Transparent Location Fingerprinting for Wireless Services

Detecting the user location is crucial in a wireless environment, not only for the choice of first-hop communication partners, but also for many auxiliary purposes: Quality of Service (availability of information in the right place for reduced congestion/delay, establishment of the optimal path), energy consumption, automated insertion of location-dependent info into a web query issued by a user (for example a tourist asking informations about a monument or a restaurant, a fireman approaching a disaster area). The technique we propose in our investigation tries to meet two main goals: transparency to the network and independence from the environment. A user entering an environment (for instance a wireless-networked building) shall be able to use his own portable equipment to build a personal map of the environment without the system even noticing it. Preliminary tests allow us to detect position on a map with an average uncertainty of two meters when using information gathered from three IEEE802.11 access points in an indoor environment composed of many rooms on a 625sqm area. Performance is expected to improve when more access points will be exploited in the test area. Implementation of the same techniques on Bluetooth are also being studied

Do not be afraid of local minima: affine shaker and particle swarm

Stochastic local search techniques are powerful and flexible methods to optimize difficult functions. While each method is characterized by search trajectories produced through a randomized selection of the next step, a notable difference is caused by the interaction of different searchers, as exemplified by the Particle Swarm methods. In this paper we evaluate two extreme approaches, Particle Swarm Optimization, with interaction between the individual "cognitive" component and the "social" knowledge, and Repeated Affine Shaker, without any interaction between searchers but with an aggressive capability of scouting out local minima. The results, unexpected to the authors, show that Affine Shaker provides remarkably efficient and effective results when compared with PSO, while the advantage of Particle Swarm is visible only for functions with a very regular structure of the local minima leading to the global optimum and only for specific experimental conditions

Statistical Learning Theory for Location Fingerprinting in Wireless LANs

In this paper, techniques and algorithms developed in the framework of statistical learning theory are analyzed and applied to the problem of determining the location of a wireless device by measuring the signal strengths from a set of access points (location fingerprinting). Statistical Learning Theory provides a rich theoretical basis for the development of models starting from a set of examples. Signal strength measurement is part of the normal operating mode of wireless equipment, in particular Wi-Fi, so that no custom hardware is required. The proposed techniques, based on the Support Vector Machine paradigm, have been implemented and compared, on the same data set, with other approaches considered in the literature. Tests performed in a real-world environment show that results are comparable, with the advantage of a low algorithmic complexity in the normal operating phase. Moreover, the algorithm is particularly suitable for classification, where it outperforms the other techniques

Internet et intranet à la bibliothèque municipale à vocation régionale de Troyes

This paper presents a memory-based Reactive Affine Shaker (M-RASH) algorithm for global optimization. The Reactive Affine Shaker is an adaptive search algorithm based only on the function values. M-RASH is an extension of RASH in which good starting points to RASH are suggested online by using Bayesian Locally Weighted Regression (B-LWR). Both techniques use the memory about the previous history of the search to guide the future exploration but in very different ways. RASH compiles the previous experience into a local search area where sample points are drawn, while locally-weighted regression saves the entire previous history to be mined extensively when an additional sample point is generated. Because of the high computational cost related to the B-LWR model, it is applied only to evaluate the potential of an initial point for a local search run. The experimental results, focussed onto the case when the dominant computational cost is the evaluation of the target $f$ function, show that M-RASH is indeed capable of leading to good results for a smaller number of function evaluations

Sentence Complexity in Context

We study the influence of context on how humans evaluate the complexity of a sentence in English. We collect a new dataset of sentences, where each sentence is rated for perceived complexity within different contextual windows. We carry out an in-depth analysis to detect which linguistic features correlate more with complexity judgments and with the degree of agreement among annotators. We train several regression models, using either explicit linguistic features or contextualized word embeddings, to predict the mean complexity values assigned to sentences in the different contextual windows, as well as their standard deviation. Results show that models leveraging explicit features capturing morphosyntactic and syntactic phenomena perform always better, especially when they have access to features extracted from all contextual sentences

Efeitos do ômega-3 nas doenças cardiovasculares: uma revisão

Monografia apresentada ao setor de Pós-Graduação da Universidade do Extremo Sul Catarinense – UNESC, para a obtenção do titulo de especialista em Nutrição Clinica.Os ácidos graxos são cadeia de carbono, usualmente de 12 a 24, que apresentam um radical alfa (ácido carboxílico) e um ômega (metila ou n). Logo os ácidos graxos ômega-3 são termos genéricos que se referem a um conjunto de lipídios que apresentação a primeira insaturação, ou dupla ligação das cadeias de carbono a partir do ômega. Os ácidos graxos ômega-3 são essenciais ao organismo, principalmente pelas propriedades funcionais que apresentam. A presente pesquisa tratou-se de um estudo de revisão bibliográfica, pois permitiu proporcionar maior familiaridade com o tema estudado, o mesmo envolveu a utilização de artigos científicos, dissertações, livros e teses. Esta revisão bibliográfica pretendeu verificar e analisar desta forma os efeitos do uso de ômega-3 nas quantidades necessárias para a prevenção e tratamento de indivíduos com doenças cardiovasculares, através de um estudo aprofundado em trabalhos científicos sobre suas relações com a alimentação e as doenças cardiovasculares. Diversos estudos têm evidenciado a relação entre características qualitativas e quantitativas da dieta rica em ácidos graxos ômega-3 e a ocorrência de enfermidades crônica, demonstraram ainda que o consumo de quantidades relativamente pequenas destes ácidos graxos pode prevenir deficiências nutricionais e a substituição da gordura saturada da dieta pode diminuir o risco de doenças crônicas degenerativas. Os alimentos de origem marinha são ricos em ômega-3, principalmente o ácido eicosapentaenóico (EPA) e ácido docosahexaenóico (DHA), que possuem funções importantes na prevenção de ataques cardíacos. Porém, os indivíduos têm mudado seus hábitos alimentares para uma dieta contendo mais gordura saturada, e menor quantidade de ômega-3. Os ácidos graxos ômega-3 são fundamentais durante toda a vida, pois exerce efeito cardioprotetor no organismo

Eversion of the Third Eyelid Cartilage in a Cat

Background: Eversion of the cartilage of the third eyelid is a rare congenital disease in cats. It is caused by the anterior eversion of the cartilage edge of the third eyelid. Clinical signs may be associated with secondary keratoconjunctivitis, third eyelid gland protrusion, and ocular surface irritation. The diagnosis is made by ophthalmic examination, and treatment consists of surgical resection of the everted cartilage portion. The goal of the present study was to report a case of eversion of third eyelid cartilage in a cat, given that it is an unusual abnormality in this animal species, and an important differential diagnosis to be considered in the disorders of the third eyelid.Case: A 6-year-old neutered female Persian cat was presented with a presumptive diagnosis of protrusion of the third eyelid gland, history of ocular irritation, and epiphora in the left eye. The disorder had been intermittently present since the animal was 1-year-old, with spontaneous disappearance after approximately 15 days. The owner related the reappearance of the disorder to stressful situations, with no previous history of trauma or other ocular alteration. During the ophthalmic examination, suspended solute was observed through biomiscroscopic examination in both eyes, as well as an increase in volume of the third eyelid in the left eye, without other changes. A thorough examination, under general anesthesia, indicated the protruding volume of the cartilage of the everted third eyelid. The third eyelid was pleated in its upper portion, demonstrating that the cartilage of the third eyelid was folded instead of following the curvature of the ocular surface. Under general anesthesia, the cartilage was partially removed through two parallel incisions on the bulbar conjunctival surface, divulsioning 5 mm in length in the vertical portion of the cartilage in a ‘T’ shape, and separating the conjunctiva from the underlying cartilage. The everted portion of cartilage, once removed, was in fact considered curved in its most dorsal portion, in a manner similar to what was reported in dogs. The third eyelid returned to its anatomically correct position after removing the deformed portion of the cartilage. The patient was treated postoperatively with topical drops of tobramycin and dexamethasone 3 mg/mL + 1 mg/mL (Tobradex®), and lubricant based on sodium hyaluronate 2 mg/mL (Hylo®-Gel). No complications were observed in the postoperative consultations during a 8 month follow-up.Discussion: It is suspected that the eversion of the third eyelid cartilage occurs due to a differential growth rate between the posterior and anterior portions of the cartilage; even though other theories have been proposed. The cartilage of the third eyelid can commonly be everted in large dog breeds, being classified as a disease of hereditary character. However, it has rarely been reported in cats, which can be explained by the more elastic histological constitution when compared to that of dogs. The surgical procedure performed in the present case of eversion of the third eyelid cartilage in a cat was in accordance with that described in the literature. Complete recovery of the third eyelid function was achieved, and the patient's ocular health was preserved. The reported case showed a favorable prognosis after diagnosis, associated with correct treatment and postoperative management. Although there was an effective recovery of the third eyelid, the issues related to the pathophysiology of cartilage eversion are unknown. This way, further studies are necessary to elucidate its etiology

Is this sentence difficult? Do you agree?

In this paper, we present a crowdsourcing-based approach to model the human perception of sentence complexity. We collect a large corpus of sentences rated with judgments of complexity for two typologically-different languages, Italian and English. We test our approach in two experimental scenarios aimed to investigate the contribution of a wide set of lexical, morpho-syntactic and syntactic phenomena in predicting i) the degree of agreement among annotators independently from the assigned judgment and ii) the perception of sentence complexity