Miracle-dz/UniFAR-FTUs huggingface dataset:
World Journal on Educational Technology: Current Issues

The study was carried out from 2018 to 2020 with the challenge how to assess the level of computational thinking. The research design is mixed since the disclosure of mutual influence of the components of the chain ‘learning programming – computational thinking – evaluating computational thinking’ requires the use of both qualitative and quantitative research methods. The conceptualisation of the ‘computational thinking’ idea is based on the premise of the impact of abstract thinking and computers on human thinking evolution. The structural interpretation of ‘computational thinking’, consisting of nine components, reflects the presence of a semantic link between teaching programming and the development of abstract computational thinking. Four levels (phenomenological, analytic–synthetic, set–prognostic and axiomatic) of computational thinking have been identified for each of these nine components. The study involved 102 elementary school students who are learning programming in Scratch. The guiding questions and problems we have developed for elementary school students are designed following the characteristics of the four levels of computational thinking. The results of the study showed that the ratio of ‘structural components’ to different levels of computational thinking, with the corresponding characteristics, allows one to determine the degree of its development or its individual components.
Adjustable Tensegrity Structures

A tensegrity is a lightweight space structure consisting of compression members surrounded by a network of tension members. They can be easily dismantled and therefore provide innovative possibilities for reusable and modular structures. Tensegrities can adapt their shape by changing their self stress, and when equipped with sensors and actuators, they can adapt to changing environments. A full-scale prototype of an adjustable tensegrity has been built and tested at Swiss Federal Institute of Technology (EPFL). This paper begins with a description of important aspects of the design, assembly, and static testing. Tests show that the structure behaves linearly when subjected to vertical loads applied to a single joint. Nonlinearities are detected for small displacements, for loads applied to several joints and for adjusting combinations of telescoping compression members. To predict behavior, dynamic relaxation - a nonlinear method - has been found to be reliable. Appropriate strut adjustments found by a stochastic search algorithm are identified for the control goal of constant roof slope and for the load conditions studied. When adjusting struts, an excessive number of adjustable members does not necessarily lead to improved performance.
Paper Deacidification in Large Workshops: Effectiveness and Practicability

For more than 20 years, methods of deacidifying and buffering papers have been the subject of numerous scientific studies all over the world. The most important recent works are reviewed by Lienardy & Van Damme. Paper conservators are confronted with a manifold supply of deacidification substances that are all praised as especially effective by the producers. The examination of the numerous procedures mostly takes place under nearly ideal laboratory conditions, which often cannot be maintained in the workshop. Therefore it could happen that, during practical application, a procedure shows less efficiency than predicted. The new central workshop of the state archives and scientific libraries of Baden-Württemberg always has great quantities of paper to be deacidified. It therefore seemed useful to verify the effectiveness of the applied substances parallel to the conservation treatment. The choice of an expensive but useless system should be avoided.
Control Strategies for Ambient Air Corn Drying

Alow temperature, low airflow corn drying model was used to examine different fan control strategies for finishing ambient air corn drying in the spring. The major objective was to obtain a more uniform final corn moisture content through the bin than is currently possible with continuous fan operation. Twenty three years of weather data for St. Paul, Minnesota were used. The effects of these different controls on maximum corn deterioration, time required to finish drying, and energy savings as compared to continuous fan operation were also examined. No supplemental heat was used. Intermittant fan operation can result in more optimum final moisture contents and slightly reduced energy requirements but at the expense of increased corn deterioration and an extended finishing date. Rewetting control strategies which sought to rewet the bottom layers of corn after safe moisture contents had been reached resulted in a more uniform moisture profile through the bin but at the expense of extra fan run time.
Municipal solid waste management in Dessie City, Ethiopia

Purpose – Purpose of this paper is to assess the municipal solid waste management (MSWM) system and resident practices towards municipal wastes in Dessie city of Ethiopia.Design/methodology/approach – A cross‐sectional study was conducted in 2008 and the data were generated by using self‐administered questionnaire and personnel observations using checklists. MSW generation and composition at household level was calculated by sorting and weighing the wastes from ten houses consecutively for seven days.Findings – The study revealed that Dessie municipality is mainly responsible for collection, transport and disposal of the wastes. Solid wastes generation rate at household level was found to be 0.45 kg/capita/day, having a high percentage of ash and food products. In total, 97 percent of respondents had knowledge about wastes and its management; however, the majority of them (73 per cent) believed that females are responsible for wastes management at household level. About half of the respondents (48 per cen.
Assessment of laser tracking and data transfer for underwater optical communications

We report on an investigation into optical alignment and tracking for high bandwidth, laser-based underwater optical communication links. Link acquisition approaches (including scanning of narrow laser beams versus a wide-angle ‘beacon’ approach) for different underwater laser-based communications scenarios are discussed. An underwater laserbased tracking system was tested in a large water flume facility using water whose scattering properties resembled that of a turbid coastal or harbour region. The lasers used were state-of-the-art, temperature-controlled, high modulation bandwidth gallium nitride (GaN) devices. These operate at blue wavelengths and can achieve powers up to ~100 mW. The tracking performance and characteristics of the system were studied as the light-scattering properties of the water were increased using commercial antacid (Maalox) solution, and the results are reported here. Optical tracking is expected to be possible even in high scattering water environments, assuming better components are developed commercially; in particular, more sensitive detector arrays. High speed data transmission using underwater optical links, based on blue light sources, is also reported.
Review of finite element methods for microwave and optical waveguides

The authors review the application of the finite element method to analysis of waveguide problems. They discuss the significance of different variational formulations, the modeling of the infinite domain of open-boundary waveguides, techniques to avoid spurious solutions, and matrix solution techniques. They briefly refer to the application of these techniques to waveguides containing nonlinear materials and to three-dimensional problems. >
Control-Type Selection at Isolated Intersections Based on Control Delay under Various Demand Levels

The Highway Capacity Manual (HCM 2000) displayed the figure Exhibit 10-15 for the purpose of forecasting the likely intersection control types for future facilities. Because this figure is from a source external to HCM, to verify it, this paper employs HCM methodologies for the estimation and comparison of control delay, the choice measure of effectiveness at intersections controlled by signal, all-way stop signs, and two-way stop signs. After detailed analyses of more than 5,000 cases using Highway Capacity Software, results of control delay with various control types under a wide range of demand conditions were charted for comparison with Exhibit 10-15. It is found that Exhibit 10-15 is inconsistent with the results from HCM methodologies and, perhaps, should be replaced with the figures developed in this paper. On the basis of the criterion of minimizing delay alone, it is found that if demand is unbalanced between major and minor streets and if the traffic is low on minor streets, two-way-stop control should be used; if demand is somewhat balanced and minor streets see low to medium traffic, all-way-stop control is preferred; otherwise, signal control should be favored. The paper also demonstrates that the percentage of left-turning traffic has a significant effect on decisions involving intersection control types.
Topographie Presentation of the Dipolar Content of Cardiac Electric Field

The electrocardiographic signal provides the unique Information about the Status and activity of the heart, äs a generator of cardio-electric field. In current clinical practice, it is mostly registered by the means of a Standard I2-lead system and presented äs scalar electrocardiograms. However, the Information obtained in this way is characterized by a considerable redundancy, and the conceptual model used for the Interpretation is complicated.
Analysis of Day-to-Day Variability in an Individual's Action Space: Exploration of 6-Week Mobidrive Travel Diary Data

Using 6-week travel diary data from Karlsruhe and Halle, Germany, this study examines the characteristics of individuals' action space. The extension of action space is represented by the second moment of the activity locations that it contains. Day-to-day variation in the second moment is examined. The results show that out-of-home activity orientation and commitment (e.g., obligatory activities on weekdays and discretionary activities on weekend days) influence the extension of action space. For workers and students on weekdays, the spread of activity locations and the distance from home to the centroid of activity locations are relatively stable from day to day. A substantial portion of the variations in their action spaces is due to unexplained differences across individuals that remain stable over time for each individual (unobserved heterogeneity). In contrast, random factors have dominant influences on nonworkers' weekday action spaces and on all individuals' weekend action spaces.
Aging of nonceramic insulators due to corona from water drops

The fundamental principles of water drop corona as an aging mechanism for nonceramic insulators are presented. It is demonstrated that water drops in the sheath regions enhance the electric field and may cause corona which can play an important role in long-term performance. Electric field enhancement caused by water drops in different locations on the shed and sheath are demonstrated by means of electric field calculations and small scale experiments. The threshold magnitude of the surface electric field for corona from water drops is presented for two silicone rubber surfaces having different hydrophobic properties. The effect of water drop corona activity on the properties of the surface material is shown using small scale aging experiments.
Research and Development in Methods of Soakaway Design

Soakaways have been a traditional method of disposal of stormwater for decades, and their usage has mainly been determined by the absence of a convenient watercourse, drain, or sewer into which to discharge runoff arising from roofs and paved surfaces. Today, soakaways are still being installed at a rate of tens of thousands per annum, despite the extensive storm-sewer systems in the UK. It is therefore surprising that little systematic research and development has been undertaken into their design and performance, or into the appropriate forms of maintenance to be conducted to extend operational life. The paper briefly describes the recent research into, and design approaches for, the sizing of soakaways. An example is given of the use of Building Research Establishment Digest 365 to review alternative soakaway designs and to assess the cost implications. Some field data are reported which (a) illustrate the seasonal variability and difficulties of determination of the soil infiltration rate, and (b) provide some insight into the pollution issues from the use of soakaways.
11W broad area 976 nm DFB lasers with 58% power conversion efficiency

A report is presented on how distributed feedback (DFB) lasers can achieve high optical power and power conversion efficiency together with a narrow vertical emission angle. Recently developed 976 nm DFB lasers emit 11 W, have a maximum power conversion efficiency of 58%, a spectral linewidth of ∼0.4 nm FWHM and a narrow vertical far field of 28° FWHM. This considerable enhancement was obtained with an improved epitaxy design and optimised grating fabrication process. These are DFB lasers that achieve power, efficiency and emission angle values comparable to conventional Fabry-Perot lasers, but with spectral stabilisation. Accordingly, these lasers are particularly well suited for pumping fibre and solid-state lasers.
Numerical Study of the Internal Flow Field Characteristics in Mixed Flow Turbines

Presented is a numerical investigation of the characteristics of the internal flow field of a high-speed low-pressure ratio mixed flow turbine of 95.14 mm tip diameter. A commercial computational fluid dynamics (CFD) code has been successfully employed. This has been carefully validated to experimental data taken from a turbine test facility at this institution. A comparison to gated (in phase with the turbine rotation) Laser Doppler Velocimetry measurements at the turbine trailing edge and total to static efficiencies at various operating conditions, was made showing good agreement. Details of the internal flow field from a numerical study using a 393,872 cell density model are presented. These details have been compared to a radial turbine of similar geometry and performance characteristics, also analyzed using the same cell density and analysis and boundary conditions. The flow field was found to be highly three-dimensional with the tip leakage vortex as the dominant secondary flow feature. The tip clearance flow was found to be significantly influenced by the relative motion of the shroud wall, which suppressed the development of a vortex within the mainstream passage particularly in the inducer region. Comparison to the radial turbine has shown noticeable differences concentrated in the inducer region where the greater Coriolis acceleration in the radial turbine is more influential in the development of secondary flows. Considerable loss is observed localized at the blade leading edge tip region along the full length of the blade pitch; this is associated with the increased streamline curvature in the meridional plane.Copyright © 2002 by ASME
Sensitivity of water management models to approaches for determining soil hydraulic properties

Data that define the relationships between the soil-water content (q), hydraulic conductivity (K), and tension (h) are important inputs to hydrologic models, however, they are difficult to measure and are often estimated from more easily determined soil physical properties. This article presents comparisons of using measured versus estimated q(h) and K(h) data to simulate evapotranspiration, infiltration, runoff, and drainage with the PREFLO and DRAINMOD water management models. Both models reacted similarly to the estimated data by altering the simulated volumes of ET and drainage. The models were most sensitive to differences in the K(h) data at tensions between 0 and 1.5 m. PREFLO was more sensitive than DRAINMOD to the saturated water content estimated from soil texture. The ability to simulate soil-water storage and movement with PREFLO or DRAINMOD was more a function of input data accuracy than the model.
Drag Reduction Study about Bird Feather Herringbone Riblets

Flying bird has gradually formed airworthy structures e.g. streamlined shape and hollow shaft of feather to improve flying performance by millions of years natural selection. As typical property of flight feather, herringbone-type riblets can be observed along the shaft of each feather, which caused by perfect alignment of barbs. Why bird feather have such herringbone-type riblets has not been extensively discussed until now. In this paper, microstructures of secondary feathers are investigated through SEM photo of various birds involving adult pigeons, wild goose and magpie. Their structural parameters of herringbone riblets of secondary flight feather are statistically obtained. Based on quantitative analysis of feathers structure, one novel biomimetic herringbone riblets with narrow smooth edge are proposed to reduce surface drag. In comparison with traditional microgroove riblets and other drag reduction structures, the drag reduction rate of the proposed biomimetic herringbone riblets is experimentally clarified up to 15%, much higher than others. Moreover, the drag reduction mechanism of herringbone riblets are also confirmed and exploited by CFD.
Scattering of vertically polarized electromagnetic waves from infinite dielectric cylinders embedded in a lossy medium

The problem of scattering of vertically polarized electromagnetic waves from underground cylindrical objects is investigated in this paper. The analysis used here can be considered to be an extension of previous integral-equation techniques dealing with the horizontal-polarization scattering problem from underground tunnels or conducting wires. Numerical data for the far-field region of buried cylindrical objects are plotted and some interesting conclusions based on these results are discussed and compared with those of the horizontal scattering problem.
Modeling of electronic transport in metallic carbon nanotube interconnects in the presence of electron‐phonon interactions

Metallic carbon nanotubes are being considered as a candidate to potentially replace copper as an interconnect material in next generation nanotechnology integrated circuits.In this article, we have examined the electronic transport behavior in metallic carbon nanotubes using a self consistent nonequilibrium Green's function method. We have included the effects of electron‐phonon interactions in our model. Results show that conductivity decreases in the ballistic limit due to localized disorder effects even with a weak disorder potential. We are also able to show that optical phonons (both LO and TO modes) are the dominant mechanisms that govern the mean free path of conduction in the nanotube. Our calculations show an excellent agreement with experimental results available in the literature. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2477–2483, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27145
Navigating a Sea of Change

Using the profound movements of ocean waters as an analogy, Lauralee Alben has devised a comprehensive analysis that helps organizations navigate major transformations—sometimes through uncharted territory. The many elements of her methodology probe the context, as well as the nature and breadth, of change and exploit design as an essential vehicle for conveying new ideas and perceptions.
Cross-training workers in Dual Resource Constrained systems with heterogeneous processing times

In this paper, we explore the effect of cross-training workers in Dual Resource Constrained (DRC) systems with machines having different mean processing times. By means of queuing and simulation analysis, we show that the detrimental effects of pooling (cross-training) previously found in single resource constrained (SRC) heterogeneous systems are also apparent in DRC heterogeneous systems. Fully cross-training workers in DRC heterogeneous systems is only beneficial if the differences between mean processing times are not too large, otherwise cross-training should be pursued within homogeneous subgroups of machines. Due to the limited machine availability, DRC systems are unable to use some of the potential assignment flexibility from cross-trained workers (pooled queues) that can be used in SRC systems. However, it appears that this restriction in the DRC system may even improve the system mean flow (waiting) time performance compared to the SRC system for relatively large differences in processing time. Finally, in fully flexible multiple server queuing systems, restricting the assignment flexibility by applying a decentral when-rule (i.e. a commonly used labour assignment rule in practice and research) instead of a central when-rule also seems to improve the mean flow time performance under processing time differences.
Formal tests for LLM approaches using refined cockpit display technology

Results are presented from formal flight and simulation experiments to test a new primary flight display (PFD)/refined multifunction display (MFD) system, with a computer generated dynamic pathway, as a viable means for a pilot to accurately and efficiently control and navigate an aircraft. For flight control, the PFD uses a computer generated highway-in-the-sky (HITS) pathway and a synthetic vision terrain image of the view outside the aircraft, with an overlay of all the essential flight technical data. For navigation, the MFD provides a moving map with a dynamic pathway to aid the pilot. The total PFD/MFD system provides a predictive method for flying an aircraft, as opposed to the reactive method associated with conventional needle and dial instruments. Fifteen low-to-average-experience subject pilots were selected to compare the PFD instrumentation system to a conventional instrumentation system. A non-precision global positioning system (GPS) area navigation (RNAV) approach to runway 20 at Wakefield Municipal Airport, VA, (AKQ) was used. The hypothesis was that the intuitive nature of the PFD instrumentation system will provide greater situational awareness, improved accuracy, and less pilot workload during flight in instrument meteorological conditions (IMC) compared to using conventional round dial instrumentation.
A single-sided micromachined piezoresistive SiO2 cantilever sensor for ultra-sensitive detection of gaseous chemicals

This paper presents a novel SiO2 microcantilever sensor for high-sensitive gaseous chemical detection. A thin single-crystalline silicon piezoresistor is integrated in the SiO2 cantilever for low-noise and high-resoluble signal readout. The paper relates the MEMS formation, modeling and detecting experiments of the sensor. The micro-fabrication of the cantilever sensor is processed at a single side (front side) of the silicon wafer, combined with functionalization of a self-assembled monolayer (SAM) on the sensing cantilever for specific molecular capturing. The model of the piezoresistive SiO2 cantilever sensor is given by using both analysis and simulation, resulting in good agreement with the measuremental data. With the cantilever modified by the specific SAM, the detecting performance of the sensor is experimentally obtained. Attributed to the high sensitivity and the low electric noise of the piezoresistive SiO2 cantilever, ammonia gas of 0.1 ppm level concentration and dimethyl methylphosphonate vapor of 10 ppb concentration have been well detected. The integrated cantilevers are promising for inexpensive, highly resoluble and portable chemical/biological detection.