Taiwan Association of Engineering and Technology Innovation: E-Journals
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Elementary School Teachers’ Conceptions of Teaching Mathematics with Digital Game-based Teaching
Get PDFThis study aimed to investigate the factors accounting for mathematics teaching self-efficacy and to examine the relationships among Taiwanese teachers’ mathematics teaching self-efficacy, teaching and learning conceptions, technological–pedagogical content knowledge for the digital learning, and attitudes toward game based learning. A total of 195 math teachers from 23 elementary schools in Taiwan were invited to take part in the study. After ensuring the validity and reliability of each questionnaire, the results indicated that each measure had satisfactory validity and reliability. Furthermore, the results revealed that teaching and learning conceptions, technological pedagogical content knowledge for the digital learning, and attitudes toward game-based learning mediated the relationship between teaching and learning conceptions and mathematics teaching self-efficacy, suggesting that knowledge of and attitudes toward digital game-based learning mediated the positive relationship between constructivist conceptions of teaching and learning and outcome expectancy; however, it mediated the negative correlations between traditional conceptions of teaching and learning and teaching efficacy
Advanced Manufacture of Spiral Bevel and Hypoid Gears
Get PDFIn this study, an advanced method for the manufacture of spiral bevel and hypoid gears on CNC hypoid generators is proposed. The optmal head-cutter geometry and machine tool settings are determined to introduce the optimal tooth surface modifications into the teeth of spiral bevel and hypoid gears. The aim of these tooth surface modifications is to simultaneously reduce the tooth contact pressure and the transmission errors, to maximize the EHD load carrying capacity of the oil film, and to minimize power losses in the oil film. The proposed advanced method for the manufacture of spiral bevel and hypoid gears is based on machine tool setting variation on the cradle-type generator conducted by optimal polynomial functions and on the use of a CNC hypoid generator. An algorithm is developed for the execution of motions on the CNC hypoid generator using the optimal relations on the cradle-type machine. Effectiveness of the method was demonstrated by using spiral bevel and hypoid gear examples. Significant improvements in the operating characteristics of the gear pairs are achieved
Pollution Monitoring System Using Gas Sensor Based On Wireless Sensor Network
Get PDFCarbon monoxide (CO) and carbon dioxide (CO2) gases are classified as colorless and odorless gas so we need special tools to monitor their concentration in the air. Concentration of air pollution of CO and CO2 that are high in the air will give serious effects for health status. CO is a poisonous gas that damages the circulation of oxygen in the blood when inhaled, while CO2 is one of the gases that causes global warming. In this paper, we developed an integrated pollution monitoring (IPOM) system to monitor the concentration of air pollution. This research implemented three sensor nodes (end-device) which each node contains CO and CO2 sensors on the gas sensors board to perform sensing from the environment. Furthermore, the data taken from the environment by the sensor will be sent to the meshlium gateway using IEEE 802.15.4 Zigbee communications and processed by the gateway in order to be sent to the computer server. The data is stored in meshlium gateway using MySQL database as a backup, and it will be synchronized to the MySQL database in the computer server. We provide services for public to access the information in database server through a desktop and website application
Influences of Dynamic Moving Forces on the Functionally Graded Porous-Nonuniform Beams
Get PDFThe dynamic response of functionally graded (FG) porous-nonuniform beams subjected to moving forces is investigated. The beam cross-section is assumed to vary longitudinally in the width direction by a linear or quadratic function. A modified rule of mixture, taking the effect of porosities into account, is adopted in evaluating the effective material properties. Based on Timoshenko beam theory, governing equations of motion are derived from Hamilton's principle, and they are solved by a finite element model. The dynamic response of a simply supported FG porous beam is computed with the aid of the Newmark method. The validation of the derived formulation is confirmed by comparing the obtained numerical results with the data available in the literature. A parametric study is conducted to highlight the effect of the material inhomogeneity, porosity volume fraction, section profile and loading parameters on the dynamic behavior of the beams
Preprocessing Algorithm for Deciphering Historical Inscriptions Using String Metric
Get PDFThe article presents the improvements in the preprocessing part of the deciphering method (shortly preprocessing algorithm) for historical inscriptions of unknown origin. Glyphs used in historical inscriptions changed through time; therefore, various versions of the same script may contain different glyphs for each grapheme. The purpose of the preprocessing algorithm is reducing the running time of the deciphering process by filtering out the less probable interpretations of the examined inscription. However, the first version of the preprocessing algorithm leads incorrect outcome or no result in the output in certain cases. Therefore, its improved version was developed to find the most similar words in the dictionary by relaying the search conditions more accurately, but still computationally effectively. Moreover, a sophisticated similarity metric used to determine the possible meaning of the unknown inscription is introduced. The results of the evaluations are also detailed
Behavioural Assessment of Blood-Brain Barrier Opening Induced by Various Ultrasound Parameters
Get PDFFocused ultrasound (FUS)-induced opening of the blood-brain barrier (BBB) in the presence of microbubbles is prospective for a targeted drug delivery to the brain lesion. However, the safety of this technology has been addressed recently. The purpose of this study was to assess the behavioural changes following the FUS induced-BBB disruption (BBBD). The behavioural assessment of rats were tested using the open field and hole-board from day 1 through day 32 after undergoing BBBD induced by FUS with either a mild or heavy parameter. We found that heavy BBBD induced behavioral changes, including significantly increased locomotor activity and a longer latency to nose poke for baits. Additionally, mild BBBD resulted in significant decrease of central activity. Therefore, the behavioural changes after FUS induced BBBD should be considered before clinical application
Bending Resistance Capacity of Steel Pile Caps Strengthened with Perfobond Shear Connectors
Get PDFThis study proposes a new perfobond shear connector, which can be used to strengthen the steel pile cap embedded into the structural foundation. The bending resistance capacity of the steel pile cap strengthened with the proposed perfobond connectors is evaluated by performing a test on seven specimens. Test parameters include the type of perfobond shear connectors, infilled concrete depths and number of L-shaped steel plates. The lateral load versus displacement curve is plotted for all specimens, and their failure modes are identified. The effects of the test parameters on the bending resistance capacity of the specimen are examined in this work
Photoluminescence Study of Hydrothermally Grown ZnO Nanostructures
Get PDFIn this work, the hydrothermally grown ZnO nanostructures were successfully prepared using the aqueous solution of zinc nitride dehydrate (Zn(NO3)2). The effect of solution molarity on the optical and structural properties of ZnO nanostructures were studied by temperature dependent photoluminescence (PL) measurements. The intensity ratio of the ultraviolet emission to the visible emission is calculated. It is found that the calculated results are also dependent on the solution molarity and consistent with the crystal quality of ZnO nanostructures
Proactive Management of Water Quality in Aquifer Storage Transfer and Recovery
Get PDFThis paper reports the status of an ongoing effort to ensure the quality of water produced at an Aquifer Storage Transfer and Recovery (ASTR) site in South Korea. ASTR is one of the managed aquifer recharge techniques in which water is intentionally recharged to suitable aquifers for subsequent recovery. Surface water injected to an aquifer is converted into water of drinkable quality by natural process. In an ASTR project being developed in the densely populated delta area of the Nakdong River basin, a new framework is being implemented in which water safety is addressed through the analysis and control of biological, chemical, and physical hazards from intake, pretreatment, injection and recovery, to distribution and consumption of water. The task is done by the incorporation of Hazard Analysis and Critical Control Point (HACCP) to the ASTR process. Originated from the food industry, HACCP identifies, evaluates, and controls hazards to ensure the safety of the product. Principles of HACCP were applied to the ASTR water production system. Hazard analysis revealed that most hazardous events were due to the chemicals transported in the basin. Risk assessment was conducted to identify the sources of chemicals which pose a potential threat to the water quality of the ASTR site. Such information will be valuable for the proactive management of chemicals at the basin scale. Critical control points (CCP) were determined by the decision tree method, and critical limits for water quality parameters at CCPs were established subsequently
Buckling Experiment on Anisotropic Long and Short Cylinders
Get PDFA buckling experiment was performed on anisotropic, long and short cylinders with various radius-to-thickness ratios. The 13 cylinders had symmetric and anti-symmetric layups, were between 2 and 6 in terms of the length-to-radius ratio, between 154 and 647 in radius-to-thickness ratio, and made of two kinds of carbon fiber reinforced plastic (CFRP) prepreg with high or low fiber modulus. The theoretical buckling loads for the cylinders were calculated from the previously published solution by using linear bifurcation theory considering layup anisotropy and transverse shear deformation and by using deep shell theory to account for the effect of length and compared with the test results. The theoretical buckling loads for the cylinders were calculated from the previously published solution by using linear bifurcation theory considering layup anisotropy and transverse shear deformation and by using deep shell theory to account for the effect of length. The knockdown factor, defined as the ratio of the experimental value to the theoretical value, was found to be between 0.451 and 0.877. The test results indicated that a large length-to-radius ratio reduces the knockdown factor, but the radius-to-thickness ratio and other factors do not affect it