scholarly journals Nonlinearity- and dispersion- less integrated optical time magnifier based on a high-Q SiN microring resonator

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Arijit Misra ◽  
Stefan Preußler ◽  
Linjie Zhou ◽  
Thomas Schneider
Keyword(s):  
Cost Effective ◽  
Microring Resonator ◽  
Single Shot ◽  
Analog To Digital ◽  
Optical Signals ◽  
Stretching Factor ◽  
Integrated Cost ◽  
The Time Domain ◽  
Application Fields ◽  
Time Magnification

Abstract The ability to measure optical signals with fast dynamics is of significant interest in many application fields. Usually, single-shot measurements of non-periodic signals can be enabled by time magnification methods. Like an optical lens in the spatial domain, a time magnifier, or a time lens, stretches a signal in the time domain. This stretched signal can then be further processed with low bandwidth photonics and electronics. For a robust and cost-effective measurement device, integrated solutions would be especially advantageous. Conventional time lenses require dispersion and nonlinear optical effects. Integration of a strong dispersion and nonlinearities is not straightforward on a silicon photonics platform and they might lead to signal distortions. Here we present a time magnifier based on an integrated silicon nitride microring resonator and frequency-time coherence optical sampling, which requires neither a dispersion, nor a nonlinearity. Sampling of signals with up to 100 GHz bandwidth with a stretching factor of more than 100 is achieved using low bandwidth measurement equipment. Nevertheless, with already demonstrated integrated 100 GHz modulators, the method enables the measurement of signals with bandwidths of up to 400 GHz. Since amplitude and phase can be sampled, a combination with the spectrum slicing method might enable integrated, cost-effective, small-footprint analog-to-digital converters, and measurement devices for the characterization of single irregular optical signals with fast dynamics and bandwidths in the THz range.

scholarly journals Accurate Power-Efficient Format-Scalable Multi-Parallel Optical Digital-to-Analogue Conversion

Photonics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 38
Author(s):  
Moshe Nazarathy ◽  
Ioannis Tomkos
Keyword(s):  
Energy Efficiency ◽  
Direct Detection ◽  
Coherent Detection ◽  
Performance Limits ◽  
Optical Modulators ◽  
Analog To Digital ◽  
Power Efficient ◽  
Optical Signals ◽  
Digital To Analog Converters ◽  
Optical Analog

In optical transmitters generating multi-level constellations, optical modulators are preceded by Electronic Digital-to-Analog-Converters (eDAC). It is advantageous to use eDAC-free Optical Analog to Digital Converters (oDAC) to directly convert digital bitstreams into multilevel PAM/QAM optical signals. State-of-the-art oDACs are based on Segmented Mach-Zehnder-Modulators (SEMZM) using multiple modulation segments strung along the MZM waveguides to serially accumulate binary-modulated optical phases. Here we aim to assess performance limits of the Serial oDACs (SEMZM) and introduce an alternative improved Multi-Parallel oDAC (MPoDAC) architecture, in particular based on arraying multiple binary-driven MZMs in parallel: Multi-parallel MZM (MPMZM) oDAC. We develop generic methodologies of oDAC specification and optimization encompassing both SEMZM and MPMZM options in Direct-Detection (DD) and Coherent-Detection (COH) implementations. We quantify and compare intrinsic performance limits of the various serial/parallel DD/COH subclasses for general constellation orders, comparing with the scant prior-work on the multi-parallel option. A key finding: COH-MPMZM is the only class synthesizing ‘perfect’ (equi-spaced max-full-scale) constellations while maximizing energy-efficiency-SEMZM/MPMZM for DD are less accurate when maximal energy-efficiency is required. In particular, we introduce multiple variants of PAM4|8 DD and QAM16|64 COH MPMZMs, working out their accuracy vs. energy-efficiency-and-complexity tradeoffs, establishing their format-reconfigurability (format-flexible switching of constellation order and/or DD/COH).

scholarly journals Testing a community-based distribution approach to reproductive health service delivery in Senegal (a study of community agents in Kébémer)

2004 ◽  
Keyword(s):  
Rural Communities ◽  
Reproductive Health ◽  
Service Delivery ◽  
Social Action ◽  
Rural Areas ◽  
Cost Effective ◽  
Health Service Delivery ◽  
Reproductive Health Services ◽  
Community Based ◽  
Integrated Cost

The Division of Reproductive Health (DSR) of the Senegal Ministry of Health and Social Action, in partnership with the Population Council’s FRONTIERS in Reproductive Health program and Management Sciences for Health (MSH), conducted a study to test and compare three ways of providing reproductive health services to rural communities in the Kébémer district of Senegal in terms of their effectiveness, cost, and cost-effectiveness. FRONTIERS and MSH collaborated with the DSR to design the interventions, MSH supported the DSR in implementing the interventions, and FRONTIERS undertook the evaluation. This study, funded by USAID, responded to the recommendations of a 1999 workshop, organized by FRONTIERS and the DSR, on the community-based distribution (CBD) approach, which defined alternative CBD models appropriate for Senegal. The DSR sees the development of community-based service delivery models as essential for the future of health care in Senegal. As noted in this report, the general objective of the study was to contribute to the development of an integrated cost-effective program to increase the accessibility and availability of reproductive health information and services in rural areas of Senegal.

Edge Artificial Intelligence: A Multi-Camera Video Surveillance Application

2021 ◽  
Author(s):  
Daniele Berardini ◽  
Adriano Mancini ◽  
Primo Zingaretti ◽  
Sara Moccia
Keyword(s):  
Artificial Intelligence ◽  
Real Time ◽  
Video Surveillance ◽  
Cost Effective ◽  
Fast Response ◽  
Video Stream ◽  
Single Shot ◽  
Central Unit ◽  
Surveillance Video ◽  
People Detection

Abstract Nowadays, video surveillance has a crucial role. Analyzing surveillance videos is, however, a time consuming and tiresome procedure. In the last years, artificial intelligence paved the way for automatic and accurate surveillance-video analysis. In parallel to the development of artificial-intelligence methodologies, edge computing is becoming an active field of research with the final goal to provide cost-effective and real time deployment of the developed methodologies. In this work, we present an edge artificial intelligence application to video surveillance. Our approach relies on a set of four IP cameras, which acquire video frames that are processed on the edge using the NVIDIA® Jetson Nano. A state-of-the-art deep-learning model, called Single Shot multibox Detector (SSD) MobileNetV2 network, is used to perform object and people detection in real-time. The proposed infrastructure obtained an inference speed of ∼10.0 Frames per Second (FPS) for each parallel video stream. These results prompt the possibility of translating our work into a real word scenario. The integration of the presented application into a wider monitoring system with a central unit could bring benefits to the overall infrastructure. Indeed our application could send only video-related high-level information to the central unit, allowing it to combine information with data coming from other sensing devices without unuseful data overload. This would ensure a fast response in case of emergency or detected anomalies. We hope this work will contribute to stimulate the research in the field of edge artificial intelligence for video surveillance.

scholarly journals UAV Landing Using Computer Vision Techniques for Human Detection

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 613
Author(s):  
David Safadinho ◽  
João Ramos ◽  
Roberto Ribeiro ◽  
Vítor Filipe ◽  
João Barroso ◽  
...  
Keyword(s):  
Computer Vision ◽  
Tall Buildings ◽  
Landing Site ◽  
Cost Effective ◽  
Human Detection ◽  
Raspberry Pi ◽  
Single Shot ◽  
Irregular Terrain ◽  
Effective System ◽  
Satellite Signal

The capability of drones to perform autonomous missions has led retail companies to use them for deliveries, saving time and human resources. In these services, the delivery depends on the Global Positioning System (GPS) to define an approximate landing point. However, the landscape can interfere with the satellite signal (e.g., tall buildings), reducing the accuracy of this approach. Changes in the environment can also invalidate the security of a previously defined landing site (e.g., irregular terrain, swimming pool). Therefore, the main goal of this work is to improve the process of goods delivery using drones, focusing on the detection of the potential receiver. We developed a solution that has been improved along its iterative assessment composed of five test scenarios. The built prototype complements the GPS through Computer Vision (CV) algorithms, based on Convolutional Neural Networks (CNN), running in a Raspberry Pi 3 with a Pi NoIR Camera (i.e., No InfraRed—without infrared filter). The experiments were performed with the models Single Shot Detector (SSD) MobileNet-V2, and SSDLite-MobileNet-V2. The best results were obtained in the afternoon, with the SSDLite architecture, for distances and heights between 2.5–10 m, with recalls from 59%–76%. The results confirm that a low computing power and cost-effective system can perform aerial human detection, estimating the landing position without an additional visual marker.

scholarly journals A Buckling Flexure-Based Force-Limiting Mechanism

2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Jonathan Slocum ◽  
Kenneth Kamrin ◽  
Alexander Slocum
Keyword(s):  
Finite Element ◽  
Design Methodology ◽  
Structural Model ◽  
Cost Effective ◽  
Element Model ◽  
Single Shot ◽  
Excessive Force ◽  
Molding Machine ◽  
Preliminary Model ◽  
Wide Range

A force-limiting buckling flexure has been created which can be used in a wide range of applications where excessive force from an implement can cause harm or damage. The buckling flexure is monolithic, contains no electronics, and can be manufactured using a single shot in an injection molding machine, making it cost effective. In this paper, the design of the flexure is applied to a force-limiting toothbrush as a design study to show its application in a real-world technology. An overview of the buckling flexure is presented, and a structural model is presented to predict when the flexure will elastically buckle. Flexures of different geometries were tested and buckled. The data show that the model can predict buckling of the flexure with an error of 20.84%. A finite element model was also performed which predicts buckling of the flexure within an error of 25.35%. Furthermore, a preliminary model is presented which enables the design of the buckling beam’s displacement, such that the total breakaway deformation can be maximized, making sensing the sudden deformation easier to detect. As part of the application of the buckling flexure, an ergonomic, injection moldable toothbrush was created with the flexure built into the neck of the brush. When the user applies too much force while brushing, the flexure gives way and alerts the user when they have applied too much force; when the user lets off the force, the brush snaps back to its original shape. This design methodology is generalized and can be utilized in other force limited applications where an injection-moldable, pre-set force, and purely mechanical breakaway device is desired.

Modified duobinary modulation of optical signals generated by silicon‐based microring resonator

2019 ◽  
Vol 61 (6) ◽  
pp. 1661-1668 ◽  
Author(s):  
Iraj Sadegh Amiri ◽  
Satish Addanki ◽  
Arumugam Sampathkumar ◽  
Vigneswaran Dhasarathan ◽  
Preecha Yupapin
Keyword(s):  
Microring Resonator ◽  
Optical Signals ◽  
Silicon Based

scholarly journals Fiber optically integrated cost-effective spectrometer for optical coherence tomography

2014 ◽  
Author(s):  
Stefan Remund ◽  
Anke Bossen ◽  
Xianfeng Chen ◽  
Ling Wang ◽  
Lin Zhang ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Cost Effective ◽  
Optical Coherence ◽  
Integrated Cost

Providing Configurability and Plug-and-Play Capability to Simple Sensors: A Step towards Smart Sensors for Smart Factories

2012 ◽  
Vol 162 ◽  
pp. 597-606 ◽  
Author(s):  
Mircea Murar ◽  
Stelian Brad
Keyword(s):  
Manufacturing Systems ◽  
Cost Effective ◽  
Digital Data ◽  
Sensor System ◽  
Data Conversion ◽  
Plug And Play ◽  
Analog To Digital ◽  
Configuration Data ◽  
Smart Factories ◽  
Distributed Manufacturing Systems

A modality to boost up the abilities of simple sensors for providing extended configurability options and plug-and-play capability along with great scalability, integrability, rapid customization and modularity is reported in this paper. An embedded architecture that requires both electronic and software designs is employed for expanding sensor capability. Self-integration, configuration, data computation from the sensor, analog-to-digital data conversion and data processing relative to configuration options are investigated. Based on the approach proposed, an embedded sensor-system, consisting of a network of microcontrollers and sensors capable to respond to configurability and fast integrability requirements, is built and tested within this research. Tests have shown the smart sensor-system is functional, feasible, cost-effective, easy-to-use and highly reconfigurable. Integration of such sensors within reconfigurable, autonomous and distributed manufacturing systems is thus possible.

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