bluuebunny/crossref_metadata_2025 huggingface dataset:
Big Data and Web Intelligence
Authors: Pliego Alberto , Márquez Fausto Pedro García
Published: September 2015

The growing amount of available data generates complex problems when they need to be treated. Usually these data come from different sources and inform about different issues, however, in many occasions these data can be interrelated in order to gather strategic information that is useful for Decision Making processes in multitude of business. For a qualitatively and quantitatively analysis of a complex Decision Making process is critical to employ a correct method due to the large number of operations required. With this purpose, this chapter presents an approach employing Binary Decision Diagram applied to the Logical Decision Tree. It allows addressing a Main Problem by establishing different causes, called Basic Causes and their interrelations. The cases that have a large number of Basic Causes generate important computational costs because it is a NP-hard type problem. Moreover, this chapter presents a new approach in order to analyze big Logical Decision Trees. However, the size of the Logical Decision Trees is not the unique factor that affects to the computational cost but the procedure of resolution can widely vary this cost (ordination of Basic Causes, number of AND/OR gates, etc.) A new approach to reduce the complexity of the problem is hereby presented. It makes use of data derived from simpler problems that requires less computational costs for obtaining a good solution. An exact solution is not provided by this method but the approximations achieved have a low deviation from the exact.
The Politics of Access to Information
Authors: Virkar Shefali
Published: September 2015

Over the last few decades, unprecedented advances in communications technology have collapsed vast spatial and temporal differences, and made it possible for people to form connections in a manner not thought possible before. Centred chiefly on information, this revolution has transformed the way in which people around the world think, work, share, and communicate. Information and Communication Technologies (ICTs) promise a future of a highly interconnected world, wherein action is not limited by physical boundaries, and constrained physical space is replaced by a virtual ‘cyberspace' not subject to traditional hierarchies and power relations. But is the promise of ICTs chimerical? To tackle these issues, central to the global policy debate over the potential development contributions of Information and Communication Technologies, and to examine whether and the extent to which disparities in access to ICTs exist, this book chapter provides a demonstration of the ways in which ICTs may be used as tools to further global economic, social, and political advancement, to shape actor behaviour, and to enhance institutional functioning; particularly in the Third World.
Modeling Big Data Analytics with a Real-Time Executable Specification Language
Authors: Khwaja Amir A.
Published: September 2015

Big data explosion has already happened and the situation is only going to exacerbate with such a high number of data sources and high-end technology prevalent everywhere, generating data at a frantic pace. One of the most important aspects of big data is being able to capture, process, and analyze data as it is happening in real-time to allow real-time business decisions. Alternate approaches must be investigated especially consisting of highly parallel and real-time computations for big data processing. The chapter presents RealSpec real-time specification language that may be used for the modeling of big data analytics due to the inherent language features needed for real-time big data processing such as concurrent processes, multi-threading, resource modeling, timing constraints, and exception handling. The chapter provides an overview of RealSpec and applies the language to a detailed big data event recognition case study to demonstrate language applicability to big data framework and analytics modeling.
The Effectiveness of Big Data in Social Networks
Authors: Nyunt Khine Khine , Zaman Noor
Published: September 2015

In this chapter, we will discuss how “big data” is effective in “Social Networks” which will bring huge opportunities but difficulties though challenges yet ahead to the communities. Firstly, Social Media is a strategy for broadcasting, while Social Networking is a tool and a utility for connecting with others. For this perspective, we will introduce the characteristic and fundamental models of social networks and discuss the existing security & privacy for the user awareness of social networks in part I. Secondly, the technological built web based internet application of social media with Web2.0 application have transformed users to allow creation and exchange of user-generated content which play a role in big data of unstructured contents as well as structured contents. Subsequently, we will introduce the characteristic and landscaping of the big data in part II. Finally, we will discuss the algorithms for marketing and social media mining which play a role how big data fit into the social media data.
Prescheduled Controller for Split Unit Air Conditioner Reduce Energy Consumption
Authors: Salauddin Syazwi Amzar , de Silva Liyanage C. , Petra Iskandar
Published: September 2015

Air conditioners are one of the highest power consuming devices in houses or industrial buildings. Most buildings require air conditioner to make offices, classrooms, public areas or rooms to meet the required thermal comfort. Split unit type air conditioners are widely used in Negara Brunei Darussalam and other ASEAN countries. Currently, prescheduled controllers for split-unit air conditioners are not available in the market. In order to reduce air conditioner power consumption, study have been done to measured energy saving by controlling air conditioning using prescheduled controller that designed which is suitable for fixed operation hours example offices, schools, shops and others. Result showed that average percentage of power saving using a prescheduled controller can be as high as 40%.
Trajectory Controllability of Semilinear Systems with Delay in Control and State
Authors: Klamka Jerzy , Ferenstein Elżbieta , Babiarz Artur , Czornik Adam , Niezabitowski Michał
Published: September 2015

In this paper we consider the finite-dimensional dynamical control system described by scalar semilinear ordinary differential state equation with variable delay. The semilinear state equation contains both pure linear part and nonlinear perturbation. We extend the concept of controllability on trajectory controllability for systems with point delay in control and in nonlinear term. Moreover, we present remarks and comments on the relationships between different concepts of controllability. Finally we propose the possible extensions.
Providing Security of Vital Data for Conventional Microcontroller Applications
Authors: Akdemir Bayram , Üzülmez Hasan
Published: September 2015

Microcontrollers are widely used in industrial world, and almost all kind of devices were based on microcontroller to achieve high flexibility and abilities. All microcontrollers have nonvolatile and volatile memories to execute the software. During the running, microcontroller calculates many variables and records them to any non-volatile memory to use later. After re-energizing, microcontroller takes the data calculated before the power off and executes the program. In case of any electrical writing error or any power loss during the writing procedure, un-written memory blocks or any un-written data leads to malfunctions. Proposed method uses a gray code based signed two memory blocks to secure the memory reserved for data. Microcontroller uses these memory blocks in alternately. Even if microcontroller has no any real-time ability, gray code provides a guarantee which block is written in last. For every re-starting microcontroller dos not lose the data. In case of any reading problem during the starting, microcontroller has two chances to decide the action. One is to start with default values and the other is to start with the previous data. This study is tested at elevator applications not to lose position and vital values.
An Affine Parameter Dependent Controller of an Helicopter for Various Forward Velocity Conditions
Authors: Şahin Ismail Hakki , Kasnakoğlu Coşku
Published: September 2015

In this paper, we address the design of a controller that accomplishes stabilization and reference tracking at various flight conditions by using linear helicopter models. The suggested controller is in the form of an H-infinity gain-scheduler, and is used for stabilization and reference tracking for the 4 axis (heave, pitch, roll and yaw) autopilot. Based on the linear models given for the Puma helicopter, an approximate affine parameter dependent model has been built. Then, a linear parameter dependent controller is synthesized which stabilizes the affine parameter dependent helicopter model. By doing so, a single controller achieves stabilization and reference tracking of a family of linear models by scheduling the controller gains based on the online measurement of the scheduling parameter, which is the forward velocity. Moreover, the affine parameter dependent controller is fitted into the linear models. It is observed that this single parameter dependent controller successfully stabilizes a family of linear helicopter model at different forward flight conditions.
Sustainable Manufacturing Processes of Building Materials: Energy Efficiency
Authors: Öztaş Saniye Karaman
Published: September 2015

The increase of energy consumption has produced significant environmental impacts such as climatic change, acid rain, photo chemical smog formation, nonrenewable resource consumption etc. Considering the urgency of saving the world’s energy reserve and reduction of environmental impacts, studies on the energy consumption throughout the life cycle of building materials are crucial.In this study, it was aimed to indicate the factors which contribute the energy efficiency in manufacturing processes of building materials. The study included the energy used for raw material extraction, production energy for manufacturing of building materials, transportation energy and construction energy on site. A literature review was made. Energy use and efficiency for each process were evaluated.
The Study of the Multichannel Solar Chimney Ventilation Performance
Authors: Zhao Wen Bo , Lei Yong Gang , Wang Fei
Published: September 2015

This paper mainly put forward to the structure of the vertically multichannel solar chimney, which is the inbuilt endothermic triangle wall. According to the method of numerical simulation, it researched and explored the characteristic of ventilation in the vertically multichannel solar chimney. The purpose of this paper is to research the variation of air volume to the optimize structure on vertically solar chimney depend on different conditions, including aisle width, W and the radius of the endothermic semicircular wall, S. In addition, it makes a comparison on air volume between optimized and traditional solar chimney structures. The results show that the air volume of the solar chimney with endothermic triangle wall increased 18%-25.4% than traditional structures within the prescribed limits such as radius (100mm, 150mm, 200mm and 250mm) and heat flux (1000W/m2). While there is not an obviously change on the air volume of solar chimney with variations in radius.
Effects of Wetting on the Soil Fabric of Compacted Clay
Authors: Zaini Juliana Hj , Azad Abul Kalam , Abu Bakar Saifullah , Nam Cheok Quentin Hoon
Published: September 2015

Saturation-unsaturation process of compacted clay fill may lead to loss of shear strength and collapse compression or heave of the fill. These are the two main engineering problems associated with compacted clay fills and naturally before, granular based compacted fills are often employed at construction sites. Use of granular material for compaction may not be economical and sustainable. Therefore, a laboratory-based study was carried out to examine the structure of the compacted clay when used as backfill material. Several kaolin clay specimens prepared under similar condition were subjected to wetting with and without K0 control.
The Statistical Verification of Significance of Airtightness and Energy Performance
Authors: Kraus Michal , Kubeková Kateřina , Kubečková Darja
Published: September 2015

The main objective of the paper is to confirm or exclude a statistically significant impact of airtightness on the energy performance of buildings. Energy performance of buildings is characterized by a specific energy demand for heating and specific total primary energy. Airtightness is one of the key factors of energy efficient buildings. The quality of airtight building envelope except for low energy consumption also minimizes the risk of damage to the structure associated with the spread of the heat and water vapor in the structure.
Hard Spots in ADC12 Die Casting Cylinder Block Used for Air Compressor
Authors: Liu Yun , Hua Gao , Zhao Bin , Guo Bo , Chang Yi Jia , Zhou Yin , Zhao Zhen Bo , Zhang Qin , Liu Cheng
Published: September 2015

The hard spots are investigated in ADC12 die casting cylinder blocks for air compressors using metallographic method and a micro- hardness tester. The results show that the hard spots have two main shapes. There is a nonuniform micro-hardness distribution within a hard spot. Energy dispersive spectrometry (EDS) analysis reveals that these hard spots are some kind of mixture of oxide and carbide, which are formed during melting and die casting process.
A Roll Powder Sintering Additive Manufacturing Technology
Authors: Shulunov Vyacheslav R.
Published: September 2015

This paper describes the roll powder sintering (RPS) technology providing breakthrough advantages for dominant rapid prototyping and manufacturing (RP&M) processes that are currently on the market. The RPS based on ribbon perforation where a powder needs to be poured, while it is being rewound. When the whole component roll is rewound, it is ready for a sintering plant. This technology has increased reliability, higher precision up to 77000 dpi, lower cost and power consumption. Processing time of plastic, ceramic, metal and other objects 1 m3 (or more) in volume directly from a 3D CAD model with a layer thickness of 30 μm is about 1 hour.
Re-Layout and Robust Machine Layout Design under Stochastic Demand
Authors: Vitayasak Srisatja , Pongcharoen Pupong
Published: September 2015

In manufacturing business, variability in customer demand over time-periods has led to production flexibility on the shop floor area. Placement of machines in a limited manufacturing area is one of the essential plant designs in material flow between machines. Shortened material handling distance can be considered a key performance index of internal logistic activity in a manufacturing firm. This paper presents the application of the Genetic Algorithm for designing machine layouts that minimise total material handling cost based on demand uncertainty during time-periods. The experimental study was computationally conducted based on two scenarios: re-layout after demand changing; and robust layout (no machine movement even if demand changes). A trade-off between the shortened handling distance and total cost was discussed as being a business decision-making tool.
The Impact of Employing Different Quality PA2200 Powder Grades to Shrinkage on Sintered Part in Selective Laser Sintering Process
Authors: Yusoff W.A.Y. , Pham D.T. , Dotchev K.D.
Published: September 2015

One of the challenges which Laser Sintering faces is the Rapid Manufacturing of plastic parts with good consistent quality. This is due to the fact that plastic powder properties deteriorate during the long periods of time through the LS building and cooling cycles. This paper presents an experimental study of the deterioration or ageing of PA12 powder properties in the LS process. The influences of different grades of recycled PA12 powders are investigated. The main aim of this research is to develop a methodology of controlling the input material properties that will ensure consistent and good quality of the fabricated parts. From the experiment it was found that PA12 powder with high melt flow rate, low melting temperature, low glass transition temperature and low degree of crystallization temperature could improve the sintering process to produce a good Laser Sintering (LS) parts with lower shrinkage rate.
The Effect of Unforeseen Disruption on Different Types of Manufacturing Industry-Layout
Authors: Ikome J.M. , Ayodeji S.P. , Kanakana M.G.
Published: September 2015

Consistency and on timely delivery are among some of the factors that can keep a customer loyal and committed to a manufacturing industry. Almost all manufacturing facilities need to use production scheduling systems to increase productivity, reduce production costs and time. Most manufacturing industries invest huge amount of money to manufacture and supply products on time in order to meet customers demand and objectives but due to unforeseen disruptions, these objectives are difficult to achieve. In Real-life, production operations are subject to a large number of unexpected disruptions that may invalidate an original schedule. Being able to cope or react to these disruptions determines a company’s out-put and profitability. Productivity expression and simulation models are employed to assist in determining operational characteristics and also by comparing results from undisrupted system with that which is disrupted. These proposed models are tested on different tile manufacturing industry lay-outs in CMR and it is demonstrated that the leading source of disruption varies with different industry-layout and geographical regions. The study revealed that, the most common cause of disruption are power failure, machine breakdown, advert whether and employees absenteeism).This can be concluded from an industrial engineering point of view that, disruption during tile manufacturing is the main cause of low productivity or out-put in CMR tile manufacturing industries.
Study of Interfacial Shear of Aluminium/Oil Palm Empty Fruit Bunch Fiber Reinforced Polypropylene Fiber Metal Laminates
Authors: Hussain Nur Fadzila , Sivakumar D. , bin Daud Mohd Ahadlin , Sivaraos  , Selamat Mohd Zulkefli
Published: September 2015

This paper examines the interfacial shear properties of a new fiber metal laminates based on oil palm fiber reinforced polypropylene. The adhesive shear strength based on two type of surface treatment technique had been studied to determine the best technique to ensure a good bonding for fiber metal laminates based on oil palm empty fruit bunch fiber reinforced polypropylene (EFB pp) composite and aluminium 6061. Adhesion between aluminum and EFB pp composite was achieved by incorporating modified polypropylene adhesive film and surface treatment of Al sheets. Differential Scanning Calorimetry test showed the suitable bonding temperature between the composite and glue to be between 140°C to 155°C which is lower than the melting temperature of polypropylene. The applied surface treatment of ethanol solvent wipe and NaOH chemical etch though have effect on the surface roughness but have no significant effect on the maximum adhesion shear stress. The modified polypropylene adhesive film selected for this work is suitable to bond EFB pp composite with aluminium 6061 and both surface treatment is equally suitable.
Research of Elliptic Ultrasonic Vibration Mechanism
Authors: Sun Tian Xing , Chen Ming Fang , Sun Qi , Zhang Yong Xia
Published: September 2015

Elliptical vibration cutting is a new processing technology of work piece surface texture generation, the technique based on conventional cutting machine main movement and feed motion of the tool, by changing the structure so that the tip motion to generate ellipse trajectory. This paper designed incentive range vibration frequency as 20~40 KHz, can generate elliptical vibration trajectory in the small space of X/Z axis 16um. Tests prove that, the ultrasonic elliptic vibration cutting mechanism improves the specimen surface texture, smooth discharging of chipping, greatly improving the surface finishes of the work piece.
Raman Analysis of Vanadyl Phthalocynine Layers for Plastic Electronic Applications
Authors: Paez-Sierra Beynor Antonio , Mesa Fredy , Dussan Anderson
Published: September 2015

Engineering, stability and orientation of semiconducting molecules are necessary to achieve the high efficiency of multifunctional organic-based devices. Several conjugated molecules facilitate the use of external magnetic fields to tailor both their molecular orientation and electronic properties while being processed for bio or opto-electronic applications. In this work, molecular thin films of vanadyl phthalocynine (VOPc) layers forming conducting channels in organic field-effect transistors were investigated. Three systems based on 100 nm thick VOPc thin film were grown, one in absence of magnetic field, while the other two with parallel and perpendicular to the substrate plane, respectively. Devices were ex-situ investigated by electrical characterization and confocal scanning Raman spectroscopy (SRS). All molecular layers growth on Au electrodes presented enhancement of the Raman signal.
Topology Optimization of Wing Structure with Manufacturing Constraints
Authors: He Dan , Lin Chun Jing , Deng Yang Chen
Published: September 2015

A methodology and a procedure for topology optimization of wing structure based on manufacturing constraints were proposed. By the methodology and procedure proposed, topology of thin-box wing structure which is easier manufactured than traditional topology result can be obtained. The manufacturing constraints of draw direction, member size control and inexcusable initial design were introduced into the optimal procedure and executed in Optistruct. Effect and efficiency were analyzed and compared with traditional topology optimization.
Fatigue Finite Element Analysis of Certain Type of EMU Gearbox Box
Authors: Zhang Jiao , Li Xi , Xie Hao
Published: September 2015

EMU gearbox is a key component of high-speed train, the reliability of the gearbox will directly affect the operational safety of EMU. The box of EMU gearbox is with light alloy materials, bearing structure, so the box is subjected to greater loads and shock and vibration. Designers most take into account the static strength and stiffness of the box, ignore the fatigue failure. Fatigue failure is the leading cause of mechanical structural failure, while the peak load cycle fatigue failure is often far less than estimated in accordance with the static fracture analysis "safe" load, so the EMU gearbox box’s fatigue analysis is needed. Combining high-speed EMU gearbox actual operating conditions, using finite element method to do fatigue analysis of the gearbox box while the analysis result is evaluated and amended by the Smith schematic analysis method.
Modified Stoney's Equation for Evaluation of Residual Stresses on Thin Film
Authors: Chen Kuen Tsann , Chang Jui Hsing , Wu Jiun Yu
Published: September 2015

In the article, a simple method for the modification of the Stoney's equation was presented. The Stoney's equation is proposed from the assumption of equi-biaxial residual stresses in thin films. In this present method, biaxial stresses are different in x-axis and y-axis on thin film. The location of neutral axis depends on the material parameters and the film thickness. The finite element method (FEM) was used to simulate the thermal stress on the thin film. The results of the modified methods are compared with the results of FEM and other literatures. The present method is more accurate than the Stoney's equation in the evaluation of such films.
Thermal Error Prediction of the Spindle Using Adaptive Neuro-Fuzzy Inference System
Authors: Li Yan Lei , Wang Ming Yan , Hu You Min , Wu Bo
Published: September 2015

This paper proposes a new method to predict the spindle deformation based on temperature data. The method introduces ANFIS (adaptive neuro-fuzzy inference system). For building the predictive model, we first extract temperature data from sensors in the spindle, and then they are used as the inputs to train ANFIS. To evaluate the performance of the prediction, an experiment is implemented. Three Pt-100 thermal resistances is used to monitor the spindle temperature, and an inductive current sensor is used to obtain the spindle deformation. The experimental results display that our prediction model can better predict the spindle deformation and improve the performance of the spindle.
Research on Inspection Feature Recognition Based on Pro/E
Authors: Duan Gui Jiang , Ren Ye , Duan Hua
Published: September 2015

Inspection feature recognition is one of the key technologies to realize system integration of CAD/CAIP. To improve the integration between design and inspection, an inspection feature recognition system is developed based on Pro/TOOLKIT and VS2008. The component factors of inspection feature were discussed in this paper, and the flow of inspection feature recognition was introduced. Finally, with a case study, the feasibility and applicability of the method was verified.
A Numerical Investigation of Laminar Mixed Convection Flow and Heat Transfer in a Lid Driven Cavity with Two Cylinders
Authors: Khanafer Khalil , El Haj Assad M.
Published: September 2015

Mixed convection flow and heat transfer characteristics in a lid-driven cavity with two isothermally heated circular cylinders inside are studied numerically using a finite element formulation based on the Galerkin method of weighted residuals. The top lid of the cavity is moving rightwards with a constant speed. The two cylinders are maintained at an isothermal hot temperature, while the walls of the cavity are maintained at a cold temperature. Comparisons of streamlines, isotherms and average Nusselt number are presented to show the impact of the Richardson number, non-dimensional radius of the cylinder, and the location of the cylinders on the transport phenomena within the cavity. The results of this investigation show that the presence of the cylinders results in an increase in the average Nusselt number compared with a case with no cylinder. The average Nusselt number increases with an increase in the Richardson number for all non-dimensional radius of the cylinder studied in this work. It is seen that changing the boundary condition on one of the cylinders from isothermal to adiabatic has minimal effect on the average Nusselt number around the walls of the cavity.
Numerical Simulation of Radiation Losses in a Decaying Laser Spark Using LBL Method
Authors: Sharma Ankit , Bansal Ankit , Kishan Anil , Joarder Ratan
Published: September 2015

An investigation has been done to numerically simulate the radiation losses which occur due to laser energy deposition in a domain. Although the fluid dynamic effects due to laser energy deposition has been studied by a number of researchers independently but the effect of radiation has either been neglected or has not been highlighted effectively. When laser energy is deposited in a domain, very high temperatures are reached. At such high temperature, the diatomic air species may become highly dissociated and emission from the resulting two mono atomic species N and O cannot be neglected and is the major source of radiation loss. An Open Source CFD software Open Foam has been used to study the above effects. P1 radiation model along with radiation Line by Line method has been used to calculate the radiation losses. Radiation losses obtained are 20 times higher as compared to the only one past reported data but still are negligible as compared to the deposited energy. Hence our study validates the assumption of neglecting radiation losses, which was assumed earlier in all previous studies without any proper validation, using the most accurate LBL method.
The Impact of Different Axial Oil Chamber Design on Hydrostatic Spindle
Authors: Chen Shao Hsien , Chen Shang Te , Hsu Chien Cheng
Published: September 2015

High-precision machining and large-scale tool are the most primary development trend of current machine tool and hydrostatic products are key technologies of high-precision machining equipments. However, these equipments mostly process miniature components, thus the adopted tools are relatively small and the spindles mainly use are mainly built-in types of HSK32 to HSK25 with revolutions speed over 25,000rpm. Some processing equipments are even equipped with hydrostatic or gas-static spindles. The study extends the axial oil chamber to radial ones to expand the action area of axial oil pressure and form a closed oil seal edge by combining the radial clearance. Consequently, the axial bearing stiffness can be enhanced to enlarge the application scope of hydrostatic spindle. The design mode can enhance axial stiffness of spindle modules or strengthen the stiffness of hydrostatic spindle in a ball screw.
Finite Element Modeling of Frictional and Material Anisotropy During Forming of Steel Cylindrical Cups
Authors: Trzepiecinski Tomasz , Bazan Anna , Lemu Hirpa G.
Published: September 2015

The article presents a method of determining the anisotropic friction model in metal forming using multilayer artificial neural networks based on experimental data obtained from the pin-on-disk tribometer. The experimental results show that the friction coefficient depends on the measured angle from the rolling direction and corresponds to the surface topography. Both the friction and material anisotropic models were implemented into a finite element (FE) model built using the commercial FE-package ABAQUS/Standard. When both the material and friction anisotropy are taken into account in the finite element analysis, this approach gives the most approximate numerical results to real processes.
Study on the Structure Parameters Simulation and Optimization for Stamping Quality of Plate Heat Exchanger
Authors: Wang Jin Wu , Chen Si , Chi Rui Feng , Zhao Xi Lu
Published: September 2015

CAD / CAE model of plate structure is designed for plate heat exchanger provided by the manufacturer. Stamping process of the plate is simulated using Dynaform which is the special software of numerical simulation for sheet metal. The quality of plate stamping is analyzed by thinning rate, forming limit diagram (FLD) and other indicators, and compared with practical problems. At the same time, twelve levels experiments programs including ripple inclination, ripple normal pitch and ripple height are established according to uniform design principles based the parameters of ripple structure provided by manufacturer, and twelve chevron ripple plate models is established and their forming quality is analyzed with Dynaform Software. Influence and laws of plates three structural parameters, plates’ section parameters , BHF for stamping quality are studied and summarized, and the optimal choice of the plates is fond out to provide a theoretical basis for the actual production.
Analysis and Optimization of Erosion Wear Tester Design Parameters
Authors: Kosa Ergin , Göksenli Ali
Published: September 2015

Erosive wear is defined as material loss from surface due to impact of liquid and solid particles. This mechanism can be seen widely in the industry such in mining, valves, pipe and pump systems. Characteristics and wear amount of erosive wear is affected by different parameters like geometry, impact speed, impingement angle of the hard particles, solid-liquid rate, material hardness and toughness. To determine the effect of these parameters on erosive wear, a wear slurry tank is designed. Before the prototype design of the test tank, different geometrical parameters of the tank are analyzed using simulation software. By computational investigations, the 3-D flow in a liquid/solid (slurry) tank is established and analyzed. Aim of the mathematical analysis was to detect the effect of the tank design parameters on liquid impact velocity and distribution on the test specimen surface. According to the results, geometrical parameters of the tank such as; baffle width, propeller length, assembly position of the specimens in the slurry tank, the distance between the propeller and specimens are defined.
Numerical Investigation of Cavity Flow Field Characteristics in Supersonic Flow
Authors: Liu Yi , Dou Zhi Guo , Duan Li Wei
Published: September 2015

The cold flow field in a two dimensional cavity of supersonic combustor has been simulated numerically by using the compressible flow Navier-Stokes equation with the κ-ω SST turbulence model. The flow field structure of different cavity aft wall slope angle (16°,30° and 90°) , different fore aft wall height ratio (1 and 2) and different length depth ratio (3 and 5) are analyzed. The conclusions are as follows: As cavity aft wall slope angle decreases, the compression wave formed at cavity leading separation corner shifts into expansion wave, the shear layer moves into cavity gradually; As cavity fore aft wall height ratio increases from one to two, the expansion wave formed at cavity leading separation corner strengthens and there is no compression wave formed at;As cavity length depth ratio increases from three to five, the compression or expansion wave formed at cavity leading separation corner weakens, cavity bottom wall pressure tends to be constant and aft wall pressure rises.
Study of the Mixed Convection in a Horizontal Channel Heated from below
Authors: Sahraoui N. Mahfoud , Houat Samir , Saidi Nawal
Published: September 2015

In this work, a contribution to the modeling and numerical simulation of mixed convection in a horizontal channel heated from below is presented. The lattice Boltzmann model with double thermal populations (TLBM) is used with the D2Q9 model for the dynamic field and D2Q5 for the thermal field. A comparison of the results obtained by the lattice Boltzmann model with those of the literature is presented for an area stretching ratio B = H / L = 20, a Reynolds number Re = 10, Rayleigh Ra = 104 and Peclet number Pe = 20/3. The streamlines and isotherms are presented for different periods of flow.
Natural Convection in an Annular Porous Medium: Effect of Brinkman Correction on the Bifurcation Point
Authors: Belabid Jabrane , Cheddadi Abdelkhalek
Published: September 2015

This work presents a numerical investigation of the natural convection in a saturated porous medium bounded by two horizontal concentric cylinders, modeled taking into account the Brinkman term. The governing equations (in the stream function and temperature formulation) were solved using the ADI (Alternating Direction Implicit) method. The results obtained for the bifurcation point are in a good agreement with the available published data for Da≈0. A study of the effect of Darcy number on the bifurcation point is conducted.
A Differential Quadrature Method for Solving Multi-Dimensional Inverse Heat Conduction Problem
Authors: Chen Kuen Tsann , Chang Jui Hsing , Wu Jiun Yu , Lin Meng Ju
Published: September 2015

In this paper, the differential quadrature method (DQM) is applied to evaluate the multi-dimensional inverse heat conduction problem (IHCP). The DQM is employed to discretize space domain, and the forward difference method is employed to discretize time domain. Three examples show that the numerical method is accurate. When the noise is added to the exact temperature, the DQM is still a stable and accurate method. Our numerical results are compared with other literatures and show that the method achieves higher accuracy than other methods. Therefore, a simple, convenience, and stable method for evaluate inverse problem is obtained.
The Simulation of Molecular Return Flux in Thermal Vacuum Test of Spacecraft
Authors: Jiao Zi Long , Jiang Li Xiang , Sun Ji Peng , Huang Jian Guo , Zhu Yun Fei
Published: September 2015

In process of thermal vacuum test of spacecraft, the molecular contamination can have severe effects on performance and reliability of optical payload. In this article, we analyzed the contamination transport mechanism, simplified boundary conditions and input parameters based on physical understanding. We employed the Direct Simulation Monte-Carlo method to simulate the return flux of molecular contamination scattered by residual gas molecules in thermal vacuum tests of solar array and whole satellite. The results of simulation show that the return flux cannot be ignored, and its highest value would be 0.004. This would help the contamination control of spacecraft design, manufacture, test, and on-orbit operation.
Significant of Isothermal Flow Studies for High Swirling Flow in Unconfined Burner
Authors: Norwazan A.R. , Mohd Jaafar M.N.
Published: September 2015

This paper is presents numerical simulation of isothermal swirling turbulent flows in a combustion chamber of an unconfined burner. Isothermal flows of with three different swirl numbers, SN of axial swirler are considered to demonstrate the effect of flow axial velocity and tangential velocity to define the center recirculation zone. The swirler is used in the burner that significantly influences the flow pattern inside the combustion chamber. The inlet velocity, U0 is 30 m/s entering into the burner through the axial swirler that represents a high Reynolds number, Re to evaluate the differences of SN. The significance of center recirculation zone investigation affected by differences Re also has been carried out in order to define a good mixing of air and fuel. A numerical study of non-reacting flow into the burner region is performed using ANSYS Fluent. The Reynolds–Averaged Navier–Stokes (RANS) realizable k-ε turbulence approach method was applied with the eddy dissipation model. An attention is focused in the flow field behind the axial swirler downstream that determined by transverse flow field at different radial distance. The results of axial and tangential velocity were normalized with the U0. The velocity profiles’ behaviour are obviously changes after existing the swirler up to x/D = 0.3 plane. However, their flow patterns are similar for all SN after x/D = 0.3 plane towards the outlet of a burner.
Synthesis and Investigation of the Structural Properties of Al3+ Doped Mg Ferrites
Authors: Hossain Shahzad , Hasan Mohammad Kamrul , Yunus S.K. Md. , Zakaria A.K.M. , Datta Tapash Kumar , Azad Abul Kalam
Published: September 2015

The polycrystalline ferrites of MgAlxFe2-xO4 (0.0≤x≤0.4) were prepared by the conventional solid state ceramic method. The specimens were sintered at 13500C and X-ray diffraction experiments were done at room temperature which showed single phased cubic spinel structure. The lattice parameters were determined from the XRD data using Nelson-Riley extrapolation method and found to decrease with increasing Al concentration obeying Vegard’s law. The cation distribution and oxygen position parameters have also been determined by refining the data using the RIETAN-2000 in the Rietveld method which reveals that the samples possess cubic symmetry corresponding to the space group Fd-3m. The X-ray density and bulk density of each sample were calculated using the lattice parameters. The porosity has been determined from X-ray density (ρx) and bulk density (ρB) and it changes monotonically with Al content.
Experimental Analysis of the Pool Boiling Phenomenon of Sugarcane Juice
Authors: Marcelo Daniel , Yacila Paul Villar , La Madrid Olivares Raúl
Published: September 2015

In Peru, jaggery making process has low energy efficiency and it is due to low heat transfer coefficients for natural convection linked to the sugar cane movement generated by the heat exchange between the sugarcane juice and the combustion gases. This low heat transfer coefficients are caused by improper heat exchangers designs. In this work, is performed an experimental analysis that consist in supplie heat to a pot containing sugarcane juice using a hot plate of constant electrical power. This study consist in identify boiling regimes and estimate the heat transfer coefficients linked to natural convection boiling, measuring: (i) the temperature at the bottom of the pot (ii) the temperature at the bottom level of sugarcane juice (iii) the temperature at middle level of sugarcane juice (iv) the temperature at free surface of sugarcane juice (v) rate of water evaporated. The method of linear regression and the correlation of Rohsenow were used for obtaining the values of the heat transfer coefficients ranging from 4088.6 W/m2°C to 12592.8 W/m2°C with power input ranging from 700W to 1300W.
Dew Point Measurement Error due to Tube Length in a Calibration Instrumentation and the Evaluation of Measurement Uncertainty
Authors: Bae Yun Kyung , Hyun Dong Hoon
Published: September 2015

The purpose of this paper is to analyze the effect of tube length in calibration instrumentation on dew point measurement of dew point sensors (DPS) and evaluation of measurement uncertainty. When measuring dew point temperature, various tube lengths between dew point generator and dew point sensor (DPS) cause a significant error due to moisture absorption of inner tube. The measurement is carried out to analyze the variation on measured dew point temperature for four cases of tube lengths with 300 mm, 1200 mm, 2500 mm and 5000 mm. The dew point temperature measurements were performed in the range from-60 °C to 10 °C by using calibrated standard chilled mirror hygrometer as reference standard. In order to investigate contribution to the standard uncertainty for the tube length variation as an uncertainty source, expanded uncertainties were evaluated for the cases including the effect of tube length variation as an uncertainty source and excluding it at each measurement point. The measurement was conducted according to standard calibration procedure of Korea Testing Laboratory which assures suitability and traceable results. It is also based on international standards.
Research on Automatic Programming and Process Diagnosis in On-Machine Measurement
Authors: Duan Gui Jiang , Gao Shuai , Cui Zhang Dong
Published: September 2015

Automatic programming and process diagnosis are the essential function to drive the Numerical Control (NC) machine tool with probes to measure the products and evaluate the quality of process in every inspection procedure based on on-machine measurement (OMM), especially in the complex parts measuring, which can avoid the products unqualified and promote the efficiency of manufacture and inspection. In this paper, the method of automatic programming, the data exchange of measurement and the principle of process diagnosis are discussed. With a practical case based on FANUC, the effectiveness and efficiency of the method raised in this paper is validated.
Solder Ball Robustness Comparison between SAC 387 and Polymer Solder Balls under AC and TC Reliability Test
Authors: Yap Boon Kar , Tan Cai Hui , Tan Chou Yong
Published: September 2015

Environment and the health concerns due to the hazardous effects of lead resulted in significant activities to find a replacement for lead-contained solders for electronics industrial. Majority of the semiconductor industrial are now replacing lead solders with Tin-Silver-Copper (SAC 387) solder balls. However, dropped balls in SAC 387 for Ball Grid Array (BGA) products due to poor solder joint strength caused by high thermal stress are a major concern in the semiconductor industries. Polymer core inside the solder ball (polymer core/Cu/Sn) is thus integrated to improve the solder ball joint strength. The function of polymer core inside the solder ball is to absorb and released the stress better as compared to the SAC 387 solder ball. Since the diffusion rate of Cu is faster than the diffusion rate of Sn, hence, this could caused the Kirkendall voids tends to form in between the Cu and Sn IMC layer. This would affect the solder ball joint strength and causing drop balls issue. By implement with an extra of Ni layer to the polymer core solder ball (core/Cu/Ni/Sn), could reduce the diffusion from Cu to Sn, thus to overcome the Kirkendall voids and to further improve the solder ball joint strength. This research work studies the performance of the solder ball shear strength of the two types of solder balls applied to MAPBGA device. In this research, both SAC 387 and polymer solder balls were went through under AC (Autoclave) and TC (Temperature Cycle) reliability test up to 144 hours and 1000 cycles, respectively. Solder ball shear strength test was conducted via Dage 4000 series bond tester. From the research work results of the two types of solder balls, the ball shear strength were decreased with an increased of aging and cycles. Overall, it can be concluded that the polymer core solder ball with an additional of Ni layer showed better performance than the polymer core without Ni layer and SAC 387 solder balls, after subjected to the AC and TC reliability test.
A Low Cost Robotic Wheelchair System Using a Pan-Tilt Camera and a Visual Marker
Authors: Kim Bong Keun , Tanaka Hideyuki , Sumi Yasushi
Published: September 2015

In this paper, a low cost robotic wheelchair system with only a pan-tilt camera is explained. In order to reduce the development cost, an electric wheelchair using a visual marker which is capable of achieving a high level of precision in positioning an electric wheelchair without geometric features is proposed. Then, indoor navigation methods are explained, which enable automatic and hybrid navigation of an electric wheelchair with only a pan-tilt camera. Finally, experiment results obtained by considering a particular scenario for indoor navigation reveal the feasibility of the proposed robotic wheelchair system.
Mechanical Analysis of a Hybrid Approach for a Lower Limb Rehabilitation Robot
Authors: Wanichnukhrox Nakrob , Maneewarn Thavida , Songschon Szathys
Published: September 2015

The design of lower limb rehabilitation robot can be categorized into two approaches: the end-effector and the exoskeleton. Both types of the robots have different advantages and disadvantages. The exoskeleton type is designed to mimic the kinematic structure of the human skeleton by controlling hip and knee joints but the end-effector type is driven at the footplate which allows patients to perform various gait training exercise. In this paper, the end-effector and exoskeleton device are compared based on dynamical analysis using Matlab's Simechanics simulation. The hybrid lower limb rehabilitation robot is also proposed based on the exoskeleton robot with the adjustable mechanical coupling interface between human and robot and the active footplate. The hybrid design combines the advantages of both the exoskeleton and the end-effector by allowing the mechanical coupling parameters and the active footplate controller to be adjustable at different stages of training. The proposed design can improve both joints misalignment and joint trajectory tracking problems in both existing approaches.