Taiwan Association of Engineering and Technology Innovation: E-Journals
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Scalable Load Balancing Approach for Cloud Environment
Get PDFCloud computing is a combination of parallel and distributed system which aims at effective resource utilization, providing uninterrupted services all the time which adapts itself with varying number of users without much capital investment. Ubiquitous, scalability and elasticity are some of the important features of cloud computing. To maintain essential characteristics, there is a need of mechanism which distributes the load efficiently among the available resources. Load balancing means the distribution of tasks among different available resources so that no one is over or under-utilized. Scalable, adaptable, efficient and reliable are some of the desirable features of a load balancing approach.In this paper, authors have proposed a new load balancing approach named “Weighted Biased Random Walk” for the cloud environment using the concept of biased random walk. Weighted biased random walk approach has been analytically & experimentally analyzed. It has been compared with other load balancing approaches based on biased random walk found in literature. It has been found that weighted biased random walk approach is self-adjustable, distributed, dynamic, scalable and efficient in nature. It outperforms the other load balancing approaches based upon biased random walk. Collective presence of all the desirable features makes the weighted biased random walk approach perfect load balancing approach for the cloud environment
Segmented Compression Molding for Composite Manufacture
Get PDFIn the present study a new technique of vacuum assisted resin transfer molding (VARTM), called segmented compression molding (SCM), is proposed to improve filling process. In the method, a double-bag is placed between the upper mold and the cavity, and each bag is controlled individually. Through the vacuum pulling the double-bag upward, resin is easily infused into the loose preform. After the completion of resin infusion, the resin inlet is closed. The vacuum on the bags are sequentially released to atmospheric pressure, the inflated bags squeeze the surplus resin from the wetted preform toward dry loose preform and the filling process is thus reduced. This study is to introduce the SCM, model the filling process and explore the surface quality of the SCM parts. Results show that the SCM filling process is decreased by using a high initial cavity thickness. As compared with transfer resin transfer molding (RTM) and typical VARTM, SCM can reduce the filling process in the work. The surface roughness of SCM part approximates that of VARTM, but it is much inferior to that of RTM
Applications of Thermal Images for Monitoring Surficial Temperature Changes of Naked Slope
Get PDFGlobal climate change causes increases in the torrential rainfall brought by typhoons and the monsoon in Taiwan. Torrential rain in turn causes landslides, debris flows, and the formation of earth dams. Most dams were formed in remote mountainous areas and are difficult to reach for safety evaluation at the beginning of their formation. A long distance and non-destructive testing methodology is necessary for evaluating the safety of landslide dams. This study used an infrared imager for monitoring naked slopes. The thermography can detect surficial radiation temperature changes in the slope to locate potential unstable areas for further monitoring. This study proposes radiation temperature change (T) per unit of time (Δt) as an index (T /Δt) for nondestructive monitoring. The index was used for monitoring and analysis of artificial earth dams constructed at Huishun farm in Nantou County. The results of the analysis show that the failure zone of the artificial dam exhibited the greatest change in the index and the potential failure mode could be predicted once the dam breached. The proposed model could be used for potential unstable slope monitoring
The Influence of Density of the Materials and Body Mass Index on the Elderly’s Sleep Efficiency
Get PDFInsomnia is a common problem among the elders and it directly affects their health. The mattress is one factors influencing sleeping efficiency. The developed pressure at the sleeping surface during sleeping will to cause body discomfort, leading to sleep problem. The developed pressure depends on the density of bedding materials and body mass. The present research aims to study the effects of the mattress density and body mass on the elderly sleep efficiency. The sleep data was collected from 6 volunteers: 3 male and 3 female at the age group of 60 – 79 years. The experiment was done on mattresses with densities of 24.6 and 60 kg/m3 and 4-inch thickness. The volunteers randomly slept on each mattress for three nights. Sleep data was recorded by sleep tracker (Jawbone up24), calibrated with Polysomnography. The study revealed that sleep efficiency on the 60 kg/m3 density mattress was more than 90 percent while those on the 24.6 kg/m3 density mattress were in the range of 78-84 percent. Moreover, sleep efficiency of the volunteers with the body mass index of 22.22 - 23.74 kg/cm2 was significantly different from those of volunteers with the body mass index of 24.61-24.92 kg/cm2 when they slept on the 24.6 kg/m3 density mattress. Additionally, the pressure test revealed that a pressure at shoulder may affect sleep efficiency
Investigation of a Ball Screw Feed Drive System Based on Dynamic Modeling for Motion Control
Get PDFThis paper examines the frequency response relationship between the ball screw nut preload, ball screw torsional stiffness variations and table mass effect for a single-axis feed drive system. Identification for the frequency response of an industrial ball screw drive system is very important for the precision motion when the vibration modes of the system are critical for controller design. In this study, there is translation and rotation modes of a ball screw feed drive system when positioning table is actuated by a servo motor. A lumped dynamic model to study the ball nut preload variation and torsional stiffness of the ball screw drive system is derived first. The mathematical modeling and numerical simulation provide the information of peak frequency response as the different levels of ball nut preload, ball screw torsional stiffness and table mass. The trend of increasing preload will indicate the abrupt peak change in frequency response spectrum analysis in some mode shapes. This study provides an approach to investigate the dynamic frequency response of a ball screw drive system, which provides significant information for better control performance when precise motion control is concerned
Oxidation of Titanium and Ti/(TiB+TiC) Composite
Get PDFTitanium and titanium matrix composite reinforced with 10 vol. %(TiB+TiC) (10TMC) were oxidized at 700, 800 and 900 oC for 30, 50 and 70 h, and their oxidation behavior was studied. Oxidation of Ti and 10TMC in air led to the formation of rutile-TiO2 without any other oxides. The oxide scale thickened with an increase in the oxidation time and temperature. Significant growth of the rutile oxide caused thermal stresses which generated during oxidation and voids formed at the scale/matrix interface, and the oxide scales were susceptible to cracking.
Harvesting Atmospheric Ions Using Surface Electromagnetic Wave Technologies
Get PDFFor the first time, this paper discloses the use of flowing water for capturing atmospheric ions into a DC electricity. The proposed methodology can be employed to neutralize the positively charged pollutants in air, which are believed to be harmful to our health. Methodology: Atmospheric ions can be collected by a negatively charged antenna which comprises a dielectric layer sandwiched between a top aluminium layer and a bottom lead plate. The top aluminium layer is used to collect the ambient protons, whilst the bottom lead plate is negatively charged by a negative static electricity extracted from flowing water. The voltage has been measured between the top aluminium layer and the bottom lead plate with and without any sunlight. Results: Without any UV light or other electromagnetic disturbance, the generated voltage has rapidly increased from 200 mV to 480 mV within 5 seconds if the bottom lead plate is connected to the negative ion source. Without the negative ion source, however, the output voltage fell to around 10 mV and any significant voltage rise can be observed even in the presence of an UV light. Conclusions: Capturing atmospheric ions is technically feasible. Measured results suggest that, when used in conjunction with a negative ion source, the proposed device can harvest atmospheric ions without any UV light
Numerical Modeling of a Jet Ignition Direct Injection (JI DI) LPG Engine
Get PDFThe paper presents indirectly validated simulations of the operation of a LPG engine fitted with Direct Injection (DI) and Jet Ignition (JI). It is demonstrated that the engine may have diesel like efficiencies and load control by quantity of fuel injected. As the liquid propane quickly evaporates after injection in the main chamber, the main chamber mixture may be much closer to stoichiometry than a diesel for a better specific power at low engine speeds. This design also works at the high engine speeds impossible for the diesel, as combustion within the main chamber is controlled by the turbulent mixing rather than the vaporization and diffusion processes of the injected fuel of the diesel.
Wireless Low Power Light Emitting Device with RGB LED
Get PDFColor therapy is a type of alternative medicine. It utilizes the emission of a specific wavelength of light to treat diseased areas. This study presents a wireless, low-power light-emitting device with RGB LED to conduct color therapy. The device is small-sized, adhesive to the skin, and without a tether line for power or communication. Aided by the property of skin adhesiveness, the device provides a therapeutic effect comparable to that of available devices, over a short radiation distance and consumes low power. The therapeutic dosage parameters including color wavelength combination, LED brightness, and illumination time can be regulated through the smartphone application. The wavelength consistency over intensities and the intensity accuracy were validated. With effective calibration, the emission of light by the LED can be effectively regulated to ensure therapeutic effects
A Study on the Burn Pattern Experiments in Structure Fire
Get PDFThe fire has created tremendous damage, yet skilled fire investigators can read the fire patterns left by the fire. Through the fire patterns interpretation and analysis, fire investigators should be able to determine exactly how and where the fire or explosion started. Fire patterns can help the fire investigator trace fire movement back to the point of origin. The origin and cause investigation for is attempting to determine the first material ignited, the source of ignition, and how the two brought together to cause the ignition. The investigators should read the fire scene to establish the area of origin. In this study, through burn pattern experiments, fire behavior in the compartment, fire pattern formation mechanism, fire patterns reproducibility, fire patterns persistence through flashover and full room involvement condition, fire scene reconstruction for fire origin determination, and other fire pattern’s temperature will be discussed and analyzed in depth. Burn test was conducted to recognize and analyze fire patterns created in the phase of pre flashover or post flashover in the compartment (container house). In addition, fire pattern experiments are designed to test combustible material, including polyurethane foam with a lower thermal inertia or wooden chair with a higher thermal inertia. During these experiments, through the thermocouple fire pattern’s temperature will be measured in the stage of pre flashover or post flashover.