Search results for "INDEX"
showing 10 items of 5395 documents
Marginal contribution, reciprocity and equity in segregated groups: Bounded rationality and selforganization in social networks
2007
We study the formation of social networks that are based on local interaction and simple rule following. Agents evaluate the profitability of link formation on the basis of the Myerson-Shapley principle that payoffs come from the marginal contribution they make to coalitions. The NP-hard problem associated with the Myerson-Shapley value is replaced by a boundedly rational 'spatially' myopic process. Agents consider payoffs from direct links with their neighbours (level 1), which can include indirect payoffs from neighbours' neighbours (level 2) and up to M-levels that are far from global. Agents dynamically break away from the neighbour to whom they make the least marginal contribution. Com…
Mapping Economic Activity in the European Union: Do Ownership, Industry and Location Matter?
2020
The paper proposes a new method for analysing the structure and dynamics of economic activity undertaken by locally owned and foreign-owned companies within the European Union. We employ an unsupervised learning algorithm that generates a neural network depicted on Kohonen maps and offering a clustering of companies with a different ownership (local and foreign) from various industries and countries of the European Union during 2009–2016. The research methodology, based on a self-organizing map (SOM) algorithm, belongs to a class of neural networks trained to organize data so that unknown patterns may be discovered, thus leading to results that cannot be attained by more traditional cluster…
Positionless aspect based sentiment analysis using attention mechanism.
2021
Abstract Aspect-based sentiment analysis (ABSA) aims at identifying fine-grained polarity of opinion associated with a given aspect word. Several existing articles demonstrated promising ABSA accuracy using positional embedding to show the relationship between an aspect word and its context. In most cases, the positional embedding depends on the distance between the aspect word and the remaining words in the context, known as the position index sequence. However, these techniques usually employ both complex preprocessing approaches with additional trainable positional embedding and complex architectures to obtain the state-of-the-art performance. In this paper, we simplify preprocessing by …
Lightweight BWT Construction for Very Large String Collections
2011
A modern DNA sequencing machine can generate a billion or more sequence fragments in a matter of days. The many uses of the BWT in compression and indexing are well known, but the computational demands of creating the BWT of datasets this large have prevented its applications from being widely explored in this context. We address this obstacle by presenting two algorithms capable of computing the BWT of very large string collections. The algorithms are lightweight in that the first needs O(m log m) bits of memory to process m strings and the memory requirements of the second are constant with respect to m. We evaluate our algorithms on collections of up to 1 billion strings and compare thei…
Lightweight algorithms for constructing and inverting the BWT of string collections
2013
Recent progress in the field of \{DNA\} sequencing motivates us to consider the problem of computing the Burrows‚ÄìWheeler transform (BWT) of a collection of strings. A human genome sequencing experiment might yield a billion or more sequences, each 100 characters in length. Such a dataset can now be generated in just a few days on a single sequencing machine. Many algorithms and data structures for compression and indexing of text have the \{BWT\} at their heart, and it would be of great interest to explore their applications to sequence collections such as these. However, computing the \{BWT\} for 100 billion characters or more of data remains a computational challenge. In this work we ad…
Changes in land surface temperatures and NDVI values over Europe between 1982 and 1999
2006
Abstract We used land surface temperature (LST) algorithms and NDVI values to estimate changes in vegetation in the European continent between 1982 and 1999 from the Pathfinder AVHRR Land (PAL) dataset. These two parameters are monitored through HANTS (Harmonic ANalysis of Time Series) software, which allows the simultaneous observation of mean value, first harmonic amplitude and phase behaviors in the same image. These results for each complete year of data show the effect of volcanic aerosols and orbital drift on PAL data. Comparison of time series of HANTS cloud-free time series with the original time series for various land cover proves that this software is useful for LST analysis, alt…
Comparative statistical studies on the anthropology of the Iron Age (last millennium B.C.)
1975
Abstract Extending previous statistical studies on the anthropology of the Neolithic and Bronze Ages, anthropological material from the Iron Age (1000-0) was compiled and condensed into 71 series (population samples). Penrose distances were calculated on the basis of 10 skull measurements. The dendrogram consisting of 49 larger series shows a division into a west- and an east-cluster. The west-cluster can be broken down into a northern, entirely European section, and into a southern subcluster, stretching from Sardinia to Pakistan. The east-cluster differs from the west-cluster above all in the larger width measurements, as in the case with the north-east and south-west complexes in the Neo…
Serotypes of Aggregatibacter actinomycetemcomitans in relation to periodontal status and geographic origin of individuals-a review of the literature
2014
Objectives: Several studies have focused on the relationship among serotype distribution, ethnical status and geo - graphic populations, and periodontal conditions. Studies that have investigated the prevalence and the distribution of A. actinomycetemcomitans serotypes and the relation between the different serotypes of the bacterium and periodontal status were reviewed. Material and Methods: A systematic literature search for publications regarding the distribution of A. actinomyc - etemcomitans serotypes in subgingival samples of periodontitis patients and periodontally healthy subjects by employing polymerase chain reaction (PCR) was conducted. Results: From the 85 studies identified in …
Misure di agglomerazione spaziale nei Sistemi Locali del Lavoro siciliani
2009
Spatial agglomeration indicators in the Sicilian Local Labour Systems Objectives - This paper examines the links among productive specialization, variety of the economic environment and knowledge spillovers on the basis of the territorial analyses present in the current literature. With the aim of identifying localization benefits in a particular area, some aspects of business settling are compared with trends in the development of economic activities and, particularly, with agglomeration process of the firms. Methods and Results The empirical analysis will be carried out pointing to the dynamics of employment consequent to the effects of the externalities above mentioned. Employment data a…
Vertical integration and exclusivities in maritime freight transport
2011
A key recent theme in maritime freight transport is the involvement of shipping lines in terminal management. Such investments are costly but allow liners to provide better service. Most of these new terminals are dedicated terminals but some are non-exclusive and let rivals access them for a fee. In this paper, we show that a shipping line that builds its own terminal finds it strategically profitable (i) to continue routing part of its cargo through the open port facilities, and (ii) to keep its terminal non-exclusive. In this way, the liner investor pushes part of the rival's freight from the open to the new terminal. Besides, under non-exclusivities, the shipping lines offer a wider var…