which base station. To verify our algorithm, HTC official base stations and autonomous developed receivers are used for prototyping. The experiment result shows that our pose calculation algorithm can achieve precise positioning when a few sensors detect the signal.

  18. Perturbation-Based Regularization for Signal Estimation in Linear Discrete Ill-posed Problems

    KAUST Repository

    Suliman, Mohamed Abdalla Elhag

    2016-11-29

    Estimating the values of unknown parameters from corrupted measured data faces a lot of challenges in ill-posed problems. In such problems, many fundamental estimation methods fail to provide a meaningful stabilized solution. In this work, we propose a new regularization approach and a new regularization parameter selection approach for linear least-squares discrete ill-posed problems. The proposed approach is based on enhancing the singular-value structure of the ill-posed model matrix to acquire a better solution. Unlike many other regularization algorithms that seek to minimize the estimated data error, the proposed approach is developed to minimize the mean-squared error of the estimator which is the objective in many typical estimation scenarios. The performance of the proposed approach is demonstrated by applying it to a large set of real-world discrete ill-posed problems. Simulation results demonstrate that the proposed approach outperforms a set of benchmark regularization methods in most cases. In addition, the approach also enjoys the lowest runtime and offers the highest level of robustness amongst all the tested benchmark regularization methods.

  19. Morozov-type discrepancy principle for nonlinear ill-posed problems ...

    Indian Academy of Sciences (India)

    close to a linear operator in a restricted sense. A seemingly natural nonlinear assump- tion which appears in many applications which attracted attention in various ... Tikhonov regularization; nonlinear ill-posed problems; discrepancy principle; η-condition. Mathematics Subject Classification. 65M30; 65J20; 35R30. 1.

  20. Detecting Probable Cheating during Online Assessments Based on Time Delay and Head Pose

    Science.gov (United States)

    Chuang, Chia Yuan; Craig, Scotty D.; Femiani, John

    2017-01-01

    This study investigated the ability of test takers' behaviors during online assessments to detect probable cheating incidents. Specifically, this study focused on the role of time delay and head pose for detection of cheating incidences in a lab-based online testing session. The analysis of a test taker's behavior indicated that not only time…

  1. Problem Posing of High School Mathematics Student’s Based on Their Cognitive Style

    Directory of Open Access Journals (Sweden)

    Abdul Rahman

    2017-03-01

    Full Text Available Mathematical problem posing plays an important role in mathematics curriculum, since it encompasses the core of mathematics activities, among other things, with students’ activities to construct their own problems as the preliminary step to actual problem solving steps. This study aims at revealing the profile of students’ mathematical problem posing based on their cognitive styles in order to know and understand the learning of mathematics students. As a result of this study, students who have the cognitive style ‘field independent’ (FI are able to propose a solvable mathematical problem and load new data, and also pose problems categorized as high-quality mathematical problems. Students who have the cognitive style of ‘field dependent’ (FD are generally limited to solvable mathematical problems that do not contain new data, and mathematical problems of a moderate level. In this study, it is seen how student’s work mathematical problem posing using their cognitive style, resulting in a breakthrough in the process of learning to use students’ cognitive styles so as to increase the quality of learning outcomes.

  2. Pose Estimation using Local Structure-Specific Shape and Appearance Context

    DEFF Research Database (Denmark)

    Buch, Anders Glent; Kraft, Dirk; Kämäräinen, Joni-Kristian

    2013-01-01

    We address the problem of estimating the alignment pose between two models using structure-specific local descriptors. Our descriptors are generated using a combination of 2D image data and 3D contextual shape data, resulting in a set of semi-local descriptors containing rich appearance and shape...

  3. Real-time camera pose estimation for wide-area augmented reality applications.

    Science.gov (United States)

    Tao Guan; Liya Duan; Junqing Yu; Yongjian Chen; Xu Zhang

    2011-01-01

    Achieving accurate registration between real and synthetic worlds is one of augmented reality's biggest challenges. A real-time camera-pose estimation method, based on multiple maps and local bundle adjustment, enables the registration to work without prior knowledge of natural scenes. This method can significantly enhance AR systems' usability.

  4. An Investigation of Pattern Problems Posed by Middle School Mathematics Preservice Teachers Using Multiple Representation

    Science.gov (United States)

    Yilmaz, Yasemin; Durmus, Soner; Yaman, Hakan

    2018-01-01

    This study investigated the pattern problems posed by middle school mathematics preservice teachers using multiple representations to determine both their pattern knowledge levels and their abilities to transfer this knowledge to students. The design of the study is the survey method, one of the quantitative research methods. The study group was…

  5. Web-based Visualisation of Head Pose and Facial Expressions Changes:

    DEFF Research Database (Denmark)

    Kalliatakis, Grigorios; Vidakis, Nikolaos; Triantafyllidis, Georgios

    2016-01-01

    and accurately estimate head pose changes in unconstrained environment. In order to complete the secondary process of recognising four universal dominant facial expressions (happiness, anger, sadness and surprise), emotion recognition via facial expressions (ERFE) was adopted. After that, a lightweight data...

  6. Development of a Mobile Learning System Based on a Collaborative Problem-Posing Strategy

    Science.gov (United States)

    Sung, Han-Yu; Hwang, Gwo-Jen; Chang, Ya-Chi

    2016-01-01

    In this study, a problem-posing strategy is proposed for supporting collaborative mobile learning activities. Accordingly, a mobile learning environment has been developed, and an experiment on a local culture course has been conducted to evaluate the effectiveness of the proposed approach. Three classes of an elementary school in southern Taiwan…

  7. Teach it Yourself - Fast Modeling of Industrial Objects for 6D Pose Estimation

    DEFF Research Database (Denmark)

    Sølund, Thomas; Rajeeth Savarimuthu, Thiusius; Glent Buch, Anders

    2015-01-01

    In this paper, we present a vision system that allows a human to create new 3D models of novel industrial parts by placing the part in two different positions in the scene. The two shot modeling framework generates models with a precision that allows the model to be used for 6D pose estimation...

  8. A problem-posing approach to teaching the topic of radioactivity

    NARCIS (Netherlands)

    Klaassen, C.W.J.M.

    1995-01-01

    This thesis highlights a problem-posing approach to science education. By this is meant an approach that explicitly aims at providing students with content-related motives for extending their existing conceptual resources, experiential base and belief system in a certain direction, such that a

  9. Utilizing Semantic Interpretation of Junctions for 3D-2D Pose Estimation

    DEFF Research Database (Denmark)

    Pilz, Florian; Yan, Shi; Grest, Daniel

    2007-01-01

    In this paper we investigate the quality of 3D-2D pose estimates using hand labeled line and point correspondences. We select point correspondences from junctions in the image, allowing to construct a meaningful interpretation about how the junction is formed, as proposed in e.g. [1], [2], [3]. W...

  10. A Comparison of Iterative 2D-3D Pose Estimation Methods for Real-Time Applications

    DEFF Research Database (Denmark)

    Grest, Daniel; Krüger, Volker; Petersen, Thomas

    2009-01-01

    This work compares iterative 2D-3D Pose Estimation methods for use in real-time applications. The compared methods are available for public as C++ code. One method is part of the openCV library, namely POSIT. Because POSIT is not applicable for planar 3Dpoint congurations, we include the planar P...

  11. Callous-Unemotional Traits Are Related to Combined Deficits in Recognizing Afraid Faces and Body Poses

    Science.gov (United States)

    Munoz, Luna C.

    2009-01-01

    Results from a study that involves letting boys aged 8-16 years label emotional faces and static body poses show that callous-unemotional traits are related to poor accuracy in the tests. The results imply that a general "fear-blindness" is associated to a lack of empathy and to violence and antisocial behavior.

  12. STS-33 MS Musgrave, wearing headset, poses on Discovery's, OV-103's, middeck

    Science.gov (United States)

    1989-01-01

    STS-33 Mission Specialist (MS) F. Story Musgrave, wearing comunications kit assembly headset and light blue flight coveralls, poses on Discovery's, Orbiter Vehicle (OV) 103's, middeck. Behind Musgrave on the starboard wall are the sleep restraints, a camera, and a camera mounting bracket.

  13. Multilayer Joint Gait-Pose Manifolds for Human Gait Motion Modeling.

    Science.gov (United States)

    Ding, Meng; Fan, Guolian

    2015-11-01

    We present new multilayer joint gait-pose manifolds (multilayer JGPMs) for complex human gait motion modeling, where three latent variables are defined jointly in a low-dimensional manifold to represent a variety of body configurations. Specifically, the pose variable (along the pose manifold) denotes a specific stage in a walking cycle; the gait variable (along the gait manifold) represents different walking styles; and the linear scale variable characterizes the maximum stride in a walking cycle. We discuss two kinds of topological priors for coupling the pose and gait manifolds, i.e., cylindrical and toroidal, to examine their effectiveness and suitability for motion modeling. We resort to a topologically-constrained Gaussian process (GP) latent variable model to learn the multilayer JGPMs where two new techniques are introduced to facilitate model learning under limited training data. First is training data diversification that creates a set of simulated motion data with different strides. Second is the topology-aware local learning to speed up model learning by taking advantage of the local topological structure. The experimental results on the Carnegie Mellon University motion capture data demonstrate the advantages of our proposed multilayer models over several existing GP-based motion models in terms of the overall performance of human gait motion modeling.

  14. The Analysis of the Problems the Pre-Service Teachers Experience in Posing Problems about Equations

    Science.gov (United States)

    Isik, Cemalettin; Kar, Tugrul

    2012-01-01

    The present study aimed to analyse the potential difficulties in the problems posed by pre-service teachers about first degree equations with one unknown and equation pairs with two unknowns. It was carried out with 20 pre-service teachers studying in the Department of Elementary Mathematics Educations at a university in Eastern Turkey. The…

  15. Spectral approximation of variationally-posed eigenvalue problems by nonconforming methods

    Science.gov (United States)

    Alonso, Ana; Dello Russo, Anahí

    2009-01-01

    This paper deals with the nonconforming spectral approximation of variationally posed eigenvalue problems. It is an extension to more general situations of known previous results about nonconforming methods. As an application of the present theory, convergence and optimal order error estimates are proved for the lowest order Crouzeix-Raviart approximation of the eigenpairs of two representative second-order elliptical operators.

  16. An Improved Method of Pose Estimation for Lighthouse Base Station Extension.

    Science.gov (United States)

    Yang, Yi; Weng, Dongdong; Li, Dong; Xun, Hang

    2017-10-22

    In 2015, HTC and Valve launched a virtual reality headset empowered with Lighthouse, the cutting-edge space positioning technology. Although Lighthouse is superior in terms of accuracy, latency and refresh rate, its algorithms do not support base station expansion, and is flawed concerning occlusion in moving targets, that is, it is unable to calculate their poses with a small set of sensors, resulting in the loss of optical tracking data. In view of these problems, this paper proposes an improved pose estimation algorithm for cases where occlusion is involved. Our algorithm calculates the pose of a given object with a unified dataset comprising of inputs from sensors recognized by all base stations, as long as three or more sensors detect a signal in total, no matter from which base station. To verify our algorithm, HTC official base stations and autonomous developed receivers are used for prototyping. The experiment result shows that our pose calculation algorithm can achieve precise positioning when a few sensors detect the signal.

  17. Robust Pose Estimation using the SwissRanger SR-3000 Camera

    DEFF Research Database (Denmark)

    Gudmundsson, Sigurjon Arni; Larsen, Rasmus; Ersbøll, Bjarne Kjær

    2007-01-01

    In this paper a robust method is presented to classify and estimate an objects pose from a real time range image and a low dimensional model. The model is made from a range image training set which is reduced dimensionally by a nonlinear manifold learning method named Local Linear Embedding (LLE)...

  18. Predictors of incident tuberculosis in HiV-exPosed cHildren in tanzania

    African Journals Online (AJOL)

    2012-06-06

    Jun 6, 2012 ... Nutrition, Epidemiology and Global Health and Population, Harvard School of Public Health, Boston, MA. Request for reprints to: Dr. J. L. Finkelstein, Division of Nutritional Sciences, Cornell University, Ithaca, New York,. 14853. Predictors of incident tuberculosis in HiV-exPosed cHildren in tanzania.

  19. Unintended allergens in precautionary labelled and unlabelled products pose significant risks to UK allergic consumers

    NARCIS (Netherlands)

    Remington, B.C.; Baumert, J.L.; Blom, W.M.; Houben, G.F.; Taylor, S.L.; Kruizinga, A.G.

    2015-01-01

    Background Allergens in food may pose a risk to allergic consumers. While there is EU regulation for allergens present as an ingredient, this is not the case for unintended allergen presence (UAP). Food companies use precautionary allergen labels to inform allergic individuals of a potential risk

  20. Nonlinear regularization methods for ill-posed problems with piecewise constant or strongly varying solutions

    Science.gov (United States)

    Egger, H.; Leitão, A.

    2009-11-01

    In this paper we consider nonlinear ill-posed problems with piecewise constant or strongly varying solutions. A class of nonlinear regularization methods is proposed, in which smooth approximations to the Heavyside function are used to reparameterize functions in the solution space by an auxiliary function of levelset type. The analysis of the resulting regularization methods is carried out in two steps: first, we interpret the algorithms as nonlinear regularization methods for recovering the auxiliary function. This allows us to apply standard results from regularization theory, and we prove convergence of regularized approximations for the auxiliary function; additionally, we obtain the convergence of the regularized solutions, which are obtained from the auxiliary function by the nonlinear transformation. Second, we analyze the proposed methods as approximations to the levelset regularization method analyzed in [Frühauf F, Scherzer O and Leitão A 2005 Analysis of regularization methods for the solution of ill-posed problems involving discontinuous operators SIAM J. Numer. Anal. 43 767-86], which follows as a limit case when the smooth functions used for the nonlinear transformations converge to the Heavyside function. For illustration, we consider the application of the proposed algorithms to elliptic Cauchy problems, which are known to be severely ill-posed, and typically allow only for limited reconstructions. Our numerical examples demonstrate that the proposed methods provide accurate reconstructions of piecewise constant solutions also for these severely ill-posed benchmark problems.

  1. Towards real-time body pose estimation for presenters in meeting environments

    NARCIS (Netherlands)

    Poppe, Ronald Walter; Heylen, Dirk K.J.; Nijholt, Antinus; Poel, Mannes

    2005-01-01

    This paper describes a computer vision-based approach to body pose estimation. The algorithm can be executed in real-time and processes low resolution, monocular image sequences. A silhouette is extracted and matched against a projection of a 16 DOF human body model. In addition, skin color is used

  2. Posing the historical Jesus question and the goal of African biblical ...

    African Journals Online (AJOL)

    Using the historical Jesus research method, the aim of this paper is to pose the Historical Jesus question in Africa and to enumerate the goal of African Biblical scholarship. The study showed that while the first quest sought to reconstruct the biography of Jesus from the New Testament materials in the 19th century and ...

  3. Using Online Modelled Spatial Constraints for Pose Estimation in an Industrial Setting

    DEFF Research Database (Denmark)

    Meyer, Kenneth Korsgaard; Wolniakowski, Adam; Hagelskjær, Frederik

    2017-01-01

    We introduce a vision system that is able to on-line learn spatial constraints to improve pose estimation in terms of correct recognition as well as computational speed. By making use of a simulated industrial robot system performing various pick and place tasks, we show the effect of model...

  4. Pose Measurement Method and Experiments for High-Speed Rolling Targets in a Wind Tunnel

    Directory of Open Access Journals (Sweden)

    Zhenyuan Jia

    2014-12-01

    Full Text Available High-precision wind tunnel simulation tests play an important role in aircraft design and manufacture. In this study, a high-speed pose vision measurement method is proposed for high-speed and rolling targets in a supersonic wind tunnel. To obtain images with high signal-to-noise ratio and avoid impacts on the aerodynamic shape of the rolling targets, a high-speed image acquisition method based on ultrathin retro-reflection markers is presented. Since markers are small-sized and some of them may be lost when the target is rolling, a novel markers layout with which markers are distributed evenly on the surface is proposed based on a spatial coding method to achieve highly accurate pose information. Additionally, a pose acquisition is carried out according to the mentioned markers layout after removing mismatching points by Case Deletion Diagnostics. Finally, experiments on measuring the pose parameters of high-speed targets in the laboratory and in a supersonic wind tunnel are conducted to verify the feasibility and effectiveness of the proposed method. Experimental results indicate that the position measurement precision is less than 0.16 mm, the pitching and yaw angle precision less than 0.132° and the roll angle precision 0.712°.

  5. In this section of Resonance, we invite readers to pose questions ...

    Indian Academy of Sciences (India)

    Admin

    In this section of Resonance, we invite readers to pose questions likely to be raised in a classroom situation. We may suggest strategies for dealing with them, or invite responses, or both. “Classroom” is equally a forum for raising broader issues and sharing personal experiences and viewpoints on matters related to ...

  6. Testing a Comprehensive Model for Measuring Problem Solving and Problem Posing Skills of Primary Pupils

    Science.gov (United States)

    Charalambous, Charalambos; Kyriakides, Leonidas; Philippou, George

    2003-01-01

    The study reported in this paper is an attempt to develop a comprehensive model of measuring problem solving and posing (PSP) skills based on Marshall's schema theory (ST). A battery of tests on PSP skills was administered to 5th and 6th grade Cypriot students (n=2519). The Rasch model was used and a scale was created for the battery of tests and…

  7. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18 Section 740.18 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS Warning Statements § 740.18 Coal tar hair dyes...

  8. Surgical fiducial segmentation and tracking for pose estimation based on ultrasound B-mode images.

    Science.gov (United States)

    Lei Chen; Kuo, Nathanael; Aalamifar, Fereshteh; Narrow, David; Coon, Devin; Prince, Jerry; Boctor, Emad M

    2016-08-01

    Doppler ultrasound is a non-invasive diagnostic tool for the quantitative measurement of blood flow. However, given that it provides velocity data that is dependent on the location and angle of measurement, repeat measurements to detect problems over time may require an expert to return to the same location. We therefore developed an image-guidance system based on ultrasound B-mode images that enables an inexperienced user to position the ultrasound probe at the same site repeatedly in order to acquire a comparable time series of Doppler readings. The system utilizes a bioresorbable fiducial and complementing software composed of the fiducial detection, key points tracking, probe pose estimation, and graphical user interface (GUI) modules. The fiducial is an echogenic marker that is implanted at the surgical site and can be detected and tracked during ultrasound B-mode screening. The key points on the marker can next be used to determine the pose of the ultrasound probe with respect to the marker. The 3D representation of the probe with its position and orientation are then displayed in the GUI for the user guidance. The fiducial detection has been tested on the data sets collected from three animal studies. The pose estimation algorithm was validated by five data sets collected by a UR5 robot. We tested the system on a plastisol phantom and showed that it can detect and track the fiducial marker while displaying the probe pose in real-time.

  9. EFEKTIVITAS METODE PROBLEM POSING BERBANTUAN MEDIA PREZI UNTUK MENINGKATKAN HASIL BELAJAR SISWA MATERI JURNAL PENYESUAIAN

    Directory of Open Access Journals (Sweden)

    Kharisma Puspita Dewi

    2016-02-01

    Full Text Available Tujuan penelitian ini yaitu untuk mengetahui apakah metode problem posing berbantuan media prezi dapat meningkatkan hasil belajar dan lebih efektif dibandingkan metode ceramah pada materi jurnal penyesuaian. Penelitian ini menggunakan metode quasi experiment dengan pola nonequivalent control group design. Populasi dalam penelitian ini adalah seluruh siswa kelas XI IPS di SMA N 1 Padamara Kabupaten Purbalingga tahun pelajaran 2014/2015. Sampel penelitian dipilih secara cluster random sampling yang kemudian diperoleh kelas XI IPS 3 sebagai kelas eksperimen dan XI IPS 4 sebagai kelas kontrol. Metode pengumpulan data yaitu dokumentasi, tes, observasi. Pengujian H1 yaitu menggunakan uji paired sample t-test dan H2 menggunakan uji independent sample t-test. Hasil uji menunjukkan adanya peningkatan hasil belajar setelah adanya perlakuan. Kemudian dari hasil uji menunjukkan bahwa metode problem posing berbantuan media prezi lebih efektif dibandingkan metode ceramah. Oleh karena itu, guru disarankan unuk menggunakan metode problem posing berbantuan media prezi pada materi jurnal penyesuaian atau pada materi lain. Pihak sekolah juga disarankan untuk mengadakan pelatihan bagi guru mengenai penggunaan media prezi.. The purposes of this study were to find out whether implementing problem posing method by using prezi media could improve learning achievement and to find out whether implementing problem posing method by using prezi media was more effective than by using lecture method in adjusting journal subject. This study conducted a quasi-experimental design (nonequivalent control group design. The population of the study was all students of XI IPS in SMA N 1 Padamara, the regency of Purbalingga, in the academic year of 2014/2015. The sample of this study was selected by using cluster random sampling. Students of class XI IPS 3 were chosen as the experimental group and students of class XI IPS 4 were chosen as the control group. The methods of collecting

  10. The biomechanical demands of standing yoga poses in seniors: The Yoga empowers seniors study (YESS

    Directory of Open Access Journals (Sweden)

    Wang Man-Ying

    2013-01-01

    Full Text Available Abstract Background The number of older adults participating in yoga has increased dramatically in recent years; yet, the physical demands associated with yoga performance have not been reported. The primary aim of the Yoga Empowers Seniors Study (YESS was to use biomechanical methods to quantify the physical demands associated with the performance of 7 commonly-practiced standing yoga poses in older adults. Methods 20 ambulatory older adults (70.7 + − 3.8 yrs attended 2 weekly 60-minute Hatha yoga classes for 32 weeks. The lower-extremity net joint moments of force (JMOFs, were obtained during the performance of the following poses: Chair, Wall Plank, Tree, Warrior II, Side Stretch, Crescent, and One-Legged Balance. Repeated-measure ANOVA and Tukey’s post-hoc tests were used to identify differences in JMOFs among the poses. Electromyographic analysis was used to support the JMOF findings. Results There was a significant main effect for pose, at the ankle, knee and hip, in the frontal and sagittal planes (p = 0.00 – 0.03. The Crescent, Chair, Warrior II, and One-legged Balance poses generated the greatest average support moments. Side Stretch generated the greatest average hip extensor and knee flexor JMOFs. Crescent placed the highest demands on the hip flexors and knee extensors. All of the poses produced ankle plantar-flexor JMOFs. In the frontal plane, the Tree generated the greatest average hip and knee abductor JMOFs; whereas Warrior II generated the greatest average hip and knee adductor JMOFs. Warrior II and One-legged Balance induced the largest average ankle evertor and invertor JMOFs, respectively. The electromyographic findings were consistent with the JMOF results. Conclusions Musculoskeletal demand varied significantly across the different poses. These findings may be used to guide the design of evidence-based yoga interventions that address individual-specific training and rehabilitation goals in seniors

  11. An evaluation of 3D head pose estimation using the Microsoft Kinect v2.

    Science.gov (United States)

    Darby, John; Sánchez, María B; Butler, Penelope B; Loram, Ian D

    2016-07-01

    The Kinect v2 sensor supports real-time non-invasive 3D head pose estimation. Because the sensor is small, widely available and relatively cheap it has great potential as a tool for groups interested in measuring head posture. In this paper we compare the Kinect's head pose estimates with a marker-based record of ground truth in order to establish its accuracy. During movement of the head and neck alone (with static torso), we find average errors in absolute yaw, pitch and roll angles of 2.0±1.2°, 7.3±3.2° and 2.6±0.7°, and in rotations relative to the rest pose of 1.4±0.5°, 2.1±0.4° and 2.0±0.8°. Larger head rotations where it becomes difficult to see facial features can cause estimation to fail (10.2±6.1% of all poses in our static torso range of motion tests) but we found no significant changes in performance with the participant standing further away from Kinect - additionally enabling full-body pose estimation - or without performing face shape calibration, something which is not always possible for younger or disabled participants. Where facial features remain visible, the sensor has applications in the non-invasive assessment of postural control, e.g. during a programme of physical therapy. In particular, a multi-Kinect setup covering the full range of head (and body) movement would appear to be a promising way forward. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. The rarity of "unusual" [corrected] dispositions of victim bodies: staging and posing.

    Science.gov (United States)

    Keppel, Robert D; Weis, Joseph G

    2004-11-01

    The act of leaving a victim's body in an unusual position is a conscious criminal action by an offender to thwart an investigation, shock the finder and investigators of the crime scene, or give perverted pleasure to the killer. The unusual position concepts of posing and staging a murder victim have been documented thoroughly and have been accepted by the courts as a definable phenomenon. One staging case and one posing case are outlined and reveal characteristics of those homicides. From the Washington State Attorney General's Homicide Investigation and Tracking System's database on murder covering the years 1981-2000 (a total of 5,224 cases), the relative frequency of unusual body dispositions is revealed as a very rare occurrence. Only 1.3% of victims are left in an unusual position, with 0.3% being posed and 0.1% being staged. The characteristics of these types of murders also set them apart: compared to all other murders, in staged murders the victims and killers are, on average, older. All victims and offenders in the staged murders are white, with victims being disproportionately white in murders with any kind of unusual body disposition. Likewise, females stand out as victims when the body is posed, staged, or left in other unusual positions. Whereas posed bodies are more likely to include sexual assault, often in serial murders, there is no evidence of either in the staged cases. Lastly, when a body is left in an unusual position, binding is more likely, as well as the use of more "hands on" means of killing the victim, such as stabbing or cutting weapons, bludgeons, ligatures, or hands and feet.

  13. 6-DOF Pose Estimation of a Robotic Navigation Aid by Tracking Visual and Geometric Features.

    Science.gov (United States)

    Ye, Cang; Hong, Soonhac; Tamjidi, Amirhossein

    2015-10-01

    This paper presents a 6-DOF Pose Estimation (PE) method for a Robotic Navigation Aid (RNA) for the visually impaired. The RNA uses a single 3D camera for PE and object detection. The proposed method processes the camera's intensity and range data to estimates the camera's egomotion that is then used by an Extended Kalman Filter (EKF) as the motion model to track a set of visual features for PE. A RANSAC process is employed in the EKF to identify inliers from the visual feature correspondences between two image frames. Only the inliers are used to update the EKF's state. The EKF integrates the egomotion into the camera's pose in the world coordinate system. To retain the EKF's consistency, the distance between the camera and the floor plane (extracted from the range data) is used by the EKF as the observation of the camera's z coordinate. Experimental results demonstrate that the proposed method results in accurate pose estimates for positioning the RNA in indoor environments. Based on the PE method, a wayfinding system is developed for localization of the RNA in a home environment. The system uses the estimated pose and the floorplan to locate the RNA user in the home environment and announces the points of interest and navigational commands to the user through a speech interface. This work was motivated by the limitations of the existing navigation technology for the visually impaired. Most of the existing methods use a point/line measurement sensor for indoor object detection. Therefore, they lack capability in detecting 3D objects and positioning a blind traveler. Stereovision has been used in recent research. However, it cannot provide reliable depth data for object detection. Also, it tends to produce a lower localization accuracy because its depth measurement error quadratically increases with the true distance. This paper suggests a new approach for navigating a blind traveler. The method uses a single 3D time-of-flight camera for both 6-DOF PE and 3D object

  14. Learning the solution sparsity of an ill-posed linear inverse problem with the Variational Garrote

    DEFF Research Database (Denmark)

    Andersen, Michael Riis; Hansen, Sofie Therese; Hansen, Lars Kai

    2013-01-01

    The Variational Garrote is a promising new approach for sparse solutions of ill-posed linear inverse problems (Kappen and Gomez, 2012). We reformulate the prior of the Variational Garrote to follow a simple Binomial law and assign a Beta hyper-prior on the parameter. With the new prior the Variat......The Variational Garrote is a promising new approach for sparse solutions of ill-posed linear inverse problems (Kappen and Gomez, 2012). We reformulate the prior of the Variational Garrote to follow a simple Binomial law and assign a Beta hyper-prior on the parameter. With the new prior...... the Variational Garrote, we show, has a wide range of parameter values for which it at the same time provides low test error and high retrieval of the true feature locations. Furthermore, the new form of the prior and associated hyper-prior leads to a simple update rule in a Bayesian variational inference scheme...

  15. Theory research of seam recognition and welding torch pose control based on machine vision

    Science.gov (United States)

    Long, Qiang; Zhai, Peng; Liu, Miao; He, Kai; Wang, Chunyang

    2017-03-01

    At present, the automation requirement of the welding become higher, so a method of the welding information extraction by vision sensor is proposed in this paper, and the simulation with the MATLAB has been conducted. Besides, in order to improve the quality of robot automatic welding, an information retrieval method for welding torch pose control by visual sensor is attempted. Considering the demands of welding technology and engineering habits, the relative coordinate systems and variables are strictly defined, and established the mathematical model of the welding pose, and verified its feasibility by using the MATLAB simulation in the paper, these works lay a foundation for the development of welding off-line programming system with high precision and quality.

  16. Robot Pose Estimation on Floor Equipped with a Lattice of RFID Tags

    Science.gov (United States)

    Kodaka, Kenri; Niwa, Haruhiko; Sakamoto, Yoshihiro; Sugano, Shigeki

    A method of estimating pose of a robot on a lattice of RFID tags is described. There is a model room in WABOT-HOUSE Laboratory of Waseda University where the floor is equipped with a lattice of RFID tags at 300 mm intervals, simulating a future home environment where robots interact symbiotically with humans. This paper propose a method that uses Monte Carlo localization to estimate the pose of robot on the lattice more precisely than the interval of tags. The experience shows the position and orientation error converge at about 50 mm (straight movement) / 20 mm (rotating movement) and less than 0.1 radian using some properly designed model-parameters, which are tuned in accordance with our simulation results, when two readers are placed appropriately. Moreover, we describe some items about where readers should be placed.

  17. Cartesian Control of a 3-DOF Electro-Pneumatic Actuated Motion Platform with Exteroceptive Pose Measurement

    Directory of Open Access Journals (Sweden)

    Eduardo Izaguirre

    2011-09-01

    Full Text Available This paper presents a kinematic cartesian control scheme of 3 degree of freedom parallel robot driven by electro-pneumatic actuators based on exteroceptive pose measurement system. The inverse kinematics model is used to obtain the desired joint position coordinates from the time-varying trajectory given in task space. The proposal cascade control scheme in task space is based in two loops, the inner loop consisting in a decoupled joint position control and the outer loop which is designed to obtain an appropriate task space trajectory tracking. In order to avoid the on-line computation of direct kinematics an arrangement of inertial sensor and optical encoders are employed to provide the accurate pose measurement of end-effector. The experiment's results demonstrate the great performance of the proposed control scheme in industrial motion tracking application.

  18. Towards a Unified Framework for Pose, Expression, and Occlusion Tolerant Automatic Facial Alignment.

    Science.gov (United States)

    Seshadri, Keshav; Savvides, Marios

    2016-10-01

    We propose a facial alignment algorithm that is able to jointly deal with the presence of facial pose variation, partial occlusion of the face, and varying illumination and expressions. Our approach proceeds from sparse to dense landmarking steps using a set of specific models trained to best account for the shape and texture variation manifested by facial landmarks and facial shapes across pose and various expressions. We also propose the use of a novel l1-regularized least squares approach that we incorporate into our shape model, which is an improvement over the shape model used by several prior Active Shape Model (ASM) based facial landmark localization algorithms. Our approach is compared against several state-of-the-art methods on many challenging test datasets and exhibits a higher fitting accuracy on all of them.

  19. Analysis and solution of the ill-posed inverse heat conduction problem

    Energy Technology Data Exchange (ETDEWEB)

    Weber, C.F.

    1981-01-01

    The inverse conduction problem arises when experimental measurements are taken in the interior of a body, and it is desired to calculate temperature and heat flux values on the surface. The problem is shown to be ill-posed, as the solution exhibits unstable dependence on the given data functions. A special solution procedure is developed for the one-dimensional case which replaces the heat conduction equation with an approximating hyperbolic equation. If viewed from a new perspective, where the roles of the spatial and time variables are interchanged, then an initial value problem for the damped wave equation is obtained. Since this formulation is well-posed, both analytic and numerical solution procedures are readily available. Sample calculations confirm that this approach produces consistent, reliable results for both linear and nonlinear problems.

  20. NUI framework based on real-time head pose estimation and hand gesture recognition

    Directory of Open Access Journals (Sweden)

    Kim Hyunduk

    2016-01-01

    Full Text Available The natural user interface (NUI is used for the natural motion interface without using device or tool such as mice, keyboards, pens and markers. In this paper, we develop natural user interface framework based on two recognition module. First module is real-time head pose estimation module using random forests and second module is hand gesture recognition module, named Hand gesture Key Emulation Toolkit (HandGKET. Using the head pose estimation module, we can know where the user is looking and what the user’s focus of attention is. Moreover, using the hand gesture recognition module, we can also control the computer using the user’s hand gesture without mouse and keyboard. In proposed framework, the user’s head direction and hand gesture are mapped into mouse and keyboard event, respectively.

  1. A new benchmark for pose estimation with ground truth from virtual reality

    DEFF Research Database (Denmark)

    Schlette, Christian; Buch, Anders Glent; Aksoy, Eren Erdal

    2014-01-01

    assembly tasks. Following the eRobotics methodology, a simulatable 3D representation of this platform was modelled in virtual reality. Based on a detailed camera and sensor simulation, we generated a set of benchmark images and point clouds with controlled levels of noise as well as ground truth data......The development of programming paradigms for industrial assembly currently gets fresh impetus from approaches in human demonstration and programming-by-demonstration. Major low- and mid-level prerequisites for machine vision and learning in these intelligent robotic applications are pose estimation...... such as object positions and time stamps. We demonstrate the application of the benchmark to evaluate our latest developments in pose estimation, stereo reconstruction and action recognition and publish the benchmark data for objective comparison of sensor setups and algorithms in industry....

  2. Pose measurement of Anterior Pelvic Plane based on inertial measurement unit in total hip replacement surgeries.

    Science.gov (United States)

    Zhe Cao; Shaojie Su; Hong Chen; Hao Tang; Yixin Zhou; Zhihua Wang

    2016-08-01

    In Total Hip Replacement (THR), inaccurate measurement of Anterior Pelvic Plane (APP), which is usually used as a reference plane, will lead to malposition of the acetabular prosthesis. As a result, the risk of impingement, dislocation and wear will increase and the safe range of motion will be limited. In order to acquire the accurate pose of APP, a measurement system is designed in this paper, which includes two parts: one is used to estimate the initial pose of APP and the other is used to trail dynamic motion of APP. Both parts are composed of an Inertial Measurement Unit (IMU) and magnetometer sensors. An Extended Kalman Filter (EKF) is adopted to fuse the data from IMU and the magnetometer sensors to estimate the orientation of the pelvis. The test results show that the error angle between calculated axis and true axis of the pelvis in geodetic coordinate frame is less than 1.2 degree, which meets the requirement of the surgery.

  3. Rider trunk and bicycle pose estimation with fusion of force/inertial sensors.

    Science.gov (United States)

    Zhang, Yizhai; Chen, Kuo; Yi, Jingang

    2013-09-01

    Estimation of human pose in physical human-machine interactions such as bicycling is challenging because of highly-dimensional human motion and lack of inexpensive, effective motion sensors. In this paper, we present a computational scheme to estimate both the rider trunk pose and the bicycle roll angle using only inertial and force sensors. The estimation scheme is built on a rider-bicycle dynamic model and the fusion of the wearable inertial sensors and the bicycle force sensors. We take advantages of the attractive properties of the robust force measurements and the motion-sensitive inertial measurements. The rider-bicycle dynamic model provides the underlying relationship between the force and the inertial measurements. The extended Kalman filter-based sensor fusion design fully incorporates the dynamic effects of the force measurements. The performance of the estimation scheme is demonstrated through extensive indoor and outdoor riding experiments.

  4. Parallel vision-based pose estimation for non-cooperative spacecraft

    Directory of Open Access Journals (Sweden)

    Ronghua Li

    2015-07-01

    Full Text Available This article proposes a relative pose estimation method between non-cooperative spacecrafts based on parallel binocular vision. As the information of non-cooperative spacecraft in space is not accessible, the target is considered to be freely tumbling in space. The line feature of non-cooperative target is used to extract the feature points first; then the stereo matching and three-dimensional restructuring are taken for the feature points; finally, an algorithm based on parallel binocular vision algorithm is used to calculate the relative pose between the target coordinate and the world coordinate. The experimental results show that the proposed method has high-accuracy real-time performance.

  5. Simulated Lidar Images of Human Pose using a 3DS Max Virtual Laboratory

    Science.gov (United States)

    2015-12-01

    AFRL-RH-WP-TR-2015-0089 SIMULATED LIDAR IMAGES OF HUMAN POSE USING A 3DS MAX VIRTUAL LABORATORY Jeanne Smith Isiah Davenport Infoscitex Corp...MM-YYYY) 11-12-2015 2. REPORT TYPE Interim 3. DATES COVERED (From - To) March 2013 – April 2015 4. TITLE AND SUBTITLE Simulated LIDAR ...Cleared: 88ABW-2016-0242, 25 January 2016 Report contains color 14. ABSTRACT Large sets of 3D Simulated LIDAR (Light Detection and

  6. Monocular Vision- and IMU-Based System for Prosthesis Pose Estimation During Total Hip Replacement Surgery.

    Science.gov (United States)

    Su, Shaojie; Zhou, Yixin; Wang, Zhihua; Chen, Hong

    2017-06-01

    The average age of population increases worldwide, so does the number of total hip replacement surgeries. Total hip replacement, however, often involves a risk of dislocation and prosthetic impingement. To minimize the risk after surgery, we propose an instrumented hip prosthesis that estimates the relative pose between prostheses intraoperatively and ensures the placement of prostheses within a safe zone. We create a model of the hip prosthesis as a ball and socket joint, which has four degrees of freedom (DOFs), including 3-DOF rotation and 1-DOF translation. We mount a camera and an inertial measurement unit (IMU) inside the hollow ball, or "femoral head prosthesis," while printing customized patterns on the internal surface of the socket, or "acetabular cup." Since the sensors were rigidly fixed to the femoral head prosthesis, measuring its motions poses a sensor ego-motion estimation problem. By matching feature points in images of the reference patterns, we propose a monocular vision based method with a relative error of less than 7% in the 3-DOF rotation and 8% in the 1-DOF translation. Further, to reduce system power consumption, we apply the IMU with its data fused by an extended Kalman filter to replace the camera in the 3-DOF rotation estimation, which yields a less than 4.8% relative error and a 21.6% decrease in power consumption. Experimental results show that the best approach to prosthesis pose estimation is a combination of monocular vision-based translation estimation and IMU-based rotation estimation, and we have verified the feasibility and validity of this system in prosthesis pose estimation.

  7. Enhanced Pose Normalization and Matching of Non-Rigid Objects based on Support Vector Machine Modelling

    OpenAIRE

    Papadakis, Panagiotis

    2013-01-01

    International audience; The estimation of 3D surface correspondence constitutes a fundamental problem in shape matching and analysis applications. In the presence of non-rigid shape deformations, the ambiguity of surface correspondence increases together with the complexity of registration algorithms. In this paper, we alleviate this problem by means of 3D pose normalization using One-Class Support Vector Machines (OCSVM). In detail, we show how OCSVM are employed in order to increase the con...

  8. Astronaut Edwin Aldrin poses for photograph beside deployed U.S. flag

    Science.gov (United States)

    1969-01-01

    Astronaut Edwin E. Aldrin Jr., lunar module pilot, poses for a photograph beside the deployed United States flag during Apollo 11 extravehicular activity on the lunar surface. The Lunar Module 'Eagle' is on the left. The footprints of the astronauts are clearly visible in the soil of the moon. This picture was taken by Astronaut Neil A. Armstrong, commander, with a 70mm lunar surface camera.

  9. STS-30 crewmembers pose for onboard portrait on OV-104's middeck

    Science.gov (United States)

    1989-01-01

    During STS-30 aboard Atlantis, Orbiter Vehicle (OV) 104, crewmembers pose for portrait. In front of middeck starboard wall-mounted sleep restraints, are (clockwise from top right) Commander David M. Walker, Mission Specialist (MS) Mary L. Cleave, MS Mark C. Lee, MS Norman E. Thagard, and Pilot Ronald J. Grabe. Crewmembers are wearing red, white, and blue mission polo shirts and light blue flight coveralls.

  10. Pose-free structure from motion using depth from motion constraints.

    Science.gov (United States)

    Zhang, Ji; Boutin, Mireille; Aliaga, Daniel G

    2011-10-01

    Structure from motion (SFM) is the problem of recovering the geometry of a scene from a stream of images taken from unknown viewpoints. One popular approach to estimate the geometry of a scene is to track scene features on several images and reconstruct their position in 3-D. During this process, the unknown camera pose must also be recovered. Unfortunately, recovering the pose can be an ill-conditioned problem which, in turn, can make the SFM problem difficult to solve accurately. We propose an alternative formulation of the SFM problem with fixed internal camera parameters known a priori. In this formulation, obtained by algebraic variable elimination, the external camera pose parameters do not appear. As a result, the problem is better conditioned in addition to involving much fewer variables. Variable elimination is done in three steps. First, we take the standard SFM equations in projective coordinates and eliminate the camera orientations from the equations. We then further eliminate the camera center positions. Finally, we also eliminate all 3-D point positions coordinates, except for their depths with respect to the camera center, thus obtaining a set of simple polynomial equations of degree two and three. We show that, when there are merely a few points and pictures, these "depth-only equations" can be solved in a global fashion using homotopy methods. We also show that, in general, these same equations can be used to formulate a pose-free cost function to refine SFM solutions in a way that is more accurate than by minimizing the total reprojection error, as done when using the bundle adjustment method. The generalization of our approach to the case of varying internal camera parameters is briefly discussed. © 2011 IEEE

  11. Inverse Free Iterative Methods for Nonlinear Ill-Posed Operator Equations

    Directory of Open Access Journals (Sweden)

    Ioannis K. Argyros

    2014-01-01

    ill-posed operator equation F(x=y. The proposed method is a modified form of Tikhonov gradient (TIGRA method considered by Ramlau (2003. The regularization parameter is chosen according to the balancing principle considered by Pereverzev and Schock (2005. The error estimate is derived under a general source condition and is of optimal order. Some numerical examples involving integral equations are also given in this paper.

  12. Dr. David Brown poses with a portrait of Ronald McNair

    Science.gov (United States)

    1999-01-01

    In the gymnasium of Ronald McNair Magnet School in Cocoa, Fla., Dr. David Brown, a NASA astronaut, poses with a portrait of NASA astronaut Ronald McNair. The portrait was presented to the school by Walt Disney World during a tribute to McNair. The school had previously been renamed for the fallen astronaut who was one of a crew of seven who lost their lives during an accident following launch of the Space Shuttle Challenger in January 1986.

  13. Mickey Mouse poses with a portrait of Ronald McNair

    Science.gov (United States)

    1999-01-01

    In the gymnasium of Ronald McNair Magnet School in Cocoa, Fla., Mickey Mouse poses with a portrait of NASA astronaut Ronald McNair. The portrait was presented to the school by Walt Disney World during a tribute to McNair. The school had previously been renamed for the fallen astronaut who was one of a crew of seven who lost their lives during an accident following launch of the Space Shuttle Challenger in January 1986.

  14. Right-Hand Side Dependent Bounds for GMRES Applied to Ill-Posed Problems

    KAUST Repository

    Pestana, Jennifer

    2014-01-01

    © IFIP International Federation for Information Processing 2014. In this paper we apply simple GMRES bounds to the nearly singular systems that arise in ill-posed problems. Our bounds depend on the eigenvalues of the coefficient matrix, the right-hand side vector and the nonnormality of the system. The bounds show that GMRES residuals initially decrease, as residual components associated with large eigenvalues are reduced, after which semi-convergence can be expected because of the effects of small eigenvalues.

  15. Body Parts Dependent Joint Regressors for Human Pose Estimation in Still Images.

    Science.gov (United States)

    Dantone, Matthias; Gall, Juergen; Leistner, Christian; Van Gool, Luc

    2014-11-01

    In this work, we address the problem of estimating 2d human pose from still images. Articulated body pose estimation is challenging due to the large variation in body poses and appearances of the different body parts. Recent methods that rely on the pictorial structure framework have shown to be very successful in solving this task. They model the body part appearances using discriminatively trained, independent part templates and the spatial relations of the body parts using a tree model. Within such a framework, we address the problem of obtaining better part templates which are able to handle a very high variation in appearance. To this end, we introduce parts dependent body joint regressors which are random forests that operate over two layers. While the first layer acts as an independent body part classifier, the second layer takes the estimated class distributions of the first one into account and is thereby able to predict joint locations by modeling the interdependence and co-occurrence of the parts. This helps to overcome typical ambiguities of tree structures, such as self-similarities of legs and arms. In addition, we introduce a novel data set termed FashionPose that contains over 7,000 images with a challenging variation of body part appearances due to a large variation of dressing styles. In the experiments, we demonstrate that the proposed parts dependent joint regressors outperform independent classifiers or regressors. The method also performs better or similar to the state-of-the-art in terms of accuracy, while running with a couple of frames per second.

  16. Convergence rate estimates for Tikhonov's scheme as applied to ill-posed nonconvex optimization problems

    Science.gov (United States)

    Kokurin, M. Yu.

    2017-07-01

    We examine the convergence rate of approximations generated by Tikhonov's scheme as applied to ill-posed constrained optimization problems with general smooth functionals on a convex closed subset of a Hilbert space. Assuming that the solution satisfies a source condition involving the second derivative of the cost functional and depending on the form of constraints, we establish the convergence rate of the Tikhonov approximations in the cases of exact and approximately specified functionals.

  17. Efektifitas Strategi Pembelajaran Kooperatif dan Problem Posing dengan Kombinasi tutorial Online untuk Meningkatkan Pemahaman Materi Mata Kuliah Fisika Dasar

    OpenAIRE

    Kartikawati, Sulistyaning

    2015-01-01

    This research is attempted to identify the effectiveness of cooperative learning and problem posing with on-line tutorials to increase students’ achievement in Basic Physics subject, students’ cooperative skill in posing problems, students’ cooperative skill in inputing problems under computer’s software, students’ thinking process and their attitudes against the implementation of problem posing atrategy with on-line tutorials under cooperative method. This research is carried out at STT Dhar...

  18. The Pose Estimation of Mobile Robot Based on Improved Point Cloud Registration

    Directory of Open Access Journals (Sweden)

    Yanzi Miao

    2016-03-01

    Full Text Available Due to GPS restrictions, an inertial sensor is usually used to estimate the location of indoor mobile robots. However, it is difficult to achieve high-accuracy localization and control by inertial sensors alone. In this paper, a new method is proposed to estimate an indoor mobile robot pose with six degrees of freedom based on an improved 3D-Normal Distributions Transform algorithm (3D-NDT. First, point cloud data are captured by a Kinect sensor and segmented according to the distance to the robot. After the segmentation, the input point cloud data are processed by the Approximate Voxel Grid Filter algorithm in different sized voxel grids. Second, the initial registration and precise registration are performed respectively according to the distance to the sensor. The most distant point cloud data use the 3D-Normal Distributions Transform algorithm (3D-NDT with large-sized voxel grids for initial registration, based on the transformation matrix from the odometry method. The closest point cloud data use the 3D-NDT algorithm with small-sized voxel grids for precise registration. After the registrations above, a final transformation matrix is obtained and coordinated. Based on this transformation matrix, the pose estimation problem of the indoor mobile robot is solved. Test results show that this method can obtain accurate robot pose estimation and has better robustness.

  19. A Neural-Dynamic Architecture for Concurrent Estimation of Object Pose and Identity

    Directory of Open Access Journals (Sweden)

    Oliver Lomp

    2017-04-01

    Full Text Available Handling objects or interacting with a human user about objects on a shared tabletop requires that objects be identified after learning from a small number of views and that object pose be estimated. We present a neurally inspired architecture that learns object instances by storing features extracted from a single view of each object. Input features are color and edge histograms from a localized area that is updated during processing. The system finds the best-matching view for the object in a novel input image while concurrently estimating the object’s pose, aligning the learned view with current input. The system is based on neural dynamics, computationally operating in real time, and can handle dynamic scenes directly off live video input. In a scenario with 30 everyday objects, the system achieves recognition rates of 87.2% from a single training view for each object, while also estimating pose quite precisely. We further demonstrate that the system can track moving objects, and that it can segment the visual array, selecting and recognizing one object while suppressing input from another known object in the immediate vicinity. Evaluation on the COIL-100 dataset, in which objects are depicted from different viewing angles, revealed recognition rates of 91.1% on the first 30 objects, each learned from four training views.

  20. Hardware in the Loop Performance Assessment of LIDAR-Based Spacecraft Pose Determination.

    Science.gov (United States)

    Opromolla, Roberto; Fasano, Giancarmine; Rufino, Giancarlo; Grassi, Michele

    2017-09-24

    In this paper an original, easy to reproduce, semi-analytic calibration approach is developed for hardware-in-the-loop performance assessment of pose determination algorithms processing point cloud data, collected by imaging a non-cooperative target with LIDARs. The laboratory setup includes a scanning LIDAR, a monocular camera, a scaled-replica of a satellite-like target, and a set of calibration tools. The point clouds are processed by uncooperative model-based algorithms to estimate the target relative position and attitude with respect to the LIDAR. Target images, acquired by a monocular camera operated simultaneously with the LIDAR, are processed applying standard solutions to the Perspective-n-Points problem to get high-accuracy pose estimates which can be used as a benchmark to evaluate the accuracy attained by the LIDAR-based techniques. To this aim, a precise knowledge of the extrinsic relative calibration between the camera and the LIDAR is essential, and it is obtained by implementing an original calibration approach which does not need ad-hoc homologous targets (e.g., retro-reflectors) easily recognizable by the two sensors. The pose determination techniques investigated by this work are of interest to space applications involving close-proximity maneuvers between non-cooperative platforms, e.g., on-orbit servicing and active debris removal.

  1. A Neural-Dynamic Architecture for Concurrent Estimation of Object Pose and Identity.

    Science.gov (United States)

    Lomp, Oliver; Faubel, Christian; Schöner, Gregor

    2017-01-01

    Handling objects or interacting with a human user about objects on a shared tabletop requires that objects be identified after learning from a small number of views and that object pose be estimated. We present a neurally inspired architecture that learns object instances by storing features extracted from a single view of each object. Input features are color and edge histograms from a localized area that is updated during processing. The system finds the best-matching view for the object in a novel input image while concurrently estimating the object's pose, aligning the learned view with current input. The system is based on neural dynamics, computationally operating in real time, and can handle dynamic scenes directly off live video input. In a scenario with 30 everyday objects, the system achieves recognition rates of 87.2% from a single training view for each object, while also estimating pose quite precisely. We further demonstrate that the system can track moving objects, and that it can segment the visual array, selecting and recognizing one object while suppressing input from another known object in the immediate vicinity. Evaluation on the COIL-100 dataset, in which objects are depicted from different viewing angles, revealed recognition rates of 91.1% on the first 30 objects, each learned from four training views.

  2. Camera pose estimation for augmented reality in a small indoor dynamic scene

    Science.gov (United States)

    Frikha, Rawia; Ejbali, Ridha; Zaied, Mourad

    2017-09-01

    Camera pose estimation remains a challenging task for augmented reality (AR) applications. Simultaneous localization and mapping (SLAM)-based methods are able to estimate the six degrees of freedom camera motion while constructing a map of an unknown environment. However, these methods do not provide any reference for where to insert virtual objects since they do not have any information about scene structure and may fail in cases of occlusion of three-dimensional (3-D) map points or dynamic objects. This paper presents a real-time monocular piece wise planar SLAM method using the planar scene assumption. Using planar structures in the mapping process allows rendering virtual objects in a meaningful way on the one hand and improving the precision of the camera pose and the quality of 3-D reconstruction of the environment by adding constraints on 3-D points and poses in the optimization process on the other hand. We proposed to benefit from the 3-D planes rigidity motion in the tracking process to enhance the system robustness in the case of dynamic scenes. Experimental results show that using a constrained planar scene improves our system accuracy and robustness compared with the classical SLAM systems.

  3. Hazards posed by distal ash transport and sedimentation from extreme volcanic eruptions

    Science.gov (United States)

    Sahagian, D. L.; Proussevitch, A. A.; White, C. M.; Klewicki, J.

    2016-12-01

    Volcanic ash injected into the upper troposphere and lower stratosphere poses a significant hazard to aviation and human security as a result of extreme, explosive eruptions. These have occurred in the recent geologic past, and are expected to occur again, now that modern society and its infrastructure is far more vulnerable than ever before. Atmospheric transport, dispersion, and sedimentation of Ash particles is controlled by fundamentally different processes than control other particles normally transported in the atmosphere due to their complex internal and external morphology. It is thus necessary to elucidate the fundamental processes of particle-fluid interactions in the upper troposphere and lower stratosphere, where most air traffic resides, and thereby enhance the capability of volcanic ash transport models to predict the ash concentration in distal regions that pose aviation and other hazards. Current Volcanic Ash Transport and Dispersion (VATD) models use simplistic stokes settling velocities for larger ash particles, and treat smaller ash particles (that are a large part of the hazard) merely as passive tracers. By incorporating the dynamics of fine ash particle-atmosphere interactions into existing VATD models provides the foundation for a much more accurate assessment framework applied to the hazard posed by specific future extreme eruptions, and thus dramatically reduce both the risk to air traffic and the cost of airport and flight closures, in addition to human health, water quality, agricultural, infrastructure hazards, as well as ice cap albedo and short term climate impacts.

  4. Non-cooperative spacecraft pose tracking based on point cloud feature

    Science.gov (United States)

    He, Ying; Liang, Bin; He, Jin; Li, Shunzhi

    2017-10-01

    On-orbit services have been paid more and more attention for its role in spacecraft life-extension, capacity improvement and on-orbit debris removal. As most of on-orbit targets are non-cooperative, relatively accurate pose measurement is very essential for subsequent operations. However, with the rapid development of TriDAR, flash LIDAR and other laser scanning equipment in non-cooperative target measurement, it becomes more imperative to research methods for non-cooperative target pose tracking based on 3D point cloud feature. In this paper, a method for non-cooperative target pose tracking based on point cloud feature is proposed. Firstly, the target is identified using curvature, normal, density and other geometric features of the point cloud. Then the particle filter algorithm is used to recognize the position and orientation of the target being tracked by calculating the similarity of the point cloud features of two adjacent frames. Experimental results showed that the proposed method could effectively identify the features of non-cooperative targets and track their position and attitude.

  5. Improving head and body pose estimation through semi-supervised manifold alignment

    KAUST Repository

    Heili, Alexandre

    2014-10-27

    In this paper, we explore the use of a semi-supervised manifold alignment method for domain adaptation in the context of human body and head pose estimation in videos. We build upon an existing state-of-the-art system that leverages on external labelled datasets for the body and head features, and on the unlabelled test data with weak velocity labels to do a coupled estimation of the body and head pose. While this previous approach showed promising results, the learning of the underlying manifold structure of the features in the train and target data and the need to align them were not explored despite the fact that the pose features between two datasets may vary according to the scene, e.g. due to different camera point of view or perspective. In this paper, we propose to use a semi-supervised manifold alignment method to bring the train and target samples closer within the resulting embedded space. To this end, we consider an adaptation set from the target data and rely on (weak) labels, given for example by the velocity direction whenever they are reliable. These labels, along with the training labels are used to bias the manifold distance within each manifold and to establish correspondences for alignment.

  6. Explanation, motivation and question posing routines in university mathematics teachers' pedagogical discourse: a commognitive analysis

    Science.gov (United States)

    Viirman, Olov

    2015-11-01

    This paper investigates the teaching practices used by university mathematics teachers when lecturing, a topic within university mathematics education research which is gaining an increasing interest. In the study, a view of mathematics teaching as a discursive practice is taken, and Sfard's commognitive framework is used to investigate the teaching practices of seven Swedish university mathematics teachers on the topic of functions. The present paper looks at the discourse of mathematics teaching, presenting a categorization of the didactical routines into three categories - explanation, motivation and question posing routines. All of these are present in the discourses of all seven teachers, but within these general categories, a number of different sub-categories of routines are found, used in different ways and to different extent by the various teachers. The explanation routines include known mathematical facts, summary and repetition, different representations, everyday language, and concretization and metaphor; the motivation routines include reference to utility, the nature of mathematics, humour and result focus; and the question posing routines include control questions, asking for facts, enquiries and rhetorical questions. This categorization of question posing routines, for instance, complements those already found in the literature. In addition to providing a valuable insight into the teaching of functions at the university level, the categorizations presented in the study can also be useful for investigating the teaching of other mathematical topics.

  7. Pose Self-Calibration of Stereo Vision Systems for Autonomous Vehicle Applications

    Directory of Open Access Journals (Sweden)

    Basam Musleh

    2016-09-01

    Full Text Available Nowadays, intelligent systems applied to vehicles have grown very rapidly; their goal is not only the improvement of safety, but also making autonomous driving possible. Many of these intelligent systems are based on making use of computer vision in order to know the environment and act accordingly. It is of great importance to be able to estimate the pose of the vision system because the measurement matching between the perception system (pixels and the vehicle environment (meters depends on the relative position between the perception system and the environment. A new method of camera pose estimation for stereo systems is presented in this paper, whose main contribution regarding the state of the art on the subject is the estimation of the pitch angle without being affected by the roll angle. The validation of the self-calibration method is accomplished by comparing it with relevant methods of camera pose estimation, where a synthetic sequence is used in order to measure the continuous error with a ground truth. This validation is enriched by the experimental results of the method in real traffic environments.

  8. Pose Self-Calibration of Stereo Vision Systems for Autonomous Vehicle Applications.

    Science.gov (United States)

    Musleh, Basam; Martín, David; Armingol, José María; de la Escalera, Arturo

    2016-09-14

    Nowadays, intelligent systems applied to vehicles have grown very rapidly; their goal is not only the improvement of safety, but also making autonomous driving possible. Many of these intelligent systems are based on making use of computer vision in order to know the environment and act accordingly. It is of great importance to be able to estimate the pose of the vision system because the measurement matching between the perception system (pixels) and the vehicle environment (meters) depends on the relative position between the perception system and the environment. A new method of camera pose estimation for stereo systems is presented in this paper, whose main contribution regarding the state of the art on the subject is the estimation of the pitch angle without being affected by the roll angle. The validation of the self-calibration method is accomplished by comparing it with relevant methods of camera pose estimation, where a synthetic sequence is used in order to measure the continuous error with a ground truth. This validation is enriched by the experimental results of the method in real traffic environments.

  9. The investigation and implementation of real-time face pose and direction estimation on mobile computing devices

    Science.gov (United States)

    Fu, Deqian; Gao, Lisheng; Jhang, Seong Tae

    2012-04-01

    The mobile computing device has many limitations, such as relative small user interface and slow computing speed. Usually, augmented reality requires face pose estimation can be used as a HCI and entertainment tool. As far as the realtime implementation of head pose estimation on relatively resource limited mobile platforms is concerned, it is required to face different constraints while leaving enough face pose estimation accuracy. The proposed face pose estimation method met this objective. Experimental results running on a testing Android mobile device delivered satisfactory performing results in the real-time and accurately.

  10. Poses, posses e cenários: as fotografias como narrativas da conquista da Europa Poses, possessions and scenarios: the photographs as narratives of the conquest of Europe

    Directory of Open Access Journals (Sweden)

    Gilson Goulart Carrijo

    2012-08-01

    Full Text Available As experiências narrativas etnográficas articulando imagens e textos podem acionar as sensibilidades, os saberes e os sentidos estéticos e culturais presentes na relação ver-o-que-se-diz/dizer-o-que-se-vê. Entre as possibilidades de exploração do universo de imagens estão as fotográficas. A partir das imagens capturadas no cotidiano das travestis, argumento que a pose é um componente sígnico capaz de oferecer vestígios para a compreensão/interpretação de aspectos singulares desse universo que não se esgotam na interpretação usual dos signos letrados. Para o artigo em questão, recorto fragmentos da migração das travestis para a Itália. Um projeto significativamente marcado pela expectativa de trabalho e sobrevivência, mas também que se reveste de glamour num cenário em que as imagens - fotografias enviadas à família e também disponibilizadas na plataforma virtual - compõem narrativas de um sucesso inscrito no corpo, nas joias, nos carros, mas também ancoradas em espaços geográficos diferenciados, capazes de informar sobre "a conquista da Europa".The ethnographic narrative experiences articulating images and texts may trigger the sensitivities, knowledge and esthetical and cultural senses existing in the see-what-is-said/say-what-is-seen relation. The photographs are among the possibilities of exploration of the universe of images. From the images taken from the daily lives of the transvestites, I argue that the posing is a signifying component capable of offering hints for the comprehension/ interpretation of some particular aspects of that universe, not based only on the usual interpretations of the written words. For this article, I gathered fragments of the transvestites' migration to Italy, a project significantly marked by the expectation of working and making a living, but which is also immerse in glamour in a scenario where the images - photographs sent to the families and also made available in the virtual

  11. Multi-view 3D human pose estimation combining single-frame recovery, temporal integration and model adaptation

    NARCIS (Netherlands)

    Hofmann, M.; Gavrila, D.M.

    2009-01-01

    We present a system for the estimation of unconstrained 3D human upper body movement from multiple cameras. Its main novelty lies in the integration of three components: single frame pose recovery, temporal integration and model adaptation. Single frame pose recovery consists of a hypothesis

  12. Absolute stability results for well-posed infinite-dimensional systems with applications to low-gain integral control

    NARCIS (Netherlands)

    Logemann, H; Curtain, RF

    2000-01-01

    We derive absolute stability results for well-posed infinite-dimensional systems which, in a sense, extend the well-known circle criterion to the case that the underlying linear system is the series interconnection of an exponentially stable well-posed infinite-dimensional system and an integrator

  13. Self-Organizing Neural Integration of Pose-Motion Features for Human Action Recognition

    Directory of Open Access Journals (Sweden)

    German Ignacio Parisi

    2015-06-01

    Full Text Available The visual recognition of complex, articulated human movements is fundamental for a wide range of artificial systems oriented towards human-robot communication, action classification, and action-driven perception. These challenging tasks may generally involve the processing of a huge amount of visual information and learning-based mechanisms for generalizing a set of training actions and classifying new samples. To operate in natural environments, a crucial property is the efficient and robust recognition of actions, also under noisy conditions caused by, for instance, systematic sensor errors and temporarily occluded persons. Studies of the mammalian visual system and its outperforming ability to process biological motion information suggest separate neural pathways for the distinct processing of pose and motion features at multiple levels and the subsequent integration of these visual cues for action perception. We present a neurobiologically-motivated approach to achieve noise-tolerant action recognition in real time. Our model consists of self-organizing Growing When Required (GWR networks that obtain progressively generalized representations of sensory inputs and learn inherent spatiotemporal dependencies. During the training, the GWR networks dynamically change their topological structure to better match the input space. We first extract pose and motion features from video sequences and then cluster actions in terms of prototypical pose-motion trajectories. Multi-cue trajectories from matching action frames are subsequently combined to provide action dynamics in the joint feature space. Reported experiments show that our approach outperforms previous results on a dataset of full-body actions captured with a depth sensor, and ranks among the best 21 results for a public benchmark of domestic daily actions.

  14. The Dynamic Features of Lip Corners in Genuine and Posed Smiles

    Directory of Open Access Journals (Sweden)

    Hui Guo

    2018-02-01

    Full Text Available The smile is a frequently expressed facial expression that typically conveys a positive emotional state and friendly intent. However, human beings have also learned how to fake smiles, typically by controlling the mouth to provide a genuine-looking expression. This is often accompanied by inaccuracies that can allow others to determine that the smile is false. Mouth movement is one of the most striking features of the smile, yet our understanding of its dynamic elements is still limited. The present study analyzes the dynamic features of lip corners, and considers how they differ between genuine and posed smiles. Employing computer vision techniques, we investigated elements such as the duration, intensity, speed, symmetry of the lip corners, and certain irregularities in genuine and posed smiles obtained from the UvA-NEMO Smile Database. After utilizing the facial analysis tool OpenFace, we further propose a new approach to segmenting the onset, apex, and offset phases of smiles, as well as a means of measuring irregularities and symmetry in facial expressions. We extracted these features according to 2D and 3D coordinates, and conducted an analysis. The results reveal that genuine smiles have higher values for onset, offset, apex, and total durations, as well as offset displacement, and a variable we termed Irregularity-b (the SD of the apex phase than do posed smiles. Conversely, values tended to be lower for onset and offset Speeds, and Irregularity-a (the rate of peaks, Symmetry-a (the correlation between left and right facial movements, and Symmetry-d (differences in onset frame numbers between the left and right faces. The findings from the present study have been compared to those of previous research, and certain speculations are made.

  15. Minimization of Linear Functionals Defined on| Solutions of Large-Scale Discrete Ill-Posed Problems

    DEFF Research Database (Denmark)

    Elden, Lars; Hansen, Per Christian; Rojas, Marielba

    2003-01-01

    The minimization of linear functionals de ned on the solutions of discrete ill-posed problems arises, e.g., in the computation of con dence intervals for these solutions. In 1990, Elden proposed an algorithm for this minimization problem based on a parametric-programming reformulation involving...... the solution of a sequence of trust-region problems, and using matrix factorizations. In this paper, we describe MLFIP, a large-scale version of this algorithm where a limited-memory trust-region solver is used on the subproblems. We illustrate the use of our algorithm in connection with an inverse heat...

  16. Appearance learning for 3D pose detection of a satellite at close-range

    Science.gov (United States)

    Oumer, Nassir W.; Kriegel, Simon; Ali, Haider; Reinartz, Peter

    2017-03-01

    In this paper we present a learning-based 3D detection of a highly challenging specular object exposed to a direct sunlight at very close-range. An object detection is one of the most important areas of image processing, and can also be used for initialization of local visual tracking methods. While the object detection in 3D space is generally a difficult problem, it poses more difficulties when the object is specular and exposed to the direct sunlight as in a space environment. Our solution to a such problem relies on an appearance learning of a real satellite mock-up based on a vector quantization and the vocabulary tree. Our method, implemented on a standard computer (CPU), exploits a full perspective projection model and provides near real-time 3D pose detection of a satellite for close-range approach and manipulation. The time consuming part of the training (feature description, building the vocabulary tree and indexing, depth buffering and back-projection) are performed offline, while a fast image retrieval and 3D-2D registration are performed on-line. In contrast, the state of the art image-based 3D pose detection methods are slower on CPU or assume a weak perspective camera projection model. In our case the dimension of the satellite is larger than the distance to the camera, hence the assumption of the weak perspective model does not hold. To evaluate the proposed method, the appearance of a full scale mock-up of the rear part of the TerraSAR-X satellite is trained under various illumination and camera views. The training images are captured with a camera mounted on six degrees of freedom robot, which enables to position the camera in a desired view, sampled over a sphere. The views that are not within the workspace of the robot are interpolated using image-based rendering. Moreover, we generate ground truth poses to verify the accuracy of the detection algorithm. The achieved results are robust and accurate even under noise due to specular reflection

  17. Extended 3D Line Segments from RGB-D Data for Pose Estimation

    DEFF Research Database (Denmark)

    Buch, Anders Glent; Jessen, Jeppe Barsøe; Kraft, Dirk

    2013-01-01

    We propose a method for the extraction of complete and rich symbolic line segments in 3D based on RGB-D data. Edges are detected by combining cues from the RGB image and the aligned depth map. 3D line segments are then reconstructed by back-projecting 2D line segments and intersecting this with l...... this with local surface patches computed from the 3D point cloud. Different edge types are classified using the new enriched representation and the potential of this representation for the task of pose estimation is demonstrated....

  18. Newton Type Iteration for Tikhonov Regularization of Nonlinear Ill-Posed Problems in Hilbert Scales

    Directory of Open Access Journals (Sweden)

    Monnanda Erappa Shobha

    2014-01-01

    Full Text Available Recently, Vasin and George (2013 considered an iterative scheme for approximately solving an ill-posed operator equation F(x=y. In order to improve the error estimate available by Vasin and George (2013, in the present paper we extend the iterative method considered by Vasin and George (2013, in the setting of Hilbert scales. The error estimates obtained under a general source condition on x0-x^ (x0 is the initial guess and x^ is the actual solution, using the adaptive scheme proposed by Pereverzev and Schock (2005, are of optimal order. The algorithm is applied to numerical solution of an integral equation in Numerical Example section.

  19. A Monocular SLAM Method to Estimate Relative Pose During Satellite Proximity Operations

    Science.gov (United States)

    2015-03-26

    Memory: 2.0 GB RAM Processor Cores: 4 System type: 64-bit 35 A Point Grey Research Flea 3 camera was used to acquire video sequences ana- lyzed in...Point Grey Research, Inc. Product Name: Flea 3 USB 3.0 Model: FL3-U3-13S2C/M-CS Megapixels: 1.3 Imaging Sensor: Sony IMX035 CMOS, 1/3” Max...threshold is assigned based on the rate of relative motion. Auto- mated initialization based on initial track point motion results in two pose estimates

  20. Dr. David Brown poses with students at Ronald McNair Middle School

    Science.gov (United States)

    1999-01-01

    Dr. David Brown (right), a NASA astronaut, poses with students in the gymnasium of Ronald McNair Magnet School in Cocoa, Fla. From left, the students are Kristin Rexford, Danitra Anderson, Dominique Smith, Fallon Davis, and Qiana Taylor. Brown was at the school to attend a tribute to NASA astronaut Ronald McNair. The school had previously been renamed for the fallen astronaut who was one of a crew of seven, who lost their lives during an accident following launch of the Space Shuttle Challenger in January 1986.

  1. Ms. Rodriquez and Mickey Mouse pose with a portrait of Ronald McNair

    Science.gov (United States)

    1999-01-01

    In the gymnasium of Ronald McNair Magnet School in Cocoa, Fla., Ms. Maria Rodriguez, an Walt Disney World Ambassador, and Mickey Mouse pose with a portrait of NASA astronaut Ronald McNair. The portrait was presented to the school by Walt Disney World during a tribute to McNair. The school had previously been renamed for the fallen astronaut, who was one of a crew of seven who lost their lives during an accident following launch of the Space Shuttle Challenger in January 1986.

  2. Exploiting residual information in the parameter choice for discrete ill-posed problems

    DEFF Research Database (Denmark)

    Hansen, Per Christian; Kilmer, Misha E.; Kjeldsen, Rikke Høj

    2006-01-01

    Most algorithms for choosing the regularization parameter in a discrete ill-posed problem are based on the norm of the residual vector. In this work we propose a different approach, where we seek to use all the information available in the residual vector. We present important relations between...... the residual components and the amount of information that is available in the noisy data, and we show how to use statistical tools and fast Fourier transforms to extract this information efficiently. This approach leads to a computationally inexpensive parameter-choice rule based on the normalized cumulative...... periodogram, which is particularly suited for large-scale problems....

  3. A randomized controlled study of power posing before public speaking exposure for social anxiety disorder: No evidence for augmentative effects.

    Science.gov (United States)

    Davis, Michelle L; Papini, Santiago; Rosenfield, David; Roelofs, Karin; Kolb, Sarah; Powers, Mark B; Smits, Jasper A J

    2017-09-18

    This manuscript details a randomized controlled study designed to test the efficacy of power posing (i.e., briefly holding postures associated with dominance and power) as an augmentative strategy for exposure therapy for social anxiety disorder (SAD). Seventy-three individuals diagnosed with SAD were assigned to one of three conditions: power posing, submissive posing, or rest (no posing) prior to participating in an exposure therapy session. Participants were assessed for between-group differences in pre- and post-manipulation salivary hormone levels, within-session subjective experiences of fear, and pre- and 1-week post-treatment SAD severity outcome measures. Though the intervention resulted in decreased SAD symptom severity one week later, analyses revealed no significant between-group differences on any tested variables. Accordingly, this study provides no evidence to suggest that power posing impacts hormone levels or exposure therapy outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Yoga Poses Increase Subjective Energy and State Self-Esteem in Comparison to ‘Power Poses’

    Directory of Open Access Journals (Sweden)

    Agnieszka Golec de Zavala

    2017-05-01

    Full Text Available Research on beneficial consequences of yoga focuses on the effects of yogic breathing and meditation. Less is known about the psychological effects of performing yoga postures. The present study investigated the effects of yoga poses on subjective sense of energy and self-esteem. The effects of yoga postures were compared to the effects of ‘power poses,’ which arguably increase the sense of power and self-confidence due to their association with interpersonal dominance (Carney et al., 2010. The study tested the novel prediction that yoga poses, which are not associated with interpersonal dominance but increase bodily energy, would increase the subjective feeling of energy and therefore increase self-esteem compared to ‘high power’ and ‘low power’ poses. A two factorial, between participants design was employed. Participants performed either two standing yoga poses with open front of the body (n = 19, two standing yoga poses with covered front of the body (n = 22, two expansive, high power poses (n = 21, or two constrictive, low power poses (n = 20 for 1-min each. The results showed that yoga poses in comparison to ‘power poses’ increased self-esteem. This effect was mediated by an increased subjective sense of energy and was observed when baseline trait self-esteem was controlled for. These results suggest that the effects of performing open, expansive body postures may be driven by processes other than the poses’ association with interpersonal power and dominance. This study demonstrates that positive effects of yoga practice can occur after performing yoga poses for only 2 min.

  5. Deformation-specific and deformation-invariant visual object recognition: pose vs. identity recognition of people and deforming objects.

    Science.gov (United States)

    Webb, Tristan J; Rolls, Edmund T

    2014-01-01

    When we see a human sitting down, standing up, or walking, we can recognize one of these poses independently of the individual, or we can recognize the individual person, independently of the pose. The same issues arise for deforming objects. For example, if we see a flag deformed by the wind, either blowing out or hanging languidly, we can usually recognize the flag, independently of its deformation; or we can recognize the deformation independently of the identity of the flag. We hypothesize that these types of recognition can be implemented by the primate visual system using temporo-spatial continuity as objects transform as a learning principle. In particular, we hypothesize that pose or deformation can be learned under conditions in which large numbers of different people are successively seen in the same pose, or objects in the same deformation. We also hypothesize that person-specific representations that are independent of pose, and object-specific representations that are independent of deformation and view, could be built, when individual people or objects are observed successively transforming from one pose or deformation and view to another. These hypotheses were tested in a simulation of the ventral visual system, VisNet, that uses temporal continuity, implemented in a synaptic learning rule with a short-term memory trace of previous neuronal activity, to learn invariant representations. It was found that depending on the statistics of the visual input, either pose-specific or deformation-specific representations could be built that were invariant with respect to individual and view; or that identity-specific representations could be built that were invariant with respect to pose or deformation and view. We propose that this is how pose-specific and pose-invariant, and deformation-specific and deformation-invariant, perceptual representations are built in the brain.

  6. Deformation-specific and deformation-invariant visual object recognition: pose vs identity recognition of people and deforming objects

    Directory of Open Access Journals (Sweden)

    Tristan J Webb

    2014-04-01

    Full Text Available When we see a human sitting down, standing up, or walking, we can recognise one of these poses independently of the individual, or we can recognise the individual person, independently of the pose. The same issues arise for deforming objects. For example, if we see a flag deformed by the wind, either blowing out or hanging languidly, we can usually recognise the flag, independently of its deformation; or we can recognise the deformation independently of the identity of the flag. We hypothesize that these types of recognition can be implemented by the primate visual system using temporo-spatial continuity as objects transform as a learning principle. In particular, we hypothesize that pose or deformation can be learned under conditions in which large numbers of different people are successively seen in the same pose, or objects in the same deformation. We also hypothesize that person-specific representations that are independent of pose, and object-specific representations that are independent of deformation and view, could be built, when individual people or objects are observed successively transforming from one pose or deformation and view to another. These hypotheses were tested in a simulation of the ventral visual system, VisNet, that uses temporal continuity, implemented in a synaptic learning rule with a short-term memory trace of previous neuronal activity, to learn invariant representations. It was found that depending on the statistics of the visual input, either pose-specific or deformation-specific representations could be built that were invariant with respect to individual and view; or that identity-specific representations could be built that were invariant with respect to pose or deformation and view. We propose that this is how pose-specific and pose-invariant, and deformation-specific and deformation-invariant, perceptual representations are built in the brain.

  7. Yoga Poses Increase Subjective Energy and State Self-Esteem in Comparison to ‘Power Poses’

    Science.gov (United States)

    Golec de Zavala, Agnieszka; Lantos, Dorottya; Bowden, Deborah

    2017-01-01

    Research on beneficial consequences of yoga focuses on the effects of yogic breathing and meditation. Less is known about the psychological effects of performing yoga postures. The present study investigated the effects of yoga poses on subjective sense of energy and self-esteem. The effects of yoga postures were compared to the effects of ‘power poses,’ which arguably increase the sense of power and self-confidence due to their association with interpersonal dominance (Carney et al., 2010). The study tested the novel prediction that yoga poses, which are not associated with interpersonal dominance but increase bodily energy, would increase the subjective feeling of energy and therefore increase self-esteem compared to ‘high power’ and ‘low power’ poses. A two factorial, between participants design was employed. Participants performed either two standing yoga poses with open front of the body (n = 19), two standing yoga poses with covered front of the body (n = 22), two expansive, high power poses (n = 21), or two constrictive, low power poses (n = 20) for 1-min each. The results showed that yoga poses in comparison to ‘power poses’ increased self-esteem. This effect was mediated by an increased subjective sense of energy and was observed when baseline trait self-esteem was controlled for. These results suggest that the effects of performing open, expansive body postures may be driven by processes other than the poses’ association with interpersonal power and dominance. This study demonstrates that positive effects of yoga practice can occur after performing yoga poses for only 2 min. PMID:28553249

  8. Three-dimensional pose estimation model for object with complex surface

    Directory of Open Access Journals (Sweden)

    Ronghua Li

    2015-02-01

    Full Text Available The proposed three-dimensional pose estimation model for object with complex surface, which primarily absorbs the essence of scale-invariant feature transform and iterative closest point algorithm, includes two steps, off-line and online. At first, two kinds of feature databases are established in the off-line operations. Then, the online process mainly has three steps. The first one is two-dimensional edge extraction from red–green–blue (RGB information based on scale-invariant feature transform algorithm. The second one is three-dimensional surface reconstruction from the previous two-dimensional edge and the depth information obtained from depth camera. The last one is three-dimensional pose estimation based on camera calibration and iterative closest point algorithm. The Kinect camera is selected as the information acquisition device which can produce red–green–blue information and depth information. In the experiment, the container twist-lock with complex surface is taken as the object. The result shows that the accuracy of the proposed model is very high.

  9. Emotional Interaction with a Robot Using Facial Expressions, Face Pose and Hand Gestures

    Directory of Open Access Journals (Sweden)

    Myung-Ho Ju

    2012-09-01

    Full Text Available Facial expression is one of the major cues for emotional communications between humans and robots. In this paper, we present emotional human robot interaction techniques using facial expressions combined with an exploration of other useful concepts, such as face pose and hand gesture. For the efficient recognition of facial expressions, it is important to understand the positions of facial feature points. To do this, our technique estimates the 3D positions of each feature point by constructing 3D face models fitted on the user. To construct the 3D face models, we first construct an Active Appearance Model (AAM for variations of the facial expression. Next, we estimate depth information at each feature point from frontal- and side-view images. By combining the estimated depth information with AAM, the 3D face model is fitted on the user according to the various 3D transformations of each feature point. Self-occlusions due to the 3D pose variation are also processed by the region weighting function on the normalized face at each frame. The recognized facial expressions - such as happiness, sadness, fear and anger - are used to change the colours of foreground and background objects in the robot displays, as well as other robot responses. The proposed method displays desirable results in viewing comics with the entertainment robots in our experiments.

  10. A problem-posing approach to teaching the topic of radioactivity

    Science.gov (United States)

    Klaassen, C. W. J. M.

    1995-12-01

    This thesis highlights a problem-posing approach to science education. By this is meant an approach that explicitly aims at providing students with content-related motives for extending their existing conceptual resources, experiential base and belief system in a certain direction, such that a further development in that direction eventually leads to a proper understanding of science. An elaboration of that approach consists in designing, testing, improving, etc, concrete didactical structures. The eventual aim of the approach is a coherent, and by means of developmental research empirically supported, didactical structure that covers the whole of science education. The thesis also contains a few steps in the direction suggested by this programmatic view. It contains an illustration of the heuristic value of an articulation of a didactical structure in some main substructures, based on the work of van Hiele and ten Voorde. It further contains a discussion of some methodological aspects relating to the design and evaluation of a didactical structure, and of the role that a further developed version of Davidson's theory of interpretation could play in this respect. A detailed didactical structure of the topic of radioactivity is presented, evaluated and, on the basis of the evaluation, judged as `good enough.' Also the role of the teacher in a problem-posing approach is dis-cussed, and in particular the consequences for that role of giving students control over and responsibility for the progress of their learning process with respect to content.

  11. Stereo-Vision-Based Relative Pose Estimation for the Rendezvous and Docking of Noncooperative Satellites

    Directory of Open Access Journals (Sweden)

    Feng Yu

    2014-01-01

    Full Text Available Autonomous on-orbit servicing is expected to play an important role in future space activities. Acquiring the relative pose information and inertial parameters of target is one of the key technologies for autonomous capturing. In this paper, an estimation method of relative pose based on stereo vision is presented for the final phase of the rendezvous and docking of noncooperative satellites. The proposed estimation method utilizes the sparse stereo vision algorithm instead of the dense stereo algorithm. The method consists of three parts: (1 body frame reestablishment, which establishes the body-fixed frame for the target satellite using the natural features on the surface and measures the relative attitude based on TRIAD and QUEST; (2 translational parameter estimation, which designs a standard Kalman filter to estimate the translational states and the location of mass center; (3 rotational parameter estimation, which designs an extended Kalman filter and an unscented Kalman filter, respectively, to estimate the rotational states and all the moment-of-inertia ratios. Compared to the dense stereo algorithm, the proposed method can avoid degeneracy when the target has a high degree of axial symmetry and reduce the number of sensors. The validity of the proposed method is verified by numerical simulations.

  12. Squeezeposenet: Image Based Pose Regression with Small Convolutional Neural Networks for Real Time Uas Navigation

    Science.gov (United States)

    Müller, M. S.; Urban, S.; Jutzi, B.

    2017-08-01

    The number of unmanned aerial vehicles (UAVs) is increasing since low-cost airborne systems are available for a wide range of users. The outdoor navigation of such vehicles is mostly based on global navigation satellite system (GNSS) methods to gain the vehicles trajectory. The drawback of satellite-based navigation are failures caused by occlusions and multi-path interferences. Beside this, local image-based solutions like Simultaneous Localization and Mapping (SLAM) and Visual Odometry (VO) can e.g. be used to support the GNSS solution by closing trajectory gaps but are computationally expensive. However, if the trajectory estimation is interrupted or not available a re-localization is mandatory. In this paper we will provide a novel method for a GNSS-free and fast image-based pose regression in a known area by utilizing a small convolutional neural network (CNN). With on-board processing in mind, we employ a lightweight CNN called SqueezeNet and use transfer learning to adapt the network to pose regression. Our experiments show promising results for GNSS-free and fast localization.

  13. A pose-based structural dynamic model updating method for serial modular robots

    Science.gov (United States)

    Mohamed, Richard Phillip; Xi, Fengfeng (Jeff); Chen, Tianyan

    2017-02-01

    A new approach is presented for updating the structural dynamic component models of serial modular robots using experimental data from component tests such that the updated model of the entire robot assembly can provide accurate results in any pose. To accomplish this, a test-analysis component mode synthesis (CMS) model with fixed-free component boundaries is implemented to directly compare measured frequency response functions (FRFs) from vibration experiments of individual modules. The experimental boundary conditions are made to emulate module connection interfaces and can enable individual joint and link modules to be tested in arbitrary poses. By doing so, changes in the joint dynamics can be observed and more FRF data points can be obtained from experiments to be used in the updating process. Because this process yields an overdetermined system of equations, a direct search method with nonlinear constraints on the resonances and antiresonances is used to update the FRFs of the analytical component models. The effectiveness of the method is demonstrated with experimental case studies on an adjustable modular linkage system. Overall, the method can enable virtual testing of modular robot systems without the need to perform further testing on entire assemblies.

  14. Bias Estimations for Ill-posed Problem of Celestial Positioning Using the Sun and Precision Analysis

    Directory of Open Access Journals (Sweden)

    ZHAN Yinhu

    2016-08-01

    Full Text Available Lunar/Mars rovers own sun sensors for navigation, however, long-time tracking for the sun impacts on the real-time activity of navigation. Absolute positioning method by observing the sun with a super short tracking period such as 1 or 2 minutes is researched in this paper. Linear least squares model of altitude positioning method is deduced, and the ill-posed problem of celestial positioning using the sun is brought out for the first time. Singular value decomposition method is used to diagnose the ill-posed problem, and different bias estimations are employed and compared by simulative calculations. Results of the calculations indicate the superiority of bias estimations which can effectively improve initial values. However, bias estimations are greatly impacted by initial values, because the initial values converge at a line which passes by the real value and is vertical relative to the orientation of the sun. The research of this paper is of some value to application.

  15. First evaluation of the threat posed by antifouling biocides in the Southern Adriatic Sea.

    Science.gov (United States)

    Manzo, Sonia; Ansanelli, Giuliana; Parrella, Luisa; Di Landa, Giuseppe; Massanisso, Paolo; Schiavo, Simona; Minopoli, Carmine; Lanza, Bruno; Boggia, Raffaella; Aleksi, Pellumb; Tabaku, Afrim

    2014-08-01

    The CARISMA project (characterization and ecological risk analysis of antifouling biocides in the Southern Adriatic Sea) aims to appraise the quality of the Southern Adriatic Sea between Italy (Apulia region) and Albania and, in particular, the impact due to the use of biocidal antifouling coatings. Under this project, a preliminary survey at the main hot spots of contamination (e.g. ports and marinas) was conducted at the end of the nautical season in 2012. Chemical seawater analyses were complemented with ecotoxicological assays and the results were analyzed by principal component analysis (PCA). As expected, PCA splits the Albanian and Italian ports, according to the different degrees of contamination indicated for the two countries by the experimental data, highlighting the most critical situation in one port of Apulia. In addition, in order to assess the potential adverse ecological effects posed by antifouling agents (i.e. tributyltin (TBT)-irgarol-diuron) on non-target marine organisms, hazard quotients (HQ) were calculated. The results showed a low risk posed by irgarol and diuron whereas the probability of adverse effects was high in the case of TBT.

  16. A Layered Approach for Robust Spatial Virtual Human Pose Reconstruction Using a Still Image

    Directory of Open Access Journals (Sweden)

    Chengyu Guo

    2016-02-01

    Full Text Available Pedestrian detection and human pose estimation are instructive for reconstructing a three-dimensional scenario and for robot navigation, particularly when large amounts of vision data are captured using various data-recording techniques. Using an unrestricted capture scheme, which produces occlusions or breezing, the information describing each part of a human body and the relationship between each part or even different pedestrians must be present in a still image. Using this framework, a multi-layered, spatial, virtual, human pose reconstruction framework is presented in this study to recover any deficient information in planar images. In this framework, a hierarchical parts-based deep model is used to detect body parts by using the available restricted information in a still image and is then combined with spatial Markov random fields to re-estimate the accurate joint positions in the deep network. Then, the planar estimation results are mapped onto a virtual three-dimensional space using multiple constraints to recover any deficient spatial information. The proposed approach can be viewed as a general pre-processing method to guide the generation of continuous, three-dimensional motion data. The experiment results of this study are used to describe the effectiveness and usability of the proposed approach.

  17. 3D head pose estimation and tracking using particle filtering and ICP algorithm

    KAUST Repository

    Ben Ghorbel, Mahdi

    2010-01-01

    This paper addresses the issue of 3D head pose estimation and tracking. Existing approaches generally need huge database, training procedure, manual initialization or use face feature extraction manually extracted. We propose a framework for estimating the 3D head pose in its fine level and tracking it continuously across multiple Degrees of Freedom (DOF) based on ICP and particle filtering. We propose to approach the problem, using 3D computational techniques, by aligning a face model to the 3D dense estimation computed by a stereo vision method, and propose a particle filter algorithm to refine and track the posteriori estimate of the position of the face. This work comes with two contributions: the first concerns the alignment part where we propose an extended ICP algorithm using an anisotropic scale transformation. The second contribution concerns the tracking part. We propose the use of the particle filtering algorithm and propose to constrain the search space using ICP algorithm in the propagation step. The results show that the system is able to fit and track the head properly, and keeps accurate the results on new individuals without a manual adaptation or training. © Springer-Verlag Berlin Heidelberg 2010.

  18. PENGARUH DARI PROBLEM POSING METHOD TERHADAP KREATIVITAS VERBAL SISWA SMP KELAS VII

    Directory of Open Access Journals (Sweden)

    Bagus Priambodo

    2013-10-01

    Full Text Available Verbal creativity is the ability to think fluent, flexible, and original that manifested through the words. Psychological freedom is one factor that can develop creativity. One alternative teaching methods that provide freedom in an atmosphere of learning is the Problem Posing Method (PPM which is triggered by Paulo Freire. This research aims to determine the presence or absence of the influence of PPM on verbal creativity. Characteristic of the subjects was junior high school students in grade 7th, received conventional learning materials, and have never had learning by using PPM. This study used a non-randomized pretest-posttest control group design. Subjects in the study were divided into two, experimental group (N = 33 and control group (N= 35. The data was collected using the Verbal Creativity Test. The results of hypothesis testing used Independent Sample T Test techniques showed the differences of mean = 3.294, α = 0.014 with (p<0.05. Keywords: Verbal creativity, problem posing method, a test of verbal creativity, junior high school students

  19. Handheld pose tracking using vision-inertial sensors with occlusion handling

    Science.gov (United States)

    Li, Juan; Slembrouck, Maarten; Deboeverie, Francis; Bernardos, Ana M.; Besada, Juan A.; Veelaert, Peter; Aghajan, Hamid; Casar, José R.; Philips, Wilfried

    2016-07-01

    Tracking of a handheld device's three-dimensional (3-D) position and orientation is fundamental to various application domains, including augmented reality (AR), virtual reality, and interaction in smart spaces. Existing systems still offer limited performance in terms of accuracy, robustness, computational cost, and ease of deployment. We present a low-cost, accurate, and robust system for handheld pose tracking using fused vision and inertial data. The integration of measurements from embedded accelerometers reduces the number of unknown parameters in the six-degree-of-freedom pose calculation. The proposed system requires two light-emitting diode (LED) markers to be attached to the device, which are tracked by external cameras through a robust algorithm against illumination changes. Three data fusion methods have been proposed, including the triangulation-based stereo-vision system, constraint-based stereo-vision system with occlusion handling, and triangulation-based multivision system. Real-time demonstrations of the proposed system applied to AR and 3-D gaming are also included. The accuracy assessment of the proposed system is carried out by comparing with the data generated by the state-of-the-art commercial motion tracking system OptiTrack. Experimental results show that the proposed system has achieved high accuracy of few centimeters in position estimation and few degrees in orientation estimation.

  20. Correlation techniques as applied to pose estimation in space station docking

    Science.gov (United States)

    Rollins, John M.; Juday, Richard D.; Monroe, Stanley E., Jr.

    2002-08-01

    The telerobotic assembly of space-station components has become the method of choice for the International Space Station (ISS) because it offers a safe alternative to the more hazardous option of space walks. The disadvantage of telerobotic assembly is that it does not necessarily provide for direct arbitrary views of mating interfaces for the teleoperator. Unless cameras are present very close to the interface positions, such views must be generated graphically, based on calculated pose relationships derived from images. To assist in this photogrammetric pose estimation, circular targets, or spots, of high contrast have been affixed on each connecting module at carefully surveyed positions. The appearance of a subset of spots must form a constellation of specific relative positions in the incoming image stream in order for the docking to proceed. Spot positions are expressed in terms of their apparent centroids in an image. The precision of centroid estimation is required to be as fine as 1/20th pixel, in some cases. This paper presents an approach to spot centroid estimation using cross correlation between spot images and synthetic spot models of precise centration. Techniques for obtaining sub-pixel accuracy and for shadow and lighting irregularity compensation are discussed.

  1. A cross docking pipeline for improving pose prediction and virtual screening performance

    Science.gov (United States)

    Kumar, Ashutosh; Zhang, Kam Y. J.

    2017-08-01

    Pose prediction and virtual screening performance of a molecular docking method depend on the choice of protein structures used for docking. Multiple structures for a target protein are often used to take into account the receptor flexibility and problems associated with a single receptor structure. However, the use of multiple receptor structures is computationally expensive when docking a large library of small molecules. Here, we propose a new cross-docking pipeline suitable to dock a large library of molecules while taking advantage of multiple target protein structures. Our method involves the selection of a suitable receptor for each ligand in a screening library utilizing ligand 3D shape similarity with crystallographic ligands. We have prospectively evaluated our method in D3R Grand Challenge 2 and demonstrated that our cross-docking pipeline can achieve similar or better performance than using either single or multiple-receptor structures. Moreover, our method displayed not only decent pose prediction performance but also better virtual screening performance over several other methods.

  2. Robust and Accurate Multiple-Camera Pose Estimation toward Robotic Applications

    Directory of Open Access Journals (Sweden)

    Yong Liu

    2014-09-01

    Full Text Available Pose estimation methods in robotics applications frequently suffer from inaccuracy due to a lack of correspondence and real-time constraints, and instability from a wide range of viewpoints, etc. In this paper, we present a novel approach for estimating the poses of all the cameras in a multi-camera system in which each camera is placed rigidly using only a few coplanar points simultaneously. Instead of solving the orientation and translation for the multi-camera system from the overlapping point correspondences among all the cameras directly, we employ homography, which can map image points with 3D coplanar-referenced points. In our method, we first establish the corresponding relations between each camera by their Euclidean geometries and optimize the homographies of the cameras; then, we solve the orientation and translation for the optimal homographies. The results from simulations and real case experiments show that our approach is accurate and robust for implementation in robotics applications. Finally, a practical implementation in a ping-pong robot is described in order to confirm the validity of our approach.

  3. High-precision pose measurement method in wind tunnels based on laser-aided vision technology

    Directory of Open Access Journals (Sweden)

    Liu Wei

    2015-08-01

    Full Text Available The measurement of position and attitude parameters for the isolated target from a high-speed aircraft is a great challenge in the field of wind tunnel simulation technology. In this paper, firstly, an image acquisition method for small high-speed targets with multi-dimensional movement in wind tunnel environment is proposed based on laser-aided vision technology. Combining with the trajectory simulation of the isolated model, the reasonably distributed laser stripes and self-luminous markers are utilized to capture clear images of the object. Then, after image processing, feature extraction, stereo correspondence and reconstruction, three-dimensional information of laser stripes and self-luminous markers are calculated. Besides, a pose solution method based on projected laser stripes and self-luminous markers is proposed. Finally, simulation experiments on measuring the position and attitude of high-speed rolling targets are conducted, as well as accuracy verification experiments. Experimental results indicate that the proposed method is feasible and efficient for measuring the pose parameters of rolling targets in wind tunnels.

  4. Estimating the ventilation-perfusion distribution: an ill-posed integral equation problem.

    Science.gov (United States)

    Lim, L L; Whitehead, J

    1992-03-01

    The distribution of ventilation-perfusion ratio over the lung is a useful indicator of the efficiency of lung function. Information about this distribution can be obtained by observing the retention in blood of inert gases passed through the lung. These retentions are related to the ventilation-perfusion distribution through an ill-posed integral equation. An unusual feature of this problem of estimating the ventilation-perfusion distribution is the small amount of data available; typically there are just six data points, as only six gases are used in the experiment. A nonparametric smoothing method is compared to a simpler method that models the distribution as a histogram with five classes. Results from the smoothing method are found to be very unstable. In contrast, the simpler method gives stable solutions with parameters that are physiologically meaningful. It is concluded that while such smoothing methods may be useful for solving some ill-posed integral equation problems, the simpler method is preferable when data are scarce.

  5. The Relationship between Students' Problem Posing and Problem Solving Abilities and Beliefs: A Small-Scale Study with Chinese Elementary School Children

    Science.gov (United States)

    Limin, Chen; Van Dooren, Wim; Verschaffel, Lieven

    2013-01-01

    The goal of the present study is to investigate the relationship between pupils' problem posing and problem solving abilities, their beliefs about problem posing and problem solving, and their general mathematics abilities, in a Chinese context. Five instruments, i.e., a problem posing test, a problem solving test, a problem posing questionnaire,…

  6. Investigation of learning environment for arithmetic word problems by problem posing as sentence integration in Indonesian language

    Science.gov (United States)

    Hasanah, N.; Hayashi, Y.; Hirashima, T.

    2017-02-01

    Arithmetic word problems remain one of the most difficult area of teaching mathematics. Learning by problem posing has been suggested as an effective way to improve students’ understanding. However, the practice in usual classroom is difficult due to extra time needed for assessment and giving feedback to students’ posed problems. To address this issue, we have developed a tablet PC software named Monsakun for learning by posing arithmetic word problems based on Triplet Structure Model. It uses the mechanism of sentence-integration, an efficient implementation of problem-posing that enables agent-assessment of posed problems. The learning environment has been used in actual Japanese elementary school classrooms and the effectiveness has been confirmed in previous researches. In this study, ten Indonesian elementary school students living in Japan participated in a learning session of problem posing using Monsakun in Indonesian language. We analyzed their learning activities and show that students were able to interact with the structure of simple word problem using this learning environment. The results of data analysis and questionnaire suggested that the use of Monsakun provides a way of creating an interactive and fun environment for learning by problem posing for Indonesian elementary school students.

  7. Winners, losers, and posers: The effect of power poses on testosterone and risk-taking following competition.

    Science.gov (United States)

    Smith, Kristopher M; Apicella, Coren L

    2017-06-01

    A contribution to a special issue on Hormones and Human Competition. The effect of postural power displays (i.e. power poses) on hormone levels and decision-making has recently been challenged. While Carney et al. (2010) found that holding brief postural displays of power leads to increased testosterone, decreased cortisol and greater economic risk taking, this failed to replicate in a recent high-powered study (Ranehill et al. 2015). It has been put forward that subtle differences in social context may account for the differences in results. Power displays naturally occur within the context of competitions, as do changes in hormones, and researchers have yet to examine the effects of poses within this ecologically relevant context. Using a large sample of 247 male participants, natural winners and losers of a physical competition were randomly assigned to hold a low, neutral or high-power postural display. We found no main effect of pose type on testosterone, cortisol, risk or feelings of power. Winners assigned to a high-power pose had a relative, albeit small, rise in testosterone compared to winners who held neutral or low-power poses. For losers, we found little evidence that high-power poses lead to increased testosterone relative to those holding neutral or low-powered poses. If anything, the reverse was observed - losers had a reduction in testosterone after holding high-power poses. To the extent that changes in testosterone modulate social behaviors adaptively, it is possible that the relative reduction in testosterone observed in losers taking high-powered poses is designed to inhibit further "winner-like" behavior that could result in continued defeat and harm. Still, effects were small, multiple comparisons were made, and the results ran counter to our predictions. We thus treat these conclusions as preliminary. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. A fast bottom-up approach toward three-dimensional human pose estimation using an array of cameras

    Science.gov (United States)

    Ghaneizad, Maryam; Kavehvash, Zahra; Mehrany, Khashayar; Hosseini, S. M. Ali Tayaranian

    2017-08-01

    In this paper, employing recorded images of multiple cameras, we propose a novel fast approach for three-dimensional (3D) human pose reconstruction. Opening a new framework to the pose estimation application, the proposed method is inspired by optical 3D reconstruction algorithms conventionally used for integral imaging. Thanks to the fact that the pose estimation can be carried out by using only key features of the raw recorded images, the computation time and the complexity of our method are considerably reduced. Furthermore, utilizing the here proposed algorithm, rapid variations in actions can be easily tracked. The validity of the proposed method is demonstrated by several experimental results in different postures.

  9. Task-Specific Scoring Functions for Predicting Ligand Binding Poses and Affinity and for Screening Enrichment.

    Science.gov (United States)

    Ashtawy, Hossam; Mahapatra, Nihar Ranjan

    2017-11-30

    Molecular docking, scoring, and virtual screening play an increasingly important role in computer-aided drug discovery. Scoring functions (SFs) are typically employed to predict the binding conformation (docking task), binding affinity (scoring task), and binary activity level (screening task) of ligands against a critical protein target in a disease's pathway. In most molecular docking software packages available today, a generic binding affinity-based (BA-based) SF is invoked for all three tasks to solve three different, but related, prediction problems. The limited predictive accuracies of such SFs in these three tasks has been a major roadblock toward cost-effective drug discovery. Therefore, in this work, we develop BT-Score, an ensemble machine-learning (ML) SF of boosted decision trees and thousands of predictive descriptors to estimate BA. BT-Score reproduced BA of out-of-sample test complexes with correlation of 0.825. Even with this high accuracy in the scoring task, we demonstrate that the docking and screening performance of BT-Score and other BA-based SFs is far from ideal. This has motivated us to build two task-specific ML SFs for the docking and screening problems. We propose BT-Dock, a boosted-tree ensemble model trained on a large number of native and computer-generated ligand conformations and optimized to predict binding poses explicitly. The model has shown an average improvement of 25% over its BA-based counterparts in different ligand pose prediction scenarios. Similar improvement has also been obtained by our screening-based SF, BT-Screen, which directly models the ligand activity labels as a classification problem. BT-Screen is trained on thousands of active and inactive protein-ligand complexes to optimize it for finding real actives from databases of ligands not seen in its training set. In addition to the three task-specific SFs, we propose a novel multi-task deep neural network (MT-Net) that is trained on data from the three tasks to

  10. Antibiotics as CECs: An Overview of the Hazards Posed by Antibiotics and Antibiotic Resistance

    Directory of Open Access Journals (Sweden)

    Geoffrey Ivan Scott

    2016-04-01

    Full Text Available ABSTRACTMonitoring programs have traditionally monitored legacy contaminants but are shifting focus to Contaminants of Emerging Concern (CECs. CECs present many challenges for monitoring and assessment, because measurement methods don't always exist nor have toxicological studies been fully conducted to place results in proper context. Also some CECs affect metabolic pathways to produce adverse outcomes that are not assessed through traditional toxicological evaluations. Antibiotics are CECs that pose significant environmental risks including development of both toxic effects at high doses and antibiotic resistance at doses well below the Minimum Inhibitory Concentration (MIC which kill bacteria and have been found in nearly half of all sites monitored in the US. Antimicrobial resistance has generally been attributed to the use of antibiotics in medicine for humans and livestock as well as aquaculture operations. The objective of this study was to assess the extent and magnitude of antibiotics in the environment and estimate their potential hazards in the environment. Antibiotics concentrations were measured in a number of monitoring studies which included Waste Water Treatment Plants (WWTP effluent, surface waters, sediments and biota. A number of studies reported levels of Antibiotic Resistant Microbes (ARM in surface waters and some studies found specific ARM genes (e.g. the blaM-1 gene in E. coli which may pose additional environmental risk. High levels of this gene were found to survive WWTP disinfection and accumulated in sediment at levels 100-1000 times higher than in the sewerage effluent, posing potential risks for gene transfer to other bacteria.in aquatic and marine ecosystems. Antibiotic risk assessment approaches were developed based on the use of MICs and MIC Ratios [High (Antibiotic Resistant/Low (Antibiotic Sensitive MIC] for each antibiotic indicating the range of bacterial adaptability to each antibiotic to help define the No

  11. Review of the Risks Posed to Drinking Water by Man-Made Nanoparticels

    DEFF Research Database (Denmark)

    Tiede, K.; Westerhoff, P.; Hansen, Steffen Foss

    There is increasing concern over the health effects of engineered nanoparticles (ENPs). Humans can be exposed to these particles directly during product use or indirectly following release to the natural environment. One potential indirect exposure route is through the consumption of contaminated...... drinking waters. In order to address these concerns, the U.K. Drinking Water Inspectorate (DWI) has published a "Review of the risks posed to drinking water by man-made nanoparticles"(DWI 70/2/246). The study, which was funded by the Department for Food and Rural Affairs (Defra), was undertaken by the Food...... the significance of the drinking water exposure route compared to other routes of exposure. Risk was examined in the sense of likelihood of exposure to nanoparticles via drinking water; analysis of health risks was beyond the scope of the project. The first stage of the study consisted of a detailed review...

  12. Solution for Ill-Posed Inverse Kinematics of Robot Arm by Network Inversion

    Directory of Open Access Journals (Sweden)

    Takehiko Ogawa

    2010-01-01

    Full Text Available In the context of controlling a robot arm with multiple joints, the method of estimating the joint angles from the given end-effector coordinates is called inverse kinematics, which is a type of inverse problems. Network inversion has been proposed as a method for solving inverse problems by using a multilayer neural network. In this paper, network inversion is introduced as a method to solve the inverse kinematics problem of a robot arm with multiple joints, where the joint angles are estimated from the given end-effector coordinates. In general, inverse problems are affected by ill-posedness, which implies that the existence, uniqueness, and stability of their solutions are not guaranteed. In this paper, we show the effectiveness of applying network inversion with regularization, by which ill-posedness can be reduced, to the ill-posed inverse kinematics of an actual robot arm with multiple joints.

  13. Pose estimation and tracking of non-cooperative rocket bodies using Time-of-Flight cameras

    Science.gov (United States)

    Gómez Martínez, Harvey; Giorgi, Gabriele; Eissfeller, Bernd

    2017-10-01

    This paper presents a methodology for estimating the position and orientation of a rocket body in orbit - the target - undergoing a roto-translational motion, with respect to a chaser spacecraft, whose task is to match the target dynamics for a safe rendezvous. During the rendezvous maneuver the chaser employs a Time-of-Flight camera that acquires a point cloud of 3D coordinates mapping the sensed target surface. Once the system identifies the target, it initializes the chaser-to-target relative position and orientation. After initialization, a tracking procedure enables the system to sense the evolution of the target's pose between frames. The proposed algorithm is evaluated using simulated point clouds, generated with a CAD model of the Cosmos-3M upper stage and the PMD CamCube 3.0 camera specifications.

  14. A monocular vision system based on cooperative targets detection for aircraft pose measurement

    Science.gov (United States)

    Wang, Zhenyu; Wang, Yanyun; Cheng, Wei; Chen, Tao; Zhou, Hui

    2017-08-01

    In this paper, a monocular vision measurement system based on cooperative targets detection is proposed, which can capture the three-dimensional information of objects by recognizing the checkerboard target and calculating of the feature points. The aircraft pose measurement is an important problem for aircraft’s monitoring and control. Monocular vision system has a good performance in the range of meter. This paper proposes an algorithm based on coplanar rectangular feature to determine the unique solution of distance and angle. A continuous frame detection method is presented to solve the problem of corners’ transition caused by symmetry of the targets. Besides, a displacement table test system based on three-dimensional precision and measurement system human-computer interaction software has been built. Experiment result shows that it has a precision of 2mm in the range of 300mm to 1000mm, which can meet the requirement of the position measurement in the aircraft cabin.

  15. Newton-Type Iteration for Tikhonov Regularization of Nonlinear Ill-Posed Problems

    Directory of Open Access Journals (Sweden)

    Santhosh George

    2013-01-01

    Full Text Available Recently in the work of George, 2010, we considered a modified Gauss-Newton method for approximate solution of a nonlinear ill-posed operator equation F(x=y, where F:D(F⊆X→Y is a nonlinear operator between the Hilbert spaces X and Y. The analysis in George, 2010 was carried out using a majorizing sequence. In this paper, we consider also the modified Gauss-Newton method, but the convergence analysis and the error estimate are obtained by analyzing the odd and even terms of the sequence separately. We use the adaptive method in the work of Pereverzev and Schock, 2005 for choosing the regularization parameter. The optimality of this method is proved under a general source condition. A numerical example of nonlinear integral equation shows the performance of this procedure.

  16. The "mental feature" in mental illness: difficulties that this reality poses for diagnosis and classification

    Directory of Open Access Journals (Sweden)

    Humberto L. Casarotti

    2013-01-01

    Full Text Available Four points are considered in this article. In the first place, it is argued that the "settings" of psychiatric care express the need to respond to the degree of decrease in personal freedom of the patient. Then, the issue of how "the mental feature" of the mental pathology has been recognized and categorized since the 18th century is examined, pointing out the difficulties involved in considering the mental nature of the subject of psychiatry. In the third place, the issue of how current systems of diagnosis and classification are posed regarding this reality is briefly looked at. Finally, the characteristics of a working hypothesis that allows organizing consistent clinical facts providing a heuristic perspective are analyzed.

  17. STS-88 Mission Specialist Krikalev poses in white room during TCDT

    Science.gov (United States)

    1998-01-01

    STS-88 Mission Specialist Sergei Konstantinovich Krikalev poses for a photograph in the white room on Launch Pad 39A while taking part in Terminal Countdown Demonstration Test (TCDT) activities. The TCDT provides the crew with simulated countdown exercises, emergency egress training, and opportunities to inspect their mission payloads in the orbiter's payload bay. This will be Krikalev's second space flight. Others in the STS-88 crew are Mission Commander Robert D. Cabana, Pilot Frederick W. 'Rick' Sturckow, Mission Specialists Nancy J. Currie, Jerry L. Ross, and James H. Newman. Mission STS-88 is targeted for launch on Dec. 3, 1998. It is the first U.S. flight for the assembly of the International Space Station and will carry the Unity connecting module.

  18. A scheme to analyses the statements of the student in context of problem posing

    Directory of Open Access Journals (Sweden)

    Johan Espinoza-González

    2015-01-01

    Full Text Available The problem posing is considered as an important activity in the formation of mathematical skills of students, so they have made efforts to study it as a process of instruction in math classes; however, few investigations addressed strategies designed to assess student productions at this type of task. Thus, the construction and implementation of a analyses scheme that was used in a broader research study that aimed to characterize the arithmetic performance of a group of talented students in mathematics is presented. To do an analysis of the study variables of arithmetic problems and a study of the tools used in previous research was conducted, which allowed define three categories of analysis and in each study variables. The results show the feasibility of such a scheme to characterize the problems invented by students, identify different levels of complexity in the same and to assess the degree of profundity and appropriation of the knowledge learned.

  19. Pose and Expression Independent Facial Landmark Localization Using Dense-SURF and the Hausdorff Distance.

    Science.gov (United States)

    Sangineto, Enver

    2013-03-01

    We present an approach to automatic localization of facial feature points which deals with pose, expression, and identity variations combining 3D shape models with local image patch classification. The latter is performed by means of densely extracted SURF-like features, which we call DU-SURF, while the former is based on a multiclass version of the Hausdorff distance to address local classification errors and nonvisible points. The final system is able to localize facial points in real-world scenarios, dealing with out of plane head rotations, expression changes, and different lighting conditions. Extensive experimentation with the proposed method has been carried out showing the superiority of our approach with respect to other state-of-the-art systems. Finally, DU-SURF features have been compared with other modern features and we experimentally demonstrate their competitive classification accuracy and computational efficiency.

  20. Accurate and Well-posed Absorbing Boundary Conditions for Anisotropic Media

    Science.gov (United States)

    Savadatti, Siddharth

    This dissertation provides (a) an accurate and well-posed local absorbing boundary condition (ABC) for time-dependent modeling of propagating waves in tilted anisotropic acoustic media, (b) an accurate local ABC for time-harmonic modeling of both propagating and evanescent anti-plane and in-plane waves in tilted elliptic anisotropic elastic media, and (c) an accurate local ABC for time-harmonic modeling of in-plane propagating waves in untilted non-elliptic anisotropic elastic media. Such media support wavemodes with opposing signs of phase (cpx) and group (cgx) velocities that have long posed a significant challenge to the design of accurate, well-posed and stable local ABCs. By specifically considering the recently developed local ABC, the perfectly matched discrete layer (PMDL), we show that a careful choice of parameters can result in an effective local ABC for anisotropic media. We first consider a PMDL with real-valued parameters designed to absorb the propagating wavemodes of tilted anisotropic acoustics. Starting with the derivation of the reflection coefficient, we show that the PMDL absorption is based on group (not phase) velocities. The group velocity form of the reflection coefficient is used to derive a sufficient condition for PMDL to accurately absorb all outgoing wavemodes (even those with opposing signs of phase and group velocities, i.e. cpxcgx interior with PMDL, we show that the accuracy condition also ensures well-posedness. We consider next a PMDL with complex-valued parameters designed to absorb both the propagating and evanescent wavemodes of tilted elliptic anisotropic elasticity. By first considering the simpler case of scalar anti-plane shear waves, we show that it is possible to overcome the challenges posed by cpxcgx designed to absorb the propagating wavemodes of untilted non-elliptic anisotropic elasticity. While simple space-time transformations are available to treat the wavemodes with cpxcgx concept of layer grouping along with a

  1. On a Level-Set Method for Ill-Posed Problems with Piecewise Nonconstant Coefficients

    Directory of Open Access Journals (Sweden)

    A. De Cezaro

    2013-01-01

    Full Text Available We investigate a level-set-type method for solving ill-posed problems, with the assumption that the solutions are piecewise, but not necessarily constant functions with unknown level sets and unknown level values. In order to get stable approximate solutions of the inverse problem, we propose a Tikhonov-type regularization approach coupled with a level-set framework. We prove the existence of generalized minimizers for the Tikhonov functional. Moreover, we prove convergence and stability for regularized solutions with respect to the noise level, characterizing the level-set approach as a regularization method for inverse problems. We also show the applicability of the proposed level-set method in some interesting inverse problems arising in elliptic PDE models.

  2. Pose-estimation error analysis of the L-shaped line segments for object recognition

    Science.gov (United States)

    Nomura, Yoshihiko; Hirata, Junichi; Zhang, Dili

    1999-08-01

    This paper present a method to reduce the calculation costs of object pose measurements. They are estimated by matching L-shaped line-segments in 3D object models with those in 2D object images using a P3P solution. The L segments have the minimum pieces of information for the estimation, and, therefore, it produces a large amount of L segments both in the 3D object models and in the 2D object images, resulting in enormous correspondences, and P3P calculations. To solve the problem, we propose a strategy enabling to select fewer L segments: as an evaluation function, we utilizes an average of the estimation errors when observing the L segments from representative points on a geodesic dome. Furthermore, we deduce a useful approximate formula for L segments having various shapes.

  3. Pose Estimation from Line Correspondences: A Complete Analysis and a Series of Solutions.

    Science.gov (United States)

    Xu, Chi; Zhang, Lilian; Cheng, Li; Koch, Reinhard

    2017-06-01

    In this paper we deal with the camera pose estimation problem from a set of 2D/3D line correspondences, which is also known as PnL (Perspective-n-Line) problem. We carry out our study by comparing PnL with the well-studied PnP (Perspective-n-Point) problem, and our contributions are three-fold: (1) We provide a complete 3D configuration analysis for P3L, which includes the well-known P3P problem as well as several existing analyses as special cases. (2) By exploring the similarity between PnL and PnP, we propose a new subset-based PnL approach as well as a series of linear-formulation-based PnL approaches inspired by their PnP counterparts. (3) The proposed linear-formulation-based methods can be easily extended to deal with the line and point features simultaneously.

  4. Real-time Pipeline for Object Modeling and Grasping Pose Selection via Superquadric Functions

    Directory of Open Access Journals (Sweden)

    Giulia Vezzani

    2017-11-01

    Full Text Available This work provides a novel real-time pipeline for modeling and grasping of unknown objects with a humanoid robot. Such a problem is of great interest for the robotic community, since conventional approaches fail when the shape, dimension, or pose of the objects are missing. Our approach reconstructs in real-time a model for the object under consideration and represents the robot hand both with proper and mathematically usable models, i.e., superquadric functions. The volume graspable by the hand is represented by an ellipsoid and is defined a priori, because the shape of the hand is known in advance. The superquadric representing the object is obtained in real-time from partial vision information instead, e.g., one stereo view of the object under consideration, and provides an approximated 3D full model. The optimization problem we formulate for the grasping pose computation is solved online by using the Ipopt software package and, thus, does not require off-line computation or learning. Even though our approach is for a generic humanoid robot, we developed a complete software architecture for executing this approach on the iCub humanoid robot. Together with that, we also provide a tutorial on how to use this framework. We believe that our work, together with the available code, is of a strong utility for the iCub community for three main reasons: object modeling and grasping are relevant problems for the robotic community, our code can be easily applied on every iCub, and the modular structure of our framework easily allows extensions and communications with external code.

  5. Is Attribute-Based Zero-Shot Learning an Ill-Posed Strategy?

    KAUST Repository

    Alabdulmohsin, Ibrahim

    2016-09-03

    One transfer learning approach that has gained a wide popularity lately is attribute-based zero-shot learning. Its goal is to learn novel classes that were never seen during the training stage. The classical route towards realizing this goal is to incorporate a prior knowledge, in the form of a semantic embedding of classes, and to learn to predict classes indirectly via their semantic attributes. Despite the amount of research devoted to this subject lately, no known algorithm has yet reported a predictive accuracy that could exceed the accuracy of supervised learning with very few training examples. For instance, the direct attribute prediction (DAP) algorithm, which forms a standard baseline for the task, is known to be as accurate as supervised learning when as few as two examples from each hidden class are used for training on some popular benchmark datasets! In this paper, we argue that this lack of significant results in the literature is not a coincidence; attribute-based zero-shot learning is fundamentally an ill-posed strategy. The key insight is the observation that the mechanical task of predicting an attribute is, in fact, quite different from the epistemological task of learning the “correct meaning” of the attribute itself. This renders attribute-based zero-shot learning fundamentally ill-posed. In more precise mathematical terms, attribute-based zero-shot learning is equivalent to the mirage goal of learning with respect to one distribution of instances, with the hope of being able to predict with respect to any arbitrary distribution. We demonstrate this overlooked fact on some synthetic and real datasets. The data and software related to this paper are available at https://mine. kaust.edu.sa/Pages/zero-shot-learning.aspx. © Springer International Publishing AG 2016.

  6. Evaluation of DOCK 6 as a pose generation and database enrichment tool.

    Science.gov (United States)

    Brozell, Scott R; Mukherjee, Sudipto; Balius, Trent E; Roe, Daniel R; Case, David A; Rizzo, Robert C

    2012-06-01

    In conjunction with the recent American Chemical Society symposium titled "Docking and Scoring: A Review of Docking Programs" the performance of the DOCK6 program was evaluated through (1) pose reproduction and (2) database enrichment calculations on a common set of organizer-specified systems and datasets (ASTEX, DUD, WOMBAT). Representative baseline grid score results averaged over five docking runs yield a relatively high pose identification success rate of 72.5 % (symmetry corrected rmsd) and sampling rate of 91.9 % for the multi site ASTEX set (N = 147) using organizer-supplied structures. Numerous additional docking experiments showed that ligand starting conditions, symmetry, multiple binding sites, clustering, and receptor preparation protocols all affect success. Encouragingly, in some cases, use of more sophisticated scoring and sampling methods yielded results which were comparable (Amber score ligand movable protocol) or exceeded (LMOD score) analogous baseline grid-score results. The analysis highlights the potential benefit and challenges associated with including receptor flexibility and indicates that different scoring functions have system dependent strengths and weaknesses. Enrichment studies with the DUD database prepared using the SB2010 preparation protocol and native ligand pairings yielded individual area under the curve (AUC) values derived from receiver operating characteristic curve analysis ranging from 0.29 (bad enrichment) to 0.96 (good enrichment) with an average value of 0.60 (27/38 have AUC ≥ 0.5). Strong early enrichment was also observed in the critically important 1.0-2.0 % region. Somewhat surprisingly, an alternative receptor preparation protocol yielded comparable results. As expected, semi-random pairings yielded poorer enrichments, in particular, for unrelated receptors. Overall, the breadth and number of experiments performed provide a useful snapshot of current capabilities of DOCK6 as well as starting points to

  7. Ill-posed problem and regularization in reconstruction of radiobiological parameters from serial tumor imaging data

    Science.gov (United States)

    Chvetsov, Alevei V.; Sandison, George A.; Schwartz, Jeffrey L.; Rengan, Ramesh

    2015-11-01

    The main objective of this article is to improve the stability of reconstruction algorithms for estimation of radiobiological parameters using serial tumor imaging data acquired during radiation therapy. Serial images of tumor response to radiation therapy represent a complex summation of several exponential processes as treatment induced cell inactivation, tumor growth rates, and the rate of cell loss. Accurate assessment of treatment response would require separation of these processes because they define radiobiological determinants of treatment response and, correspondingly, tumor control probability. However, the estimation of radiobiological parameters using imaging data can be considered an inverse ill-posed problem because a sum of several exponentials would produce the Fredholm integral equation of the first kind which is ill posed. Therefore, the stability of reconstruction of radiobiological parameters presents a problem even for the simplest models of tumor response. To study stability of the parameter reconstruction problem, we used a set of serial CT imaging data for head and neck cancer and a simplest case of a two-level cell population model of tumor response. Inverse reconstruction was performed using a simulated annealing algorithm to minimize a least squared objective function. Results show that the reconstructed values of cell surviving fractions and cell doubling time exhibit significant nonphysical fluctuations if no stabilization algorithms are applied. However, after applying a stabilization algorithm based on variational regularization, the reconstruction produces statistical distributions for survival fractions and doubling time that are comparable to published in vitro data. This algorithm is an advance over our previous work where only cell surviving fractions were reconstructed. We conclude that variational regularization allows for an increase in the number of free parameters in our model which enables development of more

  8. Allocation Games: Addressing the Ill-Posed Nature of Allocation in Life-Cycle Inventories.

    Science.gov (United States)

    Hanes, Rebecca J; Cruze, Nathan B; Goel, Prem K; Bakshi, Bhavik R

    2015-07-07

    Allocation is required when a life cycle contains multi-functional processes. One approach to allocation is to partition the embodied resources in proportion to a criterion, such as product mass or cost. Many practitioners apply multiple partitioning criteria to avoid choosing one arbitrarily. However, life cycle results from different allocation methods frequently contradict each other, making it difficult or impossible for the practitioner to draw any meaningful conclusions from the study. Using the matrix notation for life-cycle inventory data, we show that an inventory that requires allocation leads to an ill-posed problem: an inventory based on allocation is one of an infinite number of inventories that are highly dependent upon allocation methods. This insight is applied to comparative life-cycle assessment (LCA), in which products with the same function but different life cycles are compared. Recently, there have been several studies that applied multiple allocation methods and found that different products were preferred under different methods. We develop the Comprehensive Allocation Investigation Strategy (CAIS) to examine any given inventory under all possible allocation decisions, enabling us to detect comparisons that are not robust to allocation, even when the comparison appears robust under conventional partitioning methods. While CAIS does not solve the ill-posed problem, it provides a systematic way to parametrize and examine the effects of partitioning allocation. The practical usefulness of this approach is demonstrated with two case studies. The first compares ethanol produced from corn stover hydrolysis, corn stover gasification, and corn grain fermentation. This comparison was not robust to allocation. The second case study compares 1,3-propanediol (PDO) produced from fossil fuels and from biomass, which was found to be a robust comparison.

  9. Precise 3D Lug Pose Detection Sensor for Automatic Robot Welding Using a Structured-Light Vision System

    National Research Council Canada - National Science Library

    Park, Jae Byung; Lee, Seung Hun; Lee, Il Jae

    2009-01-01

    In this study, we propose a precise 3D lug pose detection sensor for automatic robot welding of a lug to a huge steel plate used in shipbuilding, where the lug is a handle to carry the huge steel plate...

  10. Head Pose Estimation on Top of Haar-Like Face Detection: A Study Using the Kinect Sensor

    National Research Council Canada - National Science Library

    Saeed, Anwar; Al-Hamadi, Ayoub; Ghoneim, Ahmed

    2015-01-01

    ..., such as: facial expression recognition, head gesture recognition, yawn detection, etc. In this work, we propose a frame-based approach to estimate the head pose on top of the Viola and Jones (VJ...

  11. Intelligent Control of Welding Gun Pose for Pipeline Welding Robot Based on Improved Radial Basis Function Network and Expert System

    OpenAIRE

    Jingwen Tian; Meijuan Gao; Yonggang He

    2013-01-01

    Since the control system of the welding gun pose in whole‐position welding is complicated and nonlinear, an intelligent control system of welding gun pose for a pipeline welding robot based on an improved radial basis function neural network (IRBFNN) and expert system (ES) is presented in this paper. The structure of the IRBFNN is constructed and the improved genetic algorithm is adopted to optimize the network structure. This control system makes full use of the characteristics of the IRBFNN...

  12. Yoga Poses Increase Subjective Energy and State Self-Esteem in Comparison to ‘Power Poses’

    OpenAIRE

    Golec de Zavala, Agnieszka; Lantos, Dorottya; Bowden, Deborah

    2017-01-01

    Research on beneficial consequences of yoga focuses on the effects of yogic breathing and meditation. Less is known about the psychological effects of performing yoga postures. The present study investigated the effects of yoga poses on subjective sense of energy and self-esteem. The effects of yoga postures were compared to the effects of ‘power poses,’ which arguably increase the sense of power and self-confidence due to their association with interpersonal dominance (Carney et al., 2010). ...

  13. Precise 3D Lug Pose Detection Sensor for Automatic Robot Welding Using a Structured-Light Vision System

    Directory of Open Access Journals (Sweden)

    Il Jae Lee

    2009-09-01

    Full Text Available In this study, we propose a precise 3D lug pose detection sensor for automatic robot welding of a lug to a huge steel plate used in shipbuilding, where the lug is a handle to carry the huge steel plate. The proposed sensor consists of a camera and four laser line diodes, and its design parameters are determined by analyzing its detectable range and resolution. For the lug pose acquisition, four laser lines are projected on both lug and plate, and the projected lines are detected by the camera. For robust detection of the projected lines against the illumination change, the vertical threshold, thinning, Hough transform and separated Hough transform algorithms are successively applied to the camera image. The lug pose acquisition is carried out by two stages: the top view alignment and the side view alignment. The top view alignment is to detect the coarse lug pose relatively far from the lug, and the side view alignment is to detect the fine lug pose close to the lug. After the top view alignment, the robot is controlled to move close to the side of the lug for the side view alignment. By this way, the precise 3D lug pose can be obtained. Finally, experiments with the sensor prototype are carried out to verify the feasibility and effectiveness of the proposed sensor.

  14. IMU-based Real-time Pose Measurement system for Anterior Pelvic Plane in Total Hip Replacement Surgeries.

    Science.gov (United States)

    Zhe Cao; Shaojie Su; Hao Tang; Yixin Zhou; Zhihua Wang; Hong Chen

    2017-07-01

    With the aging of population, the number of Total Hip Replacement Surgeries (THR) increased year by year. In THR, inaccurate position of the implanted prosthesis may lead to the failure of the operation. In order to reduce the failure rate and acquire the real-time pose of Anterior Pelvic Plane (APP), we propose a measurement system in this paper. The measurement system includes two parts: Initial Pose Measurement Instrument (IPMI) and Real-time Pose Measurement Instrument (RPMI). IPMI is used to acquire the initial pose of the APP, and RPMI is used to estimate the real-time pose of the APP. Both are composed of an Inertial Measurement Unit (IMU) and magnetometer sensors. To estimate the attitude of the measurement system, the Extended Kalman Filter (EKF) is adopted in this paper. The real-time pose of the APP could be acquired together with the algorithm designed in the paper. The experiment results show that the Root Mean Square Error (RMSE) is within 1.6 degrees, which meets the requirement of THR operations.

  15. Head Pose Estimation on Top of Haar-Like Face Detection: A Study Using the Kinect Sensor

    Directory of Open Access Journals (Sweden)

    Anwar Saeed

    2015-08-01

    Full Text Available Head pose estimation is a crucial initial task for human face analysis, which is employed in several computer vision systems, such as: facial expression recognition, head gesture recognition, yawn detection, etc. In this work, we propose a frame-based approach to estimate the head pose on top of the Viola and Jones (VJ Haar-like face detector. Several appearance and depth-based feature types are employed for the pose estimation, where comparisons between them in terms of accuracy and speed are presented. It is clearly shown through this work that using the depth data, we improve the accuracy of the head pose estimation. Additionally, we can spot positive detections, faces in profile views detected by the frontal model, that are wrongly cropped due to background disturbances. We introduce a new depth-based feature descriptor that provides competitive estimation results with a lower computation time. Evaluation on a benchmark Kinect database shows that the histogram of oriented gradients and the developed depth-based features are more distinctive for the head pose estimation, where they compare favorably to the current state-of-the-art approaches. Using a concatenation of the aforementioned feature types, we achieved a head pose estimation with average errors not exceeding 5:1; 4:6; 4:2 for pitch, yaw and roll angles, respectively.

  16. Enrichment and assessment of the health risks posed by heavy metals in PM1 in Changji, Xinjiang, China.

    Science.gov (United States)

    Liu, Yu Y; Shen, Ya X; Liu, Cheng; Liu, Hao F

    2017-04-16

    The present study aims to investigate the influence of human activity on heavy metals in a typical arid urban area of China and assess human health risks posed by heavy metals in PM1 (particles metals. The results indicated that Mn was not enriched; Co, Cu, Cr, Ni, Tl, and V were slightly enriched; Mo, Pb, and Sb were moderately enriched; and Ag, As, and Cd were strongly enriched. To assess the health risks associated with inhaling PM1, the risk assessment code and loss in life expectancy based on the individual metals were calculated. The results showed that the elements Ag, Cu, Mo, Pb, Sb, Tl, and V in PM1 posed low levels of non-carcinogenic risks, but these metals may still pose risks to certain susceptible populations. In addition, the results also showed that As, Co, and Cr posed an appreciable carcinogenic risk, while Cd and Ni posed low levels of carcinogenic risk. The total predicted loss of life expectancy caused by the three metals As, Co, and Ni was 63.67 d for the elderly, 30.95 d for adult males, 26.62 d for adult females, and 48.22 d for children. Therefore, the safety of the elderly and children exposed to PM1 should be given more attention than the safety of adults. The results from this study demonstrate that the health risks posed by heavy metals in PM1 in Changji, Xinjiang, China should be examined.

  17. Head Pose Estimation on Top of Haar-Like Face Detection: A Study Using the Kinect Sensor.

    Science.gov (United States)

    Saeed, Anwar; Al-Hamadi, Ayoub; Ghoneim, Ahmed

    2015-08-26

    Head pose estimation is a crucial initial task for human face analysis, which is employed in several computer vision systems, such as: facial expression recognition, head gesture recognition, yawn detection, etc. In this work, we propose a frame-based approach to estimate the head pose on top of the Viola and Jones (VJ) Haar-like face detector. Several appearance and depth-based feature types are employed for the pose estimation, where comparisons between them in terms of accuracy and speed are presented. It is clearly shown through this work that using the depth data, we improve the accuracy of the head pose estimation. Additionally, we can spot positive detections, faces in profile views detected by the frontal model, that are wrongly cropped due to background disturbances. We introduce a new depth-based feature descriptor that provides competitive estimation results with a lower computation time. Evaluation on a benchmark Kinect database shows that the histogram of oriented gradients and the developed depth-based features are more distinctive for the head pose estimation, where they compare favorably to the current state-of-the-art approaches. Using a concatenation of the aforementioned feature types, we achieved a head pose estimation with average errors not exceeding 5:1; 4:6; 4:2 for pitch, yaw and roll angles, respectively.

  18. Precise 3D Lug Pose Detection Sensor for Automatic Robot Welding Using a Structured-Light Vision System.

    Science.gov (United States)

    Park, Jae Byung; Lee, Seung Hun; Lee, Il Jae

    2009-01-01

    In this study, we propose a precise 3D lug pose detection sensor for automatic robot welding of a lug to a huge steel plate used in shipbuilding, where the lug is a handle to carry the huge steel plate. The proposed sensor consists of a camera and four laser line diodes, and its design parameters are determined by analyzing its detectable range and resolution. For the lug pose acquisition, four laser lines are projected on both lug and plate, and the projected lines are detected by the camera. For robust detection of the projected lines against the illumination change, the vertical threshold, thinning, Hough transform and separated Hough transform algorithms are successively applied to the camera image. The lug pose acquisition is carried out by two stages: the top view alignment and the side view alignment. The top view alignment is to detect the coarse lug pose relatively far from the lug, and the side view alignment is to detect the fine lug pose close to the lug. After the top view alignment, the robot is controlled to move close to the side of the lug for the side view alignment. By this way, the precise 3D lug pose can be obtained. Finally, experiments with the sensor prototype are carried out to verify the feasibility and effectiveness of the proposed sensor.

  19. Performance of multiple docking and refinement methods in the pose prediction D3R prospective Grand Challenge 2016

    Science.gov (United States)

    Fradera, Xavier; Verras, Andreas; Hu, Yuan; Wang, Deping; Wang, Hongwu; Fells, James I.; Armacost, Kira A.; Crespo, Alejandro; Sherborne, Brad; Wang, Huijun; Peng, Zhengwei; Gao, Ying-Duo

    2017-09-01

    We describe the performance of multiple pose prediction methods for the D3R 2016 Grand Challenge. The pose prediction challenge includes 36 ligands, which represent 4 chemotypes and some miscellaneous structures against the FXR ligand binding domain. In this study we use a mix of fully automated methods as well as human-guided methods with considerations of both the challenge data and publicly available data. The methods include ensemble docking, colony entropy pose prediction, target selection by molecular similarity, molecular dynamics guided pose refinement, and pose selection by visual inspection. We evaluated the success of our predictions by method, chemotype, and relevance of publicly available data. For the overall data set, ensemble docking, visual inspection, and molecular dynamics guided pose prediction performed the best with overall mean RMSDs of 2.4, 2.2, and 2.2 Å respectively. For several individual challenge molecules, the best performing method is evaluated in light of that particular ligand. We also describe the protein, ligand, and public information data preparations that are typical of our binding mode prediction workflow.

  20. Molds and mycotoxins in poultry feeds from farms of potential mycotoxicosis

    Directory of Open Access Journals (Sweden)

    A. M. Shareef

    2010-01-01

    Full Text Available Forty five finished poultry feed samples, collected from different broilers, broiler breeders and layers farms were divided into two parts, for mycological and mycotoxins examination. In counting of molds, dilute plate technique was used, whereas feed parts were used for mycotoxin estimation, they were subjected to four standard kits of Aflatoxin, Ochratoxin, T-2 toxin and Fumonisins. Mold counts were around 105 cfu.g-1 sample. Fourteen mold genera were recovered. From the systematic point of view, 2 genera belonged to Zygomycetes (i.e. Mucor, Rhizopus,, 1 genus belong to Ascomycetes (i.e. Eurotium; the majority, within so-called mitotic fungi (formerly Deuteromycetes, encompassed 11 genera (i.e. Acremonium, Alternaria, Aspergillus, Fusarium, Paecilomyces, Penicillium, Scopulariopsis,, Trichothecium, Ulocladium and Aerobasidium. The most frequent fungi were those from the genus Aspergillus. The concentrations of the four analyzed mycotoxins in the poultry finished feeds, and the percentages of the recovered mycotoxins, revealed that aflatoxins was recovered in 91.1% of the examined samples, with a mean value of 179.1µg/kg. The same percentage was found with Ochratoxins, but with lower mean concentration of 159.4µg/kg. In the third order were Fumonisins mycotoxins were in the third order, and they were recovered in 51.1% of the tested samples with a mean value of 127µg/kg. In the fourth order was T-2 toxin, with a percentage of 2.2% and a value of 50.0µg/kg.

  1. Using physics-based pose predictions and free energy perturbation calculations to predict binding poses and relative binding affinities for FXR ligands in the D3R Grand Challenge 2

    Science.gov (United States)

    Athanasiou, Christina; Vasilakaki, Sofia; Dellis, Dimitris; Cournia, Zoe

    2017-11-01

    Computer-aided drug design has become an integral part of drug discovery and development in the pharmaceutical and biotechnology industry, and is nowadays extensively used in the lead identification and lead optimization phases. The drug design data resource (D3R) organizes challenges against blinded experimental data to prospectively test computational methodologies as an opportunity for improved methods and algorithms to emerge. We participated in Grand Challenge 2 to predict the crystallographic poses of 36 Farnesoid X Receptor (FXR)-bound ligands and the relative binding affinities for two designated subsets of 18 and 15 FXR-bound ligands. Here, we present our methodology for pose and affinity predictions and its evaluation after the release of the experimental data. For predicting the crystallographic poses, we used docking and physics-based pose prediction methods guided by the binding poses of native ligands. For FXR ligands with known chemotypes in the PDB, we accurately predicted their binding modes, while for those with unknown chemotypes the predictions were more challenging. Our group ranked #1st (based on the median RMSD) out of 46 groups, which submitted complete entries for the binding pose prediction challenge. For the relative binding affinity prediction challenge, we performed free energy perturbation (FEP) calculations coupled with molecular dynamics (MD) simulations. FEP/MD calculations displayed a high success rate in identifying compounds with better or worse binding affinity than the reference (parent) compound. Our studies suggest that when ligands with chemical precedent are available in the literature, binding pose predictions using docking and physics-based methods are reliable; however, predictions are challenging for ligands with completely unknown chemotypes. We also show that FEP/MD calculations hold predictive value and can nowadays be used in a high throughput mode in a lead optimization project provided that crystal structures of

  2. Using physics-based pose predictions and free energy perturbation calculations to predict binding poses and relative binding affinities for FXR ligands in the D3R Grand Challenge 2.

    Science.gov (United States)

    Athanasiou, Christina; Vasilakaki, Sofia; Dellis, Dimitris; Cournia, Zoe

    2018-01-01

    Computer-aided drug design has become an integral part of drug discovery and development in the pharmaceutical and biotechnology industry, and is nowadays extensively used in the lead identification and lead optimization phases. The drug design data resource (D3R) organizes challenges against blinded experimental data to prospectively test computational methodologies as an opportunity for improved methods and algorithms to emerge. We participated in Grand Challenge 2 to predict the crystallographic poses of 36 Farnesoid X Receptor (FXR)-bound ligands and the relative binding affinities for two designated subsets of 18 and 15 FXR-bound ligands. Here, we present our methodology for pose and affinity predictions and its evaluation after the release of the experimental data. For predicting the crystallographic poses, we used docking and physics-based pose prediction methods guided by the binding poses of native ligands. For FXR ligands with known chemotypes in the PDB, we accurately predicted their binding modes, while for those with unknown chemotypes the predictions were more challenging. Our group ranked #1st (based on the median RMSD) out of 46 groups, which submitted complete entries for the binding pose prediction challenge. For the relative binding affinity prediction challenge, we performed free energy perturbation (FEP) calculations coupled with molecular dynamics (MD) simulations. FEP/MD calculations displayed a high success rate in identifying compounds with better or worse binding affinity than the reference (parent) compound. Our studies suggest that when ligands with chemical precedent are available in the literature, binding pose predictions using docking and physics-based methods are reliable; however, predictions are challenging for ligands with completely unknown chemotypes. We also show that FEP/MD calculations hold predictive value and can nowadays be used in a high throughput mode in a lead optimization project provided that crystal structures of

  3. What threat do turbidity currents and submarine landslides pose to submarine telecommunications cable infrastructure?

    Science.gov (United States)

    Clare, Michael; Pope, Edward; Talling, Peter; Hunt, James; Carter, Lionel

    2016-04-01

    The global economy relies on uninterrupted usage of a network of telecommunication cables on the seafloor. These submarine cables carry ~99% of all trans-oceanic digital data and voice communications traffic worldwide, as they have far greater bandwidth than satellites. Over 9 million SWIFT banks transfers alone were made using these cables in 2004, totalling 7.4 trillion of transactions per day between 208 countries, which grew to 15 million SWIFT bank transactions last year. We outline the challenge of why, how often, and where seafloor cables are broken by natural causes; primarily subsea landslides and sediment flows (turbidity currents and also debris flows and hyperpycnal flows). These slides and flows can be very destructive. As an example, a sediment flow in 1929 travelled up to 19 m/s and broke 11 cables in the NE Atlantic, running out for ~800 km to the abyssal ocean. The 2006 Pingtung earthquake triggered a sediment flow that broke 22 cables offshore Taiwan over a distance of 450 km. Here, we present initial results from the first statistical analysis of a global database of cable breaks and causes. We first investigate the controls on frequency of submarine cable breaks in different environmental and geological settings worldwide. We assess which types of earthquake pose a significant threat to submarine cable networks. Meteorological events, such as hurricanes and typhoons, pose a significant threat to submarine cable networks, so we also discuss the potential impacts of future climate change on the frequency of such hazards. We then go on to ask what are the physical impacts of submarine sediment flows on submerged cables? A striking observation from past cable breaks is sometimes cables remain unbroken, whilst adjacent cables are severed (and record powerful flows travelling at up to 6 m/s). Why are some cables broken, but neighbouring cables remain intact? We provide some explanations for this question, and outline the need for future in

  4. New insight into bacterial zoonotic pathogens posing health hazards to humans

    Directory of Open Access Journals (Sweden)

    Marcin Ciszewski

    2014-12-01

    Full Text Available This article presents the problem of evolutionary changes of zoonotic pathogens responsible for human diseases. Everyone is exposed to the risk of zoonotic infection, particularly employees having direct contact with animals, i.e. veterinarians, breeders, butchers and workers of animal products’ processing industry. The article focuses on pathogens monitored by the European Centre for Disease Prevention and Control (ECDC, which has been collecting statistical data on zoonoses from all European Union countries for 19 years and publishing collected data in annual epidemiological reports. Currently, the most important 11 pathogens responsible for causing human zoonotic diseases are being monitored, of which seven are bacteria: Salmonella spp., Campylobacter spp., Listeria monocytogenes, Mycobacterium bovis, Brucella spp., Coxiella burnetti and Verotoxin- producing E. coli (VTEC / Shiga-like toxin producing E. coli (STEC. As particularly important are considered foodborne pathogens. The article also includes new emerging zoonotic bacteria, which are not currently monitored by ECDC but might pose a serious epidemiological problem in a foreseeable future: Streptococcus iniae, S. suis, S. dysgalactiae and staphylococci: Staphylococcus intermedius, S. pseudintermedius. Those species have just crossed the animal-human interspecies barrier. The exact mechanism of this phenomenon remains unknown, it is connected, however, with genetic variability, capability to survive in changing environment. These abilities derive from DNA rearrangement and horizontal gene transfer between bacterial cells. Substantial increase in the number of scientific publications on this subject, observed over the last few years, illustrates the importance of the problem. Med Pr 2014;65(6:819–829

  5. STS-103 crew poses for a photo in front of Discovery after landing

    Science.gov (United States)

    1999-01-01

    After landing at the Shuttle Landing Facility, the STS-103 crew poses in front of the orbiter Discovery. Standing left to right are Commander Curtis L. Brown Jr., Mission Specialist Claude Nicollier of Switzerland, Pilot Scott J. Kelly, and Mission Specialists Jean-Francois Clervoy of France, C. Michael Foale (Ph.D.), John M. Grunsfeld (Ph.D.) and Steven L. Smith. The crew of seven completed a successful eight-day mission to service the Hubble Space Telescope, spending the Christmas holiday in space in order to accomplish their mission before the end of 1999. During the mission, Discovery's four space-walking astronauts, Smith, Foale, Grunsfeld and Nicollier, spent 24 hours and 33 minutes upgrading and refurbishing Hubble, making it more capable than ever to renew its observations of the universe. Mission objectives included replacing gyroscopes and an old computer, installing another solid state recorder, and replacing damaged insulation in the telescope. Hubble was released from the end of Discovery's robot arm on Christmas Day. Main gear touchdown was at 7:00:47 p.m. EST. Nose gear touchdown occurred at 7:00:58 EST and wheel stop at 7:01:34 EST. This was the 96th flight in the Space Shuttle program and the 27th for the orbiter Discovery. The landing was the 20th consecutive Shuttle landing in Florida and the 13th night landing in Shuttle program history.

  6. STS-103 crew members and their families pose for a portrait before DEPARTing

    Science.gov (United States)

    1999-01-01

    The STS-103 crew pose for a group portrait with their families and loved ones on the runway at Patrick Air Force Base in Cocoa Beach, Fla. They are preparing to board an airplane that will return them to their home base at the Johnson Space Center in Houston following the successful completion of their mission. From left to right, the crew members are Mission Specialists John M. Grunsfeld (Ph.D.), C. Michael Foale (Ph.D.), Claude Nicollier of Switzerland, Jean-Frangois Clervoy of France, and Steven L. Smith; Pilot Scott J. Kelly; and Commander Curtis L. Brown Jr. Discovery landed in darkness the previous evening, Dec. 27, on runway 33 at KSC's Shuttle Landing Facility at 7:00:47 p.m. EST. This was the first time that a Shuttle crew spent the Christmas holiday in space. The STS-103 mission accomplished outfitting the Hubble Space Telescope with six new gyroscopes, six new voltage/temperature improvement kits, a new onboard computer, a new solid state recorder and new data transmitter, a new fine guidance sensor along with new insulation on parts of the orbiting telescope. This was the 96th flight in the Space Shuttle program and the 27th for the orbiter Discovery.

  7. Calibrating corneal material model parameters using only inflation data: an ill-posed problem.

    Science.gov (United States)

    Kok, S; Botha, N; Inglis, H M

    2014-12-01

    Goldmann applanation tonometry (GAT) is a method used to estimate the intraocular pressure by measuring the indentation resistance of the cornea. A popular approach to investigate the sensitivity of GAT results to material and geometry variations is to perform numerical modelling using the finite element method, for which a calibrated material model is required. These material models are typically calibrated using experimental inflation data by solving an inverse problem. In the inverse problem, the underlying material constitutive behaviour is inferred from the measured macroscopic response (chamber pressure versus apical displacement). In this study, a biomechanically motivated elastic fibre-reinforced corneal material model is chosen. The inverse problem of calibrating the corneal material model parameters using only experimental inflation data is demonstrated to be ill-posed, with small variations in the experimental data leading to large differences in the calibrated model parameters. This can result in different groups of researchers, calibrating their material model with the same inflation test data, drawing vastly different conclusions about the effect of material parameters on GAT results. It is further demonstrated that multiple loading scenarios, such as inflation as well as bending, would be required to reliably calibrate such a corneal material model. Copyright © 2014 John Wiley & Sons, Ltd.

  8. The interconnected and cross-border nature of risks posed by infectious diseases

    Directory of Open Access Journals (Sweden)

    Jonathan E. Suk

    2014-10-01

    Full Text Available Infectious diseases can constitute public health emergencies of international concern when a pathogen arises, acquires new characteristics, or is deliberately released, leading to the potential for loss of human lives as well as societal disruption. A wide range of risk drivers are now known to lead to and/or exacerbate the emergence and spread of infectious disease, including global trade and travel, the overuse of antibiotics, intensive agriculture, climate change, high population densities, and inadequate infrastructures, such as water treatment facilities. Where multiple risk drivers interact, the potential impact of a disease outbreak is amplified. The varying temporal and geographic frequency with which infectious disease events occur adds yet another layer of complexity to the issue. Mitigating the emergence and spread of infectious disease necessitates mapping and prioritising the interdependencies between public health and other sectors. Conversely, during an international public health emergency, significant disruption occurs not only to healthcare systems but also to a potentially wide range of sectors, including trade, tourism, energy, civil protection, transport, agriculture, and so on. At the same time, dealing with a disease outbreak may require a range of critical sectors for support. There is a need to move beyond narrow models of risk to better account for the interdependencies between health and other sectors so as to be able to better mitigate and respond to the risks posed by emerging infectious disease.

  9. A cognitive evaluation of four online search engines for answering definitional questions posed by physicians.

    Science.gov (United States)

    Yu, Hong; Kaufman, David

    2007-01-01

    The Internet is having a profound impact on physicians' medical decision making. One recent survey of 277 physicians showed that 72% of physicians regularly used the Internet to research medical information and 51% admitted that information from web sites influenced their clinical decisions. This paper describes the first cognitive evaluation of four state-of-the-art Internet search engines: Google (i.e., Google and Scholar.Google), MedQA, Onelook, and PubMed for answering definitional questions (i.e., questions with the format of "What is X?") posed by physicians. Onelook is a portal for online definitions, and MedQA is a question answering system that automatically generates short texts to answer specific biomedical questions. Our evaluation criteria include quality of answer, ease of use, time spent, and number of actions taken. Our results show that MedQA outperforms Onelook and PubMed in most of the criteria, and that MedQA surpasses Google in time spent and number of actions, two important efficiency criteria. Our results show that Google is the best system for quality of answer and ease of use. We conclude that Google is an effective search engine for medical definitions, and that MedQA exceeds the other search engines in that it provides users direct answers to their questions; while the users of the other search engines have to visit several sites before finding all of the pertinent information.

  10. Latent-Class Hough Forests for 6 DoF Object Pose Estimation.

    Science.gov (United States)

    Tejani, Alykhan; Kouskouridas, Rigas; Doumanoglou, Andreas; Tang, Danhang; Kim, Tae-Kyun

    2018-01-01

    In this paper we present Latent-Class Hough Forests, a method for object detection and 6 DoF pose estimation in heavily cluttered and occluded scenarios. We adapt a state of the art template matching feature into a scale-invariant patch descriptor and integrate it into a regression forest using a novel template-based split function. We train with positive samples only and we treat class distributions at the leaf nodes as latent variables. During testing we infer by iteratively updating these distributions, providing accurate estimation of background clutter and foreground occlusions and, thus, better detection rate. Furthermore, as a by-product, our Latent-Class Hough Forests can provide accurate occlusion aware segmentation masks, even in the multi-instance scenario. In addition to an existing public dataset, which contains only single-instance sequences with large amounts of clutter, we have collected two, more challenging, datasets for multiple-instance detection containing heavy 2D and 3D clutter as well as foreground occlusions. We provide extensive experiments on the various parameters of the framework such as patch size, number of trees and number of iterations to infer class distributions at test time. We also evaluate the Latent-Class Hough Forests on all datasets where we outperform state of the art methods.

  11. Application of structured support vector machine backpropagation to a convolutional neural network for human pose estimation.

    Science.gov (United States)

    Witoonchart, Peerajak; Chongstitvatana, Prabhas

    2017-08-01

    In this study, for the first time, we show how to formulate a structured support vector machine (SSVM) as two layers in a convolutional neural network, where the top layer is a loss augmented inference layer and the bottom layer is the normal convolutional layer. We show that a deformable part model can be learned with the proposed structured SVM neural network by backpropagating the error of the deformable part model to the convolutional neural network. The forward propagation calculates the loss augmented inference and the backpropagation calculates the gradient from the loss augmented inference layer to the convolutional layer. Thus, we obtain a new type of convolutional neural network called an Structured SVM convolutional neural network, which we applied to the human pose estimation problem. This new neural network can be used as the final layers in deep learning. Our method jointly learns the structural model parameters and the appearance model parameters. We implemented our method as a new layer in the existing Caffe library. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Energy normalization for pose-invariant face recognition based on MRF model image matching.

    Science.gov (United States)

    Arashloo, Shervin Rahimzadeh; Kittler, Josef

    2011-06-01

    A pose-invariant face recognition system based on an image matching method formulated on MRFs is presented. The method uses the energy of the established match between a pair of images as a measure of goodness-of-match. The method can tolerate moderate global spatial transformations between the gallery and the test images and alleviate the need for geometric preprocessing of facial images by encapsulating a registration step as part of the system. It requires no training on non-frontal face images. A number of innovations, such as a dynamic block size and block shape adaptation, as well as label pruning and error pre-whitening measures have been introduced to increase the effectiveness of the approach. The experimental evaluation of the method is performed on two publicly available databases. First, the method is tested on the rotation shots of the XM2VTS data set in a verification scenario. Next, the evaluation is conducted in an identification scenario on the CMU-PIE database. The method compares favorably with the existing 2D or 3D generative model-based methods on both databases in both identification and verification scenarios.

  13. Unintended allergens in precautionary labelled and unlabelled products pose significant risks to UK allergic consumers.

    Science.gov (United States)

    Remington, B C; Baumert, J L; Blom, W M; Houben, G F; Taylor, S L; Kruizinga, A G

    2015-07-01

    Allergens in food may pose a risk to allergic consumers. While there is EU regulation for allergens present as an ingredient, this is not the case for unintended allergen presence (UAP). Food companies use precautionary allergen labels to inform allergic individuals of a potential risk from UAPs. This study investigates the risk of an allergic reaction within the milk-, wheat-, hazelnut- and peanut-allergic populations when ingesting UK foods across multiple product categories with and without precautionary allergen labelling. Allergen risk assessment using probabilistic techniques enables the estimation of the residual risk after the consumption of a product that unintentionally contains an allergen. Within this selection of UK products, the majority that tested positive for an allergen contained a concentration of allergen predicted to cause a reaction in >1% of the allergic population. The concentrations of allergens measured were greater than the VITAL(®) 2.0 action levels and would trigger precautionary allergen labelling. This was found for products both with and without precautionary allergen labelling. The results highlight the need for the food industry and regulators to adopt a transparent, risk-based approach for the communication of the risk associated with potential cross-contact that could occur in the processing facility or production chain. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Parental allergic disease before and after child birth poses similar risk for childhood allergies.

    Science.gov (United States)

    Fuertes, E; Standl, M; von Berg, A; Lehmann, I; Hoffmann, B; Bauer, C-P; Koletzko, S; Berdel, D; Heinrich, J

    2015-07-01

    Whether the strength of associations between parental and child allergic diseases differs by whether the first onset of the parental disease is before or after a child's birth has never been examined and is the aim of this study. Yearly childhood asthma, allergic rhinitis, and eczema diagnoses were longitudinally regressed against the effect of a parental disease (pre- vs post-child birth) of the same type separately for each parent using generalized estimation equations. Both a maternal and paternal history of asthma were associated with childhood asthma prevalence up to 15 years of age. Effect estimates were similar for parental asthma with first onset before and after the birth of the child. The results for allergic rhinitis and eczema were less consistent. Parental allergic diseases with first onsets before and after the birth of a child both pose risks to childhood allergic disease in the offspring, especially for asthma. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Do toxic cyanobacteria blooms pose a threat to the Baltic ecosystem?

    Directory of Open Access Journals (Sweden)

    Hanna Mazur-Marzec

    2009-09-01

    Full Text Available Cyanobacteria, otherwise known as blue-green algae, are oxygenic, photosynthetic prokaryotes. They occur naturally in many fresh, marine and brackish waters worldwide and play an important role in global carbon and nitrogen cycles. In their long history, cyanobacteria have developed structures and mechanisms that enable them to survive and proliferate under different environmental conditions. In the Baltic Sea, the mass development of cyanobacteria is compounded by a high level of eutrophication. The dominant species in the Baltic, the filamentous Aphanizomenon flos-aquae and Nodularia spumigena, can fix dissolved atmospheric N2, as a result of which they can outcompete other phytoplankton organisms. Heterocystous, filamentous cyanobacteria also make a significant contribution to the internal nutrient loading in the Baltic. The blooms of N. spumigena are of particular concern, as this cyanobacterium produces nodularin (NOD, a hepatotoxic peptide. The concentration of the toxin in the sea is regulated mainly by dilution with uncontaminated water, photolysis, sorption to sediments and microbial degradation. The transfer of the toxin in the Baltic trophic chain through zooplankton, mussels, fish and birds has been reported, but biodilution rather than bioconcentration has been observed. Cyanobacterial blooms are thought to pose a serious threat to the ecosystem. Their harmful effects are related to the occurrence of a high biomass, oxygen depletion, a reduction in biodiversity, and the production of toxic metabolites.

  16. Vision-Based Pose Estimation for Robot-Mediated Hand Telerehabilitation

    Directory of Open Access Journals (Sweden)

    Giuseppe Airò Farulla

    2016-02-01

    Full Text Available Vision-based Pose Estimation (VPE represents a non-invasive solution to allow a smooth and natural interaction between a human user and a robotic system, without requiring complex calibration procedures. Moreover, VPE interfaces are gaining momentum as they are highly intuitive, such that they can be used from untrained personnel (e.g., a generic caregiver even in delicate tasks as rehabilitation exercises. In this paper, we present a novel master–slave setup for hand telerehabilitation with an intuitive and simple interface for remote control of a wearable hand exoskeleton, named HX. While performing rehabilitative exercises, the master unit evaluates the 3D position of a human operator’s hand joints in real-time using only a RGB-D camera, and commands remotely the slave exoskeleton. Within the slave unit, the exoskeleton replicates hand movements and an external grip sensor records interaction forces, that are fed back to the operator-therapist, allowing a direct real-time assessment of the rehabilitative task. Experimental data collected with an operator and six volunteers are provided to show the feasibility of the proposed system and its performances. The results demonstrate that, leveraging on our system, the operator was able to directly control volunteers’ hands movements.

  17. Pose and Shape Reconstruction of a Noncooperative Spacecraft Using Camera and Range Measurements

    Directory of Open Access Journals (Sweden)

    Renato Volpe

    2017-01-01

    Full Text Available Recent interest in on-orbit proximity operations has pushed towards the development of autonomous GNC strategies. In this sense, optical navigation enables a wide variety of possibilities as it can provide information not only about the kinematic state but also about the shape of the observed object. Various mission architectures have been either tested in space or studied on Earth. The present study deals with on-orbit relative pose and shape estimation with the use of a monocular camera and a distance sensor. The goal is to develop a filter which estimates an observed satellite’s relative position, velocity, attitude, and angular velocity, along with its shape, with the measurements obtained by a camera and a distance sensor mounted on board a chaser which is on a relative trajectory around the target. The filter’s efficiency is proved with a simulation on a virtual target object. The results of the simulation, even though relevant to a simplified scenario, show that the estimation process is successful and can be considered a promising strategy for a correct and safe docking maneuver.

  18. Solving ill-posed inverse problems using iterative deep neural networks

    Science.gov (United States)

    Adler, Jonas; Öktem, Ozan

    2017-12-01

    We propose a partially learned approach for the solution of ill-posed inverse problems with not necessarily linear forward operators. The method builds on ideas from classical regularisation theory and recent advances in deep learning to perform learning while making use of prior information about the inverse problem encoded in the forward operator, noise model and a regularising functional. The method results in a gradient-like iterative scheme, where the ‘gradient’ component is learned using a convolutional network that includes the gradients of the data discrepancy and regulariser as input in each iteration. We present results of such a partially learned gradient scheme on a non-linear tomographic inversion problem with simulated data from both the Sheep-Logan phantom as well as a head CT. The outcome is compared against filtered backprojection and total variation reconstruction and the proposed method provides a 5.4 dB PSNR improvement over the total variation reconstruction while being significantly faster, giving reconstructions of 512 × 512 pixel images in about 0.4 s using a single graphics processing unit (GPU).

  19. Vision-Based Pose Estimation for Robot-Mediated Hand Telerehabilitation.

    Science.gov (United States)

    Airò Farulla, Giuseppe; Pianu, Daniele; Cempini, Marco; Cortese, Mario; Russo, Ludovico O; Indaco, Marco; Nerino, Roberto; Chimienti, Antonio; Oddo, Calogero M; Vitiello, Nicola

    2016-02-05

    Vision-based Pose Estimation (VPE) represents a non-invasive solution to allow a smooth and natural interaction between a human user and a robotic system, without requiring complex calibration procedures. Moreover, VPE interfaces are gaining momentum as they are highly intuitive, such that they can be used from untrained personnel (e.g., a generic caregiver) even in delicate tasks as rehabilitation exercises. In this paper, we present a novel master-slave setup for hand telerehabilitation with an intuitive and simple interface for remote control of a wearable hand exoskeleton, named HX. While performing rehabilitative exercises, the master unit evaluates the 3D position of a human operator's hand joints in real-time using only a RGB-D camera, and commands remotely the slave exoskeleton. Within the slave unit, the exoskeleton replicates hand movements and an external grip sensor records interaction forces, that are fed back to the operator-therapist, allowing a direct real-time assessment of the rehabilitative task. Experimental data collected with an operator and six volunteers are provided to show the feasibility of the proposed system and its performances. The results demonstrate that, leveraging on our system, the operator was able to directly control volunteers' hands movements.

  20. Surety of the nation`s critical infrastructures: The challenge restructuring poses to the telecommunications sector

    Energy Technology Data Exchange (ETDEWEB)

    Cox, R.; Drennen, T.E.; Gilliom, L.; Harris, D.L.; Kunsman, D.M.; Skroch, M.J.

    1998-04-01

    The telecommunications sector plays a pivotal role in the system of increasingly connected and interdependent networks that make up national infrastructure. An assessment of the probable structure and function of the bit-moving industry in the twenty-first century must include issues associated with the surety of telecommunications. The term surety, as used here, means confidence in the acceptable behavior of a system in both intended and unintended circumstances. This paper outlines various engineering approaches to surety in systems, generally, and in the telecommunications infrastructure, specifically. It uses the experience and expectations of the telecommunications system of the US as an example of the global challenges. The paper examines the principal factors underlying the change to more distributed systems in this sector, assesses surety issues associated with these changes, and suggests several possible strategies for mitigation. It also studies the ramifications of what could happen if this sector became a target for those seeking to compromise a nation`s security and economic well being. Experts in this area generally agree that the U. S. telecommunications sector will eventually respond in a way that meets market demands for surety. Questions remain open, however, about confidence in the telecommunications sector and the nation`s infrastructure during unintended circumstances--such as those posed by information warfare or by cascading software failures. Resolution of these questions is complicated by the lack of clear accountability of the private and the public sectors for the surety of telecommunications.

  1. The Spatial and the Visual in Mental Spatial Reasoning: An Ill-Posed Distinction

    Science.gov (United States)

    Schultheis, Holger; Bertel, Sven; Barkowsky, Thomas; Seifert, Inessa

    It is an ongoing and controversial debate in cognitive science which aspects of knowledge humans process visually and which ones they process spatially. Similarly, artificial intelligence (AI) and cognitive science research, in building computational cognitive systems, tended to use strictly spatial or strictly visual representations. The resulting systems, however, were suboptimal both with respect to computational efficiency and cognitive plau sibility. In this paper, we propose that the problems in both research strands stem from a mis conception of the visual and the spatial in mental spatial knowl edge pro cessing. Instead of viewing the visual and the spatial as two clearly separable categories, they should be conceptualized as the extremes of a con tinuous dimension of representation. Regarding psychology, a continuous di mension avoids the need to exclusively assign processes and representations to either one of the cate gories and, thus, facilitates a more unambiguous rating of processes and rep resentations. Regarding AI and cognitive science, the con cept of a continuous spatial / visual dimension provides the possibility of rep re sentation structures which can vary continuously along the spatial / visual di mension. As a first step in exploiting these potential advantages of the pro posed conception we (a) introduce criteria allowing for a non-dichotomic judgment of processes and representations and (b) present an approach towards rep re sentation structures that can flexibly vary along the spatial / visual dimension.

  2. Sparse deconvolution for the large-scale ill-posed inverse problem of impact force reconstruction

    Science.gov (United States)

    Qiao, Baijie; Zhang, Xingwu; Gao, Jiawei; Liu, Ruonan; Chen, Xuefeng

    2017-01-01

    Most previous regularization methods for solving the inverse problem of force reconstruction are to minimize the l2-norm of the desired force. However, these traditional regularization methods such as Tikhonov regularization and truncated singular value decomposition, commonly fail to solve the large-scale ill-posed inverse problem in moderate computational cost. In this paper, taking into account the sparse characteristic of impact force, the idea of sparse deconvolution is first introduced to the field of impact force reconstruction and a general sparse deconvolution model of impact force is constructed. Second, a novel impact force reconstruction method based on the primal-dual interior point method (PDIPM) is proposed to solve such a large-scale sparse deconvolution model, where minimizing the l2-norm is replaced by minimizing the l1-norm. Meanwhile, the preconditioned conjugate gradient algorithm is used to compute the search direction of PDIPM with high computational efficiency. Finally, two experiments including the small-scale or medium-scale single impact force reconstruction and the relatively large-scale consecutive impact force reconstruction are conducted on a composite wind turbine blade and a shell structure to illustrate the advantage of PDIPM. Compared with Tikhonov regularization, PDIPM is more efficient, accurate and robust whether in the single impact force reconstruction or in the consecutive impact force reconstruction.

  3. Potential Health Risks Posed by Plant-Derived Cumulative Neurotoxic Bufadienolides in South Africa

    Directory of Open Access Journals (Sweden)

    Christo Botha

    2016-03-01

    Full Text Available Bufadienolide-type cardiac glycosides have a worldwide distribution and are mainly synthesized by plants, but there are also animal sources. In South Africa, members of three genera of the Crassulaceae (Cotyledon, Tylecodon and Kalanchoe cause a unique chronic form of cardiac glycoside poisoning, predominantly in small stock. This paretic/paralytic condition is referred to as “krimpsiekte”, cotyledonosis or “nenta”. “Krimpsiekte” is a plant poisoning only reported from South Africa and is regarded as the most important plant poisoning of small stock in the semi-arid Little Karoo and southern fringes of the Great Karoo. The toxicosis is caused by cumulative bufadienolides which have neurotoxic properties. Four types of cumulative neurotoxic bufadienolides, namely cotyledoside, and the tyledosides, orbicusides and lanceotoxins, have been isolated. Based on the structure activity relationships and certain toxicokinetic parameters possible reasons for their accumulation are presented. Consumption of edible tissues from animals that have ingested these plants poses a potential risk to humans.

  4. The interconnected and cross-border nature of risks posed by infectious diseases.

    Science.gov (United States)

    Suk, Jonathan E; Van Cangh, Thomas; Beauté, Julien; Bartels, Cornelius; Tsolova, Svetla; Pharris, Anastasia; Ciotti, Massimo; Semenza, Jan C

    2014-12-01

    Infectious diseases can constitute public health emergencies of international concern when a pathogen arises, acquires new characteristics, or is deliberately released, leading to the potential for loss of human lives as well as societal disruption. A wide range of risk drivers are now known to lead to and/or exacerbate the emergence and spread of infectious disease, including global trade and travel, the overuse of antibiotics, intensive agriculture, climate change, high population densities, and inadequate infrastructures, such as water treatment facilities. Where multiple risk drivers interact, the potential impact of a disease outbreak is amplified. The varying temporal and geographic frequency with which infectious disease events occur adds yet another layer of complexity to the issue. Mitigating the emergence and spread of infectious disease necessitates mapping and prioritising the interdependencies between public health and other sectors. Conversely, during an international public health emergency, significant disruption occurs not only to healthcare systems but also to a potentially wide range of sectors, including trade, tourism, energy, civil protection, transport, agriculture, and so on. At the same time, dealing with a disease outbreak may require a range of critical sectors for support. There is a need to move beyond narrow models of risk to better account for the interdependencies between health and other sectors so as to be able to better mitigate and respond to the risks posed by emerging infectious disease.

  5. Online absolute pose compensation and steering control of industrial robot based on six degrees of freedom laser measurement

    Science.gov (United States)

    Yang, Juqing; Wang, Dayong; Fan, Baixing; Dong, Dengfeng; Zhou, Weihu

    2017-03-01

    In-situ intelligent manufacturing for large-volume equipment requires industrial robots with absolute high-accuracy positioning and orientation steering control. Conventional robots mainly employ an offline calibration technology to identify and compensate key robotic parameters. However, the dynamic and static parameters of a robot change nonlinearly. It is not possible to acquire a robot's actual parameters and control the absolute pose of the robot with a high accuracy within a large workspace by offline calibration in real-time. This study proposes a real-time online absolute pose steering control method for an industrial robot based on six degrees of freedom laser tracking measurement, which adopts comprehensive compensation and correction of differential movement variables. First, the pose steering control system and robot kinematics error model are constructed, and then the pose error compensation mechanism and algorithm are introduced in detail. By accurately achieving the position and orientation of the robot end-tool, mapping the computed Jacobian matrix of the joint variable and correcting the joint variable, the real-time online absolute pose compensation for an industrial robot is accurately implemented in simulations and experimental tests. The average positioning error is 0.048 mm and orientation accuracy is better than 0.01 deg. The results demonstrate that the proposed method is feasible, and the online absolute accuracy of a robot is sufficiently enhanced.

  6. Tracking a Driver’s Face against Extreme Head Poses and Inference of Drowsiness Using a Hidden Markov Model

    Directory of Open Access Journals (Sweden)

    In-Ho Choi

    2016-05-01

    Full Text Available This study presents a new method to track driver’s facial states, such as head pose and eye-blinking in the real-time basis. Since a driver in the natural driving condition moves his head in diverse ways and his face is often occluded by his hand or the wheel, it should be a great challenge for the standard face models. Among many, Active Appearance Model (AAM, and Active Shape Model (ASM are two favored face models. We have extended Discriminative Bayesian ASM by incorporating the extreme pose cases, called it Pose Extended—Active Shape model (PE-ASM. Two face databases (DB are used for the comparison purpose: one is the Boston University face DB and the other is our custom-made driving DB. Our evaluation indicates that PE-ASM outperforms ASM and AAM in terms of the face fitting against extreme poses. Using this model, we can estimate the driver’s head pose, as well as eye-blinking, by adding respective processes. Two HMMs are trained to model temporal behaviors of these two facial features, and consequently the system can make inference by enumerating these HMM states whether the driver is drowsy or not. Result suggests that it can be used as a driver drowsiness detector in the commercial car where the visual conditions are very diverse and often tough to deal with.

  7. Risk posed to honeybees (Apis mellifera L, Hymenoptera) by an imidacloprid seed dressing of sunflowers.

    Science.gov (United States)

    Schmuck, R; Schöning, R; Stork, A; Schramel, O

    2001-03-01

    In a greenhouse metabolism study, sunflowers were seed-treated with radiolabelled imidacloprid in a 700 g kg-1 WS formulation (Gaucho WS 70) at 0.7 mg AI per seed, and the nature of the resulting residues in nectar and pollen was determined. Only the parent compound and no metabolites were detected in nectar and pollen of these seed-treated sunflower plants (limit of detection laboratory tests, imidacloprid showed high oral toxicity to honeybees (Apis mellifera), with LD50 values between 3.7 and 40.9 ng per bee, corresponding to a lethal food concentration between 0.14 and 1.57 mg kg-1. The residue level of imidacloprid in nectar and pollen of seed-treated sunflower plants in the field was negligible. Under field-growing conditions no residues were detected (limit of detection: 0.0015 mg kg-1) in either nectar or pollen. There were also no detectable residues in nectar and pollen of sunflowers planted as a succeeding crop in soils which previously had been cropped with imidacloprid seed-treated plants. Chronic feeding experiments with sunflower honey fortified with 0.002, 0.005, 0.010 and 0.020 mg kg-1 imidacloprid were conducted to assess potential long-term adverse effects on honeybee colonies. Testing end-points in this 39-day feeding study were mortality, feeding activity, wax/comb production, breeding performance and colony vitality. Even at the highest test concentration, imidacloprid showed no adverse effects on the development of the exposed bee colonies. This no-adverse-effect concentration of 0.020 mg kg-1 compares with a field residue level of less than 0.0015 mg kg-1 (= limit of detection in the field residue studies) which clearly shows that a sunflower seed dressing with imidacloprid poses no risk to honeybees. This conclusion is confirmed by observations made in more than 10 field studies and several tunnel tests.

  8. Do shade-grown coffee plantations pose a disease risk for wild birds?

    Science.gov (United States)

    Hernandez, Sonia M; Peters, Valerie E; Weygandt, P Logan; Jimenez, Carlos; Villegas, Pedro; O'Connor, Barry; Yabsley, Michael J; Garcia, Maricarmen; Riblet, Sylva M; Carroll, C Ron

    2013-06-01

    Shade-grown coffee plantations are often promoted as a conservation strategy for wild birds. However, these agro-ecosystems are actively managed for food production, which may alter bird behaviors or interactions that could change bird health, compared to natural forest. To examine whether there is a difference between the health parameters of wild birds inhabiting shade-grown coffee plantations and natural forest, we evaluated birds in Costa Rica for (1) their general body condition, (2) antibodies to pathogens, (paramyxovirus and Mycoplasma spp.), and (3) the prevalence and diversity of endo-, ecto-, and hemoparasites. We measured exposure to Mycoplasma spp. and paramyxovirus because these are pathogens that could have been introduced with domestic poultry, one mechanism by which these landscapes could be detrimental to wild birds. We captured 1,561 birds representing 75 species. Although seasonal factors influenced body condition, we did not find bird general body condition to be different. A total of 556 birds of 31 species were tested for antibodies against paramyxovirus-1. Of these, five birds tested positive, four of which were from shade coffee. Out of 461 other tests for pathogens (for antibodies and nucleotide detection), none were positive. Pterolichus obtusus, the feather mite of chickens, was found on 15 birds representing two species and all were from shade-coffee plantations. Larvated eggs of Syngamus trachea, a nematode typically associated with chickens, were found in four birds captured in shade coffee and one captured in forest. For hemoparasites, a total of 1,121 blood smears from 68 bird species were examined, and only one species showed a higher prevalence of infection in shade coffee. Our results indicate that shade-coffee plantations do not pose a significant health risk to forest birds, but at least two groups of pathogens may deserve further attention: Haemoproteus spp. and the diversity and identity of endoparasites.

  9. Estimation of the environmental risk posed by landfills using chemical, microbiological and ecotoxicological testing of leachates.

    Science.gov (United States)

    Matejczyk, Marek; Płaza, Grażyna A; Nałęcz-Jawecki, Grzegorz; Ulfig, Krzysztof; Markowska-Szczupak, Agata

    2011-02-01

    parameters of the landfill leachates should be analyzed together to assess the environmental risk posed by landfill emissions. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Risks posed by climate change to the delivery of Water Framework Directive objectives in the UK.

    Science.gov (United States)

    Wilby, R L; Orr, H G; Hedger, M; Forrow, D; Blackmore, M

    2006-12-01

    The EU Water Framework Directive (WFD) is novel because it integrates water quality, water resources, physical habitat and, to some extent, flooding for all surface and groundwaters and takes forward river basin management. However, the WFD does not explicitly mention risks posed by climate change to the achievement of its environmental objectives. This is despite the fact that the time scale for the implementation process and achieving particular objectives extends into the 2020s, when climate models project changes in average temperature and precipitation. This paper begins by reviewing the latest UK climate change scenarios and the wider policy and science context of the WFD. We then examine the potential risks of climate change to key phases of the River Basin Management Process that underpin the WFD (such as characterisation of river basins and their water bodies, risk assessments to identify pressures and impacts, programmes of measures (POMs) options appraisal, monitoring and modelling, policy and management activities). Despite these risks the WFD could link new policy and participative mechanisms (being established for the River Basin Management Plans) to the emerging framework of national and regional climate change adaptation policy. The risks are identified with a view to informing policy opportunities, objective setting, adaptation strategies and the research agenda. Key knowledge gaps have already been identified during the implementation of the WFD, such as the links between hydromorphology and ecosystem status, but the overarching importance of linking climate change to these considerations needs to be highlighted. The next generation of (probabilistic) climate change scenarios will present new opportunities and challenges for risk analysis and policy-making.

  11. Export of commercial Hass avocados from Argentina poses negligible risk of Ceratitis capitata (Diptera: Tephritidae) infestation.

    Science.gov (United States)

    Villagrán, M Elvira; Willink, Eduardo; Vera, M Teresa; Follett, Peter

    2012-08-01

    Argentina has to meet quarantine restrictions because of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), to export 'Hass' avocados, Persea americana Miller, to certain countries. Hass avocado at the hard, mature green stage is potentially a conditional nonhost for C. capitata and could open export markets without the need for a quarantine treatment. Trapping data from 1998 to 2006 showed that C. capitata was present in avocado orchards, particularly early in the harvest season. The host status of hard, mature green Hass avocado to C. capitata was evaluated using laboratory and field cage tests under no-choice conditions and by assessing natural levels of infestation in commercially harvested fruit from the main avocado production area. In total, 2,250 hard, mature green avocado fruit were exposed to 11,250 gravid females for 24 or 48 h after harvest in laboratory or field cages, and no infestations were found. During 11 seasons, 5,949 fruit in total were sampled from the trees and 992 fruit were collected from the ground, and in none of them were any live or dead fruit fly larvae found. Inspection of >198,000 commercial fruit at the packinghouse from 1998 to 2011 showed no symptoms of fruit fly infestation. These data exceed the published standards for determination of nonhost status, as well as the Probit 9 standard for development of quarantine treatments. Hass avocado harvested at the hard, mature green stage was not infested by C. capitata and seems to pose a negligible quarantine risk. As a consequence, no postharvest treatment or other quarantine actions should be required by importing countries.

  12. Direct ultrasound to video registration using photoacoustic markers from a single image pose

    Science.gov (United States)

    Cheng, Alexis; Guo, Xiaoyu; Kang, Hyun Jae; Choti, Michael A.; Kang, Jin U.; Taylor, Russell H.; Boctor, Emad M.

    2015-03-01

    Fusion of video and other imaging modalities is common in modern surgical scenarios to provide surgeons with additional information. Doing so requires the use of interventional guidance equipment and surgical navigation systems to register the tools and devices used in surgery with each other. In this work, we focus explicitly on registering ultrasound with a stereocamera system using photoacoustic markers. Previous work has shown that photoacoustic markers can be used to register three-dimensional ultrasound with video resulting in target registration errors lower than the current available systems. Photoacoustic markers are non-collinear laser spots projected onto some surface. They can be simultaneously visualized by a stereocamera system and in an ultra-sound volume because of the photoacoustic effect. This work replaces the three-dimensional ultrasound volume with images from a single ultrasound image pose. While an ultrasound volume provides more information than an ultrasound image, it has its disadvantages such as higher cost and slower acquisition rate. However, in general, it is difficult to register two-dimensional with three-dimensional spatial data. We propose the use of photoacoustic markers viewed by a convex array ultrasound transducer. Each photoacoustic markers wavefront provides information on its elevational position, resulting in three-dimensional spatial data. This development enhances this methods practicality as convex array transducers are more common in surgical practice than three-dimensional transducers. This work is demonstrated on a synthetic phantom. The resulting target registration error for this experiment was 2.47mm and the standard deviations was 1.29mm, which is comparable to current available systems.

  13. Tibio-femoral joint constraints for bone pose estimation during movement using multi-body optimization.

    Science.gov (United States)

    Bergamini, E; Pillet, H; Hausselle, J; Thoreux, P; Guerard, S; Camomilla, V; Cappozzo, A; Skalli, W

    2011-04-01

    When using skin markers and stereophotogrammetry for movement analysis, bone pose estimation may be performed using multi-body optimization with the intent of reducing the effect of soft tissue artefacts. When the joint of interest is the knee, improvement of this approach requires defining subject-specific relevant kinematic constraints. The aim of this work was to provide these constraints in the form of plausible values for the distances between origin and insertion of the main ligaments (ligament lengths), during loaded healthy knee flexion, taking into account the indeterminacies associated with landmark identification during anatomical calibration. Ligament attachment sites were identified through virtual palpation on digital bone templates. Attachments sites were estimated for six knee specimens by matching the femur and tibia templates to low-dose stereoradiography images. Movement data were obtained using stereophotogrammetry and pin markers. Relevant ligament lengths for the anterior and posterior cruciate, lateral collateral, and deep and superficial bundles of the medial collateral ligaments (ACL, PCL, LCL, MCLdeep, MCLsup) were calculated. The effect of landmark identification variability was evaluated performing a Monte Carlo simulation on the coordinates of the origin-insertion centroids. The ACL and LCL lengths were found to decrease, and the MCLdeep length to increase significantly during flexion, while variations in PCL and MCLsup length was concealed by the experimental indeterminacy. An analytical model is given that provides subject-specific plausible ligament length variations as functions of the knee flexion angle and that can be incorporated in a multi-body optimization procedure. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Stereovision-based pose and inertia estimation of unknown and uncooperative space objects

    Science.gov (United States)

    Pesce, Vincenzo; Lavagna, Michèle; Bevilacqua, Riccardo

    2017-01-01

    Autonomous close proximity operations are an arduous and attractive problem in space mission design. In particular, the estimation of pose, motion and inertia properties of an uncooperative object is a challenging task because of the lack of available a priori information. This paper develops a novel method to estimate the relative position, velocity, angular velocity, attitude and the ratios of the components of the inertia matrix of an uncooperative space object using only stereo-vision measurements. The classical Extended Kalman Filter (EKF) and an Iterated Extended Kalman Filter (IEKF) are used and compared for the estimation procedure. In addition, in order to compute the inertia properties, the ratios of the inertia components are added to the state and a pseudo-measurement equation is considered in the observation model. The relative simplicity of the proposed algorithm could be suitable for an online implementation for real applications. The developed algorithm is validated by numerical simulations in MATLAB using different initial conditions and uncertainty levels. The goal of the simulations is to verify the accuracy and robustness of the proposed estimation algorithm. The obtained results show satisfactory convergence of estimation errors for all the considered quantities. The obtained results, in several simulations, shows some improvements with respect to similar works, which deal with the same problem, present in literature. In addition, a video processing procedure is presented to reconstruct the geometrical properties of a body using cameras. This inertia reconstruction algorithm has been experimentally validated at the ADAMUS (ADvanced Autonomous MUltiple Spacecraft) Lab at the University of Florida. In the future, this different method could be integrated to the inertia ratios estimator to have a complete tool for mass properties recognition.

  15. Penalized linear regression for discrete ill-posed problems: A hybrid least-squares and mean-squared error approach

    KAUST Repository

    Suliman, Mohamed Abdalla Elhag

    2016-12-19

    This paper proposes a new approach to find the regularization parameter for linear least-squares discrete ill-posed problems. In the proposed approach, an artificial perturbation matrix with a bounded norm is forced into the discrete ill-posed model matrix. This perturbation is introduced to enhance the singular-value (SV) structure of the matrix and hence to provide a better solution. The proposed approach is derived to select the regularization parameter in a way that minimizes the mean-squared error (MSE) of the estimator. Numerical results demonstrate that the proposed approach outperforms a set of benchmark methods in most cases when applied to different scenarios of discrete ill-posed problems. Jointly, the proposed approach enjoys the lowest run-time and offers the highest level of robustness amongst all the tested methods.

  16. Binding mode similarity measures for ranking of docking poses: a case study on the adenosine A2A receptor

    Science.gov (United States)

    Anighoro, Andrew; Bajorath, Jürgen

    2016-06-01

    We report an investigation designed to explore alternative approaches for ranking of docking poses in the search for antagonists of the adenosine A2A receptor, an attractive target for structure-based virtual screening. Calculation of 3D similarity of docking poses to crystallographic ligand(s) as well as similarity of receptor-ligand interaction patterns was consistently superior to conventional scoring functions for prioritizing antagonists over decoys. Moreover, the use of crystallographic antagonists and agonists, a core fragment of an antagonist, and a model of an agonist placed into the binding site of an antagonist-bound form of the receptor resulted in a significant early enrichment of antagonists in compound rankings. Taken together, these findings showed that the use of binding modes of agonists and/or antagonists, even if they were only approximate, for similarity assessment of docking poses or comparison of interaction patterns increased the odds of identifying new active compounds over conventional scoring.

  17. Vision-Based Cooperative Pose Estimation for Localization in Multi-Robot Systems Equipped with RGB-D Cameras

    Directory of Open Access Journals (Sweden)

    Xiaoqin Wang

    2014-12-01

    Full Text Available We present a new vision based cooperative pose estimation scheme for systems of mobile robots equipped with RGB-D cameras. We first model a multi-robot system as an edge-weighted graph. Then, based on this model, and by using the real-time color and depth data, the robots with shared field-of-views estimate their relative poses in pairwise. The system does not need the existence of a single common view shared by all robots, and it works in 3D scenes without any specific calibration pattern or landmark. The proposed scheme distributes working loads evenly in the system, hence it is scalable and the computing power of the participating robots is efficiently used. The performance and robustness were analyzed both on synthetic and experimental data in different environments over a range of system configurations with varying number of robots and poses.

  18. 2D-3D feature association via projective transform invariants for model-based 3D pose estimation

    Science.gov (United States)

    Gedik, O. Serdar; Alatan, A. Aydin

    2012-03-01

    The three dimensional (3D) tracking of rigid objects is required in many applications, such as 3D television (3DTV) and augmented reality. Accurate and robust pose estimates enable improved structure reconstructions for 3DTV and reduce jitter in augmented reality scenarios. On the other hand, reliable 2D-3D feature association is one of the most crucial requirements for obtaining high quality 3D pose estimates. In this paper, a 2D-3D registration method, which is based on projective transform invariants, is proposed. Due to the fact that projective transform invariants are highly dependent on 2D and 3D coordinates, the proposed method relies on pose consistencies in order to increase robustness of 2D-3D association. The reliability of the approach is shown by comparisons with RANSAC, perspective factorization and SoftPOSIT based methods on real and artificial data.

  19. Prediction of binding poses to FXR using multi-targeted docking combined with molecular dynamics and enhanced sampling

    Science.gov (United States)

    Bhakat, Soumendranath; Åberg, Emil; Söderhjelm, Pär

    2017-10-01

    Advanced molecular docking methods often aim at capturing the flexibility of the protein upon binding to the ligand. In this study, we investigate whether instead a simple rigid docking method can be applied, if combined with multiple target structures to model the backbone flexibility and molecular dynamics simulations to model the sidechain and ligand flexibility. The methods are tested for the binding of 35 ligands to FXR as part of the first stage of the Drug Design Data Resource (D3R) Grand Challenge 2 blind challenge. The results show that the multiple-target docking protocol performs surprisingly well, with correct poses found for 21 of the ligands. MD simulations started on the docked structures are remarkably stable, but show almost no tendency of refining the structure closer to the experimentally found binding pose. Reconnaissance metadynamics enhances the exploration of new binding poses, but additional collective variables involving the protein are needed to exploit the full potential of the method.

  20. A modified quasi-boundary value method for a class of abstract parabolic ill-posed problems

    Directory of Open Access Journals (Sweden)

    Denche M

    2006-01-01

    Full Text Available We study a final value problem for first-order abstract differential equation with positive self-adjoint unbounded operator coefficient. This problem is ill-posed. Perturbing the final condition, we obtain an approximate nonlocal problem depending on a small parameter. We show that the approximate problems are well posed and that their solutions converge if and only if the original problem has a classical solution. We also obtain estimates of the solutions of the approximate problems and a convergence result of these solutions. Finally, we give explicit convergence rates.

  1. A modified quasi-boundary value method for a class of abstract parabolic ill-posed problems

    Directory of Open Access Journals (Sweden)

    S. Djezzar

    2006-02-01

    Full Text Available We study a final value problem for first-order abstract differential equation with positive self-adjoint unbounded operator coefficient. This problem is ill-posed. Perturbing the final condition, we obtain an approximate nonlocal problem depending on a small parameter. We show that the approximate problems are well posed and that their solutions converge if and only if the original problem has a classical solution. We also obtain estimates of the solutions of the approximate problems and a convergence result of these solutions. Finally, we give explicit convergence rates.

  2. Invasion risks posed by ornamental freshwater fish trade to southeastern Brazilian rivers

    Directory of Open Access Journals (Sweden)

    Andre Lincoln Barroso de Magalhaes

    , P. reticulata, and Amatitlania nigrofasciata can potentially invade the Todos os Santos River. Six recommendations are suggested to reduce the invasion risk of non-native fish on the rivers surveyed posed by aquarium trade.

  3. Experimental Constraints on the Respiratory Health Hazard Posed by Crystalline Silica-bearing Volcanic Ash

    Science.gov (United States)

    Damby, D. E.; Horwell, C. J.; Baxter, P. J.

    2016-12-01

    Since volcanic ash from the 1980 eruption of Mount St Helens, USA, impacted on a million inhabitants in the Pacific Northwest, it is known that a substantial fraction of volcanic ejecta is respirable and therefore capable of being a human health hazard. Exacerbation of airway problems, such as asthma and chronic bronchitis, due to an increase in ambient particulate matter following the eruption, was an expected finding; however, a significant amount of cristobalite, a toxic mineral, in the ash was unforeseen and led to repeated toxicological testing of the ash to establish the hazard posed to human health. Those results together with studies on cristobalite-bearing ash from other major eruptions suggest that volcanic cristobalite is minimally reactive relative to pure phase standards. This finding adheres to a well-established thesis on the variable pathogenicity of crystalline silica, whereby intrinsic characteristics and extrinsic modifications of the crystalline silica govern reactivity. Indeed, chemical impurities (up to 4 wt% aluminum) and substantial structural defects have been implicated in the reduced potency of volcanic cristobalite. However, whilst not overtly toxic, volcanic ash exposure can initiate a sample-dependent inflammatory response in macrophages, a cell type that provides a first line of defense against inhaled particles. Inflammation plays a pivotal role in crystal-driven disease progression and can be observed in patients with particle-induced lung disease. We demonstrate that ash can induce inflammation by stimulating the NLRP3 inflammasome, a cytosolic receptor complex that drives the inflammatory response to several endo- and exogenous crystalline materials. The impact of inflammasome activation mediated by inhaled ash particles and its potential relevance in chronic pulmonary diseases was confirmed in primary human cells; however, it is not yet known whether the response resolves in vivo. The NLRP3 inflammasome as an ash

  4. The Numerical Inversion of the Laplace Transform in Reproducing Kernel Hilbert Spaces for Ill-Posed Problems

    Science.gov (United States)

    Iqbal, M.

    2002-01-01

    In this paper we have converted the Laplace transform into an integral equation of the first kind of convolution type, which is an ill-posed problem, and used a statistical regularization method to solve it. The method is applied to three examples. It gives a good approximation to the true solution and compares well with the method given by…

  5. Conceiving Human Interaction by Visualising Depth Data of Head Pose Changes and Emotion Recognition via Facial Expressions

    NARCIS (Netherlands)

    Kalliatakis, Grigorios; Stergiou, A.G.; Vidakis, Nikolaos

    2017-01-01

    Affective computing in general and human activity and intention analysis in particular comprise a rapidly-growing field of research. Head pose and emotion changes present serious challenges when applied to player’s training and ludology experience in serious games, or analysis of customer

  6. Baseline Face Detection, Head Pose Estimation, and Coarse Direction Detection for Facial Data in the SHRP2 Naturalistic Driving Study

    Energy Technology Data Exchange (ETDEWEB)

    Paone, Jeffrey R [ORNL; Bolme, David S [ORNL; Ferrell, Regina Kay [ORNL; Aykac, Deniz [ORNL; Karnowski, Thomas Paul [ORNL

    2015-01-01

    Keeping a driver focused on the road is one of the most critical steps in insuring the safe operation of a vehicle. The Strategic Highway Research Program 2 (SHRP2) has over 3,100 recorded videos of volunteer drivers during a period of 2 years. This extensive naturalistic driving study (NDS) contains over one million hours of video and associated data that could aid safety researchers in understanding where the driver s attention is focused. Manual analysis of this data is infeasible, therefore efforts are underway to develop automated feature extraction algorithms to process and characterize the data. The real-world nature, volume, and acquisition conditions are unmatched in the transportation community, but there are also challenges because the data has relatively low resolution, high compression rates, and differing illumination conditions. A smaller dataset, the head pose validation study, is available which used the same recording equipment as SHRP2 but is more easily accessible with less privacy constraints. In this work we report initial head pose accuracy using commercial and open source face pose estimation algorithms on the head pose validation data set.

  7. A randomized controlled study of power posing before public speaking exposure for social anxiety disorder: No evidence for augmentative effects

    NARCIS (Netherlands)

    Davis, M.L.; Papini, S.; Rosenfield, D.; Roelofs, K.; Kolb, S.; Powers, M.B.; Smits, J.A.J.

    2017-01-01

    This manuscript details a randomized controlled study designed to test the efficacy of power posing (i.e., briefly holding postures associated with dominance and power) as an augmentative strategy for exposure therapy for social anxiety disorder (SAD). Seventy-three individuals diagnosed with SAD

  8. Own- and Other-Race Face Identity Recognition in Children: The Effects of Pose and Feature Composition

    Science.gov (United States)

    Anzures, Gizelle; Kelly, David J.; Pascalis, Olivier; Quinn, Paul C.; Slater, Alan M.; de Viviés, Xavier; Lee, Kang

    2014-01-01

    We used a matching-to-sample task and manipulated facial pose and feature composition to examine the other-race effect (ORE) in face identity recognition between 5 and 10 years of age. Overall, the present findings provide a genuine measure of own- and other-race face identity recognition in children that is independent of photographic and image…

  9. Examining Interactions between Problem Posing and Problem Solving with Prospective Primary Teachers: A Case of Using Fractions

    Science.gov (United States)

    Xie, Jinxia; Masingila, Joanna O.

    2017-01-01

    Existing studies have quantitatively evidenced the relatedness between problem posing and problem solving, as well as the magnitude of this relationship. However, the nature and features of this relationship need further qualitative exploration. This paper focuses on exploring the interactions, i.e., mutual effects and supports, between problem…

  10. A cost–benefit analysis of mitigation options for optimal management of risks posed by flow-like phenomena

    DEFF Research Database (Denmark)

    Narasimhan, Harikrishna; Ferlisi, Settimio; Cascini, Leonardo

    2016-01-01

    for reducing the risks posed by different rainfall-induced flow-like phenomena—which include hyperconcentrated flows, debris flows and landslides on open slopes—in the municipality of Nocera Inferiore (located in the Campania region in southern Italy) is then described. As demonstrated through the case study...

  11. Stochastic Well-posed Systems and Well-posedness of Some Stochastic Partial Differential Equations with Boundary Control and Observation

    OpenAIRE

    LU, Qi

    2015-01-01

    We generalize the concept "well-posed linear system" to stochastic linear control systems and study some basic properties of such kind systems. Under our generalized definition, we show the well-posedness of the stochastic heat equation and the stochastic Schr\\"odinger equation with suitable boundary control and observation operators, respectively.

  12. Voxel-based registration of simulated and real patient CBCT data for accurate dental implant pose estimation

    Science.gov (United States)

    Moreira, António H. J.; Queirós, Sandro; Morais, Pedro; Rodrigues, Nuno F.; Correia, André Ricardo; Fernandes, Valter; Pinho, A. C. M.; Fonseca, Jaime C.; Vilaça, João. L.

    2015-03-01

    The success of dental implant-supported prosthesis is directly linked to the accuracy obtained during implant's pose estimation (position and orientation). Although traditional impression techniques and recent digital acquisition methods are acceptably accurate, a simultaneously fast, accurate and operator-independent methodology is still lacking. Hereto, an image-based framework is proposed to estimate the patient-specific implant's pose using cone-beam computed tomography (CBCT) and prior knowledge of implanted model. The pose estimation is accomplished in a threestep approach: (1) a region-of-interest is extracted from the CBCT data using 2 operator-defined points at the implant's main axis; (2) a simulated CBCT volume of the known implanted model is generated through Feldkamp-Davis-Kress reconstruction and coarsely aligned to the defined axis; and (3) a voxel-based rigid registration is performed to optimally align both patient and simulated CBCT data, extracting the implant's pose from the optimal transformation. Three experiments were performed to evaluate the framework: (1) an in silico study using 48 implants distributed through 12 tridimensional synthetic mandibular models; (2) an in vitro study using an artificial mandible with 2 dental implants acquired with an i-CAT system; and (3) two clinical case studies. The results shown positional errors of 67+/-34μm and 108μm, and angular misfits of 0.15+/-0.08° and 1.4°, for experiment 1 and 2, respectively. Moreover, in experiment 3, visual assessment of clinical data results shown a coherent alignment of the reference implant. Overall, a novel image-based framework for implants' pose estimation from CBCT data was proposed, showing accurate results in agreement with dental prosthesis modelling requirements.

  13. Challenges that Preventive Conservation poses to the Cultural Heritage documentation field

    Science.gov (United States)

    Van Balen, K.

    2017-08-01

    This contribution examines the challenges posed to the cultural heritage documentation community (the CIPA community and others) in implementing a preventive conservation approach of the built heritage in today's society. The "DNA" of Preventive Conservation. Various authors so far support the argument that preventive conservation is an effective way to respond to the challenges society faces with the preservation of its Cultural Heritage (Van Balen, 2013). A few decades of experiences with the application of preventive conservation in the field of immovable heritage in the form of Monumentenwacht in The Netherland and in Flanders have shown that a good monitoring of the state of preservation with a strong push for maintenance activities contributes to more preservation of authenticity, to more cost-effective preservation and to empowering society in dealing with heritage preservation. (Cebron, 2008) An analysis of these and similar experiences demonstrates that these "Monumentenwacht" activities represent only a part of what could be named a preventive conservation system. Other fields in which prevention is advocated for its higher efficiency, show the importance of system thinking in the development of improved strategies. Applying this approach to the field of the immovable heritage, referring to the initial results shown by the Monumentenwacht practices, it becomes clear that different dimension are at stake simultaneously: the preservation of authenticity or integrity, the management of resources and the connection with society. It shows that the analysis of challenges in heritage preservation and the development of strategies is à priori multifaceted and therefor has a certain level of complexity. The sustainability of the preservation of cultural heritage buildings and sites can be measured according to its multiple economic, social, environmental and cultural support. The Cultural Heritage Counts for Europe report shows that the more diverse the support

  14. Challenges that Preventive Conservation poses to the Cultural Heritage documentation field

    Directory of Open Access Journals (Sweden)

    K. Van Balen

    2017-08-01

    Full Text Available This contribution examines the challenges posed to the cultural heritage documentation community (the CIPA community and others in implementing a preventive conservation approach of the built heritage in today’s society. The “DNA” of Preventive Conservation. Various authors so far support the argument that preventive conservation is an effective way to respond to the challenges society faces with the preservation of its Cultural Heritage (Van Balen, 2013. A few decades of experiences with the application of preventive conservation in the field of immovable heritage in the form of Monumentenwacht in The Netherland and in Flanders have shown that a good monitoring of the state of preservation with a strong push for maintenance activities contributes to more preservation of authenticity, to more cost-effective preservation and to empowering society in dealing with heritage preservation. (Cebron, 2008 An analysis of these and similar experiences demonstrates that these “Monumentenwacht” activities represent only a part of what could be named a preventive conservation system. Other fields in which prevention is advocated for its higher efficiency, show the importance of system thinking in the development of improved strategies. Applying this approach to the field of the immovable heritage, referring to the initial results shown by the Monumentenwacht practices, it becomes clear that different dimension are at stake simultaneously: the preservation of authenticity or integrity, the management of resources and the connection with society. It shows that the analysis of challenges in heritage preservation and the development of strategies is à priori multifaceted and therefor has a certain level of complexity. The sustainability of the preservation of cultural heritage buildings and sites can be measured according to its multiple economic, social, environmental and cultural support. The Cultural Heritage Counts for Europe report shows that the

  15. Invasion risks posed by ornamental freshwater fish trade to southeastern Brazilian rivers

    Directory of Open Access Journals (Sweden)

    André Lincoln Barroso de Magalhães

    , P. reticulata, and Amatitlania nigrofasciata can potentially invade the Todos os Santos River. Six recommendations are suggested to reduce the invasion risk of non-native fish on the rivers surveyed posed by aquarium trade.Um modelo foi desenvolvido para avaliar o risco de invasão de peixes ornamentais não-nativos em seis rios do estado de Minas Gerais, sudeste do Brasil, com foco na popularidade das espécies. Trinta e nove lojas de aquário em seis cidades foram visitadas mensalmente de janeiro a dezembro de 2007. Em cada cidade, as espécies foram identificadas e suas biologias e histórias de invasão foram obtidas da literatura. Calculou-se a frequência de ocorrência anual e quantidade média mensal de exemplares disponíveis nas lojas. Foram obtidas temperaturas trimestrais da água e dados de oxigênio dissolvido de 1997 a 2007 dos rios Velhas, Muriaé, Uberabinha, Sapucaí-Mirim, Doce e Todos os Santos a partir de bases de dados públicas. O risco de invasão de cada espécie foi avaliado através de um modelo composto por nove parâmetros agrupados em quatro variáveis: (i Invasividade (limite de alcance térmico/oxigênio dissolvido, dieta, cuidado parental ou fecundidade, (ii Histórico de invasões (estabelecimento, (iii Pressão de propágulos (sucesso comercial, composto pela frequência de ocorrência anual e número de exemplares disponíveis mensalmente nas lojas, e (iv Invasibilidade (temperatura da água/oxigênio dissolvido dos rios compatível com o limite de alcance térmico/ oxigênio dissolvido das espécies. Das 345 espécies de peixes ornamentais para venda, 332 são não-nativos para Minas Gerais (n = 151 ou Brasil (n = 194. Com base nos valores de corte propostos, cinco espécies de peixes ornamentais não-nativos (Cyprinus rubrofuscus, Carassius auratus, Xiphophorus hellerii, Poecilia reticulata e P. latipinna podem potencialmente invadir os rios Velhas e Muriaé, quatro espécies (C. rubrofuscus, C. auratus, X. helleri, P

  16. Challenges that Preventive Conservation poses to the Cultural Heritage documentation field

    Science.gov (United States)

    Van Balen, K.

    2017-08-01

    This contribution examines the challenges posed to the cultural heritage documentation community (the CIPA community and others) in implementing a preventive conservation approach of the built heritage in today's society. The "DNA" of Preventive Conservation. Various authors so far support the argument that preventive conservation is an effective way to respond to the challenges society faces with the preservation of its Cultural Heritage (Van Balen, 2013). A few decades of experiences with the application of preventive conservation in the field of immovable heritage in the form of Monumentenwacht in The Netherland and in Flanders have shown that a good monitoring of the state of preservation with a strong push for maintenance activities contributes to more preservation of authenticity, to more cost-effective preservation and to empowering society in dealing with heritage preservation. (Cebron, 2008) An analysis of these and similar experiences demonstrates that these "Monumentenwacht" activities represent only a part of what could be named a preventive conservation system. Other fields in which prevention is advocated for its higher efficiency, show the importance of system thinking in the development of improved strategies. Applying this approach to the field of the immovable heritage, referring to the initial results shown by the Monumentenwacht practices, it becomes clear that different dimension are at stake simultaneously: the preservation of authenticity or integrity, the management of resources and the connection with society. It shows that the analysis of challenges in heritage preservation and the development of strategies is à priori multifaceted and therefor has a certain level of complexity. The sustainability of the preservation of cultural heritage buildings and sites can be measured according to its multiple economic, social, environmental and cultural support. The Cultural Heritage Counts for Europe report shows that the more diverse the support

  17. Buckling-driven delamination growth in composite laminates: Guidelines for assessing the threat posed by interlaminar matrix delamination

    DEFF Research Database (Denmark)

    Bhushan, Karihaloo; Stang, Henrik

    2008-01-01

    This paper is concerned with development of a simple procedure to assess the threat posed by interlaminar matrix delaminations to the integrity of composite laminates when they are situated in a compressive stress field. Depending upon the size of the delamination, its location below the surface...... and on the level of the applied stress, it may or may not buckle away from the rest of the laminate. If it buckles, the post-buckling response will depend upon the applied compressive stress level, the thickness of the delaminated ply and the interlaminar critical energy release rate of the composite material...... for the mode mixity present at the delamination front. The pre- and post-buckling response is examined in its simplest form and guidelines provided for assessing whether or not a delamination detected during quality control or inspection poses a threat to the safe operation of the composite laminate....

  18. Adaptive relative pose control for autonomous spacecraft rendezvous and proximity operations with thrust misalignment and model uncertainties

    Science.gov (United States)

    Sun, Liang; Zheng, Zewei

    2017-04-01

    An adaptive relative pose control strategy is proposed for a pursue spacecraft in proximity operations on a tumbling target. Relative position vector between two spacecraft is required to direct towards the docking port of the target while the attitude of them must be synchronized. With considering the thrust misalignment of pursuer, an integrated controller for relative translational and relative rotational dynamics is developed by using norm-wise adaptive estimations. Parametric uncertainties, unknown coupled dynamics, and bounded external disturbances are compensated online by adaptive update laws. It is proved via Lyapunov stability theory that the tracking errors of relative pose converge to zero asymptotically. Numerical simulations including six degrees-of-freedom rigid body dynamics are performed to demonstrate the effectiveness of the proposed controller.

  19. On a level-set method for ill-posed problems with piecewise non-constant coefficients

    OpenAIRE

    Cezaro, Adriano de

    2012-01-01

    We investigate a level-set type method for solving ill-posed problems, with the assumption that the solutions are piecewise, but not necessarily constant functions with unknown level sets and unknown level values. In order to get stable approximate solutions of the inverse problem we propose a Tikhonov-type regularization approach coupled with a level set framework. We prove the existence of generalized minimizers for the Tikhonov functional. Moreover, we prove convergence and stability of th...

  20. Environmental challenges posed by veld fires in fragile regions: The case of the Bulilima and Mangwe districts in southern Zimbabwe

    Directory of Open Access Journals (Sweden)

    Ernest Dube

    2015-02-01

    Full Text Available This original research confronted challenges to environmental management and sustainability posed by veld fires in the Bulilima and Mangwe Districts of Matabeleland in the South Province in southern Zimbabwe. Veld fires have affected the fauna and flora, polluted air and water, and destroyed livelihoods. The study aimed at establishing challenges to environmental sustainability posed by veld fires, identifying the type of environment upon which veld fires have impacted, analysing legal issues and other interventions surrounding the control of veld fires and suggesting new control measures for veld fires. A qualitative research design and quota sampling were used. The study involved 30 participants. Data was collected through a questionnaire, an interview guide and participant observation. Challenges to environmental management and sustainability posed by veld fires include property damage, reduced soil fertility, destruction of vegetation, air and water pollution and destruction of wildlife. Most veld fires are a result of human actions that emanate from the disposal of cigarettes, the burning of vegetation when preparing fields, the use of fire by hunters, smoking out bees and the making of fires by motorists along highways. The government should consider reviewing the current environmental statues. Fireguards should be wide enough to lessen veld-fire impact. Lastly, veld-fire campaigns and rehearsals should be run on a regular basis. It is hoped that this work would make a significant contribution through improving the current thinking about environmental management and sustainability, thereby benefiting policy makers, practitioners and stakeholders.

  1. Real-time human pose estimation and gesture recognition from depth images using superpixels and SVM classifier.

    Science.gov (United States)

    Kim, Hanguen; Lee, Sangwon; Lee, Dongsung; Choi, Soonmin; Ju, Jinsun; Myung, Hyun

    2015-05-26

    In this paper, we present human pose estimation and gesture recognition algorithms that use only depth information. The proposed methods are designed to be operated with only a CPU (central processing unit), so that the algorithm can be operated on a low-cost platform, such as an embedded board. The human pose estimation method is based on an SVM (support vector machine) and superpixels without prior knowledge of a human body model. In the gesture recognition method, gestures are recognized from the pose information of a human body. To recognize gestures regardless of motion speed, the proposed method utilizes the keyframe extraction method. Gesture recognition is performed by comparing input keyframes with keyframes in registered gestures. The gesture yielding the smallest comparison error is chosen as a recognized gesture. To prevent recognition of gestures when a person performs a gesture that is not registered, we derive the maximum allowable comparison errors by comparing each registered gesture with the other gestures. We evaluated our method using a dataset that we generated. The experiment results show that our method performs fairly well and is applicable in real environments.

  2. Estimation of Full-Body Poses Using Only Five Inertial Sensors: An Eager or Lazy Learning Approach?

    Directory of Open Access Journals (Sweden)

    Frank J. Wouda

    2016-12-01

    Full Text Available Human movement analysis has become easier with the wide availability of motion capture systems. Inertial sensing has made it possible to capture human motion without external infrastructure, therefore allowing measurements in any environment. As high-quality motion capture data is available in large quantities, this creates possibilities to further simplify hardware setups, by use of data-driven methods to decrease the number of body-worn sensors. In this work, we contribute to this field by analyzing the capabilities of using either artificial neural networks (eager learning or nearest neighbor search (lazy learning for such a problem. Sparse orientation features, resulting from sensor fusion of only five inertial measurement units with magnetometers, are mapped to full-body poses. Both eager and lazy learning algorithms are shown to be capable of constructing this mapping. The full-body output poses are visually plausible with an average joint position error of approximately 7 cm, and average joint angle error of 7 ∘ . Additionally, the effects of magnetic disturbances typical in orientation tracking on the estimation of full-body poses was also investigated, where nearest neighbor search showed better performance for such disturbances.

  3. Heavy metal concentrations and speciation in riverine sediments and the risks posed in three urban belts in the Haihe Basin.

    Science.gov (United States)

    Zhang, Chao; Shan, Baoqing; Tang, Wenzhong; Dong, Lixin; Zhang, Wenqiang; Pei, Yuansheng

    2017-05-01

    Heavy metal (Cr, Cu, Ni, Pb, and Zn) pollution and the risks posed by the heavy metals in riverine sediments in a mountainous urban-belt area (MB), a mountain-plain urban-belt area (MPB), and a plain urban-belt area (PB) in the Haihe Basin, China, were assessed. The enrichment factors indicated that the sediments were more polluted with Cu and Zn than with the other metals, especially in the MPB. The sediments in the MPB were strongly affected by Cu and Zn inputs from anthropogenic sources. The risk assessment codes and individual contamination factors showed that Zn was mobile and posed ecological risks, the exchangeable fractions being 21.1%, 21.2%, and 19.2% of the total Zn concentrations in the samples from the MB, MPB, and PB, respectively. Cr, Cu, and Zn in the sediments from the MPB were potentially highly bioavailable because the non-residual fractions were 56.2%, 54.9%, and 56.5%, respectively, of the total concentrations. The potential risks posed by the heavy metals (determined from the chemical fractions of the heavy metals) in the different areas generally decreased in the order MPB > MB > PB. Pictorial representation of cluster analysis results showed that urbanization development level could cause Cr and Zn pollution in the urban riverine sediments to become more severe. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. The effect of problem posing and problem solving with realistic mathematics education approach to the conceptual understanding and adaptive reasoning

    Science.gov (United States)

    Mahendra, Rengga; Slamet, Isnandar; Budiyono

    2017-12-01

    One of the difficulties of students in learning mathematics is on the subject of geometry that requires students to understand abstract things. The aim of this research is to determine the effect of learning model Problem Posing and Problem Solving with Realistic Mathematics Education Approach to conceptual understanding and students' adaptive reasoning in learning mathematics. This research uses a kind of quasi experimental research. The population of this research is all seventh grade students of Junior High School 1 Jaten, Indonesia. The sample was taken using stratified cluster random sampling technique. The test of the research hypothesis was analyzed by using t-test. The results of this study indicate that the model of Problem Posing learning with Realistic Mathematics Education Approach can improve students' conceptual understanding significantly in mathematics learning. In addition tu, the results also showed that the model of Problem Solving learning with Realistic Mathematics Education Approach can improve students' adaptive reasoning significantly in learning mathematics. Therefore, the model of Problem Posing and Problem Solving learning with Realistic Mathematics Education Approach is appropriately applied in mathematics learning especially on the subject of geometry so as to improve conceptual understanding and students' adaptive reasoning. Furthermore, the impact can improve student achievement.

  5. Conceiving Human Interaction by Visualising Depth Data of Head Pose Changes and Emotion Recognition via Facial Expressions

    Directory of Open Access Journals (Sweden)

    Grigorios Kalliatakis

    2017-07-01

    Full Text Available Affective computing in general and human activity and intention analysis in particular comprise a rapidly-growing field of research. Head pose and emotion changes present serious challenges when applied to player’s training and ludology experience in serious games, or analysis of customer satisfaction regarding broadcast and web services, or monitoring a driver’s attention. Given the increasing prominence and utility of depth sensors, it is now feasible to perform large-scale collection of three-dimensional (3D data for subsequent analysis. Discriminative random regression forests were selected in order to rapidly and accurately estimate head pose changes in an unconstrained environment. In order to complete the secondary process of recognising four universal dominant facial expressions (happiness, anger, sadness and surprise, emotion recognition via facial expressions (ERFE was adopted. After that, a lightweight data exchange format (JavaScript Object Notation (JSON is employed, in order to manipulate the data extracted from the two aforementioned settings. Motivated by the need to generate comprehensible visual representations from different sets of data, in this paper, we introduce a system capable of monitoring human activity through head pose and emotion changes, utilising an affordable 3D sensing technology (Microsoft Kinect sensor.

  6. Real-Time Human Pose Estimation and Gesture Recognition from Depth Images Using Superpixels and SVM Classifier

    Directory of Open Access Journals (Sweden)

    Hanguen Kim

    2015-05-01

    Full Text Available In this paper, we present human pose estimation and gesture recognition algorithms that use only depth information. The proposed methods are designed to be operated with only a CPU (central processing unit, so that the algorithm can be operated on a low-cost platform, such as an embedded board. The human pose estimation method is based on an SVM (support vector machine and superpixels without prior knowledge of a human body model. In the gesture recognition method, gestures are recognized from the pose information of a human body. To recognize gestures regardless of motion speed, the proposed method utilizes the keyframe extraction method. Gesture recognition is performed by comparing input keyframes with keyframes in registered gestures. The gesture yielding the smallest comparison error is chosen as a recognized gesture. To prevent recognition of gestures when a person performs a gesture that is not registered, we derive the maximum allowable comparison errors by comparing each registered gesture with the other gestures. We evaluated our method using a dataset that we generated. The experiment results show that our method performs fairly well and is applicable in real environments.

  7. Intelligent Control of Welding Gun Pose for Pipeline Welding Robot Based on Improved Radial Basis Function Network and Expert System

    Directory of Open Access Journals (Sweden)

    Jingwen Tian

    2013-02-01

    Full Text Available Since the control system of the welding gun pose in whole-position welding is complicated and nonlinear, an intelligent control system of welding gun pose for a pipeline welding robot based on an improved radial basis function neural network (IRBFNN and expert system (ES is presented in this paper. The structure of the IRBFNN is constructed and the improved genetic algorithm is adopted to optimize the network structure. This control system makes full use of the characteristics of the IRBFNN and the ES. The ADXRS300 micro-mechanical gyro is used as the welding gun position sensor in this system. When the welding gun position is obtained, an appropriate pitch angle can be obtained through expert knowledge and the numeric reasoning capacity of the IRBFNN. ARM is used as the controller to drive the welding gun pitch angle step motor in order to adjust the pitch angle of the welding gun in real-time. The experiment results show that the intelligent control system of the welding gun pose using the IRBFNN and expert system is feasible and it enhances the welding quality. This system has wide prospects for application.

  8. THE EFFECT OF PROBLEM POSING APPROACH TOWARDS STUDENTS’ MATHEMATICAL DISPOSITION, CRITICAL & CREATIVE THINKING ABILITY BASED ON SCHOOL LEVEL

    Directory of Open Access Journals (Sweden)

    Adi Nurjaman

    2017-01-01

    Full Text Available The background of this study is the school of the new students of mathematics education courses came from grade high, medium and low. Here the writer wants to see how much influence of the school level on new students’ critical thinking skills and creative mathematical. The purpose of this study was to examine differences in new students’ mathematical disposition, critical & creative thinking ability through the mathematical problem posing approach based on school level (high, medium, low. The method used in this research is the experimental method, with only posttest design. The population of this study is all the students of mathematics education department in Cimahi; while the sample is selected randomly from one college. Then from this chosen college is taken two samples from random class. The instrument of essay test is used to measure students’ critical and mathematical creative thinking ability; while non-test instrument is questionnaire of attitude scale. The results show that: 1 based on the school level (high, medium, and low; there is difference in students’ mathematical critical thinking ability through problem posing approach. 2 based on the school level (high, medium, and low; there is difference in the students’ mathematical critical thinking ability through problem posing approach. 3 based on the school level (high, medium, and low; there is difference in students’ mathematical disposition.

  9. Early experience with the Incisionless Operating Platform™ (IOP) for the treatment of obesity : the Primary Obesity Surgery Endolumenal (POSE) procedure.

    Science.gov (United States)

    Espinós, J C; Turró, R; Mata, A; Cruz, M; da Costa, M; Villa, V; Buchwald, J N; Turró, J

    2013-09-01

    We report our initial experience and 6-month outcomes in a single center using the per-oral Incisionless Operating Platform™ (IOP) (USGI Medical) to place transmural plications in the gastric fundus and distal body using specialized suture anchors (the Primary Obesity Surgery Endolumenal [POSE] procedure). A prospective observational study was undertaken with institutional Ethics Board approval in a private hospital in Barcelona, Spain. Indicated patients were WHO obesity class I-II, or III, where patients refused a surgical approach. Between February 28, 2011 and March 23, 2012, the POSE procedure was successfully performed in 45 patients: 75.6 % female; mean age 43.4 ± 9.2 SD (range 21.0-64.0). At baseline: mean absolute weight (AW, kg), 100.8 ± 12.9 (75.5-132.5); body mass index (BMI, kg/m(2)), 36.7 ± 3.8 (28.1-46.6). A mean 8.2 suture-anchor plications were placed in the fundus, 3.0 along the distal body wall. Mean operative time, 69.2 ± 26.6 min (32.0-126.0); patients were discharged in treatment by discharge. Patients reported less hunger and earlier satiety post procedure. Liquid intake began 12 h post procedure with full solids by 6 weeks. At 6-month follow-up of a prospective case series, the POSE procedure appeared to provide safe and effective weight loss without the scarring, pain, and recovery issues of open and laparoscopic bariatric surgery. Long-term follow-up and further study are required.

  10. Binding pose and affinity prediction in the 2016 D3R Grand Challenge 2 using the Wilma-SIE method

    Science.gov (United States)

    Hogues, Hervé; Sulea, Traian; Gaudreault, Francis; Corbeil, Christopher R.; Purisima, Enrico O.

    2017-10-01

    The Farnesoid X receptor (FXR) exhibits significant backbone movement in response to the binding of various ligands and can be a challenge for pose prediction algorithms. As part of the D3R Grand Challenge 2, we tested Wilma-SIE, a rigid-protein docking method, on a set of 36 FXR ligands for which the crystal structures had originally been blinded. These ligands covered several classes of compounds. To overcome the rigid protein limitations of the method, we used an ensemble of publicly available structures for FXR from the PDB. The use of the ensemble allowed Wilma-SIE to predict poses with average and median RMSDs of 2.3 and 1.4 Å, respectively. It was quite clear, however, that had we used a single structure for the receptor the success rate would have been much lower. The most successful predictions were obtained on chemical classes for which one or more crystal structures of the receptor bound to a molecule of the same class was available. In the absence of a crystal structure for the class, observing a consensus binding mode for the ligands of the class using one or more receptor structures of other classes seemed to be indicative of a reasonable pose prediction. Affinity prediction proved to be more challenging with generally poor correlation with experimental IC50s (Kendall tau 0.3). Even when the 36 crystal structures were used the accuracy of the predicted affinities was not appreciably improved. A possible cause of difficulty is the internal energy strain arising from conformational differences in the receptor across complexes, which may need to be properly estimated and incorporated into the SIE scoring function.

  11. Pose determination of a blade implant in three dimensions from a single two-dimensional radiograph.

    Science.gov (United States)

    Toti, Paolo; Barone, Antonio; Marconcini, Simone; Menchini-Fabris, Giovanni Battista; Martuscelli, Ranieri; Covani, Ugo

    2018-01-11

    The aim of the study was to introduce a mathematical method to estimate the correct pose of a blade by evaluating the radiographic features obtained from a single two-dimensional image. Blade-form implant bed preparation was performed using the piezosurgery device, and placement was attained with the use of magnetic mallet. The pose determination of the blade was described by means of three consecutive rotations defined by three angles of orientation (triplet φ, θ and ψ). Retrospective analysis on periapical radiographs was performed. This method was used to compare implant (axial length along the marker, i.e. the implant structure) vs angular correction factor (a trigonometric function of the triplet). The accuracy of the method was tested by generating two-dimensional radiographic simulations of the blades, which were then compared with the images of the implants as appearing on the real radiographs. Two patients had to be excluded from further evaluation because the values of the estimated pose angles showed a too-wide range to be effective for a good standardization of serial radiographs: intrapatient range from baseline to 1-year survey was > of a threshold determined by the clinicians (30°). The linear dependence between implant (CF°) and angular correction factor (CF^) was estimated by a robust linear regression, yielding the following coefficients: slope, 0.908; intercept, -0.092; and coefficient of determination, 0.924. The absolute error in accuracy was -0.29 ± 4.35, 0.23 ± 3.81 and 0.64 ± 1.18°, respectively, for the angles φ, θ and ψ. The present theoretical and experimental study established the possibility of determining, a posteriori, a unique triplet of angles (φ, θ and ψ) which described the pose of a blade upon a single two-dimensional radiograph, and of suggesting a method to detect cases in which the standardized geometric projection failed. The angular correction of the bone level yielded results very close to those obtained

  12. Landscape, Legal, and Biodiversity Threats that Windows Pose to Birds: A Review of an Important Conservation Issue

    Directory of Open Access Journals (Sweden)

    Daniel Klem Jr.

    2014-03-01

    Full Text Available Windows in human residential and commercial structures in urban, suburban, and rural landscapes contribute to the deaths of billions of birds worldwide. International treaties, federal, provincial, state, and municipal laws exist to reduce human-associated avian mortality, but are most often not enforced for bird kills resulting from window strikes. As an additive, compared to a compensatory mortality factor, window collisions pose threats to the sustainability and overall population health of common as well as species of special concern. Several solutions to address the window hazard for birds exist, but the most innovative and promising need encouragement and support to market, manufacture, and implement.

  13. A Well-Posed Two Phase Flow Model and its Numerical Solutions for Reactor Thermal-Fluids Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kadioglu, Samet Y. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Berry, Ray [Idaho National Lab. (INL), Idaho Falls, ID (United States); Martineau, Richard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-08-01

    A 7-equation two-phase flow model and its numerical implementation is presented for reactor thermal-fluids applications. The equation system is well-posed and treats both phases as compressible flows. The numerical discretization of the equation system is based on the finite element formalism. The numerical algorithm is implemented in the next generation RELAP-7 code (Idaho National Laboratory (INL)’s thermal-fluids code) built on top of an other INL’s product, the massively parallel multi-implicit multi-physics object oriented code environment (MOOSE). Some preliminary thermal-fluids computations are presented.

  14. How is this child feeling? Preschool-aged children’s ability to recognize emotion in faces and body poses

    Science.gov (United States)

    Parker, Alison E.; Mathis, Erin T.; Kupersmidt, Janis B.

    2016-01-01

    The study examined children’s recognition of emotion from faces and body poses, as well as gender differences in these recognition abilities. Preschool-aged children (N = 55) and their parents and teachers participated in the study. Preschool-aged children completed a web-based measure of emotion recognition skills, which included five tasks (three with faces and two with bodies). Parents and teachers reported on children’s aggressive behaviors and social skills. Children’s emotion accuracy on two of the three facial tasks and one of the body tasks was related to teacher reports of social skills. Some of these relations were moderated by child gender. In particular, the relationships between emotion recognition accuracy and reports of children’s behavior were stronger for boys than girls. Identifying preschool-aged children’s strengths and weaknesses in identification of emotion from faces and body poses may be helpful in guiding interventions with children who have problems with social and behavioral functioning that may be due, in part, to emotional knowledge deficits. Further developmental implications of these findings are discussed. PMID:27057129

  15. Robust 3D object localization and pose estimation for random bin picking with the 3DMaMa algorithm

    Science.gov (United States)

    Skotheim, Øystein; Thielemann, Jens T.; Berge, Asbjørn; Sommerfelt, Arne

    2010-02-01

    Enabling robots to automatically locate and pick up randomly placed and oriented objects from a bin is an important challenge in factory automation, replacing tedious and heavy manual labor. A system should be able to recognize and locate objects with a predefined shape and estimate the position with the precision necessary for a gripping robot to pick it up. We describe a system that consists of a structured light instrument for capturing 3D data and a robust approach for object location and pose estimation. The method does not depend on segmentation of range images, but instead searches through pairs of 2D manifolds to localize candidates for object match. This leads to an algorithm that is not very sensitive to scene complexity or the number of objects in the scene. Furthermore, the strategy for candidate search is easily reconfigurable to arbitrary objects. Experiments reported in this paper show the utility of the method on a general random bin picking problem, in this paper exemplified by localization of car parts with random position and orientation. Full pose estimation is done in less than 380 ms per image. We believe that the method is applicable for a wide range of industrial automation problems where precise localization of 3D objects in a scene is needed.

  16. Modifications of Steepest Descent Method and Conjugate Gradient Method Against Noise for Ill-posed Linear Systems

    Directory of Open Access Journals (Sweden)

    Chein-Shan Liu

    2012-04-01

    Full Text Available It is well known that the numerical algorithms of the steepest descent method (SDM, and the conjugate gradient method (CGM are effective for solving well-posed linear systems. However, they are vulnerable to noisy disturbance for solving ill-posed linear systems. We propose the modifications of SDM and CGM, namely the modified steepest descent method (MSDM, and the modified conjugate gradient method (MCGM. The starting point is an invariant manifold defined in terms of a minimum functional and a fictitious time-like variable; however, in the final stage we can derive a purely iterative algorithm including an acceleration parameter. Through the Hopf bifurcation, this parameter indeed plays a major role to switch the situation of slow convergence to a new situation that the functional is stepwisely decreased very fast. Several numerical examples are examined and compared with exact solutions, revealing that the new algorithms of MSDM and MCGM have good computational efficiency and accuracy, even for the highly ill-conditioned linear equations system with a large noise being imposed on the given data.

  17. D3R Grand Challenge 2: blind prediction of protein–ligand poses, affinity rankings, and relative binding free energies

    Science.gov (United States)

    Gaieb, Zied; Liu, Shuai; Gathiaka, Symon; Chiu, Michael; Yang, Huanwang; Shao, Chenghua; Feher, Victoria A.; Walters, W. Patrick; Kuhn, Bernd; Rudolph, Markus G.; Burley, Stephen K.; Gilson, Michael K.; Amaro, Rommie E.

    2018-01-01

    The Drug Design Data Resource (D3R) ran Grand Challenge 2 (GC2) from September 2016 through February 2017. This challenge was based on a dataset of structures and affinities for the nuclear receptor farnesoid X receptor (FXR), contributed by F. Hoffmann-La Roche. The dataset contained 102 IC50 values, spanning six orders of magnitude, and 36 high-resolution co-crystal structures with representatives of four major ligand classes. Strong global participation was evident, with 49 participants submitting 262 prediction submission packages in total. Procedurally, GC2 mimicked Grand Challenge 2015 (GC2015), with a Stage 1 subchallenge testing ligand pose prediction methods and ranking and scoring methods, and a Stage 2 subchallenge testing only ligand ranking and scoring methods after the release of all blinded co-crystal structures. Two smaller curated sets of 18 and 15 ligands were developed to test alchemical free energy methods. This overview summarizes all aspects of GC2, including the dataset details, challenge procedures, and participant results. We also consider implications for progress in the field, while highlighting methodological areas that merit continued development. Similar to GC2015, the outcome of GC2 underscores the pressing need for methods development in pose prediction, particularly for ligand scaffolds not currently represented in the Protein Data Bank (http://www.pdb.org), and in affinity ranking and scoring of bound ligands.

  18. How to pose the question matters: Behavioural Economics concepts in decision making on the basis of ensemble forecasts

    Science.gov (United States)

    Alfonso, Leonardo; van Andel, Schalk Jan

    2014-05-01

    Part of recent research in ensemble and probabilistic hydro-meteorological forecasting analyses which probabilistic information is required by decision makers and how it can be most effectively visualised. This work, in addition, analyses if decision making in flood early warning is also influenced by the way the decision question is posed. For this purpose, the decision-making game "Do probabilistic forecasts lead to better decisions?", which Ramos et al (2012) conducted at the EGU General Assembly 2012 in the city of Vienna, has been repeated with a small group and expanded. In that game decision makers had to decide whether or not to open a flood release gate, on the basis of flood forecasts, with and without uncertainty information. A conclusion of that game was that, in the absence of uncertainty information, decision makers are compelled towards a more risk-averse attitude. In order to explore to what extent the answers were driven by the way the questions were framed, in addition to the original experiment, a second variant was introduced where participants were asked to choose between a sure value (for either loosing or winning with a giving probability) and a gamble. This set-up is based on Kahneman and Tversky (1979). Results indicate that the way how the questions are posed may play an important role in decision making and that Prospect Theory provides promising concepts to further understand how this works.

  19. A well-posed numerical method to track isolated conformal map singularities in Hele-Shaw flow

    Science.gov (United States)

    Baker, Gregory; Siegel, Michael; Tanveer, Saleh

    1995-01-01

    We present a new numerical method for calculating an evolving 2D Hele-Shaw interface when surface tension effects are neglected. In the case where the flow is directed from the less viscous fluid into the more viscous fluid, the motion of the interface is ill-posed; small deviations in the initial condition will produce significant changes in the ensuing motion. This situation is disastrous for numerical computation, as small round-off errors can quickly lead to large inaccuracies in the computed solution. Our method of computation is most easily formulated using a conformal map from the fluid domain into a unit disk. The method relies on analytically continuing the initial data and equations of motion into the region exterior to the disk, where the evolution problem becomes well-posed. The equations are then numerically solved in the extended domain. The presence of singularities in the conformal map outside of the disk introduces specific structures along the fluid interface. Our method can explicitly track the location of isolated pole and branch point singularities, allowing us to draw connections between the development of interfacial patterns and the motion of singularities as they approach the unit disk. In particular, we are able to relate physical features such as finger shape, side-branch formation, and competition between fingers to the nature and location of the singularities. The usefulness of this method in studying the formation of topological singularities (self-intersections of the interface) is also pointed out.

  20. Spherical blurred shape model for 3-D object and pose recognition: quantitative analysis and HCI applications in smart environments.

    Science.gov (United States)

    Lopes, Oscar; Reyes, Miguel; Escalera, Sergio; Gonzàlez, Jordi

    2014-12-01

    The use of depth maps is of increasing interest after the advent of cheap multisensor devices based on structured light, such as Kinect. In this context, there is a strong need of powerful 3-D shape descriptors able to generate rich object representations. Although several 3-D descriptors have been already proposed in the literature, the research of discriminative and computationally efficient descriptors is still an open issue. In this paper, we propose a novel point cloud descriptor called spherical blurred shape model (SBSM) that successfully encodes the structure density and local variabilities of an object based on shape voxel distances and a neighborhood propagation strategy. The proposed SBSM is proven to be rotation and scale invariant, robust to noise and occlusions, highly discriminative for multiple categories of complex objects like the human hand, and computationally efficient since the SBSM complexity is linear to the number of object voxels. Experimental evaluation in public depth multiclass object data, 3-D facial expressions data, and a novel hand poses data sets show significant performance improvements in relation to state-of-the-art approaches. Moreover, the effectiveness of the proposal is also proved for object spotting in 3-D scenes and for real-time automatic hand pose recognition in human computer interaction scenarios.

  1. The tool positioning tutor: a target-pose tracking and display system for learning correct placement of a medical device.

    Science.gov (United States)

    Nelson, Douglas A; Samosky, Joseph T

    2011-01-01

    Safe and successful performance of medical procedures often requires the correct manual positioning of a tool. For example, during endotracheal intubation a laryngoscope is used to open a passage in the airway through which a breathing tube is inserted. During training it can be challenging for an experienced practitioner to effectively communicate to a novice the correct placement and orientation of a tool. We have implemented a real-time tracking and position display system to enhance learning correct laryngoscope placement. The system displays a 3D model of the laryngoscope. A clinical teacher can correctly position the laryngoscope to open the airway of a full-body simulator, then set this tool pose as the target position. The system displays to the learner the fixed, target pose and a real-time display of the current, "live" laryngoscope position. Positional error metrics are displayed as color-coded visual cues to guide the user toward successful targeting of the reference position. This technique provides quantitative assessment of the degree to which a learner has matched a specified "expert" position with a tool, and is potentially applicable to a wide variety of tools and procedures.

  2. An information approach to regularization parameter selection for the solution of ill-posed inverse problems under model misspecification

    Science.gov (United States)

    Urmanov, Aleksey Mikhaylovich

    Engineering problems are often ill-posed, i.e. cannot be solved by conventional data-driven methods such as parametric linear and nonlinear regression or neural networks. A method of regularization that is used for the solution of ill-posed problems requires an a priori choice of the regularization parameter. Several regularization parameter selection methods have been proposed in the literature, yet, none is resistant to model misspecification. Since almost all models are incorrectly or approximately specified, misspecification resistance is a valuable option for engineering applications. Each data-driven method is based on a statistical procedure which can perform well on one data set and can fail on other. Therefore, another useful feature of a data-driven method is robustness. This dissertation proposes a methodology of developing misspecification-resistant and robust regularization parameter selection methods through the use of the information complexity approach. The original contribution of the dissertation to the field of ill-posed inverse problems in engineering is a new robust regularization parameter selection method. This method is misspecification-resistant, i.e. it works consistently when the model is misspecified. The method also improves upon the information-based regularization parameter selection methods by correcting inadequate penalization of estimation inaccuracy through the use of the information complexity framework. Such an improvement makes the proposed regularization parameter selection method robust and reduces the risk of obtaining grossly underregularized solutions. A method of misspecification detection is proposed based on the discrepancy between the proposed regularization parameter selection method and its correctly specified version. A detected misspecification indicates that the model may be inadequate for the particular problem and should be revised. The superior performance of the proposed regularization parameter selection

  3. Hypomagnesaemia Posing as Hypoparathyroidism

    Directory of Open Access Journals (Sweden)

    Sonia Nasreen Ahmad

    2015-09-01

    Full Text Available Persistent hypocalcaemia usually is a presentation of hypoparathyroidism. When it is coupled with low parathormone levels the diagnosis seems almost certain. However, the fact that hypomagnesaemia can give rise to both hypocalcaemia and low parathormone levels gives us points to ponder. This case depicts a young woman soon after childbirth presenting with carpopedal spasm and biochemical abnormalities. Subsequent correction of hypomagnesaemia readjusts calcium, potassium and parathormone levels.

  4. Exercise Sensing and Pose Recovery Inference Tool (ESPRIT) - A Compact Stereo-based Motion Capture Solution For Exercise Monitoring

    Science.gov (United States)

    Lee, Mun Wai

    2015-01-01

    Crew exercise is important during long-duration space flight not only for maintaining health and fitness but also for preventing adverse health problems, such as losses in muscle strength and bone density. Monitoring crew exercise via motion capture and kinematic analysis aids understanding of the effects of microgravity on exercise and helps ensure that exercise prescriptions are effective. Intelligent Automation, Inc., has developed ESPRIT to monitor exercise activities, detect body markers, extract image features, and recover three-dimensional (3D) kinematic body poses. The system relies on prior knowledge and modeling of the human body and on advanced statistical inference techniques to achieve robust and accurate motion capture. In Phase I, the company demonstrated motion capture of several exercises, including walking, curling, and dead lifting. Phase II efforts focused on enhancing algorithms and delivering an ESPRIT prototype for testing and demonstration.

  5. The European Union - a ‘Sui Generis’ International Diplomatic Actor: Challenges Posed to the International Diplomatic Law

    Directory of Open Access Journals (Sweden)

    Ruxandra Laura Boşilcă

    2014-03-01

    Full Text Available It has often been argued that the European Union has a sui generis status by being less than a nation-state, but more than an international organization, which is also reflected in its conduct of diplomatic relations with third states and international organizations. Since its inception, the European Union has managed to set a wide bi- and multilateral diplomatic network – which is subject to the provisions of the 1961 Vienna Convention on Diplomatic Relations (VCDR. This paper’s purpose is to analyze some of the main challenges posed to the international diplomatic law by the EU’s emergence on the diplomatic scene, in the light of the significant transformations brought by the Lisbon Treaty.

  6. Lead and Cadmium: Priorities for action from UNEP’s perspective for addressing risks posed by these two heavy metals

    Directory of Open Access Journals (Sweden)

    Piper D.

    2013-04-01

    Full Text Available The United Nations Environment Programme (UNEP has been focusing on actions with regard to lead and cadmium since 2001 when the work of the Partnership for Clean Fuels and Vehicles (PCFV was initiated. The development and finalization of the reviews of scientific information on lead and cadmium facilitated discussions among Governments in relation to the need for global action with regard to these heavy metals. UNEP continues to address priority areas for focusing to reduce risks posed by lead and cadmium. The Global Alliance to Eliminate Lead Paint (GAELP is a clear example for addressing those risks; however more work is expected to be done in relation to these key issues.

  7. Quantifying the risk that marine debris poses to cetaceans in coastal waters of the 4-island region of Maui.

    Science.gov (United States)

    Currie, Jens J; Stack, Stephanie H; McCordic, Jessica A; Kaufman, Gregory D

    2017-08-15

    Marine debris poses considerable threat to biodiversity and ecosystems and has been identified as a stressor for a variety of marine life. Here we present results from the first study quantifying the amount and type of debris accumulation in Maui leeward waters and relate this to cetacean distribution to identify areas where marine debris may present a higher threat. Transect surveys were conducted within the 4-island region of Maui, Hawai'i from April 1, 2013 to April 15, 2016. Debris was found in all areas of the study region with higher concentrations observed where the Au'au, Kealaikahiki, and Alalakeiki channels converge. The degree of overlap between debris and cetaceans varied among species but was largest for humpback whales, which account for the largest portion of reported entanglements in the 4-island region of Maui. Identifying areas of high debris-cetacean density overlap can facilitate species management and debris removal efforts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Evaluating health risks posed by heavy metals to humans consuming blood cockles (Anadara granosa) from the Upper Gulf of Thailand.

    Science.gov (United States)

    Sudsandee, Suntorn; Tantrakarnapa, Kraichat; Tharnpoophasiam, Prapin; Limpanont, Yanin; Mingkhwan, Ratchaneekorn; Worakhunpiset, Suwalee

    2017-06-01

    There is global concern about heavy metal contamination in the environment. Adverse health effects can be caused by heavy metals in contaminated food and water. Therefore, environmental monitoring studies and risk assessments should be conducted periodically. In this study, we measured levels of Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn in blood cockles (Anadara granosa) collected from three locations in the Upper Gulf of Thailand. Hazard quotients and hazard indices were calculated to evaluate the health risks posed by heavy metals in consumed blood cockles. Heavy metal concentrations in all of the blood cockle samples were lower than the relevant food standards. The hazard quotients and hazard indices were heavy metals in blood cockles over a human lifetime.

  9. Consistent Treatment of Variables and Causation Poses a Challenge for Behavioral Research Methods: A Commentary on Nesselroade and Molenaar (2016).

    Science.gov (United States)

    Markus, Keith A

    2016-01-01

    Nesselroade and Molenaar presented the ideographic filter as a proposal for analyzing lawful regularities in behavioral research. The proposal highlights an inconsistency that poses a challenge for behavioral research more generally. One can distinguish a broadly Humean approach from a broadly non-Humean approach as they relate to variables and to causation. Nesselroade and Molenaar rejected a Humean approach to latent variables that characterizes them as nothing more than summaries of their manifest indicators. By contrast, they tacitly accepted a Humean approach to causes characterized as nothing more than summaries of their manifest causal effects. A non-Humean treatment of variables coupled with a Humean treatment of causation creates a theoretical tension within their proposal. For example, one can interpret the same model elements as simultaneously representing both variables and causes. Future refinement of the ideographic filter proposal to address this tension could follow any of a number of strategies.

  10. Pose estimation and representation of cylinders from single two-dimensional images in modeling remotely operated vehicle (ROV) environments

    Science.gov (United States)

    Volden, Rune

    1994-10-01

    In this paper a method is proposed on how to extract cylinders from single 2D images. The operator restricts the search area for the image ellipse from the projected cylinder, and a least- square ellipse is obtained and verified by the operator. By knowing the radius and length of the cylinder, an algorithm using projective geometry back projects the image ellipse to a circle in three-space. The center and normal vector to this circle are obtained. If both cylinder tangents are visible, a better estimate of cylinder axis is obtained. From this a synthetic cylinder is computed and projected onto the original image. If the synthetic cylinder is a good fit, it is transferred to a CAD model of the environment, which is updated. The operator receives an updated version of the environment, which either includes a new cylinder or a better pose estimate of one of the previously identified cylinders.

  11. Escarpment seeps at Shiprock, New Mexico. [Risk posed by seep water to human health and the environment

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    The purpose of this report is to characterize the seeps identified at the Shiprock UMTRA Project site during the prelicensing custodial care inspection conducted in December of 1990, to evaluate the relationship between the seeps and uranium processing activities or tailings disposal, and to evaluate the risk posed by the seep water to human health and the environment. The report provides a brief description of the geology, groundwater hydrology, and surface water hydrology. The locations of the seeps and monitor wells are identified, and the water quality of the seeps and groundwater is discussed in the context of past activities at the site. The water quality records for the site are presented in tables and appendices; this information was used in the risk assessment of seep water.

  12. Joint registration of ultrasound, CT and a shape+pose statistical model of the lumbar spine for guiding anesthesia.

    Science.gov (United States)

    Behnami, Delaram; Seitel, Alexander; Rasoulian, Abtin; Anas, Emran Mohammad Abu; Lessoway, Victoria; Osborn, Jill; Rohling, Robert; Abolmaesumi, Purang

    2016-06-01

    Facet joint injections and epidural needle insertions are widely used for spine anesthesia. Accurate needle placement is important for effective therapy delivery and avoiding complications arising from damage of soft tissue and nerves. Needle guidance is usually performed by fluoroscopy or palpation, resulting in radiation exposure and multiple needle re-insertions. Several ultrasound (US)-based approaches have been proposed but have not found wide acceptance in clinical routine. This is mainly due to difficulties in interpretation of the complex spinal anatomy in US, which leads to clinicians' lack of confidence in relying only on information derived from US for needle guidance. We introduce a multimodal joint registration technique that takes advantage of easy-to-interpret preprocedure computed topography (CT) scans of the lumbar spine to concurrently register a shape+pose model to the intraprocedure 3D US. Common shape coefficients are assumed between two modalities, while pose coefficients are specific to each modality. The joint method was evaluated on patient data consisting of ten pairs of US and CT scans of the lumbar spine. It was successfully applied in all cases and yielded an RMS shape error of 2.1 mm compared to the CT ground truth. The joint registration technique was compared to a previously proposed method of statistical model to US registration Rasoulian et al. (Information processing in computer-assisted interventions. Springer, Berlin, pp 51-60, 2013). The joint framework improved registration accuracy to US in 7 out of 17 visible vertebrae, belonging to four patients. In the remaining cases, the two methods were equally accurate. The joint registration allows visualization and augmentation of important anatomy in both the US and CT domain and improves the registration accuracy in both modalities. Observing the patient-specific model in the CT domain allows the clinicians to assess the local registration accuracy qualitatively, which is likely

  13. Pose-aware C-arm for automatic re-initialization of interventional 2D/3D image registration.

    Science.gov (United States)

    Fotouhi, Javad; Fuerst, Bernhard; Johnson, Alex; Lee, Sing Chun; Taylor, Russell; Osgood, Greg; Navab, Nassir; Armand, Mehran

    2017-07-01

    In minimally invasive interventions assisted by C-arm imaging, there is a demand to fuse the intra-interventional 2D C-arm image with pre-interventional 3D patient data to enable surgical guidance. The commonly used intensity-based 2D/3D registration has a limited capture range and is sensitive to initialization. We propose to utilize an opto/X-ray C-arm system which allows to maintain the registration during intervention by automating the re-initialization for the 2D/3D image registration. Consequently, the surgical workflow is not disrupted and the interaction time for manual initialization is eliminated. We utilize two distinct vision-based tracking techniques to estimate the relative poses between different C-arm arrangements: (1) global tracking using fused depth information and (2) RGBD SLAM system for surgical scene tracking. A highly accurate multi-view calibration between RGBD and C-arm imaging devices is achieved using a custom-made multimodal calibration target. Several in vitro studies are conducted on pelvic-femur phantom that is encased in gelatin and covered with drapes to simulate a clinically realistic scenario. The mean target registration errors (mTRE) for re-initialization using depth-only and RGB [Formula: see text] depth are 13.23 mm and 11.81 mm, respectively. 2D/3D registration yielded 75% success rate using this automatic re-initialization, compared to a random initialization which yielded only 23% successful registration. The pose-aware C-arm contributes to the 2D/3D registration process by globally re-initializing the relationship of C-arm image and pre-interventional CT data. This system performs inside-out tracking, is self-contained, and does not require any external tracking devices.

  14. Structural insights from binding poses of CCR2 and CCR5 with clinically important antagonists: a combined in silico study.

    Directory of Open Access Journals (Sweden)

    Gugan Kothandan

    Full Text Available Chemokine receptors are G protein-coupled receptors that contain seven transmembrane domains. In particular, CCR2 and CCR5 and their ligands have been implicated in the pathophysiology of a number of diseases, including rheumatoid arthritis and multiple sclerosis. Based on their roles in disease, they have been attractive targets for the pharmaceutical industry, and furthermore, targeting both CCR2 and CCR5 can be a useful strategy. Owing to the importance of these receptors, information regarding the binding site is of prime importance. Structural studies have been hampered due to the lack of X-ray crystal structures, and templates with close homologs for comparative modeling. Most of the previous models were based on the bovine rhodopsin and β2-adrenergic receptor. In this study, based on a closer homolog with higher resolution (CXCR4, PDB code: 3ODU 2.5 Å, we constructed three-dimensional models. The main aim of this study was to provide relevant information on binding sites of these receptors. Molecular dynamics simulation was done to refine the homology models and PROCHECK results indicated that the models were reasonable. Here, binding poses were checked with some established inhibitors of high pharmaceutical importance against the modeled receptors. Analysis of interaction modes gave an integrated interpretation with detailed structural information. The binding poses confirmed that the acidic residues Glu291 (CCR2 and Glu283 (CCR5 are important, and we also found some additional residues. Comparisons of binding sites of CCR2/CCR5 were done sequentially and also by docking a potent dual antagonist. Our results can be a starting point for further structure-based drug design.

  15. Sustainable Materials Management (SMM) Web Academy Webinar: An Introduction to Lithium Batteries and the Challenges that they Pose to the Waste and Recycling Industry

    Science.gov (United States)

    This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled, An Introduction to Lithium Batteries and the Challenges that they Pose to the Waste and Recycling Industry.

  16. The Physical Demands of the Tree (Vriksasana and One-Leg Balance (Utthita Hasta Padangusthasana Poses Performed by Seniors: A Biomechanical Examination

    Directory of Open Access Journals (Sweden)

    Sean S.-Y. Yu

    2012-01-01

    and frontal planes (=0.13–0.98. Similarly, OLB introductory and intermediate variations induced sagittal JMOFs that were in the opposite direction of the classic advanced pose version at the hip and knee (<.001; =0.98–2.36. These biomechanical insights provide evidence that may be used by instructors, clinicians and therapists when selecting pose modifications for their yoga participants.

  17. Evaluation of human health risks posed by carcinogenic and non-carcinogenic multiple contaminants associated with consumption of fish from Taihu Lake, China.

    Science.gov (United States)

    Yu, Yingxin; Wang, Xinxin; Yang, Dan; Lei, Bingli; Zhang, Xiaolan; Zhang, Xinyu

    2014-07-01

    The present study estimated the human daily intake and uptake of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), and toxic trace elements [mercury (Hg), chromium (Cr), cadmium (Cd), and arsenic (As)] due to consumption of fish from Taihu Lake, China, and the associated potential health risks posed by these contaminants. The health risks posed by the contaminants were assessed using a risk quotient of the fish consumption rate to the maximum allowable fish consumption rate considering the contaminants for carcinogenic and non-carcinogenic effect endpoints. The results showed that fish consumption would not pose non-cancer risks. However, some species would cause a cancer risk. Relative risks of the contaminants were calculated to investigate the contaminant which posed the highest risk to humans. As a result, in view of the contaminants for carcinogenic effects, As was the contaminant which posed the highest risk to humans. However, when non-carcinogenic effects of the contaminants were considered, Hg posed the highest risk. The risk caused by PBDEs was negligible. The results demonstrated that traditional contaminants, such as As, Hg, DDTs (dichlorodiphenyltrichloroethane and its metabolites), and PCBs, require more attention in Taihu Lake than the other target contaminants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Fuzzy-Appearance Manifold and Fuzzy-Nearest Distance Calculation for Model-Less 3D Pose Estimation of Degraded Face Images

    Directory of Open Access Journals (Sweden)

    Benyamin Kusumoputro

    2013-01-01

    Full Text Available This paper presents the development of fuzzy-appearance manifold and fuzzy-nearest distance calculation in the eigenspace domain for pose estimation of degraded face images. In order to obtain a robust pose estimation system which can deal with the fuzziness of face data caused by statistical errors, we proposed the fuzzy-vector representation in eigenspace domain of the face images. Using fuzzy-vector representations, all of the crisp vectors of face data in the eigenspace domain are firstly transformed into fuzzy-vectors as fuzzy-points. Next, the fuzzy-appearance manifold is constructed from all the available fuzzy-points and the fuzzy-nearest distance calculation is proposed as the classifier of the pose estimation system. The pose estimation of an unknown face image is performed by firstly being projected onto the eigenspace domain then transformed to become an unknown fuzzy-point, and its fuzzy-distance with all of the available fuzzy-points in the fuzzy-appearance manifold will be calculated. The fuzzy-point in the manifold which has the nearest distance to that unknown fuzzy-point will be determined as the pose position of the unknown face image. In the experiment, face images with various quality degradation effects were used. The results show that the system could maintain high recognition rates for estimating the pose position of the degraded face images.

  19. SU-G-JeP3-03: Effect of Robot Pose On Beam Blocking for Ultrasound Guided SBRT of the Prostate

    Energy Technology Data Exchange (ETDEWEB)

    Gerlach, S; Schlaefer, A [Hamburg University of Technology, Hamburg (Germany); Kuhlemann, I; Ernst, F [Universitaet zu Luebeck, Luebeck (Germany); Fuerweger, C [European Cyberknife Center Munich, Munich (Germany)

    2016-06-15

    Purpose: Ultrasound presents a fast, volumetric image modality for real-time tracking of abdominal organ motion. How-ever, ultrasound transducer placement during radiation therapy is challenging. Recently, approaches using robotic arms for intra-treatment ultrasound imaging have been proposed. Good and reliable imaging requires placing the transducer close to the PTV. We studied the effect of a seven degrees of freedom robot on the fea-sible beam directions. Methods: For five CyberKnife prostate treatment plans we established viewports for the transducer, i.e., points on the patient surface with a soft tissue view towards the PTV. Choosing a feasible transducer pose and using the kinematic redundancy of the KUKA LBR iiwa robot, we considered three robot poses. Poses 1 to 3 had the elbow point anterior, superior, and inferior, respectively. For each pose and each beam starting point, the pro-jections of robot and PTV were computed. We added a 20 mm margin accounting for organ / beam motion. The number of nodes for which the PTV was partially of fully blocked were established. Moreover, the cumula-tive overlap for each of the poses and the minimum overlap over all poses were computed. Results: The fully and partially blocked nodes ranged from 12% to 20% and 13% to 27%, respectively. Typically, pose 3 caused the fewest blocked nodes. The cumulative overlap ranged from 19% to 29%. Taking the minimum overlap, i.e., considering moving the robot’s elbow while maintaining the transducer pose, the cumulative over-lap was reduced to 16% to 18% and was 3% to 6% lower than for the best individual pose. Conclusion: Our results indicate that it is possible to identify feasible ultrasound transducer poses and to use the kinematic redundancy of a 7 DOF robot to minimize the impact of the imaging subsystem on the feasible beam directions for ultrasound guided and motion compensated SBRT. Research partially funded by DFG grants ER 817/1-1 and SCHL 1844/3-1.

  20. Definition of anatomical zero positions for assessing shoulder pose with 3D motion capture during bilateral abduction of the arms.

    Science.gov (United States)

    Rettig, Oliver; Krautwurst, Britta; Maier, Michael W; Wolf, Sebastian I

    2015-12-09

    Surgical interventions at the shoulder may alter function of the shoulder complex. Clinically, the outcome can be assessed by universal goniometry. Marker-based motion capture may not resemble these results due to differing angle definitions. The clinical inspection of bilateral arm abduction for assessing shoulder dysfunction is performed with a marker based 3D optical measurement method. An anatomical zero position of shoulder pose is proposed to determine absolute angles according to the Neutral-0-Method as used in orthopedic context. Static shoulder positions are documented simultaneously by 3D marker tracking and universal goniometry in 8 young and healthy volunteers. Repetitive bilateral arm abduction movements of at least 150° range of motion are monitored. Similarly a subject with gleno-humeral osteoarthritis is monitored for demonstrating the feasibility of the method and to illustrate possible shoulder dysfunction effects. With mean differences of less than 2°, the proposed anatomical zero position results in good agreement between shoulder elevation/depression angles determined by 3D marker tracking and by universal goniometry in static positions. Lesser agreement is found for shoulder pro-/retraction with systematic deviations of up to 6°. In the bilateral arm abduction movements the volunteers perform a common and specific pattern in clavicula-thoracic and gleno-humeral motion with maximum shoulder angles of 32° elevation, 5° depression and 45° protraction, respectively, whereas retraction is hardly reached. Further, they all show relevant out of (frontal) plane motion with anteversion angles of 30° in overhead position (maximum abduction). With increasing arm anteversion the shoulder is increasingly retroverted, with a maximum of 20° retroversion. The subject with gleno-humeral osteoarthritis shows overall less shoulder abduction range of motion but with increased out-of-plane movement during abduction. The proposed anatomical zero definition

  1. Challenges posed by diversity in Academic institutions as they implement Information Literacy: the experiences of Makerere University Library in Uganda

    Directory of Open Access Journals (Sweden)

    Faith Beatrice Akiteng

    2010-09-01

    Full Text Available Over the years, academic libraries have been conducting information literacy (IL programmes for their users. This paper shares Makerere University Library's experience in implementing IL programmes at Makerere University and other academic institutions of learning in Uganda. The findings of this paper are based on the IL sessions' evaluation forms, together with the authors' experiences as instructors. A sample of one thousand (1000 participants' evaluation feedback forms was used in assessing the IL sessions conducted by Makerere University Library in two years (2008-2009. The evaluation focused on the duration and relevancy of training, nature of content, its organization; the instructors, new skills participants gained and how they hoped to pass them to others. Initial findings indicate that IL sessions are highly regarded with repeated recommendations for increased duration and frequency of information literacy sessions in different universities. The various challenges posed by diversity are explained as follows: Difference in age groups arise because admissions to the various universities cater for direct entrants from high school and mature age entrants'. Students also come from different social backgrounds that dictate the standard of schools they attend i.e.; urban schools where education standards are high and skills such as using computers are imparted visa-a-vis the rural schools where such skills are not imparted. To the IL instructor, this implies conducting the training with patience and extending the time allocated for each session in order to impart the basic ICT skills prior to imparting the IL skills. Internationalization on the other hand is not a very big challenge because the proportion of foreign students is small and their ICT skills are moderate. Gender aspects and the diverse disciplines of research in the Ugandan universities also pose challenges when conducting IL sessions in that the groups handled at a time are

  2. What Butterfly Effect? The Contextual Differences in Public Perceptions of the Health Risk Posed by Climate Change

    Directory of Open Access Journals (Sweden)

    James W. Stoutenborough

    2015-08-01

    Full Text Available One of the most difficult aspects of persuading the public to support climate change policy is the lack of recognition that climate change will likely have a direct impact on an individual’s life. Anecdotal evidence and arguments within the media suggest that those who are skeptical of climate change are more likely to believe that the negative externalities associated with climate change will be experienced by others, and, therefore, are not a concern to that individual. This project examines public perceptions of the health risk posed by climate change. Using a large national public opinion survey of adults in the United States, respondents were asked to evaluate the health risk for themselves, their community, the United States, and the world. The results suggest that individuals evaluate the risk for each of these contexts differently. Statistical analyses are estimated to identify the determinants of each risk perception to identify their respective differences. The implications of these findings on support for climate change policy are discussed.

  3. Does the groundwater nitrate pollution in China pose a risk to human health? A critical review of published data.

    Science.gov (United States)

    Zhai, Yuanzheng; Lei, Yan; Wu, Jin; Teng, Yanguo; Wang, Jinsheng; Zhao, Xiaobing; Pan, Xiaodong

    2017-02-01

    Nitrate pollution has pervaded many parts of the world, especially in developing countries such as China. Based on the available groundwater nitrate data sets in China (2000-2015), the groundwater pollution levels at the provincial scale are evaluated which contains 33 provinces (units) except for Macau because of lacking data. Then, the potential risks posed to human health in national scale are quantified. In order to make the results more precise and systematical, both drinking and dermal contact exposure pathways are considered, and the influenced crowd are more finely divided into four groups to study the impacts of age and gender on the outcome, which include infants (0-6 months), children (7 months-17 years old), adult males (18 years old-), and adult females (18 years old-). Results indicate that there are seven units whose groundwater nitrate concentrations exceed the standard value with Shaanxi being a seriously poor condition. Facing the same level of nitrate, the health risk level changes in the order of infants > children > adult males > adult females. That is to say, minors and males are more vulnerable compared with adults and females, respectively. There is no adverse effect on adult females of the whole country, while gender really impacts on the health risk assessment result. Adult males, children, and infants face various degrees of health risk respectively in Shaanxi and Shandong, which are needed to pay more attention to.

  4. A preliminary approach to quantifying the overall environmental risks posed by development projects during environmental impact assessment

    Science.gov (United States)

    Chadès, Iadine

    2017-01-01

    Environmental impact assessment (EIA) is used globally to manage the impacts of development projects on the environment, so there is an imperative to demonstrate that it can effectively identify risky projects. However, despite the widespread use of quantitative predictive risk models in areas such as toxicology, ecosystem modelling and water quality, the use of predictive risk tools to assess the overall expected environmental impacts of major construction and development proposals is comparatively rare. A risk-based approach has many potential advantages, including improved prediction and attribution of cause and effect; sensitivity analysis; continual learning; and optimal resource allocation. In this paper we investigate the feasibility of using a Bayesian belief network (BBN) to quantify the likelihood and consequence of non-compliance of new projects based on the occurrence probabilities of a set of expert-defined features. The BBN incorporates expert knowledge and continually improves its predictions based on new data as it is collected. We use simulation to explore the trade-off between the number of data points and the prediction accuracy of the BBN, and find that the BBN could predict risk with 90% accuracy using approximately 1000 data points. Although a further pilot test with real project data is required, our results suggest that a BBN is a promising method to monitor overall risks posed by development within an existing EIA process given a modest investment in data collection. PMID:28686651

  5. Local binary pattern variants-based adaptive texture features analysis for posed and nonposed facial expression recognition

    Science.gov (United States)

    Sultana, Maryam; Bhatti, Naeem; Javed, Sajid; Jung, Soon Ki

    2017-09-01

    Facial expression recognition (FER) is an important task for various computer vision applications. The task becomes challenging when it requires the detection and encoding of macro- and micropatterns of facial expressions. We present a two-stage texture feature extraction framework based on the local binary pattern (LBP) variants and evaluate its significance in recognizing posed and nonposed facial expressions. We focus on the parametric limitations of the LBP variants and investigate their effects for optimal FER. The size of the local neighborhood is an important parameter of the LBP technique for its extraction in images. To make the LBP adaptive, we exploit the granulometric information of the facial images to find the local neighborhood size for the extraction of center-symmetric LBP (CS-LBP) features. Our two-stage texture representations consist of an LBP variant and the adaptive CS-LBP features. Among the presented two-stage texture feature extractions, the binarized statistical image features and adaptive CS-LBP features were found showing high FER rates. Evaluation of the adaptive texture features shows competitive and higher performance than the nonadaptive features and other state-of-the-art approaches, respectively.

  6. An infrared range camera-based approach for three-dimensional locomotion tracking and pose reconstruction in a rodent.

    Science.gov (United States)

    Ou-Yang, Tai-Hsien; Tsai, Meng-Li; Yen, Chen-Tung; Lin, Ta-Te

    2011-09-30

    We herein introduce an automated three-dimensional (3D) locomotion tracking and pose reconstruction system for rodents with superior robustness, rapidity, reliability, resolution, simplicity, and cost. An off-the-shelf composite infrared (IR) range camera was adopted to grab high-resolution depth images (640×480×2048 pixels at 20Hz) in our system for automated behavior analysis. For the inherent 3D structure of the depth images, we developed a compact algorithm to reconstruct the locomotion and body behavior with superior temporal and solid spatial resolution. Since the range camera operates in the IR spectrum, interference from the visible light spectrum did not affect the tracking performance. The accuracy of our system was 98.1±3.2%. We also validated the system, which yielded strong correlation with automated and manual tracking. Meanwhile, the system replicates a detailed dynamic rat model in virtual space, which demonstrates the movements of the extremities of the body and locomotion in detail on varied terrain. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Posing the problem of time in S. N. Bulgakov: in the context of nature and freedom antinomy

    Directory of Open Access Journals (Sweden)

    Tatiana Rezvykh

    2015-06-01

    Full Text Available The author discusses a S. N. Bulgakov’s unique approach to the problem of time, consisting of an effort to resolve the problem basing on corollaries from Kant’s antinomy of nature and freedom, as well as on ideas of Schelling. Bulgakov views the time antinomically. It was his reflection on the meaning of Kant’s antinomism which led him to posing the problem of time. For the first time we find him treating this problem in his article Apocalypticism and Socialism, which dealt with antinomy of eschatology and chiliasm. Here also he starts to consider relation of time and eternity through antinomy of nature and freedom. In his Philosophy of Economy the same problem is solved by means of the concept of Sophia as the ontological basis of personality, which unites freedom and nature, the eternal and the temporal. But in his Unfading Light the antinomy of nature and freedom is discussed through differentiation between negative and positive theology. Bulgakov uses as a synthesizing concept Schelling’s idea of «eternal time» as unity of eternity and time. Thus, despite Bulgakov’s repeated statements about their clear distinction, time and eternity are drawn together. Such an attempt to solve the problem of time raises doubts about the very possibility of freedom.

  8. Sensitivity of joint kinematics and kinetics to different pose estimation algorithms and joint constraints in the elderly.

    Science.gov (United States)

    Moniz-Pereira, Vera; Cabral, Silvia; Carnide, Filomena; Veloso, António P

    2014-06-01

    The purpose of this research was to study the sensitivity of lower limb joint kinematics and kinetics, calculated during different functional tasks (walking, stair descent and stair ascent) in a sample of older adults, to different pose estimation algorithms and models' joint constraints. Three models were developed and optimized differently: in one model, each segment had 6 degrees of freedom (segment optimization, SO), while in the other two, global optimization (GO) was used, with different joint constraints: (1) GO, allowing all joint rotations; (2) GOR, allowing three rotations at the hip, one at the knee (flexion/extension) and two at the ankle (dorsi/plantar flexion and eversion/inversion). The results showed that joint angles are more sensitive to the model's constraints than joint moments and, the more restrictive the model, the higher the differences between models, especially for the frontal and transverse planes (max. RMS difference during gait: 11.7 degrees (64%) vs 0.12 N·m/kg (35.4%). In addition, except for knee abduction/adduction angle, differences between SO and GO models were relatively low. Since GO avoids the nonanatomical dislocations sometimes observed in SO, choosing this model seems to be reasonable for future studies with a similar sample and study design.

  9. A preliminary approach to quantifying the overall environmental risks posed by development projects during environmental impact assessment.

    Science.gov (United States)

    Nicol, Sam; Chadès, Iadine

    2017-01-01

    Environmental impact assessment (EIA) is used globally to manage the impacts of development projects on the environment, so there is an imperative to demonstrate that it can effectively identify risky projects. However, despite the widespread use of quantitative predictive risk models in areas such as toxicology, ecosystem modelling and water quality, the use of predictive risk tools to assess the overall expected environmental impacts of major construction and development proposals is comparatively rare. A risk-based approach has many potential advantages, including improved prediction and attribution of cause and effect; sensitivity analysis; continual learning; and optimal resource allocation. In this paper we investigate the feasibility of using a Bayesian belief network (BBN) to quantify the likelihood and consequence of non-compliance of new projects based on the occurrence probabilities of a set of expert-defined features. The BBN incorporates expert knowledge and continually improves its predictions based on new data as it is collected. We use simulation to explore the trade-off between the number of data points and the prediction accuracy of the BBN, and find that the BBN could predict risk with 90% accuracy using approximately 1000 data points. Although a further pilot test with real project data is required, our results suggest that a BBN is a promising method to monitor overall risks posed by development within an existing EIA process given a modest investment in data collection.

  10. The English and northern (Sweden and Norway) systems regarding the questions posed by the white book; Les systemes anglais et nordiques (Suede et Norvege) au regard des questions posees dans le livre blanc

    Energy Technology Data Exchange (ETDEWEB)

    Secretariat d' Etat a l' Industrie [ed.] [Secretariat d' Etat a l' Industrie, Ministere de l' Economie, des Finances et de l' Industrie, Paris (France)

    1999-06-15

    This report issued at request of Ministry of Economy, Finances and Industry - State Secretariat for Industry, presents an analysis of the way the European countries have liberalized their markets, which will be used to answer the questions posed by the white book titled 'Towards the future organization of the French electricity sector'. In the United Kingdom the reform, initiated on 1 April 1990, occurred as a genuine revolution, with the blow-up of CEGB, the equivalent of EDF in France. In Swede and Norway the evolution was progressive; the electric industry was actually not nationalized and the local collectivities, often owners of the production means, have remained the prominent actors. Other characteristic of these countries is the abundance of natural energetic resources, especially for United Kingdom and Norway where the objective of the power policy is of turning profitable the existent potential and not as in France, where the problem is to cope with the consequences of the lack of natural resources. This report contains two parts. The first part presents the main characteristics of the liberalized systems. Indeed while in an integrated system the logic is 'top - down', in a liberalized system the logic is 'bottom - up' i.e., the coordination is based on the market in a decentralized way. The instrument of this coordination is a contract by which the risks are shared among the actors (producers, bankers, distributors, customers). The central actor of the liberalized system is the network authority, so-called 'independent' with rather large autonomy, nominated by the Minister in charge with the energy policy. The network authority has essentially two functions: control and surveillance. In United Kingdom this agency has among his duties the promotion of competition, particularly in production sector, considered as still having monopole capabilities. In Swede and Norway this authority contents itself of only issuing

  11. Ranking docking poses by graph matching of protein-ligand interactions: lessons learned from the D3R Grand Challenge 2

    Science.gov (United States)

    da Silva Figueiredo Celestino Gomes, Priscila; Da Silva, Franck; Bret, Guillaume; Rognan, Didier

    2017-08-01

    A novel docking challenge has been set by the Drug Design Data Resource (D3R) in order to predict the pose and affinity ranking of a set of Farnesoid X receptor (FXR) agonists, prior to the public release of their bound X-ray structures and potencies. In a first phase, 36 agonists were docked to 26 Protein Data Bank (PDB) structures of the FXR receptor, and next rescored using the in-house developed GRIM method. GRIM aligns protein-ligand interaction patterns of docked poses to those of available PDB templates for the target protein, and rescore poses by a graph matching method. In agreement with results obtained during the previous 2015 docking challenge, we clearly show that GRIM rescoring improves the overall quality of top-ranked poses by prioritizing interaction patterns already visited in the PDB. Importantly, this challenge enables us to refine the applicability domain of the method by better defining the conditions of its success. We notably show that rescoring apolar ligands in hydrophobic pockets leads to frequent GRIM failures. In the second phase, 102 FXR agonists were ranked by decreasing affinity according to the Gibbs free energy of the corresponding GRIM-selected poses, computed by the HYDE scoring function. Interestingly, this fast and simple rescoring scheme provided the third most accurate ranking method among 57 contributions. Although the obtained ranking is still unsuitable for hit to lead optimization, the GRIM-HYDE scoring scheme is accurate and fast enough to post-process virtual screening data.

  12. Effect of the gingival display on posed smile with different facial forms: a comparison of dentists and patients concepts.

    Science.gov (United States)

    Akhare, Pankaj J; Daga, Akshay

    2012-01-01

    The aim of this study was to evaluate and compare the importance of amount of gingival display on smile esthetics and facial attractiveness in males and females with different facial forms by orthodontists as well as lay person. Frontal photographs of 18 male and female patients (9 male and 9 female) each, at a posed smile, seeking treatment in the Department of Orthodontics and Dentofacial Orthopedics were obtained. The photographs were divided in 3 groups based on their facial forms (Short face, Average face and Long face) and were altered by moving the dentition within the lip frame of the captured photograph to bring about different gingival display at smile. The pictures were divided into six groups with gingival exposures of 0 mm, 1 mm, 2 mm, 3 mm, 4 mm and 5 mm. The pictures were rated for attractiveness by four sets of evaluators - male and female Orthodontists and male and female lay evaluators. The statistical analysis methods used for the study included Mean score calculation, standard deviation and Analysis of variance: [test (Mono- Variance)]. The Student t test (two tailed, independent) has been used to find the significance of rating scores between lay person and orthodontist, and also between males and females evaluators. No significant difference in ratings of gingival display in the 3 groups of photographs was noted by lay person and orthodontists. The results point to the fact that the influence of amount of gingival display on smile esthetics was independent of the facial form. It was also observed that gingival display of 0 mm to 2 mm was acceptable to both the lay person and the orthodontists. As the amount of gingival display increased, the ratings for facial attractiveness by both orthodontists and lay person decreased. Higher scores were given by both orthodontists and lay person for photographs which showed gingival display of 0-2 mm, suggesting this value to be most acceptable.

  13. Simultaneous Multi-Structure Segmentation and 3D Nonrigid Pose Estimation in Image-Guided Robotic Surgery.

    Science.gov (United States)

    Nosrati, Masoud S; Abugharbieh, Rafeef; Peyrat, Jean-Marc; Abinahed, Julien; Al-Alao, Osama; Al-Ansari, Abdulla; Hamarneh, Ghassan

    2016-01-01

    In image-guided robotic surgery, segmenting the endoscopic video stream into meaningful parts provides important contextual information that surgeons can exploit to enhance their perception of the surgical scene. This information provides surgeons with real-time decision-making guidance before initiating critical tasks such as tissue cutting. Segmenting endoscopic video is a challenging problem due to a variety of complications including significant noise attributed to bleeding and smoke from cutting, poor appearance contrast between different tissue types, occluding surgical tools, and limited visibility of the objects' geometries on the projected camera views. In this paper, we propose a multi-modal approach to segmentation where preoperative 3D computed tomography scans and intraoperative stereo-endoscopic video data are jointly analyzed. The idea is to segment multiple poorly visible structures in the stereo/multichannel endoscopic videos by fusing reliable prior knowledge captured from the preoperative 3D scans. More specifically, we estimate and track the pose of the preoperative models in 3D and consider the models' non-rigid deformations to match with corresponding visual cues in multi-channel endoscopic video and segment the objects of interest. Further, contrary to most augmented reality frameworks in endoscopic surgery that assume known camera parameters, an assumption that is often violated during surgery due to non-optimal camera calibration and changes in camera focus/zoom, our method embeds these parameters into the optimization hence correcting the calibration parameters within the segmentation process. We evaluate our technique on synthetic data, ex vivo lamb kidney datasets, and in vivo clinical partial nephrectomy surgery with results demonstrating high accuracy and robustness.

  14. Risks to human health and estuarine ecology posed by pulling out creosote-treated timber on oyster farms.

    Science.gov (United States)

    Smith, Paul T

    2008-01-31

    Five oyster farms in Port Stephens, Australia were studied to identify consequences of using creosote-treated posts and the risks posed by removing the posts. Gas chromatography coupled with mass spectrometry (GC/MS) was used to measure polycyclic aromatic hydrocarbons (PAHs) and phenols in sediments, timber, water and oyster tissue. Before posts were removed, the total PAHs in surface sediment on farms was 24.1 mgkg(-1) dry weight. This increased to 45.5 mgkg(-1) dry weight after the posts were pulled out and remained significantly higher 6 months later at 59.7 mgkg(-1) dry weight. A similar increase was found in deeper sediments. The sediment attached to creosote-treated posts had a total concentration of PAHs of 484-2642 mgkg(-1) dry weight, while the corresponding value for the sediment on tar-treated posts was only 30.7 mgkg(-1) dry weight. The surface timber of creosote-treated posts had high levels of PAHs and an average post contained 43 g of PAHs. The total PAHs dispersed to the environment when a creosote-treated post was pulled out was at least 0.67 g. The main species were PAHs with low-molecular weights: fluoranthene, phenanthrene, pyrene, acenaphthylene and chrysene. Benzo(a)pyrene represented 1-10% of PAHs in most samples. Bioassays with creosote-contaminated sediment revealed that Sydney rock oysters (Saccostrea glomerate) and Pacific oysters (Crassostrea gigas) accumulated PAHs at (mgkg(-1) wet tissue weight): 11.3-15.3 and 35.5-47.9, respectively, when exposed for 5 days to water with contaminants needs to be managed in light of risks to human health and estuarine ecology.

  15. Automatic pose initialization for accurate 2D/3D registration applied to abdominal aortic aneurysm endovascular repair

    Science.gov (United States)

    Miao, Shun; Lucas, Joseph; Liao, Rui

    2012-02-01

    Minimally invasive abdominal aortic aneurysm (AAA) stenting can be greatly facilitated by overlaying the preoperative 3-D model of the abdominal aorta onto the intra-operative 2-D X-ray images. Accurate 2-D/3-D registration in 3-D space makes the 2-D/3-D overlay robust to the change of C-Arm angulations. By far, the 2-D/3-D registration methods based on simulated X-ray projection images using multiple image planes have been shown to be able to provide satisfactory 3-D registration accuracy. However, one drawback of the intensity-based 2-D/3-D registration methods is that the similarity measure is usually highly non-convex and hence the optimizer can easily be trapped into local minima. User interaction therefore is often needed in the initialization of the position of the 3-D model in order to get a successful 2-D/3-D registration. In this paper, a novel 3-D pose initialization technique is proposed, as an extension of our previously proposed bi-plane 2-D/3-D registration method for AAA intervention [4]. The proposed method detects vessel bifurcation points and spine centerline in both 2-D and 3-D images, and utilizes landmark information to bring the 3-D volume into a 15mm capture range. The proposed landmark detection method was validated on real dataset, and is shown to be able to provide a good initialization for 2-D/3-D registration in [4], thus making the workflow fully automatic.

  16. Pose Estimation of a Mobile Robot Based on Fusion of IMU Data and Vision Data Using an Extended Kalman Filter.

    Science.gov (United States)

    Alatise, Mary B; Hancke, Gerhard P

    2017-09-21

    Using a single sensor to determine the pose estimation of a device cannot give accurate results. This paper presents a fusion of an inertial sensor of six degrees of freedom (6-DoF) which comprises the 3-axis of an accelerometer and the 3-axis of a gyroscope, and a vision to determine a low-cost and accurate position for an autonomous mobile robot. For vision, a monocular vision-based object detection algorithm speeded-up robust feature (SURF) and random sample consensus (RANSAC) algorithms were integrated and used to recognize a sample object in several images taken. As against the conventional method that depend on point-tracking, RANSAC uses an iterative method to estimate the parameters of a mathematical model from a set of captured data which contains outliers. With SURF and RANSAC, improved accuracy is certain; this is because of their ability to find interest points (features) under different viewing conditions using a Hessain matrix. This approach is proposed because of its simple implementation, low cost, and improved accuracy. With an extended Kalman filter (EKF), data from inertial sensors and a camera were fused to estimate the position and orientation of the mobile robot. All these sensors were mounted on the mobile robot to obtain an accurate localization. An indoor experiment was carried out to validate and evaluate the performance. Experimental results show that the proposed method is fast in computation, reliable and robust, and can be considered for practical applications. The performance of the experiments was verified by the ground truth data and root mean square errors (RMSEs).

  17. Pose Estimation of a Mobile Robot Based on Fusion of IMU Data and Vision Data Using an Extended Kalman Filter

    Directory of Open Access Journals (Sweden)

    Mary B. Alatise

    2017-09-01

    Full Text Available Using a single sensor to determine the pose estimation of a device cannot give accurate results. This paper presents a fusion of an inertial sensor of six degrees of freedom (6-DoF which comprises the 3-axis of an accelerometer and the 3-axis of a gyroscope, and a vision to determine a low-cost and accurate position for an autonomous mobile robot. For vision, a monocular vision-based object detection algorithm speeded-up robust feature (SURF and random sample consensus (RANSAC algorithms were integrated and used to recognize a sample object in several images taken. As against the conventional method that depend on point-tracking, RANSAC uses an iterative method to estimate the parameters of a mathematical model from a set of captured data which contains outliers. With SURF and RANSAC, improved accuracy is certain; this is because of their ability to find interest points (features under different viewing conditions using a Hessain matrix. This approach is proposed because of its simple implementation, low cost, and improved accuracy. With an extended Kalman filter (EKF, data from inertial sensors and a camera were fused to estimate the position and orientation of the mobile robot. All these sensors were mounted on the mobile robot to obtain an accurate localization. An indoor experiment was carried out to validate and evaluate the performance. Experimental results show that the proposed method is fast in computation, reliable and robust, and can be considered for practical applications. The performance of the experiments was verified by the ground truth data and root mean square errors (RMSEs.

  18. The present global financial and economic crisis poses an additional risk factor for mental health problems on the employees.

    Science.gov (United States)

    Avčin, Bojana Avguštin; Kučina, Andrea Užmah; Sarotar, Brigita Novak; Radovanović, Mirjana; Plesničar, Blanka Kores

    2011-09-01

    The global financial and economic crisis starting in 2007 led to a deterioration of several socio-economic determinants of mental health. The aim of this cross-sectional study was to examine the impact of the present economic crisis on the depression and anxiety levels of the employed in the private and public sector in Slovenia. Altogether 1592 employees completed an internet based self-reported questionnaire. Data about perceived impact of the economic crisis, several socio-demographic, socioeconomic, and health parameters were collected. Depression symptoms were assessed by the Center for Epidemiological Studies-Depression Scale and anxiety symptoms by the Spielberger State-Inventory. Regression models were used 1) to explore the associations of the economic crisis with the level of depression and anxiety symptoms while controlling for some sociodemographic and work characteristic variables, and 2) to understand the relationship between some potentially important socioeconomic variables and the perception of the economic crisis. Depressive and anxiety scores were significantly increased among 590 (46.6%) employees being affected by the economic crisis. The level of depressive symptoms was significantly associated with perceived impact by the crisis, recent sick leave, reported injuries sustained at work, benzodiazepine and analgesic use, the lack of emotional support, and trust in crisis telephone lines. The level of anxiety symptoms yielded the robust association with the level of depression symptoms, reported injuries sustained on the way to work and education. The economic crisis poses an additional risk factor for mental health problems which clinicians should internalize and become more aware of them. Symptoms of depression and anxiety can be masked in high-utilizers of medical care with physical complaints or psychoactive drug use.

  19. Risks to Ecological Receptors Posed by Contaminants of Potential Concern in the Lower Three Runs Cooling Ponds and Canals

    Energy Technology Data Exchange (ETDEWEB)

    Paller, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Blas, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-03-21

    The upper portion of Lower Three Runs includes several ponds, reservoirs, and canals that were formerly used as a cooling system for nuclear production reactors. This area was divided into nine exposure areas (EAs) for the assessment of environmental contamination resulting from past reactor operations and other industrial processes. A tiered screening process identified several contaminants of potential concern including aluminum, cyanide, lead, manganese, mercury, DDD, DDE, and DDT. Risks posed by these contaminants to ecological receptors (river otter, belted kingfisher, raccoon, and blue heron) were assessed using contaminant exposure models that estimated contaminant intake resulting from ingestion of food, water, and sediment/ soil and compared these intakes with toxicity reference values (TRVs). The contaminant exposure models showed that the TRVs were not exceeded in the otter model, exceeded by aluminum in EA 7 (Pond 2 and associated canals) in the raccoon model, and exceeded by mercury in EAs 2, 3 (Pond B), 6 (Par Pond), and 8 (Ponds 4 and 5 and Canal to Pond C) in both the kingfisher and blue heron models. Hazard quotients (total exposure dose divided by the TRV) were 2.8 for aluminum and 1.7- 3.6 for mercury. The primary route of exposure for aluminum was the ingestion of soil, and the primary route of exposure for mercury was the ingestion of mercury contaminated fish. Elevated levels of mercury in fish were at least partly the result of the aerial deposition of mercury onto Lower Three Runs and its watershed. The atmospheric deposition of mercury creates pervasive contamination in fish throughout the Savannah River basin. Another possible source of mercury was the discharge of mercury contaminated Savannah River water into the Lower Three Runs cooling ponds and canals during previous years of reactor operation. This contamination originated from industries located upstream of the SRS. The aluminum exceedance for the raccoon was likely the result of

  20. Limitations and opportunities for Permian-Triassic carbonate-carbon isotope stratigraphy posed by microbial-controlled diagenetic mineral additions

    Science.gov (United States)

    Schobben, Martin; van de Velde, Sebastiaan; Suchocka, Jana; Leda, Lucyna; Korn, Dieter; Struck, Ulrich; Vinzenz Ullmann, Clemens; Hairapetian, Vachik; Ghaderi, Abbas; Korte, Christoph; Newton, Robert J.; Poulton, Simon W.; Wignall, Paul B.

    2017-04-01

    Bulk-carbonate stable carbon isotope records are used to proxy the ancient biogeochemical carbon cycle as well as aid in determining the age of sedimentary deposits. However, the multicomponent nature and the component-specific diagenetic potential of bulk-rock pose limits on the applicability of this proxy in recording ancient seawater chemistry and its usability as a stratigraphic aid. The aim of this study is to disentangle primary trends from diagenetic signals in carbonate-carbon isotope records traversing the Permian-Triassic boundary in marine carbonate-bearing sequences of Iran and South China. We observe, 1) a global first-order trend towards depleted carbon isotope values across the Permian-Triassic transition, 2) second-order carbon isotope variability superimposed on the first-order trend, and 3) a temporal trend in the amplitude of the second-order carbon isotope fluctuations. By application of a diagenetic model, we show that microbial-steered carbonate additions can introduce diagenetic carbon isotope signals to the carbonate archive. Organic carbon sedimentation has the potential to fuel this (sub)seafloor microbial pathway of carbonate stabilization and determines trajectories of diagenetic bulk-rock carbon isotope alteration. Moreover, we identified through this numerical exercise that lowered marine sulfate levels makes the sedimentary system vulnerable to diagenetic modulations of the primary carbon isotope signal, by modest changes of organic carbon supply. This approach suggests that latest Permian reduced bioturbation, consequential heterogeneous organic matter accumulation and authigenic mineralization can explain the temporal trend of increased second-order carbon isotope scatter, whilst retaining the first-order trend. In conclusion, the combined dataset and calculations suggest that the application of carbon isotope chemostratigraphy of the Permian-Triassic boundary is at present limited to the recognition of broad temporal patterns

  1. Long-term day-and-night rotating shift work poses a barrier to the normalization of alanine transaminase.

    Science.gov (United States)

    Lin, Yu-Cheng; Hsieh, I-Chun; Chen, Pau-Chung

    2014-05-01

    . These observations demonstrate that persistent day-and-night RSW pose a vigorous obstacle to the normalization of e-ALT among workers with preexisting abnormal liver function. We suggest that workers and managers approach with caution the consideration of assigning or accepting long-term day-and-night RSW when an employee health screening shows evidence of abnormal liver function.

  2. Elucidating challenges that electronic cigarettes pose to tobacco control in Asia: a population-based national survey in Taiwan.

    Science.gov (United States)

    Chang, Hui-Chin; Tsai, Yi-Wen; Shiu, Ming-Neng; Wang, Ying-Ting; Chang, Po-Yin

    2017-03-27

    This study investigated the prevalence and correlates of electronic cigarettes (e-cigarettes) use in Taiwan. We studied a nationally representative random sample in the 2015 Taiwan Adult Smoking Behavior Survey. This study included 26 021 participants aged 15 years or older (51% women, 79% non-smokers, 16% aged 15-24 years), after excluding 31 persons (0.1%) who had missing information on e-cigarette use. The prevalence of ever having used e-cigarettes was calculated in the overall sample and by smoking status (current, former and never) or age (15-24, 25-44 and ≥45 years). We performed multivariable log-binomial regression to assess correlates of ever having used e-cigarettes among all participants and separately for subgroups by smoking status and age. Approximately 3% of all participants had ever used e-cigarettes. The prevalence of ever having used e-cigarettes was high in current smokers (14%) and people aged 18-24 years (7%). E-cigarette use was particularly common in people aged 15-24 years who were current (49-52%) or former (22-39%) smokers. Ever having used e-cigarettes was positively associated with tobacco smoking (adjusted prevalence ratio (aPR): 21.5, 95% CI 15.4 to 29.8, current smokers; aPR: 8.3, 95% CI 15.2 to 13.1, former smokers), younger age and high socioeconomic status. Age remained a significant factor of ever having used e-cigarettes across smoking status groups. Among non-smokers, men had a 2.4-fold (95% CI 1.5 to 3.8) greater prevalence of e-cigarette use than women. E-cigarette use was uncommon in the general population in Taiwan, but prevalence was high among smokers and young people. This study highlights challenges that e-cigarettes pose to tobacco control, which warrant high priority action by policymakers and public health professionals. E-cigarette regulations should focus on young people. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  3. How To Deal with Multiple Binding Poses in Alchemical Relative Protein–Ligand Binding Free Energy Calculations

    Science.gov (United States)

    2016-01-01

    Recent advances in improved force fields and sampling methods have made it possible for the accurate calculation of protein–ligand binding free energies. Alchemical free energy perturbation (FEP) using an explicit solvent model is one of the most rigorous methods to calculate relative binding free energies. However, for cases where there are high energy barriers separating the relevant conformations that are important for ligand binding, the calculated free energy may depend on the initial conformation used in the simulation due to the lack of complete sampling of all the important regions in phase space. This is particularly true for ligands with multiple possible binding modes separated by high energy barriers, making it difficult to sample all relevant binding modes even with modern enhanced sampling methods. In this paper, we apply a previously developed method that provides a corrected binding free energy for ligands with multiple binding modes by combining the free energy results from multiple alchemical FEP calculations starting from all enumerated poses, and the results are compared with Glide docking and MM-GBSA calculations. From these calculations, the dominant ligand binding mode can also be predicted. We apply this method to a series of ligands that bind to c-Jun N-terminal kinase-1 (JNK1) and obtain improved free energy results. The dominant ligand binding modes predicted by this method agree with the available crystallography, while both Glide docking and MM-GBSA calculations incorrectly predict the binding modes for some ligands. The method also helps separate the force field error from the ligand sampling error, such that deviations in the predicted binding free energy from the experimental values likely indicate possible inaccuracies in the force field. An error in the force field for a subset of the ligands studied was identified using this method, and improved free energy results were obtained by correcting the partial charges assigned to the

  4. How to deal with multiple binding poses in alchemical relative protein-ligand binding free energy calculations.

    Science.gov (United States)

    Kaus, Joseph W; Harder, Edward; Lin, Teng; Abel, Robert; McCammon, J Andrew; Wang, Lingle

    2015-06-09

    Recent advances in improved force fields and sampling methods have made it possible for the accurate calculation of protein–ligand binding free energies. Alchemical free energy perturbation (FEP) using an explicit solvent model is one of the most rigorous methods to calculate relative binding free energies. However, for cases where there are high energy barriers separating the relevant conformations that are important for ligand binding, the calculated free energy may depend on the initial conformation used in the simulation due to the lack of complete sampling of all the important regions in phase space. This is particularly true for ligands with multiple possible binding modes separated by high energy barriers, making it difficult to sample all relevant binding modes even with modern enhanced sampling methods. In this paper, we apply a previously developed method that provides a corrected binding free energy for ligands with multiple binding modes by combining the free energy results from multiple alchemical FEP calculations starting from all enumerated poses, and the results are compared with Glide docking and MM-GBSA calculations. From these calculations, the dominant ligand binding mode can also be predicted. We apply this method to a series of ligands that bind to c-Jun N-terminal kinase-1 (JNK1) and obtain improved free energy results. The dominant ligand binding modes predicted by this method agree with the available crystallography, while both Glide docking and MM-GBSA calculations incorrectly predict the binding modes for some ligands. The method also helps separate the force field error from the ligand sampling error, such that deviations in the predicted binding free energy from the experimental values likely indicate possible inaccuracies in the force field. An error in the force field for a subset of the ligands studied was identified using this method, and improved free energy results were obtained by correcting the partial charges assigned to the

  5. Chlorophenols in marine organisms from the southern coast of Hangzhou Bay, China, and an assessment of risks posed to human health

    Science.gov (United States)

    Zheng, Dan; Jiao, Haifeng; Zhong, Huiying; Qiu, Jishi; Yan, Xiaojun; Duan, Qingyuan; Chai, Liyue

    2017-06-01

    The composition of chlorophenols in marine organisms from the southern coast of Hangzhou Bay, China, was analyzed and the health risks posed to humans assessed. A total of 19 chlorophenols from 16 types of marine organism were analyzed across nine survey sections in Hangzhou Bay. The chlorophenols were analyzed by gas chromatography-mass spectrometry using a DB-5MS quartz capillary column. The concentrations of monochlorophenol, dichlorophenol, trichlorophenol, tetrachlorophenol, and pentachlorophenol ranged from below the detection limit (ND) to 132 μg/kg, ND-51.0 μg/kg, ND-42.5 μg/kg, ND-69.0 μg/kg, and ND-9.06 μg/kg, respectively. Additionally, concentration differences between each type of chlorophenol were not signifi cant (P>0.05). However, signifi cant differences were found between monochlorophenol (F=8.13, Prisk indices were risk was posed by 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, 2,4,5-trichlorophenol, 2,3,4,6-tetrachlorophenol, and pentachlorophenol to humans consuming marine organisms from the study area. Furthermore, the carcinogenic risks posed by 2,4,6-trichlorophenol and pentachlorophenol were lower than limits set by the International Commission on Radiological Protection and the US Environmental Protection Agency. However, the noncarcinogenic and carcinogenic risks posed by chlorophenols in marine organisms from four of the survey sections (Sizaopu, Niluoshan, Longshan Town and Xinhong zha) were higher than the other survey sections.

  6. A Method for Improving the Pose Accuracy of a Robot Manipulator Based on Multi-Sensor Combined Measurement and Data Fusion

    Directory of Open Access Journals (Sweden)

    Bailing Liu

    2015-04-01

    Full Text Available An improvement method for the pose accuracy of a robot manipulator by using a multiple-sensor combination measuring system (MCMS is presented. It is composed of a visual sensor, an angle sensor and a series robot. The visual sensor is utilized to measure the position of the manipulator in real time, and the angle sensor is rigidly attached to the manipulator to obtain its orientation. Due to the higher accuracy of the multi-sensor, two efficient data fusion approaches, the Kalman filter (KF and multi-sensor optimal information fusion algorithm (MOIFA, are used to fuse the position and orientation of the manipulator. The simulation and experimental results show that the pose accuracy of the robot manipulator is improved dramatically by 38%~78% with the multi-sensor data fusion. Comparing with reported pose accuracy improvement methods, the primary advantage of this method is that it does not require the complex solution of the kinematics parameter equations, increase of the motion constraints and the complicated procedures of the traditional vision-based methods. It makes the robot processing more autonomous and accurate. To improve the reliability and accuracy of the pose measurements of MCMS, the visual sensor repeatability is experimentally studied. An optimal range of 1 x 0.8 x 1 ~ 2 x 0.8 x 1  m in the field of view (FOV is indicated by the experimental results.

  7. Potential Threats Posed by New or Emerging Marine Biotoxins in UK Waters and Examination of Detection Methodology Used in Their Control: Brevetoxins

    Directory of Open Access Journals (Sweden)

    Andrew D. Turner

    2015-03-01

    Full Text Available Regular occurrence of brevetoxin-producing toxic phytoplankton in commercial shellfishery areas poses a significant risk to shellfish consumer health. Brevetoxins and their causative toxic phytoplankton are more limited in their global distribution than most marine toxins impacting commercial shellfisheries. On the other hand, trends in climate change could conceivably lead to increased risk posed by these toxins in UK waters. A request was made by UK food safety authorities to examine these toxins more closely to aid possible management strategies, should they pose a threat in the future. At the time of writing, brevetoxins have been detected in the Gulf of Mexico, the Southeast US coast and in New Zealand waters, where regulatory levels for brevetoxins in shellfish have existed for some time. This paper reviews evidence concerning the prevalence of brevetoxins and brevetoxin-producing phytoplankton in the UK, together with testing methodologies. Chemical, biological and biomolecular methods are reviewed, including recommendations for further work to enable effective testing. Although the focus here is on the UK, from a strategic standpoint many of the topics discussed will also be of interest in other parts of the world since new and emerging marine biotoxins are of global concern.

  8. Self-Management of Patient Body Position, Pose, and Motion Using Wide-Field, Real-Time Optical Measurement Feedback: Results of a Volunteer Study

    Energy Technology Data Exchange (ETDEWEB)

    Parkhurst, James M. [Developing Technologies, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester (United Kingdom); Price, Gareth J., E-mail: gareth.price@christie.nhs.uk [Developing Technologies, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester (United Kingdom); Faculty of Medical and Human Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester (United Kingdom); Sharrock, Phil J. [Developing Technologies, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester (United Kingdom); Jackson, Andrew S.N. [Clinical Oncology, Southampton University Hospitals Foundation Trust, Southampton (United Kingdom); Stratford, Julie [Department of Radiotherapy, The Christie NHS Foundation Trust, Manchester (United Kingdom); Moore, Christopher J. [Developing Technologies, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester (United Kingdom); Faculty of Medical and Human Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester (United Kingdom)

    2013-12-01

    Purpose: We present the results of a clinical feasibility study, performed in 10 healthy volunteers undergoing a simulated treatment over 3 sessions, to investigate the use of a wide-field visual feedback technique intended to help patients control their pose while reducing motion during radiation therapy treatment. Methods and Materials: An optical surface sensor is used to capture wide-area measurements of a subject's body surface with visualizations of these data displayed back to them in real time. In this study we hypothesize that this active feedback mechanism will enable patients to control their motion and help them maintain their setup pose and position. A capability hierarchy of 3 different level-of-detail abstractions of the measured surface data is systematically compared. Results: Use of the device enabled volunteers to increase their conformance to a reference surface, as measured by decreased variability across their body surfaces. The use of visual feedback also enabled volunteers to reduce their respiratory motion amplitude to 1.7 ± 0.6 mm compared with 2.7 ± 1.4 mm without visual feedback. Conclusions: The use of live feedback of their optically measured body surfaces enabled a set of volunteers to better manage their pose and motion when compared with free breathing. The method is suitable to be taken forward to patient studies.

  9. Retrospective Validation of a Structure-Based Virtual Screening Protocol to Identify Ligands for Estrogen Receptor Alpha and Its Application to Identify the Alpha-Mangostin Binding Pose

    Directory of Open Access Journals (Sweden)

    Agustina Setiawati

    2014-07-01

    Full Text Available The publicly available enhanced data of ligands and decoys for estrogen receptor alpha (ERα which were recently published has made the retrospective validation of a structure-based virtual screening (SBVS protocol to identify ligands for ERα possible. In this article, we present the retrospective validation of an SBVS protocol using PLANTS molecular docking software version 1.2 (PLANTS1.2 as the backbone software. The protocol shows better enrichment factor at 1% false positives (EF1% value and the Area Under Curve (AUC value of the Receiver Operator Characteristic (ROC compared to the original published protocol. Moreover, in all 1000 iterative attempts the protocol could reproduce the co-crystal pose of 4-hydroxitamoxifen in ERα binding pocket. It shows that the protocol is not only able to identify potent ligands for ERα but also able to be employed in examining binding pose of known ligand. Thence, the protocol was successfully employed to examine the binding poses of α-mangostin, an ERα ligand found in the Garcinia mangostana, L. pericarp.

  10. The effect of risk perception on public preferences and willingness to pay for reductions in the health risks posed by toxic cyanobacterial blooms.

    Science.gov (United States)

    Hunter, Peter D; Hanley, Nick; Czajkowski, Mikołaj; Mearns, Kathryn; Tyler, Andrew N; Carvalho, Laurence; Codd, Geoffrey A

    2012-06-01

    Mass populations of toxin-producing cyanobacteria are an increasingly common occurrence in inland and coastal waters used for recreational purposes. These mass populations pose serious risks to human and animal health and impose potentially significant economic costs on society. In this study, we used contingent valuation (CV) methods to elicit public willingness to pay (WTP) for reductions in the morbidity risks posed by blooms of toxin-producing cyanobacteria in Loch Leven, Scotland. We found that 55% of respondents (68% excluding protest voters) were willing to pay for a reduction in the number of days per year (from 90, to either 45 or 0 days) that cyanobacteria pose a risk to human health at Loch Leven. The mean WTP for a risk reduction was UK£9.99-12.23/household/year estimated using a logistic spike model. In addition, using the spike model and a simultaneous equations model to control for endogeneity bias, we found the respondents' WTP was strongly dependent on socio-demographic characteristics, economic status and usage of the waterbody, but also individual-specific attitudes and perceptions towards health risks. This study demonstrates that anticipated health risk reductions are an important nonmarket benefit of improving water quality in recreational waters and should be accounted for in future cost-benefit analyses such as those being undertaken under the auspices of the European Union's Water Framework Directive, but also that such values depend on subjective perceptions of water-related health risks and general attitudes towards the environment. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Sustained employability of workers in a production environment: design of a stepped wedge trial to evaluate effectiveness and cost-benefit of the POSE program

    Directory of Open Access Journals (Sweden)

    van Holland Berry J

    2012-11-01

    Full Text Available Abstract Background Sustained employability and health are generating awareness of employers in an aging and more complex work force. To meet these needs, employers may offer their employees health surveillance programs, to increase opportunities to work on health and sustained employability. However, evidence for these health surveillance programs is lacking. The FLESH study (Functional Labour Evaluation for Sustained Health and employment was developed to evaluate a comprehensive workers’ health promotion program on its effectiveness, cost-benefit, and process of the intervention. Methods The study is designed as a cluster randomised stepped wedge trial with randomisation at company plant level and is carried out in a large meat processing company. Every contracted employee is offered the opportunity to participate in the POSE program (Promotion Of Sustained Employability. The main goals of the POSE program are 1 providing employee’s insight into their current employability and health status, 2 offering opportunities to improve employability and decrease health risks and 3 improving employability and health sustainably in order to keep them healthy at work. The program consists of a broad assessment followed by a counselling session and, if needed, a tailored intervention. Measurements will be performed at baseline and will be followed up at 20, 40, 60, 80, 106 and 132 weeks. The primary outcome measures are work ability, productivity and absenteeism. Secondary outcomes include health status, vitality, and psychosocial workload. A cost-benefit study will be conducted from the employers’ perspective. A process evaluation will be conducted and the satisfaction of employer and employees with the program will be assessed. Discussion This study provides information on the effectiveness of the POSE program on sustained employment. When the program proves to be effective, employees benefit by improved work ability, and health. Employers benefit

  12. The analysis and reconstruction of cult psychosomatic training poses of Trypilska Culture in sitting positions on the low-seats with legs apart.

    Directory of Open Access Journals (Sweden)

    Tverdokhlib O.F.

    2011-04-01

    Full Text Available The research purpose - to reconstruct Trypilska Culture cult psychosomatic training poses in sitting positions on the low-seats with legs apart. The research objects selection was formed by the photographic images of anthropomorphous figures, which are displayed in the museums, private collections, scientific publishments. It is educed, that in fifteen static sitting positions on the low-seats with legs apart practiced Trypilska Culture cult psychosomatic training by young and middle-age disproportional middle and strong built nude different sex adepts whose bodies were decorated.

  13. Piecewise-rigid 2D-3D registration for pose estimation of snake-like manipulator using an intraoperative x-ray projection

    Science.gov (United States)

    Otake, Y.; Murphy, R. J.; Kutzer, M. D.; Taylor, R. H.; Armand, M.

    2014-03-01

    Background: Snake-like dexterous manipulators may offer significant advantages in minimally-invasive surgery in areas not reachable with conventional tools. Precise control of a wire-driven manipulator is challenging due to factors such as cable deformation, unknown internal (cable friction) and external forces, thus requiring correcting the calibration intraoperatively by determining the actual pose of the manipulator. Method: A method for simultaneously estimating pose and kinematic configuration of a piecewise-rigid object such as a snake-like manipulator from a single x-ray projection is presented. The method parameterizes kinematics using a small number of variables (e.g., 5), and optimizes them simultaneously with the 6 degree-of-freedom pose parameter of the base link using an image similarity between digitally reconstructed radiographs (DRRs) of the manipulator's attenuation model and the real x-ray projection. Result: Simulation studies assumed various geometric magnifications (1.2-2.6) and out-of-plane angulations (0°-90°) in a scenario of hip osteolysis treatment, which demonstrated the median joint angle error was 0.04° (for 2.0 magnification, +/-10° out-of-plane rotation). Average computation time was 57.6 sec with 82,953 function evaluations on a mid-range GPU. The joint angle error remained lower than 0.07° while out-of-plane rotation was 0°-60°. An experiment using video images of a real manipulator demonstrated a similar trend as the simulation study except for slightly larger error around the tip attributed to accumulation of errors induced by deformation around each joint not modeled with a simple pin joint. Conclusions: The proposed approach enables high precision tracking of a piecewise-rigid object (i.e., a series of connected rigid structures) using a single projection image by incorporating prior knowledge about the shape and kinematic behavior of the object (e.g., each rigid structure connected by a pin joint parameterized by a

  14. Sustained employability of workers in a production environment: design of a stepped wedge trial to evaluate effectiveness and cost-benefit of the POSE program.

    Science.gov (United States)

    van Holland, Berry J; de Boer, Michiel R; Brouwer, Sandra; Soer, Remko; Reneman, Michiel F

    2012-11-20

    Sustained employability and health are generating awareness of employers in an aging and more complex work force. To meet these needs, employers may offer their employees health surveillance programs, to increase opportunities to work on health and sustained employability. However, evidence for these health surveillance programs is lacking. The FLESH study (Functional Labour Evaluation for Sustained Health and employment) was developed to evaluate a comprehensive workers' health promotion program on its effectiveness, cost-benefit, and process of the intervention. The study is designed as a cluster randomised stepped wedge trial with randomisation at company plant level and is carried out in a large meat processing company. Every contracted employee is offered the opportunity to participate in the POSE program (Promotion Of Sustained Employability). The main goals of the POSE program are 1) providing employee's insight into their current employability and health status, 2) offering opportunities to improve employability and decrease health risks and 3) improving employability and health sustainably in order to keep them healthy at work. The program consists of a broad assessment followed by a counselling session and, if needed, a tailored intervention. Measurements will be performed at baseline and will be followed up at 20, 40, 60, 80, 106 and 132 weeks. The primary outcome measures are work ability, productivity and absenteeism. Secondary outcomes include health status, vitality, and psychosocial workload. A cost-benefit study will be conducted from the employers' perspective. A process evaluation will be conducted and the satisfaction of employer and employees with the program will be assessed. This study provides information on the effectiveness of the POSE program on sustained employment. When the program proves to be effective, employees benefit by improved work ability, and health. Employers benefit from healthier employees, reduced sick leave (costs) and

  15. Hazard posed by metals and As in PM2.5 in air of five megacities in the Beijing-Tianjin-Hebei region of China during APEC.

    Science.gov (United States)

    Zhang, Linlin; Jin, Xiaowei; Johnson, Andrew C; Giesy, John P

    2016-09-01

    Airborne fine particulate matter (PM2.5) from five megacities including Beijing, Tianjin, Shijiazhuang, Baoding, and Jinan were collected during November 2014 and compared with similar periods in 2012 and 2013. The November 2014 period coincided with the Asia Pacific Economic Cooperation (APEC) Leaders Meeting during which measures to control pollution of the air were introduced. Concentrations of 11 elements in PM2.5 were quantified by inductively coupled plasma-mass spectrometry (ICP-MS) after microwave-assisted digestion. Potential effects of five toxic trace metals including Mn, Ni, Cu, Zn, Pb, and the metalloid As on health were assessed. In 2014, concentrations of PM2.5 were significantly less than during the same period in 2012 and 2013. Mean concentrations of six elements ranked in decreasing order, Zn > Pb > Cu ≈ Mn > As > Ni, and spatial concentrations ranked in decreasing order, Shijiazhuang > Baoding > Tianjin > Jinan > Beijing. Risks of the five metals and the metalloid As to health of humans were small, except for Mn in Shijiazhuang. Risks to health posed by other elements were less during the period of study. Risks posed by the five metals and As in Beijing were greater to varying degrees after the APEC meeting. Risks to health of humans during the APEC were overall lesser than the same period in 2012 and 2013, mostly due to lesser emissions due to the short-term control measures.

  16. 3D pre- versus post-season comparisons of surface and relative pose of the corpus callosum in contact sport athletes

    Science.gov (United States)

    Lao, Yi; Gajawelli, Niharika; Haas, Lauren; Wilkins, Bryce; Hwang, Darryl; Tsao, Sinchai; Wang, Yalin; Law, Meng; Leporé, Natasha

    2014-03-01

    Mild traumatic brain injury (MTBI) or concussive injury affects 1.7 million Americans annually, of which 300,000 are due to recreational activities and contact sports, such as football, rugby, and boxing[1]. Finding the neuroanatomical correlates of brain TBI non-invasively and precisely is crucial for diagnosis and prognosis. Several studies have shown the in influence of traumatic brain injury (TBI) on the integrity of brain WM [2-4]. The vast majority of these works focus on athletes with diagnosed concussions. However, in contact sports, athletes are subjected to repeated hits to the head throughout the season, and we hypothesize that these have an influence on white matter integrity. In particular, the corpus callosum (CC), as a small structure connecting the brain hemispheres, may be particularly affected by torques generated by collisions, even in the absence of full blown concussions. Here, we use a combined surface-based morphometry and relative pose analyses, applying on the point distribution model (PDM) of the CC, to investigate TBI related brain structural changes between 9 pre-season and 9 post-season contact sport athlete MRIs. All the data are fed into surface based morphometry analysis and relative pose analysis. The former looks at surface area and thickness changes between the two groups, while the latter consists of detecting the relative translation, rotation and scale between them.

  17. Multiple receptor conformation docking, dock pose clustering and 3D QSAR studies on human poly(ADP-ribose) polymerase-1 (PARP-1) inhibitors.

    Science.gov (United States)

    Fatima, Sabiha; Jatavath, Mohan Babu; Bathini, Raju; Sivan, Sree Kanth; Manga, Vijjulatha

    2014-10-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) functions as a DNA damage sensor and signaling molecule. It plays a vital role in the repair of DNA strand breaks induced by radiation and chemotherapeutic drugs; inhibitors of this enzyme have the potential to improve cancer chemotherapy or radiotherapy. Three-dimensional quantitative structure activity relationship (3D QSAR) models were developed using comparative molecular field analysis, comparative molecular similarity indices analysis and docking studies. A set of 88 molecules were docked into the active site of six X-ray crystal structures of poly(ADP-ribose)polymerase-1 (PARP-1), by a procedure called multiple receptor conformation docking (MRCD), in order to improve the 3D QSAR models through the analysis of binding conformations. The docked poses were clustered to obtain the best receptor binding conformation. These dock poses from clustering were used for 3D QSAR analysis. Based on MRCD and QSAR information, some key features have been identified that explain the observed variance in the activity. Two receptor-based QSAR models were generated; these models showed good internal and external statistical reliability that is evident from the [Formula: see text], [Formula: see text] and [Formula: see text]. The identified key features enabled us to design new PARP-1 inhibitors.

  18. Retrieval of LAI and leaf chlorophyll content from remote sensing data by agronomy mechanism knowledge to solve the ill-posed inverse problem

    Science.gov (United States)

    Li, Zhenhai; Nie, Chenwei; Yang, Guijun; Xu, Xingang; Jin, Xiuliang; Gu, Xiaohe

    2014-10-01

    Leaf area index (LAI) and LCC, as the two most important crop growth variables, are major considerations in management decisions, agricultural planning and policy making. Estimation of canopy biophysical variables from remote sensing data was investigated using a radiative transfer model. However, the ill-posed problem is unavoidable for the unique solution of the inverse problem and the uncertainty of measurements and model assumptions. This study focused on the use of agronomy mechanism knowledge to restrict and remove the ill-posed inversion results. For this purpose, the inversion results obtained using the PROSAIL model alone (NAMK) and linked with agronomic mechanism knowledge (AMK) were compared. The results showed that AMK did not significantly improve the accuracy of LAI inversion. LAI was estimated with high accuracy, and there was no significant improvement after considering AMK. The validation results of the determination coefficient (R2) and the corresponding root mean square error (RMSE) between measured LAI and estimated LAI were 0.635 and 1.022 for NAMK, and 0.637 and 0.999 for AMK, respectively. LCC estimation was significantly improved with agronomy mechanism knowledge; the R2 and RMSE values were 0.377 and 14.495 μg cm-2 for NAMK, and 0.503 and 10.661 μg cm-2 for AMK, respectively. Results of the comparison demonstrated the need for agronomy mechanism knowledge in radiative transfer model inversion.

  19. Locally extra-optimal regularizing algorithms and a posteriori estimates of the accuracy for ill-posed problems with discontinuous solutions

    Science.gov (United States)

    Leonov, A. S.

    2016-01-01

    Local a posteriori estimates of the accuracy of approximate solutions to ill-posed inverse problems with discontinuous solutions from the classes of functions of several variables with bounded variations of the Hardy or Giusti type are studied. Unlike global estimates (in the norm), local estimates of accuracy are carried out using certain linear estimation functionals (e.g., using the mean value of the solution on a given fragment of its support). The concept of a locally extra-optimal regularizing algorithm for solving ill-posed inverse problems, which has an optimal in order local a posteriori estimate, was introduced. A method for calculating local a posteriori estimates of accuracy with the use of some distinguished classes of linear functionals for the problems with discontinuous solutions is proposed. For linear inverse problems, the method is bases on solving specialized convex optimization problems. Examples of locally extra-optimal regularizing algorithms and results of numerical experiments on a posteriori estimation of the accuracy of solutions for different linear estimation functionals are presented.

  20. Well-posed optimization problems

    CERN Document Server

    Dontchev, Asen L

    1993-01-01

    This book presents in a unified way the mathematical theory of well-posedness in optimization. The basic concepts of well-posedness and the links among them are studied, in particular Hadamard and Tykhonov well-posedness. Abstract optimization problems as well as applications to optimal control, calculus of variations and mathematical programming are considered. Both the pure and applied side of these topics are presented. The main subject is often introduced by heuristics, particular cases and examples. Complete proofs are provided. The expected knowledge of the reader does not extend beyond textbook (real and functional) analysis, some topology and differential equations and basic optimization. References are provided for more advanced topics. The book is addressed to mathematicians interested in optimization and related topics, and also to engineers, control theorists, economists and applied scientists who can find here a mathematical justification of practical procedures they encounter.

  1. Preconditioner and convergence study for the Quantum Computer Aided Design (QCAD) nonlinear poisson problem posed on the Ottawa Flat 270 design geometry.

    Energy Technology Data Exchange (ETDEWEB)

    Kalashnikova, Irina

    2012-05-01

    A numerical study aimed to evaluate different preconditioners within the Trilinos Ifpack and ML packages for the Quantum Computer Aided Design (QCAD) non-linear Poisson problem implemented within the Albany code base and posed on the Ottawa Flat 270 design geometry is performed. This study led to some new development of Albany that allows the user to select an ML preconditioner with Zoltan repartitioning based on nodal coordinates, which is summarized. Convergence of the numerical solutions computed within the QCAD computational suite with successive mesh refinement is examined in two metrics, the mean value of the solution (an L{sup 1} norm) and the field integral of the solution (L{sup 2} norm).

  2. Determination of the Geometric Form of a Plane of a Tectonic Gap as the Inverse III-posed Problem of Mathematical Physics

    Science.gov (United States)

    Sirota, Dmitry; Ivanov, Vadim

    2017-11-01

    Any mining operations influence stability of natural and technogenic massifs are the reason of emergence of the sources of differences of mechanical tension. These sources generate a quasistationary electric field with a Newtonian potential. The paper reviews the method of determining the shape and size of a flat source field with this kind of potential. This common problem meets in many fields of mining: geological exploration mineral resources, ore deposits, control of mining by underground method, determining coal self-heating source, localization of the rock crack's sources and other applied problems of practical physics. This problems are ill-posed and inverse and solved by converting to Fredholm-Uryson integral equation of the first kind. This equation will be solved by A.N. Tikhonov regularization method.

  3. An ill-posed problem for the Black-Scholes equation for a profitable forecast of prices of stock options on real market data

    Science.gov (United States)

    Klibanov, Michael V.; Kuzhuget, Andrey V.; Golubnichiy, Kirill V.

    2016-01-01

    A new empirical mathematical model for the Black-Scholes equation is proposed to forecast option prices. This model includes new interval for the price of the underlying stock, new initial and new boundary conditions. Conventional notions of maturity time and strike prices are not used. The Black-Scholes equation is solved as a parabolic equation with the reversed time, which is an ill-posed problem. Thus, a regularization method is used to solve it. To verify the validity of our model, real market data for 368 randomly selected liquid options are used. A new trading strategy is proposed. Our results indicates that our method is profitable on those options. Furthermore, it is shown that the performance of two simple extrapolation-based techniques is much worse. We conjecture that our method might lead to significant profits of those financial insitutions which trade large amounts of options. We caution, however, that further studies are necessary to verify this conjecture.

  4. Tsunami Hazard Posed to New Zealand by the Kermadec and Southern New Hebrides Subduction Margins: An Assessment Based on Plate Boundary Kinematics, Interseismic Coupling, and Historical Seismicity

    Science.gov (United States)

    Power, William; Wallace, Laura; Wang, Xiaoming; Reyners, Martin

    2012-01-01

    We assess the tsunami hazard posed to New Zealand by the Kermadec and southern New Hebrides subduction margins. Neither of these subduction zones has produced tsunami large enough to cause significant damage in New Zealand over the past 150 years of well-recorded history. However, as this time frame is short compared to the recurrence interval for major tsunamigenic earthquakes on many of the Earth's subduction zones, it should not be assumed that what has been observed so far is representative of the long term. For each of these two subduction zones we present plate kinematic and fault-locking results from block modelling of earthquake slip vector data and GPS velocities. The results are used to estimate the current rates of strain accumulation on the plate interfaces where large tsunamigenic earthquakes typically occur. We also review data on the larger historical earthquakes that have occurred on these margins, as well as the Global CMT catalogue of events since 1976. Using this information we have developed a set of scenarios for large earthquakes which have been used as initial conditions for the COMCOT tsunami code to estimate the subsequent tsunami propagation in the southwest Pacific, and from these the potential impact on New Zealand has been evaluated. Our results demonstrate that there is a significant threat posed to the Northland and Coromandel regions of New Zealand should a large earthquake ( M w ≳8.5) occur on the southern or middle regions of the Kermadec Trench, and that a similarly large earthquake on the southern New Hebrides Trench has the potential to strongly impact on the far northern parts of New Zealand close to the southern end of the submarine Three Kings Ridge. We propose logic trees for the magnitude-frequency parameters of large earthquakes originating on each trench, which are intended to form the basis for future probabilistic studies.

  5. Human health risks posed by exposure to PM10 for four life stages in a low socio-economic community in South Africa.

    Science.gov (United States)

    Thabethe, Nomsa Duduzile Lina; Engelbrecht, Jacobus Christoffel; Wright, Caradee Yael; Oosthuizen, Maria Aletta

    2014-01-01

    Mine ash dumps, industries and domestic fuel use have a great impact on air quality and PM10 (particles with a diameter equal to or less than 10 μm) is a pollutant of particular concern. The objective of this study was to assess the human health risks posed by exposure to PM10 among a low socio-economic community. The Human Health Risk Assessment (HHRA) framework (i.e. hazard assessment, dose-response assessment, exposure assessment and risk characterization) was applied. PM10 concentrations were monitored for one month during winter and summer, respectively. A HHRA was conducted to assess whether the community was exposed to PM10 concentrations that may pose carcinogenic and non-carcinogenic health risks. Generally, the residents were exposed to higher concentrations of PM10 during winter than summer, resulting in a higher risk to health during winter. Results of the HHRA showed that infants were exposed to a higher dose of PM10 than the other life stages when exposed to the same concentration due to differences in inhalation rates and the ratio between inhalation and body weight. However, they were at the same risk of developing adverse effects from exposure to the same concentration of PM10 as the other life stages were exposed to, because the 'safe' dose was also higher for infants and since all life stages, in general, are similarly affected by PM unless the chemical composition of the PM is known. This study recommends that infants and children, in particular, should not be exposed to air pollution from domestic fuel burning as one positive step to try and reduce their dose.

  6. Health risks posed to infants in rural China by exposure to short- and medium-chain chlorinated paraffins in breast milk.

    Science.gov (United States)

    Xia, Dan; Gao, Li-Rong; Zheng, Ming-Hui; Li, Jing-Guang; Zhang, Lei; Wu, Yong-Ning; Qiao, Lin; Tian, Qi-Chang; Huang, Hui-Ting; Liu, Wen-Bin; Su, Gui-Jin; Liu, Guo-Rui

    2017-06-01

    Chlorinated paraffins (CPs) are complex mixtures of synthetic chemicals found widely in environmental matrices. Short-chain CPs (SCCPs) are candidate persistent organic pollutants under the Stockholm Convention. There should be great concern about human exposure to SCCPs. Data on CP concentrations in human breast milk is scarce. This is the first study in which background SCCP and medium-chain CP (MCCP) body burdens in the general rural population of China have been estimated and health risks posed to nursing infants by CPs in breast milk assessed. The concentrations of 48 SCCP and MCCP formula congeners were determined in 24 pooled human milk samples produced from 1412 individual samples from eight provinces in 2007 and 16 provinces in 2011. The samples were analyzed by comprehensive two-dimensional gas chromatography electron capture negative ionization high-resolution time-of-flight mass spectrometry. The median SCCP and MCCP concentrations were 303 and 35.7ngg -1 lipid weight, respectively, for the 2007 samples and 360 and 45.4ngg -1 lipid weight, respectively, for the 2011 samples. The C 10 and C 14 homologs were the dominant CP carbon-chain-length groups, contributing 51% and 82% of the total SCCP and MCCP concentrations, respectively. There are probably multiple CP sources to the general Chinese population and numerous exposure pathways. The median estimated daily SCCP and MCCP intakes for nursing infants were 1310 and 152ngkg -1 d -1 , respectively, in 2007 and 1520 and 212ngkg -1 d -1 , respectively, in 2011. SCCPs do not currently pose significant risks to infants in China. However, it is necessary to continuously monitor CP concentrations and health risks because CP concentrations in Chinese human breast milk are increasing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Predicting 3D pose in partially overlapped X-ray images of knee prostheses using model-based Roentgen stereophotogrammetric analysis (RSA).

    Science.gov (United States)

    Hsu, Chi-Pin; Lin, Shang-Chih; Shih, Kao-Shang; Huang, Chang-Hung; Lee, Chian-Her

    2014-12-01

    After total knee replacement, the model-based Roentgen stereophotogrammetric analysis (RSA) technique has been used to monitor the status of prosthetic wear, misalignment, and even failure. However, the overlap of the prosthetic outlines inevitably increases errors in the estimation of prosthetic poses due to the limited amount of available outlines. In the literature, quite a few studies have investigated the problems induced by the overlapped outlines, and manual adjustment is still the mainstream. This study proposes two methods to automate the image processing of overlapped outlines prior to the pose registration of prosthetic models. The outline-separated method defines the intersected points and segments the overlapped outlines. The feature-recognized method uses the point and line features of the remaining outlines to initiate registration. Overlap percentage is defined as the ratio of overlapped to non-overlapped outlines. The simulated images with five overlapping percentages are used to evaluate the robustness and accuracy of the proposed methods. Compared with non-overlapped images, overlapped images reduce the number of outlines available for model-based RSA calculation. The maximum and root mean square errors for a prosthetic outline are 0.35 and 0.04 mm, respectively. The mean translation and rotation errors are 0.11 mm and 0.18°, respectively. The errors of the model-based RSA results are increased when the overlap percentage is beyond about 9%. In conclusion, both outline-separated and feature-recognized methods can be seamlessly integrated to automate the calculation of rough registration. This can significantly increase the clinical practicability of the model-based RSA technique.

  8. Prospective elementary school teachers’ ways of making sense of mathematical problem posing (Modos en que futuros profesores de primaria dan sentido a la invención de problemas matemáticos

    Directory of Open Access Journals (Sweden)

    Olive Chapman

    2012-06-01

    Full Text Available The study tackled prospective teachers’ sense-making of mathematical problem posing and the impact of posing different contextual problems on their learning. Focus was on the generation of new problems and reformulation of given problems. Participants were 40 prospective elementary teachers. The findings provide insights into possible ways these teachers could make sense of problem posing of contextual mathematical problems and the learning afforded by posing diverse problems. Highlighted are five perspectives and nine categories of problem posing tasks to support development of proficiency in problem-posing knowledge for teaching. El estudio indagó sobre los modos en que futuros profesores de primaria dan sentido a la invención de problemas matemáticos y el impacto de plantear diferentes problemas contextualizados en su aprendizaje. El foco fue la invención de nuevos problemas y la reformulación de otros dados. Los participantes fueron 40 futuros maestros de primaria. Los resultados proporcionan elementos sobre posibles modos en que estos maestros dan sentido a la invención de problemas matemáticos y el aprendizaje que ofrece plantear diversos problemas. Se destacan cinco perspectivas y nueve categorías de tareas en la invención de problemas para apoyar el desarrollo de la competencia de plantear problemas en la enseñanza.

  9. Within-Case and Cross-Case Analyses of Questions Posed by Fifth-Grade Students Working in Small Groups to Investigate Pendulum Motion

    Science.gov (United States)

    Tisel, James Michael

    The focus of this basic qualitative research is student questions in an unstructured inquiry setting. Case and cross-case analyses were conducted (Miles and Huberman, 1984) of the questions posed by fifth grade students working in laboratory groups of size three to five students as they investigated pendulum motion. To establish the conceptual framework for the study, literature was reviewed in the areas of cognitive theory (constructivism, conceptual change, and other theories), approaches to science, and the importance of student questions in the learning process. A review of group work, related studies of student questions and activities and relevant methods of qualitative research was also undertaken. The current study occupies the relatively unique position of being about the questions students posed to each other (not the teacher) at the outset of and throughout an unstructured inquiry activity with a minimum of teacher initiation or intervention. The focus is on finding out what questions students ask, when they ask them, what categories the questions fall into in relation to possible models of the scientific method, student motivation, and what role the questions play as the students take part in an inquiry activity. Students were video and/or audio-recorded as they did the investigation. They wrote down their questions during one-minute pauses that occurred at roughly eight-minute intervals. The groups were interviewed the next day about their experience. The recordings, question sheets, and interview accounts and recordings were analyzed by the researcher. Accounts of the experience of each group were prepared, and reiterated attempts were made to classify the questions as the main themes and categories emerged. It was found that students posed their key research question (most typically related to pendulum damping effects) midway through the first half of their activity, after having first met some competence and other needs in relation to measurement

  10. Reproduction Symposium: does grazing on biosolids-treated pasture pose a pathophysiological risk associated with increased exposure to endocrine disrupting compounds?

    Science.gov (United States)

    Evans, N P; Bellingham, M; Sharpe, R M; Cotinot, C; Rhind, S M; Kyle, C; Erhard, H; Hombach-Klonisch, S; Lind, P M; Fowler, P A

    2014-08-01

    Biosolids (processed human sewage sludge), which contain low individual concentrations of an array of contaminants including heavy metals and organic pollutants such as polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), and polychlorinated dibenzodioxins/polychlorinated dibenzofurans known to cause physiological disturbances, are increasingly being used as an agricultural fertilizer. This could pose a health threat to both humans and domestic and wild animal species. This review summarizes results of a unique model, used to determine the effects of exposure to mixtures of environmentally relevant concentrations of pollutants, in sheep grazed on biosolids-treated pastures. Pasture treatment results in nonsignificant increases in environmental chemical (EC) concentrations in soil. Whereas EC concentrations were increased in some tissues of both ewes and their fetuses, concentrations were low and variable and deemed to pose little risk to consumer health. Investigation of the effects of gestational EC exposure on fetal development has highlighted a number of issues. The results indicate that gestational EC exposure can adversely affect gonadal development (males and females) and that these effects can impact testicular morphology, ovarian follicle numbers and health, and the transcriptome and proteome in adult animals. In addition, EC exposure can be associated with altered expression of GnRH, GnRH receptors, galanin receptors, and kisspeptin mRNA within the hypothalamus and pituitary gland, gonadotroph populations within the pituitary gland, and regional aberrations in thyroid morphology. In most cases, these anatomical and functional differences do not result in altered peripheral hormone concentrations or reproductive function (e.g., lambing rate), indicating physiological compensation under the conditions tested. Physiological compensation is also suggested from studies that indicate that EC effects may be greater when exposure occurs either

  11. Status of Environmental Management Initiatives to Accelerate the Reduction of Environmental Risks and Challenges Posed by the Legacy of the Cold War

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-01-01

    Fifty years of nuclear weapons production and energy research in the United States during the Cold War generated large amounts of radioactive wastes, spent nuclear fuel (SNF), excess plutonium and uranium, thousands of contaminated facilities, and contaminated soil and groundwater. During most of that half century, the Nation did not have the environmental regulatory structure or nuclear waste cleanup technologies that exist today. The result was a legacy of nuclear waste that was stored and disposed of in ways now considered unacceptable. Cleaning up and ultimately disposing of these wastes is the responsibility of the U.S. Department of Energy (DOE). In 1989, DOE established the Office of Environmental Management (EM) to solve the large scale and technically challenging risks posed by the world's largest nuclear cleanup. This required EM to build a new nuclear cleanup infrastructure, assemble and train a technically specialized workforce, and develop the technologies and tools required to safely decontaminate, disassemble, stabilize, disposition, and remediate unique radiation hazards. The sites where nuclear activities produced legacy waste and contamination include the original Manhattan Project sites--Los Alamos, New Mexico; Hanford, Washington; and Oak Ridge, Tennessee--as well as major Cold War sites, such as Savannah River Site, South Carolina; the Idaho National Laboratory, Idaho; Rocky Flats Plant, Colorado; and Fernald, Ohio. Today EM has responsibility for nuclear cleanup activities at 21 sites covering more than two million acres in 13 states, and employs more than 30,000 Federal and contractor employees, including scientists, engineers and hazardous waste technicians. This cleanup poses unique, technically complex problems, which must be solved under the most hazardous of conditions, and which will require billions of dollars a year for several more decades. The EM program focus during its first 10 years was on managing the most urgent risks and

  12. Does by-catch pose a threat for the conservation of seabird populations in the southern Ionian Sea (eastern Mediterranean? A questionnaire based survey of local fisheries

    Directory of Open Access Journals (Sweden)

    G. KARRIS

    2013-09-01

    Full Text Available A significant number of studies worldwide have shown that incidental catches (by-catch of seabirds in fishing gear might pose a considerable risk for the conservation of their populations. Nevertheless reliable data on by-catch rates of seabirds in European marine ecosystems are patchy and need to be improved. This study constitutes a first attempt at the evaluation of by-catch rates in the southern Ionian Sea. Data were obtained by distributing a specific questionnaire to the fishers of Zakynthos Island. 150 professional fishers (representing 90% of the local fishing fleet participated in the research, and were interviewed during July-December 2010. The information collected showed that commercial longline and (to a lesser extent gillnet fishery gears caused incidental catches mostly of Scopoli’s Shearwater and Mediterranean Shag. The temporal analysis of the incidental bird mortality showed that seabirds were more susceptible to be trapped in fishery gears set around sunrise during spring and summer whereas spatial analysis of by-catch data indicated variations in the number of seabirds caught in different fishery areas.

  13. Protective effect of Kalpaamruthaa in combating the oxidative stress posed by aflatoxin B1-induced hepatocellular carcinoma with special reference to flavonoid structure-activity relationship.

    Science.gov (United States)

    Umarani, Mohanasundaram; Shanthi, Palanivelu; Sachdanandam, Panchanadham

    2008-02-01

    Aflatoxin B1 (AFB1) is a potent hepatotoxic and hepatocarcinogenic mycotoxin. It has been postulated to play a major role in the aetiology of primary human liver cancer. Lipid peroxidation (LPO) is one of the main manifestations of oxidative damage and has been found to play an important role in the toxicity and carcinogenesis of many carcinogens. The present investigation aimed at assessing the effect of Kalpaamruthaa (KA), a modified Siddha preparation, on AFB1-mediated hepatocellular carcinoma (HCC). The drug was administered orally (300 mg/kg body weight/day) for 28 days to HCC-bearing rats. The level of lipid peroxides, antioxidant enzymes, glutathione and glutathione-metabolizing enzyme activity were determined in the plasma, haemolysate and liver homogenate of control and experimental rats. Rats subjected to AFB1showed a decline in the thiol capacity of the cell, accompanied by high malondialdehyde levels along with lowered activities of enzymic and non-enzymic antioxidant and glutathione-metabolizing enzyme levels. KA treatment restored the deranged LPO and enzyme activities almost to control levels, thereby suggesting hepatoprotection. This study highlighted the beneficial effect of KA in reversing the damage posed by AFB1 and thereby bringing about an improvement in the antioxidant status to combat the oxidative stress.

  14. Do estrogenic compounds in drinking water migrating from plastic pipe distribution system pose adverse effects to human? An analysis of scientific literature.

    Science.gov (United States)

    Liu, Ze-Hua; Yin, Hua; Dang, Zhi

    2017-01-01

    With the widespread application of plastic pipes in drinking water distribution system, the effects of various leachable organic chemicals have been investigated and their occurrence in drinking water supplies is monitored. Most studies focus on the odor problems these substances may cause. This study investigates the potential endocrine disrupting effects of the migrating compound 2,4-di-tert-butylphenol (2,4-d-t-BP). The summarized results show that the migration of 2,4-d-t-BP from plastic pipes could result in chronic exposure and the migration levels varied greatly among different plastic pipe materials and manufacturing brands. Based on estrogen equivalent (EEQ), the migrating levels of the leachable compound 2,4-d-t-BP in most plastic pipes were relative low. However, the EEQ levels in drinking water migrating from four out of 15 pipes may pose significant adverse effects. With the increasingly strict requirements on regulation of drinking water quality, these results indicate that some drinking water transported with plastic pipes may not be safe for human consumption due to the occurrence of 2,4-d-t-BP. Moreover, 2,4-d-t-BP is not the only plastic pipe-migrating estrogenic compound, other compounds such as 2-tert-butylphenol (2-t-BP), 4-tert-butylphenol (4-t-BP), and others may also be leachable from plastic pipes.

  15. Intelligent information loss: the coding of facial identity, head pose, and non-face information in the macaque face patch system.

    Science.gov (United States)

    Meyers, Ethan M; Borzello, Mia; Freiwald, Winrich A; Tsao, Doris

    2015-05-06

    Faces are a behaviorally important class of visual stimuli for primates. Recent work in macaque monkeys has identified six discrete face areas where most neurons have higher firing rates to images of faces compared with other objects (Tsao et al., 2006). While neurons in these areas appear to have different tuning (Freiwald and Tsao, 2010; Issa and DiCarlo, 2012), exactly what types of information and, consequently, which visual behaviors neural populations within each face area can support, is unknown. Here we use population decoding to better characterize three of these face patches (ML/MF, AL, and AM). We show that neural activity in all patches contains information that discriminates between the broad categories of face and nonface objects, individual faces, and nonface stimuli. Information is present in both high and lower firing rate regimes. However, there were significant differences between the patches, with the most anterior patch showing relatively weaker representation of nonface stimuli. Additionally, we find that pose-invariant face identity information increases as one moves to more anterior patches, while information about the orientation of the head decreases. Finally, we show that all the information we can extract from the population is present in patterns of activity across neurons, and there is relatively little information in the total activity of the population. These findings give new insight into the representations constructed by the face patch system and how they are successively transformed. Copyright © 2015 the authors 0270-6474/15/357069-13$15.00/0.

  16. Consumption of Bt rice pollen containing Cry1C or Cry2A does not pose a risk to Propylea japonica (Thunberg) (Coleoptera: Coccinellidae).

    Science.gov (United States)

    Li, Yunhe; Zhang, Xiaojie; Chen, Xiuping; Romeis, Jörg; Yin, Xinming; Peng, Yufa

    2015-01-08

    As a pollen feeder, Propylea japonica would be directly exposed to Cry proteins in Bacillus thuringiensis (Bt)-transgenic rice fields. The effect of Cry1C- or Cry2A-containing transgenic rice pollen on the fitness of P. japonica was assessed using two dietary-exposure experiments in the laboratory. In the first experiment, larval developmental time of P. japonica was significantly longer when fed pollen from Bt rice lines rather than control pollen but other life table parameters were not significantly affected. In the second experiment, P. japonica was not affected when fed a rapeseed pollen-based diet containing purified Cry1C or Cry2A at concentrations that were >10-times higher than in pollen, but P. japonica was affected when the diet contained E-64 as a positive control. In both experiments, the stability and bioactivity of the Cry proteins in the food sources and the uptake of the proteins by P. japonica were confirmed. The results show that P. japonica is not sensitive to Cry1C or Cry2A proteins; the effect observed in the first experiment was likely attributable to unknown differences in the nutritional composition of Bt rice pollen. Overall, the data indicate that the growing of Cry1C- or Cry2A-transgenic rice should pose a negligible risk to P. japonica.

  17. A Fast, Accurate and Easy to Implement Method for Pose Recognition of an Intramedullary Nail using a Tracked C-arm

    Science.gov (United States)

    Esfandiari, H.; Amiri, S.; Lichti, D. D.; Anglin, C.

    2014-06-01

    A C-arm is a mobile X-ray device that is frequently used during orthopaedic surgeries. It consists of a semi-circular, arc-shaped arm that holds an X-ray transmitter at one end and an X-ray detector at the other. Intramedullary nail (IM nail) fixation is a popular orthopaedic surgery in which a metallic rod is placed into the patient's fractured bone (femur or tibia) and fixed using metal screws. The main challenge of IM-nail fixation surgery is to achieve the X-ray shot in which the distal holes of the IM nail appear as circles (desired view) so that the surgeon can easily insert the screws. Although C-arm X-ray devices are routinely used in IM-nail fixation surgeries, the surgeons or radiation technologists (rad-techs) usually use it in a trial-and-error manner. This method raises both radiation exposure and surgery time. In this study, we have designed and developed an IM-nail distal locking navigation technique that leads to more accurate and faster screw placement with a lower radiation dose and a minimum number of added steps to the operation to make it more accepted within the orthopaedic community. The specific purpose of this study was to develop and validate an automated technique for identifying the current pose of the IM nail relative to the C-arm. An accuracy assessment was performed to test the reliability of the navigation results. Translational accuracy was demonstrated to be better than 1 mm, roll and pitch rotations better than 2° and yaw rotational accuracy better than 2-5° depending on the separate angle. Computation time was less than 3.5 seconds.

  18. Mitigation of the threat posed to transfusion by donors traveling to Zika-affected areas: a Canadian risk-based approach.

    Science.gov (United States)

    Germain, Marc; Delage, Gilles; O'Brien, Sheila F; Grégoire, Yves; Fearon, Margaret; Devine, Dana

    2017-10-01

    The recent spread of the Zika virus to the Americas and the recognition that it can cause severe disease in the developing fetus has prompted the adoption of measures to mitigate the risk that this virus might pose to transfusion safety. In nonendemic countries, the risk to transfusion results from donors traveling to an endemic region. Canada implemented a 21-day temporary deferral for prospective donors who traveled to such regions. We present the rationale for this policy, including a quantitative risk assessment supported by a Monte Carlo simulation. The model considered the following parameters, each with specified values and ranges: the probability that a donor recently returned from a Zika-endemic region, the duration of travel to this region, the daily risk of acquiring Zika while in an endemic region, and the incubation and viremic periods. We ran the simulation 20 times, each with 10 million iterations. In the absence of any travel deferral, 32 donors (range, 20-46 donors) would be able to donate while still being at risk of transmitting Zika, corresponding to a rate of 1:312,500 (range, 1:217,000 to 1:500,000). None of these donors would be viremic beyond 21 days after returning from their travel, with a risk estimated at less than 1:200,000,000. A 21-day temporary travel deferral offers an extremely wide margin of safety for the possible transmission of Zika by a donation obtained from someone who recently returned from a country where the virus is circulating. © 2017 AABB.

  19. Evaluation of the pollution and human health risks posed by heavy metals in the atmospheric dust in Ebinur Basin in Northwest China.

    Science.gov (United States)

    Abuduwailil, Jilili; Zhaoyong, Zhang; Fengqing, Jiang

    2015-09-01

    Recently, a large amount of research assessing pollution levels and the related health risks posed by atmosphere dust has been undertaken worldwide. However, little work has been done in the oases of the arid regions of Northwest China. In this paper, we studied the pollution and health risks over a year of seven heavy metals in the atmospheric dust of Ebinur Basin, a typical oasis in Northwest China. The results showed the following: (1) The annual amount of atmospheric deposition in Ebinur Basin was 298.23 g m(-2) and the average monthly atmospheric deposition was 25.06 g m(-2). The average and maximum values of the seven heavy metals measured were all below the National Soil Environmental Quality Standards (2nd). (2) Heavy metals of Cu, Cr, and As in the atmospheric deposition mainly originated from the natural geological background, while Zn came from human activity. This study also showed that among the seven measured heavy metals, the ratios of the no-pollution status of Pb, Cd, and Hg were higher than those of others with moderate degrees of pollution also accounting for a certain ratio. (3) The carcinogenic risks from As, Cd, and Cr were all lower than the corresponding standard limit values, and these metals are considered not harmful to the health of the basin. However, there is a relatively high risk of exposure for children from hand-to-mouth intake, which is worthy of attention. This research showed that both human activity and natural factors, such as wind and altitude, influenced the heavy metal contents in the atmospheric dust of the study area. Furthermore, recent human activity in the study area had the most negative influence on the accumulation of the heavy metals and the corresponding health risks, especially for Hg, Pb, and Cd, which is worthy of attention.

  20. A Fast, Accurate and Easy to Implement Method for Pose Recognition of an Intramedullary Nail using a Tracked C-arm

    Directory of Open Access Journals (Sweden)

    H. Esfandiari

    2014-06-01

    Full Text Available A C-arm is a mobile X-ray device that is frequently used during orthopaedic surgeries. It consists of a semi-circular, arc-shaped arm that holds an X-ray transmitter at one end and an X-ray detector at the other. Intramedullary nail (IM nail fixation is a popular orthopaedic surgery in which a metallic rod is placed into the patient's fractured bone (femur or tibia and fixed using metal screws. The main challenge of IM-nail fixation surgery is to achieve the X-ray shot in which the distal holes of the IM nail appear as circles (desired view so that the surgeon can easily insert the screws. Although C-arm X-ray devices are routinely used in IM-nail fixation surgeries, the surgeons or radiation technologists (rad-techs usually use it in a trial-and-error manner. This method raises both radiation exposure and surgery time. In this study, we have designed and developed an IM-nail distal locking navigation technique that leads to more accurate and faster screw placement with a lower radiation dose and a minimum number of added steps to the operation to make it more accepted within the orthopaedic community. The specific purpose of this study was to develop and validate an automated technique for identifying the current pose of the IM nail relative to the C-arm. An accuracy assessment was performed to test the reliability of the navigation results. Translational accuracy was demonstrated to be better than 1 mm, roll and pitch rotations better than 2° and yaw rotational accuracy better than 2–5° depending on the separate angle. Computation time was less than 3.5 seconds.