Miracle-dz/UniFAR-FTUs huggingface dataset:
A Vision-Based Relative Navigation Approach for Autonomous Multirotor Aircraft

A Vision-Based Relative Navigation Approach for Autonomous Multirotor Aircraft Robert C. Leishman Department of Mechanical Engineering, BYU Doctor of Philosophy Autonomous flight in unstructured, confined, and unknown GPS-denied environments is a challenging problem. Solutions could be tremendously beneficial for scenarios that require information about areas that are difficult to access and that present a great amount of risk. The goal of this research is to develop a new framework that enables improved solutions to this problem and to validate the approach with experiments using a hardware prototype. In Chapter 2 we examine the consequences and practical aspects of using an improved dynamic model for multirotor state estimation, using only IMU measurements. The improved model correctly explains the measurements available from the accelerometers on a multirotor. We provide hardware results demonstrating the improved attitude, velocity and even position estimates that can be achieved through the use of this model. We propose a new architecture to simplify some of the challenges that constrain GPSdenied aerial flight in Chapter 3. At the core, the approach combines visual graph-SLAM with a multiplicative extended Kalman filter (MEKF). More importantly, we depart from the common practice of estimating global states and instead keep the position and yaw states of the MEKF relative to the current node in the map. This relative navigation approach provides a tremendous benefit compared to maintaining estimates with respect to a single global coordinate frame. We discuss the architecture of this new system and provide important details for each component. We verify the approach with goal-directed autonomous flight-test results. The MEKF is the basis of the new relative navigation approach and is detailed in Chapter 4. We derive the relative filter and show how the states must be augmented and marginalized each time a new node is declared. The relative estimation approach is verified using hardware flight test results accompanied by comparisons to motion capture truth. Additionally, flight results with estimates in the control loop are provided. We believe that the relative, vision-based framework described in this work is an important step in furthering the capabilities of indoor aerial navigation in confined, unknown environments. Current approaches incur challenging problems by requiring globally referenced states. Utilizing a relative approach allows more flexibility as the critical, real-time processes of localization and control do not depend on computationally-demanding optimization and loop-closure processes.
Crosstalk reduction in copper on‐chip interconnects with graphene barrier for ternary logic applications

This paper presents the investigations of crosstalk effects in ternary logic‐based coupled interconnects. The crosstalk analysis is investigated for coupled copper interconnects and copper‐multilayer graphene (Cu‐MLG) interconnects. In Cu‐MLG interconnects, the Cu interconnect is enclosed with MLG barrier and standard ternary inverter is used to drive the interconnect. Based on the industry standard HSPICE simulation results, the crosstalk effects such as noise peak and delay are lower compared with conventional Cu interconnects. Moreover, the Cu‐MLG interconnects show reduced power dissipation, power delay product (PDP), and energy delay product (EDP) over the Cu interconnects. From the simulation results, it is observed that the Cu‐MLG interconnects provides the performance improvements up to 30.67% compared with the Cu interconnects. Thus, the Cu‐MLG interconnects are more compatible for ternary logic integrated circuits compared with traditional Cu interconnects.
Synthesis and Characterization of Porous Magnetite Nanosphere Iron Oxide as a Novel Adsorbent of Anionic Dyes Removal from Aqueous Solution

Porous magnetite Fe3O4 nanospheres (PMNs) are synthesized for removal from an aqueous solution of anionic dyes Acid Red 57 (AR57) and Remazol Red (RR) and are used as a high-performance adsorbent. Characterization of PMNs was carried out using various techniques, such as Fourier-transform infrared spectroscopy, the surface area measured by Brunauer Emmett-Teller (BET), and it was found 143.65m2g-1, and were spherical-shaped as determined by TEM. Surface modification was calculated using electron microscopy (SEM) scanning. The spherical morphology of the PMNs is very uniform, with an average particle size of ~25,84 nm in diameter. Variables such as initial pH, the dosage of adsorbent, contact time, and temperature were analyzed to find the optimal adsorption conditions for extracting Acid Red 57 (AR57) and Remazol Red (RR) from aqueous solutions. For respective AR57 and RR, the optimal pH for the extraction of the anionic dyes examined from water solutions was 3 and 4. The maximum adsorption potential expected for AR57 and RR dyes was 888.68 and 808.43 mgg−1, respectively. The effects of the initial solution pH, temperature, initial concentration, contact time, salinity, and dosing of PMNs were systematically analyzed. These dyes were suitable for acid pH adsorption, as the PMNs Zero-charge point (pHPZC) equals 4.3. Adsorption findings were based on the Langmuir, Freundlich, Dubinin – Radushkevich, and Temkin adsorption isotherms. The adsorption isotherm had been found to follow the Langmuir model for both dyes. The mean adsorption energy (Ea) is 20.24 and 31.3 kJmol−1 for AR57 and RR, respectively, indicating a chemisorption process. The adsorption kinetics had been found to follow the pseudo-second-order kinetic model. The adsorption process was verified to be endothermic and spontaneous by thermodynamic studies. Using ethanol as a solvent, it was also studied the process of desorption of the adsorbed anionic dyes.
Analysis of Breakdown Characteristics by Lane Interaction at Freeway Merging Area with a View of Time and Space

The purpose of this paper is to perform a basic study on the interaction between lanes, which can be achieved through analyzing traffic breakdown at the microscopic level. Using aerial photographic data for the microscopic analysis, this study analyzed the characteristics of traffic flow at a merging area. This research produced aggregated traffic data such as flows, speeds, and densities in 30 second intervals by lane for the macroscopic analysis and individual headway data by lane for the microscopic analysis. The paper contains an analysis of lane characteristics through flows, speeds, densities, and headway variations and also investigates the influence of ramp flows on mainline flows with space-time diagrams. Firstly, the merging area in this study is divided into three sections: before-merging, during-merging, and after-merging. The transition process was analyzed at each lane. Secondly, the breakdown was observed in detail with data divided in 50-foot units. The breakdown was checked through the relationships between ramp and freeway mainline flows, various techniques were proposed to analyze the breakdown, and the formation of breakdown was introduced as three stages in this study. In the near future, the findings of this study could contribute to determining the dynamic capacity on freeways by easily understanding changeable traffic breakdown patterns over time and space.
Visualization's Next Frontier

Increasingly, engineers can synthesize two-dimensional data into various types of three-dimensional (3-D) and dynamic (animated or real-time simulation) four-dimensional models, renderings, animations, and simulations. Advances in personal computing and development of computer-aided design and drafting have helped put a new approach--design visualization--directly into the hands of highway designers. For years, transportation practitioners have used 3-D computerized renderings and animation to convey conceptual designs to decision makers, stakeholders, and communities during the public involvement phase of transportation projects. But now agencies are pushing design visualization to the next level, taking it beyond public involvement and integrating it into the entire project development process, from early conceptualization to final design and even actual construction. This article provides an overview of design visualization. Available technologies are highlighted, as well as benefits and challenges associated with applying design visualization. Early adopters of the 3-D modeling and visualization approach are leading the design and construction industry by demonstrating cost savings and enhanced quality. Taking visualization to the next level will require the transportation industry to establish national standards with guidelines for its application, design analysis, budgeting, training, and staffing. Additional research should quantify visualization's cost and benefits and should determine how it helps the designer and, ultimately, end users.
Development of dry barriers for containment and remediation at waste sites

This paper describes a concept in which dry air is injected into an unsaturated formation to reduce the soil moisture content, referred to here as a dry (or sometimes tensiometric) barrier. The objective is to reduce the hydraulic conductivity of the unsaturated media to the point where liquid phase transport becomes negligible, thereby achieving containment. The concept could be applied in subsurface formations to provide containment from a leaking facility, or it could be incorporated into a cover design to provide redundancy for a capillary barrier. The air injection process could in principle be coupled with a vacuum extraction system to recover soil vapors, which would then provide a remediation process that would be appropriate if volatile organic compounds were present. Work to date has consisted of a combined theoretical, laboratory, and field research investigation. The objective of this research was to demonstrate the technical feasibility of the dry barrier concept by identifying the parameters which determine its effectiveness. Based on the results obtained for the experimental and theoretical studies, feasibility analyses were prepared for as a modification for a landfill cover design to prevent infiltration from atmospheric precipitation and for potential application of dry barriers to achieve subsurface containmentmore » and removal of volatile constituents. These analyses considered the technical as well as the economic aspects of the dry barrier concept. « less
Different Inter-Organizational Collaboration Approaches in Coworking Spaces in Barcelona

Inter-organizational collaboration plays a crucial role in the innovative capacity and competitiveness of firms. This article discusses the collaboration practices in localized spaces of collaboration through a study of different coworking spaces in Barcelona, following an inductive and qualitative approach. Three types of collaboration approaches are identified: 1) cost-related collaboration, where agents are motivated in reducing their operational costs and the transaction costs related to collaboration; 2) resource-based collaboration, where agents collaborate to learn or complement their resources by integrating external resources and sources of knowledge; and 3) relational collaboration, where actors engage in intense synergistic collaborative practices. The results show that each coworking space tends to focus on one kind of collaboration type that is influenced in different ways by the coworking space managers. The article contributes to the research on inter-organizational collaboration by explaining how the physical environment and the action of the space and community managers can facilitate the implementation of different collaborative practices among colocated economic agents.
Social Networking Services: A Case Study in the Failure to Facilitate Knowledge Sharing in Organizations : A Case Study of Enterprise 2.0 Taolin Platform

Social networking services are relatively new phenomena and they have attracted so much attention around themselves. These services have been seen by many organizations as a po-tential tool to facilitate knowledge sharing. However, very few have successfully adopted such services. Many problems which lead to failures arise when it comes to developing and implementing social networking services with the goal to facilitate knowledge sharing.The purpose of this thesis is to investigate the failure of one social networking service to satisfy the knowledge sharing needs of the organization that has developed and implement-ed it in-house.Interviews with three employees of the company were arranged. The interviews were done with time intervals in between. This gave us the opportunity to rearrange the questions that were going to be asked to the next interviewee. The interviews were really helpful and gave us a good insight of the problem with the development and implementation of the social networking service that the organization was facing. After the interviews were conducted, a questionnaire was elaborated and sent out to the employees in the organization.The results we came up with were really interesting. A table with failure factors for the so-cial networking service used in the organization was made and a model suggesting the steps an organization should follow for the successful development and implementation of a so-cial networking service that facilitates knowledge sharing internally was developed.We found out that the failure was not in the social networking service itself but in the way it was presented, positioned and communicated to the employees of the company. They never took the service seriously for its intended purpose which was knowledge sharing within the organization and that led to the cancelation of the project.
Toward an Automated System for the Analysis of Cell Behavior: Cellular Event Detection and Cell Tracking in Time-lapse Live Cell Microscopy

Time-lapse live cell imaging has been increasingly employed by biological and biomedical researchers to understand the underlying mechanisms in cell physiology and development by investigating behavior of cells. This trend has led to a huge amount of image data, the analysis of which becomes a bottleneck in related research. Consequently, how to efficiently analyze the data is emerging as one of the major challenges in the fields. Computer vision analysis of non-fluorescent microscopy images, representatively phase-contrast microscopy images, promises to realize a long-term monitoring of live cell behavior with minimal perturbation and human intervention. To take a step forward to such a system, this thesis proposes computer vision algorithms that monitor cell growth, migration, and differentiation by detecting three cellular events—mitosis (cell division), apoptosis (programmed cell death), and differentiation—and tracking individual cells. Among the cellular events, to the best our knowledge, apoptosis and a certain type of differentiation, namely muscle myotubes, have never been detected without fluorescent labeling. We address these challenging problems by developing computer vision algorithms adopting phase contrast microscopy. We also significantly improve the accuracy of mitosis detection and cell tracking in phase contrast microscopy over previous methods, particularly under non-trivial conditions, such as high cell density or confluence. We demonstrate the usefulness of our methods in biological research by analyzing cell behavior in scratch wound healing assays. The automated system that we are pursuing would lead to a new paradigm of biological research by enabling quantitative and individualized assessment in behavior of a large population of intact cells.
Development of quantitative methodology for assessing embodied energy of recyclable and reusable materials/products

A quantitative method of life cycle assessment (LCA) has been developed to enable an energy audit of the process of material recycling to be carried out. An equation has been derived to provide information on the optimum balance between adverse environmental effects and beneficial recycling/reuse capabilities. The parameter analysed is the embodied energy of a material or product, but the LCA could equally be applied to other environmental burdens, such as CO 2 , SO x , and NO x emissions. IS/1202
Automated building monitoring using a wireless sensor network

Building monitoring is one of the challenging issues in building construction, due to its high cost and the time consuming procedure for implementation and maintenance. It is also a critical issue that directly affects building security, safety, and management, energy saving, and tenants' convenience. Wireless sensor networking is a new networking technology that holds great promise for monitoring, evaluation and management of buildings. However, sufficient work has not been done in the application part of wireless sensor networks for building monitoring. In this thesis, we show how advanced wireless sensor technology can be used by building managers to monitor climate conditions, brightness level, lamp status and room occupancy in buildings as well as by the wireless sensor network administrator to monitor the nodes' connectivity and conditions in the network. We conceive of the building monitoring application as being divided into three main parts. First, wireless sensor hardware is programmed to process signals from sensors and transmit the data in a suitable format to a gateway/server application using multi-hop routing. The second task involves the forwarding of the signals sent by the wireless sensor nodes to the end user application by the gateway/server further retrieval and analysis. The third part consists of an end user application for processing the sensor data sent by the wireless sensor nodes and then forwarded by the gateway/server. The end user application visualizes the network topology, network connectivity graph and real time information of individual motes. In addition, this application provides the real time analysis of the data and functionalities for search and observation. Finally, the end user application allows users to analyze the rooms and network conditions by mining the database using different parameters such as the type of data and the time of data acquisition. The system and related analysis were applied on a real case study -- the eighth and ninth floors of the Engineering and Visual Arts building of Concordia University.
Advanced experimental procedure for in-duct aero-acoustics

The purpose of this paper is to present a method for characterization of in-duct aero-acoustic sources that can be described as active acoustic two-ports. The method is applied to investigate the sound produced from an orifice plate. The motivation is to obtain better data for the development of improved prediction methods for noise from flow singularities, e.g., in HVAC systems on aircrafts. Most of the earlier works fall into two categories; papers modeling the scattering of acoustic waves and papers modeling the sound generation. Concerning the scattering it is possible to obtain estimates of the low frequency behavior from linear perturbations of the steady state equations for the flow. Concerning the sound generation most of the presented work is experimental and follows a paper by Nelson&Morfey, which present a scaling law procedure for the in-duct sound power based on a dipole model of the source. One limitation with the earlier works is that the sound power only was measured on the downstream side. Also data was only obtained in 1/3-octave bands, by measuring the sound radiated from an open duct termination. Assuming plane waves and linear acoustics the flow duct singularity can be completely modeled as an active 2-port. The experimental determination of its properties is done in a two steps procedure. In the first step the passive data, i.e., the scattering matrix S, is determined using external (independent) sources. In the second step the S matrix is used and the source vector is determined by testing the system with known acoustic terminations.
A framework for the requirements engineering process development

As one of the processes in software engineering, requirements engineering (RE) plays a vital role in ensuring the overall success of the software engineering process. However, many of the substantial problems that the software industry faces today are still the same as the ones discovered during the software engineering crisis 36 years ago. Poor RE practices have been blamed as one of the major reasons contributing to the vicious circle. RE is a discipline emphasizing the implementation of engineering disciplines into the RE process by using various good practices, techniques and methodologies. A sound RE process is the foundation for the overall quality of any software product. Even though numerous process models, good practices, and techniques have been developed which aim at providing necessary support for RE processes, a huge gap still exists between the theory and practices. One of the major reasons contributing to this phenomenon is that there is a lack of suitable tools and/or guidance to support developing the most suitable RE process model and selecting the most suitable RE techniques for a software project. The effective ways have to be found to help fill in the gap. The objectives of this research were, therefore, to investigate a theoretically sound and practically feasible framework which can provide constructive and productive solutions to the problems identified by combining the theories and technologies of advanced software engineering, requirements engineering, knowledge engineering, and decision support. The outcome of this is the A Fbramework for Rbequirements Ebngineering pRbocess dEbvelopment (FRERE), which consists of a requirements engineering knowledge base, methodologies for RE process development and RE techniques selection, RE process assessment models, and a prototype of the FRERE tool. The framework provides constructive methodologies, with the help of the requirements engineering knowledge base and process assessment models, to develop the most suitable RE process model and suitable RE techniques for the given software project. The FRERE tool is a knowledge-based decision support system which can advise the requirements engineers during the development of RE process. The case study conducted during the research has shown the feasibility of the framework.