5,879 research outputs found

    Knowledge Rich Natural Language Queries over Structured Biological Databases

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    Increasingly, keyword, natural language and NoSQL queries are being used for information retrieval from traditional as well as non-traditional databases such as web, document, image, GIS, legal, and health databases. While their popularity are undeniable for obvious reasons, their engineering is far from simple. In most part, semantics and intent preserving mapping of a well understood natural language query expressed over a structured database schema to a structured query language is still a difficult task, and research to tame the complexity is intense. In this paper, we propose a multi-level knowledge-based middleware to facilitate such mappings that separate the conceptual level from the physical level. We augment these multi-level abstractions with a concept reasoner and a query strategy engine to dynamically link arbitrary natural language querying to well defined structured queries. We demonstrate the feasibility of our approach by presenting a Datalog based prototype system, called BioSmart, that can compute responses to arbitrary natural language queries over arbitrary databases once a syntactic classification of the natural language query is made

    A multi-family GLRT for detection in polarimetric SAR images

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    This paper deals with detection from multipolarization SAR images. The problem is cast in terms of a composite hypothesis test aimed at discriminating between the Polarimetric Covariance Matrix (PCM) equality (absence of target in the tested region) and the situation where the region under test exhibits a PCM with at least an ordered eigenvalue smaller than that of a reference covariance. This last setup reflects the physical condition where the back scattering associated with the target leads to a signal, in some eigen-directions, weaker than the one gathered from a reference area where it is apriori known the absence of targets. A Multi-family Generalized Likelihood Ratio Test (MGLRT) approach is pursued to come up with an adaptive detector ensuring the Constant False Alarm Rate (CFAR) property. At the analysis stage, the behaviour of the new architecture is investigated in comparison with a benchmark (but non-implementable) and some other adaptive sub-optimum detectors available in open literature. The study, conducted in the presence of both simulated and real data, confirms the practical effectiveness of the new approach

    Fall risk assessment in elderly with and without history of falls: kinematic gait analysis: a comparative study

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    Objectives: The objective of this research was to verify if there was a variation in the MFC (Minimum Foot Clearance) value among elderly with and without history of falls and, if there were any, verify which joint of the lower limb was responsible for that variation. It was also a main objective to verify if there was a correlation between the risk of falling, achieved through the Timed Up and Go Test (TUG), and the MFC variation. Material and Methods: The sample consisted of a total of 30 elderly who met the inclusion and exclusion criteria. These were divided into the group without history of falls (n=15) and into the group with history of falls (n=15). The MFC and the joint movement amplitudes of the hip, knee and ankle, of the dominant lower limb, were assessed using the Kinovea programme and for the risk of fall assessment it was used the TUG. Results: There were no statistically significant differences in the MFC and TUG values between the groups with and without history of falls. However, there is a decrease of the MFC value for the group with history of falls, being the ankle the joint that most contributed to the MFC variation in the group without history of falls, and the knee in the group with history of falls. About the relation between MFC and TUG, it was obtained a negative correlation (r=-0,269) but it was not significant (p=0,150). Conclusion: In our sample no significant differences in the MFC value were obtained between the group with history of falls and the group without history of falls. Besides the lack of significant differences in the MFC value it was determined the articulation of the lower limb responsible for its variation, and it has been found, although with a p>0,05, that for the group with no history of falls it was the ankle that more contributed to this variation and the knee to the group with history of falls. Concerning to the TUG and MFC value correlation it wasn’t significant. Thus, it was concluded that the TUG use is more effective and sensitive in predicting the risk of falling when compared with the kinematic analysis to obtain the MFC value and the joints amplitude

    Fall risk assessment in elderly with and without history of falls: strength analysis of lower limb: a comparative study

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    Objectives: The objective of this research was to analyse muscle performance criteria of the knee joints and ankle flexor and extensor muscles among elderly with and without history of falls. Material and methods: The sample was non-probabilistic, of convenience, comprising a total of 30 elderly (15 with history of falls and 15 without history of falls) who met the inclusion and exclusion criteria. Data were collected through a characterization questionnaire and through the Biodex System Isokinetic Dynamometer. The isokinetic assessment consisted in collecting the Peak Torque per unit of mass (N.m/BW) and ratio FlexorsCon/ExtensorsCon (%) of the knee joints and ankle flexor and extensor muscles, with 5 repetitions and the 60º/s angular speed. This collection has been made in both lower limbs. Results: The sample consisted of 30 individuals, 15 from the group without history of falls and 15 from the group with history of falls with average age of (69,17±4,77) years old. The muscle performance parameters were not significantly different between the groups (p>0,05). Conclusion: The group of elderly with history of falls showed lower Peak Torque numbers per unit of mass (N.m/BW) for the knee and ankle joint comparing with the group without history of falls. In present research also the values of the ratio flexorsCon/ExtensorsCon was analyzed weren't differences found in the knee and ankle joint. Although there are no statistically significant differences between results obtained, approach we believe it will be beneficial to include strengthening exercises for the flexors and extensors muscles of these joints, thereby contributing to the prevention of falls

    Fall risk assessment in elderly with and without history of falls: gait electromyographic analysis: a comparative study

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    Objectives: To determinate if there were differences in electromyography parameters of rectus anterior, biceps femoris, gluteus medius, soleus, gastrocnemius medialis and tibialis anterior muscles between group with and without history of falls during. Was analized the relationship between the levels of muscle activation and score in POMA (Performance-Oriented Mobility Assessment). Materials and Methods: This is a transversal, not experimental and comparative study. The sample was composed by 30 older adults, 15 with and 15 without history of falls. To collect the data of electromyography was used BIOPAC systems and followed the SENIAM guidelines. For the collection of kinematic data was used Kinovea program and for assess the risk of falling was applied POMA. Results: Individuals with history of falls present levels of muscle activity relatively to maximum voluntary contraction (MVC) higher in the dominant lower limb (right) compared to subjects without a history of falls, however these differences aren´t statistically significant (p>0,05). There is enormous variation between the sample in relation to phases of gait in which the muscles are more actives. The group with history of falls shows values lower than group without history of falls in POMA score, the difference is significant (p=0.001). The relationship between percentage of muscle activation and the values obtained in POMA not proved statistically significant (p>0,05). Conclusion: Although results obtained weren´t statistically significants, we can conclude that individuals with falls have higher levels of muscle activation relative to MVC that individuals without history of falls, it is believed that the changes are related to the development of strategies for increased stability during gait. There is considerable variability in phases in which the subjects engaged higher levels of muscle activation, which might occur due to task compensatory strategies or by the task have been made at speed of comfort for the individual. It follows that POMA is an instrument more sensitive and effective to identify the risk of falling in these individuals that the electromyographic analysis

    Fall risk assessment in elderly with and without history of falls: relationship between disorders of balance, fear of falling and gait changes: a comparative study

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    Objectives: The aim of this study was to assess the changes that occur in the balance, fear of falling and kinematic parameters such as stride length, velocity and time support in elderly with and without a history of falling. Main objective was also to verify whether a relationship exists between changes in gait parameters evaluated, balance and fear of falling. Methods: The sample comprised 30 patients (15 with history of falls and 15 without a history of falls), which met the criteria for inclusion and exclusion. The kinematic evaluation was performed in the dominant leg, which was right in this sample. The stride length, speed and duration of support were assessed using the program Kinovea and for assessment of balance and fear of falling were assessed using the Berg Balance Scale and the Falls Efficacy Scale. Statistical analysis was performed with SPSS version 20. Results: There were no significant differences in the parameters analyzed, except for scores on the Berg Balance Scale (p=0.000) between groups with and without history of falls. However, there is a decrease in the length of the stride and duration of left leg support and the increased length of right leg support, the speed and the fear of falling. The relationship between the parameters obtained, there is only statistically significant result between speed and stride length (r=0.507, p=0.004) and between the score of the Berg Balance Scale and the stride length (r=0.393, p=0,032). Conclusion: Although not having obtained statistically significant results we can conclude that in elderly with a history of falls have changes in speed and stride length that can be related to balance disorders and the aging process itself. However, it is concluded that the use of the Berg Balance Scale is more responsive and effective in the detection of changes occurring in the individual after a fall, and subsequent evaluation of the risk of falling that performing a kinematic analysis

    Private Fingerprint Verification without Local Storage

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    From Sensing to Action: Quick and Reliable Access to Information in Cities Vulnerable to Heavy Rain

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    Cities need to constantly monitor weather to anticipate heavy storm events and reduce the impact of floods. Information describing precipitation and ground conditions at high spatio-temporal resolution is essential for taking timely action and preventing damages. Traditionally, rain gauges and weather radars are used to monitor rain events, but these sources provide low spatial resolutions and are subject to inaccuracy. Therefore, information needs to be complemented with data from other sources: from citizens' phone calls to the authorities, to relevant online media posts, which have the potential of providing timely and valuable information on weather conditions in the city. This information is often scattered through different, static, and not-publicly available databases. This makes it impossible to use it in an aggregate, standard way, and therefore hampers efficiency of emergency response. In this paper, we describe information sources relating to a heavy rain event in Rotterdam on October 12-14, 2013. Rotterdam weather monitoring infrastructure is composed of a number of rain gauges installed at different locations in the city, as well as a weather radar network. This sensing network is currently scarcely integrated and logged data are not easily accessible during an emergency. Therefore, we propose a reliable, efficient, and low-cost ICT infrastructure that takes information from all relevant sources, including sensors as well as social and user contributed information and integrates them into a unique, cloud-based interface. The proposed infrastructure will improve efficiency in emergency responses to extreme weather events and, ultimately, guarantee more safety to the urban population
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