Taiwan Association of Engineering and Technology Innovation: E-Journals

    Performance Evaluations for IEEE 802.15.4-based IoT Smart Home Solution

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    The Internet of Things (IoT) is going to be a market-changing force for a variety of real-time applications such as e-healthcare, home automation, environmental monitoring, and industrial automation. Low power wireless communication protocols offering long lifetime and high reliability such as the IEEE 802.15.4 standard have been a key enabling technology for IoT deployments and are deployed for home automation recently. The issues of the IEEE 802.15.4 networks have moved from theory to real world deployments. The work presented herein intends to demonstrate the use of the IEEE 802.15.4 standard in recent IoT commercial products for smart home applications: the Smart Home Starter Kit. The contributions of the paper are twofold. First, the paper presents how the IEEE 802.15.4 standard is employed in Smart Home Starter Kit. In particular, network topology, network operations, and data transfer mode are investigated. Second, network performance metrics such as end-to-end (E2E) delay and frame reception ratio (FRR) are evaluated by experiments. In addition, the paper discusses several directions for future improvements of home automation commercial products

    Experimental Investigation into Mechanical Properties of Nanomaterial-reinforced Table Tennis Rubber

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    A new table tennis rubber is prepared consisting of carbon nanotubes, zinc oxide and titanium oxide added to a mixture of natural and synthesized rubber. The Nano-reinforced rubber is attached to wooden table tennis blades and patterned with four different surface structures, namely flat, long pimples, short pimples and medium pimples. The results show that of the five rubbers, the Nano-reinforced rubber with a flat surface offers a significantly improved elastic and mechanical performanc

    A Simplified Approach to Multivariable Model Predictive Control

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    The benefits of applying the range of technologies generally known as Model Predictive Control (MPC) to the control of industrial processes have been well documented in recent years. One of the principal drawbacks to MPC schemes are the relatively high on-line computational burdens when used with adaptive, constrained and/or multivariable processes, which has warranted some researchers and practitioners to seek simplified approaches for its implementation. To date, several schemes have been proposed based around a simplified 1-norm formulation of multivariable MPC, which is solved online using the simplex algorithm in both the unconstrained and constrained cases. In this paper a 2-norm approach to simplified multivariable MPC is formulated, which is solved online using a vector-matrix product or a simple iterative coordinate descent algorithm for the unconstrained and constrained cases respectively. A CARIMA model is employed to ensure offset-free control, and a simple scheme to produce the optimal predictions is described. A small simulation study and further discussions help to illustrate that this quadratic formulation performs well and can be considered a useful adjunct to its linear counterpart, and still retains the beneficial features such as ease of computer-based implementation

    Optical Design of Full View Lens based on Energy Luminance Analysis Chart of Stray Light

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    This paper presented optical design software (CODE V) in combination with stray light simulation software (Light Tools) to develop and analyze the influence of 360 degree lens stray light on MTF. We study the pupil entrance position of 2P3G lens group, set the pupil entrance position of the same inside-aperture lens which locates in the Lens 2(S2) or Lens 3(S1) surface. After simulation and analysis of ray tracing software, we get the best pupil entrance position of the lens to achieve the best efficiency and resolution. In addition, through the energy luminance analysis chart of stray light, comparison between this simulation and the actual test verifies that this design is consistent with the fact, so this method provides a reference for the future optical design and manufacture

    Ultra-Violet Treatment for Fermenting Low-Salt Soya Sauce

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    Low-salt soya sauce has become a market trend due to consumers' demand for a low sodium diet life. In tradition, a low-salt soya sauce (with salt concentration below 14.4%) is made from a high-salt one (18% salt concentration) through diluting or reducing the sodium content. The post processing deteriorates the quality of the soya sauce produce as some specific, beneficial chemical components are inevitably removed. In production of a native-born low-salt soya sauce, a key problem encountered is possible microbial contamination that easily develops in a low salt environment. In this study, we evaluated the effect of ultra-violet (UVC 254nm) irradiation on soya mash of 12% salt concentration fermented at 35°C. The ultra-violet treatment could effectively prevent the soya mash from microbial contamination

    Optical Design of Direct Projection Bicycle Light

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    Optical lighting systems usually demand specific illuminance distributions to comply with regulatory requirements for various applications. This study demonstrates an optical design of bicycle light integrated with a special Fresnel lens and a reflector. To enhance the light intensity, the proposed bicycle light adopts direct projection rather than reflection. The Fresnel lens is used to concentrate light and achieve the specific distribution of illuminance. The reflector provides a parabola reflective surface and reduces the divergence of light to greatly cast out parallel light, which improves the illuminance. For optimum case, the simulation is based on the total LED power of 180 lm, and the optical power is analyzed as 85 lm with a distance of 10 m away from the bicycle light. The illuminance distribution of bicycle light and cut-off line can meet the requirements of German StVZO regulations

    Reversible Data Hiding over Facebook

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    Facebook, the most popular Online Social Network (OSN), could be used as a platform to share secret messages through JPEG images online. However, due to the various lossy operations conducted over Facebook, the data embedded into the JPEG images can be easily destroyed, making the data extraction infeasible. More importantly, all these operations are carried out without users’ interference. In this paper, we first perform an in-depth investigation of the various lossy operations that Facebook applies to uploaded images. Based upon such prior knowledge, we propose a DCT-domain data hiding scheme that can effectively embed a large amount of data and successfully extract them out from the downloaded images, defeating the uncontrolled lossy operations. Compared with the state-of-the-art techniques, the proposed method offers much higher embedding capacity, and can extract the data successfully with very high probability. Furthermore, the restored image upon data extraction is of high quality, and the file size expansion is negligible. Extensive experimental results are provided to validate our findings

    Investigation of Cross-Coupling in Piezoelectric Transducer Arrays and Correction

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    Cross-coupling in piezoelectric transducer arrays is an undesirable phenomenon which decreases the performance of these devices. Indeed, when one element of a transducer is driven, it generates parasitic displacement fields at the radiating surfaces of the neighboring elements, which changes the directivity of the array. The objective of this paper is to investigate the cross-coupling effects on the piezoelectric transducer arrays performance and to propose solutions to reduce this parasitic phenomenon. In this context, it is demonstrated that a filling material having high mechanical losses contributes to the reduction of cross-coupling. In addition to this, a procedure of active cancellation of cross-coupling is successfully tested in the case of two transducer arrays vibrating in the transverse mode for the first prototype and thickness mode for the second one. Finally, the ability of the method is demonstrated even when the displacement at the radiating surface of the transducer array is not uniform

    Dynamic Poisson's Ratio and Modulus of Elasticity of Pozzolana Portland Cement Concrete

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    An experimental investigation was carried out to determine the dynamic Poisson's ratio and modulus of elasticity of pozzolana Portland cement concrete. Large numbers of concrete cubes were prepared and tested in the laboratory for investigation. The destructive and non-destructive tests were conducted on concrete cubes at different ages. The destructive test was conducted to obtain the compressive strength of concrete cubes. Ultrasonic pulse velocity of cube specimens was derived according to IS 13311 (Part 1) and the transit time of longitudinal and shear waves transmission was recorded. The recorded values are used to determine the dynamic values of Poisson's ratio and elastic modulus of concretes. Based on experimentally obtained data and analysis, a few relationships are proposed to correlate the water/cement ratio, Poisson's ratio, elastic moduli and compressive strength of concretes. Several interesting findings are observed from the correlations of the coefficients while analyzed by regression analysis. This study helps to determine the static properties of concrete from the dynamic ones

    Fire Resistant Study for Long Span Beams Made of FR 490 Steels

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    Building could be severely influenced by fire and it can be demolished so that the major structural elements such as columns and beams required to be coated by fire protection materials according to each condition. Especially, a steel framed building regarded as a weaken structures when the building is engulfed with a severe fire condition. Therefore, the fire resistant steel (FR 490) has been developed to improve the structural properties of an ordinary structural steels at high temperature. Generally, the fire resistance of structural beam built with a structural steel can be measured by horizontal furnace using a standard testing method by each nation’s standard. However, the real length of the beam showed the tendency longer than that of the horizontal furnace. Therefore, it is considered more important to know the real fire resistant performance of structural beams. In this paper, to evaluate the fire resistant performance of long span beams made of the FR 490, the fire engineering method is done using not only materials properties at high temperatures but a heat transfer, a stress theory. The results showed that as the length of beams are longer, the maximum load bearing capacities at high temperatures are lower and the deflections are increased
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