266 research outputs found
A review of three-dimensional imaging technologies for pavement distress detection and measurements
With the ever-increasing emphasis on maintaining road assets to a high standard, the need for fast accurate inspection for road distresses is becoming extremely important. Surface distresses on roads are essentially three dimensional (3-D) in nature. Automated visual surveys are the best option available. However, the imaging conditions, in terms of lighting, etc., are very random. For example, the challenge of measuring the volume of the pothole requires a large field of view with a reasonable spatial resolution, whereas microtexture evaluation requires very accurate imaging. Within the two extremes, there is a range of situations that require 3-D imaging. Three-dimensional imaging consists of a number of techniques such as interferometry and depth from focus. Out of these, laser imagers are mainly used for road surface distress inspection. Many other techniques are relatively unknown among the transportation community, and industrial products are rare. The main impetus for this paper is derived from the rarity of 3-D industrial imagers that employ alternative techniques for use in transportation. In addition, the need for this work is also highlighted by a lack of literature that evaluates the relative merits/demerits of various imaging methods for different distress measurement situations in relation to pavements. This overview will create awareness of available 3-D imaging methods in order to help make a fast initial technology selection and deployment. The review is expected to be helpful for researchers, practicing engineers, and decision makers in transportation engineering
Fast Segmentation of Industrial Quality Pavement Images using Laws Texture Energy Measures and k-Means Clustering
Thousands of pavement images are collected by road authorities daily for condition monitoring surveys. These images typically have intensity variations and texture non-uniformities making their segmentation challenging. The automated segmentation of such pavement images is crucial for accurate, thorough and expedited health monitoring of roads. In the pavement monitoring area, well known texture descriptors such as gray-level co-occurrence matrices and local binary patterns are often used for surface segmentation and identification. These, despite being the established methods for texture discrimination, are inherently slow. This work evaluates Laws texture energy measures as a viable alternative for pavement images for the first time. k-means clustering is used to partition the feature space, limiting the human subjectivity in the process. Data classification, hence image segmentation, is performed by the k-nearest neighbor method. Laws texture energy masks are shown to perform well with resulting accuracy and precision values of more than 80%. The implementations of the algorithm, in both MATLAB and OpenCV/C++, are extensively compared against the state of the art for execution speed, clearly showing the advantages of the proposed method. Furthermore, the OpenCV based segmentation shows a 100% increase in processing speed when compared to the fastest algorithm available in literature
Tiled fuzzy Hough transform for crack detection
Surface cracks can be the bellwether of the failure of any component under loading as it indicates the component's fracture due to stresses and usage. For this reason, crack detection is indispensable for the condition monitoring and quality control of road surfaces. Pavement images have high levels of intensity variation and texture content, hence the crack detection is difficult. Moreover, shallow cracks result in very low contrast image pixels making their detection difficult. For these reasons, studies on pavement crack detection is active even after years of research. In this paper, the fuzzy Hough transform is employed, for the first time to detect cracks on any surface. The contribution of texture pixels to the accumulator array is reduced by using the tiled version of the Hough transform. Precision values of 78% and a recall of 72% are obtaining for an image set obtained from an industrial imaging system containing very low contrast cracking. When only high contrast crack segments are considered the values move to mid to high 90%
Glucocorticoids promote Von Hippel Lindau degradation and Hif-1α stabilization
Glucocorticoid (GC) and hypoxic transcriptional responses play a central role in tissue homeostasis and regulate the cellular response to stress and inflammation, highlighting the potential for cross-talk between these two signaling pathways. We present results from an unbiased in vivo chemical screen in zebrafish that identifies GCs as activators of hypoxia-inducible factors (HIFs) in the liver. GCs activated consensus hypoxia response element (HRE) reporters in a glucocorticoid receptor (GR)-dependent manner. Importantly, GCs activated HIF transcriptional responses in a zebrafish mutant line harboring a point mutation in the GR DNA-binding domain, suggesting a nontranscriptional route for GR to activate HIF signaling. We noted that GCs increase the transcription of several key regulators of glucose metabolism that contain HREs, suggesting a role for GC/HIF cross-talk in regulating glucose homeostasis. Importantly, we show that GCs stabilize HIF protein in intact human liver tissue and isolated hepatocytes. We find that GCs limit the expression of Von Hippel Lindau protein (pVHL), a negative regulator of HIF, and that treatment with the c-src inhibitor PP2 rescued this effect, suggesting a role for GCs in promoting c-src–mediated proteosomal degradation of pVHL. Our data support a model for GCs to stabilize HIF through activation of c-src and subsequent destabilization of pVHL
A theoretical analysis of billiard ball dynamics under cushion impacts
The last two decades have seen a growing interest in research related to billiards.
There have been a number of projects aimed at developing training systems, robots, and computer
simulations for billiards. Determination of billiard ball trajectories is important for all of
these systems. The ball’s collision with a cushion is often encountered in billiards and it drastically
changes the ball trajectory, especially when the ball has spin. This work predicts ball bounce
angles and bounce speeds for the ball’s collision with a cushion, under the assumption of insignificant
cushion deformation. Differential equations are derived for the ball dynamics during the
impact and these equations are solved numerically. The numerical solutions together with previous
experimental work by the authors predict that for the ball–cushion collision, the values of
the coefficient of restitution and the sliding coefficient of friction are 0.98 and 0.14, respectively.
A comparison of the numerical and experimental results indicates that the limiting normal velocity
under which the rigid cushion assumption is valid is 2.5 m/s. A number of plots that show
the rebound characteristics for given ball velocity–spin conditions are also provided. The plots
quantify various phenomena that have hitherto only been described in the billiards literature
Formulation and evaluation of herbal face cream with green tea extract
Face cream is a semi-solid preparation for improving skin colour. The purposes of the present research work was to formulate and evaluate herbal face cream with green tea extract, turmeric, aloe vera gel as a skin toner. Herbal creams offer several advantages over synthetic creams. The majority of existing creams which has prepared from drugs of synthetic origin and gives extras fairness to face, but it has several side effects such as itching or several allergic reactions. Herbal creams do not have any of these side effects, without side effects it gives the nourishment to skin. Method carried out to prepare herbal cream was vanishing cream formulation. Firstly, oil phase was prepared, Secondly aqueous phase was prepared. Then aqueous phase was added into the oil phase at 700 c with continuous stirring. Now, once the transfer was completed it was allowed to come at room temperature all the while being stirred. Perfume was added at last just before the finished product was transferred to suitable container. The above prepared herbal cream was evaluated with parameters such as pH, homogeneity by visual and by touch, appearance (colour), rub out (spread ability, wetness), washability, consistency and emolliency. The study suggests that the composition of extract and the base of the cream F1 are more stable and safe
Automatic Detection of User Abilities through the SmartAbility Framework
This paper presents a proposed smartphone application for the unique SmartAbility Framework that
supports interaction with technology for people with reduced physical ability, through focusing on
the actions that they can perform independently. The Framework is a culmination of knowledge
obtained through previously conducted technology feasibility trials and controlled usability
evaluations involving the user community. The Framework is an example of ability-based design that
focuses on the abilities of users instead of their disabilities. The paper includes a summary of
Versions 1 and 2 of the Framework, including the results of a two-phased validation approach,
conducted at the UK Mobility Roadshow and via a focus group of domain experts. A holistic model
developed by adapting the House of Quality (HoQ) matrix of the Quality Function Deployment (QFD)
approach is also described. A systematic literature review of sensor technologies built into smart
devices establishes the capabilities of sensors in the Android and iOS operating systems. The review
defines a set of inclusion and exclusion criteria, as well as search terms used to elicit literature from
online repositories. The key contribution is the mapping of ability-based sensor technologies onto
the Framework, to enable the future implementation of a smartphone application. Through the
exploitation of the SmartAbility application, the Framework will increase technology amongst people
with reduced physical ability and provide a promotional tool for assistive technology manufacturers
A gas cell for stopping, storing and polarizing radioactive particles
A radioactive beam of 20Na is stopped in a gas cell filled with Ne gas. The
stopped particles are polarized by optical pumping. The degree of polarization
that can be achieved is studied. A maximum polarization of 50% was found. The
dynamic processes in the cell are described with a phenomenological model.Comment: 16 pages, 6 figure
Climate change and rice production in Sri Lanka: short-run vs. long-run symmetric and asymmetric effects
This study explores climate change's symmetric and asymmetric impacts on rice production in Sri Lanka, a crucial sector for food security in the country. The analysis utilized Autoregressive Distributed Lag (ARDL) and Non-linear Autoregressive Distributed Lag (NARDL) models. This study analyses annual data from 1952 to 2022 to capture relationships among the study variables. The ARDL findings reveal that temperature and cultivated land area have a significant long-term effect on rice production. The NARDL model reveals that positive and negative changes in climate variables have asymmetrical long-term impacts. Positive changes in temperature and rainfall lead to a notable decline in rice yields in the long term. Negative rainfall changes create a significant beneficial effect on rice production in the long term. Cultivated land area shows a significant positive impact on rice yield in the long term. The results of symmetric and asymmetric climate change impact are essential for formulating agricultural climate adaptation policies, such as promoting climate resilience rice varieties, improving irrigation and water management, developing early warning systems that promote sustainability and enhance climate adaptation strategies, ensuring food security in Sri Lanka
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A high level of liver-specific expression of oncogenic KrasV12 drives robust liver tumorigenesis in transgenic zebrafish
Human liver cancer is one of the deadliest cancers worldwide, with hepatocellular carcinoma (HCC) being the most common type. Aberrant Ras signaling has been implicated in the development and progression of human HCC, but a complete understanding of the molecular mechanisms of this protein in hepatocarcinogenesis remains elusive. In this study, a stable in vivo liver cancer model using transgenic zebrafish was generated to elucidate Ras-driven tumorigenesis in HCC. Using the liver-specific fabp10 (fatty acid binding protein 10) promoter, we overexpressed oncogenic kras[superscript V12] specifically in the transgenic zebrafish liver. Only a high level of kras[superscript V12] expression initiated liver tumorigenesis, which progressed from hyperplasia to benign and malignant tumors with activation of the Ras-Raf-MEK-ERK and Wnt–β-catenin pathways. Histological diagnosis of zebrafish tumors identified HCC as the main lesion. The tumors were invasive and transplantable, indicating malignancy of these HCC cells. Oncogenic kras[superscript V12] was also found to trigger p53-dependent senescence as a tumor suppressive barrier in the pre-neoplastic stage. Microarray analysis of zebrafish liver hyperplasia and HCC uncovered the deregulation of several stage-specific and common biological processes and signaling pathways responsible for kras[superscript V12]-driven liver tumorigenesis that recapitulated the molecular hallmarks of human liver cancer. Cross-species comparisons of cancer transcriptomes further defined a HCC-specific gene signature as well as a liver cancer progression gene signature that are evolutionarily conserved between human and zebrafish. Collectively, our study presents a comprehensive portrait of molecular mechanisms during progressive Ras-induced HCC. These observations indicate the validity of our transgenic zebrafish to model human liver cancer, and this model might act as a useful platform for drug screening and identifying new therapeutic targets.This is the publisher’s final PDF plus Supplementary Material. The published article is copyrighted by The Company of Biologists Ltd. and can be found at: http://dmm.biologists.org
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