Papers by TECV155 Aditya Wagh
Physical Review B
Orthoferrites (REFeO 3) containing rare-earth (RE) elements are 3D antiferromagnets (AFM) that ex... more Orthoferrites (REFeO 3) containing rare-earth (RE) elements are 3D antiferromagnets (AFM) that exhibit characteristic weak ferromagnetism originating due to slight canting of the spin moments and display a rich variety of spin reorientation transitions in the magnetic field (H)-temperature (T) parameter space. We present spin Hall magnetoresistance (SMR) studies on a b-plate (acplane) of crystalline Ho 0.5 Dy 0.5 FeO 3 |Pt hybrid at various T in the range, 11 to 300 K. In the room temperature Γ4(Gx, Ay, Fz) phase, the switching between two degenerate domains, Γ4(+Gx, +Fz) and Γ4(−Gx, −Fz) occurs at fields above a critical value, Hc ≈ 713 Oe. Under H > Hc, the angular dependence of SMR (α-scan) in the Γ4(Gx, Ay, Fz) phase yielded a highly skewed curve with a sharp change (sign-reversal) along with a rotational hysteresis around a-axis. This hysteresis decreases with an increase in H. Notably, at H < Hc, the α-scan measurements on the single domain, Γ4(±Gx, ±Fz) exhibited an anomalous sinusoidal signal of periodicity 360 deg. Low-T SMR curves (H = 2.4 kOe), showed a systematic narrowing of the hysteresis (down to 150 K) and a gradual reduction in the skewness (150 to 52 K), suggesting weakening of the anisotropy possibly due to the T-evolution of Fe-RE exchange coupling. Below 25 K, the SMR modulation showed an abrupt change around the c-axis, marking the presence of Γ2(Fx, Cy, Gz) phase. We have employed a simple Hamiltonian and computed SMR to examine the observed skewed SMR modulation. In summary, SMR is found to be an effective tool to probe magnetic anisotropy as well as a spin reorientation in Ho 0.5 Dy 0.5 FeO 3. Our spin-transport study highlights the potential of Ho 0.5 Dy 0.5 FeO 3 for future AFM spintronic devices.
Remote Sensing
The Laurentian Great Lakes, one of the world’s largest surface freshwater systems, pose a modelin... more The Laurentian Great Lakes, one of the world’s largest surface freshwater systems, pose a modeling challenge in seasonal forecast and climate projection. While physics-based hydrodynamic modeling is a fundamental approach, improving the forecast accuracy remains critical. In recent years, machine learning (ML) has quickly emerged in geoscience applications, but its application to the Great Lakes hydrodynamic prediction is still in its early stages. This work is the first one to explore a deep learning approach to predicting spatiotemporal distributions of the lake surface temperature (LST) in the Great Lakes. Our study shows that the Long Short-Term Memory (LSTM) neural network, trained with the limited data from hypothetical monitoring networks, can provide consistent and robust performance. The LSTM prediction captured the LST spatiotemporal variabilities across the five Great Lakes well, suggesting an effective and efficient way for monitoring network design in assisting the ML-b...
Real Time Image Processing on Single Board Computer
Imperial journal of interdisciplinary research, 2016
: This paper focus on real time image processing. Industrial image processing is a very important... more : This paper focus on real time image processing. Industrial image processing is a very important branch of scientific image processing and it is because of the rapid development of computer industry production and computer intelligence, as well as the corresponding developments in computer-aided image analysis . Image edge detection on single board computer is discussed in this paper. The application (GUI) Graphical User Interface was designed using Qt and Linux gcc Integrated Development Environment (IDE) for implementing image processing algorithm using Open Source Computer Vision Library (OpeCV). This developed software integrated in mobiles by the cross compilation of Qt and the OpeCV software for Linux Operating system.
This thesis has been approved in partial fulfillment of the requirements for the Degree of MASTER... more This thesis has been approved in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE in Mechanical Engineering.
Incorporating human factors considerations in the design of vehicular networks
Journal of Magnetism and Magnetic Materials, 2019
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Low temperature giant magnetocaloric effect in multiferroic GdMnO3single crystals
Journal of Physics D: Applied Physics, 2015
ABSTRACT Magnetocaloric (MC) properties of GdMnO3 single crystals are investigated using magnetic... more ABSTRACT Magnetocaloric (MC) properties of GdMnO3 single crystals are investigated using magnetic and magneto-thermal measurements. GdMnO3 exhibits a giant MC effect (isothermal change in magnetic entropy (−ΔSM) ~ 31 J (kg K)−1 at 7 K and adiabatic change in temperature ~10 K at 19 K for magnetic field variation 0-80 kOe). Complex interactions between 3d and 4f magnetic sublattices influence MC properties. The rare-earth antiferromagnetic ordering induces an inverse MC effect (positive ΔSM) along &#39;a&#39; and &#39;c&#39; axes whereas it&#39;s not seen along the &#39;b&#39; axis, revealing complex anisotropic magnetic ordering. The antiferromagnetic ordering possibly changes to ferromagnetic ordering at higher fields.
Human factors-aware service scheduling in Vehicular Cyber-Physical systems
2011 Proceedings IEEE INFOCOM, 2011
It is essential to consider drivers&amp;amp;#x27; perceptions and reactions when building Veh... more It is essential to consider drivers&amp;amp;#x27; perceptions and reactions when building Vehicular Cyber-Physical Systems (VCPS) since the effectiveness and efficiency of VCPS will largely depend on how drivers could benefit from such a system. This paper considers, for the first time, novel service scheduling problems from Human Factors (HF) standpoint by taking into consideration the following fact: a driver may
2011 IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS), 2011
Building effective Vehicular Cyber-Physical Systems (VCPS) to improve road safety is a non-trivia... more Building effective Vehicular Cyber-Physical Systems (VCPS) to improve road safety is a non-trivial challenge, especially when we examine how the driver benefits from the existing and proposed technologies in the presence of Human Factors (HF) related negative factors such as information overload, confusion, and distraction. In this paper, we address a humancentric data fusion problem in VCPS. To the best of our knowledge, this work is the first to apply HF to the data fusion problem, which has both theoretical value and practical implications. In particular, we present a new architecture by defining a distinct High-Level (HL) data fusion layer with HF considerations, that is placed between the safety applications on the VCPS and the human driver. A data fusion algorithm is proposed to fuse multiple messages (based on reaction time, message type, preferred evasive actions, severity of the hazards, etc) and to maximize the total utility of the messages. The algorithm is tested with real human drivers to demonstrate the potential benefit of incorporating such human-centric fusion in existing warning systems.
IEEE Transactions on Vehicular Technology, 2016
Transportation Cyber-Physical Systems (TCPS) requires simulation-based testing and evaluation due... more Transportation Cyber-Physical Systems (TCPS) requires simulation-based testing and evaluation due to the prohibitive cost of building realistic test beds. Given the trans-disciplinary nature of TCPS, various simulation models and frameworks have been proposed in civil engineering, computer science, and related fields. Traditionally, researchers in different areas have developed their own set of simulation tools, which provide limited capability for TCPS research. In recent years, we are witnessing a growing interest of combining two or more features of traditional simulators in order to capture the unique characteristics of TCPS. In this paper, we describe several mainstream simulation models used in transportation, communication and human factor studies in TCPS research. Moreover, we present our unique design and implementation of an Integrated Traffic Driving Network Simulator (ITDNS). Finally, we discuss future enhancements that will promote best simulation practices for TCPS research.
2013 Proceedings IEEE INFOCOM, 2013
We consider a promising application in Vehicular Cyber-Physical Systems (VCPS) called On-road Ad ... more We consider a promising application in Vehicular Cyber-Physical Systems (VCPS) called On-road Ad Delivery (OA D), where targeted advertisements are deli vered vi a roadsi de APs to attract commuters to nearby shops. Different from most existing works on VANETs which only focused on a single technical area, this work on OAD invol ves technical elements from human factors, cyber systems and trans portati on systems since a commuter's shopping decision depends on e.g. the attracti veness of the ads, the induced detour, and traffic condi tions on different routes. In this paper, we address a new optimizati on problem in OAD whose goal is to schedule ad messages and allocate a li mited amount of AP bandwi dth so as to maxi mize the system-wi de performance in terms of total realized utilities (TRU) of the deli vered ads. A number of efficient heuristics are proposed to deal with ad message scheduling and AP bandwi dth allocation. Besides largescale simulations, we also present a case study i n a more realistic scenario utilizing real traces collected from taxis in the ci ty of Shanghai. In additi on, we use a commercial traffic simul ator (PARAMICS) to show that our proposed solutions are also useful for traffic management in terms of bal ancing vehicul ar traffic and allevi ating congestion.
Journal of Computer Science and Technology, 2014
Cyber Transportation Systems (CTS) combine recent advance in information, communication and autom... more Cyber Transportation Systems (CTS) combine recent advance in information, communication and automation technologies in the field of road transport. CTS aim to provide advanced applications that improve road safety, traffic efficiency and sustainability of transport networks: Wireless communications allow vehicles and infrastructure to collaborate, and "Big Data" make it possible to monitor and predict the states of the systems. Subsequently, we could improve the control and management actions. This talk provides two examples of emerging applications in CTS. The first example explores the opportunity for cooperative vehicle and intersection control to contribute to a more sustainable transportation system. The second example proposes a new rideshare scheme for electric taxi fleet. I will also introduce our design and development of an integrated-traffic-driving-networking simulator (ITDNS). Such an ITDNS is not only useful for evaluating the proposed CTS applications that require simulation models from multiple disciplines, but also is an essential tool for studying human factor issues in the design, evaluation and optimization of other advanced CTS applications. Finally, I will conclude this talk with our ongoing project on vehicular sensing (i.e., using drivers' smart phone to collect data) and its future extensions. BIO Yunfei Hou is a PhD candidate in the Department of Computer Science and Engineering at the University at Buffalo (SUNY). His current research interests include applications in transportation cyber-physical systems, and cyber technologies for transportation engineering by considering human factors and driver perception. Recent projects span areas such as intersection management with connected vehicle technologies, electric taxi-sharing and taxi fleet dispatch, and on-road infotainment services. He has 13 refereed publications in premium conferences and journals such as INFOCOM, GLOBECOM, TRANSPORT RES C-EMER, and IEEE Trans. Veh. Technol. He receives a Best Digest Paper Award in ICCVE 2014. His research is supported by the NSF, DOT and NREL.
A Partial Reality Experimental System for Human-in-the-Loop Testing of Connected and Automated Vehicle Applications: Development, Validation and Applications
Lecture Notes in Mobility, 2014
This chapter describes a trans-disciplinary research initiative currently underway at the Univers... more This chapter describes a trans-disciplinary research initiative currently underway at the University at Buffalo, the State University of New York, which aims at developing next generation testing and evaluation platform for emerging Cyber Transportation Systems (CTS). Specifically, the work is developing an integrated traffic-driving-networking simulator (ITDNS), which allows for human-in-the-loop testing of Connected Vehicle (CV) and Automated Vehicle (AV) applications and their interactions. Following a brief discussion of ITDNS, its design rationale and unique advantages, the chapter proceeds to describe some of the on-going research designed to validate and extend ITDNS. The chapter also briefly describes our recent research which is taking advantage of the human-in-the-loop testing capabilities of ITDNS to evaluate a number of CV and AV applications such as eco-signals, Adaptive Cruise Control (ACC), and Co-operative, Integrated Vehicle Infrastructure Control (CIVIC).
Journal of the Korean Physical Society, 2013
Multiferroic materials are characterized by simultaneous magnetic and ferroelectric ordering maki... more Multiferroic materials are characterized by simultaneous magnetic and ferroelectric ordering making them good candidates for magneto-electrical applications. We conducted thermal expansion and magnetostriction measurements in magnetic fields up to 14 T on perovskitic GdMnO3 by highresolution capacitive dilatometry in an effort to determine all longitudinal and transversal components of the magnetostriction tensor. Below the ordering temperature TN = 42 K, i.e., within the different complex (incommensurate or complex) antiferromagnetic phases, lattice distortions of up to 100 ppm have been found. Although no change of the lattice symmetry occurs, the measurements reveal strong magneto-structural phenomena, especially in the incommensurate sinusoidal antiferromagnetic phase. A strong anisotropy of the magnetoelastic properties was found, in good agreement with the type and propagation vector of the magnetic structure. We demonstrate that our capacitive dilatometry can detect lattice expansion effects and changes of the dielectric permittivity simultaneously because the sample is housed inside the capacitor. A separation of both effects is possible by shielding the sample. Dielectric transitions could be detected by this method and compared to the critical values of H and T in the magnetic phase diagram. Dielectric changes measured at 1 kHz excitation frequency are detected in GdMnO3 at about 180 K, and between 10 K and 25 K in the canted antiferromagnetic structure which is characterized by a complex magnetic order on both the Gd-and Mn-sites.
Study of the Low Temperature Glassy Phase in Gd0.5Sr0.5MnO3 Single Crystals
Journal of Superconductivity and Novel Magnetism, 2010
ABSTRACT We have grown single crystals of Gd0.5Sr0.5MnO3 (GSMO50) using optical float zone method... more ABSTRACT We have grown single crystals of Gd0.5Sr0.5MnO3 (GSMO50) using optical float zone method. We report AC susceptibility measurements carried out on these single crystals at various frequencies in the range 42 to 10,000 Hz under the application of small AC magnetic field (∼170 mOe). The frequency dependence of the peak temperature follows a critical slowing down with exponent zν=1.13(4) as seen in the dynamical scaling analysis reported in the present paper. We observe that the glass-like phase in GSMO50 (∼ below 32 K) is very sluggish (spin flipping time τ 0=4×10−6 sec).
An investigation of first-order transition across charge ordered and ferromagnetic phases in Gd0.5Sr0.5MnO3single crystals by magnetic and magnetotransport studies
Journal of Physics: Condensed Matter, 2009
Gadolinium strontium manganite single crystals of the composition Gd(0.5)Sr(0.5)MnO(3) were grown... more Gadolinium strontium manganite single crystals of the composition Gd(0.5)Sr(0.5)MnO(3) were grown using the optical float zone method. We report here the magnetic and magnetotransport properties of these crystals. A large magnetoresistance ∼10(9)% was observed at 45 K under the application of a 110 kOe field. We have observed notable thermomagnetic anomalies such as open hysteresis loops across the broadened first-order transition between the charge order insulator and the ferromagnetic metallic phase while traversing the magnetic field-temperature (H-T) plane isothermally or isomagnetically. In order to discern the cause of these observed anomalies, the H-T phase diagram for Gd(0.5)Sr(0.5)MnO(3) is formulated using the magnetization-field (M-H), magnetization-temperature (M-T) and resistance-temperature (R-T) measurements. The temperature dependence of the critical field (i.e. H(up), the field required for transformation to the ferromagnetic metallic phase) is non-monotonic. We note that the non-monotonic variation of the supercooling limit is anomalous according to the classical concepts of the first-order phase transition. Accordingly, H(up) values below ∼20 K are unsuitable to represent the supercooling limit. It is possible that the nature of the metastable states responsible for the observed open hysteresis loops is different from that of the supercooled ones.
Integrated Traffic-Driving-Networking Simulator for the Design of Connected Vehicle Applications: Eco-Signal Case Study
Journal of Intelligent Transportation Systems, 2014
ABSTRACT This article first develops an integrated traffic-driving-networking simulator (ITDNS) i... more ABSTRACT This article first develops an integrated traffic-driving-networking simulator (ITDNS) intended for the design and evaluation of cyber transportation systems (CTS) and connected vehicle (CV) applications. The ITDNS allows a human driver to control a subject vehicle, in a virtual environment, that is capable of communicating with other vehicles and the infrastructure with CTS messages. The challenges associated with the integration of the three simulators, and how those challenges were overcome, are discussed. As an application example, an eco-signal system, which recommends the approach speed for vehicles approaching the intersection so as to minimize fuel consumption and emissions, was implemented in the ITDNS. Test drivers were then asked to virtually drive through a signalized corridor twice, one time with the eco-signal system in place and another without the system. Thanks to the human-in-the-loop component of ITDNS, the research was able to evaluate the likely benefits of the eco-signal system, while accounting for the response of human drivers to the recommended speed profiles. Moreover, the study compared the energy consumption and emission production rates of human-controlled vehicles’ approach trajectories to the rates associated with “idealistic” trajectories that may be attainable via vehicle automation. With respect to ITDNS, the study demonstrates the unique advantages of the simulator and the broad range of applications it can address. Regarding the eco-signal application example, preliminary results demonstrate the potential of the concept to result in tangible reductions of around 9% for energy consumption, 18% for carbon monoxide, and 25% for nitrogen oxides emissions. Moreover, the application eliminated hard accelerations and decelerations maneuvers, and thus may have an additional positive safety impact.
Negative differential resistance in Gd0.5Sr0.5MnO3: A consequence of Joule heating
Journal of Applied Physics, 2010
Page 1. Negative differential resistance in Gd0.5Sr0.5MnO3: A consequence of Joule heating Aditya... more Page 1. Negative differential resistance in Gd0.5Sr0.5MnO3: A consequence of Joule heating Aditya A. Wagh,1,a) PS Anil Kumar,1 HL Bhat,1,2 and Suja Elizabeth1 1Department of Physics, Indian Institute of Science, CV Raman ...
Toward Effective Service Scheduling for Human Drivers in Vehicular Cyber-Physical Systems
IEEE Transactions on Parallel and Distributed Systems, 2012
IEEE Journal on Selected Areas in Communications, 2013
Vehicular Cyber-Physical Systems (VCPS) provide human drivers with various services related to ro... more Vehicular Cyber-Physical Systems (VCPS) provide human drivers with various services related to road safety, and on-road infotainments. Since a service (message) delivery includes service transmission, service display and driver processing, many challenges arise due to limited network resources, possible preemption and contention between services for the display and non-negligible driver processing delay. In this paper, we address a new Driver-centric Service Delivery Problem (DSDP) from a cross-disciplinary resource allocation standpoint. Our goal is to deliver a number of services to a set of intended drivers in a given time period so as to maximize the system-wide performance in terms of total utility income (TUI) to drivers. We show that DSDP differs from all existing problems and is NP-Complete. A number of efficient heuristics are proposed to address several issues, including wireless transmission failure as well as distributed implementation of the multi-sender systems. Utilizing real traces collected from taxis in the city of Shanghai, we also present a case study in a more realistic scenario and conduct comprehensive simulations providing numerical results.
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Papers by TECV155 Aditya Wagh