bluuebunny/crossref_metadata_2025 huggingface dataset:
Biomechanical analysis of the cancellous screws implantation schemes in surgical treatment of flexible flatfoot in children
Authors: Koshman Gennadiy , Barsukov Vladimir , Anosov Viktor , Pauk Jolanta
Published: November 2016

Carry out comparative biomechanical analysis of influence of the implantation scheme
and characteristic sizes of cancellous screws on parameters of its strained condition, and elaborate
guidelines for optimization of implantation parameters and decision for a material metalware
choice. Performed mathematical modelling and comparative numerical analysis of the parameters
of strained condition, slant and cantilevered schemes of implantation of cancellous screws, applied
to a wide range of support loads variations acting on a screw. Made analysis of influence of size
parameters (length of the overhanging part, angle with normal at supporting surface, core
diameter) on the magnitude of the calculated stress that appear in compressed and extended zones
of slant implanted screw. Carried out investigations reveal that short screws, installed on the hard
circuit, from the standpoint of operational reliability according to the criteria of strength under
static loading (occasional overload) and multicyclic loading have the highest capacity for work.
Least favourable in application are slant and cantilevered implanted screws. With increasing
length of cantilevered part and angle between axis of a screw and line of loading force calculated
values of stress also increases. Screws of heat-treated stainless steel are preferred from the
standpoint of saving bearing capacity with unit congestion due to increased plasticity in 4–5 times
(residual strain at failure) compared with titanium alloys.
Posturographic study of human body sway before and after a work day for diagnosis of tiredness
Authors: Karpinski Michail , Kizilova Natalya
Published: November 2016

Body sway measured by force platform is an excellent simple test for diagnostics of
locomotory, balance, visual and neural disorders. In this study the body sway parameters have
been measured on a group of healthy medical workers in the morning/evening time before/after
their work day. The centre of pressure (CoP) trajectories in a series of different 2-leg stances and
during a step forward off from the force platform have been recorded. It was found, in the morning
the sway amplitudes were higher due to relaxed state of muscles, while after the work day the
muscles were tired and the force platform test demanded more attention and body control which
mostly lead to lower body sway amplitudes. The step off from the platform were executed faster
in the evening, and the more elderly individuals exhibited more pronounced pathological signs in
the CoP trajectory in the evening. Basing on the data analysis, new indices of tiredness and stress
level are proposed for occupational medicine.
Graduate skills requirements for effective performance in the banking sector
Authors: Cicekli Elif
Published: November 2016

This paper aimed to explore the graduate skills requirements in the banking sector. In-depth interviews were carried out with twenty-five managers in ten companies in the banking industry in Turkey. The results show that 40 percent of managers thought universities do not provide their graduates with the skills necessary to be successful in their jobs. Soft skills (i.e. communication, interpersonal relationship, and teamwork skills) are particularly sought after, and managers would also like to see more training in analytical thinking skills. Researchers are recommended to study the subject in different counties using quantitative methods. Based on results, bank executives are advised to communicate and collaborate with educators to make sure their needs are known and met. This paper filled the gap in research on the skills the banking sector needs in new graduates.
Valuing start-ups – selected approaches and their modification based on external factors
Authors: Skalicka Dusatkova Martina , Zinecker Marek
Published: November 2016

The recent methods of start-up valuation seek to compensate for the lack of data necessary for a standard company valuation with additional information on the person of the entrepreneur and business project. None of the existing approaches, however, takes into consideration information about the environment in which the venture capitalists conduct their investments. Therefore, the aim of this paper is to develop an approach considering factors of the investee companies’ environment. Such a modification will allow a more accurate estimate of the value of the projects investigated. The nature of this study is explorative. It relies on secondary data that was collected using interviews and semi-structured questionnaires in previous empirical studies. During the course of the modelling process, information on the quality of the investee companies’ environment expressed is incorporated into the established start-up project valuations. Our original proposal consists of the modification of the β coefficient calculation for a given type of projects. An essential part of this modification is also a proposal for the extension of the project scoring characteristics to include expert estimates and, in the case of regression analysis, the inclusion of explanatory variables expressing the suitability of the environment for venture capital investments.
SPARC: MASS MODELS FOR 175 DISK GALAXIES WITH SPITZER PHOTOMETRY AND ACCURATE ROTATION CURVES
Authors: Lelli Federico , McGaugh Stacy S. , Schombert James M.
Published: November 2016

We introduce SPARC (Spitzer Photometry and Accurate Rotation Curves): a sample of 175 nearby galaxies with new surface photometry at 3.6 μm and high-quality rotation curves from previous H i/Hα studies. SPARC spans a broad range of morphologies (S0 to Irr), luminosities (∼5 dex), and surface brightnesses (∼4 dex). We derive [3.6] surface photometry and study structural relations of stellar and gas disks. We find that both the stellar mass–H i mass relation and the stellar radius–H i radius relation have significant intrinsic scatter, while the H i   mass–radius relation is extremely tight. We build detailed mass models and quantify the ratio of baryonic to observed velocity (V
bar/V
obs) for different characteristic radii and values of the stellar mass-to-light ratio (ϒ⋆) at [3.6]. Assuming ϒ⋆ ≃ 0.5 M
⊙/L
⊙ (as suggested by stellar population models), we find that (i) the gas fraction linearly correlates with total luminosity; (ii) the transition from star-dominated to gas-dominated galaxies roughly corresponds to the transition from spiral galaxies to dwarf irregulars, in line with density wave theory; and (iii) V
bar/V
obs varies with luminosity and surface brightness: high-mass, high-surface-brightness galaxies are nearly maximal, while low-mass, low-surface-brightness galaxies are submaximal. These basic properties are lost for low values of ϒ⋆ ≃ 0.2 M
⊙/L
⊙ as suggested by the DiskMass survey. The mean maximum-disk limit in bright galaxies is ϒ⋆ ≃ 0.7 M
⊙/L
⊙ at [3.6]. The SPARC data are publicly available and represent an ideal test bed for models of galaxy formation.
DETECTION OF POTENTIAL TRANSIT SIGNALS IN 17 QUARTERS OF KEPLER DATA: RESULTS OF THE FINAL KEPLER MISSION TRANSITING PLANET SEARCH (DR25)
Authors: Twicken Joseph D. , Jenkins Jon M. , Seader Shawn E. , Tenenbaum Peter , Smith Jeffrey C. , Brownston Lee S. , Burke Christopher J. , Catanzarite Joseph H. , Clarke Bruce D. , Cote Miles T. , Girouard Forrest R. , Klaus Todd C. , Li Jie , McCauliff Sean D. , Morris Robert L. , Wohler Bill , Campbell Jennifer R. , Uddin Akm Kamal , Zamudio Khadeejah A. , Sabale Anima , Bryson Steven T. , Caldwell Douglas A. , Christiansen Jessie L. , Coughlin Jeffrey L. , Haas Michael R. , Henze Christopher E. , Sanderfer Dwight T. , Thompson Susan E.
Published: November 2016

We present results of the final Kepler Data Processing Pipeline search for transiting planet signals in the full 17-quarter primary mission data set. The search includes a total of 198,709 stellar targets, of which 112,046 were observed in all 17 quarters and 86,663 in fewer than 17 quarters. We report on 17,230 targets for which at least one transit signature is identified that meets the specified detection criteria: periodicity, minimum of three observed transit events, detection statistic (i.e., signal-to-noise ratio) in excess of the search threshold, and passing grade on three statistical transit consistency tests. Light curves for which a transit signal is identified are iteratively searched for additional signatures after a limb-darkened transiting planet model is fitted to the data and transit events are removed. The search for additional planets adds 16,802 transit signals for a total of 34,032; this far exceeds the number of transit signatures identified in prior pipeline runs. There was a strategic emphasis on completeness over reliability for the final Kepler transit search. A comparison of the transit signals against a set of 3402 well-established, high-quality Kepler Objects of Interest yields a recovery rate of 99.8%. The high recovery rate must be weighed against a large number of false-alarm detections. We examine characteristics of the planet population implied by the transiting planet model fits with an emphasis on detections that would represent small planets orbiting in the habitable zone of their host stars.
BRIGHT HOT IMPACTS BY ERUPTED FRAGMENTS FALLING BACK ON THE SUN: MAGNETIC CHANNELLING
Authors: Petralia A. , Reale F. , Orlando S. , Testa P.
Published: November 2016

Dense plasma fragments were observed to fall back on the solar surface by the Solar Dynamics Observatory after an eruption on 2011 June 7, producing strong extreme-ultraviolet brightenings. Previous studies investigated impacts in regions of weak magnetic field. Here we model the

km s−1 impact of fragments channelled by the magnetic field close to active regions. In the observations, the magnetic channel brightens before the fragment impact. We use a 3D-MHD model of spherical blobs downfalling in a magnetized atmosphere. The blob parameters are constrained from the observation. We run numerical simulations with different ambient densitie and magnetic field intensities. We compare the model emission in the 171 Å channel of the Atmospheric Imaging Assembly with the observed one. We find that a model of downfall channelled in an ∼1 MK coronal loop confined by a magnetic field of ∼10–20 G, best explains qualitatively and quantitatively the observed evolution. The blobs are highly deformed and further fragmented when the ram pressure becomes comparable to the local magnetic pressure, and they are deviated to be channelled by the field because of the differential stress applied by the perturbed magnetic field. Ahead of them, in the relatively dense coronal medium, shock fronts propagate, heat, and brighten the channel between the cold falling plasma and the solar surface. This study shows a new mechanism that brightens downflows channelled by the magnetic field, such as in accreting young stars, and also works as a probe of the ambient atmosphere, providing information about the local plasma density and magnetic field.
MULTI-WAVELENGTH POLARIMETRY AND SPECTRAL STUDY OF THE M87 JET DURING 2002–2008*
Authors: Avachat Sayali S. , Perlman Eric S. , Adams Steven C. , Cara Mihai , Owen Frazer , Sparks William B. , Georganopoulos Markos
Published: November 2016

We present a multi-wavelength polarimetric and spectral study of the M87 jet obtained at sub-arcsecond resolution between 2002 and 2008. The observations include multi-band archival VLA polarimetry data sets along with Hubble Space Telescope (HST) imaging polarimetry. These observations have better angular resolution than previous work by factors of 2–3 and in addition, allow us to explore the time domain. These observations envelop the huge flare in HST-1 located 0.″86 from the nucleus. The increased resolution enables us to view more structure in each knot, showing several resolved sub-components. We also see apparent helical structure in the polarization vectors in several knots, with polarization vectors turning either clockwise or counterclockwise near the flux maxima in various places as well as showing filamentary undulations. Some of these characteristics are correlated with flux and polarization maxima while others are not. We also examine the total flux and fractional polarization and look for changes in both radio and optical since the observations of Perlman et al. (1999) and test them against various models based on shocks and instabilities in the jet. Our results are broadly consistent with previous spine-sheath models and recollimation shock models; however, they require additional combinations of features to explain the observed complexity, e.g., shearing of magnetic field lines near the jet surface and compression of the toroidal component near shocks. In particular, in many regions we find apparently helical features both in total flux and polarization. We discuss the physical interpretation of these features.
THE MID-INFRARED EVOLUTION OF THE FU ORIONIS DISK
Authors: Green Joel D. , Jones Olivia C. , Keller Luke D. , Poteet Charles A. , Yang Yao-Lun , Fischer William J. , Evans II Neal J. , Sargent Benjamin A. , Rebull Luisa M.
Published: November 2016

We present new SOFIA-FORCAST observations obtained in 2016 February of the archetypal outbursting low-mass young stellar object FU Orionis, and we compare the continuum, solid-state, and gas properties with mid-infrared data obtained at the same wavelengths in 2004 with Spitzer-IRS. In this study, we conduct the first mid-infrared spectroscopic comparison of an FUor over a long time period. Over a 12-year period, UBVR monitoring indicates that FU Orionis has continued its steady decrease in overall brightness by ∼14%. We find that this decrease in luminosity occurs only at wavelengths ≲20 μm. In particular, the continuum shortward of the silicate emission complex at 10 μm exhibits a ∼12% (∼3σ) drop in flux density but no apparent change in slope; both the Spitzer and SOFIA spectra are consistent with a 7200 K blackbody. Additionally, the detection of water absorption is consistent with the Spitzer spectrum. The silicate emission feature at 10 μm continues to be consistent with unprocessed grains, unchanged over 12 years. We conclude that either the accretion rate in FU Orionis has decreased by ∼12–14% over this time baseline or the inner disk has cooled, but the accretion disk remains in a superheated state outside the innermost region.
RETURN TO [Log-]NORMALCY: RETHINKING QUENCHING, THE STAR FORMATION MAIN SEQUENCE, AND PERHAPS MUCH MORE
Authors: Abramson Louis E. , Gladders Michael D. , Dressler Alan , Oemler Augustus , Poggianti Bianca , Vulcani Benedetta
Published: November 2016

Knowledge of galaxy evolution rests on cross-sectional observations of different objects at different times. Understanding of galaxy evolution rests on longitudinal interpretations of how these data relate to individual objects moving through time. The connection between the two is often assumed to be clear, but we use a simple “physics-free” model to show that it is not and that exploring its nuances can yield new insights. Comprising nothing more than 2094 loosely constrained lognormal star formation histories (SFHs), the model faithfully reproduces the following data it was not designed to match: stellar mass functions at

the slope of the star formation rate/stellar mass relation (the SFR “Main Sequence”) at

the mean

of low-mass galaxies at

“fast-” and “slow-track” quenching; downsizing; and a correlation between formation timescale and

similar to results from simulations that provides a natural connection to bulge growth. We take these findings—which suggest that quenching is the natural downturn of all SFHs affecting galaxies at rates/times correlated with their densities—to mean that: (1) models in which galaxies are diversified on Hubble timescales by something like initial conditions rival the dominant grow-and-quench framework as good descriptions of the data; or (2) absent spatial information, many metrics of galaxy evolution are too undiscriminating—if not inherently misleading—to confirm a unique explanation. We outline future tests of our model but stress that, even if ultimately incorrect, it illustrates how exploring different paradigms can aid learning and, we hope, more detailed modeling efforts.
EVIDENCE THAT MOST TYPE-1 AGNs ARE REDDENED BY DUST IN THE HOST ISM
Authors: Baron Dalya , Stern Jonathan , Poznanski Dovi , Netzer Hagai
Published: November 2016

The typical optical–UV continuum slopes observed in many type-1 active galactic nuclei (AGNs) are redder than expected from thin accretion disk (AD) models. A possible resolution to this conundrum is that many AGNs are reddened by dust along the line of sight. To explore this possibility, we stack 5000 SDSS AGNs with luminosity

and redshift

in bins of optical continuum slope

and width of the broad Hβ emission line. We measure the equivalent width (EW) of the NaID absorption feature in each stacked spectrum. We find a linear relation between

and EW(NaID), such that EW(NaID) increases as

becomes redder. In the bin with the smallest Hβ width, objects with the bluest slopes, which are similar to AD predictions, are found to have

, supporting the line of sight dust hypothesis. This conclusion is also supported by the dependence of the Hα/Hβ line ratio on

. The implied relationship between continuum slope and dust reddening is given by

, and the implied reddening of a typical type-1 AGN with

is

. Photoionization calculations show that the line of sight dusty gas responsible for reddening is too ionized to produce the observed sodium features. Therefore, we argue that the sodium absorption arises in regions of the host ISM that are shielded from the AGN radiation along lines of sight to the stars, and the correlation with

arises since ISM columns along shielded and non-shielded sightlines are correlated. This scenario is supported by the similarity of the relation between

and the Na i column implied by our results with the relation in the Milky Way found by previous studies.
CLUSTERING OF LOCAL GROUP DISTANCES: PUBLICATION BIAS OR CORRELATED MEASUREMENTS? IV. THE GALACTIC CENTER
Authors: de Grijs Richard , Bono Giuseppe
Published: November 2016

Aiming at deriving a statistically well-justified Galactic Center distance, R
0, and reducing any occurrence of publication bias, we compiled the most comprehensive and most complete database of Galactic Center distances available to date, containing 273 new or revised R
0 estimates published since records began in 1918 October until 2016 June. We separate our R
0 compilation into direct and indirect distance measurements. The latter include a large body of estimates that rely on centroid determinations for a range of tracer populations, as well as measurements based on kinematic observations of objects at the solar circle, combined with a mass and/or rotational model of the Milky Way. Careful assessment of the Galactic Center distances resulting from orbital modeling and statistical parallax measurements in the Galactic nucleus yields our final Galactic Center distance recommendation of

. The centroid-based distances are in good agreement with this recommendation. Neither the direct measurements nor the post-1990 centroid-based distance determinations suggest that publication bias may be important. The kinematics-based distance estimates are affected by significantly larger uncertainties, but they can be used to constrain the Galaxy’s rotation velocity at the solar galactocentric distance,

. Our results imply that the International-Astronomical-Union-recommended Galactic Center distance (

) needs a downward adjustment, while its

recommendation (

km s−1) requires a substantial upward revision.
A COMPARATIVE STUDY OF LONG AND SHORT GRBS. I. OVERLAPPING PROPERTIES
Authors: Li Ye , Zhang Bing , Lü Hou-Jun
Published: November 2016

Gamma-ray bursts (GRBs) are classified into long and short categories based on their durations. Broadband studies suggest that these two categories of objects roughly correspond to two different classes of progenitor systems, i.e., compact star mergers (Type I) versus massive star core collapse (Type II). However, the duration criterion sometimes leads to mis-identification of the progenitor systems. We perform a comprehensive multi-wavelength comparative study between duration-defined long GRBs and short GRBs as well as the so-called “consensus” long GRBs and short GRBs (which are believed to be more closely related to the two types of progenitor systems). The parameters we study include two parts: the prompt emission properties including duration (T
90), spectral peak energy (

), low energy photon index (α), isotropic γ-ray energy (

), isotropic peak luminosity (

), and the amplitude parameters (f and

); and the host galaxy properties including stellar mass (

), star formation rate, metallicity ([X/H]), half light radius (R
50), angular and physical (

) offset of the afterglow from the center of the host galaxy, the normalized offset (

), and the brightness fraction

. For most parameters, we find interesting overlapping properties between the two populations in both one-dimensional (1D) and 2D distribution plots. The three best parameters for the purpose of classification are T
90,

, and

. However, no single parameter alone is good enough to place a particular burst into the right physical category, suggesting the need for multiple criteria for physical classification.
Building Information Model for Existing Buildings for Facilities Management
Authors: Carbonari Giulia , Stravoravdis Spyridon , Gausden Christine
Published: November 2016

The use of Building information modelling for the design and construction phase of a building has been thoroughly looked into by researchers and practitioners and there is evidence to support that it is beneficial for reducing cost, time and improving communication. Yet the potential use of BIM for the operational and management phase (Facilities management), besides maintenance schedules and equipment information and location, is still not clearly identified. The UK Government, institutional clients and major private owners are now demanding for BIM for new construction and major refurbishment but given that 70-75% of the current UK building stock will still be in use in 2050, a significant part of the existing facilities will not have an information model till the next major refurbishment, creating a major gap in the built environment. This paper presents a new framework aimed at creating information models for facilities management requiring minimal BIM skills and discusses the impact that models created for the operational stage would have on the whole life cycle of a building.
Impact of Fidelity in 3D Space Visualisation Across the Construction Asset Lifecycle
Authors: Saleeb Noha
Published: November 2016

3D virtual building models are used to help clients reach decisions during concept and detailed design phases. However, previously published research provides evidence for discrepancies between human perception of virtual and physical spaces; thus perceiving each virtual dimension (height, width, depth) differently from its physical counterpart, with varying percentages. This can affect clients' effective decision-making during coordination if 3D virtual representations are not perceived identical to their physical equivalent. This paper discusses the impact of these discrepancies beyond the design phases and into the whole lifecycle, construction and operations. Moreover, descriptive and inferential statistical analysis provides evidence of relationships between the physical and virtual perception differences in dimension, discussing possible factors contributing to perception discrepancies affecting the individual viewer, in 2 main areas 1) 3D authoring software 2) psychophysical factors. Possible solutions are also proposed to accommodate for the discrepancy between physical and virtual spaces.
Dental Diagnosis from X-Ray Images using Fuzzy Rule-Based Systems
Authors: Tuan Tran Manh , Duc Nguyen Thanh , Van Hai Pham , Son Le Hoang
Published: November 2016

In practical dentistry, dentists use their experience to examine dental X-ray images and to derive symptoms from patients for concluding possible diseases. This method is based solely on the own dentists' experience. Dental diagnosis from X-Ray images is proposed to support for dentists in their decision making. This paper presents an application of consultant system for dental diagnosis from X-Ray images based on fuzzy rule. Fuzzy rule was applied in many applications and has important role in computational intelligence, data mining, machine learning, etc. Based on a dental X-ray image dataset, we use Fuzzy C-Means to classify them into clusters and construct the rule set. Fuzzy Inference System is then used to evaluate the rules by three validity indices. These rules accompanied with symptoms from patients help dentists in diagnosing dental diseases. This method is implemented and experimentally validated on the real dataset of Hanoi Medical University Hospital, Vietnam against the related algorithms.
Generalized Intuitionistic Fuzzy Entropy Measure of Order α and Degree β and Its Applications to Multi-Criteria Decision Making Problem
Authors: Garg Harish , Agarwal Nikunj , Tripathi Alka
Published: November 2016

The objective of this manuscript is divided into two fold. Firstly, a more generalized intuitionistic fuzzy entropy measure of order and degree has been presented for measuring the degree of fuzziness of the set with a proof of its validity. A structured linguistic variable has been taken as an illustrative example to show its validity and superiority than the existing measures. Furthermore, based on this measure, an approach to deal with multi-criteria decision making (MCDM) problem is developed. Finally, a practical example is provided to illustrate the decision making process. A computed result is compared with the help of existing results. A sensitivity analysis on the different values of the parameters will make a decision maker more choice for accessing their results.
Social Media Communication in the Artisan Economy
Authors: Au Angela , Anthony Peter J.
Published: November 2016

Social media is a viable marketing and communication option for small businesses as it is cost-effective and easy to use. This study explores how small business owners in the artisan economy utilize social media to communicate with their customers. Artisan small businesses share similarities with small firms in other sectors, but they face unique challenges. Five artisan owners in the United States participated in semistructured interviews answering questions relating to marketing and communication. Artisan owners work in home-based businesses and rarely interact with customers in-person. Social media is a primary communication tool. Facebook, Twitter, and Instagram are sites artisan owners utilize to connect with existing and previous customers. Social media is helpful in maintaining customer relationships as well as reaching out to potential clients. When customers interact with artisan owners on social media such as liking and sharing posts, word-of-mouth marketing is created. Social media might help artisan owners increase customer loyalty and sales.
The Network Manager and the Governance of Business Networks
Authors: Tresca Roberta
Published: November 2016

Collaborating with other structures offers businesses – particularly smaller ones – excellent support to enable them to successfully face up to the challenges posed by globalised markets: by joining forces, creating systems and weaving networks of collaborative relationships with other businesses, SMEs can achieve the critical mass necessary to compete on global markets, because they can benefit from the “systemic” economies of scale that are typical of medium and large business, without losing any of the specificity that only a small manufacturing organisation can offer. However, the coordination and governance of a network is anything but simple, in view of the different types of distances (cognitive, psychological, cultural, geographical, etc.) that separate the businesses in the network. This explains the utility of a managerial figure outside the network (the Network Manager) with the ability to direct, coordinate and run the business network. This article focuses on the figure of the Network Manager, trying to define it by comparison with a few interesting managerial figures identified in the spectrum of management literature.
Moving from Theory to Practice
Authors: Bald Lisa-Marie , Orth Judith A. , Hargiss Kathleen M.
Published: November 2016

Technology integration continues to be a professional development concern, especially in elementary schools. It remains unclear why there is a difference between how teachers talk about using technology and how they apply it in teaching reading. The purpose of this investigation was to explore professional development options that would help teachers connect theory to practice by studying their decision-making process. In a case study design, 10 K-4 teachers participated in one 60-minute interview, one follow-up interview, and one 45-minute focus group. With the use of typological analysis, transcripts were coded for initial and emerging themes. Results indicated that integrating mobile devices was highly dependent upon teachers being self-directed learners. Teachers relied on informal collegial interactions when deciding to use mobile devices. Continuous professional development that addresses adult learning styles was recommended by the teachers to support technology adoption.
Organisations' Responsibilities towards Corporate Sustinability
Authors: Sambhanthan Arunasalam , Potdar Vidyasagar
Published: November 2016

This paper analyses published literature to determine the organizational responsibilities towards business sustainability. Over two hundred published research papers in this space have been subjected to content analysis using NVivo qualitative analysis tool. The results reveal that there are three major types of responsibilities namely social responsibilities, environmental responsibilities and the role based responsibilities which the organizations have in terms of ensuring corporate sustainability. These responsibilities have been found to be effectively achieved through effective corporate sustainability reporting practices, policy level concerns backed by values and principles, coordination of consumer inputs, ensuring stakeholder understanding about their roles and responsibilities and effective risk management backed by proper definition of roles and responsibilities. A number of conclusions along with implications for practice have been derived as the outcome of the documented research.
Predicting Student Satisfaction and Outcomes in Online Courses Using Learning Activity Indicators
Authors: Strang Kenneth David
Published: November 2016

The premise for this study was that learner interaction in an online web-based course could be assessed in relation to academic performance, or in other words, e-learning. Although some studies reveal that learner interaction with online content is related to student academic performance, it remains unproven whether this is casual, or even if there may be a significant correlation. Thus, this study seeks to measure if there is a directional and then a casual relationship between student online academic performance, engagement analytics and other online activity factors. A unique aspect of this study is that data is collected from Moodle engagement analytics as well as from the activity logs. Student academic performance is measured based on the grade achieved from an assessment designed to map to the course learning objectives.
Factors Affecting University Students' Intention to Use Cloud Computing in Jordan
Authors: Rababah Khalid Ali , Khasawneh Mohammad , Nassar Bilal
Published: November 2016

The aim of this study is to examine the factors affecting students' intention to use cloud computing in the Jordanian universities. To achieve this purpose, a quantitative research approach which is a survey-based was deployed. Around 400 questionnaires were distributed randomly to Information Technology (IT) students at four universities in Jordan and only 236 valid questionnaires were received. Using multiple regression technique, the results revealed that perceived usefulness, perceived ease of use, perceived security, perceived speed of access, and perceived cost of usage were significantly influencing the students' intention to accept and use cloud computing while the Affect was not. Furthermore, the results indicated that the developed model explains 50.4% of the variance in the students' intention to use cloud computing. Practically, the results of this study are considered fruitful for the universities and students to increase the usage of cloud computing in the educational settings.
Simulation Based Studies of Energy Saving Measures in the Aluminum Tool and Die Casting Industry
Authors: Henninger Matthias , Schlüter Wolfgang , Jeckle Dominik , Schmidt Jörg
Published: November 2016

This study, which focuses on analyzing aluminum melting and die casting procedures is part of the Smart Melting project in the research network Green Factory Bavaria (GFB). The aim of the present research project is to investigate these procedures and to suggest measures to increase the overall energy efficiency. The analysis starts with the capture of the operating structure, the relations between supply and consumption of liquid aluminum and an evaluation of aluminum furnaces themselves. The study concentrates on shaft furnaces whose specific energy consumption is 25 % higher than stated by the manufacturers. At the same time the melting capacity of the furnaces ranges at the lower end according to the manufacturer's data. The reason for this deviation is a discontinuous operation mode due to demand fluctuations. Consequently the flue gas has still a high temperature which means a high waste of energy. Based on these facts the furnace charge and operation mode have to be optimized and the high temperature flue gas can be used to preheat the pig aluminum.A numerical model of aluminum furnaces is applied to investigate this optimization potential. This model can simulate either a single aluminum furnace (case 1) or a furnace integrated in the entire manufacturing plant (case 2). The advantage of case 1 is the furnace's operation on its most efficient point because there is no influence of the die casting process. In case 1 an improvement of the furnace charge leads to a higher capacity utilization and therefore to a reduction of 30 % specific energy consumption and a 50 % increase of melting capacity. Whereas in case 2 the simulation of the entire manufacturing plant results in a rise of 25 % melting capacity and a 16 % decrease of specific energy consumption. The simulation proved increasing energy efficiency due to preheating the pig aluminum in both cases.
Assessment of Process Improvement Potential of Carbon Dioxide as a Cryogenic for Machining Operations
Authors: Gross Daniel , Heinz Andrea , Ebner Martin , Hanenkamp Nico
Published: November 2016

Cryogenic machining offers advantages compared to conventional cooling lubrication strategies particularly for difficult-to-cut and high-temperature-resistant materials such as titanium and nickel alloys. For implementation purposes environmental and cost factors are crucial for this new machining approach in series production. In order to facilitate investments it is mandatory to evaluate the technology’s potential prior to the final implementation decision. In the field of machining, in particular machining with cryogenic process cooling, there is no standardized and uniform procedure to assess this potential. In this paper a systematic approach and underlying analysis tool will be introduced to determine the potential of cryogenic processing in terms of resources and energy efficiency of the manufacturing operation. This approach satisfies the general conditions in a reasonable assessment effort as well as in the detail level. With this analysis tool, real production and process data are compared with results from scientific cryogenic tests and research and examined with regards to their applicability. Thus, it is possible in an early stage of the production to identify potentials in manufacturing and to take measures to realize these effects. In case cryogenic processing of a specific material has not been carried out so far, the similarity of this material to existing research results is determined. If positively assessed, the surrogates’ potential is transferred with a specific safety factor to the material. The analysis tool has been applied and refined in a real large-scale series production as well as in a complex component manufacturing and the holistic potential for e. g. durability, material removal rate (MRR) or savings regarding the use of metal working fluids (MWF) have been identified.
Developing a Composites Trailer for Multi-Purpose Sports Activities
Authors: Thorenz Benjamin , Klein Melanie , Mueller Thomas , Boehner Johannes , Steinhilper Rolf
Published: November 2016

This contribution firstly presents results gathered during the development of a lightweight multifunctional trailer made of composite material. Focusing on various cross country activities, such as mountain biking, hiking or trail running, significant technical improvements compared to existent products were obtained. This includes technical features like an integrated design to reduce accelerated mass, increase flexibility and provide shock suspension for the child carried during sports activities. As a key feature of the trailer, an agile steering system was engineered to both fit the specific requirements during the trailer’s use as a stroller and as a baby jogger. Due to the integrated design the weight of the single child prototype trailer was reduced by up to 50 % compared to conventional models and the driving comfort was considerably increased. To evaluate both the safety of the carried child during sports activities and the comfort for the adult as well as - last but not least - the resulting fun of those both users during sports activities a series of test rides was conducted. Selected results of the developed measuring setup and test track design are presented in this paper. Finally gathered measurement data are discussed and further design improvements are derived.
Efficient and Noise Reduced Design of Axial Fans Considering Psychoacoustic Evaluation Criteria
Authors: Zenger Florian , Münsterjohann Sven , Becker Stefan
Published: November 2016

Axial fans are the largest group of blowers and thus have a significant impact on their environment: Their demand for electrical power and the generation of a significant noise emission, have a negative impact on the environment.In this work the improvement of efficiency and reduction of noise emission are subject of the investigations. Several types of low-pressure axial fans are subject of this investigation. Measurements of pressure rise, efficiency and acoustic behavior will be presented for different blade geometries. The modifications of forward- and backward-skewed blades are compared to a unskewed blade geometry. The forward-skewed configurations show an improvement on the hydraulic properties, the efficiency and reduce the noise emission whilst the backward-skewed configurations improve the acoustic behavior at low flow rates with flow detachment occurring. Besides an acoustic quantification of the noise emission using the sound power level, psychoacoustic methods like loudness and sharpness were used.
Increasing the Format-Flexibility of Packaging Machines: Experimental Study on Laser Beam Sealing and Cutting
Authors: Götz Georg , Fink Johannes , Richter Christoph , Reinhart Gunther
Published: November 2016

The improvements of the format-flexibility as well as the resource and energy efficiency are important for the users and manufacturers of packaging machines. There is a positive interconnection of resource and energy efficiency with format-flexibility because e.g. the reduction of stand-by phases. To reach these goals, it is necessary to reduce the downtime and to increase the overall equipment effectiveness (OEE). The application of laser beam based processing technologies is very common in many different branches, e.g. automotive. One big advantage of the laser beam as a working tool is the high inherent flexibility. Different contours could be sealed and cut without any changeover by the use of flexible motion systems, e.g. deflection units or robots. However, there is a lack of use of laser based technologies in packaging machines. The focus of this paper is the experimental investigation of laser beam sealing and cutting with the same laser source. For this a 2 μm diode-pumped thulium fiber laser is used. Furthermore a flexible processing device will be shown and the practical use will be demonstrated.
Investigation of Different Sintering Methods on Ink-Jet-Printed Conductive Structures
Authors: Bahr Joachim , Kravchuk Oleksander , Reichenberger Marcus
Published: November 2016

Over the last decades ink-jet-printing has developed in many applications. The di-rect writing of materials such as silver (for conductive circuits) or polymers (for insulation or second layer) is an attractive method to reduce costs and save raw materials. For conductor paths silver inks with nanoparticles are used. To ensure a good dispersion the nanoparticles are mostly covered with organic compounds. To guarantee electrical conductivity the organic compounds have to be removed and the particles have to be sintered to minimize resistivity. This is done by heating up the silver structures. In this article we compare different meth-
ods of sintering conductive paths printed using a silver ink with a particle size of ≤ 50 nm.
The methods of sintering are the established thermal sintering in an oven, and alternatively laser sintering as well as electrical resistive sintering. Laser sintering is carried out with a semiconductor laser with a wavelength of 408 nm and different feeding speeds so the energy input in the structures can be varied. For electrical resistive sintering a DC-current is injected to the structures whereby they are heated up by the current. During electrical sintering the actual value of the resistance of the hot structures can be observed. Thereby the sintering can be stopped, when a certain value (of the hot structure) is reached.
The best parameters for both sintering alternatives are identified. The conductivity and the deviation of the conductivity of the sintered paths are determined and compared with the results achieved for thermal sintering. As a result, it can be stated, that both alternatives pro-vide specific advantages over thermal sintering such as lower deviations of the measured values or significantly lower process times. On the other hand, specific limitations might occur when using laser or electrical sintering.
Additionally, the individual amount of energy input for the three respective sintering pro-cesses is calculated and compared with each other to determine the most energy efficient sintering method. Also the process of direct contacting electrical devices with ink-jet-printing is compared with the standard process wire bonding related to the consumption of material and energy.
Feature Extraction and Classification of the Electric Current Signal of an Induction Motor for Condition Monitoring Purposes
Authors: Gebbe Christian , Tran Christin , Lingenfelser Florian , Glasschröder Johannes , Reinhart Gunther
Published: November 2016

A high availability of machines has always been important in production. One way to increase it is to avoid unscheduled production stops by detecting the onset of machine faults and to conduct preventative repairs. The detection part consists of the three steps signal acquisition, feature extraction and classification. This paper focuses on the last two steps through the example of an induction motor. Based on a publicly available motor current data set, features were extracted using the continuous wavelet transform. In the subsequent classification step eight different classification methods were compared with each other. It was found, that the accuracy of the classifiers varied significantly in a range from 20.6 % to 92.8 %. Moreover, the supportive vector machine, scoring an accuracy of 92.8 %, was the only classifier with an accuracy above 55.0 %.
Lean Data Services: Detection of Operating States in Energy Profiles of Intralogistics Systems by Using Big Data Analytics
Authors: Oette Cedric , Küfner Thomas , Reger Arnim , Boehner Johannes
Published: November 2016

Due to the rising energy costs and the increasing competition on the market the improvement of the energy efficiency in production systems can be a great chance for companies to gain an advantage compared to their competitors. Therefore, the transparency of the energy consumption of the several processes of such systems has to be known in detail. In this paper a method for the detection of operating states in production systems, based on big data analysis is introduced. The developed algorithm automatically detects different operating states in the current profile and improves his accuracy the longer it is used. To evaluate the developed data analysis algorithm, a defined process with a conveyor belt was considered and measured several times. The algorithm defines clusters from the measurements and identifies classes for the several operating states. With the naive Bayes classifier it is possible to categorize the clusters more fine-grained and faster than with a correlation function. An advantage of the method is that each new classified instance is taken into account for future unclassified instances. So it is possible to integrate a continuous learning process in production processes and to consider a slowly drift of states. Also, the subsequent addition of classes and attributes that are represented in this work by clusters, is possible at any time.
Efficient Method for Optimizing Calcium Silicate Masonry Unit Manufacturing Using Simulation-Based Optimization and Decomposition
Authors: Donhauser Toni , Lohse Joachim , Franke Jörg , Schuderer Peter
Published: November 2016

This paper describes an overall, simulation-based optimization approach to control plant operations for manufacturing calcium silicate masonry units (CS), which is directed towards and thus immediately applicable to practical processes. Starting from an investigation and classification of the CS production in order to differentiate the properties of each sub-process, specific target criteria are derived. To enable the influencing of these targets, relevant parameters including their mutual interdependencies are identified. On this basis, the criticality of each process step is assessed in order to determine improvement potentials and to investigate possible adjustments to the parameters.The elementary production types indicate a mix of the discontinuous and continuous processing in CS plants. Particularly, this work shows that through interrupting the continuous material flow, the hardening process is the main criteria for a plant’s success in meeting its targets, especially concerning energy efficiency. To achieve a feasible approach, the work develops a solving method geared to an optimized hardening process.Therefore, a formulation of a measureable target system is established, which is the prerequisite for modeling the whole optimization problem. An expedient decomposition of this optimization model to smaller sub-problems provides an efficient solving of these complex job-scheduling problems, in order to direct the method towards an operative use. The paper concludes with the determination of potential solving procedures for the overall problem and appropriate algorithms for solving the sub-problems.