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UAV-based multiple source localization and contour mapping of radiation fields
Redwan Newaz, Abdullah Al,Jeong, Sungmoon,Lee, Hosun,Ryu, Hyejeong,Chong, Nak Young Elsevier 2016 Robotics and autonomous systems Vol.85 No.-
<P><B>Abstract</B></P> <P>This paper proposes an efficient approach to the multiple source localization and contour mapping problem of radiation fields using Unmanned Aerial Vehicles (UAVs). A typical radiation field originating from a single hotspot can be generated by three spatial distributions of sources; scattered, clustered and biased. Of these, the clustered sources are relatively easy to localize, because the sources are located in a close proximity to the center of distribution. In other cases, it is not very straightforward, because, when multiple radiating sources generate a hotspot in a cumulative manner, sources do not coincide with the hotspot position. Regardless of our knowledge about the hotspot position, we attempt to solve the multiple radiation localization problem in two steps: the Region Of Interest (ROI) selection and the source localization. Existing algorithms eventually explore whole area, causing the problem of excessive use of UAV resources. We therefore propose a framework to reduce ROI in a radiation field that not only optimizes the resources but also increases the localization accuracy. For the source localization process, two different methods are employed interchangeably. Those methods are called the Hough Transform and the Variational Bayesian, adaptively selected with a switching technique and the overall performance is evaluated by balancing between the localization accuracy and the required exploration. In favor of the optimization, the prediction model defines the type of sources in a way that the adaptive switching methodology can converge to an optimal solution by selecting an appropriate method. Thus, the proposed framework enables the UAV to accurately localize the radiation sources in a fast manner. In order to verify the validity and the performance of the proposed strategies, we performed extensive numerical experiments with different numbers of sources and their positions. Our empirical results clearly show that the proposed approach outperforms existing individual approaches.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A framework is proposed that enables a single UAV to accurately localize the radiation sources in a fast manner. </LI> <LI> In an unknown radiation field, we attempt to solve the multiple radiation localization problem in two steps. </LI> <LI> By reducing the ROI in a radiation field, we not only optimize the resources but also are able to increase the localization accuracy. </LI> <LI> By employing two different methods interchangeably, we are able to balance between the localization accuracy and exploration constraints. </LI> </UL> </P>
Kinematic Analysis, Evaluation and Development of a New Wheelchair-Mounted Robotic Arm
Redwan M. Alqasemi,Edward J. McCaffrey,Kevin D. Edwards,Rajiv V. Dubey 한국과학기술원 인간친화 복지 로봇 시스템 연구센터 2006 International Journal of Assistive Robotics and Me Vol.7 No.2
This paper addresses kinematic analysis, evaluation and development of a wheelchair mounted robotic arm (WMRA). It addresses the kinematics of the WMRA with respect to its ability to perform activities of daily living (ADL). The procedure for kinematic analysis is applied to two commercial WMRAs. Design recommendations and insights with regard to each device are obtained and used to design a new WMRA to overcome the limitations of these devices. The new modular WMRA design is discussed and it is built to be a platform to further the evaluation of WMRA’s based on different link lengths. This method will benefit the researchers by providing a standardized procedure for kinematic analysis of WMRAs that is capable of evaluating independent designs and customizing the WMRA for specific users or tasks.
ON NONLINEAR ELLIPTIC EQUATIONS WITH SINGULAR LOWER ORDER TERM
Marah, Amine,Redwane, Hicham Korean Mathematical Society 2021 대한수학회보 Vol.58 No.2
We prove existence and regularity results of solutions for a class of nonlinear singular elliptic problems like $$\{-div\((a(x)+{\mid}u{\mid}^q){\nabla}u\)=\frac{f}{{\mid}u{\mid}^{\gamma}}{\text{ in }}{\Omega},\\{u=0\;on\;{\partial}{\Omega},$$ where Ω is a bounded open subset of ℝℕ(N ≥ 2), a(x) is a measurable nonnegative function, q, > 0 and the source f is a nonnegative (not identicaly zero) function belonging to Lm(Ω) for some m ≥ 1. Our results will depend on the summability of f and on the values of q, > 0.
Sameh R. Zaki,Mostafa Redwan,Ahmed M. Masoud,Ahmed A. Abdel Moneim 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.1
Halayieb area is located at the southeastern corner on the border between Egypt and Sudan. The area has very important strategic aspects to Egypt. Groundwater is the only source of fresh water in the area. The hydrogeochemical characterizations of groundwater in the area were carried out, to assess the quality of groundwater for its suitability for drinking and irrigation purposes. Geologically the Precambrian rocks underlain the Mesozoic sandstone and Tertiary marine sediments. The groundwater of the are a is recorded at the Miocene sedimentary succession and the fractured basement aquifers with a maximum water depth of 26.5 m from the ground surface. Groundwater quality is mostly saline caused by the sources of geogenic, anthropogenic, and marine origin of the water bearing formations. The resulting groundwater is characterized by Na+ > Ca2+ > Mg2+/Cl− > HCO3− > SO42−: Na+ > Ca2+ > K+/SO42− > Cl− > HCO3− facies, following the topographical and water flow-path conditions. The hydrochemical facies in this area fall in the field of NaCl type and the hydrogeochemical signatures indicated active hydrolysis and dissolution process of Ca-bearing minerals of the basement rocks and some sodium is lost, most probably through reverse ion exchange. Enrichment of Mn+ in some wells is regarded to the mining activity for manganese ores in the area. Groundwater quality is mostly not suitable for drinking purposes. For irrigation, the groundwater is mostly suitable in regard to the residual sodium carbonate and the magnesium hazard. According to the water quality assessment using United States salinity laboratory (USLL) diagram, most water samples located in category C3–S2, C3–S3, C3–S4, C4–S2 highlighting high to very high salinity hazard and medium to very high sodium content class. Most of the groundwater samples that are located away from the shoreline are suitable for livestock and poultry consumption. High salinity contents in the study area create severe problems for using water supplies and for future exploitation.
Investigating the spatial collision factors involved in bikeshare crashes at Washington, D.C
Showmitra Kumar Sarkar,Kazi Redwan Shabab,Palash Chandra Das,Mohamed H. Zaki 대한공간정보학회 2023 Spatial Information Research Vol.31 No.1
The objective of the study is to explore and characterize the spatial collision factors for bikeshare crashes using spatial and mathematical modeling. First, the nine most influential components behind the bikeshare crashes in Washington, D.C (179 census tracts) were selected as study variables (i.e., population density, number of bikeshare trips, etc.). Next, a spatial weight matrix was used to quantify the spatial relationships among the study variables with the bikeshare crashes. Finally, three models (i.e., Classic Regression, Spatial Lag, and Spatial Error) were used to investigate the essence of the interaction between these variables and bikeshare crashes. Finally, the spatial collision factors involved in bikeshare crashes were identified. According to model results, two causal factors (i.e., no. of cafe and no. of bikeshare points) significantly influence the bikeshare crashes in the Washington, D.C. area. The findings regarding spatial factors involved in bikeshare crashes can be useful in making optimum decisions regarding planning for bikeshare safety.
( Md Imtiazul Islam ),( Hoonhee Seo ),( Asma Redwan ),( Sukyung Kim ),( Saebim Lee ),( Mashuk Siddiquee ),( Ho-yeon Song ) 한국미생물 · 생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.1
Clostridioides difficile infection (CDI) is a significant cause of hospital-acquired and antibiotic-mediated intestinal diseases and is a growing global public health concern. Overuse of antibiotics and their effect on normal intestinal flora has increased the incidence and severity of infections. Thus, the development of new, effective, and safe treatment options is a high priority. Here, we report a new probiotic strain, Bacillus amyloliquefaciens (BA PMC-80), and its in vitro/in vivo anti-C. difficile effect as a prospective novel candidate for replacing conventional antibiotics. BA PMC-80 showed a significant anti-C. difficile effect in coculture assay, and its cell-free supernatant (CFS) also exhibited a considerable anti-C. difficile effect with an 89.06 μg/ml 50% minimal inhibitory concentration (MIC) in broth microdilution assay. The CFS was stable and equally functional under different pHs, heat, and proteinase treatments. It also exhibited a high sensitivity against current antibiotics and no toxicity in subchronic toxicity testing in hamsters. Finally, BA PMC-80 showed a moderate effect in a hamster CDI model with reduced infection severity and delayed death. However, further studies are required to optimize the treatment condition of the hamster CDI model for better efficacy and identify the antimicrobial compound produced by BA PMC-80.