204 research outputs found
DandeBot - An Autonomous Weeding Solution for Residential Lawns
No full textDandeBot – An Autonomous Weeding Solution for Residential Lawns
Author: Nishanth Rajkumar
This thesis presents the development and validation of DandeBot, an autonomous robotic system designed for comprehensive residential lawn maintenance. The robot addresses the need for efficient, eco-conscious, and low maintenance lawn care through a fully electric platform powered by an AI-driven software stack. Emphasizing safety, adaptability, and ease of use, the hardware was developed using CAD and Design for Manufacturing (DFM) principles, resulting in a modular and robust design. The integrated software stack combines localization, mapping, and path planning using odometry, visual odometry, and IMU data fusion to navigate dynamic outdoor environments. Task-specific algorithms were developed and validated for autonomous navigation, weed detection, and obstacle avoidance. Key hardware innovations include a modular gripper system for weed removal and adaptable attachments for multiple lawn care tasks. Field trials confirmed the robot’s capability to perform with high precision and reliability in varied lawn conditions, significantly reducing the need for human intervention. This work contributes to the growing field of service robotics by demonstrating how intelligent systems can automate routine household maintenance. The thesis concludes by outlining future research directions, including system scalability, enhanced multi-tasking capabilities, and integration with smart home networks
Exploring Stability and Accuracy Limits of Distributed Real-Time Power System Simulations via System-of-Systems Cosimulation
No full textElectro-Magnetic Transients (EMT) is the most accurate, but computationally expensive method of analyzing power system phenomena. Thereby, interconnecting several real-time simulators can unlock scalability and system coverage, but leads to a number of new challenges, mainly in time synchronization, numerical stability, and accuracy quantification. This study presents such a co-simulation, based on Digital Real-Time Simulator (DRTS), connected via Aurora 8B/10B protocol. Such a setup allows to analyze complex and hybrid System-of-Systems (SoS) whose resulting numerical phenomena and artifacts have been poorly investigated and understood so far. We experimentally investigate the impact of IEEE 1588 Precision Time Protocol (PTP) synchronization assessing both time and frequency domains. The analysis of the experimental results is encouraging and show that numerical stability can be maintained even with complex system setups. Growing shares of inverter-based renewable power generation require larger and interconnected EMT system studies. This work helps to understand the phenomena connected to such DRTS advanced co-simulation setups
Semantic Question Classification Datasets
No full textThis is the datasets used in the following paper:Can Taxonomy Help? Improving Semantic Question Matching using Question TaxonomyPaper: http://aclweb.org/anthology/C18-1042If you use the dataset please cite the following paper:@InProceedings{C18-1042,
author = "Gupta, Deepak
and Pujari, Rajkumar
and Ekbal, Asif
and Bhattacharyya, Pushpak
and Maitra, Anutosh
and Jain, Tom
and Sengupta, Shubhashis",
title = "Can Taxonomy Help? Improving Semantic Question Matching using Question Taxonomy",
booktitle = "Proceedings of the 27th International Conference on Computational Linguistics",
year = "2018",
publisher = "Association for Computational Linguistics",
pages = "499--513",
location = "Santa Fe, New Mexico, USA",
url = "http://aclweb.org/anthology/C18-1042"
}
</div
Stability and Accuracy Analysis of a Real-time Co-simulation Infrastructure
No full textCo-simulation techniques are gaining popularity amongst the power system research community to analyse future scalable Smart Grid solutions. However, complications such as multiple communication protocols, uncertainty in latencies are holding-up the widespread usage of these techniques for power system analysis. These issues are even further exacerbated when applied to Digital Real-Time Simulations (DRTS) with strict real-time constraints for Power Hardware-In-the-Loop (PHIL) tests. In this paper, we thoroughly test and demonstrate an innovative co-simulation infrastructure that allows to interconnect different DRTS through the Aurora 8B/10B protocol to reduce the effects of communication latency and respect real-time constraints. The Ideal Transformer Method Interface Algorithm (ITM IA), commonly used in PHIL applications, is used to interface the DRTS. Finally, we present time-domain and frequency-domain accuracy analyses on the obtained experimental results to demonstrate the potential of the proposed infrastructure.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Intelligent Electrical Power Grid
Improvement of cost estimating internal practice.
No full textThis thesis is concerned with understanding the internal costing practices employed
by commercial and engineering disciplines of cost estimating for generating
estimates at the conceptual design stage of complex hardware products. It examines
whether there is a formal structure in the interaction between the two groups that
can be represented within a model. The aim is to develop a framework that will
formalise and improve the communication of commercial and engineering
disciplines in cost estimating.
A literature review examines the role of different costing techniques and the
information requirements for generating cost estimates. The review identifies that
there is a lack of research in the information requirements for cost estimating of
specific manufacturing industries, and that the interaction of commercial and
engineering disciplines of cost estimating at conceptual design stage is hindered by
the different focuses of these groups.
By conducting a survey study the author identifies the internal practice in
cost estimating for the automotive industry. The survey establishesth at in order to
improve the internal practice it is essential to establish a data infrastructure that
fortnalises and enables the reuse of the cost estimates and improves the interaction
between the two groups. The author identifies a common cost estimating process
for the automotive industry. This study establishes the required data and
information elements and information sources that need to be collected in order to
have reliable data infrastructure. Using a case study approach, the author also
establishes that it is essential to analyse the product functions in such a way that
will enable the development of a detailed cost estimating model at the conceptual
design stage, which will improve interaction between the commercial and
engineering groups. The function-based cost estimating process becomes the focus
of detailed studies using experts from the automotive industry. This results in a
generic framework that provides a formalised structure to represent functional
requirements in the form of a detailed cost estimating model.
The thesis concludes that product functions need to be captured and
analysedd uring the conceptuald evelopmento f a product and be associatedto cost
estimates. The developed results provide both groups of cost estimating a
structured, consistent approach to developing cost estimates at the conceptual
design stage. The data infrastructure and the function-based cost estimating
framework is validated through case studies and expert evaluation. The approach
contributes towards improvement of the internal cost estimating practice with the
automotive industry
Development of an impact assessment framework for lean manufacturing within SMEs
No full textThe main aim of the research work presented in this thesis, is the development of a
novel framework with the capability of assessing the impact of implementing lean
manufacturing within small-to-medium sized manufacturing firms (SMEs). By assessing
the impact of lean implementation, SMEs can make informed decisions on the viability
of lean adoption at the conceptual implementation stage. Companies are also able
determine their status in terms of lean manufacturing affordability.
Thus, in order to achieve the above-stated aim, the following were the main set research
objectives; (1) identifying the key drivers for implementing lean manufacturing within
SMEs, (2) investigating the operational activities of SMEs in order to understand their
manufacturing issues, (3) exploring the current level of lean manufacturing usage within
SMEs so as to categorise users based on their levels of involvement, (4) identifying
factors that determine the assessment of lean manufacturing, (5) developing an impact
assessment framework for justifying lean manufacturing within SMEs, (6) developing a
knowledge based advisory system and (7) validating the impact assessment framework
and the developed knowledge based advisory system through real-life case studies,
workshops, and expert opinions.
A combination of research methodology approaches have been employed in this
research study. This comprises literature review, observation of companies' practices
and personal interview. The data collection process involved ten SMEs that provided
consistent information throughout the research project life. Additionally, visitations to
three large size manufacturing firms were also conducted. Hence, the framework and
system development process passed through several stages. Firstly, the data were
collected from companies who had successfully implemented lean manufacturing within
their premise. The second development stage included the analysis and validation of the
dataset through company practitioners. An impact assessment framework was thus developed with the aid of regression analysis as a predictive model. However, it was
realised that there were few correlations between the dataset generated and analysis. The
reasons for this were unclear.
,a
knowledge based advisory system was adopted to
conceptualise, enhance the robustness of the impact assessment framework and address
the problem of the imprecise data in the impact assessment process.
Three major factors of impact assessment were considered in the framework and the
system development process, namely relative cost of lean implementation, a company
lean readiness status and the level of value-added to be achieved (impact/benefits).
Three knowledge based advisory sub-systems that consisted of the abovementioned
factors were built. Results obtained from them were then fed into the final system. The
three sub-systems were validated with the original set of data from companies. This
enabled the assignment of a number of input variables whose membership functions
aided the definition of the fuzzy expert system language (linguistic variables) used. The
final system yielded heuristic rules that enable the postulation of scenarios of lean
implementation. Results were sought and tested on a number of firms based within the
UK, for the purposes validation. These also included expert opinions both in academic
and industrial settings.
A major contribution of the developed system is its ability to aid decision-making
processes for lean implementation at the early implementation stage. The visualisation
facility of the developed system is also useful in enabling potential lean users to make
forecasts on the relative cost of lean projects upfront, anticipate lean benefits, and realise
one' degree of lean readiness
The implications of foreign aid fungibility for development assistance
No full textA foreign aid or foreign lending policy that focuses exclusively on project financing may have unintended consequences, report the authors. New research shows that aid intended for crucial social and economic sectors often merely substitutes for spending that recipient governments would have undertaken anyway and the funds that are thereby freed up are spent for other purposes. If the aid funds something that would have been done anyway, traditional ways of evaluating the aid's effectiveness are not really accurate. Ifaid funds are fungible and the recipient's public spending program is unsatisfactory, project lending may not be cost-effective. If the recipient's public spending program is satisfactory, perhaps the donor should finance a portion of it instead of financing individual projects. One solution to the problem of fungibility, then, is that donors could tie assistance to an overall public spending program (in the recipient country) that provides adequate resources to crucial sectors. To make this kind of reform operational, the authors propose a new lending instrument: a public expenditure reform loan (PERL). A PERL would tie an institution's lending strategy to the recipient country's achievement of mutually agreed-upon development goals. Everyone agrees that better donor coordination is needed, but it has been difficult to achieve because some donors tend to prefer projects (usually with the national flag flying over them). By agreeing on a public expenditure program and financing a portion of it, the World Bank credibly ask other donors to do the same.Payment Systems&Infrastructure,Development Economics&Aid Effectiveness,Gender and Development,Decentralization,Economic Adjustment and Lending,Development Economics&Aid Effectiveness,Poverty Assessment,National Governance,Economic Adjustment and Lending,Public Sector Economics&Finance
Stability and Accuracy Analysis of a Distributed Digital Real-Time Co-simulation Infrastructure
No full textCo-simulation techniques are gaining popularity amongst the power system research community to analyse future scalable Smart Grid solutions. However, complications such as multiple communication protocols, uncertainty in latencies are holding up the widespread usage of these techniques for power system analysis. These issues are even further exacerbated when applied to Digital Real-Time Simulators (DRTS) with strict real-time constraints for Power Hardware-In-the-Loop (PHIL) tests.In this paper, we present an innovative Digital Real-Time Co-simulation Infrastructure that allows interconnecting differentDRTS through the Aurora 8B/10B protocol to reduce the effects of communication latency and respect real-time constraints. The proposed solution synchronizes the DRTS interconnection by means of the IEEE 1588 Precision Time Protocol (PTP) standard to align executions and results obtained by the co-simulated scenario. The Ideal Transformer Method (ITM) Interface Algorithm(IA), commonly used in PHIL applications, is used to interface theDRTS. Finally, we present time-domain and frequency-domain accuracy analyses on the obtained experimental results to demonstrate the potential of the proposed infrastructure. With the presented setup, a time step duration down to50μsis shown to be stable and accurate in running an Electro-Magnetic Transients(EMT) co-simulated power grid scenario by interconnecting two commercial DRTS (i.e. RTDS NovaCor), extending the scalability of future Smart Grid real-time simulations
Role of aging time on the magnetic properties of Sm2Co17 permanent magnets processed through cold isostatic pressing
No full textUnderstanding Sentiment Words and Truthful Opinions from Academic Feedbacks
No full textOnline feedbacks have become increasingly popular means of gathering students’ reviews and judging the quality of various services offered by an institution, such as courses, teaching, evaluation, infrastructure and many others. Generally, academic feedbacks include values through numerical ratings and free text comments. In this paper, we employ a natural language-based approach to extract features of feedbacks, capture sentiment words from those feedbacks and build opinion vocabulary from the corpus of academic feedbacks. Also, we focus on studying student behaviour while reporting their feedbacks. Particularly, we investigate the reliability of quantitative features through numerical ratings that students offer, by estimating the linguistic evidence from the free text in the feedback
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