Showing papers in "Applied Mechanics and Materials in 2012"
TL;DR: In this paper, a new bat algorithm with mutation (BAM) is proposed to solve image matching problem, and a modification is applied to mutate between bats during the process of the new solutions updating.
Abstract: Due to shortcoming of traditional image matching for computing the fitness for every pixel in the searching space, a new bat algorithm with mutation (BAM) is proposed to solve image matching problem, and a modification is applied to mutate between bats during the process of the new solutions updating. This new approach can accelerate the global convergence speed while preserving the strong robustness of the basic BA. The realization procedure for this improved meta-heuristic approach BAM is also presented. To prove the performance of this proposed meta-heuristic method, BAM is compared with BA and other population-based optimization methods, DE and SGA. The experiment shows that the proposed approach is more effective and feasible in image matching than the other model.
104 citations
TL;DR: In this paper, the effect of the concentration of the cementation reagent on the performance of bio-mediated soil improvement was investigated, and the results showed that the calcite precipitation and shear strength improved with the increased concentration up to 0.5 M.
Abstract: Bio-mediated soil improvement is a relatively young technology in geotechnical engineering. The practical applications of the technique are still exposed to some uncertainties. This paper investigated the effect of the concentration of the cementation reagent on the performance of bio-mediated soil improvement. The shear strength, calcite content, pH, and ammonium content of the bio-mediated soil were measured under three concentrations of a cementation reagent, i.e. 0.25 M, 0.5 M, and 1 M. The results showed that the calcite precipitation and shear strength improved with the increased concentration of the cementation reagent up to 0.5 M. However, the improvement was retarded at higher concentration (i.e. 1.0 M). This is likely due to the inhibitory effect and halophilic characteristic of the bacteria used for the biocementation
46 citations
TL;DR: In this article, the Shannon's entropy approach was applied to assess the landslide susceptibility in Kalaleh township of Golestan province, Iran and a total of 82 landslide locations were identified primarily from aerial photographs and field surveys.
Abstract: In recent years, the growth of urban populations in hazardous areas has increased the impact of natural disasters in both developed and developing countries. The purpose of the current study is to assess the landslide susceptibility in Kalaleh township of Golestan province, Iran. In this study the Shannon’s entropy approach was applied. A total of 82 landslide locations were identified primarily from aerial photographs and field surveys. Then eighteen landslides conditioning factors were prepared in GIS. These landslide conditioning factors are: slope degree, slope aspect, altitude, plan curvature, profile curvature, tangential curvature, surface area ratio (SAR), lithology, land use, soil texture, distance from faults, distance from rivers, distance from roads, fault density, road density, topographic wetness index (TWI), stream power index (SPI), and sediment transport index (STI). Using these conditioning factors, landslide susceptibility index was calculated using Shannon’s entropy. For model validation, the results of the analyses were then compared with the field-verified landslide locations. Additionally, the receiver operating characteristics (ROC) curves for landslide susceptibility maps were drawn and the area under curve values was calculated. Verification results showed 82.15% accuracy. According to the results of the AUC (area under curve) evaluation, the map produced exhibits satisfactory properties.
45 citations
TL;DR: In this paper, a correct discrete-continual finite element method (DCFEM) of structural analysis based on precise analytical solutions of resulting multipoint boundary problems for systems of ordinary differential equations with piecewise-constant coefficients is presented.
Abstract: The distinctive paper is devoted to correct discrete-continual finite element method (DCFEM) of structural analysis based on precise analytical solutions of resulting multipoint boundary problems for systems of ordinary differential equations with piecewise-constant coefficients. Corresponding semianalytical (discrete-continual) formulations are contemporary mathematical models which currently becoming available for computer realization. Major peculiarities of DCFEM include uni-versality, computer-oriented algorithm involving theory of distributions, computational stability, optimal conditionality of resulting systems and partial Jordan decompositions of matrices of coeffi-cients, eliminating necessity of calculation of root vectors.
43 citations
Journal Article•
TL;DR: Wang et al. as mentioned in this paper investigated the emission inventory of criteria pollutants and green house gases of vessels in Shanghai port based on the bottom-up driving mode in 2010, and achieved the spatial distribution of pollutants and greenhouse gases based on 1 km × 1 km grids to meet the demands of the numeric modeling.
Abstract: The present paper attempts to introduce its study on the shipping pollutant emission inventory by taking Shanghai Port as a case sample.As is reported,Shanghai port succeeded in handling 29.07 million TEUs in 2010,thus ranking the world's busiest container-shipping champion in taking the place of Singaporean port.What is more,having accomplished a cargo shipment of 650 million tons in 2010,Shanghai port has been already honored as champion in this connection in the world for consecutive four years since 2006.Great as the advancement in vessel-shipment inventory may be,it is undeniable that,with the corresponding shipping emissions,which has in turn brought about tremendous environmental impact on the air and water,and even on the entire environment of the metropolis.And,consequently,it has become urgent to work out a reliable and up-to-date ship emission inventory and take immediate measures to limit and reduce the negative impact of shipping emission on the city.It is just for this urgent need that we have investigated the emission inventory of criteria pollutants and green house gases of vessels in the port based on the bottom-up driving mode in 2010.With a detailed survey made and activity analysis on the registration records,vessels types,tonnage distribution,driving modes,emission factors and fuel correction factors,we have worked out a total emission inventory of the vessels in and out Shanghai port by using the emission estimation methods.And,then,we have further divided the above said shipment emission into 9 types of vessels under 4 driving modes within the outer port and the inner river water-ways.Furthermore,we have achieved the spatial distribution of pollutants and green house gases based on the resolution of 1 km × 1 km grids to meet the demands of the numeric modeling,supported by the automatic identification system(AIS) in our paper.Thus,it can be followed that the total emissions of PM10,PM2.5,DPM,NOx,SOx,CO and HC by vessels were found to be equal to 4 600 ton,3 700 ton,4 400 ton,57.3 thousand ton,35.4 thousand ton,4 900 ton and 2 100 ton in 2010.The entire shipment was accounted to have produced green house gases with 2.885 5 million ton of CO2,100 ton of N2O and 40 ton of N2O.Comparing the total emission inventory in Shanghai,we have got to know that the share of the shipment contribution of the metropolis is equal to 12.0%,9.0% and 5.3% of the three key pollutants,including SO2,NOx and PM2.5.Of all the kinds of shipment,the ocean-going vessels are responsible for the total emission inventory with the shares of 12.0%,8.4% and 5.1%,respectively.
39 citations
TL;DR: A new strategy for optimal selection of the measurement configurations that essentially increases the efficiency of robot calibration is proposed, based on the concept of the robot test-pose and ensures the best compliance error compensation for the test configuration.
Abstract: The paper focuses on the calibration of elastostatic parameters of spatial anthropomorphic robots. It proposes a new strategy for optimal selection of the measurement configurations that essentially increases the efficiency of robot calibration. This strategy is based on the concept of the robot test-pose and ensures the best compliance error compensation for the test configuration. The advantages of the proposed approach and its suitability for practical applications are illustrated by numerical examples, which deal with calibration of elastostatic parameters of a 3 degrees of freedom anthropomorphic manipulator with rigid links and compliant actuated joints.
37 citations
TL;DR: In this article, the concept of pitch control has been implemented in the design of a small vertical-axis wind turbine and the benefits gained can be shown by the experimental and numerical results presented in this paper.
Abstract: The concept of pitch control has been implemented in the design of a small vertical-axis wind turbine. Benefits gained can be shown by the experimental and numerical results presented in this paper. As found, the method of variable pitch control outperforms the one of fixed pitch control. The present results show that the former can make remarkable improvement on the starting torque as well as the aerodynamic characteristics at low tip speed ratios.
36 citations
TL;DR: In this paper, the impedance spectroscopy method was used to characterize concrete specimens and track the changes in the concrete spectrum, and the results of this study are expected to provide information about the correlation between the n-factor and the concrete setting time.
Abstract: Concrete setting and hardening designate the concrete grade. The impedance spectroscopy method, as one of the non-destructive testing method group, was used to characterize concrete specimens and track the changes in the concrete spectrum. Variances in the tan δ (f) and Im Z(f) or Re Z(f) of the specimens under investigation have been observed. The specimen quality has been described by means of the loss type prevailing in the material. The results of this study are expected to provide information about the correlation between the n-factor and the concrete setting time.
34 citations
TL;DR: Simulation results show that the searching properties including searching efficiency, precision and robustness of IPSO algorithm are obviously better than that of the standard PSO(SPSO) algorithm.
Abstract: Particle swarm optimization (PSO) algorithm has the ability of global optimization , but it often suffers from premature convergence problem, especially in high-dimensional multimodal functions. In order to overcome the premature property and improve the global optimization performance of PSO algorithm, this paper proposes an improved particle swarm optimization algorithm , called IPSO. The simulation results of eight unimodal/multimodal benchmark functions demonstrate that IPSO is superior in enhancing the global convergence performance and avoiding the premature convergence problem to SPSO no matter on unimodal or multimodal high-dimensional (100 real-valued variables) functions.
33 citations
TL;DR: According to the published literature, the majority of system deployments resulted in significantly improved traffic operations compared to traditional time-of-day coordination plans, and ACS Lite was the lowest, while SCOOT was the highest.
Abstract: The primary objective of this paper is to provide a comprehensive overview of state-of-the-art and state-of-the practice of ATCSs. The review focuses on the following major aspects: (1) commonly deployed ATCSs in the U.S. and other countries; (2) features and functions of different ATCSs; and (3) evaluation studies based on field tests or laboratory simulation. According to the published literature, the majority of system deployments resulted in significantly improved traffic operations compared to traditional time-of-day coordination plans. Besides, based on the number of system deployments, SCOOT has the largest world-wide deployments, while SCATS has the largest U.S. deployments. Considering the costs of the deployment, ACS Lite was the lowest, while SCOOT was the highest.
32 citations
TL;DR: A new approach of soft material modeling for robotic manipulation which combines physical modeling and tracking of a deformable object using MRI system and two modeling methods which suit the problem: mass spring model and tensor mass model are presented.
Abstract: This article presents a new approach of soft material modeling for robotic manipulation which combines physical modeling and tracking of a deformable object. We discuss the construction of geometrical models using MRI system and how to overcome the problem of variability. The physical model focuses on meat/muscles deformation. We introduce the principal criteria for choosing most appropriate models and discuss two modeling methods which suit our problem: mass spring model and tensor mass model. The introduction of anisotropy in these models allows results to be more realistic but evolves an increasing of computing time.
TL;DR: Using higher-order terms of the Williams expansion is necessary for assessment of fracture behavior of quasi-brittle materials, and extensive analyses have been performed in order to summarize recommendations regarding the mesh sensitivity, boundary conditions influence, etc.
Abstract: Using higher-order terms of the Williams expansion is necessary for assessment of fracture behavior of quasi-brittle materials. Multi-parameter fracture mechanics enables more accurate determination of the stress/displacement field even in a larger distance from the crack tip, thus the extended zone with non-elastic behavior typical for this kind of material can be well described. The so-called over-deterministic method (ODM) seems to be a suitable tool for the higher-order terms coefficients calculation, but its utilization exhibits some limitations. Therefore, extensive analyses have been performed in order to summarize recommendations regarding the mesh sensitivity, boundary conditions influence, etc. List of pieces of advice and author’s experiences presented in the end of this work should contribute to more accurate and effective utilization of the ODM.
TL;DR: In this paper, a locally available nanosilica is used on mortar and concrete thereby limiting the use of commercial, regular silica fume combined with the locally produced nano-silica.
Abstract: The development of construction materials technology, particularly concrete is growing very rapidly in the presence of nanotechnology. One material that deserves the attention of researchers is nanosilica. Silica has been used on concrete, starting from silica sand as a filler to microsilica (silica fume) as a reactive pozzolan. Based on previous research, silica fume is proven effective to improve the mechanical properties and durability of concrete. A novel nanotechnological process allows producing amorphous nanosilica with high reactivity from locally available silica sand. In this study a locally available nanosilica is used on mortar and concrete thereby limiting the use of commercial nanosilica materials from semiconductor industry waste. To obtain sustainable concrete, the mix is design to have high strength as well as low permeability using as much possible local sources. This study also make use of commercial, regular silica fume combined with the locally produced nanosilica. The results show that combined use of nanosilica with silica fume can increase the compressive strength and durability.
TL;DR: In this article, numerical simulations were performed for phase change material (PCM) melting in annulus while the inner pipe has two or four longitudinal fins and the results compared with inner bare tube, the authors concluded that melting performance of PCM can be significantly improved by applying longitudinal fins on the inner tube.
Abstract: This paper presents numerical investigations on melting of phase change material using paraffin wax inside a double pipe heat exchanger Numerical simulations are performed for melting of phase change material (PCM) in annulus while the inner pipe has two or four longitudinal fins and the results compared with inner bare tube The aim of this study is to understand the PCM melting behaviors by observing the natural convection currents movement and melting fronts formation It is concluded that melting performance of PCM can be significantly improved by applying longitudinal fins on the inner tube
TL;DR: In this paper, wire electrical discharge machining (WEDM) is adopted in machining of commercially pure titanium (Grade-2) during experiments, parameters such as Pulse on time, Pulse off time, Peak current, Spark Gap set Voltage, Wire Feed and Wire Tension were changed to explore their effect on the cutting rate, gap current and surface roughness of the machined specimens.
Abstract: Titanium is present in the earth’s crust at a level about 0.6% and is therefore the fourth most abundant structural metal after aluminum, iron, and magnesium. High strength, low density, and excellent corrosion resistance are the main properties that make titanium attractive for a variety of applications. The major application of the material is in the aerospace industry, both in airframes,engine components,steam turbine blades, superconductors, missiles etc. or corrosion resistance, for example marine services, chemical, petrochemical, electronics industry, biomedical instruments etc.In this study, wire electrical discharge machining (WEDM) is adopted in machining of commercially pure titanium (Grade-2). During experiments, parameters such as Pulse on time, Pulse off time, Peak current, Spark Gap set Voltage, Wire Feed and Wire Tension were changed to explore their effect on the cutting rate, gap current and surface roughness of the machined specimens. The ranges of process parameters for the experiments were decided on the basis of literature survey and the pilot experiments conducted using one factor at a time approach(OFTA). It is found that the intensity of the process energy does affect the cutting rate, gap current and surface roughness as well as, the wire speed, wire tension and dielectric fluid pressure not seeming to have much of an influence.
TL;DR: In this article, the characteristic of intergranular corrosion on austenitic stainless steel is presented and the effective measures to prevent intergranule corrosion are proposed, as well as the evaluation methods of sensitivity to intergranularity corrosion are introduced.
Abstract: In the paper, the characteristic of intergranular corrosion on austenitic stainless steel is presented. The principles and the influencing factors of intergranular corrosion are analyzed in detail. Furthermore, the effective measures to prevent intergranular corrosion are proposed. Finally, the evaluation methods of sensitivity to intergranular corrosion are introduced.
TL;DR: In this article, the impact penetration and flexural (three point bending) test were conducted on composite sample and Morphological analysis was performed using Scanning Electron Microscope (SEM).
Abstract: Natural fibre has become the subject of interest for research and development by various organizations due to its biodegradable and competitive mechanical properties. However most of the researchers are focusing on random orientation and compressed mat with only little researches concerned with woven or textile structure. This research work involved with mechanical analysis of woven natural fibres composite specifically coir and kenaf natural fibres. Plain woven coir and kenaf were produced from their yarns using self designed weaving device. The woven fibres were then converted as reinforcement in composite. Woven composite was prepared using manual hand lay up technique couple with vacuum bagging. Impact penetration and flexural (three point bending) test were conducted on composite sample. Morphological analysis was performed using Scanning Electron Microscope (SEM). From the results obtained, dry woven coir composite displayed better mechanical properties for both impact and flexural properties compared to kenaf composite. Warp direction of coir composite and kenaf composite showed a better flexural strength compared to weft composite direction. Coir yarn with slight lower fineness value than kenaf yarn had contributed to the higher fibre density in woven structure. The structure used as composite reinforcement in turn produced better mechanical properties.
TL;DR: Improved SO-PMI does more effective on weight calculation and sentiment lexicon building and would be effective to use ((SO-A) and (SO-P) as text sentiment classifiers.
Abstract: Considering user behavior, this paper has built a Chinese sentiment lexicon based on improved SO-PMI algorithm. Sematic lexicons were used to classify the sentiment of the collected Chinese hotel reviews. The experiment has compared the feature extraction between CHI and sentiment lexicons to find out different classification performances. The results indicate that feature extraction based on sentiment lexicon gains higher F1. The performance of classification method “Basic Semantic Lexicon + BOOL + NB” gains 92.40% of F1. Based on different sentiment lexicons, the experimental results shows that (SO-A) and (SO-P) is slightly better than NB classifier. Therefore, it would be effective to use ((SO-A) and (SO-P) as text sentiment classifiers. The experiment also finds out the method “Hotel Reviews Semantic Lexicon using improved SO-PMI algorithm +((SO-A)” gains the highest F1 which is 92.84%. The results reveal that improved SO-PMI does more effective on weight calculation and sentiment lexicon building.
TL;DR: In this article, the feasibility of dissimilar welding between AISI 304 stainless steel and carbon steel plates with the thickness of 15 mm was studied, and the processes applied in this work were gas tungsten arc welding and shield metal arc welding (SMAW).
Abstract: . This work studied the feasibility of dissimilar welding between AISI 304 stainless steel and AISI 1020 carbon steel plates with the thickness of 15 mm. The processes applied in this work were gas tungsten arc welding (GTAW) and shield metal arc welding (SMAW). Microstructure of weld metal produced by GTAW consists of delta ferrite network in austenite matrix, while the dendrite of delta ferrite finely distributed in austenite matrix was found in the weld produced by SMAW. Hardness values of weld metals produced using these two techniques were superior to those of stainless steel and carbon steel base metals respectively. Weld metals produced by these two processes were qualified under tension and bending. This was justified by the result that the failed part after transverse tensile test was on carbon steel, and no crack was found in weld metal after U-shape bending. Impact test exhibited higher toughness of weld metal produced by GTAW than that produced by SMAW. This might be from microstructure of the former weld as network of delta ferrite in austenite matrix which might help absorb impact energy. Pitting corrosion potential of weld metal produced by GTAW was higher than that produced by SMAW and stainless steel base metal respectively. In the aspect of mechanical and corrosion properties of the weld, GTAW was considered as a promising process that could be used for dissimilar welding between these two metals.
TL;DR: Based on the unified solution of shear strength in terms of double stress state variables for unsaturated soils, whilst considering the effect of the intermediate principal stress rationally, this paper developed a unified solution based on Coulomb's active earth pressure.
Abstract: Based on the unified solution of shear strength in terms of double stress state variables for unsaturated soils, whilst considering the effect of the intermediate principal stress rationally, the unified solution of Coulomb’s active earth pressure for unsaturated soils without cracks is developed. Comparability of the solution is analyzed and influencing characteristic of each factor is obtained. The research result indicates that: the intermediate principal stress and matric suction have obvious impacts on Coulomb’s active earth pressure for unsaturated soils; Coulomb’s active earth pressure has been decreasing until zero with the increase of unified strength theory parameter and matric suction; Coulomb’s active earth pressure increases with the increase of grading angle of retaining wall and slop angle of backfill, but decreases with the increase of matric suction, effective internal friction angle and matric suction angle, while external friction angle has no obvious influence. The proposed unified solution of Coulomb’s active earth pressure enjoys a wider application, and unified solution of Rankine’s active earth pressure is just the special case. The results are of great significance to soil pressure determination such as slope and foundation pit, and to retaining structures design.
TL;DR: In this paper, the effects of swirl velocity on flow fuel-air premixing mechanism and burning process in diesel combustion that strongly affects the exhaust emissions are discussed in detail, and the authors investigated diesel combustion fundamentally using a rapid compression machine (RCM) together with the schlieren photography and direct photography methods.
Abstract: Diesel engines generate undesirable exhaust emissions during combustion process and identified as major source pollution in the worldwide ecosystem. To reduce emissions, the improvements throughout the premixing of fuel and air have been considered especially at early stage of ignition process. Purpose of this study is to clarify the effects of swirl velocity on flow fuel-air premixing mechanism and burning process in diesel combustion that strongly affects the exhaust emissions. The effects of physical factors on mixture formation and combustion process to improve exhaust emissions are discussed in detail. This study investigated diesel combustion fundamentally using a rapid compression machine (RCM) together with the schlieren photography and direct photography methods. RCM was used to simulate actual phenomenon inside the combustion chamber with changing design parameter such as swirl velocity, injection strategies and variable nozzle concept. The detail behavior of mixture formation during ignition delay period was investigated using the schlieren photography system with a high speed digital video camera. This method can capture spray evaporation, spray interference and mixture formation clearly with real images. Ignition process and flame development were investigated by direct photography method using a light sensitive high-speed color digital video camera. Moreover, the mechanism and behavior of mixture formation were analyzed by newly developed image analysis technique. Under high swirl condition, the ignition delay is extended, the higher heat losses and unutilized high-density oxygen associated with slower initial heat recovery begins might be the explanation for the longer combustion duration, reductions of pick heat release and promote combustion and soot oxidation. The real images of mixture formation and flame development reveal that the spray tip penetration is bended by the high swirl motion, fuel is mainly distributed at the center of combustion chamber, resulting that flame is only formed at the center region of the combustion chamber. It is necessary for high swirl condition to improve fuel-air premixing.
TL;DR: In this article, the authors describe the design process and features of a wind tunnel model used for research into a novel aerodynamic flow control technique, and choose an additive manufacturing technique as the most suitable for the rapid, accurate and simplest fabrication process for the model.
Abstract: Rapid prototyping techniques are ideally suited to the manufacture of aerodynamics research models as these items usually consist of highly complex 3 Dimensional (3D) forms. The fabrication of complex curvatures on traditional Computer Numerical Control (CNC) machines often requires the production of additional tooling supports to allow for full machining of all surfaces. Such a necessity often results in extra cost and fabrication time, as well as a potential loss in accuracy due to any repositioning required to allow machining of internal and external features. It is often necessary to divide the model into additional sections to allow for the machining of internal features which can cause issues with mismatching of adjacent surfaces. The inclusion of small or complex internal features and hollow sections may be problematic if not impossible. In contrast, many rapid prototyping techniques eliminate most of these manufacturing issues due to the additive nature of modern 3D printing processes. Popular techniques for the rapid prototyping of polymers include Selective Laser Sintering (SLS), Fused Deposition Modeling (FDM) and stereolithography. The basic technique reduces a 3D object into a series of thin 2D slices. The 2D slices are then “printed” vertically in succession to produce the final 3D item The “slicing” technique is readily compatible with the formation of complex 3D curvatures as well as internal and hollow features. In addition, any required tooling supports are produced simultaneously with the desired item, which greatly reduces processing time and loss of accuracy due to part repositioning. The necessity to produce a model from multiple sections to allow access for machining of internal features can in many cases be reduced significantly. The characteristics intrinsic to many modern 3D printing techniques are greatly beneficial for the production of complex wind tunnel models made from polymer. The current work describes the design process and features of a wind tunnel model used for research into a novel aerodynamic flow control technique. An additive manufacturing technique was chosen as the most suitable for the rapid, accurate and simplest fabrication process for the model.
TL;DR: A hierarchical architecture for CPSs is proposed, and the particle swarm optimization (PSO) algorithm is applied to solve the considered constraint model, and some instructive proposals for promoting QoS are outlined.
Abstract: Cyber-physical systems (CPSs) perfectly integrate computing with physical processes, and the emergence of CPSs has attracted significant interest in recent years. In order to fully utilize system resource and improve quality of service (QoS), the innovative resource management method for CPSs is essential. According to a representative case of CPSs (e. g., unmanned vehicle with wireless sensor network navigation), we propose a hierarchical architecture for CPSs, and further establish a system performance optimization model with resource constraints. The particle swarm optimization (PSO) algorithm is applied to solve the considered constraint model. The simulation experiment results verify the efficiency of PSO algorithm, and some instructive proposals for promoting QoS are also outlined.
TL;DR: In this article, the results of machinability tests on new austenitic stainless steels X01Cr14Ni9TiN were presented, and the results were evaluated under cutting conditions (cutting speed in interval vc=40-60 m/min, depth of cut ap=2.5 mm and feed f=0.01-0.12 mm per rev.).
Abstract: This article presents the results of experiments that concerned on the surface roughness quality by drilling of a new Extra Low Carbon (ELC) austenitic stainless steel X01Cr14Ni9TiN. This article presents conclusions of machinability tests on new austenitic stainless steels X01Cr14Ni9TiN. The results of cutting zone evaluation under cutting conditions (cutting speed in interval vc=40-60 m/min, depth of cut ap=2.5 mm and feed f=0.01-0.12 mm per rev.).
TL;DR: In this article, the authors present a strategy for the maximization of the output power of photovoltaic (PV) systems under non homogeneous solar irradiation by means of automatic reconfiguration of the PV arrays layout.
Abstract: This paper presents a strategy for the maximization of the output power of photovoltaic (PV) systems under non homogeneous solar irradiation by means of automatic reconfiguration of the PV arrays layout. The innovation of the proposed approach is the employment of a simple Dynamic Electrical Scheme (DES), allowing a large number of possible modules interconnection, to be installed between the PV generator and the inverter. The models of the PV generator and of the DES have been realized and simulated with Simulink (Dynamic System Simulation for MATLAB). The attained experimental results appear to be quite interesting in terms of the attainable benefit in power and thus energy terms. The limited calculation times of the reconfiguration algorithm allows the application of the DES for the real time adaptation of the configuration to the changing weather conditions or other causes of non-uniform solar irradiation. Moreover, the results confirm that, in case of non uniform solar irradiation, this approach allows to attain considerably much better results than those attainable with a static configuration.
TL;DR: In this article, the authors studied the tool wear behavior of Si3N4 cutting tool with the aim of finding the optimum cutting conditions for both dry and wet machining of T6061 Aluminium alloy.
Abstract: Dry machining is an eco-friendly machining process and its importance in the manufacturing industries should be taken seriously. Machining without the use of any cutting fluid is becoming increasingly more popular due to concerns regarding the safety of the environment and reducing cost. Dry and wet turning of T6061 aluminium alloy was performed on a lathe by using Silicon Nitride (Si3N4) inserts as the cutting tool. Tool wear behaviour of Si3N4 cutting tool were studied with the aim of finding the optimum cutting conditions for both dry and wet machining. Machining was performed at four different cutting speeds; 292, 388, 518 and 689 m/min using two different cutting parameters (feed rate, f = 0.2 mm/rev, depth of cut, d = 0.1 mm and f = 0.4 mm/rev, d = 0.2 mm). Material removal rate (MRR) was also obtained and the temperature at the tool-chip interface were measured using an infrared (IR) thermometer as to see the effect of temperature rise during machining. Dry machining with smaller cutting parameters resulted in lower wear rates by 37 to 48% for all four cutting speeds. Nevertheless, reduction of wear rate by 38 to 57% was found from wet machining. The optimum cutting speed for both dry and wet machining of T6061 aluminium alloy using Si3N4 cutting tool was found to be 518 m/min for both cutting parameters. However, the optimum cutting parameters are apparently with the feed rate of 0.4 mm/rev and depth of cut of 0.2 mm. At the optimum cutting speed, the tool tip temperature for dry machining was higher than wet machining by 40 and 51% for f = 0.2 mm/rev and f = 0.4 mm/rev respectively. Dry machining of T6061 Aluminium alloy can be more suitable particularly at higher cutting speed with interrupted cutting operations.
TL;DR: The proposed Support Vector Machine (SVM) regression has been applied in Baishuihe landslide in Three Gorges Reservoir Area, China and indicates SVM regression is reliable to calculate the displacement factors and can be used in short term prediction of landslide monitoring data.
Abstract: Time series analysis has the ability to forecast the evolve trend of complex systems, which has been the issue in the research of landslide displacement dynamic forecasting. The Support Vector Machine (SVM) regression, we proposed, has been applied in Baishuihe landslide in Three Gorges Reservoir Area, China. The Oracle Data Mining (ODM) PL / SQL API have been introduced to build the SVM regression model for data mining process. The data was divided into two parts, wherein the first 36 months data used for training, and the other 6 months data used for validation. The results show that the error rate of the previous 5 was controlled within 8% and the accuracy of the 6th is 84.1%, which indicates SVM regression is reliable to calculate the displacement factors and can be used in short term prediction of landslide monitoring data.
TL;DR: In this paper, the concept and design procedure of ASCE7 and compared the seismic analysis results of AS CE7 and GB 50011-2010 through a project example, the similarities and differences of American code and Chinese code on seismic design are summarized.
Abstract: Nowadays the design becomes more and more international. In order to effectively meet this trend, it is necessary to understand the similar or different concept and application of American code and Chinese code on seismic design. This article introduces the concept and design procedure of ASCE7 and compares the seismic analysis results of ASCE7 and GB 50011-2010 through a project example. The similarities and differences of American code and Chinese code on seismic design are summarized.
TL;DR: The results of the tests indicated that the desert sand could be used as a fine aggregate in concrete for general civil engineering as discussed by the authors, which provided references for high strength concrete preparation in these regions.
Abstract: The desert sand from Maowusu sandy land is very fine aggregate. Currently, there are no national specifications concerning the application of desert sand with very fine grain. To apply the desert sand to concrete in civil engineering, concrete specimens made of the desert sand had been tested in order to clarify its engineering characteristics. On the basis of determined chemical composition and physical characteristics of the desert sand, the mechanical properties of concrete made of fine aggregate from Maowusu sandy land were investigated. The results of the tests indicated that the desert sand could be used as a fine aggregate in concrete for general civil engineering. At the same time, the desert sand was used to confect high strength concrete, the strength and workability of which met general engineering requirement, which provided references for high strength concrete preparation in these regions
TL;DR: Embedded Inertial Navigation System designed and manufactured by the Department of Automatic Control and Robotics in Silesian University of Technology, Gliwice, Poland is presented, currently one of the smallest in the world.
Abstract: This paper presents Embedded Inertial Navigation System designed and manufactured by the Department of Automatic Control and Robotics in Silesian University of Technology, Gliwice, Poland. Designed system is currently one of the smallest in the world. Within it there is implemented INS-GPS loosely coupled data fusion algorithm and point-to-point navigation algorithm. Both the algorithms and the constructed hardware were tested using two unmanned ground vehicles varying in size. Acquired results of those successful tests are presented.