Taiwan Association of Engineering and Technology Innovation: E-Journals
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Evaluation of Infill Effect on Mechanical Properties of Consumer 3D Printing Materials
Get PDFDuring the additive manufacturing “boom” of the last decade, consumer level 3D printers have kept pace with commercial/industrial printers, both in numbers and features. However, in material characterization data, the access to date for the consumer has significantly lagged behind. Consumer level 3D printers provide a significant asset to entrepreneurs, small businesses, universities, college students, and hobbyists due to the low initial capital cost and relatively low operational costs. Commercial grade 3D printers and the associated filaments sold for their use typically have well documented material properties and print parameters. Consumer 3D printers, however, typically have limited or no access to mechanical test data for their materials. This paper describes the work of the authors to fill the existing knowledge gap in the mechanical properties of consumer level 3D printer filament. ASTM Tensile (D638) tests were performed on samples produced by two commercially available 3D printers. The materials tested include PLA, ABS, PETG, various nylons, Polycarbonate/ABS, and ASA filaments. Samples were printed with infill percentages ranging from 15% to 100% to test for tensile properties
A Novel Stretch Sensor to Measure Venous Hemodynamics
Get PDFChronic venous insufficiency is a debilitating condition causing varicose veins and venous ulcers. The pathophysiology includes reflux and venous obstruction. The diagnosis is often made by clinical examination and confirmed by Venous Doppler studies. Plethysmography helps to quantitatively examine the reflux and diagnose the burden of deep venous pathology to better understand venous hemodynamics, which is not elicited by venous duplex examination alone. However, most of these tests are qualitative, expensive, and not easily available. In this paper, we demonstrate the potential use of a novel stretch sensor in the assessment of venous hemodynamics during different maneuvers by measuring the change in calf circumference. We designed the stretch sensor by using semiconductor strain gauges pasted onto a small metal bar to form a load cell. The elastic and Velcro material attached to the load cell form a belt. It converts the change in limb circumference to a proportional tension (force of distension) when placed around the calf muscle. We recorded the change in limb circumference from arrays of stretch sensors by using an in-house data acquisition system. We calculated the venous volume (VV), venous filling index (VFI), ejection fraction (EF) and residual venous volume (RVV) on two normal subjects and on two patients to assess venous hemodynamics. The values (VV > 60 ml, VFI < 2ml/s, EF > 60%, RVV < 35%) in normal subjects and (VV < 60 ml, VFI > 2ml/s, EF < 60%, RVV > 35%) in patients were comparable to those reported in the literature
Dynamic Biometric Signature - an Effective Alternative for Electronic Authentication
Get PDFThe use of dynamic biometric methods for the authentication of people provides significantly greater security than the use of the static ones. The variance of individual dynamic properties of a person, which protects biometric methods against attacks, can be the weak point of these methods at the same time.This paper summarizes the results of a long-term research, which shows that a DBS demonstrates practically absolute resistance to forging and that the stability of signatures provided by test subjects in various situations is high. Factors such as alcohol and stress have no influence on signature stability, either. The results of the experiments showed that the handwritten signature obtained through long practice and the consolidation of the dynamic stereotype, is so automated and stored so deep in the human brain, that its involuntary performance also allows other processes to take place in the cerebral cortex. The dynamic stereotype is composed of psychological, anatomical and motor characteristics of each person. It was also proven to be true that the use of different devices did not have a major impact on the stability of signatures, which is of importance in the case of a blanket deployment.The carried out experiments conclusively showed that the aspects that could have an impact on the stability of a signature did not manifest themselves in such a way that we could not trust these methods even used on commercially available devices. In the conclusion of the paper, the possible directions of research are suggested
An Intelligent System to Predict Risk and Costs of Cargo Thefts in Road Transport
Get PDFThe article looks at the simulations of the possibility of theft risk occurrences with taking into account different types of cargo, its price and a carriage phase. The risk analysis was conducted by using original algorithms developed on the basis of artificial neural networks that take into account, among others, the probability of the cargo theft risk in a particular stage of the order for different types of cargo. The authors specify the forecasted loss values that refer to the type of stolen cargo, including penalties depending on the stage of the carriage. The research and the method described in this article enable the engineers to create a tool/program that facilitates the process of making decisions about additional cargo insurance or the use of monitoring systems for the location and parameters of the cargo. The method can also be used by the insurance companies to determine rates for cargo insurance
Applying Project Management Perspective for ERP Implementation: A Case Study
Get PDFThe case-study company is a well-known enterprise whose primary product is precision locknuts in Taiwan. With the rise of sales performance, the legacy enterprise resource planning (ERP) system does not provide the degree of reliability and maintainability the case company needed. In order to meet the growing needs of enterprise, the case company faces to the challenge of application integration within the enterprise. The ERP implementation success depends on the rigor of the project management processes. In this research, firstly, case study approach is adopted to investigate how poor project management imperil the implementation of an ERP system. Having learned the lessons from the failure of its first ERP implementation, the case company applies the theory of business process reengineering (BPR) to explore and rationalize the business processes, and design its project management practices to successfully carry out its second ERP implementation. And the goal directed project management (GDPM) principles are applied to develop a proper ERP implementation plan. The summary descriptions of the important aspects of ERP implementation are stated that the sponsor or the client of the project, the goals, and limitations on the project, and time are included. This study explores and identifies the critical elements of project management to provide an effective guidance for the first implementation stage
A Direct Lyapunov-Backstepping Approach for Stabilizing Gantry Systems with Flexible Cable
Get PDFTrolley positioning and payload swinging control problem of a flexible cable gantry crane system are addressed in this paper. The system’s equations of motion that couple the crane’s cable and actuators dynamics are derived via extended Hamilton’s principle. The control signal is designed based on the Lyapunov direct method to derive control force and backstepping technique is employed to determine input signal for the actuator. The stability of the closed loop system is proven analytically. Numerical simulations are included to demonstrate the effectiveness and robustness of the closed-loop system
A Study on Unmanned Surface Vehicle Combined with Remotely Operated Vehicle System
Get PDFIn this paper, we proposed a new hybrid system that combines an USV and the ROV. It is designed to overcome the cumulative navigation error and the battery problem for long time operation. The USV is connected to the underwater robot with a tether cable that enables GPS data transmission and stable power supply. In addition, by installing a winch system on the USV, it is possible to move and to retrieve the ROV for long distance travel and for depth control. The ROV equipped with underwater sensors which can acquire underwater image capture and undersea topography information and can transmit it to the land through the USV in real time was designed. Line-of-sight navigation and dynamic positioning algorithm were studied for the USV to perform autonomous navigation and keeping-position while ROV is doing underwater operations. Good performance of the USV was verified by simulation and real sea experiment using the developed hybrid USV and ROV
Battery Management System for 24-V Battery-Powered Electric Wheelchair
Get PDFThis paper describes a simplified battery-management system using a digital signal processor for a 24-V battery-powered electric wheelchair to modulate and protect the battery from operating outside its safe operating area, such as over-temperature, under-temperature, over-voltage, under-voltage, over-current discharge, or over-current charging. Using the buck-boost circuit topology, we achieved and demonstrated both battery balance and protection in a prototype 12-V/40-Ah series-connected two-battery module. Simulation results show that the proposed battery management system is feasible for a 24-V battery-powered electric wheelchair application
Open Innovation in Small and Medium Size Enterprises-Perspective from Virtual Collaboration
Get PDFAbstractOpen innovation is a growing concern in today’s manufacturing industries, especially within small and medium size enterprises (SMEs). Due to the resource scarcity, SMEs need to be collaborated with the objective to share knowledge and expertise to develop innovative product, which lead them to become more competitive in market segment. In this research study, generic concept and a novel framework on open innovation are elaborated. In addition, a methodological guideline to form and execute a collaborative business network is proposed. The framework and the methodological guidelines are presented to facilitate an open innovation management within the collaborative partner industries. Moreover, associated factors to manage a successful business network with open innovation are also identified along with possible challenges. Finally, within the scope of this research study, a case business network is presented, where the concept of open innovation is orchestrated within the partner organizations via web-enabled communication portal
A New Partitioning Scheme for PTS Technique to Improve the PAPR Performance in OFDM Systems
Get PDFA high peak-to-average-power ratio (PAPR) is the primary drawback faced by the orthogonal frequency division multiplexing (OFDM) systems in the practical applications. Meanwhile, Partial Transmit Sequence (PTS) is regarded as one of the efficient PAPR reduction techniques in OFDM systems. PTS technique depends on partitioning the input data into the several subblocks in the frequency-domain and weighting these subblocks by a set of phase factors in the time-domain. As the result, there are three common types of subblocks partitioning schemes have been adopted in the PTS technique, interleaving scheme, adjacent scheme, and pseudo-random scheme. Each one of the conventional partitioning schemes has PAPR reduction performance and a computational complexity level different from others. In this paper, a new subblock partitioning scheme named terminals exchanging segmentation (TE-PTS) scheme has been proposed to improve the PAPR performance in PTS technique better than that of the interleaving scheme. The simulation results and the numerical calculations indicate that the PAPR reduction capacity of the proposed scheme is superior to that of interleaving scheme without increasing the computational complexity