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Showing papers by "University of Colorado Colorado Springs published in 2011"


Journal ArticleDOI
TL;DR: In this paper, a review of the recent developments in the field of research for new catalysts for glycerol is presented, which highlights the role of reaction conditions as well as the possible transport limitations in this tri-phasic system.

450 citations


Journal ArticleDOI
TL;DR: This article performed an extensive co-citation analysis using multidimensional scaling to examine 76,342 citations made in 1,320 sustainability-focused articles from 36 journals over 51 years (1958-2008).
Abstract: Recent changes in the business environment have prompted marketing scholars to pay particular attention to sustainability as a topic of inquiry. Despite the progress made in the study of sustainability, there is a paucity of research on the topic in premier marketing journals. To address this issue, we focus on marketing-related journals and assess the intellectual structure of sustainability research in detail. Drawing on social network theory, we perform an extensive co-citation analysis using multidimensional scaling to examine 76,342 citations made in 1,320 sustainability-focused articles from 36 journals over 51 years (1958–2008). This study specifies that the topics of citizenship behavior, stakeholder theory, corporate performance, and the triple bottom line are integral sustainability research areas. In addition, the results indicate five required topics for examining sustainability in the marketing context: external-internal focus, social-environmental emphasis, legal-ethical-discretionary intent, marketing assets, and financial performance. Supported by the capabilities-based resource perspective, the sustainability-focused typology and framework advanced provide directed structure for future research.

403 citations


Journal ArticleDOI
TL;DR: The Science Teachers Learning from Lesson Analysis (STeLLA) project as discussed by the authors is a videobased analysis-of-practice PD program aimed at improving teacher and student learning at the upper elementary level.
Abstract: The Science Teachers Learning from Lesson Analysis (STeLLA) project is a videobased analysis-of-practice PD program aimed at improving teacher and student learning at the upper elementary level. The PD program developed and utilized two “lenses,” a Science Content Storyline Lens and a Student Thinking Lens, to help teachers analyze science teaching and learning and to improve teaching practices in this year-long program. Participants included 48 teachers (n = 32 experimental, n = 16 control) and 1,490 students. The STeLLA program significantly improved teachers' science content knowledge and their ability to analyze science teaching. Notably, the STeLLA teachers further increased their classroom use of science teaching strategies associated with both lenses while their students increased their science content knowledge. Multi-level HLM analyses linked higher average gains in student learning with teachers' science content knowledge, teachers' pedagogical content knowledge about student thinking, and teaching practices aimed at improving the coherence of the science content storyline. This paper highlights the importance of the science content storyline in the STeLLA program and discusses its potential significance in science teaching and professional development more broadly. © 2011 Wiley Periodicals, Inc., J Res Sci Teach 48: 117–148, 2011

301 citations


Journal ArticleDOI
TL;DR: The causes of failure and the evaluation of the patient with recurrent instability are summarized and a review of the literature regarding results after revision ACL reconstruction was performed to assist in the decision-making process and patient counseling.
Abstract: Revision reconstruction of the anterior cruciate ligament (ACL) introduces several diagnostic and technical challenges in comparison with primary ACL reconstruction. With the increasing numbers of original reconstructions combined with the continued expectation of high-level athletic participation, revision ACL reconstruction is likely to become more frequent. The purpose of this article was to summarize the causes of failure and the evaluation of the patient with recurrent instability. A review of the literature regarding results after revision ACL reconstruction was performed to assist in the decision-making process and patient counseling. Good results can be obtained in terms of functional stability after revision reconstruction, but chondral and meniscal injury as well as unrecognized associated pathologic instability may play a role in diminished outcomes. In addition, a wide variety of surgical techniques are reviewed to address problems associated with tunnel malposition, widening, and pre-existing hardware.

285 citations


Journal ArticleDOI
TL;DR: In this paper, the authors review past transitions and factors behind them, along with their time frames, and identify several policy instruments to accelerate a transition, though even under ideal circumstances a global energy supply transition will be very slow.

267 citations


Journal ArticleDOI
TL;DR: The emerging field of digital image forensics is introduced, including the main topic areas of source camera identification, forgery detection, and steganalysis, including a critical analysis of the state of the art, and recommendations for the direction of future research.
Abstract: Digital images are everywhere—from our cell phones to the pages of our online news sites. How we choose to use digital image processing raises a surprising host of legal and ethical questions that we must address. What are the ramifications of hiding data within an innocent imageq Is this an intentional security practice when used legitimately, or intentional deceptionq Is tampering with an image appropriate in cases where the image might affect public behaviorq Does an image represent a crime, or is it simply a representation of a scene that has never existedq Before action can even be taken on the basis of a questionable image, we must detect something about the image itself. Investigators from a diverse set of fields require the best possible tools to tackle the challenges presented by the malicious use of today's digital image processing techniques.In this survey, we introduce the emerging field of digital image forensics, including the main topic areas of source camera identification, forgery detection, and steganalysis. In source camera identification, we seek to identify the particular model of a camera, or the exact camera, that produced an image. Forgery detection's goal is to establish the authenticity of an image, or to expose any potential tampering the image might have undergone. With steganalysis, the detection of hidden data within an image is performed, with a possible attempt to recover any detected data. Each of these components of digital image forensics is described in detail, along with a critical analysis of the state of the art, and recommendations for the direction of future research.

266 citations


Journal ArticleDOI
TL;DR: In this article, the authors discuss the need to incorporate socioscientific ideas into the science curricula more thoroughly and discuss the state-of-the-art, potentials, and barriers of effective implementation.
Abstract: One common theme underlying recent reports on science education is that the content of school science and its related pedagogical approaches are not aligned with the interests and needs of both society and the majority of the students. Most students do not find their science classes interesting and motivating. These claims are especially valid regarding those students who, in the future, will probably not embark on a career in science or engineering but will need science and technology personally and functionally as literate citizens. One key problem seems to be that few science programs around the world teach how science is linked to those issues that are relevant to students’ life, environment, and role as a citizen. As a result, many students are unable to participate in societal discussions about science and its related technological applications. This paper discusses the need to incorporate socioscientific ideas into the science curricula more thoroughly. This recommendation is supported by a theoretical rationale from various sources leading to a reflection about common practices in science education in three countries: Israel, Germany, and the USA. The state-of-the-art, potentials, and barriers of effective implementation are discussed.

248 citations


Journal ArticleDOI
TL;DR: The literature behind both lines of investigation is reviewed and includes special diagnostic and clinical considerations for at risk populations.

232 citations


Journal ArticleDOI
TL;DR: In this article, the structure of alumina-supported cobalt catalysts promoted with platinum and their catalytic performance in Fischer-Tropsch synthesis were investigated under realistic reaction conditions.

226 citations


Journal ArticleDOI
TL;DR: A comprehensive survey of well-known distance-based, density-based and other techniques for outlier detection and compare them is presented and definitions of outliers are provided and their detection based on supervised and unsupervised learning in the context of network anomaly detection are discussed.
Abstract: The detection of outliers has gained considerable interest in data mining with the realization that outliers can be the key discovery to be made from very large databases. Outliers arise due to various reasons such as mechanical faults, changes in system behavior, fraudulent behavior, human error and instrument error. Indeed, for many applications the discovery of outliers leads to more interesting and useful results than the discovery of inliers. Detection of outliers can lead to identification of system faults so that administrators can take preventive measures before they escalate. It is possible that anomaly detection may enable detection of new attacks. Outlier detection is an important anomaly detection approach. In this paper, we present a comprehensive survey of well-known distance-based, density-based and other techniques for outlier detection and compare them. We provide definitions of outliers and discuss their detection based on supervised and unsupervised learning in the context of network anomaly detection.

217 citations


Journal ArticleDOI
TL;DR: A new statistical predictor based upon the Weibull distribution is developed, which produces accurate results on a per instance recognition basis across different recognition problems.
Abstract: In this paper, we define meta-recognition, a performance prediction method for recognition algorithms, and examine the theoretical basis for its postrecognition score analysis form through the use of the statistical extreme value theory (EVT). The ability to predict the performance of a recognition system based on its outputs for each match instance is desirable for a number of important reasons, including automatic threshold selection for determining matches and nonmatches, and automatic algorithm selection or weighting for multi-algorithm fusion. The emerging body of literature on postrecognition score analysis has been largely constrained to biometrics, where the analysis has been shown to successfully complement or replace image quality metrics as a predictor. We develop a new statistical predictor based upon the Weibull distribution, which produces accurate results on a per instance recognition basis across different recognition problems. Experimental results are provided for two different face recognition algorithms, a fingerprint recognition algorithm, a SIFT-based object recognition system, and a content-based image retrieval system.

Journal ArticleDOI
TL;DR: In this article, the authors show that traditional methods of estimating battery cell total capacity, which consider noises only in the accumulated ampere hour measurement, are biased and derive an approximate weighted total least squares algorithm that is suitable for implementation in an embedded battery management system.

Proceedings ArticleDOI
01 Oct 2011
TL;DR: This paper compares algorithms for extractive summarization of micro log posts with two algorithms that produce summaries by selecting several posts from a given set.
Abstract: Due to the sheer volume of text generated by a micro log site like Twitter, it is often difficult to fully understand what is being said about various topics. In an attempt to understand micro logs better, this paper compares algorithms for extractive summarization of micro log posts. We present two algorithms that produce summaries by selecting several posts from a given set. We evaluate the generated summaries by comparing them to both manually produced summaries and summaries produced by several leading traditional summarization systems. In order to shed light on the special nature of Twitter posts, we include extensive analysis of our results, some of which are unexpected.

Journal ArticleDOI
TL;DR: This survey provides a comparison of port scan methods based on type, mode of detection, mechanism used for detection and other characteristics, and reports on the available data sets and evaluation criteria for port scan detection approaches.
Abstract: Scanning of ports on a computer occurs frequently on the Internet. An attacker performs port scans of Internet protocol addresses to find vulnerable hosts to compromise. However, it is also useful for system administrators and other network defenders to detect port scans as possible preliminaries to more serious attacks. It is a very difficult task to recognize instances of malicious port scanning. In general, a port scan may be an instance of a scan by attackers or an instance of a scan by network defenders. In this survey, we present research and development trends in this area. Our presentation includes a discussion of common port scan attacks. We provide a comparison of port scan methods based on type, mode of detection, mechanism used for detection and other characteristics. This survey also reports on the available data sets and evaluation criteria for port scan detection approaches.

Journal ArticleDOI
TL;DR: CT scanning of patients with stiff TKAs is recommended before surgical intervention to identify the presence of internally rotated components, and if revision altered nonrotational radiographic parameters.
Abstract: Background Stiffness complicating TKA is a complex and multifactorial problem. We suspected internally rotated components compromised motion because of pain, patellar maltracking, a tight medial flexion gap, and limited femoral rollback on a conforming lateral tibial condyle.

Journal ArticleDOI
TL;DR: In this article, the authors used sparse photometry from selected observatories from the AstDyS database (Asteroids- Dynamic Site), either alone or in combination with dense lightcurves, to determine new asteroid models by the lightcurve inversion method.
Abstract: Context. In the past decade, more than one hundred asteroid models were derived using the lightcurve inversion method. Measured by the number of derived models, lightcurve inversion has become the leading method for asteroid shape determination. Aims. Tens of thousands of sparse-in-time lightcurves from astrometric projects are publicly available. We investigate these data and use them in the lightcurve inversion method to derive new asteroid models. By having a greater number of models with known physical properties, we can gain a better insight into the nature of individual objects and into the whole asteroid population. Methods. We use sparse photometry from selected observatories from the AstDyS database (Asteroids – Dynamic Site), either alone or in combination with dense lightcurves, to determine new asteroid models by the lightcurve inversion method. We investigate various correlations between several asteroid parameters and characteristics such as the rotational state and diameter or family membership. We focus on the distribution of ecliptic latitudes of pole directions. We create a synthetic uniform distribution of latitudes, compute the method bias, and compare the results with the distribution of known models. We also construct a model for the long-term evolution of spins. Results. We present 80 new asteroid models derived from combined data sets where sparse photometry is taken from the AstDyS database and dense lightcurves are from the Uppsala Asteroid Photometric Catalogue (UAPC) and from several individual observers. For 18 asteroids, we present updated shape solutions based on new photometric data. For another 30 asteroids we present their partial models, i.e., an accurate period value and an estimate of the ecliptic latitude of the pole. The addition of new models increases the total number of models derived by the lightcurve inversion method to ∼200. We also present a simple statistical analysis of physical properties of asteroids where we look for possible correlations between various physical parameters with an emphasis on the spin vector. We present the observed and de-biased distributions of ecliptic latitudes with respect to different size ranges of asteroids as well as a simple theoretical model of the latitude distribution and then compare its predictions with the observed distributions. From this analysis we find that the latitude distribution of small asteroids (D 60 km) exhibits an evident excess of prograde rotators, probably of primordial origin.

Journal ArticleDOI
TL;DR: In 1989, Wynn and McGrew published an explicit comparison between Oldowan technology and what was then known of chimpanzee technology, and concluded that everything archeologists had reconstructed about the behavior of Oldowan hominins could be accommodated within the ape adaptive grade.
Abstract: In 1989, Wynn and McGrew published an explicit comparison between Oldowan technology and what was then known of chimpanzee technology.1 They compared the range and variety of tools, adaptive role of tools, carrying distances, spatial cognition, manufacturing procedures, and modes of learning. They concluded that everything archeologists had reconstructed about the behavior of Oldowan hominins could be accommodated within the ape adaptive grade; that is, a paraphyletic group united by overall similarities in anatomy and, in this case, behavior. The only Oldowan activities that were almost unknown for modern apes were the long-distance transport of objects and direct competition with carnivores, which was implied by meat acquisition activities. “In its general features Oldowan culture was ape, not human. Nowhere in this picture need we posit elements such as language, extensive sharing, division of labor, or pair-bonded families, all of which are part of the baggage carried by the term human.”1:394 © 2011 Wiley-Liss, Inc.

Journal ArticleDOI
TL;DR: In this article, the authors compared numerical and experimental results for a phase change material conditioned in a parallelepipedic polyefin envelope to be used in passive solar walls.

Journal ArticleDOI
TL;DR: A new approach to hologram generation and display is presented which overcomes both of these problems, enabling-for the first time-a high-quality real-time holographic projector.
Abstract: Phase-only holographic projection has prompted a great deal of research and has often been cited as a desirable method of 2-D image formation, since such a technique offers a number of advantages over conventional imaging projection technology. Although holographic image formation was demonstrated some forty years ago, efforts at realizing a real-time 2-D video projection system based on this technique have not been successful, principally due to the computational complexity of calculating diffraction patterns in real time and the poor quality of the resultant images. In this paper, a new approach to hologram generation and display is presented which overcomes both of these problems, enabling-for the first time-a high-quality real-time holographic projector.

Journal ArticleDOI
TL;DR: Four sets of studies conducted in four different cultures and with people who have experienced different types of trauma reveal this atypical response pattern and lend support to ABDT, which posits that PTSD results from a disruption in one's anxiety-buffering mechanisms.
Abstract: We present anxiety buffer disruption theory (ABDT) and provide a review of current evidence regarding the theory. ABDT is an application of terror management theory to explain diverse reactions to traumatic events and the onset and maintenance of posttraumatic stress disorder (PTSD). It posits that PTSD results from a disruption in one's anxiety-buffering mechanisms, which normally provide protection against anxiety in general and death anxiety in particular. The disruption of these mechanisms leaves the individual defenseless in the face of overwhelming anxiety, which leads to the major symptom clusters of PTSD: re-experiencing, hyper-arousal, and avoidance. According to ABDT, because of the disruption in their anxiety-buffering mechanisms, individuals with PTSD symptoms do not respond to mortality reminders in the defensive ways that psychologically healthier individuals do. We review four sets of studies conducted in four different cultures and with people who have experienced different types of trauma, which reveal this atypical response pattern and lend support to ABDT.

Journal ArticleDOI
TL;DR: IOP fluctuates as much as 10 mm Hg from day to day and hour to hour in unrestrained nonhuman primates, which indicates that snapshot IOP measurements may be inadequate to capture the true dynamic character of IOP.
Abstract: Purpose. IOP is the most common independent risk factor for development and progression of glaucoma, but very little is known about IOP dynamics. Continuous IOP telemetry was used in three nonhuman primates to characterize IOP dynamics at multiple time scales for multiple 24-hour periods.

Journal ArticleDOI
01 Aug 2011-Icarus
TL;DR: In this paper, the authors used the lightcurve inversion method to predict the orientation of an asteroid for the time of an occultation by scaling the shape model to fit the occultation chords, which can determine the asteroid size with a relative accuracy of typically ∼10%.

Journal ArticleDOI
TL;DR: A series of cellulose esters with high degrees of substitution has been obtained by linking aliphatic acid chlorides (from C8 to C18) onto cellulose backbone, in a homogeneous LiCl/DMAc medium.

Journal ArticleDOI
TL;DR: In this paper, the status of current efforts to assimilate cloud and precipitation-affected satellite data is summarised with special focus on infrared and microwave radiance data obtained from operational Earth observation satellites.
Abstract: The status of current efforts to assimilate cloud- and precipitation-affected satellite data is summarised with special focus on infrared and microwave radiance data obtained from operational Earth observation satellites. All global centres pursue efforts to enhance infrared radiance data usage due to the limited availability of temperature observations in cloudy regions where forecast skill is estimated to strongly depend on the initial conditions. Most systems focus on the sharpening of weighting functions at cloud top providing high vertical resolution temperature increments to the analysis, mainly in areas of persistent high and low cloud cover. Microwave radiance assimilation produces impact on the deeper atmospheric moisture structures as well as cloud microphysics and, through control variable and background-error formulation, also on temperature but to lesser extent than infrared data. Examples of how the impacts of these two observation types are combined are shown for subtropical low-level cloud regimes. The overall impact of assimilating such data on forecast skill is measurably positive despite the fact that the employed assimilation systems have been constructed and optimized for clear-sky data. This leads to the conclusion that a better understanding and modelling of model processes in cloud-affected areas and data assimilation system enhancements through inclusion of moist processes and their error characterization will contribute substantially to future forecast improvement. Copyright © 2011 Royal Meteorological Society, Crown in the right of Canada, and British Crown copyright, the Met Office

Journal ArticleDOI
TL;DR: In this article, the authors present a model and empirical test that supplier-to-buyer identification fosters superior operational performance by enhancing trust, supplier relation-specific investments, and information exchange.

Journal ArticleDOI
TL;DR: Park et al. as discussed by the authors performed a numerical simulation of the effect of the dissolution of LiMn2O4 particles on Li-Ion battery performance and found that dissolution significantly reduced battery performance.
Abstract: Numerical Simulation of the Effect of the Dissolution of LiMn2O4 Particles on Li-Ion Battery Performance Jonghyun Park, Jeong Hun Seo, Gregory Plett,* Wei Lu, and Ann Marie Sastry Department of Mechanical Engineering, Department of Biomedical Engineering, and Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2125, USA Department of Electrical and Computer Engineering, University of Colorado at Colorado Springs, Colorado Springs, Colorado 80933-7150, USA

Journal ArticleDOI
TL;DR: The authors applied direct consensus or referent-shift consensus composition models when aggregating individual-level data to a higher level of analysis, and found that direct consensus is more accurate than referent shift consensus composition.
Abstract: Multilevel researchers have predominantly applied either direct consensus or referent-shift consensus composition models when aggregating individual-level data to a higher level of analysis. This p...

Journal ArticleDOI
TL;DR: A pulsed Raman laser at 1193 nm based on synthetic diamond crystals with a record output power of 24.5 W and a slope efficiency of 57%.
Abstract: We report a pulsed Raman laser at 1193 nm based on synthetic diamond crystals with a record output power of 24.5 W and a slope efficiency of 57%. We compared the performance of an anti-reflection coated crystal at normal incidence with a Brewster cut sample. Raman oscillation was achieved at both room temperature and under cryogenic operation at 77 K. Modeling of these experiments allowed us to confirm the value of Raman gain coefficient of diamond, which was found to be 13.5 ± 2.0 cm/GW for a pump wavelength of 1030 nm.

Journal ArticleDOI
TL;DR: In this paper, the inhibition properties of 2,5-bis( n -pyridyl)-1,3,4-thiadiazoles (n -PTH) on corrosion of mild steel in different acidic media were analyzed by electrochemical impedance spectroscopy (EIS).

BookDOI
31 May 2011
TL;DR: System Health Management: with Aerospace Applications provides the first complete reference text for System Health Management (SHM), the set of technologies and processes used to improve system dependability.
Abstract: System Health Management: with Aerospace Applications provides the first complete reference text for System Health Management (SHM), the set of technologies and processes used to improve system dependability. Edited by a team of engineers and consultants with SHM design, development, and research experience from NASA, industry, and academia, each heading up sections in their own areas of expertise and co-coordinating contributions from leading experts, the book collates together in one text the state-of-the-art in SHM research, technology, and applications. It has been written primarily as a reference text for practitioners, for those in related disciplines, and for graduate students in aerospace or systems engineering.