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Articles 12781 - 12810 of 21224

Full-Text Articles in Social and Behavioral Sciences

Nigerian Stock Index: A Search For Optimal Garch Model Using High Frequency Data, Olaoluwa Simon Yaya Dec 2013

Nigerian Stock Index: A Search For Optimal Garch Model Using High Frequency Data, Olaoluwa Simon Yaya

CBN Journal of Applied Statistics (JAS)

This paper attempts to fit the best Generalized Autoregressive Conditional Heteroscedastic (GARCH) model for All Share Index (ASI) of Nigerian Stock Exchange (NSE) returns. A search is made on various GARCH variants specified on the assumptions of stationarity and asymmetry. Fractionally integrated types are also considered to capture the possibility of return series having property of long range dependency. The parameter estimations are carried out on the assumptions of normality and non-normality of GARCH innovations, with models and forecasts evaluated using information criteria and loss functions respectively. Under normality assumption, Hyperbolic GARCH (HYGARCH(1,d,1)) model is selected and Integrated GARCH (IGARCH(1,1)) …

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Time Series Modeling Of Nigeria External Reserves, Iheanyichukwu S. Iwueze, Eleazar C. Nwogu, Valentine U. Nlebedim Dec 2013

Time Series Modeling Of Nigeria External Reserves, Iheanyichukwu S. Iwueze, Eleazar C. Nwogu, Valentine U. Nlebedim

CBN Journal of Applied Statistics (JAS)

This paper discusses the levels and trend of external reserves in Nigeria. The relevance of this lies in the fact that it could help to monitor the reserves and throw early warning signal about any economic crisis. Monthly data on Nigeria external reserves for the period January 1999 to December, 2008 derived from the 2008 CBN Statistical Bulletin was analyzed using ARIMA model. Results of the analyses show that (i) the data requires logarithmic transformation to stabilize the variance and make the distribution normal (ii) the appropriate model that best describes the pattern in the transformed data is the Autoregressive- …

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A Markov Decision Process Approach To Optimal Control Of A Multi-Level Hierarchical Manpower System, Akaninyene U. Udom Dec 2013

A Markov Decision Process Approach To Optimal Control Of A Multi-Level Hierarchical Manpower System, Akaninyene U. Udom

CBN Journal of Applied Statistics (JAS)

A recurrent problem in manpower control is how to attain the desired structural configuration in an optimal way, since it is possible to reach a desired structural configuration using different control inputs. The major aim of this paper is to develop a Markov Decision Process for optimal control of a Multi-level Hierarchical Manpower System (MHMS) by promotion and interdepartmental transfers. This is examined under control by intervention and contraction cost Markov Decision Process.

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Singapore Management University Wins Inaugural Teradata University Network Teaching Innovation Award, Singapore Management University Dec 2013

Singapore Management University Wins Inaugural Teradata University Network Teaching Innovation Award, Singapore Management University

SMU Press Releases and News

Teradata Corporation, a leading global provider of analytic data platforms, marketing applications and analytics related consulting services, announced today the winner of the 2013 Teradata University Network (TUN) Teaching Innovation Award. Associate Professor Michelle Cheong and Mr Murphy Choy from the School of Information Systems at Singapore Management University (SMU) received the Award for their teaching case on "Effective Use of Data & Decision Analytics to Improve Order Distribution in a Supply Chain".

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For Logs, For Traditional Purposes And For Food: Identification Of Multiple-Use Plant Species Of Northern Amazonia And An Assessment Of Factors Associated With Their Distribution, Anthony Ravindra Cummings Dec 2013

For Logs, For Traditional Purposes And For Food: Identification Of Multiple-Use Plant Species Of Northern Amazonia And An Assessment Of Factors Associated With Their Distribution, Anthony Ravindra Cummings

Dissertations - ALL

This dissertation examines the multiplicity of uses associated with tree and palm species of the Rupununi, Southern Guyana and the factors associated with their distribution. As tropical forests continue to decline the most significant response has been to understand the implications for the carbon cycle, with the impacts on forest dwelling peoples and wildlife, inadequately addressed. Multiple-use plants, individual species which at their most critical level provide food for wildlife, non-timber forest products and are commercially logged, provide a suitable lens for appreciating additional ecosystem services that may be compromised as tropical forests decline. I completed a plant inventory in …

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Mapping Vegetation Productivity Dynamics And Degradation Trends Over East Africa Using A Decade Of Medium Resolution Modis Time-Series Data, Tobias Landmann, Olena Dubovyk Dec 2013

Mapping Vegetation Productivity Dynamics And Degradation Trends Over East Africa Using A Decade Of Medium Resolution Modis Time-Series Data, Tobias Landmann, Olena Dubovyk

All Peer-Reviewed Publications

This paper aims to characterize spatial and temporal vegetation productivity trends that could be related to land degradation in East Africa. A decade of AQUA/TERRA-Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations on vegetation chlorophyll activity, or Normalized Differential Vegetation Index (NDVI) data, and 25-km rainfall data from the TRMM passive radar instrument were used for the same observation period of 2000-2011. Linear trends in land cover based Rain Use Efficiencies (RUE) corrected NDVI and cumulative differences of RUE between consecutive years from 2000 to 2011 (that is amplitudes) were derived and investigated for their robustness. The trend maps were overlaid …

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Two Formulas For Success In Social Media: Social Learning And Network Effects, Liangfei Qiu, Qian Tang, Andrew B. Whinston Dec 2013

Two Formulas For Success In Social Media: Social Learning And Network Effects, Liangfei Qiu, Qian Tang, Andrew B. Whinston

Research Collection School Of Computing and Information Systems

This paper examines social learning and network effects that are particularly important for online videos, considering the limited marketing campaigns of user-generated content. Rather than combining both social learning and network effects under the umbrella of social contagion or peer influence, we develop a theoretical model and empirically identify social learning and network effects separately. Using a unique data set from YouTube, we find that both mechanisms have statistically and economically significant effects on video views, and which mechanism dominates depends on the specific video type.

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Bedrock Geological Map Of The Rockhouse Quadrangle, Carroll And Madison Counties, Arkansas, Douglas Eben Jones Dec 2013

Bedrock Geological Map Of The Rockhouse Quadrangle, Carroll And Madison Counties, Arkansas, Douglas Eben Jones

Graduate Theses and Dissertations

A digital geologic map of the Rockhouse quadrangle, Carroll and Madison counties, Arkansas, was created on a 1:24,000 scale using ArcMap 10 and Photoshop CS4. The data obtained in the field are digitized onto the United States Geological Survey (USGS) digital raster graphic (DRG) of the Rockhouse quadrangle. The geology in the Rockhouse quadrangle consist entirely of sedimentary rocks that are Paleozoic ranging from Lower Ordovician to Mississippian in age. The Ordovician System is represented by the Cotter, Powell, Everton, and St. Peter Formations. The Cotter and Powell are the prominent bluff forming units throughout the quadrangle and along the …

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Factors Influencing Research Contributions And Researcher Interactions In Software Engineering: An Empirical Study, Subhajit Datta, A. S. M. Sajeev, Santonu Sarkar, Nishant Kumar Dec 2013

Factors Influencing Research Contributions And Researcher Interactions In Software Engineering: An Empirical Study, Subhajit Datta, A. S. M. Sajeev, Santonu Sarkar, Nishant Kumar

Research Collection School Of Computing and Information Systems

Research into software engineering (SE) education is largely concentrated on teaching and learning issues in coursework programs. This paper, in contrast, provides a meta analysis of research publications in software engineering to help with research education in SE. Studying publication patterns in a discipline will assist research students and supervisors gain a deeper understanding of how successful research has occurred in the discipline. We present results from a large scale empirical study covering over three and a half decades of software engineering research publications. We identify how different factors of publishing relate to the number of papers published as well …

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Determining The Feasibility Of Implementing An Effective Fungiculture Program With The Peace Garden At Illinois Wesleyan University, Mackenzie Rivkin '14 Dec 2013

Determining The Feasibility Of Implementing An Effective Fungiculture Program With The Peace Garden At Illinois Wesleyan University, Mackenzie Rivkin '14

Outstanding Senior Seminar Papers

The Peace Garden at Illinois Wesleyan University (IWU), the organic garden at the small liberal-arts university in Bloomington, Illinois, is devoted to growing nutritious, pesticide-free food to be sold locally in an attempt to counterbalance the various food-related issues which stem from conventional food systems. Mushrooms, fungi with many nutritional benefits, are not currently produced by the Peace Garden. However, the unique nature of mushrooms may be attractive to certain consumers and could further contribute to the Peace Garden's mission if produced. This study, conducted September to December 2013 is guided by the following question: What is the feasibility of …

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Topicsketch: Real-Time Bursty Topic Detection From Twitter, Wei Xie, Feida Zhu, Jing Jiang, Ee Peng Lim, Ke Wang Dec 2013

Topicsketch: Real-Time Bursty Topic Detection From Twitter, Wei Xie, Feida Zhu, Jing Jiang, Ee Peng Lim, Ke Wang

Research Collection School Of Computing and Information Systems

Twitter has become one of the largest platforms for users around the world to share anything happening around them with friends and beyond. A bursty topic in Twitter is one that triggers a surge of relevant tweets within a short time, which often reflects important events of mass interest. How to leverage Twitter for early detection of bursty topics has therefore become an important research problem with immense practical value. Despite the wealth of research work on topic modeling and analysis in Twitter, it remains a huge challenge to detect bursty topics in real-time. As existing methods can hardly scale …

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Balancing The Presentation Of Information And Options In Patient Decision Aids: An Updated Review, Purva Abhyankar, Robert J. Volk, Jennifer Blumenthal-Barby, Paulina Bravo, Angela Buchholz, Elissa Ozanne, Dale C. Vidal, Nananda Col, Peep Stalmeier Nov 2013

Balancing The Presentation Of Information And Options In Patient Decision Aids: An Updated Review, Purva Abhyankar, Robert J. Volk, Jennifer Blumenthal-Barby, Paulina Bravo, Angela Buchholz, Elissa Ozanne, Dale C. Vidal, Nananda Col, Peep Stalmeier

Dartmouth Scholarship

Standards for patient decision aids require that information and options be presented in a balanced manner; this requirement is based on the argument that balanced presentation is essential to foster informed decision making. If information is presented in an incomplete/non-neutral manner, it can stimulate cognitive biases that can unduly affect individuals’ knowledge, perceptions of risks and benefits, and, ultimately, preferences. However, there is little clarity about what constitutes balance, and how it can be determined and enhanced. We conducted a literature review to examine the theoretical and empirical evidence related to balancing the presentation of information and options.

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Meeting Minutes, Wku University Senate Nov 2013

Meeting Minutes, Wku University Senate

Faculty Senate

Meeting regarding meeting procedures, budget, faculty vacancies, accreditation, Information Technology policies, electronic mail, Colonnade plan, SITE evaluations, and faculty governance.

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Imls Place Grant: Campus Journal Press Release, Place Project Group Nov 2013

Imls Place Grant: Campus Journal Press Release, Place Project Group

PLACE Project

Campus Journal press release describing the PLACE (Position-based Location Archive Coordinate Explorer) project that is funded by the Institute for Museum and Library Services. The University of New Hampshire (UNH) library partnered with the UNH Earth Systems Research Center to develop a geospatial interface that is searchable by geospatial coordinates.

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Telling Stories With Web Archives, Michele C. Weigle Nov 2013

Telling Stories With Web Archives, Michele C. Weigle

Computer Science Presentations

PDF of a powerpoint presentation from the Southeast Women in Computing Conference in Lake Guntersville State Park, Alabama, November 16, 2013. Also available on Slideshare.

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The Santa Clara, 2013-11-14, Santa Clara University Nov 2013

The Santa Clara, 2013-11-14, Santa Clara University

The Santa Clara

No abstract provided.

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Gathering "Wild" Food In The City: Rethinking The Role Of Foraging In Urban Ecosystem Planning And Management, Rebecca J. Mclain, Patrick T. Hurley, Marla R. Emery, Melissa R. Poe Nov 2013

Gathering "Wild" Food In The City: Rethinking The Role Of Foraging In Urban Ecosystem Planning And Management, Rebecca J. Mclain, Patrick T. Hurley, Marla R. Emery, Melissa R. Poe

Environment and Sustainability Faculty Publications

Recent “green” planning initiatives envision food production, including urban agriculture and livestock production, as desirable elements of sustainable cities. We use an integrated urban political ecology and human–plant geographies framework to explore how foraging for “wild” foods in cities, a subversive practice that challenges prevailing views about the roles of humans in urban green spaces, has potential to also support sustainability goals. Drawing on research from Baltimore, New York City, Philadelphia, and Seattle, we show that foraging is a vibrant and ongoing practice among diverse urban residents in the USA. At the same time, as reflected in regulations, planning practices, …

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On The Causal Interpretation Of Race In Regressions Adjusting For Confounding And Mediating Variables, Tyler J. Vanderweele, Whitney Robinson Nov 2013

On The Causal Interpretation Of Race In Regressions Adjusting For Confounding And Mediating Variables, Tyler J. Vanderweele, Whitney Robinson

Harvard University Biostatistics Working Paper Series

We consider different possible interpretations of the “effect of race” when regressions are run with race as an exposure variable, controlling also for various confounding and mediating variables. When adjustment is made for socioeconomic status early in a person's life, we discuss under what contexts the regression coefficients for race can be interpreted as corresponding to the extent to which a racial disparity would remain if various socioeconomic distributions early in life across racial groups could be equalized. When adjustment is also made for adult socioeconomic status, we note how the overall disparity can be decomposed into the portion that …

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The Santa Clara, 2013-11-07, Santa Clara University Nov 2013

The Santa Clara, 2013-11-07, Santa Clara University

The Santa Clara

No abstract provided.

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Unh Library Imls Place Grant News Announcement, Place Project Group Nov 2013

Unh Library Imls Place Grant News Announcement, Place Project Group

PLACE Project

UNH Library Website News announcement about the IMLS Grant for PLACE, November 7, 2014.

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Food Sovereignty: An Alternative Paradigm For Poverty Reduction And Biodiversity Conservation In Latin America, M Jahi Chappell, Hannah Wittman, Christopher M. Bacon, Bruce G. Ferguson, Luis García Barrios, Raúl García Barrios, Daniel Jaffee, Jefferson Lima, V. Ernesto Méndez,, Helda Morales, Lorena Soto-Pinto, John Vandermeer, Ivette Perfecto Nov 2013

Food Sovereignty: An Alternative Paradigm For Poverty Reduction And Biodiversity Conservation In Latin America, M Jahi Chappell, Hannah Wittman, Christopher M. Bacon, Bruce G. Ferguson, Luis García Barrios, Raúl García Barrios, Daniel Jaffee, Jefferson Lima, V. Ernesto Méndez,, Helda Morales, Lorena Soto-Pinto, John Vandermeer, Ivette Perfecto

Environmental Studies and Sciences

Strong feedback between global biodiversity loss and persistent, extreme rural poverty are major challenges in the face of concurrent food, energy, and environmental crises. This paper examines the role of industrial agricultural intensification and market integration as exogenous socio-ecological drivers of biodiversity loss and poverty traps in Latin America. We then analyze the potential of a food sovereignty framework, based on protecting the viability of a diverse agroecological matrix while supporting rural livelihoods and global food production. We review several successful examples of this approach, including ecological land reform in Brazil, agroforestry, milpa, and the uses of wild varieties in …

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The Western Kentucky University Crumps Cave Research & Education Preserve, Chris Groves, Jason Polk, Ben Miller, Pat Kambesis, Carl Bolster, Sean Vanderhoff, Beth Tyrie Nov 2013

The Western Kentucky University Crumps Cave Research & Education Preserve, Chris Groves, Jason Polk, Ben Miller, Pat Kambesis, Carl Bolster, Sean Vanderhoff, Beth Tyrie

Earth, Environmental, and Atmospheric Sciences Faculty Publications

Crumps Cave is located about one kilometer northeast of Smiths Grove, Kentucky (Figures 1, 2, and 3). The only known entrance was purchased by Western Kentucky University (WKU) in 2009 through a grant from the Kentucky Heritage Land Conservation Fund and the cave is managed as the focal point of a research and education preserve to study a wide range of environmental conditions and dynamics, and their interactions, using high-resolution electronic monitoring along with geochemical sampling, analysis and modeling. Crews from WKU’s Hoffman Environmental Research Institute visit the cave weekly for sampling, data downloading, and equipment maintenance, with a major …

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Caver Quest 3d Virtual Cave Simulation Of Snowy River In Fort Stanton Cave, Ronald J. Lipinski, Pete Lindsley Nov 2013

Caver Quest 3d Virtual Cave Simulation Of Snowy River In Fort Stanton Cave, Ronald J. Lipinski, Pete Lindsley

National Cave and Karst Management Symposium 2013

Virtual worlds, or 3D simulations through which an avatar can travel, is becoming a common means to display products or provide training in new environments. This paper describes the steps in producing the 3D virtual simulation of Snowy River in Fort Stanton Cave, New Mexico. A traditional cave survey and map with cross sections was used to produce a 3D meshed surface of the cave walls using the Blender software package. Photographs were taken of the walls, ceiling, and floor and merged together. The merged montage was applied to the 3D mesh walls as a “texture”. Unity3D was used to …

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A Monte Carlo Comparison Of Robust Manova Test Statistics, Holmes Finch, Brian French Nov 2013

A Monte Carlo Comparison Of Robust Manova Test Statistics, Holmes Finch, Brian French

Journal of Modern Applied Statistical Methods

Multivariate Analysis of Variance (MANOVA) is a popular statistical tool in the social sciences, allowing for the comparison of mean vectors across groups. MANOVA rests on three primary assumptions regarding the population: (a) multivariate normality, (b) equality of group population covariance matrices and (c) independence of errors. When these assumptions are violated, MANOVA does not perform well with respect to Type I error and power. There are several alternative test statistics that can be considered including robust statistics and the use of the structural equation modeling (SEM) framework. This simulation study focused on comparing the performance of the P test …

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On Some Properties Of A Heterogeneous Transfer Function Involving Symmetric Saturated Linear (Satlins) With Hyperbolic Tangent (Tanh) Transfer Functions, Christopher Godwin Udomboso Nov 2013

On Some Properties Of A Heterogeneous Transfer Function Involving Symmetric Saturated Linear (Satlins) With Hyperbolic Tangent (Tanh) Transfer Functions, Christopher Godwin Udomboso

Journal of Modern Applied Statistical Methods

For transfer functions to map the input layer of the statistical neural network model to the output layer perfectly, they must lie within bounds that characterize probability distributions. The heterogeneous transfer function, SATLINS_TANH, is established as a Probability Distribution Function (p.d.f), and its mean and variance are shown.

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Distribution Of The Ratio Of Normal And Rice Random Variables, Nayereh B. Khoolenjani, Kavoos Khorshidian Nov 2013

Distribution Of The Ratio Of Normal And Rice Random Variables, Nayereh B. Khoolenjani, Kavoos Khorshidian

Journal of Modern Applied Statistical Methods

The ratio of independent random variables arises in many applied problems. The distribution of the ratio |X/Y| is studied when X and Y are independent Normal and Rice random variables, respectively. Ratios of such random variables have extensive applications in the analysis of noises in communication systems. The exact forms of probability density function (PDF), cumulative distribution function (CDF) and the existing moments are derived in terms of several special functions. As a special case, the PDF and CDF of the ratio of independent standard Normal and Rayleigh random variables have been obtained. Tabulations of associated percentage points …

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Front Matter, Jmasm Editors Nov 2013

Front Matter, Jmasm Editors

Journal of Modern Applied Statistical Methods

No abstract provided.

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Preliminary Testing For Normality: Is This A Good Practice?, H. J. Keselman, Abdul R. Othman, Rand R. Wilcox Nov 2013

Preliminary Testing For Normality: Is This A Good Practice?, H. J. Keselman, Abdul R. Othman, Rand R. Wilcox

Journal of Modern Applied Statistical Methods

Normality is a distributional requirement of classical test statistics. In order for the test statistic to provide valid results leading to sound and reliable conclusions this requirement must be satisfied. In the not too distant past, it was claimed that violations of normality would not likely jeopardize scientific findings (See Hsu & Feldt, 1969; Lunney, 1970). Recent revelations suggest otherwise (See e.g., Micceri, 1989; Keselman, Huberty, Lix et al., 1998; Erceg-Hurn, Wilcox, & Keselman, 2013; Wilcox and Keselman, 2003; Wilcox, 2012a, b). Unfortunately the data obtained in psychological investigations rarely, if ever, meet the requirement of normally distributed data (Micceri, …

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Intrinsically Ties Adjusted Non-Parametric Method For The Analysis Of Two Sampled Data, G. U. Ebuh, I. C. A Oyeka Nov 2013

Intrinsically Ties Adjusted Non-Parametric Method For The Analysis Of Two Sampled Data, G. U. Ebuh, I. C. A Oyeka

Journal of Modern Applied Statistical Methods

A non-parametric method for the analysis of two sample data is proposed that intrinsically and structurally adjusts the test statistic for the possible presence of tied observations between the sampled populations, thereby obviating the need to require the populations to be continuous. The populations may be measurements on as low as the ordinal scale, and need not be homogeneous. In cases where the null hypotheses are rejected, the test statistic enables the determination of which of the sampled populations is likely to be responsible for the rejection (a determination which the Wilcoxon Mann Whitney test cannot handle). The proposed method …

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The Impact Of Continuity Violation On Anova And Alternative Methods, Björn Lantz Nov 2013

The Impact Of Continuity Violation On Anova And Alternative Methods, Björn Lantz

Journal of Modern Applied Statistical Methods

The normality assumption behind ANOVA and other parametric methods implies that response variables are measured on continuous scales. A simulation approach is used to explore the impact of continuity violation on the performance of statistical methods commonly used by applied researchers to compare locations across several groups.

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