Hierarchical classification in text mining for sentiment analysis of online news

Sentiment analysis in text mining is a challenging task. Sentiment is subtly reflected by the tone and affective content of a writer’s words. Conventional text mining techniques, which are based on keyword frequencies, usually run short of accurately detecting such subjective information implied in the text. In this paper, we evaluate several popular classification algorithms, along with three filtering schemes. The filtering schemes progressively shrink the original dataset with respect to the contextual polarity and frequent terms of a document. We call this approach “hierarchical classification”. The effects of the approach in different combination of classification algorithms and filtering schemes are discussed over three sets of controversial online news articles where binary and multi-class classifications are applied. Meanwhile we use two methods to test this hierarchical classification model, and also have a comparison of the two methods.     

Experimental study of stable surfaces for anti-slug control in multi-phase flow

Severe slugging flow is always challenging in oil & gas production, especially for the current offshore based production. The slugging flow can cause a lot of problems, such as those relevant to production safety, fatigue as well as capability. As one typical phenomenon in multi-phase flow dynamics, the slug can be avoided or eliminated by proper facility design or control of operational conditions. Based on a testing facility which can emulate a pipeline-riser or a gas-lifted production well in a scaled-down manner, this paper experimentally studies the correlations of key operational parameters with severe slugging flows. These correlations are reflected through an obtained stable surface in the parameter space, which is a natural extension of the bifurcation plot. The maximal production opportunity without compromising the stability is also studied. Relevant studies have already showed that the capability, performance and efficiency of anti-slug control can be dramatically improved if these stable surfaces can be experimentally determined beforehand. The paper concludes that obtaining the stable surface on the new developed map can significantly improve the production rate in a control scheme. Even though the production rate can be further improved by moving the stable surface using advanced control strategies, the constant inputs can in some cases be preferable due to the easier implementation.     

Physically Meaningful Rendering using Tristimulus Colours

In photorealistic image synthesis the radiative transfer equation is often not solved by simulating every wavelength of light, but instead by computing tristimulus transport, for instance using sRGB primaries as a basis. This choice is convenient, because input texture data is usually stored in RGB colour spaces. However, there are problems with this approach which are often overlooked or ignored. By comparing to spectral reference renderings, we show how rendering in tristimulus colour spaces introduces colour shifts in indirect light, violation of energy conservation, and unexpected behaviour in participating media. Furthermore, we introduce a fast method to compute spectra from almost any given XYZ input colour. It creates spectra that match the input colour precisely. Additionally, like in natural reflectance spectra, their energy is smoothly distributed over wide wavelength bands. This method is both useful to upsample RGB input data when spectral transport is used and as an intermediate step for corrected tristimulus‐based transport. Finally, we show how energy conservation can be enforced in RGB by mapping colours to valid reflectances.     

The use and acceptance of new media entertainment technology by elderly users: development of an expanded technology acceptance model

Research on elderly people's ICT acceptance and use often relies on the technology acceptance model (TAM) framework, but has been mostly limited to task-oriented uses. This article expands approaches in technology acceptance and use by developing a model to explain entertainment-related uses of new media technology by elderly people. On a theoretical level, we expand the TAM perspective by adding concepts that act as barriers and/or facilitators of technology acceptance, namely technophobia, self-efficacy and previous experience and expertise with technology. We develop an expanded TAM by testing the role of these concepts in two studies on entertainment media technology. In Study 1, we investigate behavioural intention to use 3D cinema among N?=?125 German elderly media users (Age 50+). In Study 2, we focus the actual use of a computer game simulation by N?=?115 German and US elderly media users (Age 50+). Findings in both studies point towards the central role of perceived usefulness, here modelled as enjoyment, as the reason for elderly people's use and acceptance of entertainment media technology. Perceived ease of use is seen as a precondition for enjoyment, particularly for interactive media.     

Future Proof: The Transition to Digital at IFI Archive

Informed by research over the past two years and the work of colleagues in peer institutions, the IFI Irish Film Archive developed a six-year Digital Preservation and Access strategy which launched in 2014. Fundamental to this Strategy was the design and installation of digital archive tools for long term preservation and the redesign of workflow practices to facilitate accession and management of high resolution digital film and broadcast assets and associated metadata. This article outlines the steps taken and standards applied in developing a future proof digital audiovisual archive.     

The structure and content of programming knowledge: Disentangling training and language effects in theories of skill development

This article reviews the extensive literature emerging from studies concerned with skill acquisition and the development of knowledge representation in programming. In particular, it focuses upon theories of program comprehension that suggest programming knowledge can be described in terms of stereotypical knowledge structures that can in some way capture programming expertise independently of the programming language used and in isolation from a programmer's specific training experience. An attempt is made to demonstrate why existing views are inappropriate. On the one hand, programs are represented in terms of a variety of formal notations ranging from the quasi‐mathematical to the near textual. It is argued that different languages may lead to different forms of knowledge representation, perhaps emphasizing certain structures at the expense of others or facilitating particular strategies. On the other hand, programmers are typically taught problem‐solving techniques that suggest a strict approach to problem decomposition. Hence, it seems likely that another factor that may mediate the development of knowledge representation, and that has not received significant attention elsewhere, is related to the training experience that programmers typically encounter. In this article, recent empirical studies that have addressed these issues are reviewed, and the implications of these studies for theories of skill acquisition and for knowledge representation are discussed. In conclusion, a more extensive account of knowledge representation in programming is presented that emphasizes training effects and the role played by specific language features in the development of knowledge representation within the programming domain.     

Twenty years of artificial life art

This essay begins with discussion of four relatively recent works which are representative of major themes and preoccupations in Artificial Life Art: ‘Propagaciones’ by Leo Nuñez; ‘Sniff’ by Karolina Sobecka and Jim George; ‘Universal Whistling Machine’ by Marc Boehlen; and ‘Performative Ecologies’ by Ruari Glynn. This essay is an attempt to contextualise these works by providing an overview of the history and forms of Artificial Life Art as it has developed over two decades, along with some background in the ideas of the Artificial Life movement of the late 1980s and 1990s.1 A more extensive study of the theoretical history of Artificial Life can be found in my paper ‘Artificial Life Art—A Primer’, in the Proceedings of DAC09 and also at http://www.ace.uci.edu/Penny. Excerpts from that essay are included here.      

Using space windowing for a preliminary analysis of complex time data in human component system studies. Examples with eye-tracking in advertising and car/head movements in driving

Empirical studies of human systems often involve recording multidimensional signals because the system components may require physical measurements (e.g., temperature, pressure, body movements and/or movements in the environment) and physiological measurements (e.g., electromyography or electrocardiography). Analysis of such data becomes complex if both the multifactor aspect and the multivariate aspect are retained. Three examples are used to illustrate the role of fuzzy space windowing and the large number of data analysis paths. The first example is a classic simulated data set found in the literature, which we use to compare several data analysis paths generated with principal component analysis and multiple correspondence analysis with crisp and fuzzy windowing. The second example involves eye-tracking data based on advertising, with a focus on the case of one category variable, but with the possibility of several space windowing models and time entities. The third example concerns car and head movement data from a driving vigilance study, with a focus on the case involving several quantitative variables. The notions of analysis path multiplicity and information are discussed both from a general perspective and in terms of our two real examples.     

Combining the triangle method with thermal inertia to estimate regional evapotranspiration — Applied to MSG-SEVIRI data in the Senegal River basin

Spatially distributed estimates of evaporative fraction and actual evapotranspiration are pursued using a simple remote sensing technique based on a remotely sensed vegetation index (NDVI) and diurnal changes in land surface temperature. The technique, known as the triangle method, is improved by utilizing the high temporal resolution of the geostationary MSG-SEVIRI sensor. With 15 min acquisition intervals, the MSG-SEVIRI data allow for a precise estimation of the morning rise in land surface temperature which is a strong proxy for total daytime sensible heat fluxes. Combining the diurnal change in surface temperature, dT_s with an interpretation of the triangular shaped dT_s − NDVI space allows for a direct estimation of evaporative fraction. The mean daytime energy available for evapotranspiration (R_n − G) is estimated using several remote sensors and limited ancillary data. Finally regional estimates of actual evapotranspiration are made by combining evaporative fraction and available energy estimates. The estimated evaporative fraction (EF) and actual evapotranspiration (ET) for the Senegal River basin have been validated against field observations for the rainy season 2005. The validation results showed low biases and RMSE and R² of 0.13 [−] and 0.63 for EF and RMSE of 41.45 W m^− 2 and R² of 0.66 for ET.