Learning forward looking adaptation to dynamic payloads for quadruped locomotion via physics-informed neural networks
Oscar Youngquist and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2026.
[paper | supplementary | website]

Collaborative quadruped transportation in 3D terrain with constrained diffusion
Williard Joshua Jose, Li Chen, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2026.
[paper | supplementary | website]

Occlusion-robust relative pose estimation for multi-robot systems via geometric-aware diffusion matching
Suyoung Kang, Rishav Dutta, Peng Gao, Maggie Wigness, John G. Rogers, Donghyun Kim, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2026.
[paper | supplementary | website]

Collaborative planning with concurrent synchronization for operationally constrained UAV-UGV teams
Zihao Deng, Qianhuang Li, Peng Gao, Maggie Wigness, John G. Rogers, Donghyun Kim, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2026.
[paper | supplementary | website]

Subteaming and adaptive formation control for coordinated multi-robot navigation
Zihao Deng#, Peng Gao#, Williard Joshua Jose, Maggie Wigness, John Rogers, Brian Reily, Christopher Reardon, and Hao Zhang
Conference on Robot Learning (CoRL), 2025.
#Authors contributed equally to this paper

Non-overlap-aware egocentric pose estimation for collaborative perception in connected autonomy
Hong Huang, Dongkuan Xu, Hao Zhang, and Peng Gao
IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2025.

Coordinated multi-robot navigation with formation adaptation
Zihao Deng, Peng Gao, Williard Joshua Jose, Christopher M. Reardon, Maggie Wigness, John G. Rogers, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2025.
[paper | supplementary | website]

RINA: Rapid Introspective Neural Adaptation for out-of-distribution payload configurations on quadruped robots
Oscar Youngquist and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2025.
[paper | supplementary | website]

Self-reflective perceptual adaptation for robust ground navigation in unstructured off-road environments
Sriram Siva, Oscar Youngquist, Maggie Wigness, John G. Rogers, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2025.
[paper | supplementary | website]

Bandwidth-adaptive spatiotemporal correspondence identification for collaborative perception
Peng Gao, Williard Joshua Jose, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2025.

Depth estimation based on 3D Gaussian splatting siamese defocus
Jinchang Zhang, Ningning Xu, Hao Zhang, and Guoyu Lu
IEEE International Conference on Robotics and Automation (ICRA), 2025.

SiCP: Simultaneous individual and cooperative perception for 3D object detection in connected and automated vehicles
Deyuan Qu, Qi Chen, Tianyu Bai, Hongsheng Lu, Heng Fan, Hao Zhang, Song Fu, and Qing Yang
IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2024.

Learning for dynamic subteaming and voluntary waiting in heterogeneous multi-robot collaborative scheduling
Williard Joshua Jose and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2024.
*Finalist for Best Paper Award on Multi-Robot Systems
[paper | website]

Minimizing negative side effects in cooperative multi-agent systems using distributed coordination
Moumita Choudhury, Sandhya Saisubramanian, Hao Zhang, and Shlomo Zilberstein
International FLAIRS Conference (FLAIRS), 2024.

Self-reflective terrain-aware robot adaptation for consistent off-road ground navigation
Sriram Siva, Maggie Wigness, John Rogers, Long Quang, and Hao Zhang
International Journal of Robotics Research (IJRR), vol.43, no.7, 2024.

Minimizing negative side effects in cooperative multi-agent systems using distributed coordination
Zhe Chen, Li Chen, Hao Zhang, and Jianguo Zhao
International Conference on Autonomous Agents and Multi-Agent Systems (AAMAS), Extended Abstract, 2024.

Realizing desired shapes for a shape morphing manipulator
Zhe Chen, Li Chen, Hao Zhang, and Jianguo Zhao
IEEE International Conference on Soft Robotics (RoboSoft), Late Breaking Results, 2024.

SoftZoo: a soft robot co-design benchmark for locomotion in diverse environments
Tsun-Hsuan Wang, Pingchuan Ma, Andrew Everett Spielberg, Zhou Xian, Hao Zhang, Joshua B. Tenenbaum, Daniela Rus, and Chuang Gan
International Conference on Learning Representations (ICLR), 2023.

Collaborative scheduling with adaptation to failure for heterogeneous robot teams
Peng Gao, Sriram Siva, Anthony Micciche, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2023.

Compositional zero-shot learning for attribute-based object reference in human-robot interaction
Peng Gao#, Ahmed Jaafar#, Brian Reily, Christopher Reardon, and Hao Zhang
Conference on Robot Learning Workshop (CoRL-W), 2023.
#Authors contributed equally to this paper

Deep masked graph matching for correspondence identification in collaborative perception
Peng Gao#, Qingzhao Zhu#, Hongsheng Lu, Chuang Gan, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2023.
#Authors contributed equally to this paper.

Uncertainty-aware correspondence identification for collaborative perception
Peng Gao, Qingzhao Zhu, and Hao Zhang
Autonomous Robots (AuRo), vol.47, pp.635-648, 2023.

NAUTS: Negotiation for adaptation to unstructured terrain surfaces
Sriram Siva, Maggie Wigness, John Rogers, Long Quang, and Hao Zhang
IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2022.

Asynchronous collaborative localization by integrating spatiotemporal graph learning with model-based estimation
Peng Gao, Brian Reily, Rui Guo, Hongsheng Lu, Qingzhao Zhu, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2022.

Robot perceptual adaptation to environment changes for long-term human teammate following
Sriram Siva and Hao Zhang
International Journal of Robotics Research (IJRR), vol.41, no.7, 2022.

Enhancing consistent ground maneuverability by robot adaptation to complex off-road terrains
Sriram Siva, Maggie Wigness, John Rogers, and Hao Zhang
Conference on Robot Learning (CoRL), 2021.
Oral presentation (acceptance rate 6.5%).

An integrated approach to context-sensitive moral cognition in robot cognitive architectures
Ryan Blake Jackson#, Sihui Li#, Santosh Balajee Banisetty, Sriram Siva, Hao Zhang, Neil Dantam, and Tom Williams
IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2021.
#Authors contributed equally to this paper.
*Finalist for Best Paper Award on Cognitive Robotics

Bayesian deep graph matching for correspondence identification in collaborative perception
Peng Gao and Hao Zhang
Robotics Science and Systems (RSS), 2021.
[paper | spotlight talk]

Correspondence identification for collaborative multirobot perception under uncertainty
Peng Gao, Rui Guo, Hongsheng Lu, and Hao Zhang
Autonomous Robots (AuRo), vol.46, no.1, pp.5-20, 2021.

Multi-view sensor fusion by integrating model-based estimation and graph learning for collaborative object localization
Peng Gao, Rui Guo, Hongsheng Lu, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2021.

Adaptation to team composition changes for heterogeneous multi-robot sensor coverage
Brian Reily, Terran Mott, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2021.

Team assignment for heterogeneous multi-robot sensor coverage through graph representation learning
Brian Reily and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2021.

Edge-assisted cooperative perception in autonomous driving: a reflection on communication design
Ruozhou Yu, Dejun Yang, and Hao Zhang
ACM/IEEE Symposium on Edge Computing, 2021.

Multi-modal sensor fusion and selection for enhanced situational awareness
Brian Reily, Christopher Reardon, and Hao Zhang
Virtual, Augmented, and Mixed Reality (XR) Technology for Multi-Domain Operations, 2021.

Voxel-based representation learning for place recognition based on 3D point clouds
Sriram Siva*, Zachary Nahman*, and Hao Zhang
IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2020.
*Authors contributed equally to this paper.

Leading multi-agent teams to multiple goals while maintaining communication
Brian Reily, Christopher Reardon, and Hao Zhang
Robotics Science and Systems (RSS), 2020.
[paper | spotlight talk]

Real-time recognition of team behaviors by multisensory graph-embedded robot learning
Brian Reily, Peng Gao, Fei Han, Hua Wang, and Hao Zhang
International Journal of Robotics Research (IJRR), in press, 2021.

Robust real-time group activity recognition of robot teams
Lyujian Lu, Hua Wang, Brian Reily, and Hao Zhang
IEEE Robotics and Automation Letters (RA-L), vol.6, no.2, pp.2052-2059, 2021.

AI-enabled robotic NDE for structural damage assessment and repair
Xiaodong Shi, Anthony Olvera, Ciaron Hamilton, Jiaoyang Li, Lucas Utke, Andrew Petruska, Zhenzhen Yu, Yiming Deng, and Hao Zhang
Materials Evaluation, vol. 79, no. 7, 2021.

Regularized graph matching for correspondence identification under uncertainty in collaborative perception
Peng Gao, Rui Guo, Hongsheng Lu, and Hao Zhang
Robotics Science and Systems (RSS), 2020.
[paper | spotlight talk | dataset]

Representing multi-robot structure through multimodal graph embedding for the selection of robot teams
Brian Reily, Christopher Reardon, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2020.

Long-term place recognition through worst-case graph matching to integrate landmark appearances and spatial relationships
Peng Gao and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2020.

Simultaneous learning from human pose and object cues for real-time activity recognition
Brian Reily, Qingzhao Zhu, Christopher Reardon, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2020.

Correspondence identification in collaborative robot perception through maximin hypergraph matching
Peng Gao, Ziling Zhang, Rui Guo, Hongsheng Lu, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2020.

Visual reference of ambiguous objects for augmented reality-powered human-robot communication in a shared workspace
Peng Gao, Brian Reily, Savannah Paul, and Hao Zhang
International Conference on Virtual, Augmented and Mixed Reality (VAMR), invited paper, 2020.

Designing augmented reality visualizations for synchronized and time-dominant human-robot teaming
Savannah Paul, Christopher Reardon, Tom Williams, and Hao Zhang
SPIE Virtual, Augmented, and Mixed Reality (XR) Technology for Multi-Domain Operations, 2020.
[video presentation]

Long-term loop closure detection through visual-spatial information preserving multi-order graph matching
Peng Gao and Hao Zhang
AAAI Conference on Artificial Intelligence (AAAI), 2020.

Learning robust multilabel sample specific distances for identifying HIV-1 drug resistance
Lodewijk Brand, Xue Yang, Kai Liu, Saad Elbeleidy, Hua Wang and Hao Zhang
Journal of Computational Biology, vol.27, no.4, pp.655-672, 2020.

Robot adaptation to unstructured terrains by joint representation and apprenticeship learning
Sriram Siva, Maggie Wigness, John Rogers, and Hao Zhang
Robotics Science and Systems (RSS), 2019.

Robots can teach students with intellectual disabilities: Educational benefits of using robotic and augmented reality applications
Christopher Reardon, Hao Zhang, Rachel Wright, and Lynne Parker
IEEE Robotics & Automation Magazine (RAM), vol.26, no.2, pp.79-93, 2019.

Collaborative localization for occluded objects in connected vehicular platform
Rui Guo, Hongsheng Lu, Peng Gao, Ziling Zhang, and Hao Zhang
IEEE Vehicular Technology Conference (VTC), 2019.

AI-enabled robotic NDE for structural damage diagnosis and mapping
Xiaodong Shi, Zachary Nahman, Fares Alharbi, Ciaron Hamilton, Yiming Deng, and Hao Zhang
International Symposium on Applied Electromagnetics and Mechanics (ISEM), Poster Paper, 2019.
* Best Poster Award

Scalable representation learning for long-term augmented reality-based information delivery in collaborative human-robot perception
Fei Han, Sriram Siva, and Hao Zhang
International Conference on Virtual, Augmented and Mixed Reality (VAMR), invited paper, 2019.

Learning robust multi-label sample specific distances for identifying HIV-1 drug resistance
Lodewijk Brand, Xue Yang, Liu Kai, Saad Elbeleidy, Hua Wang, and Hao Zhang
International Conference on Research in Computational Molecular Biology (RECOMB), 2019.

A comparative analysis of visual-inertial SLAM for assisted wayfinding of the visually impaired
He Zhang, Lingqiu Jin, Hao Zhang, and Cang Ye
IEEE Winter Conference on Applications of Computer Vision (WACV), 2019.

Visual place recognition via robust l2-norm distance based holism and landmark integration
Kai Liu, Hua Wang, Fei Han, and Hao Zhang
AAAI Conference on Artificial Intelligence (AAAI), 2019.

Shaping of shared autonomous solutions with minimal interaction
Christopher Reardon, Hao Zhang, and Jonathan Fink
Frontiers in Neurorobotics, vol.12, no.54, 2018.

Learning of holism-landmark graph embedding for place recognition in long-term autonomy
Fei Han, Saad Elbeleidy, Hua Wang, Cang Ye, and Hao Zhang
IEEE Robotics and Automation Letters (RA-L), vol.3, no.4, pp.3669-3676, 2018.

Learning of integrated holism-landmark representations for long-term loop closure detection
Fei Han, Hua Wang, and Hao Zhang
AAAI Conference on Artificial Intelligence (AAAI), 2018.

Learning multi-instance enriched image representation via non-greedy simultaneous l1-norm minimization and maximization
Kai Liu, Hua Wang, Feiping Nie, and Hao Zhang
IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2018.

Robot understanding of human intents in gesture-based interaction
Fei Han, Christopher Reardon, Cang Ye, and Hao Zhang
Workshop of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2017.

Metacognitive reasoning of perceptual inconsistency for illusion detection
Sriram Siva and Hao Zhang
Workshops on Adversarial Robotics at RSS, 2018.

Robot adaptation to environment changes in long-term autonomy
Sriram Siva and Hao Zhang
Workshops on Robot Teammates Operating in Dynamic, Unstructured Environments (RT-DUNE) at ICRA, 2018.

Team intent understanding through latent representation learning for underground search and rescue
Fei Han and Hao Zhang
Workshops on Robot Teammates Operating in Dynamic, Unstructured Environments (RT-DUNE) at ICRA, 2018.

Omnidirectional multisensory perception fusion for long-term place recognition
Sriram Siva and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2018.

Optimizing autonomous surveillance route solutions from minimal human-robot interaction
Christopher Reardon, Fei Han, Hao Zhang, and Jonathan Fink
IEEE International Symposium on Safety, Security, and Rescue Robotics (SSRR), 2017.

Planning-based workflow modeling for AR-enabled automated task guidance
Fei Han, Jiayi Liu, William Hoff, and Hao Zhang
International Symposium on Mixed and Augmented Reality (ISMAR), Poster Paper, 2017.

Skeleton-based bio-inspired human activity prediction for real-time human-robot interaction
Brian Reily, Fei Han, Lynne E. Parker, and Hao Zhang
Autonomous Robots (AuRo), vol.42, no.6, pp 1281-1298, 2018.

Sequence-based sparse optimization methods for long-term loop closure detection in visual SLAM
Fei Han, Hua Wang, Guoquan Huang, and Hao Zhang
Autonomous Robots (AuRo), vol.42, no.7, pp.1323-1335, 2018.

Sequence-based multimodal apprenticeship learning for robot perception and decision making
Fei Han, Xue Yang, Yu Zhang, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2017.

Simultaneous feature and body-part learning for real-time robot awareness of human behaviors
Fei Han, Xue Yang, Christopher Reardon, Yu Zhang, and Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2017.

Minimum uncertainty latent variable models for robot recognition of sequential human activities
Fei Han, Christopher M. Reardon, Lynne Parker, Hao Zhang
IEEE International Conference on Robotics and Automation (ICRA), 2017.

SRAL: Shared representative appearance learning for long-term visual place recognition
Fei Han, Xue Yang, Yiming Deng, Mark Rentschler, Dejun Yang, and Hao Zhang
IEEE Robotics and Automation Letters (RA-L), vol.26, no.3, pp.1172-1179, 2017.

Space-time representation of people based on 3d skeletal data: A review
Fei Han, Brian Reily, William Hoff, and Hao Zhang
Computer Vision and Image Understanding (CVIU), vol.158, pp.85-105, 2017.

Real-time gymnast detection and performance analysis with a portable 3D camera
Brian Reily, Hao Zhang, and William Hoff
Computer Vision and Image Understanding (CVIU), vol.159, pp.154-163, 2017.

Data-driven fault detection via sparse multisensory learning
Fei Han, Christopher Dreyer, Thomas Jones, Rob Kelso, James Thomas, and Hao Zhang
AIAA Annual Technical Symposium (ATS), 2016.

Learning object and state models for AR task guidance
William Hoff and Hao Zhang
International Symposium on Mixed and Augmented Reality (ISMAR), Poster Paper, 2016.

A unified representation for robot learning of action labels and motion trajectories from internet 3D human skeletal data
Chi Zhang, Hao Zhang, Rui Guo, and Lynne E. Parker
IEEE International Symposium on Robot and Human Interactive Communication (RO-MAN), 2016.

Life-long place recognition by shared representative appearance learning
Fei Han, Xue Yang, Yiming Deng, Mark Rentschler, Dejun Yang, and Hao Zhang
Workshops in conjunction with Robotics: Science and Systems (RSS), 2016.

Robust multimodal sequence-based loop closure detection via structured sparsity
Hao Zhang, Fei Han, and Hua Wang
Robotics: Science and Systems (RSS), 2016.
* Best Paper Finalist.

Enforcing template representability and temporal consistency for adaptive sparse tracking
Xue Yang, Fei Han, and Hao Zhang
International Joint Conference on Artificial Intelligence (IJCAI), 2016.

SRAC: Self-reflective risk-aware artificial cognitive models for robot response to human activities
Hao Zhang, Christopher Reardon, Fei Han, and Lynne E. Parker
IEEE International Conference on Robotics and Automation (ICRA), 2016.

Drosophila gene expression pattern annotations via multi-instance biological relevance learning
Hua Wang, Cheng Deng, Hao Zhang, Xinbo Gao, and Heng Huang
AAAI Conference on Artificial Intelligence (AAAI), 2016.

CoDe4D: color-depth local spatio-temporal features for human activity recognition from RGB-D videos
Hao Zhang and Lynne E. Parker
IEEE Transactions on Circuits and Systems for Video Technology (TCSVT), vol.26, no.3, pp.541-555, 2016.

Feature space decomposition for effective robot adaptation
Chi Zhang, Hao Zhang and Lynne E. Parker
IEEE International Conference on Intelligent Robots and Systems (IROS), 2015.

Bio-inspired predictive orientation decomposition of skeleton trajectories for real-time human activity prediction
Hao Zhang and Lynne E. Parker
IEEE International Conference on Robotics and Automation (ICRA), 2015.

Adaptive human-centered representation for activity recognition of multiple individuals from 3D point cloud sequences
Hao Zhang, Christopher Reardon, Chi Zhang, and Lynne E. Parker
IEEE International Conference on Robotics and Automation (ICRA), 2015.

Response prompting for intelligent robot instruction of students with intellectual disabilities
Christopher Reardon, Hao Zhang, Rachel Wright, and Lynne E. Parker
IEEE International Symposium on Robot and Human Interactive Communication (RO-MAN), 2015.
* Finalist of RSJ/KROS Distinguished Interdisciplinary Research Award.

Feature space decomposition for autonomous robot adaptation in programming by demonstration
Chi Zhang, Hao Zhang, and Lynne E. Parker
Workshops in conjunction with IEEE International Conference on Robotics and Automation (ICRA), 2015.

Fuzzy temporal segmentation and probabilistic recognition of continuous human daily activities
Hao Zhang, Wenjun Zhou, and Lynne E. Parker
IEEE Transactions on Human-Machine Systems (THMS), vol.45, no.5, pp.598-611, 2015.

Correlation range query for effective recommendations
Wenjun Zhou and Hao Zhang
World Wide Web (WWW), vol. 18, no. 3, pp 709-729, 2015.

Simplex-based 3D spatio-temporal feature description for action recognition
Hao Zhang, Wenjun Zhou, Christopher Reardon, and Lynne E. Parker
IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2014.

CORE: A dataset of critical objects for response to emergency
Ahmed A. Ambarak, John Steele, and Hao Zhang
IEEE International Symposium on Safety, Security, and Rescue Robotics (SSRR), Late Breaking Report, 2015.

Fuzzy segmentation and recognition of continuous human activities
Hao Zhang, Wenjun Zhou, and Lynne E. Parker
IEEE International Conference on Robotics and Automation (ICRA), 2014.

Zebrafish larva locomotor activity analysis using machine learning techniques
Hao Zhang, Scott C. Lenaghan, Michelle H. Connolly, and Lynne E. Parker
IEEE International Conference on Machine Learning and Applications (ICMLA), 2013.

Approximate l-fold cross-validation with least squares SVM and kernel ridge regression
Richard Edwards, Hao Zhang, and Lynne E. Parker
IEEE International Conference on Machine Learning and Applications (ICMLA), 2013.

Correlation range query
Wenjun Zhou and Hao Zhang
International Conference on Web-Age Information Management (WAIM), 2013.
* Best Paper Award.

Real-time multiple human perception with color-depth cameras on a mobile robot
Hao Zhang, Christopher Reardon, and Lynne E. Parker
IEEE Transactions on Cybernetics (TCYB), vol. 43, no. 5, pp. 1429-1441, Oct. 2013.

Monitoring the environmental impact of TiO2 nanoparticles using a plant-based sensor network
Scott C. Lenaghan, Yuanyuan Li, Hao Zhang, Jason N. Burris, C. Neal Stewart, Lynne E. Parker, and Mingjun Zhang
IEEE Transactions on Nanotechnology (TNANO), vol.12, no.2, pp.182-189, 2013.

Regularized probabilistic latent semantic analysis with continuous observations
Hao Zhang, Richard Edwards, and Lynne E. Parker
IEEE International Conference on Machine Learning and Applications (ICMLA), 2012.

HPC usage behavior analysis and performance estimation with machine learning techniques
Hao Zhang, Haihang You, Bilel Hadri, and Mark Fahey
International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA), 2012.

Comprehensive workload analysis and modeling of a petascale supercomputer
Haihang You and Hao Zhang
Workshop on Job Scheduling Strategies for Parallel Processing (JSSPP) in conjunction with IPDPS, 2012.

4-Dimensional local spatio-temporal features for human activity recognition
Hao Zhang, and Lynne E. Parker
IEEE International Conference on Intelligent Robots and Systems (IROS), 2011.

A novel method for background suppression in millimeter-wave traffic radar sensor
Hao Zhang, Wen Yu, and Xiaowei Sun
IEEE International Conference on Intelligent Transportation Systems (ITSC), 2008.

Adaptive traffic lane detection based on normalized power accumulation
Hao Zhang, Wen Yu, and Xiaowei Sun
IEEE International Conference on Intelligent Transportation Systems (ITSC), 2008.

Background power spectrum recognition in applications of millimeter wave flow detection radar
Hao Zhang, Wen Yu, and Xiaowei Sun
Journal of Infrared and Millimeter Waves (JIMW), vol. 27, no. 6, 2008.