Now showing items 1-20 of 1401

    • Long-distance in-situ methane detection using near-infrared light-induced thermo-elastic spectroscopy 

      Hu, Lien; Zheng, Chuantao; Zhang, Minghui; Zheng, Kaiyuan; Zheng, Jie; (2021)
      A wavelength-locked light-induced thermo-elastic spectroscopy (WL-LITES) gas sensor system was proposed for long-distance in-situ methane (CH4) detection using a fiber-coupled sensing probe. The wavelength-locked scheme was used to speed the sensor response without scanning the laser wavelength across the CH4 absorption line. A small-size piezoelectric ...
    • Systematic analysis of video-based pulse measurement from compressed videos 

      Nowara, Ewa M.; McDuff, Daniel; Veeraraghavan, Ashok (2021)
      Camera-based physiological measurement enables vital signs to be captured unobtrusively without contact with the body. Remote, or imaging, photoplethysmography involves recovering peripheral blood flow from subtle variations in video pixel intensities. While the pulse signal might be easy to obtain from high quality uncompressed videos, the signal-to-noise ...
    • A framework to identify structured behavioral patterns within rodent spatial trajectories 

      Donnarumma, Francesco; Prevete, Roberto; Maisto, Domenico; Fuscone, Simone; Irvine, Emily M.; (2021)
      Animal behavior is highly structured. Yet, structured behavioral patterns—or “statistical ethograms”—are not immediately apparent from the full spatiotemporal data that behavioral scientists usually collect. Here, we introduce a framework to quantitatively characterize rodent behavior during spatial (e.g., maze) navigation, in terms of movement ...
    • All-Optically Reconfigurable Plasmonic Metagrating for Ultrafast Diffraction Management 

      Schirato, Andrea; Mazzanti, Andrea; Proietti Zaccaria, Remo; Nordlander, Peter; Alabastri, Alessandro; (2021)
      Hot-electron dynamics taking place in nanostructured materials upon irradiation with fs-laser pulses has been the subject of intensive research, leading to the emerging field of ultrafast nanophotonics. However, the most common description of nonlinear interaction with ultrashort laser pulses assumes a homogeneous spatial distribution for the ...
    • NetDI: Methodology Elucidating the Role of Power and Dynamical Brain Network Features That Underpin Word Production 

      Yellapantula, Sudha; Forseth, Kiefer; Tandon, Nitin; Aazhang, Behnaam (2021)
      Canonical language models describe eloquent function as the product of a series of cognitive processes, typically characterized by the independent activation profiles of focal brain regions. In contrast, more recent work has suggested that the interactions between these regions, the cortical networks of language, are critical for understanding speech ...
    • A distinct population of heterogeneously color-tuned neurons in macaque visual cortex 

      Nigam, Sunny; Pojoga, Sorin; Dragoi, Valentin (2021)
      Color is a key feature of natural environments that higher mammals routinely use to detect food, avoid predators, and interpret social signals. The distribution of color signals in natural scenes is widely variable, ranging from uniform patches to highly nonuniform regions in which different colors lie in close proximity. Whether individual neurons ...
    • Colors of Single-Wall Carbon Nanotubes 

      Wei, Nan; Tian, Ying; Liao, Yongping; Komatsu, Natsumi; Gao, Weilu; (2021)
      Although single-wall carbon nanotubes (SWCNTs) exhibit various colors in suspension, directly synthesized SWCNT films usually appear black. Recently, a unique one-step method for directly fabricating green and brown films has been developed. Such remarkable progress, however, has brought up several new questions. The coloration mechanism, potentially ...
    • Domain-driven models yield better predictions at lower cost than reservoir computers in Lorenz systems 

      Pyle, Ryan; Jovanovic, Nikola; Subramanian, Devika; Palem, Krishna V.; Patel, Ankit B. (2021)
      Recent advances in computing algorithms and hardware have rekindled interest in developing high-accuracy, low-cost surrogate models for simulating physical systems. The idea is to replace expensive numerical integration of complex coupled partial differential equations at fine time scales performed on supercomputers, with machine-learned surrogates ...
    • Addressing indirect frequency coupling via partial generalized coherence 

      Young, Joseph; Homma, Ryota; Aazhang, Behnaam (2021)
      Distinguishing between direct and indirect frequency coupling is an important aspect of functional connectivity analyses because this distinction can determine if two brain regions are directly connected. Although partial coherence quantifies partial frequency coupling in the linear Gaussian case, we introduce a general framework that can address ...
    • Internet-Based Individualized Cognitive Behavioral Therapy for Shift Work Sleep Disorder Empowered by Well-Being Prediction: Protocol for a Pilot Study 

      Ito-Masui, Asami; Kawamoto, Eiji; Sakamoto, Ryota; Yu, Han; Sano, Akane; (2021)
      Background: Shift work sleep disorders (SWSDs) are associated with the high turnover rates of nurses, and are considered a major medical safety issue. However, initial management can be hampered by insufficient awareness. In recent years, it has become possible to visualize, collect, and analyze the work-life balance of health care workers with ...
    • Graded recruitment of pupil-linked neuromodulation by parametric stimulation of the vagus nerve 

      Mridha, Zakir; de Gee, Jan Willem; Shi, Yanchen; Alkashgari, Rayan; Williams, Justin; (2021)
      Vagus nerve stimulation (VNS) is thought to affect neural activity by recruiting brain-wide release of neuromodulators. VNS is used in treatment-resistant epilepsy, and is increasingly being explored for other disorders, such as depression, and as a cognitive enhancer. However, the promise of VNS is only partially fulfilled due to a lack of mechanistic ...
    • Tunable ultrasharp terahertz plasma edge in a lightly doped narrow-gap semiconductor 

      Ju, Xuewei; Hu, Zhiqiang; Huang, Feng; Wu, Haibin; Belyanin, Alexey; (2021)
      Plasma edges in metals typically occur in the visible range, producing characteristic colors of metals. In a lightly doped semiconductor, the plasma edge can occur in the terahertz (THz) frequency range. Due to low scattering rates and variable electron densities in semiconductors, such THz plasma edges can be extremely sharp and greatly tunable. ...
    • Inferring functional connectivity through graphical directed information 

      Young, Joseph; Neveu, Curtis L.; Byrne, John H.; Aazhang, Behnaam (2021)
      Objective. Accurate inference of functional connectivity is critical for understanding brain function. Previous methods have limited ability distinguishing between direct and indirect connections because of inadequate scaling with dimensionality. This poor scaling performance reduces the number of nodes that can be included in conditioning. Our goal ...
    • Time-domain terahertz spectroscopy in high magnetic fields 

      Baydin, Andrey; Makihara, Takuma; Peraca, Nicolas Marquez; Kono, Junichiro (2021)
      There are a variety of elementary and collective terahertz-frequency excitations in condensed matter whose magnetic field dependence contains significant insight into the states and dynamics of the electrons involved. Often, determining the frequency, temperature, and magnetic field dependence of the optical conductivity tensor, especially in high ...
    • Integrative Generalized Convex Clustering Optimization and Feature Selection for Mixed Multi-View Data 

      Wang, Minjie; Allen, Genevera I. (2021)
      In mixed multi-view data, multiple sets of diverse features are measured on the same set of samples. By integrating all available data sources, we seek to discover common group structure among the samples that may be hidden in individualistic cluster analyses of a single data view. While several techniques for such integrative clustering have been ...
    • Chemical Interface Damping of Surface Plasmon Resonances 

      Lee, Stephen A.; Link, Stephan; Smalley Curl Institute (2021)
      ConspectusMetal nanoparticles have been utilized for a vast amount of plasmon enhanced spectroscopies and energy conversion devices. Their unique optical properties allow them to be used across the UV–vis-NIR spectrum tuned by their size, shape, and material. In addition to utility in enhanced spectroscopy and energy/charge transfer, the plasmon ...
    • Nanoporous Metals: From Plasmonic Properties to Applications in Enhanced Spectroscopy and Photocatalysis 

      Koya, Alemayehu Nana; Zhu, Xiangchao; Ohannesian, Nareg; Yanik, A. Ali; Alabastri, Alessandro; (2021)
      The field of plasmonics is capable of enabling interesting applications in different wavelength ranges, spanning from the ultraviolet up to the infrared. The choice of plasmonic material and how the material is nanostructured has significant implications for ultimate performance of any plasmonic device. Artificially designed nanoporous metals (NPMs) ...
    • The Dual Graph Shift Operator: Identifying the Support of the Frequency Domain 

      Leus, Geert; Segarra, Santiago; Ribeiro, Alejandro; Marques, Antonio G. (2021)
      Contemporary data is often supported by an irregular structure, which can be conveniently captured by a graph. Accounting for this graph support is crucial to analyze the data, leading to an area known as graph signal processing (GSP). The two most important tools in GSP are the graph shift operator (GSO), which is a sparse matrix accounting for the ...
    • Dysglycemia in adults at risk for or living with non-insulin treated type 2 diabetes: Insights from continuous glucose monitoring 

      Barua, Souptik; Sabharwal, Ashutosh; Glantz, Namino; Conneely, Casey; Larez, Arianna; (2021)
      Background: Continuous glucose monitoring (CGM) has demonstrable benefits for people living with diabetes, but the supporting evidence is almost exclusively from White individuals with type 1 diabetes. Here, we have quantified CGM profiles in Hispanic/Latino adults with or at-risk of non-insulin treated type 2 diabetes (T2D). Methods: 100 participants ...
    • Line-of-sight and non-line-of-sight links for dispersive terahertz wireless networks 

      Ghasempour, Yasaman; Amarasinghe, Yasith; Yeh, Chia-Yi; Knightly, Edward; Mittleman, Daniel M. (2021)
      Despite the rapidly growing interest in exploiting millimeter and terahertz waves for wireless data transfer, the role of reflected non-line-of-sight (NLOS) paths in wireless networking is one of the least explored questions. In this paper, we investigate the idea of harnessing these specular NLOS paths for communication in directional networks at ...