923 resultados para Real Options Theory
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A large number of studies have been devoted to modeling the contents and interactions between users on Twitter. In this paper, we propose a method inspired from Social Role Theory (SRT), which assumes that a user behaves differently in different roles in the generation process of Twitter content. We consider the two most distinctive social roles on Twitter: originator and propagator, who respectively posts original messages and retweets or forwards the messages from others. In addition, we also consider role-specific social interactions, especially implicit interactions between users who share some common interests. All the above elements are integrated into a novel regularized topic model. We evaluate the proposed method on real Twitter data. The results show that our method is more effective than the existing ones which do not distinguish social roles. Copyright 2013 ACM.
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Purpose: To examine the use of real-time, generic edge detection, image processing techniques to enhance the television viewing of the visually impaired. Design: Prospective, clinical experimental study. Method: One hundred and two sequential visually impaired (average age 73.8 ± 14.8 years; 59% female) in a single center optimized a dynamic television image with respect to edge detection filter (Prewitt, Sobel, or the two combined), color (red, green, blue, or white), and intensity (one to 15 times) of the overlaid edges. They then rated the original television footage compared with a black-and-white image displaying the edges detected and the original television image with the detected edges overlaid in the chosen color and at the intensity selected. Footage of news, an advertisement, and the end of program credits were subjectively assessed in a random order. Results: A Prewitt filter was preferred (44%) compared with the Sobel filter (27%) or a combination of the two (28%). Green and white were equally popular for displaying the detected edges (32%), with blue (22%) and red (14%) less so. The average preferred edge intensity was 3.5 ± 1.7 times. The image-enhanced television was significantly preferred to the original (P < .001), which in turn was preferred to viewing the detected edges alone (P < .001) for each of the footage clips. Preference was not dependent on the condition causing visual impairment. Seventy percent were definitely willing to buy a set-top box that could achieve these effects for a reasonable price. Conclusions: Simple generic edge detection image enhancement options can be performed on television in real-time and significantly enhance the viewing of the visually impaired. © 2007 Elsevier Inc. All rights reserved.
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The extremely surface sensitive technique of metastable de-excitation spectroscopy (MDS) has been utilized to probe the bonding and reactivity of crotyl alcohol over Pd(111) and provide insight into the selective oxidation pathway to crotonaldehyde. Auger de-excitation (AD) of metastable He (23S) atoms reveals distinct features associated with the molecular orbitals of the adsorbed alcohol, corresponding to emission from the hydrocarbon skeleton, the O n nonbonding, and C═C π states. The O n and C═C π states of the alcohol are reversed when compared to those of the aldehyde. Density functional theory (DFT) calculations of the alcohol show that an adsorption mode with both C═C and O bonds aligned somewhat parallel to the surface is energetically favored at a substrate temperature below 200 K. Density of states calculations for such configurations are in excellent agreement with experimental MDS measurements. MDS revealed oxidative dehydrogenation of crotyl alcohol to crotonaldehyde between 200 and 250 K, resulting in small peak shifts to higher binding energy. Intramolecular changes lead to the opposite assignment of the first two MOs in the alcohol versus the aldehyde, in accordance with DFT and UPS studies of the free molecules. Subsequent crotonaldehyde decarbonylation and associated propylidyne formation above 260 K could also be identified by MDS and complementary theoretical calculations as the origin of deactivation and selectivity loss. Combining MDS and DFT in this way represents a novel approach to elucidating surface catalyzed reaction pathways associated with a “real-world” practical chemical transformation, namely the selective oxidation of alcohols to aldehydes.
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Although theory on team membership is emerging, limited empirical attention has been paid to the effects of different types of team membership on outcomes. We propose that an important but overlooked distinction is that between membership of real teams and membership of co-acting groups, with the former being characterized by members who report that their teams have shared objectives, and structural interdependence and engage in team reflexivity. We hypothesize that real team membership will be associated with more positive individual- and organizational-level outcomes. These predictions were tested in the English National Health Service, using data from 62,733 respondents from 147 acute hospitals. The results revealed that individuals reporting the characteristics of real team membership, in comparison with those reporting the characteristics of co-acting group membership, witnessed fewer errors and incidents, experienced fewer work related injuries and illness, were less likely to be victims of violence and harassment, and were less likely to intend to leave their current employment. At the organizational level, hospitals with higher proportions of staff reporting the characteristics of real team membership had lower levels of patient mortality and sickness absence. The results suggest the need to clearly delineate real team membership in order to advance scientific understanding of the processes and outcomes of organizational teamwork.
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This paper considers the problem of concept generalization in decision-making systems where such features of real-world databases as large size, incompleteness and inconsistence of the stored information are taken into account. The methods of the rough set theory (like lower and upper approximations, positive regions and reducts) are used for the solving of this problem. The new discretization algorithm of the continuous attributes is proposed. It essentially increases an overall performance of generalization algorithms and can be applied to processing of real value attributes in large data tables. Also the search algorithm of the significant attributes combined with a stage of discretization is developed. It allows avoiding splitting of continuous domains of insignificant attributes into intervals.
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Since the development of large scale power grid interconnections and power markets, research on available transfer capability (ATC) has attracted great attention. The challenges for accurate assessment of ATC originate from the numerous uncertainties in electricity generation, transmission, distribution and utilization sectors. Power system uncertainties can be mainly described as two types: randomness and fuzziness. However, the traditional transmission reliability margin (TRM) approach only considers randomness. Based on credibility theory, this paper firstly built models of generators, transmission lines and loads according to their features of both randomness and fuzziness. Then a random fuzzy simulation is applied, along with a novel method proposed for ATC assessment, in which both randomness and fuzziness are considered. The bootstrap method and multi-core parallel computing technique are introduced to enhance the processing speed. By implementing simulation for the IEEE-30-bus system and a real-life system located in Northwest China, the viability of the models and the proposed method is verified.
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2000 Mathematics Subject Classification: 94A12, 94A20, 30D20, 41A05.
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A műhelytanulmány két kutatási kérdést vizsgál. Egyrészt kiemelt szakirodalom alapján megvizsgálja, hogy az elméleti ajánlások milyen vezetési stílust és vezetői stílusjegyeket fogalmaznak meg követendőnek egy lean vállalat számára. Másrészt megvizsgálja, hogy a lean menedzsment gyakorlatának alkalmazásában fejlettebb vállalatok vezetői valóban az irodalom által javasolt, kívánatosnak tekintett vezetői stílusjegyeket tekintik-e pozitívnak. Vizsgálatunkat a Versenyképesség Kutató Központ 2009-es kérdőívének adatbázisán végeztük el, melyben mintegy 300 vállalat négy vezetőjének válaszai állnak rendelkezésre. A rendelkezésre álló mintából mi az 50 fő feletti foglalkoztatottal rendelkező, feldolgozóipari vállalatokra fókuszáltunk, esetükben elemeztük a vezérigazgató és a termelésvezető által követendőnek, jónak tartott vezetői stílusjegyek alkalmazását. ----- Abstract: The working paper focuses on two connected research quesions: Ono ne hand based on selected literature it systematically looks at the ideal leadership style and connected leader attributes that help in transforming a company into a real lean organization. On the other hand the paper analyzes whether leaders of companies with more developed lean practice do or do not follow these leadership related suggestions formulated in the literature. The study uses the fourth round of the Hungarian Competitiveness Research Survey from 2009. The survey has 300 valid observations. Four different respondents in each company filled in questionnaires, all of them were top managers (CEO, marketing /sales, finance, production). Plants were quite different alongside the most important organizational dimensions (volume, number of employee, industry, ownership). Previous researches pointed out that lean management is more likely applied by larger manufacturer. Hence, this study is limited to the analysis of questionnaires filled in by producers that have more than 50 employees. We analyze the leadership styles of two managers, namely the CEO and production manager.
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Nursing shortages still exist in the U.S. so it is important to determine factors that influence decisions to pursue nursing as a career. This comparative, correlational research study revealed factors that may contribute to, or deter students from choosing nursing as a career. The purpose of this study was to determine factors that contribute to a career choice for nursing based on the concepts of social cognitive career theory (SCCT), self efficacy, outcome expectations, and personal goals, among senior high school students, final year nursing students, and first year nursing students. Based on the results strategies may be developed to recruit a younger pool of students to the nursing profession and to boost retention efforts among those who already made a career choice in nursing. Data were collected using a three part questionnaire developed by the researcher to obtain demographic information and data about the respondents' self efficacy, outcome expectations, and personal goals with regards to nursing as a career. Point bi-serial correlations were used to determine relationships between the variables. ANOVAs and ANCOVAs were computed to determine differences in self efficacy and outcome expectations, among the three groups. Additional descriptive data determined reasons for and against a choice for nursing as a career. Self efficacy and outcome expectations were significantly correlated to career choice among all three groups. The nursing students had higher self efficacy perceptions than the high school students. There were no significant differences in outcome expectations between the three groups. The main categories identified as reasons for choosing nursing as a career were; (a) caring, (b) career and educational advancement, (c) personal accomplishment, (d) proficiency and love of the medical field. Common categories identified for not choosing nursing as a career were; (a) responsibility, (b) liability, (c) lack of respect, and (d) low salary. Other categories regarding not choosing nursing as a career included; (a) the nursing program and (b) professional (c) alternate career choice options and (d) fear of sickness and death. Findings from this study support the tenets of SCCT and may be used to recruit and retain nurses and develop curricula.
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The challenge that continues to face HRD is how to integrate real concerns for diversity into programs, practices, and research. Critical race theory was used as a lens to examine work on diversity published in Human Resource Development Quarterly (HRDQ). Eight publications were selected and analyzed.
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Given the growing number of wrongful convictions involving faulty eyewitness evidence and the strong reliance by jurors on eyewitness testimony, researchers have sought to develop safeguards to decrease erroneous identifications. While decades of eyewitness research have led to numerous recommendations for the collection of eyewitness evidence, less is known regarding the psychological processes that govern identification responses. The purpose of the current research was to expand the theoretical knowledge of eyewitness identification decisions by exploring two separate memory theories: signal detection theory and dual-process theory. This was accomplished by examining both system and estimator variables in the context of a novel lineup recognition paradigm. Both theories were also examined in conjunction with confidence to determine whether it might add significantly to the understanding of eyewitness memory. ^ In two separate experiments, both an encoding and a retrieval-based manipulation were chosen to examine the application of theory to eyewitness identification decisions. Dual-process estimates were measured through the use of remember-know judgments (Gardiner & Richardson-Klavehn, 2000). In Experiment 1, the effects of divided attention and lineup presentation format (simultaneous vs. sequential) were examined. In Experiment 2, perceptual distance and lineup response deadline were examined. Overall, the results indicated that discrimination and remember judgments (recollection) were generally affected by variations in encoding quality and response criterion and know judgments (familiarity) were generally affected by variations in retrieval options. Specifically, as encoding quality improved, discrimination ability and judgments of recollection increased; and as the retrieval task became more difficult there was a shift toward lenient choosing and more reliance on familiarity. ^ The application of signal detection theory and dual-process theory in the current experiments produced predictable results on both system and estimator variables. These theories were also compared to measures of general confidence, calibration, and diagnosticity. The application of the additional confidence measures in conjunction with signal detection theory and dual-process theory gave a more in-depth explanation than either theory alone. Therefore, the general conclusion is that eyewitness identifications can be understood in a more complete manor by applying theory and examining confidence. Future directions and policy implications are discussed. ^
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The goal of the power monitoring in electrical power systems is to promote the reliablility as well as the quality of electrical power.Therefore, this dissertation proposes a new theory of power based on wavelet transform for real-time estimation of RMS voltages and currents, and some power amounts, such as active power, reactive power, apparent power, and power factor. The appropriate estimation the of RMS and power values is important for many applications, such as: design and analysis of power systems, compensation devices for improving power quality, and instruments for energy measuring. Simulation and experimental results obtained through the proposed MaximalOverlap Discrete Wavelet Transform-based method were compared with the IEEE Standard 1459-2010 and the commercial oscilloscope, respectively, presenting equivalent results. The proposed method presented good performance for compact mother wavelet, which is in accordance with real-time applications.
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This research is investigating the claim that Change Data Capture (CDC) technologies capture data changes in real-time. Based on theory, our hypothesis states that real-time CDC is not achievable with traditional approaches (log scanning, triggers and timestamps). Traditional approaches to CDC require a resource to be polled, which prevents true real-time CDC. We propose an approach to CDC that encapsulates the data source with a set of web services. These web services will propagate the changes to the targets and eliminate the need for polling. Additionally we propose a framework for CDC technologies that allow changes to flow from source to target. This paper discusses current CDC technologies and presents the theory about why they are unable to deliver changes in real-time. Following, we discuss our web service approach to CDC and accompanying framework, explaining how they can produce real-time CDC. The paper concludes with a discussion on the research required to investigate the real-time capabilities of CDC technologies. © 2010 IEEE.
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This paper examines the related but different concepts of the uncanny and the sacred. Drawing on two cases – one fictional and one real – and using Žižek’s Symbolic-Real-Imaginary as an organising frame, the paper analyses how the uncanny and the sacred are connected. It then proceeds to examine the role of theorising in sacralising the uncanny and profaning the sacred. Finally, it briefly discusses how theory might be re-enchanted.
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This paper examines the remarkable and unexplored correspondence between games (and board games in particular) and what is commonly understood as theory in the social sciences. It argues that games exhibit many if not most of the attributes of theory, but that theory is missing some of the features of games. As such, game provide a way of rethinking what we mean by theory and theorizing. Specifically, games and their relationship with the ‘real’ world, provide a way of thinking about theory and theorizing that is consistent with recent calls to frame social inquiry around the concept of phrónēsis.