918 resultados para Spatial analysis statistics -- Data processing
Resumo:
This study examines the efficiency of search engine advertising strategies employed by firms. The research setting is the online retailing industry, which is characterized by extensive use of Web technologies and high competition for market share and profitability. For Internet retailers, search engines are increasingly serving as an information gateway for many decision-making tasks. In particular, Search engine advertising (SEA) has opened a new marketing channel for retailers to attract new customers and improve their performance. In addition to natural (organic) search marketing strategies, search engine advertisers compete for top advertisement slots provided by search brokers such as Google and Yahoo! through keyword auctions. The rationale being that greater visibility on a search engine during a keyword search will capture customers' interest in a business and its product or service offerings. Search engines account for most online activities today. Compared with the slow growth of traditional marketing channels, online search volumes continue to grow at a steady rate. According to the Search Engine Marketing Professional Organization, spending on search engine marketing by North American firms in 2008 was estimated at $13.5 billion. Despite the significant role SEA plays in Web retailing, scholarly research on the topic is limited. Prior studies in SEA have focused on search engine auction mechanism design. In contrast, research on the business value of SEA has been limited by the lack of empirical data on search advertising practices. Recent advances in search and retail technologies have created datarich environments that enable new research opportunities at the interface of marketing and information technology. This research uses extensive data from Web retailing and Google-based search advertising and evaluates Web retailers' use of resources, search advertising techniques, and other relevant factors that contribute to business performance across different metrics. The methods used include Data Envelopment Analysis (DEA), data mining, and multivariate statistics. This research contributes to empirical research by analyzing several Web retail firms in different industry sectors and product categories. One of the key findings is that the dynamics of sponsored search advertising vary between multi-channel and Web-only retailers. While the key performance metrics for multi-channel retailers include measures such as online sales, conversion rate (CR), c1ick-through-rate (CTR), and impressions, the key performance metrics for Web-only retailers focus on organic and sponsored ad ranks. These results provide a useful contribution to our organizational level understanding of search engine advertising strategies, both for multi-channel and Web-only retailers. These results also contribute to current knowledge in technology-driven marketing strategies and provide managers with a better understanding of sponsored search advertising and its impact on various performance metrics in Web retailing.
Resumo:
Memory is a multi-component cognitive ability to retain and retrieve information presented in different modalities. Research on memory development has shown that the memory capacity and the processes improve gradually from early childhood to adolescence. Findings related to the sex-differences in memory abilities in early childhood have been inconsistent. Although previous research has demonstrated the effects of the modality of stimulus presentation (auditory versus verbal) and the type of material to be remembered (visual/spatial versus auditory/verbal) on the memory processes and memory organization, the recent research with children is rather limited. The present study is a secondary analysis of data, originally collected from 530 typically developing Turkish children and adolescents. The purpose of the present study was to examine the age-related developments and sex differences in auditory-verbal and visual-spatial short-term memory (STM) in 177 typically developing male and female children, 5 to 8 years of age. Dot-Locations and Word-Lists from the Children's Memory Scale were used to measure visual-spatial and auditory-verbal STM performances, respectively. The findings of the present study suggest age-related differences in both visual-spatial and auditory-verbal STM. Sex-differences were observed only in one visual-spatial STM subtest performance. Modality comparisons revealed age- and task-related differences between auditory-verbal and visual-spatial STM performances. There were no sex-related effects in terms of modality specific performances. Overall, the results of this study provide evidence of STM development in early childhood, and these effects were mostly independent of sex and the modality of the task.
Resumo:
Affiliation: Pascal Michel : Département de pathologie et microbiologie, Faculté de médecine vétérinaire
Resumo:
Le béluga du Saint-Laurent est une espèce menacée au Canada et protégée par la Loi sur les espèces en péril du Canada. La détermination des fonctions biologiques de ses habitats essentiels est nécessaire afin d’assurer le rétablissement de la population. Parcs Canada a entamé en 2009 un suivi des proies du béluga dans deux de ses aires de fréquentation intensive situées dans le Parc marin du Saguenay–Saint-Laurent : l’embouchure de la rivière Saguenay et la baie Sainte-Marguerite. L’étude de l’abondance et de la distribution des proies est réalisée par sondage hydroacoustique le long de transects à l’aide d’un échosondeur multifréquences. Un protocole d’observations systématiques du béluga est mené simultanément aux sondages hydroacoustiques à partir de sites terrestres. Le premier objectif de cette étude est de développer la méthodologie concernant le traitement, la classification et la cartographie des données hydroacoustiques échantillonnées. L’objectif principal consiste à déterminer si l’abondance et la distribution des proies pélagiques ont une influence sur l’utilisation de ces deux habitats par le béluga. La cartographie de la biomasse relative de poissons a été réalisée pour la couche de surface, la couche en profondeur et pour l’ensemble de la colonne d’eau par krigeage ordinaire pour les deux habitats pour les 29 transects. À la baie Sainte-Marguerite, le nombre de bélugas observés augmente avec la biomasse relative des proies en surface et en profondeur. À l’embouchure de la rivière Saguenay, les résultats n’ont pas été concluants. Les résultats suggèrent que l’alimentation pourrait être l’une des fonctions biologiques de la baie Sainte-Marguerite.
Resumo:
This paper describes a method for analyzing scoliosis trunk deformities using Independent Component Analysis (ICA). Our hypothesis is that ICA can capture the scoliosis deformities visible on the trunk. Unlike Principal Component Analysis (PCA), ICA gives local shape variation and assumes that the data distribution is not normal. 3D torso images of 56 subjects including 28 patients with adolescent idiopathic scoliosis and 28 healthy subjects are analyzed using ICA. First, we remark that the independent components capture the local scoliosis deformities as the shoulder variation, the scapula asymmetry and the waist deformation. Second, we note that the different scoliosis curve types are characterized by different combinations of specific independent components.
Resumo:
The development of conceptual knowledge systems specifically requests knowledge acquisition tools within the framework of formal concept analysis. In this paper, the existing tools are presented, and furhter developments are discussed.
Resumo:
While most data analysis and decision support tools use numerical aspects of the data, Conceptual Information Systems focus on their conceptual structure. This paper discusses how both approaches can be combined.
Resumo:
Conceptual Graphs and Formal Concept Analysis have in common basic concerns: the focus on conceptual structures, the use of diagrams for supporting communication, the orientation by Peirce's Pragmatism, and the aim of representing and processing knowledge. These concerns open rich possibilities of interplay and integration. We discuss the philosophical foundations of both disciplines, and analyze their specific qualities. Based on this analysis, we discuss some possible approaches of interplay and integration.
Resumo:
Association rules are used to investigate large databases. The analyst is usually confronted with large lists of such rules and has to find the most relevant ones for his purpose. Based on results about knowledge representation within the theoretical framework of Formal Concept Analysis, we present relatively small bases for association rules from which all rules can be deduced. We also provide algorithms for their calculation.
Resumo:
Semantic Web Mining aims at combining the two fast-developing research areas Semantic Web and Web Mining. This survey analyzes the convergence of trends from both areas: Growing numbers of researchers work on improving the results of Web Mining by exploiting semantic structures in the Web, and they use Web Mining techniques for building the Semantic Web. Last but not least, these techniques can be used for mining the Semantic Web itself. The second aim of this paper is to use these concepts to circumscribe what Web space is, what it represents and how it can be represented and analyzed. This is used to sketch the role that Semantic Web Mining and the software agents and human agents involved in it can play in the evolution of Web space.
Resumo:
About ten years ago, triadic contexts were presented by Lehmann and Wille as an extension of Formal Concept Analysis. However, they have rarely been used up to now, which may be due to the rather complex structure of the resulting diagrams. In this paper, we go one step back and discuss how traditional line diagrams of standard (dyadic) concept lattices can be used for exploring and navigating triadic data. Our approach is inspired by the slice & dice paradigm of On-Line-Analytical Processing (OLAP). We recall the basic ideas of OLAP, and show how they may be transferred to triadic contexts. For modeling the navigation patterns a user might follow, we use the formalisms of finite state machines. In order to present the benefits of our model, we show how it can be used for navigating the IT Baseline Protection Manual of the German Federal Office for Information Security.
Resumo:
Ontologies have been established for knowledge sharing and are widely used as a means for conceptually structuring domains of interest. With the growing usage of ontologies, the problem of overlapping knowledge in a common domain becomes critical. In this short paper, we address two methods for merging ontologies based on Formal Concept Analysis: FCA-Merge and ONTEX. --- FCA-Merge is a method for merging ontologies following a bottom-up approach which offers a structural description of the merging process. The method is guided by application-specific instances of the given source ontologies. We apply techniques from natural language processing and formal concept analysis to derive a lattice of concepts as a structural result of FCA-Merge. The generated result is then explored and transformed into the merged ontology with human interaction. --- ONTEX is a method for systematically structuring the top-down level of ontologies. It is based on an interactive, top-down- knowledge acquisition process, which assures that the knowledge engineer considers all possible cases while avoiding redundant acquisition. The method is suited especially for creating/merging the top part(s) of the ontologies, where high accuracy is required, and for supporting the merging of two (or more) ontologies on that level.