Software:Virtual Soldier Research Program

From HandWiki

The Virtual Soldier Research program (VSR) is a research group within the University of Iowa Center for Computer-Aided Design (CCAD). VSR was founded by Professor Karim Abdel-Malek in 2003 through external funding from the US Army Tank Automotive Command (TACOM) to put the Warfighter at the center of US Army product designs.[1] Professor Abdel-Malek's background in robotics and the use of rigorous mathematical formulations was the first introduction of mathematical kinematics to the field of Digital Human Modeling (DHM).[2][3][4][5][6][7] Prior to 2003, all DHM models were based on experimental data that use lookup tables to enable the posturing of simple mannequins. Indeed, the first version of Santos, presented at the a DHM conference was met with great success because it was the first fully articulated digital human model that behaved as humans do,[8] whereby joints had constraints (also called ranges of motion) and a user could pull on an arm for example and as a result the entire body would respond accordingly. Cost functions representing human performance measures were used to drive the motion within the optimization formulation.[9][10][8] Seated posture prediction for example was accomplished by simply providing the seat geometry.[11] The posture prediction methodology was subsequently validated[12][13][14] Later on, the Predictive Dynamics method was created and used the same optimization technique with the addition of 3D laws of motion (equations of motion).[15] The Santos system includes many aspects of physiology modeling,[16] thermal, hand model,[17] grasp prediction,[18][19] gait analysis including stability,[20][15] mobility, suitability, survivability, maintainability, training,[21] and many other metrics typically used in the assessment of human performance for the Warfighter.[22]

Using this initial research and funding as a foundation, the VSR program continues to develop new technologies in digital human modeling and simulation, specifically with applications for the military, automotive, manufacturing, athletics, injury prediction, With over $60M in funding, the Santos simulation platform provides two key components that differentiates it among all other DHM systems: (1) Physics based[23] and (2) Predicts behavior.[24]

VSR's digital human model, Santos (R), stands at the center of its digital human modeling and simulation research.[25] The high-fidelity, biomechanically and biofidelic accurate musculoskeletal model incorporates 215 degrees of freedom, including the hand,[26] feet, and eyes. The dimensions of the skeleton are mutable, able to represent any anthropometric cross section. In addition, Santos includes a muscular system with the ability to predict muscle activation and muscle forces in real time, using a novel optimization-based methodology.[27][28][29] This method, developed over a period of eight years by the Virtual Soldier Research program is called Predictive Dynamics and published by a book[30] and a large number of papers.[31][32][33][34][35][36][6][37][38][39] Furthermore, the gradient based methodology used to solve for the motion was also replaced with an artificial intelligence neural network method.[40][41]

The mathematical model for the Santos skeleton was developed based on the Denavit-Hartenberg method for kinematic and dynamic analysis.[42] Optimization is used to determine postures and motions that are governed by various human performance measures (objective functions) and constrained by the restrictions imposed by the skeleton, the laws of physics, and the environment. The Santos simulation platform is being used by the US Military, industry (for example automotive industry),[43] and academia. The Virtual Soldier Research team transitioned a product from the Santos environment called Enhanced Technologies for the Optimization of Warfighter Load (ETOWL) funded by the Office of Naval Research (ONR) to the US Marines.[44] The product was later renamed as GruntSim.[45] This human modeling and simulation environment is now being used to study human factors[46][47] and ergonomics[48] in many applications.[49][50] This model includes not only Predictive Dynamics but also stability criteria called Zero Moment Point.[51] The use of the Santos Digital Human Model for example in assessing assembly issues in the design stage have been demonstrated[52] and for gait prediction as well.[53] Running for example,[54] which substantially more difficult to predict for a virtual human, was accomplished.[55]

The Santos simulation platform was developed from the ground up. Using the 215 DOF and based on the use of optimization based methods that enable cost functions to drive the motion, the numerical algorithm drives the motion to predict joint variables across time (also called joint profiles) and subject to a number of constraints. For example, predicting gait of any body type is now possible.[56] Similarly, any task can be modeled and simulated using this approach.[57][58] Xiang, Yujiang, Jasbir S. Arora, and Karim Abdel-Malek. "Hybrid predictive dynamics: a new approach to simulate human motion." Multibody System Dynamics 28.3 (2012): 199-224.[59]

The Santos system was also used to predict injury for various activities, particularly musculoskeletal injuries in athletics, military, manufacturing, and other domains.[60]

VSR research has led to the spin-off of a private company, Santos Human Inc.,[61] specifically focused on product development.

Who is Santos™?

Santos is the only physics-based[62][63] virtual human that stands at the center of the digital human modeling and simulation research at the University of Iowa and in use by the US Army and the US Marines. This high-fidelity, biofidelic, biomechanically and physiologically accurate musculoskeletal model was developed from the inside out by a large multidisciplinary team, and incorporates 215 degrees of freedom, including the hand, feet, and eyes. The dimensions of the skeleton are mutable, able to represent any anthropometric cross section. In addition, Santos includes a muscular system with the ability to predict muscle activation and muscle forces in real time, using a novel optimization-based methodology. The Santos system has been used in many applications.[64]

Over time, the Santos family has grown to incorporate a variety of different body scans to provide a range of models that include our female version, Sophia, and a broad array of different body shapes, types, and sizes.[65] Our research is currently being extended to allow multiple digital human models to interact with each other to complete tasks cooperatively.

Santos was built using state-of-the-art technologies adapted from robotics, Hollywood, and the game industry.[66] VSR research continues to grow in its dynamic capabilities, physiology, and intelligent behaviors through integration of Artificial Intelligence, design optimization, physics-based modeling, and advanced, multi-scale physiological models.[16]

The mathematical model for the Santos skeleton was developed based on the Denavit-Hartenberg method for kinematic and dynamic analysis. Optimization is used to determine postures and motions that are governed by various human performance measures (objective functions) and constrained by the restrictions imposed by the skeleton, the laws of physics, and the environment. The software must be as fast and efficient as possible in an effort to provide real-time simulations.

References

  1. Abdel-Malek, K., Yang, J., Kim, J.H., Beck, S., Swan, C., Frey-Law, L., Mathai, A., Murphy, C., Rahmatalla, S., and Arora, J. (2007). Development of the Virtual-Human Santos™. In V.G. Duffy (Ed.): Digital Human Modeling, HCII 2007, LNCS-4561, pp. 490-499.
  2. Yang, Jingzhou (James); Abdel-Malek, Karim (January 2009). "Human reach envelope and zone differentiation for ergonomic design". Human Factors and Ergonomics in Manufacturing 19 (1): 15–34. doi:10.1002/hfm.20135. ISSN 1090-8471. 
  3. Kim, Hyung Joo; Wang, Qian; Rahmatalla, Salam; Swan, Colby C.; Arora, Jasbir S.; Abdel-Malek, Karim; Assouline, Jose G. (2008-04-21). "Dynamic Motion Planning of 3D Human Locomotion Using Gradient-Based Optimization". Journal of Biomechanical Engineering 130 (3): 031002. doi:10.1115/1.2898730. ISSN 0148-0731. PMID 18532851. 
  4. Mi, Zan; Farrell, Kim; Abdel-Malek, Karim (2004-06-15). "Virtual Environment for Digital Human Simulation". SAE Technical Paper Series (Warrendale, PA: SAE International) 1. doi:10.4271/2004-01-2172. 
  5. Mi, Zan; Yang, Jingzhou (James); Abdel-Malek, Karim (July 2009). "Optimization-based posture prediction for human upper body". Robotica 27 (4): 607–620. doi:10.1017/s0263574708004992. ISSN 0263-5747. 
  6. 6.0 6.1 Abdel-Malek, Karim A.; Arora, Jasbir Singh (2013), "Posture Prediction and Optimization", Human Motion Simulation (Elsevier): pp. 41–68, doi:10.1016/b978-0-12-405190-4.00003-9, ISBN 978-0-12-405190-4 
  7. Johnson, Ross; Smith, Brian Lewis; Penmatsa, Rajeev; Marler, Tim; Abdel-Malek, Karim (2009-06-09). "Real-Time Obstacle Avoidance for Posture Prediction". SAE Technical Paper Series (Warrendale, PA: SAE International) 1. doi:10.4271/2009-01-2305. 
  8. 8.0 8.1 Abdel-Malek, Karim; Yu, Wei; Jaber, Mohamad; Duncan, Jerry (2001-06-26). "Realistic Posture Prediction for Maximum Dexterity". SAE Technical Paper Series (Warrendale, PA: SAE International) 1. doi:10.4271/2001-01-2110. 
  9. Marler, Timothy; Farrell, Kimberly; Kim, Joo; Rahmatalla, Salam; Abdel-Malek, Karim (2006-07-04). "Vision Performance Measures for Optimization-Based Posture Prediction". SAE Technical Paper Series (Warrendale, PA: SAE International) 1. doi:10.4271/2006-01-2334. 
  10. Xiang, Yujiang; Rahmatalla, Salam; Arora, Jasbir S.; Abdel-Malek, Karim (2011). "Enhanced optimisation-based inverse kinematics methodology considering joint discomfort". International Journal of Human Factors Modelling and Simulation 2 (1/2): 111. doi:10.1504/ijhfms.2011.041640. ISSN 1742-5549. 
  11. Kim, Joo H.; Yang, Jingzhou (James); Abdel-Malek, Karim (2009). "Multi-objective optimisation approach for predicting seated posture considering balance". International Journal of Vehicle Design 51 (3/4): 278. doi:10.1504/ijvd.2009.027957. ISSN 0143-3369. 
  12. Yang, Jingzhou; Rahmatalla, Salam; Marler, Tim; Abdel-Malek, Karim; Harrison, Chad (2007), "Validation of Predicted Posture for the Virtual Human SantosTM", Digital Human Modeling, Lecture Notes in Computer Science, 4561, Springer Berlin Heidelberg, pp. 500–510, doi:10.1007/978-3-540-73321-8_58, ISBN 978-3-540-73318-8 
  13. Marler, Timothy; Yang, Jingzhou; Rahmatalla, Salam; Abdel-Malek, Karim; Harrison, Chad (2007-06-12). "Validation Methodology Development for Predicted Posture". SAE Technical Paper Series (Warrendale, PA: SAE International) 1. doi:10.4271/2007-01-2467. 
  14. Rahmatalla, Salam; Xiang, Yujiang; Smith, Rosalind; Li, Jinzheng; Muesch, John; Bhatt, Rajan; Swan, Colby; Arora, Jasbir S. et al. (2008-06-17). "A Validation Protocol for Predictive Human Locomotion". SAE Technical Paper Series (Warrendale, PA: SAE International) 1. doi:10.4271/2008-01-1855. 
  15. 15.0 15.1 Chung, Hyun-Joon; Arora, Jasbir S.; Abdel-Malek, Karim; Xiang, Yujiang (2015-03-01). "Dynamic Optimization of Human Running With Analytical Gradients". Journal of Computational and Nonlinear Dynamics 10 (2). doi:10.1115/1.4027672. ISSN 1555-1415. 
  16. 16.0 16.1 Kim, Joo H.; Abdel-Malek, Karim; Yang, Jingzhou; Farrell, Kimberly; Nebel, Kyle (2005-06-14). "Optimization-Based Dynamic Motion Simulation and Energy Expenditure Prediction for a Digital Human". SAE Technical Paper Series (Warrendale, PA: SAE International) 1. doi:10.4271/2005-01-2717. 
  17. Pitarch, Esteban Peña; Yang, Jingzhou; Abdel-Malek, Karim (2005-06-14). "SANTOS™ Hand: A 25 Degree-of-Freedom Model". SAE Technical Paper Series (Warrendale, PA: SAE International) 1. doi:10.4271/2005-01-2727. 
  18. Goussous, F.; Marler, T.; Abdel-Malek, K. (March 2009). "A New Methodology for Human Grasp Prediction". IEEE Transactions on Systems, Man, and Cybernetics - Part A: Systems and Humans 39 (2): 369–380. doi:10.1109/tsmca.2008.2010090. ISSN 1083-4427. 
  19. Peña-Pitarch, Esteban; Yang, Jingzhou; Abdel-Malek, Karim (2009), "Virtual Human Hand: Grasping and Simulation", Digital Human Modeling, Lecture Notes in Computer Science (Springer Berlin Heidelberg) 5620: pp. 140–149, doi:10.1007/978-3-642-02809-0_16, ISBN 978-3-642-02808-3 
  20. Kim, Joo H.; Xiang, Yujiang; Bhatt, Rajankumar; Yang, Jingzhou; Chung, Hyun-Joon; Patrick, Amos; Arora, Jasbir S.; Abdel-Malek, Karim (2008-01-01). "Efficient ZMP Formulation and Effective Whole-Body Motion Generation for a Human-Like Mechanism". ASME 2008 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. 2: 32nd Mechanisms and Robotics Conference, Parts A and B. ASMEDC. pp. 1073–1084. doi:10.1115/detc2008-49925. ISBN 978-0-7918-4326-0. 
  21. Corrin, Amber (June 5, 2012). "Virtual soldier brings military training into the real world" (in en-US). https://defensesystems.com/articles/2012/06/04/virtual-soldier-research-future-troops.aspx. 
  22. Hariri, Mahdiar; Arora, Jasbir; Abdel-Malek, Karim (2012-08-12). "Optimization-Based Prediction of Aiming and Kneeling Military Tasks Performed by a Soldier". ASME 2012 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. 3: 38th Design Automation Conference, Parts A and B. American Society of Mechanical Engineers. pp. 661–671. doi:10.1115/detc2012-71166. ISBN 978-0-7918-4502-8. 
  23. Charis-Carlson, Jeff. "UI's virtual soldier program to help prevent injuries" (in en). https://www.press-citizen.com/story/news/education/university-of-iowa/2016/02/15/uis-virtual-solider-program-help-prevent-injuries/80423478/. 
  24. Navarro, Chantelle (24 February 2018). "UI Engineering department sees progress in virtual soldier, predicting injuries" (in english). https://www.kcrg.com/content/news/UI-Engineering-department-sees-progress-in-virtual-soldier-predicting-injuries-475022863.html. 
  25. About VSR | The University of Iowa
  26. Pena-Pitarch, E., Yang, J., and Abdel-Malek, K. (2005). Santos™ Hand: A 25-Degree-of-Freedom Model, SAE Technical Paper 2005-01-2727, doi:10.4271/2005-01-2727.
  27. Marler, R. Timothy; Arora, Jasbir S.; Yang, Jingzhou; Kim, Hyung-Joo; Abdel-Malek, Karim (2009-09-18). "Use of multi-objective optimization for digital human posture prediction". Engineering Optimization 41 (10): 925–943. doi:10.1080/03052150902853013. ISSN 0305-215X. 
  28. Abdel-Malek, Karim; Mi, Zan; Yang, Jingzhou; Nebel, Kyle (2006-07-03). "Optimization-based trajectory planning of the human upper body". Robotica 24 (6): 683–696. doi:10.1017/s0263574706002852. ISSN 0263-5747. 
  29. Yang, Jingzhou; Marler, R. Timothy; Beck, Steven; Abdel-Malek, Karim; Kim, Joo (March 2006). "Real-Time Optimal Reach-Posture Prediction in a New Interactive Virtual Environment". Journal of Computer Science and Technology 21 (2): 189–198. doi:10.1007/s11390-006-0189-3. ISSN 1000-9000. 
  30. Abdel-Malek, Karim (2013-05-30). Human motion simulation : predictive dynamics. Arora, Jasbir S.. Waltham, MA. ISBN 978-0-12-404601-6. OCLC 847948857. 
  31. Xiang, Yujiang; Arora, Jasbir S.; Abdel-Malek, Karim (2010-03-18). "Physics-based modeling and simulation of human walking: a review of optimization-based and other approaches". Structural and Multidisciplinary Optimization 42 (1): 1–23. doi:10.1007/s00158-010-0496-8. ISSN 1615-147X. 
  32. Xiang, Yujiang; Chung, Hyun-Joon; Kim, Joo H.; Bhatt, Rajankumar; Rahmatalla, Salam; Yang, Jingzhou; Marler, Timothy; Arora, Jasbir S. et al. (2009-08-21). "Predictive dynamics: an optimization-based novel approach for human motion simulation". Structural and Multidisciplinary Optimization 41 (3): 465–479. doi:10.1007/s00158-009-0423-z. ISSN 1615-147X. 
  33. Xiang, Yujiang; Arora, Jasbir S.; Rahmatalla, Salam; Abdel-Malek, Karim (2009-08-06). "Optimization-based dynamic human walking prediction: One step formulation". International Journal for Numerical Methods in Engineering 79 (6): 667–695. doi:10.1002/nme.2575. ISSN 0029-5981. Bibcode2009IJNME..79..667X. 
  34. Xiang, Yujiang; Arora, Jasbir S.; Chung, Hyun-Joon; Kwon, Hyun-Jung; Rahmatalla, Salam; Bhatt, Rajankumar; Abdel-Malek, Karim (2011-09-27). "Predictive simulation of human walking transitions using an optimization formulation". Structural and Multidisciplinary Optimization 45 (5): 759–772. doi:10.1007/s00158-011-0712-1. ISSN 1615-147X. 
  35. Kim, Joo H.; Yang, Jingzhou; Abdel-Malek, Karim (2008-01-10). "A novel formulation for determining joint constraint loads during optimal dynamic motion of redundant manipulators in DH representation". Multibody System Dynamics 19 (4): 427–451. doi:10.1007/s11044-007-9100-4. ISSN 1384-5640. 
  36. Abdel-Malek, Karim; Arora, Jasbir (2008-11-20), "Physics-Based Digital Human Modeling", Human Factors and Ergonomics (CRC Press): pp. 5–1–5–33, doi:10.1201/9781420063523.ch5, ISBN 978-0-8058-5646-0 
  37. Xiang, Yujiang; Arora, Jasbir S.; Abdel-Malek, Karim (June 2012). "3D Human Lifting Motion Prediction with Different Performance Measures". International Journal of Humanoid Robotics 09 (2): 1250012. doi:10.1142/s0219843612500120. ISSN 0219-8436. 
  38. Kim, Joo H.; Abdel-Malek, Karim; Yang, Jingzhou; Marler, Timothy; Nebel, Kyle (2005-01-01). "Lifting Posture Analysis in Material Handling Using Virtual Humans". ASME 2005 International Mechanical Engineering Congress and Exposition. Manufacturing Engineering and Materials Handling, Parts A and B. ASMEDC. pp. 1445–1453. doi:10.1115/imece2005-81801. ISBN 0-7918-4223-1. 
  39. Hariri, Mahdiar; Xiang, Yujiang; Chung, Hyun-Joon; Bhatt, Rajan; Arora, Jasbir; Abdel-Malek, Karim (2013-10-21). "Simulation and Prediction of the Motion of a Human in a Vertical Jumping Task". ASME 2013 Dynamic Systems and Control Conference. 1: Aerial Vehicles; Aerospace Control; Alternative Energy; Automotive Control Systems; Battery Systems; Beams and Flexible Structures; Biologically-Inspired Control and its Applications; Bio-Medical and Bio-Mechanical Systems; Biomedical Robots and Rehab; Bipeds and Locomotion; Control Design Methods for Adv. Powertrain Systems and Components; Control of Adv. Combustion Engines, Building Energy Systems, Mechanical Systems; Control, Monitoring, and Energy Harvesting of Vibratory Systems. American Society of Mechanical Engineers. doi:10.1115/dscc2013-4091. ISBN 978-0-7918-5612-3. 
  40. Bataineh, Mohammad; Marler, Timothy; Abdel-Malek, Karim; Arora, Jasbir (April 2016). "Neural network for dynamic human motion prediction". Expert Systems with Applications 48: 26–34. doi:10.1016/j.eswa.2015.11.020. ISSN 0957-4174. 
  41. Bataineh, Mohammad; Marler, Timothy; Abdel-Malek, Karim (2013), "Artificial Neural Network-Based Prediction of Human Posture", Digital Human Modeling and Applications in Health, Safety, Ergonomics, and Risk Management. Human Body Modeling and Ergonomics, Lecture Notes in Computer Science (Springer Berlin Heidelberg) 8026: pp. 305–313, doi:10.1007/978-3-642-39182-8_36, ISBN 978-3-642-39181-1 
  42. Denavit, J., & Hartenberg, R. S. (1955). A kinematic notation for lower-pair mechanisms based on matrices. Journal of Applied Mechanics, 77, 215–221.
  43. Yang, Jingzhou; Kim, Joo H.; Abdel-Malek, Karim; Marler, Timothy; Beck, Steven; Kopp, Gregory R. (July 2007). "A new digital human environment and assessment of vehicle interior design". Computer-Aided Design 39 (7): 548–558. doi:10.1016/j.cad.2006.11.007. ISSN 0010-4485. 
  44. "GruntSim, the Marines' new infantry simulator". https://popularmilitary.com/gruntsim-the-marines-new-infantry-simulator/. 
  45. (in en) GruntSim is a US Marines simulation for lightening the load, warfighter load, Predictive Dynamic, https://www.youtube.com/watch?v=RC8hseUmZDw, retrieved 2020-02-01 
  46. Abdel-Malek, Karim; Yu, Wei; Yang, Jingzhou; Nebel, Kyle (November 2004). "A mathematical method for ergonomic-based design: placement". International Journal of Industrial Ergonomics 34 (5): 375–394. doi:10.1016/j.ergon.2004.05.001. ISSN 0169-8141. 
  47. Department Of The Army Washington Dc (1987-05-08). Administration: Civilian Aides to the Secretary of the Army. Fort Belvoir, VA: Department of the Army Washingtong. doi:10.21236/ada401816. https://apps.dtic.mil/sti/tr/pdf/ADA401816.pdf. 
  48. Kim, Joo H.; Abdel-Malek, Karim; Mi, Zan; Nebel, Kyle (2004-06-15). "Layout Design using an Optimization-Based Human Energy Consumption Formulation". SAE Technical Paper Series (Warrendale, PA: SAE International) 1. doi:10.4271/2004-01-2175. 
  49. Xiang, Yujiang; Arora, Jasbir S.; Rahmatalla, Salam; Marler, Timothy; Bhatt, Rajankumar; Abdel-Malek, Karim (2010-01-21). "Human lifting simulation using a multi-objective optimization approach". Multibody System Dynamics 23 (4): 431–451. doi:10.1007/s11044-009-9186-y. ISSN 1384-5640. 
  50. Kim, Joo H.; Xiang, Yujiang; Yang, Jingzhou; Arora, Jasbir S.; Abdel-Malek, Karim (2010-03-31). "Dynamic motion planning of overarm throw for a biped human multibody system". Multibody System Dynamics 24 (1): 1–24. doi:10.1007/s11044-010-9193-z. ISSN 1384-5640. 
  51. Kim, J.H.; Xiang, Y.; Bhatt, R.M.; Yang, J.; Chung, H.-J.; Arora, J.S.; Abdel-Malek, K. (2009). "Generating Effective Whole-Body Motions of a Human-Like Mechanism with Efficient ZMP Formulation". International Journal of Robotics and Automation 24 (2). doi:10.2316/journal.206.2009.2.206-3235. ISSN 1925-7090. 
  52. Yang, Jingzhou; Pitarch, Esteban Pena; Kim, Joo; Abdel-Malek, Karim (2006-07-04). "Posture Prediction and Force/Torque Analysis for Human Hands". SAE Technical Paper Series (Warrendale, PA: SAE International) 1. doi:10.4271/2006-01-2326. 
  53. Kim, Hyung Joo; Horn, Emily; Arora, Jasbir S.; Abdel-Malek, Karim (2005-06-14). "An Optimization-Based Methodology to Predict Digital Human Gait Motion". SAE Technical Paper Series (Warrendale, PA: SAE International) 1. doi:10.4271/2005-01-2710. 
  54. Wang, Qian; Xiang, Yu-Jiang; Arora, Jasbir; Abdel-Malek, Karim (2007-04-23). "Alternative Formulations for Optimization-Based Human Gait Planning". 48th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference (Reston, Virginia: American Institute of Aeronautics and Astronautics). doi:10.2514/6.2007-1909. ISBN 978-1-62410-013-0. 
  55. Chung, Hyun-Joon; Xiang, Yujiang; Mathai, Anith; Rahmatalla, Salam; Kim, Joo; Marler, Timothy; Beck, Steve; Yang, Jingzhou et al. (2007-06-12). "A Robust Formulation for Prediction of Human Running". SAE Technical Paper Series (Warrendale, PA: SAE International) 1. doi:10.4271/2007-01-2490. 
  56. Xiang, Yujiang; Arora, Jasbir S.; Abdel-Malek, Karim (April 2011). "Erratum to "Optimization-based prediction of asymmetric human gait" [J. Biomech. 44 (4) (2011) 683–693]". Journal of Biomechanics 44 (6): 1217. doi:10.1016/j.jbiomech.2011.02.080. ISSN 0021-9290. 
  57. Kim, Joo H.; Abdel-Malek, Karim; Yang, Jingzhou; Marler, R. Timothy (2006). "Prediction and analysis of human motion dynamics performing various tasks". International Journal of Human Factors Modelling and Simulation 1 (1): 69. doi:10.1504/ijhfms.2006.011683. ISSN 1742-5549. 
  58. Xiang, Yujiang; Arora, Jasbir S.; Abdel-Malek, Karim (2008-05-14). "Optimization-based motion prediction of mechanical systems: sensitivity analysis". Structural and Multidisciplinary Optimization 37 (6): 595–608. doi:10.1007/s00158-008-0247-2. ISSN 1615-147X. 
  59. Xiang, Yujiang; Arora, Jasbir S.; Abdel-Malek, Karim (2012-03-28). "Hybrid predictive dynamics: a new approach to simulate human motion". Multibody System Dynamics 28 (3): 199–224. doi:10.1007/s11044-012-9306-y. ISSN 1384-5640. 
  60. Sultan, Sultan; Abdel-Malek, Karim; Arora, Jasbir; Bhatt, Rajan; Marler, Tim (2016-07-06), An Integrated Computational Simulation System for Injury Assessment, Advances in Intelligent Systems and Computing, 481, Springer International Publishing, pp. 23–34, doi:10.1007/978-3-319-41627-4_3, ISBN 978-3-319-41626-7 
  61. SantosHuman, Inc. | Predictive Human Model
  62. Abdel-Malek, Karim; Arora, Jasbir; Yang, Jingzhou; Marler, Timothy; Beck, Steve; Swan, Colby; Frey-Law, Laura; Mathai, Anith et al. (October 2006). "Santos: A Physics-Based Digital Human Simulation Environment". Proceedings of the Human Factors and Ergonomics Society Annual Meeting 50 (20): 2279–2283. doi:10.1177/154193120605002009. ISSN 1541-9312. 
  63. Abdel-Malek, Karim; Arora, Jasbir; Yang, Jingzhou (James); Marler, Timothy; Beck, Steve; Swan, Colby; Law, Laura Frey; Kim, Joo et al. (2009). "A physics-based digital human model". International Journal of Vehicle Design 51 (3/4): 324. doi:10.1504/ijvd.2009.027960. ISSN 0143-3369. 
  64. Abdel-Malek, Karim (July 2007). "Human modeling and applications special issue". Computer-Aided Design 39 (7): 539. doi:10.1016/j.cad.2007.04.001. ISSN 0010-4485. 
  65. Yang, Jingzhou; Marler, Tim; Kim, HyungJoo; Farrell, Kimberly; Mathai, Anith; Beck, Steven; Abdel-Malek, Karim; Arora, Jasbir et al. (2005-04-11). "Santos™: A New Generation of Virtual Humans". SAE Technical Paper Series (Warrendale, PA: SAE International) 1. doi:10.4271/2005-01-1407. 
  66. Yang, Jingzhou; Abdel-Malek, Karim; Farrell, Kim; Nebel, Kyle (2004-01-01). "The Iowa Interactive Digital-Human Virtual Environment". ASME 2004 International Mechanical Engineering Congress and Exposition. Manufacturing Engineering and Materials Handling Engineering. ASMEDC. pp. 1059–1067. doi:10.1115/imece2004-61791. ISBN 0-7918-4713-6.