91 research outputs found
Consensus based distributed detection and estimation algorithms
Ова дисертација разматра неколико важних проблема у дистрибуираној обради сигнала, то јест, у дистрибуираној детекцији и естимацији сигнала...This work deals with several important problems of distributed signal processing,
i.e., distributed signal detection and estimation. Novel algorithms for distributed
change detection and target tracking using sensor networks, as well as algorithm for
fault detection and isolation using overlapping system decomposition are proposed.
All the proposed algorithms are based on the introduction of a consensus strategy,
whose dynamics is combined in parallel with detection or estimation dynamics,
enforcing in such a way agreement between the sensors of the used sensor networks
or between overlapping subsystems of the monitored systems, and obtaining robust
and ecient solutions of the considered problems.
In the rst part a novel distributed algorithm derived from the Generalized Likelihood
Ratio is proposed for real time change detection using sensor networks. The
algorithm is based on a combination of recursively generated local statistics and a
global consensus strategy, and does not require any fusion center. The problem of
detection of an unknown change in the mean of an observed random process is discussed
and the performance of the algorithm is analyzed in the sense of a measure
of the error with respect to the corresponding centralized algorithm. The analysis
encompasses asymmetric constant and randomly time varying matrices describing
communications in the network, as well as constant and time varying forgetting
factors in the underlying recursions. An analogous algorithm for detection of an
unknown change in the variance is also proposed. Simulation results illustrate characteristic
properties of the algorithms including detection performance in terms of
detection delay and false alarm rate. They also show that the theoretical analysis
connected to the problem of detecting change in the mean can be extended to the
problem of detecting change in the variance.
A new distributed fault detection and isolation (FDI) methodology is proposed
in the second part, in the form of a multi-agent network representing a combination
of a consensus based FDI observer for residual generation and a consensus based
decision making strategy for change detection, applicable in real time. The proposed
observer is based on overlapping system decomposition and a combination between
the local optimal stochastic FDI observers and a dynamic consensus strategy. It
is shown how the proposed algorithm can generate residuals which provide, under
general conditions concerning local models and the network topology, high eciency,
scalability and robustness. The proposed decision making strategy provides solutions
for two particular cases: a) local detection for non-overlapping parts of the identied subsystems; b) a consensus based strategy for FDI in the overlapping parts. Selected examples illustrate the applicability of the proposed methodology in practice..
Change the Context of the Peace Institute Action after the Cold War
Članak se bavi razvojem i društvenom ulogom mirovnih instituta tokom trajanja Hladnog rata i nakon njegovog završetka. Razlozi nastanka, specijalizacije i porasta broja mirovnih instituta tumače se kroz uticaj političkog, ekonomskog i ideološkog aspekta hladnoratovskog okruženja. Kroz pet specifičnih faza prikazuje se razvoj institucionalizacije istraživanja mira. U članku se zastupa teza da je hladnoratovsko okruženje pogodovalo razvoju mirovnih instituta i da su promenjeni ekonomski i politički uslovi krajem Hladnog rata uticali da globalni značaj mirovnih instituta opadne iako društvene potrebe za njima nisu smanjene nestankom bipolarnog poretka.The article deals with development and the social role of peace institute during
the Cold War and after its end. Reasons for the creation, specialization and growth of the
number of peace institutes are interpreted through the influence of the political, economic
and ideological aspect of the Cold War environment. The development of the
institutionalization of peace research is shown through five specific stages. The paper
presents the thesis that the Cold War environment favored the development of peace
institutes, and that the changed economic and political conditions at the end of the Cold
War induced the reduction of the global importance of peace institutes even though the
social needs for them have not decreased with the disappearance of a bipolar order
DETECTION OF TEXTURE-LESS OBJECTS BY LINE-BASED APPROACH
This paper proposes a method for tackling the problem of scalable object instance detection in the presence of clutter and occlusions. It gathers together advantages in respect of the state-of-the-art object detection approaches, being at the same time able to scale favorably with the number of models, computationally efficient and suited to texture-less objects as well. The proposed method has the following advantages: a) generality – it works for both texture-less and textured objects, b) scalability – it scales sub-linearly with the number of objects stored in the object database, and c) computational efficiency – it runs in near real-time. In contrast to the traditional affine-invariant detectors/descriptors which are local and not discriminative for texture-less objects, our method is based on line segments around which it computes semi-global descriptor by encoding gradient information in scale and rotation invariant manner. It relies on both texture and shape information and is, therefore, suited for both textured and texture-less objects. The descriptor is integrated into efficient object detection procedure which exploits the fact that the line segment determines scale, orientation and position of an object, by its two endpoints. This is used to construct several effective techniques for object hypotheses generation, scoring and multiple object reasoning; which are integrated in the proposed object detection procedure. Thanks to its ability to detect objects even if only one correct line match is found, our method allows detection of the objects under heavy clutter and occlusions. Extensive evaluation on several public benchmark datasets for texture-less and textured object detection, demonstrates its scalability and high effectiveness
On ultimate strength of an inland waterway barge
Due to the sudden nature of hull girder collapse caused by extreme loadings, the ultimate strength of ships, i.e., ultimate capacity, has to be evaluated. Ultimate strength analysis procedures have already been provided within the rules of the classification societies for sea-going ships. However, rules for inland vessels are not fully addressing the issue. In addition, literature data on the ultimate strength of inland vessels are almost negligible, which is alarming, considering the frequency of grounding and overloading events in inland navigation. Moreover, inland vessels' structural elements are prone to buckling due to their slender plates. In order to evaluate ultimate strength, an inland waterway (IW) barge is chosen for progressive collapse analysis (PCA) employment. PCA has demonstrated that the buckling collapse of structural elements vastly governs a vessel's ultimate capacity. Results show the extent of the safety zone between the actual loss of the ultimate capacity and the linear-elastic behavior of the structure
An Analysis of Energy Efficient Data Transfer between Mobile Device and Dedicated Server
This paper discusses research results with regard to energy-efficient transmission of serialised data between servers and mobile devices. A test environment was created in which the research authors primarily measured electricity consumption during communication between a mobile device and server. Numerical results were used to determine how well data serialisation was performed on a dedicated server and its effects on the power consumption of a mobile device. The time spent in data serialisation and the size of the serialised file were found to significantly influence energy consumption. Based on that fact, results have been used to create a mathematical model which was later introduced with functional forms. The main variables in those functional forms were time of serialisation and size of a serialised file. The data collected through this research has been used for an experimental API-CB Saver, which based on mathematical models chooses the most favourable manner of serialisation and compression in real time. The results collected during the tests show that the CBSaver-Api approach performs with greater energy efficiency than current techniques. Furthermore, with optimal selection of data serialisation type and compression level in real time the considered system shows better performance in power saving. According to the results, the API-CBSaver tests indicate the direction which one should take for the purposes of improving energy efficiency
Welfare of Native Goat Breeds in Serbia—Emphasis on Parasitological Infections
Native goat breeds in Serbia has been recognized as an important element of regional agrobiodiversity and play an important role in the safeguarding of cultural and traditional heritage. The aim of this study was to identify the main welfare issues likely to be encountered in extensive goat farming systems with an emphasis on parasitological infections. The study was conducted during the winter season on four small farms of native Balkan and Serbian white goats. For welfare assessment, animal-based indicators from AWIN protocol for goats were used. All fecal samples for parasites were qualitatively and quantitatively examined. The main welfare issues identified were poor hair coat condition (62.79%), dirty and light soiling hindquarters (31.40%), thin body condition score (26.74%), abscesses (19.78%), and udder asymmetry (18.60%). In addition, an important and prevalent welfare problem identified across all farms was parasite infection and weak significant (p < 0.001) correlation between certain parasites (Strongylidae, Moniezia spp., Buxtonella sulcate, and Protostrongylidae) and welfare indicators such as poor hair coat condition and nasal discharge. The results of this study provided the first overview and valuable insight into the impact of extensive systems on the welfare of native goats in the Balcan region
Multi-objective fuzzy optimization of sizing and location of piezoelectric actuators and sensors for vibration control based on the particle swarm optimization technique: Part 2: Numerical analysis
Ovo je drugi deo istraživanja višeciljne fazi optimizacije veličine i položaja piezoelektričnih aktuatora i senzora na tankozidnoj kompozitnoj gredi. Prvi rad je fokusiran na teorijskom modelu optimizacione tehnike za optimalno dimenzionisanje i postavljanje piezoelektičnih aktuatora i senzora na pametnu strukturu za aktivno upravljanje vibracijama. U ovom delu, biće prikazana numerička analiza predstavljene optimizacione tehnike za kompozitnu konzolu sa i bez ograničenja u pogledu stepena upravljivosti za rezidualne modove.This is the second part of a two-paper research of the multi-objective fuzzy optimization of sizing and location of the collocated piezoelectric actuators and sensors on the thin-walled composite beam. The first paper is focussed on the theoretical model of a optimization techique for optimal sizing and location of piezoelectric actuators and sensors on a smart structure for active vibration control. In this part, the numerical analysis of the presented optimization technique will be presented for the cantilever composite beam with and without limitations in degrees of controllability (DCs) for residual modes
Multi-objective fuzzy optimization of sizing and location of piezoelectric actuators and sensors for vibration control based on the particle swarm optimization technique: Part 2: Numerical analysis
Ovo je drugi deo istraživanja višeciljne fazi optimizacije veličine i položaja piezoelektričnih aktuatora i senzora na tankozidnoj kompozitnoj gredi. Prvi rad je fokusiran na teorijskom modelu optimizacione tehnike za optimalno dimenzionisanje i postavljanje piezoelektičnih aktuatora i senzora na pametnu strukturu za aktivno upravljanje vibracijama. U ovom delu, biće prikazana numerička analiza predstavljene optimizacione tehnike za kompozitnu konzolu sa i bez ograničenja u pogledu stepena upravljivosti za rezidualne modove.This is the second part of a two-paper research of the multi-objective fuzzy optimization of sizing and location of the collocated piezoelectric actuators and sensors on the thin-walled composite beam. The first paper is focussed on the theoretical model of a optimization techique for optimal sizing and location of piezoelectric actuators and sensors on a smart structure for active vibration control. In this part, the numerical analysis of the presented optimization technique will be presented for the cantilever composite beam with and without limitations in degrees of controllability (DCs) for residual modes
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