• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • Tagged with
  • 5
  • 5
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Indoor Human Information Acquisition from Physical Vibrations

Pan, Shijia 01 May 2018 (has links)
With the growth of networked smart devices in indoor environments, human information acquisition becomes essential for these devices to make the environment smart and people’s lives more convenient. These networked systems, which are often referred to as Cyber-Physical Systems (CPS), learn and make decisions collaboratively based on data input. The data could come from sensors that perceive various signals in the physical world, human input, etc. In this thesis, I will focus on information acquisition based on data from sensing the physical world. The major challenges to accurately interpreting the information these systems perceive result from the complexity of the physical world. An extreme solution to this problem is to have a large number of sensors or sensing configurations that collect a large amount of data. Ideally, we could then have labeled data for each sensing condition and possible scenario in order to accurately model the world. However, in the real world, such solutions could be difficult if not impossible to achieve due to constraints on the hardware, computational power, and (labeled) dataset. This thesis targets this problem and sets the goal of obtaining accurate indoor human information through limited system configurations and limited labeled data. A new concept of utilizing structures as sensors is presented as the foundation of the system. The intuition is that people induce ambient structures to vibrate all the time, and their activities and information can be inferred from this vibration. To achieve that with the aforementioned constraints, an understanding of the physical world (that has been studied for centuries in multiple disciplines) is used to assist the sensing and learning process for more accurate information acquisition from sensor data.
2

Data Assimilation for Agent-Based Simulation of Smart Environment

Wang, Minghao 18 December 2014 (has links)
Agent-based simulation of smart environment finds its application in studying people’s movement to help the design of a variety of applications such as energy utilization, HAVC control and egress strategy in emergency situation. Traditionally, agent-based simulation is not dynamic data driven, they run offline and do not assimilate real sensor data about the environment. As more and more buildings are equipped with various sensors, it is possible to utilize real time sensor data to inform the simulation. To incorporate the real sensor data into the simulation, we introduce the method of data assimilation. The goal of data assimilation is to provide inference about system state based on the incomplete, ambiguous and uncertain sensor data using a computer model. A typical data assimilation framework consists of a computer model, a series of sensors and a melding scheme. The purpose of this dissertation is to develop a data assimilation framework for agent-based simulation of smart environment. With the developed data assimilation framework, we demonstrate an application of building occupancy estimation which focuses on position estimation using the framework. We build an agent based model to simulate the occupants’ movement s in the building and use this model in the data assimilation framework. The melding scheme we use to incorporate sensor data into the built model is particle filter algorithm. It is a set of statistical method aiming at compute the posterior distribution of the underlying system using a set of samples. It has the benefit that it does not have any assumption about the target distribution and does not require the target system to be written in analytic form .To overcome the high dimensional state space problem as the number of agents increases, we develop a new resampling method named as the component set resampling and evaluate its effectiveness in data assimilation. We also developed a graph-based model for simulating building occupancy. The developed model will be used for carrying out building occupancy estimation with extremely large number of agents in the future.
3

Experiment Design for Closed-loop System Identification with Applications in Model Predictive Control and Occupancy Estimation

Ebadat, Afrooz January 2017 (has links)
The objective of this thesis is to develop algorithms for application-oriented input design. This procedure takes the model application into account when designing experiments for system identification. This thesis is divided into two parts. The first part considers the theory of application-oriented input design, with special attention to Model Predictive Control (MPC). We start by studying how to find a convex approximation of the set of models that result in acceptable control performance using analytical methods when controllers with no closed-form control law, for e.g., MPC are employed. The application-oriented input design is formulated in time domain to enable handling of signals constraints. The framework is extended to closed-loop systems where two cases are considered i.e., when the plant is controlled by a general but known controller and for the case of MPC. To this end, an external stationary signal is designed via graph theory. Different sources of uncertainty in application-oriented input design are investigated and a robust application-oriented input design framework is proposed. The second part of this thesis is devoted to the problem of estimating the number of occupants based on the information available to HVAC systems in buildings. The occupancy estimation is first formulated as a two-tier problem. In the first tier, the room dynamic is identified using temporary measurements of occupancy. In the second tier, the identified model is employed to formulate the problem as a fused-lasso problem. The proposed method is further developed to be used as a multi-room estimator using a physics-based model. However, since it is not always possible to collect measurements of occupancy, we proceed by proposing a blind identification algorithm which estimates the room dynamic and occupancy, simultaneously. Finally, the application-oriented input design framework is employed to collect data that is informative enough for occupancy estimation purposes. / <p>QC 20170620</p>
4

Ecology, Habitat Use, and Conservation of Asiatic Black Bears in the Min Mountains of Sichuan Province, China

Trent, Jewel Andrew 13 July 2010 (has links)
This project was initiated in an attempt to address the paucity of data on Asiatic black bears (Ursus thibetanus) in Mainland China. Field work was carried out from May 2004 – August 2006 within the Tangjiahe National Nature Reserve in northwestern Sichuan Province, China. Initial methodology relied on trapping and GPS radio-collaring bears, but due to extreme difficulty with capturing a sufficient sample size, I expanded the study to include reproduction, feeding analysis from scats and sign, and occupancy modeling from sign surveys. I documented the home ranges of an adult female (100% MCP = 107.5km2, n=470 locations) and a sub-adult female (100%MCP = 5.9km2, n=36 locations) Asiatic black bear. I also documented two birthing occasions with a total of four male cubs produced and eight bear den sites. I collected feeding data from 131 scat samples and 200 bear sign transects resulting in 50 identified food items consumed by Asiatic black bears. I also employed the program PRESENCE to analyze occupancy data using both a standard grid repeated sampling technique and an innovative technique of aging bear sign along strip transect surveys to represent repeated bear occupancy over time. Conservation protection patrolling and soft mast were shown to be the most important factors determining the occupancy of an area by Asiatic black bears in Tangjiahe Nature Reserve, Sichuan Province, China. / Master of Science
5

Privacy-preserving Building Occupancy Estimation via Low-Resolution Infrared Thermal Cameras

Zhu, Shuai January 2021 (has links)
Building occupancy estimation has become an important topic for sustainable buildings that has attracted more attention during the pandemics. Estimating building occupancy is a considerable problem in computer vision, while computer vision has achieved breakthroughs in recent years. But, machine learning algorithms for computer vision demand large datasets that may contain users’ private information to train reliable models. As privacy issues pose a severe challenge in the field of machine learning, this work aims to develop a privacypreserved machine learningbased method for people counting using a lowresolution thermal camera with 32 × 24 pixels. The method is applicable for counting people in different scenarios, concretely, counting people in spaces smaller than the field of view (FoV) of the camera, as well as large spaces over the FoV of the camera. In the first scenario, counting people in small spaces, we directly count people within the FoV of the camera by Multiple Object Detection (MOD) techniques. Our MOD method achieves up to 56.8% mean average precision (mAP). In the second scenario, we use Multiple Object Tracking (MOT) techniques to track people entering and exiting the space. We record the number of people who entered and exited, and then calculate the number of people based on the tracking results. The MOT method reaches 47.4% multiple object tracking accuracy (MOTA), 78.2% multiple object tracking precision (MOTP), and 59.6% identification F-Score (IDF1). Apart from the method, we create a novel thermal images dataset containing 1770 thermal images with proper annotation. / Uppskattning av hur många personer som vistas i en byggnad har blivit ett viktigt ämne för hållbara byggnader och har fått mer uppmärksamhet under pandemierna. Uppskattningen av byggnaders beläggning är ett stort problem inom datorseende, samtidigt som datorseende har fått ett genombrott under de senaste åren. Algoritmer för maskininlärning för datorseende kräver dock stora datamängder som kan innehålla användarnas privata information för att träna tillförlitliga modeller. Eftersom integritetsfrågor utgör en allvarlig utmaning inom maskininlärning syftar detta arbete till att utveckla en integritetsbevarande maskininlärningsbaserad metod för personräkning med hjälp av en värmekamera med låg upplösning med 32 x 24 pixlar. Metoden kan användas för att räkna människor i olika scenarier, dvs. att räkna människor i utrymmen som är mindre än kamerans FoV och i stora utrymmen som är större än kamerans FoV. I det första scenariot, att räkna människor i små utrymmen, räknar vi direkt människor inom kamerans FoV med MOD teknik. Vår MOD-metod uppnår upp till 56,8% av den totala procentuella fördelningen. I det andra scenariot använder vi MOT-teknik för att spåra personer som går in i och ut ur rummet. Vi registrerar antalet personer som går in och ut och beräknar sedan antalet personer utifrån spårningsresultaten. MOT-metoden ger 47,4% MOTA, 78,2% MOTP och 59,6% IDF1. Förutom metoden skapar vi ett nytt dataset för värmebilder som innehåller 1770 värmebilder med korrekt annotering.

Page generated in 0.1155 seconds