scispace - formally typeset
Search or ask a question

Showing papers by "Worcester Polytechnic Institute published in 2014"


Journal ArticleDOI
TL;DR: Conclusions are drawn showing that numerous possibilities and insights can be gained from expanding the types of tools and factors considered in formal modeling efforts.

946 citations


Journal ArticleDOI
TL;DR: The authors compared variation in the replicability of 13 classic and contemporary effects across 36 independent samples totaling 6,344 participants and found that the results of these experiments are more dependent on the effect itself than on the sample and setting used to investigate the effect.
Abstract: Although replication is a central tenet of science, direct replications are rare in psychology. This research tested variation in the replicability of 13 classic and contemporary effects across 36 independent samples totaling 6,344 participants. In the aggregate, 10 effects replicated consistently. One effect – imagined contact reducing prejudice – showed weak support for replicability. And two effects – flag priming influencing conservatism and currency priming influencing system justification – did not replicate. We compared whether the conditions such as lab versus online or US versus international sample predicted effect magnitudes. By and large they did not. The results of this small sample of effects suggest that replicability is more dependent on the effect itself than on the sample and setting used to investigate the effect.

767 citations


Journal ArticleDOI
TL;DR: In this article, the authors address several issues related to the use of data envelopment analysis (DEA), including model orientation, input and output selection/definition, use of mixed and raw data, and number of inputs and outputs to use versus the number of DMUs.
Abstract: In this paper, we address several issues related to the use of data envelopment analysis (DEA). These issues include model orientation, input and output selection/definition, the use of mixed and raw data, and the number of inputs and outputs to use versus the number of decision making units (DMUs). We believe that within the DEA community, researchers, practitioners, and reviewers may have concerns and, in many cases, incorrect views about these issues. Some of the concerns stem from what is perceived as being the purpose of the DEA exercise. While the DEA frontier can rightly be viewed as a production frontier, it must be remembered that ultimately DEA is a method for performance evaluation and benchmarking against best-practice. DEA can be viewed as a tool for multiple-criteria evaluation problems where DMUs are alternatives and each DMU is represented by its performance in multiple criteria which are coined/classified as DEA inputs and outputs. The purpose of this paper is to offer some clarification and direction on these matters.

654 citations


Journal ArticleDOI
TL;DR: In this article, a state-of-the-art review of green roofs emphasizing current implementations, technologies, and benefits is presented in order to show how green roofs may contribute to more sustainable buildings and cities.

580 citations


Journal ArticleDOI
TL;DR: Imaging of U87 cells, a human brain glioma cancer cell line, can be easily achieved with high resolution using the prepared carbon dots as probes and validates their use in imaging applications.
Abstract: In the present work, a completely green synthetic method for producing fluorescent nitrogen-doped carbon dots by using milk is introduced. The process is environmentally friendly, simple, and efficient. By hydrothermal heating of milk, we produced monodispersed, highly fluorescent carbon dots with a size of about 3 nm. Imaging of U87 cells, a human brain glioma cancer cell line, can be easily achieved with high resolution using the prepared carbon dots as probes and validates their use in imaging applications.

461 citations


Proceedings ArticleDOI
29 Sep 2014
TL;DR: A telerobotics research platform that provides complete access to all levels of control via open-source electronics and software, and is currently installed at 11 research institutions, with additional installations underway, thereby creating a research community around a commonopen-source hardware and software platform.
Abstract: We present a telerobotics research platform that provides complete access to all levels of control via open- source electronics and software. The electronics employs an FPGA to enable a centralized computation and distributed I/O architecture in which all control computations are implemented in a familiar development environment (Linux PC) and low- latency I/O is performed over an IEEE-1394a (FireWire) bus at speeds up to 400 Mbits/sec. The mechanical components are obtained from retired first-generation da Vinci R Surgical Systems. This system is currently installed at 11 research institutions, with additional installations underway, thereby creating a research community around a common open-source hardware and software platform.

439 citations


Journal ArticleDOI
TL;DR: In this paper, the authors explored and increased understanding of critical factors that help to overcome the complexities and unique challenges of sub-supplier management, with a focus on the food industry.

375 citations


Journal ArticleDOI
TL;DR: In this paper, the authors present results from experimental studies and techno-economic analysis of a catalytic process for the conversion of whole biomass into drop-in aviation fuels with maximal carbon yields.
Abstract: This article presents results from experimental studies and techno-economic analysis of a catalytic process for the conversion of whole biomass into drop-in aviation fuels with maximal carbon yields. The combined research areas highlighted include biomass pretreatment, carbohydrate hydrolysis and dehydration, and catalytic upgrading of platform chemicals. The technology centers on first producing furfural and levulinic acid from five- and six-carbon sugars present in hardwoods and subsequently upgrading these two platforms into a mixture of branched, linear, and cyclic alkanes of molecular weight ranges appropriate for use in the aviation sector. Maximum selectivities observed in laboratory studies suggest that, with efficient interstage separations and product recovery, hemicellulose sugars can be incorporated into aviation fuels at roughly 80% carbon yield, while carbon yields to aviation fuels from cellulose-based sugars are on the order of 50%. The use of lignocellulose-derived feedstocks rather than commercially sourced model compounds in process integration provided important insights into the effects of impurity carryover and additionally highlights the need for stable catalytic materials for aqueous phase processing, efficient interstage separations, and intensified processing strategies. In its current state, the proposed technology is expected to deliver jet fuel-range liquid hydrocarbons for a minimum selling price of $4.75 per gallon assuming nth commercial plant that produces 38 million gallons liquid fuels per year with a net present value of the 20 year biorefinery set to zero. Future improvements in this technology, including replacing precious metal catalysts by base metal catalysts and improving the recyclability of water streams, can reduce this cost to $2.88 per gallon.

347 citations


Journal ArticleDOI
TL;DR: In this article, a low temperature methodology was proposed to separate and synthesize cathode materials from mixed cathode material, and the precipitated product can then be reacted with lithium carbonate to form LiNi x Mn y Co z O 2.

327 citations


Journal ArticleDOI
TL;DR: Why ASSISTments has been successful and what lessons were learned are shared and goals for the future will be presented.
Abstract: The ASSISTments project is an ecosystem of a few hundred teachers, a platform, and researchers working together. Development professionals help train teachers and get teachers to participate in studies. The platform and these teachers help researchers (sometimes explicitly and sometimes implicitly) simply by using content the teacher selects. The platform, hosted by Worcester Polytechnic Institute, allows teachers to write individual ASSISTments (composed of questions with answers and associated hints, solutions, web-based videos, etc.) or to use pre-built ASSISTments, bundle them together in a problem set, and assign these to students. The system gives immediate feedback to students while they are working and provides student-level data to teachers on any assignment. The word “ASSISTments” blends tutoring “assistance” with “assessment” reporting to teachers and students. While originally focused on mathematics, the platform now has content from many other subjects (e.g., science, English, Statistics, etc.). Due to the large library of mathematics content, however, it is mostly used by math teachers. Over 50,000 students used ASSISTments last school year (2013–4) and this number has been doubling each year for the last 8 years. The platform allows any user, mostly researchers, to create randomized controlled trials in the content, which has helped us use the tool in over 18 published and an equal number of unpublished studies. The data collected by the system has also been used in a few dozen peer-reviewed data mining publications. This paper will not seek to review these publications, but instead we will share why ASSISTments has been successful and what lessons were learned along the way. The first lesson learned was to build a platform for learning sciences, not a product that focused on a math topic. That is, ASSISTments is a tool, not a curriculum. A second lesson learned is expressed by the mantra “Put the teacher in charge, not the computer.” This second lesson is about building a flexible system that allows teachers to use the tool in concert with the classroom routine. Once teachers are using the tool they are more likely to want to participate in research studies. These lessons were born from the design decisions about what the platform supports and does not support. In conclusion, goals for the future will be presented.

325 citations


Journal ArticleDOI
TL;DR: In this article, the authors present a multidimensional framework which can serve as a tool for research scholars and supply chain prac... to assist focal companies in the development of sustainable supply chains.
Abstract: Purpose – This paper aims to provide a framework which can assist focal companies in the development of sustainable supply chains. Sustainable development from an industrial perspective has extended beyond organisational boundaries to incorporate a supply chain approach. Design/methodology/approach – The literature related to sustainable supply chain management is reviewed by incorporating concepts from four organisational theories, including the resource-based, institutional, stakeholder and social network perspectives, to illustrate key drivers and enablers of sustainability initiatives in the supply chain. A conceptual multidimensional framework is then developed that can be used for the initial assessment of supply chain sustainability. Findings – Development and assessment of sustainability in supply chains are being increasingly incorporated as part of supply chain management today. This paper presents a multidimensional framework which can serve as a tool for research scholars and supply chain prac...

Journal ArticleDOI
TL;DR: In this article, 100% recycled hot mix asphalt lab samples were modified with five generic and one proprietary rejuvenators at 12% dose and tested for binder and mixture properties, which ensured excellent rutting resistance while providing longer fatigue life compared to virgin mixtures and most lowered critical cracking temperature.

Journal ArticleDOI
22 Oct 2014-Neuron
TL;DR: In this paper, an exome-wide rare variant burden analysis of 363 index cases with familial ALS (FALS) was performed and the results revealed an excess of patient variants within TUBA4A, the gene encoding the Tubulin, Alpha 4A protein.

Journal ArticleDOI
TL;DR: A holistic evaluation of the feasibility of producing 100% recycled asphalt pavement mixtures is presented in this article, where a cradle-to-gate analysis of environmental effects indicated 18 kg or 35% CO2eq savings per t of produced 100% RAP asphalt mixture compared to virgin mix, while cost analysis showed at least 50% savings in material related expenses.
Abstract: a b s t r a c t A holistic evaluation of the feasibility of producing 100% recycled mixtures is presented. Eleven tech- nologies readily available for producing 100% Reclaimed Asphalt Pavement (RAP) hot asphalt mixtures are described in the article and the complementary video (http://youtu.be/coj-e5mhHEQ). The recorded performance of 100% RAP mixtures is analyzed along with identification of typical high RAP distresses. Recommended mix design procedures and the best RAP management strategies are described. A cradle- to-gate analysis of environmental effects indicated 18 kg or 35% CO2eq savings per t of produced 100% RAP asphalt mixture compared to virgin mix, while cost analysis showed at least 50% savings in material related expenses.

Journal ArticleDOI
11 Mar 2014-JOM
TL;DR: Additive manufacturing (AM) refers to an advanced technology used for the fabrication of three-dimensional near-net-shaped functional components directly from computer models, using unit materials.
Abstract: Additive manufacturing (AM) refers to an advanced technology used for the fabrication of three-dimensional near-net-shaped functional components directly from computer models, using unit materials. The fundamentals and working principle of AM offer several advantages, including near-net-shape capabilities, superior design and geometrical flexibility, innovative multi-material fabrication, reduced tooling and fixturing, shorter cycle time for design and manufacturing, instant local production at a global scale, and material, energy, and cost efficiency. Well suiting the requests of modern manufacturing climate, AM is viewed as the new industrial revolution, making its way into a continuously increasing number of industries, such as aerospace, defense, automotive, medical, architecture, art, jewelry, and food. This overview was created to relate the historical evolution of the AM technology to its state-of-the-art developments and emerging applications. Generic thoughts on the microstructural characteristics, properties, and performance of AM-fabricated materials will also be discussed, primarily related to metallic materials. This write-up will introduce the general reader to specifics of the AM field vis-a-vis advantages and common techniques, materials and properties, current applications, and future opportunities.

Book ChapterDOI
17 Sep 2014
TL;DR: In this article, a cache-based attack on OpenSSL AES implementation running on VMware VMs is presented, which takes only in the order of seconds to minutes to succeed in a cross-VM setting.
Abstract: In cloud computing, efficiencies are reaped by resource sharing such as co-location of computation and deduplication of data. This work exploits resource sharing in virtualization software to build a powerful cache-based attack on AES. We demonstrate the vulnerability by mounting Cross-VM Flush+Reload cache attacks in VMware VMs to recover the keys of an AES implementation of OpenSSL 1.0.1 running inside the victim VM. Furthermore, the attack works in a realistic setting where different VMs are located on separate cores. The modified flush+reload attack we present, takes only in the order of seconds to minutes to succeed in a cross-VM setting. Therefore long term co-location, as required by other fine grain attacks in the literature, are not needed. The results of this study show that there is a great security risk to OpenSSL AES implementation running on VMware cloud services when the deduplication is not disabled.

Journal ArticleDOI
01 Nov 2014-Fuel
TL;DR: In this paper, two different asphalt binders from the Materials Reference Library of the Strategic Highway Research Program (SHRP) were aged, and rejuvenated by complete blending with two commonly used rejuvenators.

Book
01 May 2014
TL;DR: This book provides an introduction to the field with a focus on the unique technical challenges associated with designing robots that learn from naive human teachers, and provides best practices for evaluation of LfD systems.
Abstract: Learning from Demonstration (LfD) explores techniques for learning a task policy from examples provided by a human teacher The field of LfD has grown into an extensive body of literature over the past 30 years, with a wide variety of approaches for encoding human demonstrations and modeling skills and tasks Additionally, we have recently seen a focus on gathering data from non-expert human teachers (ie, domain experts but not robotics experts) In this book, we provide an introduction to the field with a focus on the unique technical challenges associated with designing robots that learn from naive human teachers We begin, in the introduction, with a unification of the various terminology seen in the literature as well as an outline of the design choices one has in designing an LfD system Chapter 2 gives a brief survey of the psychology literature that provides insights from human social learning that are relevant to designing robotic social learners Chapter 3 walks through an LfD interaction, surveying the design choices one makes and state of the art approaches in prior work First, is the choice of input, how the human teacher interacts with the robot to provide demonstrations Next, is the choice of modeling technique Currently, there is a dichotomy in the field between approaches that model low-level motor skills and those that model high-level tasks composed of primitive actions We devote a chapter to each of these Chapter 7 is devoted to interactive and active learning approaches that allow the robot to refine an existing task model And finally, Chapter 8 provides best practices for evaluation of LfD systems, with a focus on how to approach experiments with human subjects in this domain

01 Jan 2014
TL;DR: A holistic evaluation of the feasibility of producing 100% recycled asphalt pavement (RAP) mixtures is presented in this paper, where a cradle-to-gate analysis of environmental effects indicated 18 kg or 35% CO2eq savings per t of produced 100% RAP asphalt mixture compared to virgin mix, while cost analysis showed at least 50% savings in material related expenses.
Abstract: a b s t r a c t A holistic evaluation of the feasibility of producing 100% recycled mixtures is presented Eleven tech- nologies readily available for producing 100% Reclaimed Asphalt Pavement (RAP) hot asphalt mixtures are described in the article and the complementary video (http://youtube/coj-e5mhHEQ) The recorded performance of 100% RAP mixtures is analyzed along with identification of typical high RAP distresses Recommended mix design procedures and the best RAP management strategies are described A cradle- to-gate analysis of environmental effects indicated 18 kg or 35% CO2eq savings per t of produced 100% RAP asphalt mixture compared to virgin mix, while cost analysis showed at least 50% savings in material related expenses

01 Jan 2014
TL;DR: In this paper, 100% recycled hot mix asphalt lab samples were modified with five generic and one proprietary rejuvenators at 12% dose and tested for binder and mixture properties, which ensured excellent rutting resistance while providing longer fatigue life compared to virgin mixtures and most lowered critical cracking temperature.
Abstract: 100% recycled hot mix asphalt lab samples were modified with five generic and one proprietary rejuvenators at 12% dose and tested for binder and mixture properties. Waste Vegetable Oil, Waste Vegetable Grease, Organic Oil, Distilled Tall Oil, and Aromatic Extract reduced the Superpave performance grade (PG) from 94–12 of extracted binder to PG 64-22 while waste engine oil required higher dose. All products ensured excellent rutting resistance while providing longer fatigue life when compared to virgin mixtures and most lowered critical cracking temperature. Rejuvenated samples required more compaction energy compared to virgin and some oils reduced moisture resistance slightly.

Posted Content
TL;DR: The results of this study show that there is a great security risk to OpenSSL AES implementation running on VMware cloud services when the deduplication is not disabled.
Abstract: In cloud computing, efficiencies are reaped by resource sharing such as co-location of computation and deduplication of data. This work exploits resource sharing in virtualization software to build a powerful cache-based attack on AES. We demonstrate the vulnerability by mounting Cross-VM Flush+Reload cache attacks in VMware VMs to recover the keys of an AES implementation of OpenSSL 1.0.1 running inside the victim VM. Furthermore, the attack works in a realistic setting where different VMs are located on separate cores. The modified flush+reload attack we present, takes only in the order of seconds to minutes to succeed in a cross-VM setting. Therefore long term co-location, as required by other fine grain attacks in the literature, are not needed. The results of this study show that there is a great security risk to OpenSSL AES implementation running on VMware cloud services when the deduplication is not disabled.

Journal ArticleDOI
TL;DR: In this article, a two-stage method utilizing neighborhood rough set theory to identify sustainable supply chain key performance indicators (KPI) and data envelopment analysis (DEA) to benchmark and evaluate relative performance using the KPI is completed.
Abstract: Purpose – The purpose of this paper is to introduce a methodology to identify sustainable supply chain key performance indicators (KPI) that can then be used for sustainability performance evaluation for suppliers. Design/methodology/approach – Initially the complexity of sustainable supply chain performance measurement is discussed. Then, a two-stage method utilizing neighborhood rough set theory to identify KPI and data envelopment analysis (DEA) to benchmark and evaluate relative performance using the KPI is completed. Additional analysis is performed to determine the sensitivity of the KPI set formation and performance results. Findings – The results show that KPI can be determined using neighborhood rough set, and DEA performance results provide insight into relative performance of suppliers. The supply chain sustainability performance results from both the neighborhood rough set and DEA can be quite sensitive parameters selected and sustainability KPI sets that were determined. Research limitations/...

Proceedings ArticleDOI
29 Sep 2014
TL;DR: Results with a robot consisting of six segments show that controlled movement of a soft and highly compliant manipulator is feasible and algorithms to compute the arm's forward and inverse kinematics in a manner consistent with piece-wise constant curvature continuum manipulators are developed.
Abstract: In this paper we describe the design, fabrication, control, and experimental validation of a soft and highly compliant 2D manipulator. The arm consists of several body segments actuated using bi-directional fluidic elastomer actuators and is fabricated using a novel composite molding process. We use a cascaded PI and PID computation and novel fluidic drive cylinders to provide closed-loop control of curvature for each soft and highly compliant body segment. Furthermore, we develop algorithms to compute the arm’s forward and inverse kinematics in a manner consistent with piece-wise constant curvature continuum manipulators. These computation and control systems enable this highly compliant robot to autonomously follow trajectories. Experimental results with a robot consisting of six segments show that controlled movement of a soft and highly compliant manipulator is feasible.

Journal ArticleDOI
TL;DR: The current paper uses the cross-efficiency concept in DEA to approach cost and resource allocation problems, and shows that the proposed iterative approach is always feasible, and ensures that all DMUs become efficient after the fixed cost is allocated as an additional input measure.

Journal ArticleDOI
TL;DR: It is found that composition and crystalline structure of the tin element played important roles in the CO2 generation: non-alloyed Pt46-(SnO2)54 core-shell particles demonstrated a strong capability for C-C bond breaking of ethanol than pure Pt and intermetallic Pt/Sn, showing 4.1 times higher CO2 peak partial pressure generated from EOR than commercial Pt/C.
Abstract: Platinum-tin (Pt/Sn) binary nanoparticles are active electrocatalysts for the ethanol oxidation reaction (EOR), but inactive for splitting the C-C bond of ethanol to CO2. Here we studied detailed structure properties of Pt/Sn catalysts for the EOR, especially CO2 generation in situ using a CO2 microelectrode. We found that composition and crystalline structure of the tin element played important roles in the CO2 generation: non-alloyed Pt46-(SnO2)54 core-shell particles demonstrated a strong capability for C-C bond breaking of ethanol than pure Pt and intermetallic Pt/Sn, showing 4.1 times higher CO2 peak partial pressure generated from EOR than commercial Pt/C.

Journal ArticleDOI
15 Oct 2014-Fuel
TL;DR: In this article, the influence of synthesis factors, including chemical composition of raw materials and curing conditions, on the microstructure and mechanical properties of geopolymers synthesized from red mud (RM) and class F fly ash (FFA) was investigated.

Journal ArticleDOI
TL;DR: A suite of effective strategies to support advanced personalized learning via an intelligent adaptive tutor that can be tailored to the individual needs, emotions, cognitive states, and metacognitive skills of learners are elucidated.
Abstract: This article describes research results based on multiple years of experimentation and real-world experience with an adaptive tutoring system named Wayang Outpost. The system represents a novel adaptive learning technology that has shown successful outcomes with thousands of students, and provided teachers with valuable information about students’ mathematics performance. We define progress in three areas: improved student cognition, engagement, and affect, and we attribute this improvement to specific components and interventions that are inherently affective, cognitive, and metacognitive in nature. For instance, improved student cognitive outcomes have been measured with pre-post tests and state standardized tests, and achieved due to personalization of content and math fluency training. Improved student engagement was achieved by supporting students’ metacognition and motivation via affective learning companions and progress reports, measured via records of student gaming of the system. Student affect within the tutor was measured through sensors and student self-reports, and supported through affective learning companions and progress reports. Collectively, these studies elucidate a suite of effective strategies to support advanced personalized learning via an intelligent adaptive tutor that can be tailored to the individual needs, emotions, cognitive states, and metacognitive skills of learners.

Journal ArticleDOI
TL;DR: The proposed approach to DEA cross-efficiency evaluation in portfolio selection can be a promising tool for stock portfolio selection by showing that the selected portfolio yields higher risk-adjusted returns than other benchmark portfolios for a 9-year sample period from 2002 to 2011.

Journal ArticleDOI
TL;DR: In this article, the authors provide a brief introduction on magnetic iron oxide nanoparticles in terms of their fundamentals of magnetism, magnetic resonance imaging (MRI), and drug delivery, as well as the synthesis approaches, surface coating, and application examples from recent key literatures.
Abstract: Iron oxide nanoparticles are the most popular magnetic nanoparticles used in biomedical applications due to their low cost, low toxicity, and unique magnetic property. Magnetic iron oxide nanoparticles, including magnetite (Fe3O4) and maghemite (?-Fe2O3), usually exhibit a superparamagnetic property as their size goes smaller than 20 nm, which are often denoted as superparamagnetic iron oxide nanoparticles (SPIONs) and utilized for drug delivery, diagnosis, therapy, and etc. This review article gives a brief introduction on magnetic iron oxide nanoparticles in terms of their fundamentals of magnetism, magnetic resonance imaging (MRI), and drug delivery, as well as the synthesis approaches, surface coating, and application examples from recent key literatures. Because the quality and surface chemistry play important roles in biomedical applications, our review focuses on the synthesis approaches and surface modifications of iron oxide nanoparticles. We aim to provide a detailed introduction to readers who are new to this field, helping them to choose suitable synthesis methods and to optimize the surface chemistry of iron oxide nanoparticles for their interests.

Journal ArticleDOI
TL;DR: This paper investigated the correspondence between student affect and behavioural engagement in a web-based tutoring platform throughout the school year and learning outcomes at the end of the year on a high-stakes mathematics exam in a manner that is both longitudinal and fine-grained.
Abstract: In this paper, we investigate the correspondence between student affect and behavioural engagement in a web-based tutoring platform throughout the school year and learning outcomes at the end of the year on a high-stakes mathematics exam in a manner that is both longitudinal and fine-grained. Affect and behaviour detectors are used to estimate student affective states and behaviour based on post-hoc analysis of tutor log-data. For every student action in the tutor, the detectors give us an estimated probability that the student is in a state of boredom, engaged concentration, confusion, or frustration, and estimates of the probability that the student is exhibiting off-task or gaming behaviours. We used data from the ASSISTments math tutoring system and found that boredom during problem solving is negatively correlated with performance, as expected; however, boredom is positively correlated with performance when exhibited during scaffolded tutoring. A similar pattern is unexpectedly seen for confusion. Engaged concentration and, surprisingly, frustration are both associated with positive learning outcomes. In a second analysis, we build a unified model that predicts student standardized examination scores from a combination of student affect, disengaged behaviour, and performance within the learning system. This model achieves high overall correlation to standardized exam score, showing that these types of features can effectively infer longer-term learning outcomes.