491 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
The effect of a smoking ban on exposure and cardio-respiratory health of non-smoking hospitality workers in Switzerland
No full textSummary: Background
The first scientific studies on negative health effects of passive smoking published in
the 1980s instigated an intense battle between the tobacco industry, who fear the
loss of social acceptance of smoking and resultant financial damages, and diverse
interest groups defending the health of the non-smoking population. In 2003 the
World Health Organisation issued a Framework Convention for Tobacco Control,
which was signed by 168 member states and has been ratified by 176.
Since then, several countries have implemented smoking bans in public indoor
spaces and workplaces. At the same time studies on second hand smoke (SHS)
exposure and related health effects in hospitality workers have been conducted
using various, albeit unreliable, methods. For example, exposure is typically
assessed by means of a questionnaire or by measuring a proxy such as PM2.5.
Likewise, measuring nicotine in biological samples such as urine, blood or saliva
may be influenced by personal metabolism. Most health-related studies focus on
respiratory examinations and have completely neglected long-term effects of SHS
exposure on cardiovascular health. This study aims to address some of these
knowledge gaps.
In May 2010 Switzerland implemented the first national smoking ban to protect the
population from passive smoking. Loose regulation left room for exceptions; there
remained a possibility to establish small smoking venues or separate smoking
rooms of limited size. The COSIBAR study utilized the transition as a natural
intervention to examine exposure and the cardio-respiratory health of non-smoking
hospitality workers.
Methods
An intervention group that experienced a change in smoking regulation was to be
compared with a control group that continued to work in a smoke-exposed
environment. To this end, the air was measured in 193 hospitality venues before the
ban in the cantons of Basel City, Basel County and Zurich. 92 workers were recruited
and invited to three medical examinations, once before implementation of the ban
and twice afterwards. Exposure was also measured each time, and at the first and
second time points a questionnaire on behaviour and acceptance was mailed to
participants. In this non-medical target group also smokers were included.
Exposure was measured by means of a passive nicotine-specific sampler. One was
placed at the workplace for a week and a second one was worn by the participants
for a personal 24-hour measurement. In addition, we took a salivary sample during
the medical examination to determine nicotine and cotinine content. A
questionnaire contained further questions on personal exposure.
Height, weight and blood pressure were measured in the medical component. We
did an ECG to assess heart rate variability (HRV)- a quantitative marker of
autonomic activity of the nervous system. We also measured pulse wave velocity
(PWV) to determine arterial stiffness which is an indicator of cardiovascular risk
factors and atherosclerosis. Respiratory health was examined by measuring lung
function and fractional exhaled nitric oxide (FeNO), an inflammatory marker in the
lungs. Furthermore we did an allergy test at baseline and performed an extensive
interview at each appointment.
To analyse the health data we developed several models; exposure was compared to
all health parameters in a cross-sectional baseline analysis. A longitudinal model
correlated exposure at every time point with corresponding health data taking into
account within-subject correlation. Finally, a pre/post comparison of health
parameters was done without taking exact exposure into account. All models were
adjusted for appropriate covariates.
The behaviour and acceptance questionnaire contained questions on personal
knowledge and attitude towards the smoking ban and factors influencing these as
well as on smoking status and behaviour. Responses were analysed with suitable
statistical tests.
Results
Average SHS exposure in the intervention group decreased by 2.4 cigarette
equivalents/day (CE/d) after the smoking ban while the change in the exposed
control group was significantly smaller.
In the cross-sectional analysis of the baseline data we found that mean lung function
of all exposed hospitality workers was below the recorded average for the Swiss
population. FeNO values were directly associated with exposure, meaning we
observed decreased inflammation with increased exposure.
In the longitudinal model that compared exposure to health measures, several HRV
parameters significantly correlated with exposure. A decrease by one unit CE/d was
linked to an increase in the root mean square of successive differences (RMSSD), the
standard deviation of N-N intervals (SDNN), high frequency (HF) and Total Power
(TP) as well as a decrease in PWV. These associations were consistent with the
original hypothesis that predicted better health with lower exposure.
In the pre/post model not taking exact exposure into account, there was a
significantly different development of several parameters in the intervention group
compared to the control group. SDNN, RMSSD, HF and TP increased in the
intervention group while decreasing in the control group. The inverse was true for
the low frequency/HF ratio (LF/HF), an effect that also corresponded to our
expectations. FeNO decreased in the intervention group, while the control group
showed a significantly different slight increase. No changes could be observed in
lung function.
Acceptance of the smoking ban was higher in non-smokers than in smokers
throughout the study. It rose from baseline to follow-up in both groups in the canton
of Basel Land which had a comprehensive smoking ban in place but not in the two
other cantons that had a regulation allowing exceptions.
Discussion
In this study there were clear indications for an improvement of cardiovascular
health in non-smoking hospitality workers after implementation of a smoking ban.
Summary
xiv
Risk factors for myocardial infarction or arteriosclerosis had significantly decreased
in the intervention group. No change in lung function was observed while FeNO
showed a decrease that cannot be considered clinically relevant. Hence, heart rate
variability and pulse wave velocity seem to be the most sensitive markers, while
lung function may take longer to recover or may remain irreversibly damaged. FeNO
is influenced by many factors and is in need of further research.
All these results speak for a comprehensive smoking ban without exceptions. The
higher acceptance that we observed with this type of regulation further supports
this recommendation.
Nevertheless an initiative by the lung association demanding exactly this
consolidation of the law was rejected in September 2012. During the animated
voting campaign, first study results were published. The failure of the campaign
raises the question if health is an attractive political argument when personal
freedom of decision is threatened. What more, the tobacco industry holds a
powerful position as an important employer and tax payer in Switzerland and its
role must be considered and moved into the people’s conscience. The alleged
personal freedom of Swiss citizens to decide on their smoking behaviour seems to
be an illusion, caused by concealed brainwashing by the world’s most manipulative
industry. ---------- Zusammenfassung: Hintergrund
Seit in den 1980er Jahren erste wissenschaftliche Studien die negativen
gesundheitlichen Folgen von Passivrauchen nachgewiesen haben, herrscht ein
unerbittlicher Kampf zwischen der Tabaklobby, die den Verlust der sozialen
Akzeptanz des Rauchens und damit verbundene finanzielle Einbussen fürchtet, und
verschiedenen Interessengruppen, die sich für die Gesundheit der nichtrauchenden
Bevölkerung einsetzen. Die Weltgesundheitsorganisation erliess 2003 ein
Rahmenübereinkommen zur Eindämmung des Tabakkonsums, das von 168 Staaten
unterschrieben und inzwischen von 176 ratifiziert wurde. Seither wurden in
mehreren Ländern Rauchverbote in öffentlichen Räumen und an Arbeitsplätzen
eingeführt. Dabei wurden oft Studien zu Rauchexposition und Gesundheitsfaktoren
von Gastgewerbemitarbeitern durchgeführt, mit unterschiedlichen Methoden. Die
Exposition wurde meistens anhand von Fragebogen oder unter Anwendung eines
Proxys wie PM2.5 eingeschätzt, was jedoch ungenau sein kann. Die Nikotinmessung
von biologischen Proben wie Urin, Blut oder Speichel kann ausserdem vom
persönlichen Metabolismus beeinflusst werden. Bezüglich der Gesundheit
konzentrierten sich die meisten Studien auf respiratorische Untersuchungen und
vernachlässigten kardiovaskuläre Langzeitauswirkungen der Passivrauchexposition
völlig. Mit dieser Studie sollten einige dieser Lücken gefüllt werden.
Im Mai 2010 wurde in der Schweiz das erste Bundesgesetz zum Schutz der
Bevölkerung vor Passivrauchen eingeführt. Da die lose Regelung Raum für
Ausnahmen liess, war es weiterhin möglich, kleine Raucherlokale oder abgetrennte
Rauchräume von begrenzter Grösse, zu führen. Die COSIBAR Studie nutzte die
Umsetzung als natürliche Intervention für eine Untersuchung der Exposition und
kardio?respiratorischen Gesundheit bei nichtrauchenden Gastgewerbemitarbeitern.
Methoden
Eine Interventionsgruppe, die eine Änderung der Rauchregel erfuhr, sollte mit einer
Kontrollgruppe verglichen werden, die weiterhin im Rauch arbeiten musste.
Dazu wurde vor dem Rauchverbot die Luft in 193 Betrieben in den Kantonen Basel
Stadt, Basel Land und Zürich gemessen. 92 Mitarbeiter konnten rekrutiert werden
und wurden zu drei medizinischen Untersuchungen eingeladen, einmal vor
Einführung des Rauchgesetzes und zweimal danach. Parallel wurde jeweils die
Exposition gemessen, sowie beim ersten und zweiten Erhebungszeitpunkt ein
Verhaltens?und Akzeptanzfragebogen verschickt, in dessen Zielgruppe auch
Raucher eingeschlossen wurden.
Die Exposition wurde mit Hilfe eines passiven Nikotinbadges gemessen, einerseits
während einer Woche am Arbeitsplatz und andererseits mit einer persönlichen
Messung, bei der der Proband den Badge 24 Stunden auf sich trug. Darüber hinaus
wurde während der medizinischen Untersuchung eine Speichelprobe genommen,
um den Nikotin? und Kotiningehalt festzustellen. Ein Fragebogen enthielt
zusätzliche Fragen zur Exposition.
Im medizinischen Teil wurde neben Grösse, Gewicht und Blutdruck ein EKG zur
Untersuchung der Herzrhythmusvariabilität (HRV), einem quantitativen Marker des
autonomen Nervensystems, durchgeführt. Anhand der Pulswellengeschwindigkeit
(PWV) wurde die arterielle Steifheit gemessen, die ein Indikator für kardiovaskuläre
Risikofaktoren und Arteriosklerose ist. Die respiratorische Gesundheit wurde mit
einer Messung des ausgeatmeten Stickstoffoxids (FeNO), einem Entzündungsmarker
in der Atemluft, und einem Lungenfunktionstest untersucht. Darüber hinaus wurden
beim ersten Termin ein Allergietest und jedes Mal ein ausführliches Interview
durchgeführt.
Für die Analyse der Gesundheitsdaten wurden mehrere Modelle entwickelt:
Einerseits wurde die Korrelation der Exposition mit den verschiedenen Parametern
vor Einführung des Rauchverbots in einer Querschnittsuntersuchung angeschaut.
Darüber hinaus wurde die Exposition in einem longitudinalen Modell zu jedem
Zeitpunkt mit den jeweiligen Gesundheitsdaten verglichen unter Berücksichtigung
der Tatsache, dass mehrere Untersuchungen von einer Person stammen konnten.
Als letztes wurde in einem Prä/Post?Modell ein Vergleich der Gesundheitsparameter
vor und nach dem Rauchgesetz gemacht ohne Berücksichtigung der
genauen Exposition. Die Modelle wurden jeweils für geeignete Kovariablen
adjustiert.
Der Verhaltens? und Akzeptanzfragebogen enthielt Fragen zum persönlichen
Wissenstand und zur Einstellung zum Rauchverbot, zu Faktoren, die diese
beeinflussen sowie zum Rauchstatus und –verhalten. Antworten wurden anhand
von angemessenen statistischen Tests verglichen.
Ergebnisse
Die durchschnittliche Rauchexposition in der Interventionsgruppe sank um 2.4
Zigarettenäquivalente/Tag nach dem Rauchverbot während die Veränderung in der
exponierten Kontrollgruppe signifikant kleiner war.
In einer Querschnittsuntersuchung der Baseline Daten wurde festgestellt, dass die
mittleren Lungenfunktionswerte der exponierten Gastgewerbemitarbeiter unter der
schweizerischen Durchschnittsbevölkerung lag. Die FeNO Werte waren direkt mit
der Exposition assoziiert, wobei eine Erhöhung der Exposition eine Verminderung
des Entzündungsmarkers bedeutete.
Im longitudinalen Modell, das die Exposition mit den Gesundheitsmassen verglich,
korrelierten mehrere HRV Parameter signifikant mit der Exposition. Die Abnahme
um ein Zigarettenäquivalent/Tag war mit einer Erhöhung der RMSSD
(Quadratwurzel der Summe der quadrierten Differenzen zwischen benachbarten
RR?Intervallen), der SDNN (Standardabweichung der RR?Intervalle), der HF? (High
Frequency) und der TP? (Total Power) Komponente verbunden, sowie mit einer
Abnahme der Pulswellengeschwindigkeit. Diese Assoziationen entsprachen der
ursprünglichen Hypothese, die eine bessere Gesundheit mit niedrigerer Exposition
voraussagte.
Im Prä/Post?Modell ohne Berücksichtigung der genauen Exposition wurde bei
mehreren Parametern eine signifikant unterschiedliche Entwicklung in der
Interventionsgruppe im Vergleich zur Kontrollgruppe gestellt. So stiegen SDNN,
RMSSD, HF, und TP in der Interventionsgruppe alle an, während sie in der
Kontrollgruppe absanken. Der HF/LF (High Frequency/Low Frequency) Quotient
verhielt sich umgekehrt, ein Effekt, der auch den Erwartungen entsprach. FeNO sank
in der Interventionsgruppe ab, während sich die Kontrollgruppe mit einem kleinen
Anstieg signifikant anders verhielt. Bei den Lungenfunktionsparametern konnte
keine Veränderung beobachtet werden.
Die Akzeptanz des Rauchverbots war von Anfang an höher bei den Nichtrauchern
als bei den Rauchern. Sie erhöhte sich jedoch in beiden Gruppen im Kanton Basel
Land, in dem ein umfassendes Rauchverbot eingeführt wurde, während das in den
andern beiden Kantonen, die Ausnahmen zuliessen, nicht der Fall war.
Diskussion
In dieser Studie wurden klare Anzeichen einer verbesserten kardiovaskulären
Gesundheit der nichtrauchenden Gastronomiemitarbeiter nach Einführung des
Rauchverbots gefunden. Die Risikofaktoren für einen Herzinfarkt oder eine
Arteriosklerose hatten sich in der Interventionsgruppe signifikant vermindert. Bei
der Lungenfunktion konnte keine Veränderung festgestellt werden während beim
FeNO zwar eine Abnahme beobachtet wurde, die jedoch nicht als klinisch relevant
betrachtet werden kann. Somit scheinen die Herzrhythmusvariabilität und die
Pulswellengeschwindigkeit die sensitivsten Marker zu sein, während die
Lungenfunktion womöglich entweder länger braucht, um sich zu erholen oder
dauerhaft geschädigt bleibt. FeNO wird von sehr vielen Faktoren beeinflusst und
sollte daher noch weiter erforscht werden.
All diese Resultate sprechen für ein umfassendes Rauchverbot ohne Ausnahmen. Die
erhöhte Akzeptanz dieser Form der Regelung, die wir fanden, unterstützt diese
Empfehlung weiter.
Trotzdem wurde eine Initiative der Lungenliga, die genau diese Vereinheitlichung
des Gesetzes verlangte, im September 2012 abgelehnt. Während des lebhaften
Abstimmungskampfes wurden auch erste Studienresultate publiziert. Der
Misserfolg der Kampagne wirft die Frage auf, ob Gesundheit als politisches
Argument attraktiv ist, wenn dabei eine Einschränkung der persönlichen
Entscheidungsfreiheit droht. Ausserdem muss die Rolle der Tabakindustrie, die in
der Schweiz als wichtiger Arbeitgeber und Steuerzahler eine übermächtige Stellung
hat, näher betrachtet und ins Bewusstsein der Bürger gerückt werden. Die
vermeintliche persönliche Freiheit der Schweizer über ihr Rauchverhalten zu
entscheiden scheint doch eher eine Selbsttäuschung zu sein, herbeigeführt mittels
einer verdeckten Gehirnwäsche durch die wohl manipulativste Industrie der Welt
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 text- …
