scholarly journals Robotic embankment

2021 ◽  
Author(s):  
Dominic Jud ◽  
Ilmar Hurkxkens ◽  
Christophe Girot ◽  
Marco Hutter
Keyword(s):  
Survey Design ◽  
Free Form ◽  
Average Error ◽  
Design Environment ◽  
Labour Shortage ◽  
Dynamic Landscape ◽  
Landscape System ◽  
Autonomous Excavation ◽  
Cut And Fill ◽  
Terrain Modelling

AbstractAutomating earth-moving tasks has the potential to resolve labour-shortage, allow for unseen designs and foster sustainability through using on-site materials. In this interdisciplinary project involving robotics and landscape architecture, we combine our previous work on autonomous excavation of free-form shapes, dynamic landscape design and terrain modelling tools into a robotic landscape system. It tightly connects survey, design and fabrication to exchange information in real-time during fabrication. We purposely built a LiDAR survey drone for tight integration. The design environment contains terrain modelling tools to balance cut and fill volumes for material-neutral, on-site construction. Its parametric nature allows it to adapt the geometry to changing site conditions during fabrication. Our autonomous walking excavator is used to create these free-form shapes in natural granular material. We propose an excavation planner for free-form embankments that computes the next excavation location and subsequently the location where the excavated soil should be dumped. This robotic excavation system achieves the world’s first autonomous completion of free-form embankments with high accuracy. A $$20\hbox { m}$$ 20 m long S-shaped and a two-faced embankment with a corner with roughly 0.03–0.05 m average error were created.

scholarly journals Host Mesh Fitting of a Generic Musculoskeletal Model of the Lower Limbs to Subject-Specific Body Surface Data: A Validation Study

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Katja Oberhofer ◽  
Silvio Lorenzetti ◽  
Kumar Mithraratne
Keyword(s):  
Gait Analysis ◽  
Body Surface ◽  
Lower Limb ◽  
Study Groups ◽  
Musculoskeletal Model ◽  
Lower Limbs ◽  
Free Form ◽  
Average Error ◽  
Surface Data ◽  
Subject Specific

Challenges remain in accurately capturing the musculoskeletal geometry of individual subjects for clinical and biomechanical gait analysis. The aim of this study was to use and validate the Host Mesh Fitting (HMF) technique for fitting a generic anatomically based musculoskeletal model to 3D body surface data of individual subjects. The HMF technique is based on the free-form idea of deforming geometrically complex structures according to the deformation of a surrounding volumetric mesh. Using the HMF technique, an anatomically based model of the lower limbs of an adult female subject (29 years) was customized to subject-specific skin surface data of five typically developing children (mean age 10.2 years) and six children with Cerebral Palsy (CP) (mean age 9.6 years). The fitted lengths and volumes of six muscle-tendon structures were compared against measures from Magnetic Resonance (MR) images for validation purposes. The HMF technique resulted in accurate approximations of the lower limb shapes of all subjects in both study groups. The average error between the MR data and the fitted muscle-tendon lengths from HMF was 4±4% in children without CP and 7±5% in children with CP, respectively. The average error between the MR data and the fitted muscle volumes from HMF was 28±19% in children without CP and 27±28% in children with CP, respectively. This study presents a crucial step towards personalized musculoskeletal modelling for gait analysis by demonstrating the feasibility of fitting a generic anatomically based lower limb model to 3D body surface data of children with and without CP using the HMF technique. Additional improvements in the quality of fit are expected to be gained by developing age-matched generic models for different study groups, accounting for subject-specific variations in subcutaneous body fat, as well as considering supplementary data from ultrasound imaging to better capture physiological muscle tissue properties.

A fuzzy neural network approach for modeling the growth kinetics of FeB and Fe2B layers during the boronizing process

2018 ◽  
Vol 106 (6) ◽  
pp. 603 ◽  
Author(s):  
Bendaoud Mebarek ◽  
Mourad Keddam
Keyword(s):  
Neural Network ◽  
Experimental Data ◽  
Fuzzy Neural Network ◽  
Treatment Time ◽  
Calculation Model ◽  
Average Error ◽  
Network Approach ◽  
Neural Network Approach ◽  
Fuzzy Neural ◽  
Kinetics Of

In this paper, we develop a boronizing process simulation model based on fuzzy neural network (FNN) approach for estimating the thickness of the FeB and Fe2B layers. The model represents a synthesis of two artificial intelligence techniques; the fuzzy logic and the neural network. Characteristics of the fuzzy neural network approach for the modelling of boronizing process are presented in this study. In order to validate the results of our calculation model, we have used the learning base of experimental data of the powder-pack boronizing of Fe-15Cr alloy in the temperature range from 800 to 1050 °C and for a treatment time ranging from 0.5 to 12 h. The obtained results show that it is possible to estimate the influence of different process parameters. Comparing the results obtained by the artificial neural network to experimental data, the average error generated from the fuzzy neural network was 3% for the FeB layer and 3.5% for the Fe2B layer. The results obtained from the fuzzy neural network approach are in agreement with the experimental data. Finally, the utilization of fuzzy neural network approach is well adapted for the boronizing kinetics of Fe-15Cr alloy.

Minimal contribution of cell-bound antibodies to the immunoscintigraphy of inflamed joints with 99mTc-anti-CD4 monoclonal antibodies

2002 ◽  
Vol 41 (03) ◽  
pp. 129-134 ◽  
Author(s):  
A. Wolski ◽  
E. Palombo-Kinne ◽  
F. Wolf ◽  
F. Emmrich ◽  
W. Becker ◽  
...  
Keyword(s):  
T Cells ◽  
Monoclonal Antibodies ◽  
Synovial Membrane ◽  
In Vitro Release ◽  
Peritoneal Macrophages ◽  
Lymphoid Organs ◽  
Whole Body ◽  
Free Form ◽  
Ankle Joints

Summary Aim: The cellular joint infiltrate in rheumatoid arthritis patients is rich in CD4-positive T-helper lymphocytes and macrophages, rendering anti-CD4 monoclonal antibodies (mAbs) suitable for specific immunoscintigraphy of human/ experimental arthritis. Following intravenous injection, however, mAbs are present both in the free form and bound to CD4-positive, circulating monocytes and T-cells. Thus, the present study aimed at analyzing the relative contribution of the free and the cell-bound component to the imaging of inflamed joints in experimental adjuvant arthritis (AA). Methods: AA rat peritoneal macrophages or lymph node T-cells were incubated in vitro with saturating amounts of 99mTc-anti-CD4 mAb (W3/25) and injected i.v. into rats with AA. Results: In vitro release of 99mTc-anti-CD4 mAb from the cells was limited (on average 1.57%/h for macrophages and 0.84%/h for T-cells). Following i.v. injection, whole body/joint scans and tissue measurements showed only negligible accumulation of radioactivity in inflamed ankle joints (tissue: 0.22 and 0.34% of the injected activity, respectively), whereas the radioactivity was concentrated in liver (tissue: 79% and 71%, respectively), kidney, and urinary bladder. Unlike macrophages, however, anti-CD4 mAb-coated T-cells significantly accumulated in lymphoid organs, the inflamed synovial membrane of the ankle joints, as well as in elbow and knee joints. Conclusion: While the overall contribution of cell-bound mAbs to the imaging of arthritic joints with anti-CD4 mAbs is minimal, differential accumulation of macrophages and T-cells in lymphoid organs and the inflamed synovial membrane indicates preferential migration patterns of these 2 cell populations in arthritic rats. Although only validated for 99mTc-anti-CD4 mAbs, extrapolation of the results to other anticellular mAbs with similar affinity for their antigen may be possible.

Immunoreactivity of Tissue Plasminogen Activator and of Its Inhibitor Complexes

1989 ◽  
Vol 61 (03) ◽  
pp. 409-414 ◽  
Author(s):  
M Rånby ◽  
G Nguyen ◽  
P Y Scarabin ◽  
M Samama
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Degradation Products ◽  
Gel Filtration ◽  
Free Form ◽  
Enzyme Linked Immunosorbent Assay ◽  
Plasma Samples ◽  
Significant Difference ◽  
Tissue Plasminogen ◽  
Pai 1

SummaryAn enzyme linked immunosorbent assay (ELISA) based on goat polyclonal antibodies against human tissue plasminogen activator (tPA) was evaluated. The relative immunoreactivity of tPA in free form and tPA in complex with inhibitors was estimated by ELISA and found to be 100, 74, 94, 92 and 8l% for free tPA and tPA in complex with PAI-1, PAI-2, α2-antiplasmin and C1-inhibitor, respectively. Addition of tPA to PAI-1 rich plasma resulted in rapid and total loss of tPA activity without detectable loss of ELISA response, indicating an immunoreactivity of tPA in tPA/PAI-1 complex of about l00%. Three different treatments of citrated plasma samples (acidification/reneutralization, addition of 5 mM EDTA or of 0.5 M lysine) prior to determination by ELISA all resulted in increased tPA levels. The fact that the increase was equally large in all three cases along with good analytical recovery of tPA added to plasffi, supported the notion that all tPA antigen present in plasma samples is measured by the ELISA. Analysis by ELISA of fractions obtained by gel filtration of plasma from a patient undergoing tPA treatment identified tPA/inhibitor complexes and free tPA but no low molecular weight degradation products of tPA. Determinations of tPA antigen were made at seven French clinical laboratories on coded and randomized plasma samples with known tPA antigen content. For undiluted samples there was no significant difference between the tPA levels found and those known to be present. The between-assay coefficient of variation was 7 to 10%. In conclusion, the ELISA appeared suited for determination of total tPA antigen in human plasma samples.

The Different Forms of Antithrombin III in Serum

1977 ◽  
Vol 38 (02) ◽  
pp. 0494-0503 ◽  
Author(s):  
D. S Pepper ◽  
D Banhegyi ◽  
J. D Cash
Keyword(s):  
Molecular Weight ◽  
Affinity Chromatography ◽  
Human Serum ◽  
Degradation Product ◽  
Antithrombin Iii ◽  
Gel Filtration ◽  
Free Form ◽  
Polymeric Form ◽  
At Iii ◽  
Human Thrombin

SummaryAntithrombin III (AT III) complexes were isolated from human serum by affinity chromatography and gel filtration. In the first step of the preparation, using heparin-agarose chromatography, we observed that the complexed form of AT III bound less strongly to the gel than the free form and that about half of the AT III was free. With further purification a 2.5 × 105 molecular weight complex was isolated. Using 125I labelled human thrombin, this complex was radioactive indicating the presence of thrombin. Only in a synthetic thrombin-AT III system was a 9 × 104 molecular weight complex detected, but not in serum. These facts suggest that in serum AT III complexes may exist in a polymeric form. Also, an AT III antigen derived from the original AT III molecule, but not complexed, was isolated which may be a degradation product.Abbreviations used: AT-III, antithrombin III. Hepes, N-2-Hydroxyethylpiperazine-N-2-Ethanesulphonic acid.

Effect of Depolymerized Holothurian Glycosaminoglycan (DHG) on Tissue Factor Pathway Inhibitor: In Vitro and In Vivo Studies

1997 ◽  
Vol 78 (02) ◽  
pp. 864-870 ◽  
Author(s):  
Hideki Nagase ◽  
Kei-ichi Enjyoji ◽  
Yu-ichi Kamikubo ◽  
Keiko T Kitazato ◽  
Kenji Kitazato ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Tissue Factor Pathway Inhibitor ◽  
Factor Xa ◽  
Free Form ◽  
Initial Reaction ◽  
Extrinsic Pathway ◽  
Factor Xa Inhibition ◽  
Tissue Factor Pathway

SummaryDepolymerized holothurian glycosaminoglycan (DHG) is a glycosaminoglycan extracted from the sea cucumber Stichopus japonicusSelenka. In previous studies, we demonstrated that DHG has antithrombotic and anticoagulant activities that are distinguishable from those of heparin and dermatan sulfate. In the present study, we examined the effect of DHG on the tissue factor pathway inhibitor (TFPI), which inhibits the initial reaction of the tissue factor (TF)-mediated coagulation pathway. We first examined the effect of DHG on factor Xa inhibition by TFPI and the inhibition of TF-factor Vila by TFPI-factor Xa in in vitro experiments using human purified proteins. DHG increased the rate of factor Xa inhibition by TFPI, which was abolished either with a synthetic C-terminal peptide or with a synthetic K3 domain peptide of TFPI. In contrast, DHG reduced the rate of TF-factor Vila inhibition by TFPI-factor Xa. Therefore, the effect of DHG on in vitroactivity of TFPI appears to be contradictory. We then examined the effect of DHG on TFPI in cynomolgus monkeys and compared it with that of unfractionated heparin. DHG induced an increase in the circulating level of free-form TFPI in plasma about 20-fold when administered i.v. at 1 mg/kg. The prothrombin time (PT) in monkey plasma after DHG administration was longer than that estimated from the plasma concentrations of DHG. Therefore, free-form TFPI released by DHG seems to play an additive role in the anticoagulant mechanisms of DHG through the extrinsic pathway in vivo. From the results shown in the present work and in previous studies, we conclude that DHG shows anticoagulant activity at various stages of coagulation reactions, i.e., by inhibiting the initial reaction of the extrinsic pathway, by inhibiting the intrinsic Xase, and by inhibiting thrombin.

PERCEIVED EFFECTS OF STREET HAWKING ON THE WELL-BEING OF CHILDREN IN ANYIGBA, DEKINA LOCAL GOVERNMENT AREA OF KOGI STATE, NIGERIA

2018 ◽  
Vol 8 (1) ◽  
pp. 01-07
Author(s):  
Alfred Eboh
Keyword(s):  
Local Government ◽  
Survey Design ◽  
Sampling Technique ◽  
Well Being ◽  
Local Government Area ◽  
Negative Consequences ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Perceived Effects ◽  
The Government

Background: The hawking of wares by children has been a serious issue confronting the Nigerian society. Children hawk in some of the most horrible conditions conceivable, where they face a serious risk of injury, chronic illness, kidnapping, rape or death. Objective: The focus of this study was to assess the perceived effects of street hawking on the well-being of children in Anyigba, Dekina Local Government Area of Kogi State. Methods: The population of this study consists of parents of the street hawkers in Anyigba while cross-sectional survey design was used through the purposive sampling technique to choose the sample size of one hundred and sixty-two (162) respondents. The validated structured questionnaire and In-Depth Interviews (IDIs) served as the instruments for the data collection respectively. The hypotheses were tested using Chi-Square at a predetermined 0.05 level of significance. The quantitative data were analysed with the aid of the SPSS (version 20). Results: The results indicated among others that street hawking had significant social implications and physical consequences on children's moral behaviour as well as health status in the study area. Conclusion: The study, therefore, concluded that the government of Kogi State should carry out an enlightenment campaign through the media and religious institutions on the negative consequences of street hawking are recommended as panacea. Also, the child right act instrument and its implementation should be strengthened in order to curb street hawking in the study area.

Towards an interdisciplinary knowledge exchange model

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Santiago DE FRANCISCO ◽  
Diego MAZO
Keyword(s):  
Design Research ◽  
Knowledge Exchange ◽  
Academic Research ◽  
Innovation Process ◽  
The United States ◽  
Design Environment ◽  
Interdisciplinary Knowledge ◽  
One Year ◽  
The University ◽  
Common Situation

Universities and corporates, in Europe and the United States, have come to a win-win relationship to accomplish goals that serve research and industry. However, this is not a common situation in Latin America. Knowledge exchange and the co-creation of new projects by applying academic research to solve company problems does not happen naturally.To bridge this gap, the Design School of Universidad de los Andes, together with Avianca, are exploring new formats to understand the knowledge transfer impact in an open innovation network aiming to create fluid channels between different stakeholders. The primary goal was to help Avianca to strengthen their innovation department by apply design methodologies. First, allowing design students to proposed novel solutions for the traveller experience. Then, engaging Avianca employees to learn the design process. These explorations gave the opportunity to the university to apply design research and academic findings in a professional and commercial environment.After one year of collaboration and ten prototypes tested at the airport, we can say that Avianca’s innovation mindset has evolved by implementing a user-centric perspective in the customer experience touch points, building prototypes and quickly iterate. Furthermore, this partnership helped Avianca’s employees to experience a design environment in which they were actively interacting in the innovation process.

Immigration and the tech industry: As a labour shortage remedy, for innovation, or for cost savings?

2013 ◽  
Vol 10 (2) ◽  
pp. 201-227 ◽  
Author(s):  
Norman Matloff
Keyword(s):  
Immigration Policy ◽  
Brain Drain ◽  
Cost Savings ◽  
Foreign Workers ◽  
Service Firms ◽  
It Service ◽  
Labour Shortage ◽  
Labour Costs ◽  
Using Data ◽  
The U.S

The two main reasons cited by the U.S. tech industry for hiring foreign workers--remedying labour shortages and hiring "the best and the brightest"--are investigated, using data on wages, patents, and R&D work, as well as previous research and industry statements. The analysis shows that the claims of shortage and outstanding talent are not supported by the data, even after excluding the Indian IT service firms. Instead, it is shown that the primary goals of employers in hiring  foreign workers are to reduce labour costs and to obtain "indentured" employees. Current immigration policy is causing an ‘Internal Brain Drain’ in STEM.

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