Добірка наукової літератури з теми "Localisation ambiguity"

We applied motion theory to robot audition to improve the inadequate performance. Motions are critical for overcoming the ambiguity and sparseness of information obtained by two microphones. To realise this, we first designed a sound source localisation system integrated with cross-power spectrum phase (CSP) analysis and an EM algorithm. The CSP of sound signals obtained with only two microphones was used to localise the sound source without having to measure impulse response data. The expectation-maximisation (EM) algorithm helped the system to cope with several moving sound sources and reduce localisation errors. We then proposed a way of constructing a database for moving sounds to evaluate binaural sound source localisation. We evaluated our sound localisation method using artificial moving sounds and confirmed that it could effectively localise moving sounds slower than 1.125 rad/s. Consequently, we solved the problem of distinguishing whether sounds were coming from the front or rear by rotating and/or tipping the robot's head that was equipped with only two microphones. Our system was applied to a humanoid robot called SIG2, and we confirmed its ability to localise sounds over the entire azimuth range as the success rates for sound localisation in the front and rear areas were 97.6% and 75.6% respectively.

A method for damage localisation has been developed, which is based on the phased array idea. Four arrays of transducers, instead of only one, are used to perform a beam-forming procedure. Each array consists of nine transducers placed along a line, which are able to excite and register elastic waves. The arrays are placed in such a way that the angular difference between them is 45º and the rotation point is the middle transducer, which is common for all the arrays. The idea has been tested on a square aluminium plate modelled by the Spectral Finite Element Method. Two types of damage were considered, namely distributed damage, which was modelled as stiffness reduction, and cracks, modelled as separation of nodes in selected finite elements. The plate is excited by a wave packet (5-cycle sine modulated by the Hanning window). The whole array system is placed in the middle of the plate. Each phase array in the system acts independently and produces maps of a scanned field based on the beam-forming procedure. These maps are made of signals that represent the difference between the damaged plate signals and those from the intact plate. An algorithm was developed to join all four maps. This procedure eliminates the necessity to analyse each map individually and also gives the possibility to extract common features only. It allows to remove ambiguity and helps to localise damage more precisely than in the case of a single map. The problem for damage localisation was investigated and exemplary maps confirming the effectiveness of the system proposed were obtained. The investigation is based exclusively on numerical data.

The ambiguity of the causal relationship between knowledge creation and regional growth does not indicate its insignificance, as proven by numerous empirical studies. However, such works rarely examine small towns, characterised by uncertainty of knowledge sources. The article aims to identify and compare groups of similar small towns in the Central, Ural and Southern Federal Districts by using a set of knowledge localisation factors. A two-stage clustering was performed by the k-means method according to the following criteria: interactions between actors, specific knowledge stock and financial resources for commercialisation. The resulting cluster centres were divided into quartiles according to the grading system (good, satisfactory or poor). First, the study revealed 10 clusters in the Central Federal District, 7 clusters in the Ural Federal District and 5 clusters in the Southern Federal District. In 35 % of the towns of the Southern Federal District, 35 % of the Central Federal District and 38 % of the Ural Federal District, the estimated specific knowledge stock exceeded the availability of financial resources. Second, towns were differentiated by population and divided into two groups depending on the agglomeration impact of larger cities. Clusters were formed within each group and federal district. 50 % of Ural towns with a population of 10,000 to 20,000 people unaffected by the agglomeration, as well as 62 % of towns with more than 20,000 people have the advantage of specific knowledge stock over financial resources. These values are 18 % and 8 %, respectively, for the Central Federal District, 36 % and 30 % for the Southern Federal District. The findings can help extend the analytical framework for making decisions on the small towns development. Future research may focus on establishing measures to improve the characteristics of clusters.

A visual stimulus typically activates several cortical areas, both sequentially and overlapping in time. Characterisation of this temporal activation sequence has significantly improved with the recent development of whole-scalp neuromagnetometers. The magnetoencephalographic (MEG) signals mainly arise from time-locked cortical activity. Although the spatial localisation of several simultaneously active areas is ambiguous because of the non-uniqueness of the inverse problem, the comparison of estimated source regions across observers and utilisation of previous functional knowledge can usually resolve this ambiguity. Visual object naming, for example, generates cortical activation progressing bilaterally from occipital to temporal and frontal lobes. Simultaneously, the parieto-occipital alpha rhythm dampens as a function of task demands. Similarly, this rhythm is at a lower level after objects than non-objects in an object-detection task, which suggests that the parieto-occipital area is active when attending to visual form. In addition, this area generates evoked responses after voluntary blinks, saccades, and luminance increments, which in turn suggests that it participates in the updating of visual percepts. The sources of extrastriate MEG signals are generally in good agreement with the location of activation found with other imaging methods: visual motion activates the V5 in the ascending limb of the inferior temporal sulcus, faces the ventral temporo-occipital cortex, and objects the lateral occipital (LO) regions. Interestingly, the strength of the right LO activity closely follows the proportion of correctly detected objects. The future neuromagnetic studies will focus not only on functional localisation of the active areas, but also on how the brain processes various stimuli.

There has been a renewed interest in the debates on the use of force. This resurgence in academic and policy circles can be attributed to the new wave of military interventions after the initial hiatus of the Global War on Terror period. The recent cases of the use of force are once again raising pertinent legal questions regarding the responsibility for the maintenance of international peace and security which is vested in the United Nations Security Council (UNSC) by the United Nations (UN) Charter. This authority, exemplified by the UNSC control of the use of force has been challenged by unilateral recourse to force by States, coalitions of States and regional organisations. The African Union (AU) has developed regional legal frameworks which may contest some established legal norms on the use of force, including the primary responsibility of the UNSC to authorise the use of force for the maintenance of international peace and security. In this article, I delineate these norm contestations and identify specific modes of such contestations in UNSC-AU relationship within the frameworks of their respective constitutive treaties. I draw on the idea of norm localisation and subsidiarity to understand the African Union’s approach to its relationship with the UNSC, the ways in which these norm contestations impact that relationship and how the contestations affect the norm on the use of force.

L'objet des travaux de cette thèse est de proposer de nouveaux processus de définition de tests (testabilité), de nouvelles méthodes de tests, ainsi que de nouvelles méthodes d'interprétation des tests (diagnostic). Ces travaux ont été menés dans le cadre de l'aéronautique et ont porté dans un premier temps sur l'identification des besoins en diagnostic des hélicoptères. Les problématiques liées au test et au diagnostic des hélicoptères portaient sur : - La non-détection de certaines défaillances - L'occurrence de nombreuses fausses alarmes - L'ambiguïté de localisation de défaillances Dans un premier temps nous avons réalisé l'état de l'art des recherches en diagnostic, ceci afin de sélectionner les technologies et méthodologies permettant de répondre aux problématiques identifiées. Les technologies candidates ont ensuite été architecturées afin de proposer un traitement intégré permettant de répondre à l'ensemble des besoins identifiés. Ainsi nous avons travaillé sur les méthodologies de définition du test, aux moyens d'outils de simulation de la testabilité. Nous avons aussi défini de nouvelles méthodes de test permettant de déterminer l'état de capteurs analogiques aux moyens d'algorithmes basés sur des évaluateurs de calcul de variation de l'écart type, du facteur de forme et du rapport signal sur bruit. Nous avons ensuite travaillé sur l'amélioration du diagnostic au niveau système à l'aide d'automates temporisés afin de simuler le fonctionnement des arbres de tests élémentaires. Ces travaux ont ensuite conduit à la modélisation et au diagnostic des systèmes complexes à l'aide des diagrammes d'état, des arbres de défaillances dynamiques, ainsi que leur simulation à l'aide des réseaux de Petri. Les modèles utilisés ont été complétés au moyen de nouvelles portes dynamiques. Ces travaux ont été appliqués au monde aéronautique, sur plusieurs hélicoptères et ont fait l'objet de deux brevets
The object of the work of this thesis is to propose new processes of definition of tests (testability), new methods of tests, as well as new methods of tests interpretation (diagnosis). This work was carried out in the framework of aeronautics. It first intends to identify the needs of the helicopter diagnosis. The identified problems, related to the test and the diagnosis of the helicopters, were: - Non-detection of failures - Occurrence of many false alarms - Failure localisation ambiguity We first achieved the state of the art of research in diagnosis, in order to select technologies and methodologies allowing to answer the problematic. Candidate technologies were then structured in order to propose an integrated treatment. Thus we worked on methodologies of definition of the test, with testability simulation tools. We also defined new methods of test which allows determining the status of analogue sensors with the means of algorithms based on the calculus of variation of the standard deviation, form factor and noise-signal ratio. We then worked on the improvement of the diagnosis at system level using timed automata in order to simulate the operation of the tests tree. This work then led to the modelling of the complex systems using state diagram, dynamic fault trees, as well as their simulation with Petri networks. Additional doors were defined to complete the existing algorithms. Finally, this work was applied to the aeronautical world, to several helicopters and was the subject of two patents

L'objet des travaux de cette thèse est de proposer de nouveaux processus de définition de tests (testabilité), de nouvelles méthodes de tests, ainsi que de nouvelles méthodes d'interprétation des tests (diagnostic). Ces travaux ont été menés dans le cadre de l'aéronautique et ont porté dans un premier temps sur l'identification des besoins en diagnostic des hélicoptères. Les problématiques liées au test et au diagnostic des hélicoptères portaient sur : - La non-détection de certaines défaillances - L'occurrence de nombreuses fausses alarmes - L'ambiguïté de localisation de défaillances Dans un premier temps nous avons réalisé l'état de l'art des recherches en diagnostic, ceci afin de sélectionner les technologies et méthodologies permettant de répondre aux problématiques identifiées. Les technologies candidates ont ensuite été architecturées afin de proposer un traitement intégré permettant de répondre à l'ensemble des besoins identifiés. Ainsi nous avons travaillé sur les méthodologies de définition du test, aux moyens d'outils de simulation de la testabilité. Nous avons aussi défini de nouvelles méthodes de test permettant de déterminer l'état de capteurs analogiques aux moyens d'algorithmes basés sur des évaluateurs de calcul de variation de l'écart type, du facteur de forme et du rapport signal sur bruit. Nous avons ensuite travaillé sur l'amélioration du diagnostic au niveau système à l'aide d'automates temporisés afin de simuler le fonctionnement des arbres de tests élémentaires. Ces travaux ont ensuite conduit à la modélisation et au diagnostic des systèmes complexes à l'aide des diagrammes d'état, des arbres de défaillances dynamiques, ainsi que leur simulation à l'aide des réseaux de Petri. Les modèles utilisés ont été complétés au moyen de nouvelles portes dynamiques. Ces travaux ont été appliqués au monde aéronautique, sur plusieurs hélicoptères et ont fait l'objet de deux brevets.

AbstractThe human rights regime—as law, institutions and practice—has been facing criticism for decades regarding its effectiveness, particularly in terms of unsatisfactory overall implementation and the failure to protect the most vulnerable who do not enjoy the protection of their States: refugees. Turkey is the country hosting the largest refugee population, with around four million at the end of May 2020 (https://www.unhcr.org/tr/wp-content/uploads/sites/14/2020/06/UNHCR-Turkey-Operational-Update-May-2020.pdf). As an administratively centralised country, Turkey’s migration policy is implemented by central government agencies, but this has not proved sufficient to guarantee the human rights of refugees on the ground. Meanwhile, in connection with urbanisation, decentralisation and globalisation, local governments around the world are receiving increasing attention from migration studies, political science, law, sociology and anthropology. In human rights scholarship, the localisation of human rights and the potential role of local governments have been presented as ways to counter the shortcomings in the effectiveness of the human rights regime and discourse. While local governments may have much untapped potential, a thorough analysis of the inequalities between local governments in terms of access to resources and opportunities is essential. The Turkish local governments which form the basis of this research, operate in a context of legal ambiguity concerning their competences and obligations in the area of migration. They also have to deal with large differences when it comes to resources and workload. In practice, therefore, there is extreme divergence amongst municipalities in the extent to which they engage with refugee policies. This chapter seeks to answer the question why and how certain local governments in Turkey come to proactively engage in policy-making that improves the realisation of refugees’ rights. Exploratory grounded field research among Turkish local governments reveals four main factors that enable and facilitate the engagement of local governments in refugee policies: (1) the capacity of and institutionalisation in local governments; (2) the dissemination of practices and norms surrounding good local migration and rights-based governance through networks; (3) the availability of cooperation and coordination with other actors in the field, and (4) political will. Collectively, these factors illustrate how a new norm—the norm that local governments can and ought to engage in policy-making improving the rights of refugees—is cross-pollinating and taking root among Turkish local governments. This understanding will provide valuable insights into how norms are developed, travel and are institutionalised within social and institutional networks, and how differences in access, capacity, political and cooperative opportunities may facilitate and obscure the path to policies improving human rights on the ground.