47 research outputs found

    An analysis on the impact of geolocation in recommending venues in location-based social networks

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    The pervasiveness of geo-located devices has opened new possibilities in recommender systems on social networks. In effect, Location-Based Social Networks or LBSNs are a relatively new breed of social networks that let users share their location by triggering ”check-in” events on venues, such as businesses or historical places. In this paper, we compare the performance of traditional rating and social-based similarity metrics against location-based metrics in a userbased collaborative filtering algorithm that recommends venues or places to visit. This analysis was performed on a large real-world dataset provided by the Yelp social network service. Our results show that, geo-located metrics perform as well as rating or social metrics for selecting like-minded users and, thus, to issue a recommendation.Sociedad Argentina de Informática e Investigación Operativ

    On the Role of Personality Traits in Followee Recommendation Algorithms

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    Followee recommendation is a problem rapidly gaining importance in Twitter and other micro-blogging communities. Most traditional recommendation systems only rely on content or topology, disregarding the effect of psychological characteristics over the followee selection process. As personality is considered one of the primary factors that influence human behaviour, this study aims at assessing the impact of personality in the accurate prediction of followees. It analyses whether user personality could condition followee selection by combining personality traits with the most common followee recommendation factors.Sociedad Argentina de Informática e Investigación Operativa (SADIO

    On the Role of Personality Traits in Followee Recommendation Algorithms

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    Followee recommendation is a problem rapidly gaining importance in Twitter and other micro-blogging communities. Most traditional recommendation systems only rely on content or topology, disregarding the effect of psychological characteristics over the followee selection process. As personality is considered one of the primary factors that influence human behaviour, this study aims at assessing the impact of personality in the accurate prediction of followees. It analyses whether user personality could condition followee selection by combining personality traits with the most common followee recommendation factors.Sociedad Argentina de Informática e Investigación Operativa (SADIO

    An analysis on the impact of geolocation in recommending venues in location-based social networks

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    The pervasiveness of geo-located devices has opened new possibilities in recommender systems on social networks. In effect, Location-Based Social Networks or LBSNs are a relatively new breed of social networks that let users share their location by triggering ”check-in” events on venues, such as businesses or historical places. In this paper, we compare the performance of traditional rating and social-based similarity metrics against location-based metrics in a userbased collaborative filtering algorithm that recommends venues or places to visit. This analysis was performed on a large real-world dataset provided by the Yelp social network service. Our results show that, geo-located metrics perform as well as rating or social metrics for selecting like-minded users and, thus, to issue a recommendation.Sociedad Argentina de Informática e Investigación Operativ

    An analysis on the impact of geolocation in recommending venues in location-based social networks

    Get PDF
    The pervasiveness of geo-located devices has opened new possibilities in recommender systems on social networks. In effect, Location-Based Social Networks or LBSNs are a relatively new breed of social networks that let users share their location by triggering ”check-in” events on venues, such as businesses or historical places. In this paper, we compare the performance of traditional rating and social-based similarity metrics against location-based metrics in a userbased collaborative filtering algorithm that recommends venues or places to visit. This analysis was performed on a large real-world dataset provided by the Yelp social network service. Our results show that, geo-located metrics perform as well as rating or social metrics for selecting like-minded users and, thus, to issue a recommendation.Sociedad Argentina de Informática e Investigación Operativ

    DPM: A novel distributed large-scale social graph processing framework for link prediction algorithms

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    Large-scale graphs have become ubiquitous in social media. Computer-based recommendations in these huge graphs pose challenges in terms of algorithm design and resource usage efficiency when processing recommendations in distributed computing environments. Moreover, recommendation algorithms for graphs, particularly link prediction algorithms, have different requirements depending of the way the underlying graph is traversed. Path-based algorithms usually perform traversals in different directions to build a large ranking of vertices to recommend, whereas random walk-based algorithms build an initial subgraph and perform several iterations on those vertices to compute the final ranking. In this work, we propose a distributed graph processing framework called Distributed Partitioned Merge (DPM), which supports both types of algorithms and we compare its performance and resource usage w.r.t. two relevant frameworks, namely Fork-Join and Pregel. In our experiments, we show that in most tests DPM outperforms both Pregel and Fork-Join in terms of recommendation time, with a minor penalization in network usage in some scenarios.Fil: Corbellini, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Instituto Superior de Ingeniería del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de Ingeniería del Software; ArgentinaFil: Godoy, Daniela Lis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Instituto Superior de Ingeniería del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de Ingeniería del Software; ArgentinaFil: Mateos Diaz, Cristian Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Instituto Superior de Ingeniería del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de Ingeniería del Software; ArgentinaFil: Schiaffino, Silvia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Instituto Superior de Ingeniería del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de Ingeniería del Software; ArgentinaFil: Zunino Suarez, Alejandro Octavio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Instituto Superior de Ingeniería del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de Ingeniería del Software; Argentin

    On the Role of Personality Traits in Followee Recommendation Algorithms

    Get PDF
    Followee recommendation is a problem rapidly gaining importance in Twitter and other micro-blogging communities. Most traditional recommendation systems only rely on content or topology, disregarding the effect of psychological characteristics over the followee selection process. As personality is considered one of the primary factors that influence human behaviour, this study aims at assessing the impact of personality in the accurate prediction of followees. It analyses whether user personality could condition followee selection by combining personality traits with the most common followee recommendation factors.Sociedad Argentina de Informática e Investigación Operativa (SADIO

    Análise epidemiológica de carcaças bovinas afetadas por cisticercose e hidatidose no estado do Rio Grande do Sul de 2014 a 2018

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    Bovine cysticercosis and hydatidosis are frequently identified by inspectors in slaughterhouses from the state of Rio Grande do Sul. Slaughterhouse records can provide valuable information for animal-related diseases and public health surveillance. Analyzing these data can aid set priorities to regions or properties that need more attention. Slaughter condemnation data is collected daily and stored in the Agricultural Defense System (SDA) database of the State Veterinary Services. However, it needs to be turned into useful information in bovine cysticercosis and hydatidosis surveillance programs. This study aimed to discuss how the analysis of condemnation data in the context of epidemiology can be useful for a surveillance system of bovine cysticercosis and hydatidosis. For this purpose, slaughter data of 5,137,870 cattle from 480,000 animal movement permits (GTA) from 97,891 farms from 2014 to 2018 were obtained from the Secretary of Agriculture, Livestock and Rural Development of the State of Rio Grande do Sul (SEAPDR-RS). Differences in the occurrence rates of bovine cysticercosis and hydatidosis among mesoregions over time were assessed through generalized linear models. Cysticercosis was identified in 65,379 (1.27%) carcasses and hydatidosis in 323,395 (6.29%). The occurrence rates of both diseases varied distinctly over time between the regions (p<0.01). Next, a process was developed to identify priority farms to target a surveillance program based on the prevalence. Period prevalence for cysticercosis and hydatidosis was obtained for each farm. The epidemiological indicator was calculated for each farm, dividing the number of affected carcasses by the number of bovines sent to slaughter during the period. The mean prevalence was obtained, and the exact binomial test was applied to identify farms presenting prevalence above the mean. It was observed that 2.48% and 6.17% of the farms had prevalence above the population mean prevalence of cysticercosis and hydatidosis, respectively. The Western mesoregion had the highest percentage of farms with prevalence above the average for cysticercosis (6.9%), followed by the Southwest mesoregion (6.0%). For hydatidosis, the percentage frequency of farms with prevalence above the average was markedly higher in the mesoregions Southeast (32.8%) and Southwest (29.5%). The results showed that analysis of slaughterhouse condemnation data of SDA is useful to identify situations in which the occurrence of the diseases is significantly higher than the average to apply additional measures or epidemiological investigations. This information may be useful in plans of epidemiological surveillance programs for controlling bovine cysticercosis and hydatidosis by the State’s Official Veterinary Services.Lesões características de cisticercose e hidatidose bovina são frequentemente identificadas por fiscais em abatedouros no Rio Grande do Sul. Dados de condenações destas propriedades são coletados diariamente e armazenados em banco de dados do Sistema de Defesa Agropecuária (SDA) da Secretaria Estadual de Agricultura, Pecuária e Desenvolvimento Rural (SEAPDR-RS), podendo fornecer informações valiosas para a vigilância de doenças de importância para a saúde animal e saúde pública, bem como, contribuir para a tomada de decisão direcionada a propriedades rurais ou regiões que realmente necessitam de intervenção sanitária. No entanto, estes dados precisam ser transformados em informação útil para programas de prevenção e controle da cisticercose e da hidatidose bovina. O presente trabalho teve como objetivo analisar os dados de condenações de carcaças bovinas abatidas em frigoríficos sob inspeção estadual no Rio Grande do Sul, no período de 2014 a 2018. Foram utilizados dados de 5.137.870 bovinos enviados para abate em 480.000 lotes (GTA emitidas) de 97.891 fazendas. Diferenças nas taxas de ocorrência de cisticercose e hidatidose bovina ao longo do tempo, entre as mesorregiões do Rio Grande do Sul, foram analisadas por meio de modelos lineares generalizados. A cisticercose foi identificada em 65.379 (1,27%) carcaças e a hidatidose em 323.395 (6,29%) carcaças. Ao longo do tempo detectou-se uma tendência de redução nas taxas de ocorrência das duas doenças que, por sua vez, se comportaram de maneira distinta entre as mesorregiões (p<0,01). Por outro lado, desenvolveu-se um processo para identificação de propriedades prioritárias para ação de vigilância com base na prevalência. A prevalência no período para cisticercose e hidatidose foi calculada para cada propriedade. O indicador foi obtido dividindo-se o número de carcaças afetadas pelo número total de animais enviados para abate, ou seja, é a proporção de ocorrência das parasitoses dentre os animais enviados para abate em cada propriedade no período de cinco anos. A prevalência média ou populacional (π), que é a média das prevalências de todas as propriedades, foi calculada e, em seguida, foi aplicado o teste exato binomial para identificar as propriedades com prevalência acima da média para ambas as doenças. Foi observado que 2,48% (2.425/97.841) e 6,17% (6.039/97.841) das propriedades apresentavam prevalências acima da média populacional para cisticercose e hidatidose, respectivamente. Observou-se que a mesorregião Centro Ocidental possui maior frequência percentual de propriedades com prevalência de cisticercose acima da média (6,9%), seguido pela mesorregião Sudoeste (6,0%). Já para hidatidose, a frequência percentual de propriedades com prevalência acima da média foi substancialmente superior nas mesorregiões Sudeste (32,8%) e Sudoeste (29,5%) quando comparada às demais. Os resultados demonstraram que com os dados de condenações de abatedouro do SDA foi possível identificar situações em que a ocorrência das doenças é significativamente alta e que necessitam de medidas ou investigações epidemiológicas adicionais. O conhecimento dessa informação pode ser útil no planejamento de programas de vigilância epidemiológica para o controle da cisticercose e hidatidose bovina pelos serviços veterinários oficiais do Estado

    Presentation of the Psycho-Cardiological Schedule and convergence levels analyses among the psycho-cardiological screening and the psychological assessment

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    In Cardiovascular Rehabilitation the increasing inpatients complexity suggests the necessity to develop screening methods which allow to identify those patients that require a psychological intervention. Material and methods: A Psycho-Cardiological Schedule (PCS) was developed with the aim of detecting the critical situation indicators or the presence of psychological, social and cognitive problems. The PCS, compiled by a nurse or cardiologist in collaboration with a psychologist, allows to assess the need for a deeper psychological examination, clinical and/or with tests. Aim of the present study is to identify the convergence levels among the observational and anamnestic data of the PCS collected by a nurse and the clinical and/or test data of the psychological deeper assessment. Results: Among the 87 patients recruited in January- February 2010, 28 (aged 53.5±12.6, M=20, F=8) fulfilled the criteria for a deeper psychological examination: age <50, manifestation of psychological/behavioural problems, neuropsychological disorders, low adherence to prescriptions, inadequate disease knowledge/representation. From data comparisons emerged convergence levels with 100% concordance as to smoke habits and problems in social-family support. High convergence levels also resulted as to emotional and/or behavioural problems (92.8%) and inadequate adherence to prescriptions (89.3%). Lower levels of concordance (82.1%) emerged when considering disease knowledge/ representation, issues specifically linked to cognition and subjective illness experience, not directly detectable from behaviour. Conclusions: our data confirm the synergic efficacy of the two evaluations: the Psycho-Cardiological Schedule reliably identifies the problematic macro-categories, mainly if they are characterized by behavioural indicators, which facilitate the detection. The psychological approach appears more suitable for better specifing macro-categories characteristics and for detecting critical aspects not overt but not less important, providing therefore advice for a therapeutic psychological management

    Soroprevalência da infecção por pythium insidiosum em equinos no estado do Rio Grande do Sul

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    An epidemiological survey was carried out by performing an Enzyme Linked Immuno Sorbent Assay (ELISA) test to determine the seroprevalence of Pythium insidiosum infection in equine in Rio Grande do Sul State (RS), Brazil. The serological study covered seven geographical regions of RS, classified according to the Instituto Brasileiro de Geografia e Estatística (IBGE). The samples were obtained from official veterinary service (Serviço Veterinário Oficial, SVO) linked to the Secretaria da Agricultura, Pecuária e Agronegócio of RS (SEAPA-RS) to proceed the investigation of equine infectious anemia in 2014. Samples were collected during the months of September and October of 2013, covering the seven geographical regions of RS, and totalized 1,002 serum samples. The seroprevalence for P. insidiosum in RS was 11.1% (CI95% 9.23 to 13.22). The relative risk (RR) of the presence of antibodies anti-P. insidiosum was in the regions Southeast 11.17 (CI95%, 4.65 to 26.8), Porto Alegre 4.62 (CI95%, 1.70 to 12.55), Southwest 11.17 (CI95%, 4.65 to 26.8) and Northwestern 3.72 (CI95%, 1.52 to 9.09). The highest prevalence (69.1%) was observed in females with RR of 1.59 (CI95%, 1.11 to 2.27). When the presence of dams was evaluated, the seropositivity was evident in 74.4%, presenting an association of 2.13 (CI95%, 1.16 to 3.91) compared to farms without dams. In properties with veterinary assistance, the frequency of 72.7% and RR of 3.04 (CI95%,, 1,85 to 4,98) of seropositivity were observed. Due to the importance of pythiosis in horse herds, this study highlights the presence of anti-P. insidiosum antibodies in horses in RS, Brazil.Um levantamento soroepidemiológico foi realizado através do teste de ELISA indireto para determinar a soroprevalência da infecção por Pythium insidiosum em equinos no estado do Rio Grande do Sul (RS), classificadas de acordo com o Instituto Brasileiro de Geografia e Estatística (IBGE). As amostras utilizadas eram provenientes do cadastro das propriedades do Serviço Veterinário Oficial (SVO), da Secretaria da Agricultura, Pecuária e Agronegócio do RS (SEAPA-RS), coletadas para o inquérito da anemia infecciosa equina de 2014. As coletas foram realizadas durante os meses de setembro e outubro de 2013, abrangendo as sete mesorregiões geográficas do RS, e totalizaram 1.002 amostras de soro. Do total das amostras testadas, 11.1% (CI95% 9.23 to 13.22) foram soropositivas para P. insidiosum. Constatou-se o risco relativo (RR) da presença de anticorpos anti-P. insidiosum nas regiões Sudeste 11,17(IC95%, 4,65- 26,8), Porto Alegre 4,62 (IC95%, 1,70-12,55), Sudoeste 11,17 (IC95%, 4,65-26,8) e Noroeste 3,72 (IC95%, 1,52-9,09). Observou-se a maior soroprevalência (69,1%) em fêmeas com RR de 1,59 (IC95%, 1,11- 2,27). Quanto à presença de açudes, evidenciou-se soropositividade em 74,4% das propriedades, apresentando associação de 2,13 (IC95%,1,16-3,91) em comparação com propriedades sem açude. Em propriedades com assistência veterinária, foi verificada a frequência de 72,7% e RR de 3,04 (IC95%,1,85-4,98). Diante da relevância da pitiose em rebanhos equinos, destaca-se a presença de anticorpos anti-P. insidiosum em equinos no estado do RS
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