The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform

Jianqiang Wang - One of the best experts on this subject based on the ideXlab platform.

  • problem formulation improvement for multi vehicle Collision avoidance and Impact mitigation
    IEEE Intelligent Vehicles Symposium, 2015
    Co-Authors: Ye Yuan, Jianqiang Wang
    Abstract:

    Multi-vehicle longitudinal Collision avoidance is a long-standing topic in vehicle control and Active Safety. In our previous work we formulated the multi-vehicle Collision avoidance and Impact mitigation problem assuming V2V (vehicle-to-vehicle communication) as a finite time horizon Model Predictive Control (MPC) problem. We intended to use the relative kinetic energy between the approaching vehicles as the measure of potential Collision Impact, which forms a quadratic objective function. However, the constraint representing vehicle approaching was not formulated appropriately, which caused a very stringent constraint to the feasible could set in the optimization at each time step of the sequential quadratic programming resulted from the MPC process. In this paper, we propose two improvements to the problem formulation: one is in the objective function and the other is in constraints. Performance comparisons between those algorithms are conducted to analyze the pros and cons of those two improvements through simulations.

N. Avcular - One of the best experts on this subject based on the ideXlab platform.

  • Collision behaviours of rubberized concrete
    Cement and Concrete Research, 1997
    Co-Authors: İlker Bekir Topçu, N. Avcular
    Abstract:

    Rubberized concrete is recommended for highway barriers. It was observed that rubberized concrete's acquired competency to absorb energy resulted in a decrease in damages and injuries during the Collision of vehicles with barriers. In this study, normal concrete was combined with two different sizes of rubber aggregate in order to examine the behaviours of rubberized concretes under Collision Impact. This was done through the comparison of experimental results. The Collision Impacts were researched as a dynamic problem, and the static results pertaining to cylindrical samples were converted into dynamic values. The values obtained were compared with values for both normal concrete and steel. The results showed that the Impact resistance of rubberized concrete was higher, and it was particularly evident in concrete samples aggregated with thick rubber.

Cheng Chen - One of the best experts on this subject based on the ideXlab platform.

  • Fuzzy Object Skeletonization: Theory, Algorithms, and Applications
    IEEE Transactions on Visualization and Computer Graphics, 2018
    Co-Authors: Punam K Saha, Gary E. Christensen, Cheng Chen
    Abstract:

    Skeletonization offers a compact representation of an object while preserving important topological and geometrical features. Literature on skeletonization of binary objects is quite mature. However, challenges involved with skeletonization of fuzzy objects are mostly unanswered. This paper presents a new theory and algorithm of skeletonization for fuzzy objects, evaluates its performance, and demonstrates its applications. A formulation of fuzzy grassfire propagation is introduced; its relationships with fuzzy distance functions, level sets, and geodesics are discussed; and several new theoretical results are presented in the continuous space. A notion of Collision-Impact of fire-fronts at skeletal points is introduced, and its role in filtering noisy skeletal points is demonstrated. A fuzzy object skeletonization algorithm is developed using new notions of surface- and curve-skeletal voxels, digital Collision-Impact, filtering of noisy skeletal voxels, and continuity of skeletal surfaces. A skeletal noise pruning algorithm is presented using branch-level significance. Accuracy and robustness of the new algorithm are examined on computer-generated phantoms and micro- and conventional CT imaging of trabecular bone specimens. An application of fuzzy object skeletonization to compute structure-width at a low image resolution is demonstrated, and its ability to predict bone strength is examined. Finally, the performance of the new fuzzy object skeletonization algorithm is compared with two binary object skeletonization methods.

  • curve skeletonization using minimum cost path
    Skeletonization#R##N#Theory Methods and Applications, 2017
    Co-Authors: Cheng Chen, Eric A. Hoffman, Punam K Saha
    Abstract:

    Abstract Skeletonization produces a compact representation of an object that reduces its dimensionality by one. In three dimensions, skeletons include both surface and curve structures. However, depending upon the primary aim of an application, especially those involving elongated objects, often, mere curve structures are sufficient to represent essential geometric and topologic features in an object. A skeleton that includes only curve structures is referred to as a curve skeletonization. This chapter reviews various definitions of a curve skeleton and different computational approaches. Conventional curve skeletonization algorithms using the principle of Blum's grassfire transform, often, produce unwanted spurious branches caused by boundary irregularities, digital effects, and other artifacts. Besides reviewing definitions and algorithms of curve skeletonization, a comprehensive solution using a minimum-cost path approach is described, and various important and related issues, e.g., centeredness of minimum-cost paths, Collision Impact, skeletal branch significance, etc. are discussed. A practical and efficient algorithm for the minimum-cost path based curve skeletonization is presented, and several applications are discussed.

  • ICIAP (1) - Filtering Non-Significant Quench Points Using Collision Impact in Grassfire Propagation
    Image Analysis and Processing — ICIAP 2015, 2015
    Co-Authors: Dakai Jin, Cheng Chen, Punam K Saha
    Abstract:

    The skeleton of an object is defined as the set of quench points formed during Blum’s grassfire transformation. Due to high sensitivity of quench points with small changes in the object boundary and the membership function (for fuzzy objects), often, a large number of redundant quench points is formed. Many of these quench points are caused by peripheral protrusions and dents and do not associate themselves with core shape features of the object. Here, we present a significance measure of quench points using the Collision Impact of fire-fronts and explore its role in filtering noisy quench points. The performance of the method is examined on three-dimensional shapes at different levels of noise and fuzziness, and compared with previous methods. The results have demonstrated that Collision Impact together with appropriate filtering kernels eliminate most of the noisy quench voxels while preserving those associated with core shape features of the object

Jason Forman - One of the best experts on this subject based on the ideXlab platform.

  • the tolerance of the human body to automobile Collision Impact a systematic review of injury biomechanics research 1990 2009
    Accident Analysis & Prevention, 2015
    Co-Authors: Jason Forman, Sonia Duprey, Dipan Bose, Eduardo Del Pozo De Dios, Damien Subit, Tim Gillispie, Jeff R. Crandall, Francisco J Lopezvaldes, Maria Seguigomez
    Abstract:

    Road traffic injuries account for 1.3 million deaths per year world-wide. Mitigating both fatalities and injuries requires a detailed understanding of the tolerance of the human body to external load. To identify research priorities, it is necessary to periodically compare trends in injury tolerance research to the characteristics of injuries occurring in the field. This study sought to perform a systematic review on the last twenty years of experimental injury tolerance research, and to evaluate those results relative to available epidemiologic data. Four hundred and eight experimental injury tolerance studies from 1990-2009 were identified from a reference index of over 68,000 papers. Examined variables included the body regions, ages, and genders studied; and the experimental models used. Most (20%) of the publications studied injury to the spine. There has also been a substantial volume of biomechanical research focused on upper and lower extremity injury, thoracic injury, and injury to the elderly - although these injury types still occur with regularity in the field. In contrast, information on pediatric injury and physiological injury (especially in the central nervous system) remains lacking. Given their frequency of injury in the field, future efforts should also include improving our understanding of tolerances and protection of vulnerable road users (e.g., motorcyclists, pedestrians).

  • The tolerance of the human body to automobile Collision Impact – a systematic review of injury biomechanics research, 1990–2009
    Accident; analysis and prevention, 2015
    Co-Authors: Jason Forman, Francisco J. Lopez-valdes, Sonia Duprey, Dipan Bose, Eduardo Del Pozo De Dios, Damien Subit, Tim Gillispie, Jeff R. Crandall, Maria Segui-gomez
    Abstract:

    Road traffic injuries account for 1.3 million deaths per year world-wide. Mitigating both fatalities and injuries requires a detailed understanding of the tolerance of the human body to external load. To identify research priorities, it is necessary to periodically compare trends in injury tolerance research to the characteristics of injuries occurring in the field. This study sought to perform a systematic review on the last twenty years of experimental injury tolerance research, and to evaluate those results relative to available epidemiologic data. Four hundred and eight experimental injury tolerance studies from 1990-2009 were identified from a reference index of over 68,000 papers. Examined variables included the body regions, ages, and genders studied; and the experimental models used. Most (20%) of the publications studied injury to the spine. There has also been a substantial volume of biomechanical research focused on upper and lower extremity injury, thoracic injury, and injury to the elderly - although these injury types still occur with regularity in the field. In contrast, information on pediatric injury and physiological injury (especially in the central nervous system) remains lacking. Given their frequency of injury in the field, future efforts should also include improving our understanding of tolerances and protection of vulnerable road users (e.g., motorcyclists, pedestrians).

Punam K Saha - One of the best experts on this subject based on the ideXlab platform.

  • Fuzzy Object Skeletonization: Theory, Algorithms, and Applications
    IEEE Transactions on Visualization and Computer Graphics, 2018
    Co-Authors: Punam K Saha, Gary E. Christensen, Cheng Chen
    Abstract:

    Skeletonization offers a compact representation of an object while preserving important topological and geometrical features. Literature on skeletonization of binary objects is quite mature. However, challenges involved with skeletonization of fuzzy objects are mostly unanswered. This paper presents a new theory and algorithm of skeletonization for fuzzy objects, evaluates its performance, and demonstrates its applications. A formulation of fuzzy grassfire propagation is introduced; its relationships with fuzzy distance functions, level sets, and geodesics are discussed; and several new theoretical results are presented in the continuous space. A notion of Collision-Impact of fire-fronts at skeletal points is introduced, and its role in filtering noisy skeletal points is demonstrated. A fuzzy object skeletonization algorithm is developed using new notions of surface- and curve-skeletal voxels, digital Collision-Impact, filtering of noisy skeletal voxels, and continuity of skeletal surfaces. A skeletal noise pruning algorithm is presented using branch-level significance. Accuracy and robustness of the new algorithm are examined on computer-generated phantoms and micro- and conventional CT imaging of trabecular bone specimens. An application of fuzzy object skeletonization to compute structure-width at a low image resolution is demonstrated, and its ability to predict bone strength is examined. Finally, the performance of the new fuzzy object skeletonization algorithm is compared with two binary object skeletonization methods.

  • curve skeletonization using minimum cost path
    Skeletonization#R##N#Theory Methods and Applications, 2017
    Co-Authors: Cheng Chen, Eric A. Hoffman, Punam K Saha
    Abstract:

    Abstract Skeletonization produces a compact representation of an object that reduces its dimensionality by one. In three dimensions, skeletons include both surface and curve structures. However, depending upon the primary aim of an application, especially those involving elongated objects, often, mere curve structures are sufficient to represent essential geometric and topologic features in an object. A skeleton that includes only curve structures is referred to as a curve skeletonization. This chapter reviews various definitions of a curve skeleton and different computational approaches. Conventional curve skeletonization algorithms using the principle of Blum's grassfire transform, often, produce unwanted spurious branches caused by boundary irregularities, digital effects, and other artifacts. Besides reviewing definitions and algorithms of curve skeletonization, a comprehensive solution using a minimum-cost path approach is described, and various important and related issues, e.g., centeredness of minimum-cost paths, Collision Impact, skeletal branch significance, etc. are discussed. A practical and efficient algorithm for the minimum-cost path based curve skeletonization is presented, and several applications are discussed.

  • ICIAP (1) - Filtering Non-Significant Quench Points Using Collision Impact in Grassfire Propagation
    Image Analysis and Processing — ICIAP 2015, 2015
    Co-Authors: Dakai Jin, Cheng Chen, Punam K Saha
    Abstract:

    The skeleton of an object is defined as the set of quench points formed during Blum’s grassfire transformation. Due to high sensitivity of quench points with small changes in the object boundary and the membership function (for fuzzy objects), often, a large number of redundant quench points is formed. Many of these quench points are caused by peripheral protrusions and dents and do not associate themselves with core shape features of the object. Here, we present a significance measure of quench points using the Collision Impact of fire-fronts and explore its role in filtering noisy quench points. The performance of the method is examined on three-dimensional shapes at different levels of noise and fuzziness, and compared with previous methods. The results have demonstrated that Collision Impact together with appropriate filtering kernels eliminate most of the noisy quench voxels while preserving those associated with core shape features of the object